*Article* **Alcohol Deprivation Differentially Changes Alcohol Intake in Female and Male Rats Depending on Early-Life Stressful Experience**

**Marielly Carvalho 1,2,†, Gessynger Morais-Silva 3,4,†, Graziele Alícia Batista Caixeta 1,2, Marcelo T. Marin 3,4 and Vanessa C. S. Amaral 1,2,\***

**Abstract:** Experiencing early-life adverse events has enduring effects on individual vulnerability to alcohol abuse and the development of addiction-related behaviors. In rodents, it can be studied using maternal separation (MS) stress. Studies have shown that, depending on the protocol used, MS can affect the mother and pups' behavior and are associated with behavioral alterations later in adulthood, associated with both positive or negative outcomes. However, it is not fully elucidated how MS affects relapse-like behaviors when experienced by female or male individuals. Therefore, the aim of our study was to evaluate the effects of brief and prolonged MS on the alcohol deprivation effect (ADE) in female and male rats. Female and male Wistar rats were exposed to brief (15 min/day) or prolonged (180 min/day) MS from postnatal day (PND) 2 to 10. Later, during adulthood (PND 70), animals were submitted to an ADE protocol. Brief MS exposure prevented the ADE in both females and males, while prolonged MS exposure also prevented the ADE in female rats. Moreover, the ADE was more robust in females when compared to males. In conclusion, we showed that male and female rats are differentially affected by alcohol deprivation periods depending on their early-life experiences.

**Keywords:** addiction; maternal separation; risk factor; sex differences

#### **1. Introduction**

The main feature involved in alcohol addiction is the neuroplasticity that undergoes the neurocircuitry related to motivation, habit, learning, and cognitive control. These neuroplastic events occur due to chronic drug intake and involve complex interactions with the environment and genetic factors [1]. Such long-lasting neuronal alterations are a crucial part of the most challenging step related to the treatment of addiction, namely relapse [2].

Given the pivotal role of neuroplasticity in the development of addiction, it is not surprising that early-life adverse events have enduring effects on individual vulnerability to alcohol abuse and the development of addiction-related behaviors [3]. A history of childhood maltreatment increases the incidence of alcohol use disorder (AUD) in adolescents [4] and adults [5,6] and is related to an earlier onset of drinking and alcohol abuse [7,8] and persistence of alcohol-related disorders through life [9]. Moreover, the greater the severity of the childhood abuse experienced, the greater is the impact on the prevalence and severity of the psychiatric disorders later in life [6,10]. Some studies highlight that such effects

**Citation:** Carvalho, M.; Morais-Silva, G.; Caixeta, G.A.B.; Marin, M.T.; Amaral, V.C.S. Alcohol Deprivation Differentially Changes Alcohol Intake in Female and Male Rats Depending on Early-Life Stressful Experience. *NeuroSci* **2022**, *3*, 214–225. https://doi.org/10.3390/ neurosci3020016

Academic Editors: Charles L. Pickens and François Ichas

Received: 22 February 2022 Accepted: 7 April 2022 Published: 9 April 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

could be sex-dependent since they are more prevalent in women [11,12]. Female and male rats exposed to early life stress show an early maturation of the connections between the basolateral amygdala and the medial prefrontal cortex, while this alteration occurs even earlier in females compared to males [13]. Female rats exposed to early life adversity also show an increase in serotonin metabolites in the ventral tegmental area compared to males [14]. Frontal cortex maturation occurs earlier in females than males [15].

Sex differences in alcohol drinking behavior and the incidence of AUD are extensively reported in the literature. In rodents, most studies show that ethanol intake in females is greater than males' [16–20], while men drink more and have a greater prevalence of AUD [21]. Although such data seems to be contradictory to rodent studies, human drinking behavior is largely influenced by social factors [22,23]. Moreover, recent reports are showing that women are drinking more, facing more problems with alcohol drinking, and women who drink excessively are more susceptible to the development of AUD than men [24].

The alcohol deprivation effect (ADE) is a broadly used rodent paradigm to study relapse-like drinking and has been exploited to the screening of possible candidates for the treatment of AUD relapse [25–27]. It consists of the chronic exposition to voluntary ethanol intake followed by periods of ethanol deprivation and re-exposure, resulting in a temporary increase in intake and preference [25]. The FDA (USA Food and Drug Administration) approved medications naltrexone and acamprosate, block the ADE in rodents, and are used for the treatment of AUD in humans [28–30].

Maternal separation (MS) is an animal model widely used to study the effects of early-life stress on alcohol intake and abuse. It relies on the importance of the pups-mother relationship, especially during the first two weeks (at least in rodent models) and, can be roughly separated into two main categories: the brief and prolonged MS [31]. These conditions affect the mother and pups' behavior and are associated with behavioral alterations later in adulthood, associated with both positive and negative outcomes, depending on the protocol used [31–33]. In the brief MS, the pups are kept apart from their dams for short time intervals (usually 3 to 15 min), which mimics the natural environment of these animals (in situations such as dams leaving the nest to go after food, for example). In prolonged MS, the pups are separated from their dams for prolonged time intervals (from 60 min to 24 h) [34]. While the brief MS has been associated with positive behavioral outcomes, reducing the effects of stress exposure later in life [33], the prolonged MS has been associated with negative outcomes, increasing the stress reactivity later in life [35].

In animal models, a history of early-life stress also seems to impact the individual vulnerability to addiction-related behaviors and alcohol abuse. As well as for stress responses, such effects are highly dependent on the protocol used. Most of the studies have shown that the brief MS seems to decrease while the prolonged MS increases ethanol intake in rats when the animals are tested in adult life [16,31,36–38]. Prolonged MS also increases the impulsivity for alcohol consumption in adult rats [39] and the ethanol conditioned place preference (CPP) acquisition in adolescent rats, while it does not impact CPP in adult rats [16]. However, there are no studies examining MS effects on animal models of ethanol intake relapse. Thus, considering the importance of the relapse behavior to understanding ethanol addiction and to the development of treatment strategies, we studied the effects of brief and prolonged MS on the alcohol deprivation effect, a rodent model for the study of ethanol intake relapse [25] in female and male rats.

#### **2. Materials and Methods**

#### *2.1. Animals*

Female and male Wistar rats from the State University of Goias were used for mating and as experimental animals. Experiments were carried out according to the principles and standards of the National Council for the Control of Animal Experimentation (CONCEA), based on NIH Guidelines for the Care and Use of Laboratory Animals as approved by the Commission on Ethics in Animal Use (CEUA) of the State University of Goias (protocol number 008/2016).

Forty-five adult Wistar rats (females: n = 30; males: n = 15) were used for mating. Primiparous females were mated with adult males in a 1:1 ratio, and gestation day 0 (GD0) was defined as the day when copulatory plugs and/or sperm were found. Pregnant rats were kept alone during gestation and checked daily for newborn pups.

Seventy-six Wistar rats (males: n = 39; females: n = 37) were used as experimental animals. After weaning (postnatal day 21 - PND 21), they were kept in groups of 3–5 animals/cage, until the beginning of the alcohol deprivation effect experiment (at PND 70), when they were individually housed. The females' estrous cycle was not pharmacologically synchronized.

Food and water were available *ad libitum* through the experiments. Animals were maintained in polypropylene cages (41 × 34 × 16 cm), under a 12 h light/dark cycle in a temperature-controlled environment (22 ± 2 ◦C).

