1 . 0 . 25 g high molecule weight sodium hyaluronate powder ( hha ; mw : 2 mda ; freda ) and 0 . 25 g low molecule weight sodium hyaluronate powder ( lha ; mw : 0 . 35 mda ; freda ) were added into 50 ml pbs buffer ( phosphate buffered saline ) respectively to form 0 . 5 % solution , and then stirred for 6 hours until the powder was totally dissolved . 2 . 0 . 05 g lha powder and 0 . 2 g hha powder ( ratio 2 : 8 ; medium molecular weight sodium hyaluronate powder , mha ) were added into 50 ml pbs buffer , and then stirred for 6 hours until the powder was totally dissolved . 3 . mobile phase solution of gpc ( gel permeation chromatography ) system was prepared by : ( 1 ) adding 35 . 49 g na 2 hpo 4 powder into 450 ml deionized distilled water ( dd water ) and stirred for 30 minutes in room temperature to form 0 . 5 m na 2 hpo 4 solution ; and ( 2 ) adding 18 g nah 2 po 4 powder into 250 ml dd water and stirred for 30 minutes in room temperature to form 0 . 5 m nah 2 po 4 solution . 4 . 1 u / ml haase was prepared by dissolving haase powder into pbs buffer in 4 ° c . 5 . 2 ml ha sample , 1 ml 10 u / ml haase and 7 ml pbs buffer were mixed for 3 minutes by vortex in 15 ml glass tube . 6 . the tube was shaken by 50 rpm in water bath . 1 ml solution was taken after the 15 , 30 , 45 , 60 , 75 , 90 , 105 , 120 minutes and then supplied with 1 ml haase each time . every 1 ml solution was filtered through 0 . 45 μm filter . 20 μl solution was injected into gpc system and then the diagram was recorded . 7 . the situation of gpc system were ( 1 ) column : 2 × gmpwx1 ( tsk - gel ); ( 2 ) mobile phase flow rate : 1 ml / min ; ( 3 ) temperature : 30 . 8 . all values in the table were expressed as means of n observations . the histological index was analyzed by student &# 39 ; s t - test . fig2 shows the retention time of has by gpc diagram . the vertical axis represents the retention time in gpc , the horizontal axis represents the degradation time of ha in solution containing haase . the horizontal dotted lines from up to down represent the retention time of 2 mda , 1 mda , 350 kda and 17 kda has , respectively . the retention time was obviously increased followed with the increased degradation of all three has . after 15 minutes of degradation , the average mw of hha and mha were degraded to about 1 mda . after 37 minutes of degradation , the average mw of hha and mha were degraded to about 350 kda . after 90 minutes of degradation , the average molecular weights of hha , mha and lha were degraded such that no obvious difference exists among the average molecular weights , which were all larger than 17 kda . 1 . lha , mha and hha were prepared as the same as example 1 . 2 . mobile phase solution of gpc system was prepared as the same as example 1 . 3 . artificial gastric juice ( 0 . 1 n hcl ) was prepared by mixing 5 . 72 ml 17 . 5 n hcl and 90 ml dd water and stirred for 10 minutes as a stocking solution . 4 . 2 ml of hha , mha and lha were mixed with 8 ml artificial gastric juice , respectively in a 15 ml glass tube and by vortex for 3 minutes . 5 . the tube was shaken by 50 rpm in 37 ° c . water bath . 1 ml solution was taken after the 6 , 12 , 24 , 48 hours and then supplied with 1 ml artificial gastric juice each time . every 1 ml solution was filtered through 0 . 45 μm filter . 20 μl solution was injected into gpc system and then the diagram was recorded . 6 . all values in the table were expressed as means of n observations . the histological index was analyzed by student &# 39 ; s t - test . fig3 shows the retention time of has in gpc diagram . the vertical axis represents the retention time in gpc , the horizontal axis represents the degradation time of ha in artificial gastric juice . the horizontal dotted lines from up to down represent the retention time of 2 mda , 1 mda , 350 kda and 17 kda has , respectively . the retention time was slowly increased followed by the increased degradation of all three has . after 7 hours of degradation , the average molecular weights of hha and mha were degraded to about 1 mda . after 31 hours of degradation , the average mw of mha was degraded to about 350 kda . after 35 hours of degradation , the average mw of hha was degraded to about 350 kda . the aforementioned data all indicate that ha was slowly degraded in the artificial gastric juice whereas the average molecular weights of hha and mha were larger than 1 mda after 6 hours of degradation , and the average molecular weights of hha and mha were larger than 350 kda after 24 hours of degradation . the adhesion of ha in colon tissue ( ivis image system - vision 3 ) 1 . lha and hha were prepared as the same as example 1 . mha ( mha ; mw : 1 mda ; freda ) were added into 50 ml pbs buffer , and then stirred for 6 hours until the powder was totally dissolved and ready for use in the following steps . 