*Katherine K.M. Stavropoulos, Education and Human Development Series Editor*

Published in London, UK © 2023 IntechOpen

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Higher Education - Reflections From the Field - Volume 4

IntechOpen Series

Education and Human Development, Volume 6

Higher Education

Reflections From the Field - Volume 4

*Edited by Lee Waller and Sharon Kay Waller*


*4.5. Light-Responsive Delivery System*

The surface of MSN can be decorated introducing photo-cleavable linkers for triggering the cargo release from MSN, by applying lights with di fferent wavelengths (ultraviolet, visible or near-infrared) [187,188]. Among all, as ultraviolet (UV) radiation has the highest power to easily break the bond, it has been the most commonly used light stimulus for the controlled drug release from MSN [187]. It has been reported that MSN coated with photo-responsive azobenzene-modified nucleic acid can trigger the drug release under UV light radiation [189]. However, the biomedical application of the UV light becomes restricted due to its toxicity and low tissue penetrability [190,191]. As an alternate, visible (Vis) light can be employed, as it is less harmful and has a higher tissue penetrability. Few Vis light-triggered MSN drug delivery systems have been reported [192,193]. For example, light responsive porphyrin nanocaps have been used to decorate the MSN. Porphyrin nanocaps are anchored via reactive oxygen species (ROS)-cleavable linkages, so that in response to the Vis light singlet oxygen molecules will be generated to break the sensitive linker and trigger the drug release by opening the pore of MSN [193].

Even though there are several advantages of using light (such as its easy application, non-invasiveness, low toxicity and precise focalization in the desired place), light-responsive delivery is restricted by its low tissue penetration capability (only a few millimeters). It has been observed that the best wavelengths for satisfactory tissue penetration are within the biological spectra, typically 800–1100 nm [134]. Likewise, Guardado-Alvarez et al. have exploited photolabile coumarine-molecules in the capping moiety of MSN surface to control the cargo release upon two-photon excitation at 800 nm [194]. Furthermore, Croissant and colleagues have shown that they can control drug release via a photo-transducer from mesoporous silica nanoimpellers in human cancer cells using two-photon light [195].


**11. Making the ECV easier**

The procedures that have proved their usefulness in randomized studies are only the tocolytics aiming at relaxing the uterus at the version.

In a 2005 *Cochrane*'s review, tocolytics were related to a reduction of the failure risk in external cephalic version both with nulliparous and multiparous women, as well as to a reduction in the caesarean rate. In the "tocolytic groups" the achievement of the external cephalic version in a minute and the fetal bradycardia was less common. These results are valid for tocolytics such as ritodrine, salbutamol and terbutaline (both by an intravenous or subcutaneous injection). However, no evidence has been proved in order to use other tocolytics suggested in other projects (such as the intravenous nitroglycerin, sublingual glyceryl trinitrate or nifidipine). Thus, pregnant women should be warned about the tocolytics adverse effects (evidence level Ia and recommendation level A).

In the same revision it was concluded that despite the fact that many multiple studies have been carried out, there is not enough scientific evidence proving the use of epidural analgesia, vibroacoustic stimulation or amnioinfusion in order to facilitate the version.

A small prospective study published in 2010 concluded that the factors increasing the probability of success and reducing the rate of adverse effects in ECV are a single attempt at the maneuver, total duration of the maneuver of less than 5minutes, and use of salbutamol as a uterine relaxant (Delgado et al, 2010). use a

There were contradictory results regarding the outcomes using the epidural or spinal analgesia to facilitate the version maneuvers. Therefore, the use of regional analgesia in order to facilitate the external cephalic version cannot be recommended.

In the case of the acoustic stimulation of the fetus, there is a small project which proved a significant reduction in the external cephalic version failure rate in midline fetal spine positions. Nevertheless, as this project is small, the confirmation of the results by other projects is necessary before including this procedure into the clinical practice.

No randomized clinical studies on the amnioinfusion practices as a method to facilitate the external version were found.


**4. Prospects for use of sisal fibre in automotive manufacturing**

Sisal fibres can be utilized in Door boards, Lodge linings; Brake liners; thermo acoustic protection, trim parts, seat pads and back etc. The potential partners for the utility of sisal fibre in auto-segment industry are as follows: Mercedes Benz, Freightliner, Daimler Chrysler, Chevrolet, and General Motors, Mahindra and Mahindra, Tata Motors and Hero Honda and so on. The money-saving advantage investigation, techno-business attainability and the difficulties for sisal fibre double-dealing for different designing applications are as per the following: sisal is xerophytes and fills in badlands, which moderates soil and procures carbon credits. Assured maintainable fibre creation is 2.5 ton/ha for 6–8 years. Surface medicines empower sisal fibres to be utilized as support in a polymer lattice and it has advantageous over mineral and other ordinary regular fibres [10–12].


