Preparation of polysaccharide-apatite hybrid microtubes using layer-by-layer assembly and biomimetic mineralization process.

Organic-inorganic hybrid microtubes were prepared that consisted of polysaccharide inner layers and hydroxyapatite (HAp) outer layers. Poly(methyl methacrylate) (PMMA) fibers containing small amounts of polyethyleneimine (PEI) were used as templates for the layer-by-layer (LbL) assembly of chondroitin sulfate C and chitosan. HAp layers were then deposited on polysaccharide layer-coated fibers using biomimetic processes. PMMA-PEI fiber templates were removed by immersing the samples in chloroform. Examination of the resulting materials using various physical characterizations such as scanning electron microscopy, FT-IR spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction studies supported the successful formation of the hybrid microtubes as designed. The results also showed that incorporation of PEI into PMMA fiber matrices was effective in inducing HAp deposition. The present procedure can be applied to the preparation of various hybrid microtubes consisting of biocompatible organic inner layers formed using LbL assemblies and HAp outer layers. Some of these hybrids have potential applications in regenerative medicine or tissue engineering.