#### *2.2. Maternal Separation (MS)*

The brief and prolonged MS was performed as previously described [16]. From PND 2 to 10, pups were daily separated from their dams for 15 minutes (brief MS – MS15) or 180 min (prolonged MS – MS180). During the separation period, the dams were transferred to clean cages and moved to a separate room, away from the pups. The pups were kept in their nests, under a red incandescent light, maintaining the temperature at 32 ± 2 ◦C. Weaning was normally performed at PND 21. The control group was kept undisturbed with the dams (except for cage cleaning) until weaning. To avoid any bias related to the litter, a maximum of two pups of each sex, from each dam, were used in each experimental group.

#### *2.3. Alcohol Deprivation Effect (ADE)*

The ADE protocol was adapted in our laboratory from the previously described [40]. Starting on PND 70, animals were exposed, for two days, to two bottles containing ethanol (6%) as the only source of fluid. Next, animals were given free access to two bottles, one bottle containing crescent ethanol concentrations (6, 8, and 10%) and one containing filtered water, for 4 days each concentration. This phase was called habituation and was intended to initiate alcohol drinking and habituate animals to the taste of the ethanol and experimental procedure. The ethanol consumption of each concentration was analyzed separately and identified as follows: ETOH 6% phase, ETOH 8% phase, and ETOH 10% phase. After that, baseline consumption was recorded: animals were given free access to two bottles, one containing ethanol (10%) and one containing filtered water for 10 days. Baseline consumption was considered as the average of the 4 days before the beginning of the deprivation phase (days in both male and female control groups with less than 20% variation from the average intake of ethanol 10%).

The next day after the baseline consumption phase, animals were submitted to the alcohol deprivation phase. Each deprivation period was comprised of 14 days of alcohol deprivation when only one bottle containing water was available followed by 7 days of free access to one bottle of 10% ethanol solution and one containing filtered water. The ADE was analyzed using the average consumption of four days after the end of each deprivation period. The animals were submitted to two deprivation periods. The experimental procedure indicating each ethanol exposure and deprivation phase is depicted in Figure 1.

Ethanol solutions (*v*/*v*) were prepared from absolute ethanol (Neon Comercial, São Paulo, SP, Brazil) diluted in filtered water and offered in plastic bottles fitted with stainless steel sipper tubes with ball-valve nipples in rubber stoppers. Ethanol and fluid intake was measured by weighing the bottles and reported as relative to body weight (g/kg). Liquid loss by leakage or evaporation was accessed using bottles placed in empty cages and was subtracted from the amount consumed by each animal.

Solutions were prepared fresh every day and presented to the animals at the same time. The position of the bottles was alternated every day to avoid side preference.

**Figure 1.** Experimental procedure timeline. Female and male rats were exposed to brief or prolonged maternal separation during early life and submitted to an alcohol deprivation effect protocol during adulthood. PND, postnatal day; ETOH, ethanol.

#### *2.4. Statistics*

Values were expressed as mean ± SEM and analyzed by repeated-measures ANOVA considering the independent factors sex and MS and the repeated measure phases. When ANOVA showed significant differences (*p* ≤ 0.05), the Newman-Keuls *post hoc* test was performed.

Statistics were performed using Statistica 7.1 software (StatSoft, Inc., Tulsa, OK, USA) and graphs constructed using GraphPad Prism 7 software (GraphPad Software Inc., La Jolla, CA, USA).

#### **3. Results**

#### *3.1. Ethanol Intake Prior to Deprivations*

We found a significant difference in ethanol intake before deprivations, related to the sex and the phase of the experiment, but not MS (Figure 2).  The Newman-Keuls test revealed that females consumed more ethanol than males in all phases of the experiment before deprivations (*p* < 0.001). In males, ethanol intake during the baseline phase was increased when compared to ethanol consumption in ETOH 6% phase (*p* < 0.001). In females, ethanol consumption during the ETOH 10% phase was the greater prior deprivations (*p* < 0.05), while baseline ethanol intake was increased when compared to ethanol intake during ETOH 6% (*p* < 0.01) and ETOH 8% phases (*p* < 0.05).

#### *3.2. Alcohol Deprivation Effect*

Alcohol deprivation differentially affected the ethanol consumption in males and females, depending on the early-life experiences (brief or prolonged MS) (Figure 3A and B).

Control males showed an increase in ethanol consumption only after the second deprivation (*p* < 0.05) compared to baseline. MS180 male group, similar to control males, showed a significant increase in ethanol consumption only after the second deprivation (emphp < 0.001) compared to baseline intake, while the MS15 male group did not show significant alterations in ethanol consumption after neither the first or second deprivation phases relative to baseline (Figure 3A).

**Figure 2.** Ethanol intake before deprivations in female and male rats exposed to brief and prolonged maternal separation. Bars represent the mean ± SEM (n = 11–14 animals/group). Each concentration represents the average intake of the 4 days of exposition in each experimental phase of the procedure. x; *p* < 0.05 when compared to female groups of the same experimental phase, independent of manipulation; a, *p* < 0.05 when compared to the ETOH 6% phase of the same sex, independent of manipulation; b, *p* < 0.05 when compared to ETOH 8% phase of the same sex, independent of manipulation; c, *p* < 0.05 when compared to ETOH 10% phase of the same sex, independent of manipulation. ETOH, ethanol; MS15, brief maternal separation; MS180, prolonged maternal separation.

Control females showed an increase in ethanol consumption after either the first (*p* < 0.01) or second deprivation (*p* < 0.001) compared to baseline. Ethanol intake after the second deprivation was also greater than ethanol intake after the first deprivation (*p* < 0.01). Both MS15 and MS180 female groups did not show any significant alterations in ethanol consumption after neither the first or second deprivation phases. Additionally, ethanol consumption of the control female group was greater than the MS15 female group (*p* < 0.05), MS180 female group (*p* < 0.05) and control male group (*p* < 0.05) after the second deprivation (Figure 3B).

We also found significant alterations in ethanol preference (Figure 3C,D).

Control males showed an increase in ethanol preference only after the second deprivation compared to baseline (*p* < 0.001) and after the first deprivation (*p* < 0.05). MS180 male group, similar to control males, showed a significant increase in ethanol preference only after the second deprivation (*p* > 0.001) compared to baseline and after first deprivation (*p* < 0.05), while the MS15 male group did not show significant alterations in ethanol preference after neither the first or second deprivation phases relative to baseline (Figure 3C). Similar to control males, control females showed an increase in ethanol preference after the second deprivation compared to baseline (*p* < 0.001) and after the first deprivation (*p* < 0.01). MS15 and MS180 female groups did not show an increase in ethanol preference after neither the first or second deprivation phases. Ethanol preference of the control female group was greater than the MS180 female group (*p* < 0.05) after the second deprivation (Figure 3D).

**Figure 3.** Alcohol deprivation effect (ADE) in female and male rats exposed to brief or prolonged maternal separation. The ADE was analyzed using the average ethanol intake or preference of four days after the end of each deprivation period compared to the last four days of the baseline period. The animals were submitted to two deprivation periods. Bars represent the mean ± SEM (n = 11–14 animals/group). (**A**), male ethanol consumption (g/kg); (**B**), female ethanol consumption (g/kg); (**C**), male ethanol preference; (**D**), female ethanol preference. \*, *p* < 0.05 relative to the baseline ethanol consumption of the same gender control group; #, *p* < 0.05 relative to the ethanol consumption after the first deprivation of the same gender control group; &, *p* < 0.05 relative to the ethanol consumption after the second deprivation of the same gender control group; \$, *p* < 0.05 relative to the ethanol consumption of the control male group after the second deprivation. MS15, brief maternal separation; MS180, prolonged maternal separation.

