Biomimetic fabrication of a native fibrillar collagen composite for bone tissue engineering

Abstract

Due to increasing demand for bone implants, conventional tissue replacements cannot meet the quantity and performance needed by patients. Bone is a complex tissue composed of hydroxyapatite [Ca10(PO4)6(OH)2, HAp] and collagen. Approximately 30% of dry bone is oforganic materials, about 95% of which is collagen type I. Collagen, the main organic component of the Extracellular Matrix (ECM), induces positive effects on cellular attachment, proliferation, and differentiation of many cell types. As the main inorganic component of bone, HAp has been widely used in many orthopaedic and dental implant materials because of its bioactive, osteoconductive, and osteoinductive properties. Compared with other HApbiodegradable polymer composites, HAp-collagen composites have been approved as a bioactive and biodegradable scaffold due to their chemical and structural similarity to bone. Collagen-HAp composites are usually prepared by physical mixing of pre-synthesized HAp particles with collagen. Oyane et al. have also reported that modified Simulated Body Fluid (m-SBF) can be used for the preparation of biomimetic hydroxyapatite. However, collagen scaffolds prepared without reconstitution into native form as in the above mentioned studies, are inferior in mechanical property and wound healing applications. Another difficulty in calcified tissue repair is the probability of infection given the large surfaces exposed during hip implant surgery and silver ions have been shown to be effective in controlling this. Silver nanoparticles with high specific surface area having more efficient ion release can be incorporated onto collagen scaffolds to treat bone defects. newline