Biomimetic chitosan–calcium phosphate composites with potential applications as bone substitutes: Preparation and characterization

Abstract

A novel biomimetic technique for obtaining chitosan-calcium phosphates (Cs-CP) scaffolds are presented: calcium phosphates are precipitated from its precursors, CaCl(2) and NaH(2) PO(4) on the Cs matrix, under physiological conditions (human body temperature and body fluid pH; 37°C and pH = 7.2, respectively). Materials composition and structure have been confirmed by various techniques: elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). FTIR and SEM data have shown the arrangement of the calcium phosphates-hydroxyapatite (CP-Hap) onto Cs matrix. In this case the polymer is acting as glue, bonding the calcium phosphates crystals. Behavior in biological simulated fluids (phosphate buffer solution-PBS and PBS-albumin) revealed an important contribution of the chelation between -NH3(+) and Ca(2+) on the scaffold interaction with aqueous mediums; increased quantities of chitosan in composites permit the interaction with human albumin and improve the retention of fluid. The composites are slightly degraded by the lysozyme which facilitates an in vivo degradation control of bone substitutes. Modulus of elasticity is strongly dependent of the ratio chitosan/calcium phosphates and recommends the obtained biomimetic composites as promising materials for a prospective bone application.

Cell interactions between human progenitor-derived endothelial cells and human mesenchymal stem cells in a three-dimensional macroporous polysaccharide-based scaffold promote osteogenesis

“…They have great design flexibility, owing to their composition, and their structure can be tailored to a specific need [39]. Several studies on bone tissue engineering using polysaccharides such as alginate, carrageenan, chitosan, pullulan or cellulose [40][41][42][43][44][45] are in progress. These natural polymers hold promise for healing and regenerating damaged tissues, since they are highly permeable and facilitate the transport of nutrients and metabolites [46].…”

Comparative study of porous hydroxyapatite/chitosan and whitlockite/chitosan scaffolds for bone regeneration in calvarial defects

“…Chitosan, an ideal biomaterial with excellent biocompatibility and antibacterial capability, has been widely applied in tissue engineering and bone repair. [15][16][17][18][19] Therefore, we chose chitosan as the organic phase to fabricate the inorganic/organic composite porous scaffold for bone regeneration. First, we prepared HAP and WH hollow microspheres by using creatine phosphate (CP) disodium salt as an organic phosphorus source in aqueous solution by microwave-assisted hydrothermal method.…”

Evaluation of in vitro and in vivo osteogenic differentiation of nano‐hydroxyapatite/chitosan/poly(lactide‐co‐glycolide) scaffolds with human umbilical cord mesenchymal stem cells

“…18,19 Moreover, the CS with many active groups provides a cell recognition signal and the positive charges on the CS surface to attract negatively charged cells. 20 In this study, alkaline phosphatase (ALP) is a membrane bound enzyme that is abundant in the early stages of bone formation. And, in the matrix maturation phase, the increased ALP levels correlate with increased bone formation, histomorphometrically.…”