#### *3.3. Fluid Intake*

There was a significant effect of sex and phase, independent of the MS, on fluid intake through the experiment (Figure 4).  Overall, female fluid intake was increased compared to males (*p* < 0.001). Moreover, fluid intake, independent of the sex or MS decreased through the experimental phases. In males, fluid intake in ETOH 10%, baseline, 1st re-exposure, and 2nd re-exposure phases was smaller than fluid intake in ETOH 6% and ETOH 8% phases, while fluid intake during 1st re-exposure was smaller than ETOH 10% phase. In females, baseline, 1st re-exposure, and 2nd re-exposure fluid intake were smaller than ETOH 6%, ETOH 8%, and ETOH 10% phases. The female fluid intake in ETOH 10% phase was smaller than fluid intake in ETOH 6% phase.

#### *3.4. Body Weight*

Body weight was evaluated through the different phases of the ADE protocol and reported as body weight gain in each period (Figure 5). First, we found a significant effect in initial body weight (Figure 5A) for the factor maternal separation (F2,69 = 5.06; *p* < 0.01) and sex (F1,69 = 567.40; *p* < 0.001). The post-hoc analysis revealed that males began the alcohol deprivation effect protocol heavier than females (*p* < 0.001), and both brief or prolonged maternal separation increased body weight in both males and females (*p* < 0.05). On the other hand, total body weight (Figure 5B) through the experiment was only affected by sex (F1,69 = 55.57; *p* < 0.001), revealing that males gain more weight than females over time (*p* < 0.001). Next, we evaluated the body weight gain in each phase of our protocol (Figure 5C). Body weight gain during baseline phase was affected only by sex (F1,69 = 4.21; *p* < 0.05), revealing a greater body weight gain in males compared to females (*p* < 0.05). During the first deprivation period, the two-way ANOVA revealed a significant effect for maternal separation (F2,69 = 5.51; *p* < 0.01) and sex (F1,69 = 35.44; *p* < 0.001), showing that males gained more weight during this phase (*p* < 0.001) and maternal separation increased body weight gain during the ethanol deprivation phase (*p* < 0.05). We found similar results for the first re-exposure phase: a significant effect for maternal separation (F2,69 = 10.88; *p* < 0.01) and sex (F1,69 = 7.19; *p* < 0.001), showing that males gained more weight during this phase (*p* < 0.001) and maternal separation increased body weight gain during the ethanol deprivation phase (*p* < 0.001). We found a significant effect only for sex during the second deprivation phase (F1,69 = 7.90; *p* < 0.01), when males gained more weight than females (*p* < 0.01). Finally, we found a significant effect for the interaction between maternal separation and sex (F2,69 = 7.63; *p* < 0.01) in the second re-exposure phase, while the post-hoc test did not reveal any significant differences.

**Figure 4.** Fluid intake through the experiment in female and male rats exposed to brief and prolonged maternal separation. Bars represent the mean ± SEM (n = 11–14 animals/group). Each concentration represents the average intake of the 4 days of exposition in each experimental phase of the procedure. x; *p* < 0.05 when compared to female groups, independent of the manipulation or experimental phase; a, *p* < 0.05 when compared to the ETOH 6% phase, independent of sex or manipulation; b, *p* < 0.05 when compared to ETOH 8% phase, independent of sex or manipulation; c, *p* < 0.05 when compared to ETOH 10% phase, independent of sex or manipulation. ETOH, ethanol; MS15, brief maternal separation; MS180, prolonged maternal separation.

**Figure 5.** Initial body weight and body weight gain through the experiment in female and male rats exposed to brief and prolonged maternal separation. Bars represent the mean ± SEM (n = 11–14 animals/group). (**A**), initial body weight (g). (**B**), body weight gain during the whole period of alcohol deprivation effect (g/kg). (**C**), body weight gain in different phases of the alcohol deprivation effect protocol (g/kg). Body weight gain was calculated as the difference between the body weight on the last day of the respective phase and the first day of the same experimental phase. x; *p* < 0.05 when compared to female groups, independent of the manipulation; z, significant effect of maternal separation, regardless of sex. MS15, brief maternal separation; MS180, prolonged maternal separation.

#### **4. Discussion**

Here we showed that male and female rats are differentially affected by alcohol deprivation periods depending on the early-life experiences (brief or prolonged MS). First, females naturally drink more when compared to males. In males, the ADE was evident only after the 2nd ethanol re-exposure, and brief MS exposure was able to prevent it. In females, the ADE emerged earlier, in the 1st re-exposure period, while both brief and prolonged MS exposure prevented the ADE.

As already reported, we found remarkable differences in alcohol consumption between females and males. In both mice and rats, studies using several animal models of voluntary ethanol consumption showed that females consume more ethanol than males [16–20]. In a recent study from our lab, we showed that such differences are influenced by the concentration of the ethanol solution offered to the animals [16]. On the other hand, in humans, opposite results have been reported in epidemiological studies: men's ethanol intake and AUD prevalence are greater when compared to women, although women's

AUD prevalence has been growing recently [21]. Such results give strength to the view that alcohol drinking in humans is strongly influenced by cultural factors and that the underrepresentation of female individuals in biomedical research has a profound impact on substance use disorders research [41].

Our results also revealed that female Wistar rats are more susceptible to ADE since the increased alcohol intake in females showed up sooner than in males. As cited before, there is evidence suggesting that women who drink excessively are more prone to the development of medical problems compared to men [24], despite the greater incidence of AUD in men. In animal models, the results are highly dependent on the protocol used and the behavioral outcome tested. In this context, female rats showed enhanced sensitivity to the rewarding effects of ethanol [42] and increased ADE [19,43]. On the other hand, male rodents show increased behavioral signs of ethanol withdrawal [44] and greater withdrawal-induced ethanol-seeking behavior compared to females [45].

Studies in rodents, using mixed-sex analysis, showed that the prolonged disruption of pups-mother contact during early-life increases ethanol binge drinking and voluntary ethanol consumption in operant self-administration paradigms performed later in life [39,46–48]. Prolonged MS also increases ethanol consumption in male rats tested during adulthood in the 2-bottle [36,49,50] or 3-bottle choice paradigms [16]. On the other hand, brief MS during early life usually decreases ethanol intake in adult male rodents [36,50]. Both brief and prolonged periods of MS increase voluntary ethanol consumption in female rats submitted to a 3-bottle choice procedure [16], while there is no effect of MS when ethanol consumption is evaluated using the 2-bottle choice procedure [51,52]. Here, we found a more complex effect: while, in males, brief MS blocked the ADE, both brief and prolonged MS prevented the ADE in females. To date, few studies looked for the effects of MS on the ADE, especially using female individuals in the experimental procedure. One study found that neither brief nor prolonged MS affected the increased ethanol consumption after periods of intermittent ethanol exposure [53]. However, in this study, the authors did not use an animal facility hearing or handled control without separation periods, making difficult the comparison between the studies.

We found interesting results regarding body weight gain through different phases of our ADE protocol. As expected, females gained less body weight compared to males, regardless of the experimental phase, since male Wistar rats are larger and have an increased growth rate from puberty onwards than female Wistar rats [54]. Interestingly, animals exposed to MS, independent of MS length and sex, showed increased body weight. Moreover, maternally-separated rats showed increased body weight gain during periods of increased stress, that is, the first deprivation and first ethanol re-exposure phases. It should be related to an increased stress sensitivity in animals exposed to early-life stressors [35].

The variation in the period when brain maturation occurs could be related to the MS sex differences found in our study. Females' prefrontal cortex and amygdala undergo maturation faster when compared to males [13–15] and thus are more likely to be affected by the MS during the postnatal period that we performed our experiments. Prefrontal cortex dendritic morphology is more susceptible to the effects of MS in females than in males [55]. In this sense, the prefrontal cortex and the amygdala are involved in alcohol craving and relapse for alcohol drinking [56].