**4. Nano-sensing technology**

#### **4.1 Nanoparticle tracking analysis (NTA)**

Nanoparticle tracking analysis (NTA) is well acknowledged and commercially available technique for EV characterization. By tracking the Brownian motion of each particle, the hydrodynamic diameter of each particle is calculated with Stockes-Einstein equation. Thereafter, size distribution and concentration of EVs in a fluid sample could be obtained. Combined with fluorescent labeled antibodies or molecular beacons, EV subpopulation with expression of certain protein or miRNAs, respectively, could be quantified (**Figure 8**).

As a modified tracking analysis of EVs, an on-chip microcapillary electrophoresis system was built with a laser dark-field microscope. The tracking analysis of the electrophoretic migration of individual exosomes were performed and the zeta potential distribution of exosomes were able to be analyzed. The system consists of a chip, a pair of platinum electrodes, a DC power supply, a laser source, an inverted microscope, and an EMCCD camera (**Figure 9**) [22].

**Figure 8.**

*The principle of nanoparticle tracking analysis (NTA) and its obtained EV size distribution.*

**Figure 9.** *Tracking analysis combined with zeta potential measurement of single EVs.*

### **4.2 Fluorescence correlation spectroscopy (FCS)**

Fluorescence Correlation Spectroscopy (FCS) were set up for characterize the GFP labeled vesicles at the single molecule – single vesicle level. FCS detects temporal fluorescence fluctuations in a defined confocal volume at a single photon sensitivity [23].

#### **4.3 Surface plasmon resonance (SPR)**

Surface plasmon resonance (SPR) detects real-time interactions between the receptors and the targeted biomolecules. SPR sensors show high sensitivity for labelfree exosome quantification, which could be attributed to a nanoscale sensing range closing to exosome size. The receptors were immobilized on the surface of the biosensor. When a solution of biomolecules flows across, the targeted biomolecules interact with the receptors to change the refractive index of the sensor surface. The response of the sensor is measured in resonance units (RU) and is proportional to the mass of molecules interacting with the immobilized receptor. (**Figure 10**) Nano-plasmonic exosome (nPLEX) system was developed based on SPR principles and utilized 200 nm plasmonic nanoholes for EV capture and detection. nPLEX enables quantitative detection and proteomic profiling of EVs at the throughput of 12 biomarkers

*High-Throughput Single Extracellular Vesicle Profiling DOI: http://dx.doi.org/10.5772/intechopen.97544*

#### **Figure 10.**

*The priciple of surface plasmon resonance (SPR).*

detection with antibodies immobilized at 12 channels of a microfluidic chip [24]. The nPLEX-FL assay enables multiplexed single EV analysis of targeted markers with improved sensitivities. In nPLEX-FL assay, EVs are biotinylated and then captured on the nanohole surface with avidin coating. EVs are immunostained by fluorescent labeled antibodies. Plasmon-enhanced fluorescence detection can amplify fluorescence signals using plasmonic metallic nanostructures. The labeled EVs are imaged, and their fluorescent intensities are analyzed. Therefore, biomarker distribution analysis could be performed on a single-EV level [25]. A localized surface plasmon resonance imaging (LSPRi) platform improves the limit of detection down to the single exosome limit. With a 400 nanopillar array sensor chip, single EVs are captured by nanopillar for both imaging and spectrometer measurement (**Figure 11**) [26].

### **4.4 Raman spectroscopy**

Raman spectroscopy is a spectral analysis method that determines the chemical properties of samples by measuring the vibration mode of covalent bonds caused by a radiation laser. Raman spectroscopy is non-destructive label-free analysis and therefore is suitable for analysis of biological samples. Laser tweezers Raman spectroscopy (LTRS)explore the chemical content of individual EVs, in which a tightly focused laser beam traps small particles at the laser's focal point. A confocal detection of Raman scattering from the precise focal volume allows EVs to be studied individually. Based on the exosomal chemical differences, EVs could be classified into subpopulations (**Figure 12**) [27–29].

#### **Figure 11.**

*A localized surface plasmon resonance imaging (LSPRi) nanopillar platform enables both spectrum and image readout.*

**Figure 12.**

*The principle of laser tweezers Raman spectroscopy (LTRS).*

**Figure 13.** *Multi modal characterization of antibody captured individual EVs via SEM, AFM and Raman spectroscopy.*

Surface-enhanced Raman spectroscopy (SERS) is a type of molecular vibration spectrum with enhanced Raman scattering signals from molecules adsorbed on noble metal (Ag, Au) nanostructures. SERS has been applied for the detection of cancer exosomes due to its high sensitivity, specificity, and multiplexing capability. Single EV analysis was performed in several studies. An graphene-coated periodic goldpyramid were used as SERS substrate to detect single EVs and EV samples from different biological sources were distinguished in their Raman signature [30]. In another study, gold nanoparticles (AuNP) coated single EVs were formed due to electrostatic interaction between cationic AuNP and anionic EV membrane. SERS spectra of individual ELVs with a high density of AuNP were then acquired and variations in the SERS spectra of individual ELVs could be used for EV heterogeneity analysis [31]. Multi modal characterization of individual EVs could be achieved after EV capture on antibody functionalized stainless steel substrate followed by characterization via SEM, AFM and Raman spectroscopy (**Figure 13**) [32].