2 . fluorescent ha ( ha - f ) was prepared by ( 1 ) 0 . 39 g mes free acid ( 2 -( n - morpholino ) ethanesulfonic acid , calbiochem ) and was dissolved in 100 ml dd water . ( 2 ) solution a : 65 mg fluroresceinamine powder , ( isomer i , fluka ) was dissolved in 9 ml 95 % etoh solution and then stirred for 10 minutes under a condition that light was prohibited . ( 3 ) solution b : 359 mg edc powder ( n -( 3 - dimethylamino propyl )- n - ethyl carbodiimide hydrochloride , sigma ) was dissolved in 9 ml mes buffer and then stirred for 10 minutes . ( 4 ) solution c : 216 mg nhs powder ( n - hydroxysuccinimde , sigma ) was dissolved in 9 ml mes buffer and then stirred for 10 minutes . ( 5 ) 3 ml solution a was slowly dropped into 50 ml 0 . 5 % ha solution and then stirred for 10 minutes under a condition that light was prohibited . ( 6 ) 3 ml solution b and 5 ml solution c were separately dropped into the solution of step ( 5 ) and then stirred for 10 minutes under a condition that light was prohibited . ( 7 ) 0 . 02 m mes buffer was slowly added into the solution of step ( 6 ) until the volume reached 100 ml and then stirred for 24 hours at room temperature under a condition that light was prohibited . ( 8 ) the product after reaction was poured into a dialysis tubing ( mw : 12000 ˜ 14000 ) in 5 l dd water as a dialysis solution and then stirred for 5 days at 4 under a condition that light was prohibited with dialysis solution being changed every 12 hours until the dialysis solution had no fluorescence . ( 9 ) the liquid after dialysis was allocated into 50 c . c . plastic centrifuge tubes and then reserved at − 20 ° c . refrigerator overnight followed by drying in a freeze - drying machine under a condition that light was prohibited . ( 10 ) the dried ha - f powder was reserved at − 20 ° c . refrigerator . ( 11 ) 50 mg ha - f powder was slowly added into 10 ml pbs buffer and then stirred for 6 hours until the powder was totally dissolved . 3 . colon tissue of sd - rat ( sprague - dawley rat ) aged 7 - 8 weeks was cut by scalpel and then washed by pbs buffer followed by being cut to 3 - 4 cm long with soaking in pbs buffer finally . 4 . injured colon tissue was prepared by brushing by toothbrush for 20 times longitudinally and then soaking in pbs buffer . 5 . normal and injured colon tissues were put into a 12 - well plate and then 1 ml 0 . 5 % ha - f solution was added into each well and shaken for 2 hours at room temperature . surplus ha - f solution was sucked by tip 2 hours later , and then soaked into pbs buffer for 10 minutes followed by removing pbs buffer repeatedly for 3 times . 6 . cleaned colon tissue was placed in a 12 - well plate with lining tissue upwards and then placed onto the dock of the ivis ( in vivo image system , xenogen ). the default parameter was set up as gfp ( green fluorescent protein ) whereas the excitation was 465 nm and the emission was 500 nm and then the image was captured by software . 7 . all values in the table are expressed as means of n observations . the histological index was analyzed by student &# 39 ; s t - test . result : the fluorescent index was quantified and arranged as in fig4 . the fluorescent index of normal colon tissue was defined as 1 . the other colon tissues tests were calibrated by the defined value . the result showed that the has with the same average mw were absorbed in the injured colon tissues obviously higher than in the normal colon tissues ( p & lt ; 0 . 01 ). in comparing the difference between has of three different average molecular weights absorbed in the injured colon tissues , the fluorescent index of absorption of 350 kda ha by the injured colon tissues was obviously higher than has of the other two average molecular weights ( 2 mda and 1 mda ). further , the fluorescent index of absorption of 1 mda ha by even normal or injured colon tissues was higher than 2 mda ha . the body weight change of rat with or without administration of ha aimed at colitis 1 . test purpose : to induce the colitis in the spf grade sd ( sprague - dawley ) rats with the tnbs in order to evaluate the effect for treating or preventing colitis by two kinds of mixing has differing in weight proportion . 