Two variables presented in our study could have impacted our results: the singlehousing condition and the females' estrous cycle phase. First, social isolation is a known stressor for rodents and can affect voluntary ethanol intake [57,58]. This is an important limitation of our work since individual housing was necessary for the evaluation of ethanol intake. On the other hand, more recent works have been showing that social isolation does not impact consumption of ethanol solutions up to 10%, in both rats and mice [59,60]. Thus, the procedure used in our work should be taken into account when interpreting our results. Secondly, we did not evaluate the estrous cycle or synchronized females' cycle in our work. Literature reports have been showing that the estrous phase does not have a substantial impact on ethanol intake in rats [20], although it seems to influence

ethanol consumption microstructure [61]. It could be explained by the fact that ethanol administration itself disrupts the estrous cycle in rats [62,63]. Moreover, human studies are inconsistent regarding the correlation between the menstrual cycle phase and alcohol intake [64].

In conclusion, brief MS exerted a protective effect against the ADE in both female and male rats. Despite the increased susceptibility to the ADE shown by females, prolonged MS also prevented the ADE in females, revealing sex-dependent effects of MS in rats.

**Author Contributions:** M.C., G.M.-S. and G.A.B.C. performed the experiments. G.M.-S. analyzed the data and drafted the manuscript. M.T.M. and V.C.S.A. designed the study, supervised the project, and revised the manuscript for intellectual content. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Fundação de Amparo a Pesquisa do Estado de Goias (FAPEG/CNPq Programa Primeiros Projetos [201610267001023]).

**Institutional Review Board Statement:** Experiments were carried out according to the principles and standards of the Brazilian National Council for the Control of Animal Experimentation (CONCEA), based on NIH Guidelines for the Care and Use of Laboratory Animals as approved by the Commission on Ethics in Animal Use (CEUA) of the State University of Goias (protocol number 008/2016).

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


**7. References**

Bravado, P., Armesilla, A., Silva, A., & Porras, A. (2007). Apoptosis by Cisplatin Requires p53 Mediated p38*a* MAPK Activation through ROS Generation. *Apoptosis*, Vol.12, No.9, pp. 1733–1742.

400 Nitroxides – Theory, Experiment and Applications

for clinical use.

**Author details**

*Russian Federation*

09-03-01187).

**7. References**

York.

**Acknowledgement**

Vasily D. Sen', Alexei A. Terentiev and Nina P. Konovalova

Cisplatin. *J. Chem. Education*., Vol.83, No.5, pp. 728–734.

*Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka,*

This work was partly supported by the Russian Foundation for Basic Research (Project No.

Alderden, R.A., Hall, M.D., & Hambley, T.W. (2006). The Discovery and Development of

Blokhin, N.N., & Perevodchikova, N.I. (1984). *Khimioterapiya opukholevykh zabolevanii*

Bonetti, A., Leone, R., Muggia, F.M., & Howell, B. (Eds.). (2009). *Platinum and other Heavy Metal Compounds in CancerChemotherapy,* Humana Press, ISBN 978-1-60327-458-6, New

(*Chemotherapy of Neoplastic Diseases*), Meditsina, Moscow, (in Russian).

physicochemical properties, interaction with DNA, cytotoxicity *in vitro* and antitumor activity *in vivo* were studied. A limited correlation was found between the ability of new complexes to form adducts with DNA, thermal stability of these adducts and antitumor activity of the complexes. PNCs are characterized by features that distinguish them from platinum complexes with usual alkylamines. An antagonism of platinum and nitroxyl pharmacophore was observed in cell culture. As compared to cisplatin or satraplatin, structurally close nitroxyl derivatives are approximately 10 times less cytotoxic. This may be explained by a moderate inhibition of p53-dependent apoptosis due to the antioxidant properties of nitroxyl radicals. These *in vitro* findings do not correlate with *in vivo* data, and antitumor activities of some PNCs and cisplatin are approximately the same. The relatively slow development of resistance to PNCs and the presence of synergy for the combinations of PNCs and cisplatin imply the differences in the mechanism of antitumor action of cisplatin and PNCs. Due to antioxidant properties (Sen' et al., 2000), nitroxyls in PNCs may ameliorate side effects typical for cisplatin, such as nephrotoxicity and neurotoxicity. For example, nitroxyl derivative of daunorubicin, ruboxyl, has virtually no cardiotoxicity that limits therapeutical doses of the parental compound (Emanuel & Konovalova, 1992). Reduced side effects, in turn, contribute to the better survival and, as a result, the higher efficacy of tumor chemotherapy *in vivo*. Our and literature data show that nitroxyls are promising modulators of the activity of anticancer agents and, as such, could be approved

 http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=3&ND=3& adjacent=true&locale=en\_EP&FT=D&date=19820601&CC=US&NR=4332934A&KC=A.

Emanuel, N.M., Rosenberg, A.N., Golubev, V.A., Bogdanov, G.N., Vasil'eva, L.V., & Konovalova, N.P. (1985). 5-Fluorouracyl Nitroxyl Derivatives Possessing Antitumor Activity. *US Pat*. 4558127,

 http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=1&ND=3& adjacent=true&locale=en\_EP&FT=D&date=19851210&CC=US&NR=4558127A&KC=A.

Emanuel, N.M., Sen', V.D., Golubev, V.A., Bogdanov, G.N., Vasil'eva, L.V., & Konovalova, N.P. (1986). Nitroxyl Derivatives of Nitrosourea Exhibiting Antitumor and Mutagenic Activity. *SSSR Pat*. 1259650,

 http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=8&ND=3& adjacent=true&locale=en\_EP&FT=D&date=19900623&CC=SU&NR=1259650A1&KC=A1.

Drug Cisplatin by Human Excision Nuclease. *Proc. Natl. Acad. Sci. USA*. Vol.91, No.22, pp. 10394-10398.

Jakupec, M.A., Galanski, M., Arion, V.B., Hartinger C.G., & Keppler, B.K. (2008). Antitumour Metal Compounds: More than Theme and Variations. *Dalton Trans.*, No.2, pp. 183–194.

402 Nitroxides – Theory, Experiment and Applications

Berlin.

 http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=8&ND=3& adjacent=true&locale=en\_EP&FT=D&date=19900623&CC=SU&NR=1259650A1&KC=A1. Emanuel, N.M., & Konovalova, N.P. (1992). Nitroxyl Radicals for Cancer Chemotherapy, In: *Bioactive Spin Labels*, Zhdanov, R.I. (Ed.). pp. 439–460, Springer, ISBN 3-54-53811-9,

Farrell, N., Qu, Y., Bierbach, U., Valsecchi, M., & Menta, E. (1999). Structure-Activity Relationships Within Di- and Trinuclear Platinum Phase-I Clinical Anticancer Agents, In: *Cisplatin: Chemistry and Biochemistry of a Leading AnticancerDrugs*, B. Lippert, (Ed.),

Frey, U., Ranford, J.D., & Sadler, P.J. (1993). Ring-opening Reactions of the Anticancer Drug Carboplatin: NMR Characterization of cis-[Pt(NH3)2(CBDCA-O)(5'-GMP-N7)] in

Gariboldi, M.B., Lucchi, S., Caserini, C., Supino, R., Oliva, C., & Monti, E. (1998). Antiproliferative Effect of the Piperidine Nitroxide Tempol on Neoplastic and Nonneoplastic Mammalian Cell Lines. *Free Rad. Biol. Med*., Vol.24, No.6, pp. 913–923. Gariboldi, M.B., Rimoldi, V., Supino, R., Favini, E., & Monti, E. (2000). The Nitroxide Tempol Induces Oxidative Stress, p21WAF1/CIP1, and Cell Death in HL60 Cells*. Free Rad. Biol.*

Gariboldi, M.B., Ravizza, R., Petterino, C., Castagnaro, M., Finocchiaro, G., & Monti, E. (2003). Study of *in vitro* and *in vivo* Effects of the Piperidine Nitroxide Tempol—a Potential New Therapeutic Agent for Gliomas. *Eur. J. Cancer*, Vol.39, No.6, pp. 829–837. Gariboldi, M.B., Terni, F., Ravizza, R., Meschini, S., Marra, M., Condello, M., Arancia, G., & Monti, E. (2006). The Nitroxide Tempol Modulates Anthracycline Resistance in Breast

Giandomenico, C.M., Abrams, M.J., Murrer, B.A., Vollano, J.F., Rheinheimer, M.I., Wyer, S.B., Bossard, G.E., Higgins, J. D. (1995). Carboxylation of Kinetically Inert Platinum(IV) Hydroxy Complexes. An Entrée into Orally Active Platinum(IV) Antitumor Agents.

