Properties of hydroxyapatite - Hyaluronic acid nano-composite sol and its interaction with natural bones and collagen fibers

Biocompatible nano-composite sol (NCS) comprising nano-crystalline hydroxyapatite (HAp, Ca ₁₀(PO4)₆(OH)₂) and hyaluronic acid (HYA) was prepared. By varying the relative content of HAp in NCS, strongest network structure was obtained at 10wt% HAp in NCS, as confirmed from a number of circumstance evidences obtained by rheological, thermoanalytical, crystallographical measurements as well as FT-IR spectra. Interaction of NCS with natural bones and gut strings made from gut collagen was then examined in vitro. Adhesion of the collagen fibers with NCS was observed at the fracture surface of natural bones. Gut collagen was disentangled to the fragments of about 10 nm thick, where no NCS was observed, thus, confirming the fact that the adhesive strength between NCS and bone surface is stronger than that among collagen fibers.