2 . test objective : ibd98 , comprising lmwha and hmwha , whereas the hmwha was 2 million da and the lmwha was 350 kilo da , mixed in the ratio of 8 : 2 and 1 : 1 by weight which were categorized into group a and group b , respectively , and dissolved in pbs solution to produce a concentration of 0 . 125 % ( w / v ). 3 . method : ( 1 ) test target : rats aged 8 weeks were selected , and classified into three groups : group a represented mixing ratio of 8 : 2 ; group b represented mixing ratio of 1 : 1 ; group c was treated by pbs instead of ha . ( 2 ) animal test : all rats of the treating group were fasted for 2 days ; in test day 1 , the rats were anesthetized for administrating 1 ml of tnbs ( 50 mg / ml ) via the rectum ; through test days 4 to 14 , administering 1 ml of two categories of ibd98 via the rectum in groups a and b ; in test day 9 , the body weight changes of half rats in groups a and b were observed . and the body weight changes of the other half rats were observed in day 14 . all rats of the control group were fasted for 2 days ; in test day 1 , the rats were anesthetized for administrating 1 ml of tnbs ( 50 mg / ml ) via the rectum ; in test days 4 to 14 , administering 1 ml of pbs via the rectum ; in test day 9 , the body weight changes of half rats in group c were observed . and the body weight changes of the other half rats were observed in day 14 . 1 . inflammatory index : the present invention used changes of average body weight as an index to view the amelioration of colitis ( ibd ). the change of the body weight is a convenient and direct index to check the treatment result . 2 . the trend showed groups a and b both had relief effects on colitis which also represented ibd through day 1 to day 14 ( fig5 a and 5b ). in average weight changes between control and has , treatment effect of colitis caused the average body weights of group by administered has to be kept higher than those of control group during the whole experimental period even till test day 14 ( fig5 b ). 1 . test purpose : to induce the allergic disease , herein rhinitis , in the spf grade sd ( sprague - dawley ) rats . 2 . test objective : ibd98 , comprising lmwha and hmwha , whereas the average molecular weight of hmwha is 2 million da and the average molecular weight of lmwha is 350 kilo da , mixed in the ratio of 1 : 1 by weight dissolved in pbs solution to produce a ha solution at a concentration of 0 . 125 % ( w / v ). 3 . method : ( 1 ) test target : nine rats aged 8 weeks were selected , and classified into two groups randomly : control group ( pbs ) consisted of 4 rats and the test group ( ha ) consisted of 5 rats . ( 2 ) animal test : during test day 1 to day 7 , the rats were intra - peritoneally ( ip ) injected with physiological saline containing ovalbumin ( 1 mg ) and alum ( 10 mg ) in each day ; just observing through test day 8 to day 13 ; during test day 14 to day 27 , dripping ovalbumin in saline solution ( 10 μg / 10 μl / nostril ) into bilateral nasal cavities by micropipette . the effect of ha on the nasal symptoms after antigen challenge were evaluated with rats on day 28 ( d28 ) and day 30 ( d30 ) after general sensitization . before 1 hour of the instillation of ovalbumin , the animals were dripped with the ha solution or pbs ( 25 μl / nostril ). after nasal instillation of ovalbumin in saline ( 10 μg / 10 μl / nostril ) into the bilateral nasal cavities , the animals were placed in the observation cage ( 1 animal / cage ), and nasal rubbing were counted for 30 minutes . the nasal rubbing frequency was calculated as the times of nasal rubbing per 30 minutes . 1 . allergic amelioration index : the present invention used the nose rubbing frequency as an index of allergic amelioration . 2 . the effect of the ha sample on the antigen - induced nasal symptoms were shown in fig6 . the average nasal rubbing frequency induced by ovalbumin was 56 . 25 ± 16 . 1 times / 30 minutes on day 28 ( d28 ) and 70 . 0 ± 41 . 3 times / 30 minutes on day 30 ( d30 ). compared with the control group , nasal rubbing was reduced significantly by the ha solution on day 28 and obviously reduced on day 30 .