Preparation and characterization of biocompatible polyelectrolyte complex multilayer of hyaluronic acid and poly-l-lysine

A novel biocompatible polyelectrolyte complex multilayer (PECML) was successfully prepared using hyaluronic acid (HA) and poly-l-lysine (PLL). The formation of PECML through the electrostatic interaction of HA as a polyanion and PLL as a polycation was confirmed by contact angle measurement, ESCA analysis and HA content analysis. According to the Carbazole assay, HA content increased rapidly up to eight cycles for HA/PLL deposition and then slightly increased with an increasing number of deposition cycle. In vitro release of PLL from the PECML continued up to 4 days exhibiting different release profiles depending on the outer layer of PECML. This result provides evidence for PLL diffusion throughout PECML of HA and PLL during the multilayer buildup. About 25% of HA remained on the cover glass after the in vitro release test for 7 days. From the results, we confirmed that PECML of HA and PLL could remain at least partially on the chitosan-coated cover glass for 7 days. The surface modification with PECML resulted in drastically reduced peripheral blood mononuclear cell (PBMC) attachment according to the lactate dehydrogenase assay for cell counting. This nano-scale control of material deposition may be successfully applied for surface modification of various biomaterials.