Rapid fabrication of bio-inspired, mineralized polysaccharide coatings

Bio-inspired, mineralized polysaccharide coatings consisting of interspaced alginate–chitosan and calcium phosphate carbonate planar composite films were rapidly fabricated via electrostatic layer-by-layer (LBL) self-assembly and organic-matrix-mediated nucleation and growth. Experimental design, a fractional factorial design (2^8-4), was used to identify the optimum LBL film process parameters for fast film growth. Calcium phosphate carbonates rapidly precipitated on the fast growing LBL films from a supersaturated solution in around 15 min. The number of bilayers of LBL films and soaking time in calcium phosphate carbonate solution were found to affect the morphology of calcium phosphate carbonates, indicating a complex, organic matrix mediated mineralization process. The coating protocol in the current study was readily transferable to a variety of template geometries and materials. The resulting planar composite coatings could be applied for the modification of orthopaedic and periodontal implant surfaces and also for controlled growth of hematopoietic or mesenchymal stem cells.