Preparation And Evaluation Of A Biodegradable Medical Film For Preventing Post-surgical Adhesion

Intraperitoneal adhesion formation occurs in about 90%of patients after intra-abdominal surgery,which usually causes serious complications.In this thesis,a new composite medical anti-adhesion membrane with good biocompatibility and natural degradation in the body was prepared by using natural polymer material carboxymethyl chitosan(CMCs),carboxymethyl cellulose(CMCl)and collagen(COL)as matrix.Firstly,the non-crosslinked CMCs/CMCl/COL composite films with different mass ratios of raw materials were prepared,and their hydrophilic properties as well as mechanical strength were investigated.It was found that the non-crossl inked CMCs/CMCl/COL composite films had poor water resistance and mechanical properties,which was difficult to meet the requirements of medical anti adhesion film.Secondly,a transglutaminase(TGases)-catalyzed CMCS/CMCL/COL composite membrane with various proportions of CMCS,CMCL,and COL were developed,and the physical properties and cell compatibility were measured.The results showed that the properties of the crosslinked CMCs/CMCl/COL composite film with mass ratio of 25/25/50 were better than those of 40/40/20 and 35/35/30.It was showed that the water absorption rate of the film was between 2181%-2856%,the contact angle of the film was 74.62 ± 3 °,the tensile strength of the film was 8.38 ± 0.59 MPa,the elongation at break of the film was 122.65 ± 2.86%.and the natural degradation time in vitro was about 35 days,which was in line with the requirements of the anti-adhesion film of the medical abdominal cavity.In addition,high cytocompatibility of the film was demonstrated by in vitro human skin fibroblast(HSF)cells culture study.Finally,Wistar rats were selected to establish the postoperative adhesion model to investigate the function of the crosslinked CMCs/CMCl/COL anti-adhesion membrane.The experimental results showed that the composite membrane could significantly reduce the incidence of postoperative adhesions in rats,and the wound healing rate was fast.H&E staining and Masson staining showed that the inflammatory cell infiltration and collagen deposition in the composite membrane group were significantly lower than those of the control group,And the serum test results showed that the level of hydroxyproline(Hyp)in the composite membrane group was significantly lower than that in the control group,and the ALT level was also normal,which indicating that the composite membrane had no side effects on the body.In addition,the membrane was almost completely degraded in third weeks after operation,indicating that the membrane had good biodegradability.In summary,the CMCs/CMCl/COL medical film crosslinked by TGase has strong mechanical strength and physical properties,which reaches requirements of medical anti-adhesion membrane in the aspects of degradability and biocompatibility.The rat experiment shows that the medical anti-adhesion membrane can effectively prevent postoperative abdominal adhesion.