Insight into the synthesis of biocompatible polymer for collagen stabilization and leather process

Collagen-based biomaterials are highly effective owing to their high biocompatibility and non-immunogenicity, but their biological application is still constrained because of poor thermal stability. The greener crosslinkers devoid of aldehydes and toxic precursors have recently evoked considerable interest. In this work, biocompatible and multifunctional carboxyl polymer (MCP) has been synthesized by a simple one-step carboxylation reaction by modifying the hydroxyl group in the monomer, followed by polymerization in aqueous conditions. The synthesized polymer has been used for both collagen stabilization and leather processing. The circular dichroism studies revealed a significant change in the secondary structure of the collagen with increasing concentration of the MCP, and thermal stability of the rat tail tendon is enhanced up to 70 °C. The application of MCP as a crosslinker for collagen in the leather-making process along with metal salts increased the leather's thermal stability and improved uptake of the metal salts. The interaction mechanism of MCP and the metals during the tanning process is through complexation with carboxyl pendants available on the MCP backbone, as confirmed by UV–Visible and IR spectroscopy. The experimental leathers showed a uniform penetration of tanning agents and excellent mechanical properties compared to the control leathers. Further, biocompatibility studies using 3 T3 fibroblast cells revealed that the MCP did not induce any significant cytotoxicity with cell viability of 96%, confirming the non-toxic nature of the synthesized polymer. Thus, the current study opens a new path for sustainable alternative polymeric crosslinkers for collagen stabilization and its potential application in biomaterial and leather-making fields.