Goldstein, S., Merenyi, G., Russo, A., & Samuni, A. (2003). The Role of Oxoammonium Cation in the SOD-Mimic Activity of Cyclic Nitroxides. *J. Am. Chem. Soc*. Vol.125, No.3,

Goldstein, S., Samuni, A., Hideg, K., & Merenyi, G. (2006). Structure-Activity Relationship of Cyclic Nitroxides as SOD Mimics and Scavengers of Nitrogen Dioxide and Carbonate

Gorczyca, W., Gong, J., Ardelt, B., Traganos, F., & Darzynkiewicz, Z. (1993). The Cell Cycle Related Differences in Susceptibility of HL-60 Cells to Apoptosis Induced by Various

Hambley T.W. (1997). The Influence of Structure on the Activity and Toxicity of Pt Anti-

Ho, Y.P., Au-Yeung, S.C., To, K.K. (2003). Platinum-based Anticancer Agents: Innovative Design Strategies and Biological Perspectives. *Med. Res. Rev*., Vol.23, No.5, pp. 633-655. Huang, J.C., Zamble, D.B., Reardon, J.T., Lippard, S.J., & Sancar, A. (1994). HMG-Domain Proteins Specifically Inhibit the Repair of the Major DNA Adduct of the Anticancer

pp. 479–496, Verlag Helvetica Chimica Acta, ISBN 3-906390-20-9, Zurich.

Solution. *Inorg. Chem.*, Vol.32, No.8, pp. 1333–1340.

Cancer Cells. *Free Rad. Biol. Med.,* Vol.40, No.8, pp. 1409–1418*.*

Radicals. *J. Phys. Chem. A.* Vol.110, No.10, pp. 3679-3685.

Antitumor Agents. *Cancer Res.*, Vol.53, No.13, pp. 3186–3192.

cancer Drugs. *Coord. Chem. Rev*., Vol.166, November 1997, pp. 181–223.

*Med.,* Vol.29, No.7, pp. 633–641*.*

*Inorg. Chem*., Vol.34, No.5, pp. 1015–1021.

pp. 789-795.

Sen', V.D., Shugalii, A.V., & Kulikov, A.V. (2002). DNA Modification by *cis*-Diaminoplatinum(II) Complexes with Aminonitroxide Ligands. *Russ. Chem. Bull.,*  Vol.51, No.6, pp. 11058–1064.

404 Nitroxides – Theory, Experiment and Applications

No.1, pp. 53-60.

2193.

pp. 343–348.

445-453.

Vol.305, No.3, pp. 1183-1190.

Vol.42, No.3, pp. 548–551.

Vol.47, No.8, pp. 1598–1602.

*Bull.*, Vol.25, No.8, pp. 1647–1654.

*Chem. Bull.*, Vol.38, No.9, pp. 1928–1931.

*Chim. Scand*., Vol.48, No.2, pp. 485-489.

Oksanen, M., & Leskela, M. (1994). Synthesis of Ammonium Trichloromonoammineplatinate(II) Improved through Control of Temperature. *Acta*

Oksanen, M. (1997). A Novel Characterization of the Structure of "Cossa's Salt" Kx(NH4)1 x[PtCl3(NH3)]·H2O by Crystallographic Comparison with the Stoichiometric Compounds K[PtCl3(NH3)]·H2O and NH4[PtCl3(NH3)]·H2O. *Inorg. Chim. Acta*., Vol.269,

Potucka, L., Houskova, J., Syslova, K., Hamtil, R., Kacer, P., & Cerveny, L. (2011). HPLC Method for the Determination of the Purity of K[Pt(NH3)Cl3], a Precursor of the Platinum Complexes with Cytostatic Activity. *Anal. Lett*. , Vol.44, No.10–12, pp. 2182-

Raikov, Z., Todorov, D., Ilarionova, M., Demirov, G., Tsanova, T., & Kafalieva, D. (1985). Synthesis and Study of Spin-Labeled Nitrosoureas. *Cancer Biochem. Biophys.*, Vol.7, No.2,

Reynolds, C.P. & Maurer, B.J. (2005). Evaluating Response to Antineoplastic Drug Combinations in Tissue Culture Models. *Methods Mol. Med.,*Vol.110, pp. 173–183. Roubalová, E., Kvardová, V., Hrstka, R., Borilová, S., Michalová, E., Dubská, L., Müller, P., Sova, P., & Vojtesek, B. (2010). The Effect of Cellular Environment and p53 Status on the Mode of Action of the Platinum Derivative LA-12. *Invest. New Drugs*, Vol.28, No.4, pp.

Satoh, M., Kashihara, N., Fujimoto, S., Horike, H., Tokura, T., Namikoshi, T., Sasaki, T., & Makino, H. (2003). A Novel Free Radical Scavenger, Edarabone, Protects Against Cisplatin-induced Acute Renal Damage in vitro and in vivo. *J. Pharmacol. Exp*. *Ther.*,

Sen', V.D., Golubev, V.A., Kulyk, I.V., & Rozantsev, E.G. (1976). Mechanism of Reaction of Hydrogen Peroxide with Oxopiperidine Salts and Piperidinoxyl Radicals. *Russ. Chem.*

Sen', V.D., Golubev, V.A., & Bogdanov, G.N. (1989a). Nitroxylcarbamoyl Derivatives of 5-

Sen', V.D., (1989b). Synthesis of 3,4-Diamino-2,2,6,6-tetramethylpiperidine-1-oxyl, *Russ.*

Sen', V.D., (1993). Synthesis of Nitroxide Derivatives of Alkylnitrosourea, *Russ. Chem. Bull.*,

Sen', V.D., Golubev, V.A., Volkova, L.M., & Konovalova, N. P. (1996). Synthesis and Antitumor Activity of Platinum(II) Complexes with *trans*-3,4-Diamino-2,2,6,6-

Sen', V.D., Kulikov, A.V., Shugalii, A.V., & Konovalova, N.P. (1998). Synthesis of Dinitroxyl cis-Diaminoplatinum(II) Complexes and their Interaction with DNA. *Russ. Chem. Bull.*,

Sen', V.D., Rukina, N.A., Tkachev, V.V., Pis'menskii, A.V., Volkova, L.M., Goncharova, S.A., Raevskaya, T.A., Tikhomirov, A.G., Gorbacheva, L.B., & Konovalova, N.P. (2000). Synthesis, Structure, and Biological Activity of Mixed-ligand Platinum(II) Complexes

tetramethylpiperidine-1-oxyl. *J. Inorg. Biochem.*, Vol.64, No.1, pp. 69–77.

with Aminonitroxides. *Russ. Chem. Bull.,* Vol.49, No.9, pp. 1613–1619.

