Hybrid Networks of Hyaluronic Acid and Poly(trimethylene carbonate) for Tissue Regeneration

To improve the mechanical performance of hyaluronic acid (HA)-based hydrogels, we prepared novel hybrid hydrogels consisting of hydrophilic HA and hydrophobic poly-(trimethylene carbonate) (PTMC). Both polymers were function-alized with methacrylic anhydride, yielding HAMA and PTMC-tMA. Hybrid networks with different ratios of PTMC-tMA:HAMA were prepared by photo-cross-linking, using DMSO pH 2.7 as a common solvent for both macromers. The hybrid networks had high gel contents. The hydrophilicity of the networks increased with increasing HAMA content. The networks consisted of the intended amounts of both macromers. The suture retention strength and compression modulus of the networks increased with increasing PTMC-tMA content. While the 100% HAMA network could not be sutured, the 50:50 PTMC-tMA:HAMA network had a suture retention strength of 5.3 N/mm. This is comparable to that of natural vascular tissues. Also the compression modulus (867 kPa) was significantly higher than that of the 100% HAMA network (13 kPa). Moreover, the networks were compatible with human mesenchymal stem cells. In conclusion, these resilient PTMC-tMA:HAMA networks are promising new biomaterials for tissue regeneration.