RESUMO
Objective:To evaluate the anti-adhesion properties of xyloglucan(mXG)hydrogel in the L929 mouse fibroblasts,to establish the animal model of recurrent adhesion in the rats after adhesionlysis,and to investigate the prevention effect of mXG hydrogel in recurrent adhesion and its influence in the expressions of transforming growth factor-β1(TGF-β1)and connective tissue growth factor(CTGF).Methods:After seeding on the surface of mXG gel,the adhesion property of L929 mouse fibroblasts was detected with fluorescence staining.The rat models of recurrent adhesion were established after adhesionlysis.Fourty-eight SD rats were randomly divided into 3 groups respectively(n=16).In adhesion group,1 mL saline was injected into the abdominal wall and cecum of the rats;in commercial membrane group,the 2 cm×3 cm chitosan anti-adhesion membrane was used to cover the wound of abdominal wall of the rats;in mXG hydrogel group,1 mL 4% mXG hydrogel was injected into the abdominal wall and cecal wound of the rats,and abdominal surgery was ended after the complete formation of the hydrogel(3 min).Eight rats were killed in each group 7 and 14 d after the second operation,and the degrees of adhesion were evaluated and the histological changes were observed. Immunohistochemical staining was used to observe the expression levels of CTGF and TGF-β1.Results:A large number of L929 mouse fibroblasts proliferated well and exhibited a spherical morphology in control group;but in mXG hydrogel group,only very little L929 mouse fibroblasts were globular,showing the mXG hydrogel had good resistance to the adhesion of L929 mouse fibroblasts.Blunt separate adhesion surface formed in all of the rats after operation.7 d after the second operation,4-5 score adhesion with fibrous connective tissue hyperplasia formed in adhesion group;moderate adhesion formed in commercial membrane group with more connective tissue;most cecum and abdominal wall began to heal in mXG hydrogel group with less connective tissue.14 d after the second operation,more severe peritoneal adhesions presented in adhesion group with proliferated fiber connetive tissue and collegan;severe adhesions also presented in commercial membrane group;mild adhesion was found in two rats mXG group,the other rats had no adhesion,and the defects were almost completely recovered.On days 7 and 14 after the second operation,the mean adhesion score of the rats in mXG group was significantly lower than those in adhesion group and commercial membrane group(P<0.05).The expression levels of TGF-β1 and CTGF were increased with the increase of peritoneal adhesion scores and collagen deposition;the expression levels of TGF-β1 and CTGF were the highest in adgesion group and the lowest in mXG group.Conclusion:mXG hydrogels have good resistance to fibroblast adhesion,and mXG hydrogel is effective in reducing the formation of recurrent adhesion in the rats after adhesionlysis and can decrease the expression levels of adhesion-related factors TGF-β1 and CTGF.