Fluorouracyl, *Russ. Chem. Bull.*, Vol.38, No.10, pp. 2132–2135.

**Chapter 15**


*1.3.1 Sourcing and distribution of water*

The central question was to establish how water is sourced and distributed in Africa. Different countries use different methods to facilitate water access to the community. Although the categorization of water sources usually takes the form of rural–urban community dichotomy, the sources could also be categorized as natural and artificial/conventional dichotomy. There are mainly two sources of community water supply in Africa, Artificial/Conventional and Natural. Whereas artificial sources include pipes, bore holes, wells and dams, Natural sources include rain, rivers/streams, and ponds. The uniqueness lies in the management of the distribution of the water from the sources to the consumers and the actors involved in the process. The extent to which a large population depends on natural sources is a manifestation of low level intervention of the government, thereby leaving the population to depend on nature. Whereas the natural sources are free, the water quality is unsafe and depends on climate variability. The use of conventional sources, whether fixed point or mobile vendors require investments in pipe, treatment and other means of distribution and abstraction permits for Water service providers (WSPs).

Each of the five countries, in different proportions, has both natural and artificial sources of community water supply. In Kenya, community water projects have been recognized as alternative water Service Providers (WSP) and are registered by Water Services Regulatory Board (WASREB) after meeting the conditions set by the regulator. The community water supplies are mainly through Individual bore holes, shallow wells, and water connection (kiosks) main utility companies [12]. Whereas some households have shallow wells in their yards, which neighbors are able to access free of charge, others rely on a single tap from which they sell water by the jerry can. In Dar es Salam, Tanzania, some entrepreneurs have constructed small-scale piped networks, supplying water kiosks (canteens) without a piped connection and sell water from Dar es Salaam Water and Sanitation Company (DAWASCO) even in areas that are beyond the reach of the utility's piped network. The Mobile Vendors include water tankers and trucks; pushcart and bicycle vendors who buy from a variety of water sources and resell to households. Another system is where DAWASCO supplies water to a community water public taps, managed by a Water Committee elected by the community for a three-year term [13].

Water shortages in the city of Dar es Salaam, Tanzania, had forced the community to seek for alternative ways of having clean and safe water. In other words, inadequacy in the quality and quantity of water for each of its intended purposes creates need for a communal approach as a coping response. The sources to

**61**

projects [15].

*Community Management and Water Service Delivery in Africa*

community approach to address the unmet needs. Even in cases where the government initiated water projects for the community, the management and sustainability of the project is left at the hands of the community. More often than not, citizens cannot access water without private efforts e.g. by installing water pumps or by colluding with water utility staff, or by tapping into informal networks of neighbors, water vendors and other intermediaries. Setting up a functional community water project takes high costs, a long time, complex processes of mobilizing

Citizens increasingly lose hope and trust towards the government if they have to pay a high transaction costs in terms of time, money and other resources to access official improved drinking-water sources, hence encourage either the proliferation of informal water providers as alternatives or corruption within official providers [14]. Poor communities therefore either resort to buying water from water vendors, water kiosks, and other unapproved sources which inflate their household expenditure. Whereas in settlements with piped water close by, residents walk to fetch water or pay for people to cart water to their residence, where they are far from piped water supply, residents contract small-scale suppliers who deliver water in motorized tanks. To help alleviate the deficit, the government of Ghana encourages the communities to provide services for themselves in the form of self-help

Like in Kenya, Ghana, Tanzania and Malawi, Nigeria's main sources of community water supplies, are both natural including rain water, rivers, stream and conventional ones which include public tap, borehole, hand dug well, neighbors and Water vendors formal or informal [16]. Daily water supplies either come from the natural sources or modern/conventional supply sources. While relatively over 80% of the rural population depend on the natural sources of supplies, the urban residents are mostly served with supplies whose regularity vary depending on residential areas and other socio-economic characteristics, mostly related with ability to pay as well as the relative influence of certain individuals and groups [17]. Unlike in Kenya and Tanzania, formal water vending in Nigeria is undertaken by formal bodies, such as water utilities themselves or registered associations, or by small scale informal supplies in tankers and the water is obtained either from treated utility supplies or from registered sources. Like in Kenya and Tanzania, informal vendors in Nigeria obtain water from many different sources, protected and unprotected and deliver small quantities of water for domestic use in a variety of ways ranging from carts and cycles to containers or wheel barrows, trolleys and animal-drawn or mechanized carts and tanker trucks [18]. The government does

very little to guarantee safety of the sources of community water.

adequate and safe water supply to most urban centres in Nigeria [16].

In all the countries, the government has acknowledged community water supply sources, irrespective of their safety and quality. In Ghana and Malawi, the government contributes heavily for the establishment of conventional sources. In Tanzania, the government has accommodated community identified sources. In Kenya, the choice of sources to establish is the prerogatives of each community. The fact that natural sources, most of which are unsafe, still form a large portion of

Notwithstanding its intervention, Community water supply in Nigeria is still uncoordinated, mainly done by individuals to address the unmet needs by the government supplied water to the community. Unlike in Kenya, the registered associations do not necessarily supply water to the defined membership but to the market implying that those who cannot afford are still at risk of going without water. In the face of absolute neglect by the government with respect to water provision, water vendors come in as an intervention. Although source is defined as unsafe, it is unlikely that in the immediate future the government will succeed in providing

citizens, government authorities, NGOs, and many other stakeholders.

*DOI: http://dx.doi.org/10.5772/intechopen.90746*

### *Community Management and Water Service Delivery in Africa DOI: http://dx.doi.org/10.5772/intechopen.90746*

*Resources of Water*

African counties.

partnerships.

providers (WSPs).

**1.3 Results and discussion**

*1.3.1 Sourcing and distribution of water*

of the interactions of the actors involved in community water management systems in each country ranging from source to distribution. Of particular importance was the role of the government in each of the activities and how that impacted on water access to the consumers and with what results. The fundamental question was whether or not community management improved water service delivery in the five

We have discussed in this section, the dynamics of community water management in the five counties namely, Kenya, Tanzania, Malawi, Ghana and Nigeria by evaluating four processes of: sourcing and distribution of water; the role of government; the community membership; and the involvement of public private

The central question was to establish how water is sourced and distributed in Africa. Different countries use different methods to facilitate water access to the community. Although the categorization of water sources usually takes the form of rural–urban community dichotomy, the sources could also be categorized as natural and artificial/conventional dichotomy. There are mainly two sources of community water supply in Africa, Artificial/Conventional and Natural. Whereas artificial sources include pipes, bore holes, wells and dams, Natural sources include rain, rivers/streams, and ponds. The uniqueness lies in the management of the distribution of the water from the sources to the consumers and the actors involved in the process. The extent to which a large population depends on natural sources is a manifestation of low level intervention of the government, thereby leaving the population to depend on nature. Whereas the natural sources are free, the water quality is unsafe and depends on climate variability. The use of conventional sources, whether fixed point or mobile vendors require investments in pipe, treatment and other means of distribution and abstraction permits for Water service

Each of the five countries, in different proportions, has both natural and artificial sources of community water supply. In Kenya, community water projects have been recognized as alternative water Service Providers (WSP) and are registered by Water Services Regulatory Board (WASREB) after meeting the conditions set by the regulator. The community water supplies are mainly through Individual bore holes, shallow wells, and water connection (kiosks) main utility companies [12]. Whereas some households have shallow wells in their yards, which neighbors are able to access free of charge, others rely on a single tap from which they sell water by the jerry can. In Dar es Salam, Tanzania, some entrepreneurs have constructed small-scale piped networks, supplying water kiosks (canteens) without a piped connection and sell water from Dar es Salaam Water and Sanitation Company (DAWASCO) even in areas that are beyond the reach of the utility's piped network. The Mobile Vendors include water tankers and trucks; pushcart and bicycle vendors who buy from a variety of water sources and resell to households. Another system is where DAWASCO supplies water to a community water public taps, managed by a

Water Committee elected by the community for a three-year term [13].

