Injectable hydrogel from plum pectin as a barrier for prevention of postoperative adhesion

Abstract

An injectable hydrogel was obtained from the high methyl-esterified plum Prunus domestica L. (PD) pectin and calcium ions (Ca2+). PD hydrogel showed a weak gel-like behavior and could be squeezed out of the syringe with an injection force of ca. 9 N. PD hydrogel was not suitable for the NIH/3T3 fibroblast cell adhesion in vitro. The live/dead fluorescence and MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assays indicated that the PD hydrogel had a low cytotoxicity in relation to both the adhered and gel surrounding fibroblasts. PD hydrogel was found to inhibit adhesion formation in the sidewall defect-cecum abrasion rat model. In the control group, the occurrence of adhesion of the cecum to the peritoneal wall was found in seven of the total seven rats operated. Only four of the seven animals that were treated with the PD hydrogel were noted to have any adhesions. These adhesions were of a minimum grade of 1, 2, and 3 and were represented by a thin film that could be easily broken. The protective effect of PD hydrogel was found to be comparable with that of hyaluronic acid hydrogel used as a positive control. PD hydrogel appeared to possess enhanced in vivo residence stability on the injury sites compared to hyaluronic acid hydrogel as measured by staining of healing tissue with periodic acid-Schiff reagent. The data obtained offered the prospect for the development of the pectin-based gels as new barrier materials for surgery.