RESUMO
Objective: To evaluate the anti-adhesion properties of xyloglucan (mXG) hydrogel in the L929 mouse fibroblasts, to establish the animal model of recurrent adhesion in the rats after adhesionlysis, and to investigate the prevention effect of mXG hydrogel in recurrent adhesion and its influence in the expressions of transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). Methods: After seeding on the surface of mXG gel, the adhesion property of L929 mouse fibroblasts was detected with fluorescence staining. The rat models of recurrent adhesion were established after adhesionlysis. Fourty-eight SD rats were randomly divided into 3 groups respectively (n=16). In adhesion group, 1 mL saline was injected into the abdominal wall and cecum of the rats; in commercial membrane group, the 2 cm × 3 cm chitosan anti-adhesion membrane was used to cover the wound of abdominal wall of the rats; in mXG hydrogel group, 1 mL 4% mXG hydrogel was injected into the abdominal wall and cecal wound of the rats, and abdominal surgery was ended after the complete formation of the hydrogel (3 min). Eight rats were killed in each group 7 and 14 d after the second operation, and the degrees of adhesion were evaluated and the histological changes were observed. Immunohistochemical staining was used to observe the expression levels of CTGF and TGF-β1. Results: A large number of L929 mouse fibroblasts proliferated well and exhibited a spherical morphology in control group; but in mXG hydrogel group, only very little L929 mouse fibroblasts were globular, showing the mXG hydrogel had good resistance to the adhesion of L929 mouse fibroblasts. Blunt separate adhesion surface formed in all of the rats after operation. 7 d after the second operation, 4-5 score adhesion with fibrous connective tissue hyperplasia formed in adhesion group; moderate adhesion formed in commercial membrane group with more connective tissue; most cecum and abdominal wall began to heal in mXG hydrogel group with less connective tissue. 14 d after the second operation, more severe peritoneal adhesions presented in adhesion group with proliferated fiber connetive tissue and collegan; severe adhesions also presented in commercial membrane group; mild adhesion was found in two rats mXG group, the other rats had no adhesion, and the defects were almost completely recovered. On days 7 and 14 after the second operation, the mean adhesion score of the rats in mXG group was significantly lower than those in adhesion group and commercial membrane group (P<0.05). The expression levels of TGF-βl and CTGF were increased with the increase of peritoneal adhesion scores and collagen deposition; the expression levels of TGF-βl and CTGF were the highest in adgesion group and the lowest in mXG group. Conclusion: mXG hydrogels have good resistance to fibroblast adhesion, and mXG hydrogel is effective in reducing the formation of recurrent adhesion in the rats after adhesionlysis and can decrease the expression levels of adhesion-related factors TGF-βl and CTGF.
RESUMO
The aim of this study was to improve the mucoadhesive potential of xyloglucan polymer by the covalent attachment of cysteine as thiol moiety. The parent polymer xyloglucan was chemically modified by introducing sulphydryl bearing compound L-cysteine HCl. Different batches of xyloglucan-cysteine conjugates were prepared at varying reaction pH (2-6) and evaluated for optimum thiol incorporation, disulphide group content, swelling behavior, rheological properties and mucoadhesive properties. The obtained conjugates characterized in vitro by quantification of immobilized thiol groups; showed maximum thiol incorporation on xyloglucan (7.67 ± 0.14 %) at pH 5. The disulphide group content was found maximum (2.83 ± 0.12) at pH 6. The water uptake at end of 4 h was 5.0 for xyloglucan and was found to decrease in thiolated derivatives with increase in thiolation. Mucoadhesion studies revealed that mucoadhesion of xyloglucan-cysteine conjugate increased more than twice compared to the unmodified polymer. The viscosity of thiomer was more than that of xyloglucan because of formation of disulphide bonds.
O objetivo deste estudo foi melhorar o potencial mucoadesivo do polímero xiloglicano pela ligação covalente de cisteína como unidade de tiol. O polímero xiloglicano foi quimicamente modificado pela introdução de cloridrato de cisteína como grupo contendo sulfidrila. Prepararam-se diferentes lotes de conjugados cisteína-xiloglicano em pH variando de 2 a 6, avaliando-se a incorporação ótima de tiol, o conteúdo de dissulfeto, o comportamento de inchamento, as propriedades reológicas e mucoadesivas. Os conjugados obtidos foram caracterizados in vitro pela quantificação de grupos tiol, mostrando máxima incorporação na xiloglicana (7.67 ± 0.14 %) em pH 5. O conteúdo de grupos dissulfeto foi máximo (2.83 ± 0.12) em pH 6. O índice de inchamento em % no fim de 4 h foi 83.87 para o xiloglicano e diminuiu para os derivados tiolados. O conteúdo foi mínimo para TH2 (78.26), aumentou pouco até TH5 (83.33) e diminuiu, posteriormente, para TH6 (80.13). Os estudos de mucoadesão revelaram que o conjugado xiloglicano-cisteína aumentou mais que duas vezes comparativamente ao polímero não modificado. A viscosidade do tiômero foi maior do que a do xiloglicano devido à formação das ligações dissulfeto.