Effects of methoxy polyethylene glycol‐polycaprolactone block copolymers and silica nanoparticles on the mechanical, tissue affinity and antibacterial properties of n‐butyl cyanoacrylate adhesive

Abstract

Cyanoacrylates are widely used as surgical tissue adhesives because of their high biodegradability, but they are brittle and have poor tissue affinity. In this study, methoxy polyethylene glycol‐polycaprolactone block copolymers (MPEG‐co‐PCLs) with different PCL chain lengths were synthesized by ring‐opening polymerization. Then, a new tissue adhesive with excellent mechanical properties, tissue affinity, antibacterial properties, and coagulation performances was prepared by incorporating MPEG‐co‐PCL and silica nanoparticles (SNPs) into n‐butyl cyanoacrylate (BCA). The optimal MPEG: PCL ratio is 1:4 (MP‐3), and the optimal mass ratio of MPEG‐co‐PCL and SNPs (0.5SNPs/0.5MP‐3) is 0.5 wt.%. Compared to BCA, the adhesion strength and flexibility of 0.5SNPs/0.5MP‐3 are dramatically improved by 110% and 244%, respectively. MPEG‐co‐PCL can fully exploit the advantages of homopolymers, and therefore, improve the tissue affinity and adhesion strength of the adhesive and avoid BCA polymerization initiated by MPEG and poor compatibility of PCL with BCA. SNPs can also compensate for the lack of antibacterial properties of BCA against Gram‐negative bacteria. The E. coli inhibition circle of 0.5SNPs/0.5MP‐3 is twice as large as BCA. SNPs can also improve coagulation by promoting platelet aggregation. This work provides an effective strategy for developing adhesives with potential clinical applications.