Construction of PVA/OHA-Gs@PTMC/PHA double-layer nanofiber flexible scaffold with antibacterial function for tension free rectal in-situ reconstruction.

The effective prevention and treatment of anastomotic leakage after intestinal anastomosis for colorectal diseases is still a major clinical challenge. In order to assist intestinal anastomosis healing and avoid anastomotic leakage caused by high tension, low blood supply or infection, we designed a double-layer nanofiber intestinal anastomosis scaffold, which was composed of electrospun PTMC/PHA nanofibers as the main layer, and electrospun PVA/OHA-Gs nanofibers with antibacterial properties as the antibacterial surface layer. This double-layer scaffold has good toughness, its maximum tensile force value could reach 8 N, elongation could reach 400 %, and it has hydrophilic properties, and its contact angle was about 60°. On the basis of reducing anastomotic tension and isolating intestinal contents, this double-layer nanofiber anastomotic scaffold not only played an antibacterial effect in the short term after surgery to reduce inflammatory response, but also had the characteristics of multiple three-dimensional network structure like extracellular matrix which could promote tissue healing. The PVA/OHA-Gs@PTMC/PHA scaffold was implanted into a rabbit model simulating mechanical intestinal obstruction, and the results showed that the nanofibers of the scaffold could be degraded in vivo while maintaining a certain stability, that is, the overall structure of the PVA/OHA-Gs@PTMC/PHA scaffold would not shrink and deform due to degradation in a certain period of time. Therefore, the treatment with this scaffold showed better healing at the anastomotic site. Compared to the direct anastomosis group and pure PTMC scaffold group, the double-layer scaffold group promoted a faster return to normal anastomotic strength within 7 days. This PVA/OHA-Gs@PTMC/PHA double-layer nanofiber flexible scaffold appears to be a promising therapeutic strategy to prevent anastomotic leakage after intestinal anastomosis.