Water shortages in the city of Dar es Salaam, Tanzania, had forced the community to seek for alternative ways of having clean and safe water. In other words, inadequacy in the quality and quantity of water for each of its intended purposes creates need for a communal approach as a coping response. The sources to

**60**

community approach to address the unmet needs. Even in cases where the government initiated water projects for the community, the management and sustainability of the project is left at the hands of the community. More often than not, citizens cannot access water without private efforts e.g. by installing water pumps or by colluding with water utility staff, or by tapping into informal networks of neighbors, water vendors and other intermediaries. Setting up a functional community water project takes high costs, a long time, complex processes of mobilizing citizens, government authorities, NGOs, and many other stakeholders.

Citizens increasingly lose hope and trust towards the government if they have to pay a high transaction costs in terms of time, money and other resources to access official improved drinking-water sources, hence encourage either the proliferation of informal water providers as alternatives or corruption within official providers [14]. Poor communities therefore either resort to buying water from water vendors, water kiosks, and other unapproved sources which inflate their household expenditure. Whereas in settlements with piped water close by, residents walk to fetch water or pay for people to cart water to their residence, where they are far from piped water supply, residents contract small-scale suppliers who deliver water in motorized tanks. To help alleviate the deficit, the government of Ghana encourages the communities to provide services for themselves in the form of self-help projects [15].

Like in Kenya, Ghana, Tanzania and Malawi, Nigeria's main sources of community water supplies, are both natural including rain water, rivers, stream and conventional ones which include public tap, borehole, hand dug well, neighbors and Water vendors formal or informal [16]. Daily water supplies either come from the natural sources or modern/conventional supply sources. While relatively over 80% of the rural population depend on the natural sources of supplies, the urban residents are mostly served with supplies whose regularity vary depending on residential areas and other socio-economic characteristics, mostly related with ability to pay as well as the relative influence of certain individuals and groups [17]. Unlike in Kenya and Tanzania, formal water vending in Nigeria is undertaken by formal bodies, such as water utilities themselves or registered associations, or by small scale informal supplies in tankers and the water is obtained either from treated utility supplies or from registered sources. Like in Kenya and Tanzania, informal vendors in Nigeria obtain water from many different sources, protected and unprotected and deliver small quantities of water for domestic use in a variety of ways ranging from carts and cycles to containers or wheel barrows, trolleys and animal-drawn or mechanized carts and tanker trucks [18]. The government does very little to guarantee safety of the sources of community water.

Notwithstanding its intervention, Community water supply in Nigeria is still uncoordinated, mainly done by individuals to address the unmet needs by the government supplied water to the community. Unlike in Kenya, the registered associations do not necessarily supply water to the defined membership but to the market implying that those who cannot afford are still at risk of going without water. In the face of absolute neglect by the government with respect to water provision, water vendors come in as an intervention. Although source is defined as unsafe, it is unlikely that in the immediate future the government will succeed in providing adequate and safe water supply to most urban centres in Nigeria [16].

In all the countries, the government has acknowledged community water supply sources, irrespective of their safety and quality. In Ghana and Malawi, the government contributes heavily for the establishment of conventional sources. In Tanzania, the government has accommodated community identified sources. In Kenya, the choice of sources to establish is the prerogatives of each community. The fact that natural sources, most of which are unsafe, still form a large portion of the community water source, is an indication of the African governments' lethargy towards providing quality water to its citizens. The use of different sources of community water is therefore a coping mechanism to mitigate the failures of the governments to provide adequate water.


**1. Introduction**

The basic purpose of the green chemistry is to diminish waste generation by complete consumption of material in the processes, or eliminate the generation and avoiding the processes that hazardous waste for human health [1]. Industrial and academic researchers are now more focusing on 'green' polymers from nature, instead of polymers derived from petroleum because of their sustainable environment-friendly nature, easy biodegradability and less energy need for renewing [2]. Fibers having diameters ~100 nm or lower exhibit special features are called nanofibers. These fibers have unique high surface area with respect to the mass compared to conventional fibers. They have high surface area ~ 1000 m2 /g, high porosity, tight pores and low density. These features of materials are desirable for their application in different fields [2]. Some fields in which polymeric, ceramic and composite nanofibers are used include healthcare industry, biotechnological applications, environmental engineering, defense, security and energy storage. Researchers are interest to synthesize nanomaterials with special physical and chemical features for their application in the above mentioned fields. The extensive improvement has been recorded in the area of nanoparticles, nanotubes, nanofibers, nanolayers, nanodevices and nano-structured biological materials.

Providing clean drinking to public and improving their general health status is an important field of research and application of nanomaterials. Nanomaterials adsorb metals from the water on their surface and detoxify it [3]. The nanomaterials with large surface area naturally have high sorption capacities and less disposable waste generation. In nanostructures more unsaturated surface atoms get exposed, proximal functional groups enhance reactivity and show nanoscale effect with decrease in particle size <20 nm diameter. A nanoparticle can have high adsorption for a selected metal [3]. Oxides of aluminum, iron, manganese and titanium have been investigated for their potential heavy metal adsorption from water. Titanium dioxide (TiO2) anatase has been applied in many industries. Bulks as well as nanoparticles of Titanium dioxide (Titanium dioxide (TiO2)) were able to degrade and remove organic compounds in presence of UV light and redox reactions in water [3].

The suitability of the sorbent for treating an inorganic pollutant depends on the cost effectivity and technical applicability. It is always necessary to develop an efficient and cheap adsorbent for the removing heavy metals from the industrial effluents, especially in the economically weak developing countries. Polymeric ceramic nanofibers are good option in this regard. For unit mass ceramic nanofibers harbor extraordinary high surface area and porosity. These low cost fiber show excellent structural and mechanical properties like high axial strength and extreme flexibility for a low basis weight [4].

Iijima (1991) discovered carbon nanotubes (CNTs) having excellent properties and applications. Depending upon layers of carbon atom in the wall, the tubular sheets of graphite are called single-walled CNT or multi-walled CNT [4]. Many heavy metals (Cr, Cu, Cd, Ni and Pb,) have been removed from waste water using CNTs [4]. The actual mechanisms by which metal ions get adsorbed onto CNTs is little bit complicated, however, possible it involves electrostatic attractive forces, sorption-precipitation or other chemical interaction between the metal ions and functional groups on the CNT surface.

The polymers applications are generally limited due to their poor mechanical strength and low antimicrobial resistance. A modification of polymers rectifies the limitations and improves wound healing property. A prominent biopolymer polylactide (PLA) has been exploited immensely in biomedical field due to biodegradability and biocompatibility [5]. Scaffolds of PLA temporary provide structural support to cells and tissue during healing by modulating cellular response that is helpful tissue engineering [6]. Wounds, cuts and damages skin heal rapidly in absence of germ because microbes on such surface trigger the immune response of our body and inflammation damage tissue leading to compromised self-healing. If such polymer scaffolds could contain antimicrobial agents capable to prevent opportunistic microbe on the wound surface, the healing process could be accelerated. When silver nanoparticles (AgNPs) impregnated into the polymer matrix, they impressive impart antimicrobial activity to scaffold in addition to improving mechanical, chemical, catalytic activity. Biomedically Ag-NPs have been applied in wound dressing material and in diagnosis of cancer [7] and sutures [8]. In addition to the antimicrobial activity, non-toxicity AgNPs are utilized in the fabricating non-infectious scaffolds. AgNPs are synthesized by using reducing chemical agents such as sodium borohydride [9], hydrazine etc. However, they have been extensively synthesized by use of medicinally important plant extracts [10]. The colloidal AgNPs has been synthesized using extracts of *Cocciniaindica* [11], *Carica papaya* [12], *Brassica rapa* [13], *Aloe vera* [14], *Melia dubia* [15], *Citrus* sp. [16], *Acalyphaindica* [17], *Prunusamygdalus* [18]*.*

It is the cationic property that gives Chitosan (CHT) the ability to penetrate mucous layers in biomedical applications, perform an antimicrobial function in food preservatives, and trap dyes and metals in waste water [19]. It is also being used in technical applications such as packaging and decontamination, because of its physico-chemical properties, such as hydrophobicity, thermal stability, and mechanical performances [20]. These properties, unique to CHT, combined with high porosity and surface area by its nanosize, render it important for a range of different functional systems.

**21**

covered in details.

**Figure 1.**

*process.*

**2.1 Template synthesis**

*Green Synthesis of Nanofiber and Its Affecting Parameters*

Hard and inert ceramic materials have excellent mechanical and thermal properties, in addition to superb chemical and corrosion resistance. These characteristics make them suitable for being used in electrodes, photonic devices, electronic and sensors, catalyst supports, drug delivery system and environmental science. The nanoribbons, nanorods, nanotubes, nanowires nanowhiskers and nanofibers are important nanostructures that are predominantly being synthesized in field of nanotechnology. These one-dimensional ceramics are interesting due to their unique optical, thermal, electrical, magnetic, gas sensing and or catalytic property. Such property of nanomaterial develop due to specific surface morphology and very small dimension compared to the same material in bulk. Among these nanostructures, highly porous, low density and high surface area containing nanofibers have been potentially applied in various fields [21]. A scanning electron micrograph of

*Scanning electron micrograph of composite nanofibers synthesized from the PVP polymer by electrospinning*

composite copper ceria nanofiber synthesized is given below in **Figure 1**.

A number of methods have been used for fabricating nanofibers. Some of them are template synthesis [22], self-assembly [23, 24], phase separation [23], melt-blown [25] and electrospinning [26, 27]. Each process has its own challenge in preparing nanofibers. Selection of process for producing nanofibers depends on materials, fibers alignment, production rate and most importantly investment cost. Some of them are discussed below and only electrospinning process has been

The method employs a template or mold of desired material and structure is used to synthesize nanofibers. Generally, a templet of metal oxide membrane of nanodimension pores is allowed to pass the polymer solution through it by applying water pressure from one side. The nanofibers extrude from the other side of the membrane. The generated fiber comes in contact with solidifying solution. Small sized nanofibers few micrometers length are generated. The fiber diameter is determined by the membrane pore size [28, 29]. The technique is very advantageous in fabricat-

ing nanofibers of various diameter by changing templates membrane.

**2. Preparation methods of nanofibres**

*DOI: http://dx.doi.org/10.5772/intechopen.94539*

#### **Figure 1.**

*Nanofibers - Synthesis, Properties and Applications*

flexibility for a low basis weight [4].

functional groups on the CNT surface.

*Acalyphaindica* [17], *Prunusamygdalus* [18]*.*

different functional systems.

functional groups enhance reactivity and show nanoscale effect with decrease in particle size <20 nm diameter. A nanoparticle can have high adsorption for a selected metal [3]. Oxides of aluminum, iron, manganese and titanium have been investigated for their potential heavy metal adsorption from water. Titanium dioxide (TiO2) anatase has been applied in many industries. Bulks as well as nanoparticles of Titanium dioxide (Titanium dioxide (TiO2)) were able to degrade and remove organic compounds in presence of UV light and redox reactions in water [3].

The suitability of the sorbent for treating an inorganic pollutant depends on the cost effectivity and technical applicability. It is always necessary to develop an efficient and cheap adsorbent for the removing heavy metals from the industrial effluents, especially in the economically weak developing countries. Polymeric ceramic nanofibers are good option in this regard. For unit mass ceramic nanofibers harbor extraordinary high surface area and porosity. These low cost fiber show excellent structural and mechanical properties like high axial strength and extreme

Iijima (1991) discovered carbon nanotubes (CNTs) having excellent properties and applications. Depending upon layers of carbon atom in the wall, the tubular sheets of graphite are called single-walled CNT or multi-walled CNT [4]. Many heavy metals (Cr, Cu, Cd, Ni and Pb,) have been removed from waste water using CNTs [4]. The actual mechanisms by which metal ions get adsorbed onto CNTs is little bit complicated, however, possible it involves electrostatic attractive forces, sorption-precipitation or other chemical interaction between the metal ions and

The polymers applications are generally limited due to their poor mechanical strength and low antimicrobial resistance. A modification of polymers rectifies the limitations and improves wound healing property. A prominent biopolymer polylactide (PLA) has been exploited immensely in biomedical field due to biodegradability and biocompatibility [5]. Scaffolds of PLA temporary provide structural support to cells and tissue during healing by modulating cellular response that is helpful tissue engineering [6]. Wounds, cuts and damages skin heal rapidly in absence of germ because microbes on such surface trigger the immune response of our body and inflammation damage tissue leading to compromised self-healing. If such polymer scaffolds could contain antimicrobial agents capable to prevent opportunistic microbe on the wound surface, the healing process could be accelerated. When silver nanoparticles (AgNPs) impregnated into the polymer matrix, they impressive impart antimicrobial activity to scaffold in addition to improving mechanical, chemical, catalytic activity. Biomedically Ag-NPs have been applied in wound dressing material and in diagnosis of cancer [7] and sutures [8]. In addition to the antimicrobial activity, non-toxicity AgNPs are utilized in the fabricating non-infectious scaffolds. AgNPs are synthesized by using reducing chemical agents such as sodium borohydride [9], hydrazine etc. However, they have been extensively synthesized by use of medicinally important plant extracts [10]. The colloidal AgNPs has been synthesized using extracts of *Cocciniaindica* [11], *Carica papaya* [12], *Brassica rapa* [13], *Aloe vera* [14], *Melia dubia* [15], *Citrus* sp. [16],

It is the cationic property that gives Chitosan (CHT) the ability to penetrate mucous layers in biomedical applications, perform an antimicrobial function in food preservatives, and trap dyes and metals in waste water [19]. It is also being used in technical applications such as packaging and decontamination, because of its physico-chemical properties, such as hydrophobicity, thermal stability, and mechanical performances [20]. These properties, unique to CHT, combined with high porosity and surface area by its nanosize, render it important for a range of

**20**

*Scanning electron micrograph of composite nanofibers synthesized from the PVP polymer by electrospinning process.*

Hard and inert ceramic materials have excellent mechanical and thermal properties, in addition to superb chemical and corrosion resistance. These characteristics make them suitable for being used in electrodes, photonic devices, electronic and sensors, catalyst supports, drug delivery system and environmental science. The nanoribbons, nanorods, nanotubes, nanowires nanowhiskers and nanofibers are important nanostructures that are predominantly being synthesized in field of nanotechnology. These one-dimensional ceramics are interesting due to their unique optical, thermal, electrical, magnetic, gas sensing and or catalytic property. Such property of nanomaterial develop due to specific surface morphology and very small dimension compared to the same material in bulk. Among these nanostructures, highly porous, low density and high surface area containing nanofibers have been potentially applied in various fields [21]. A scanning electron micrograph of composite copper ceria nanofiber synthesized is given below in **Figure 1**.