Novel biocomposite based on functionalized poorly crystalline apatite and chitosan: A physicochemical evaluation

The lack of the required mechanical strength and adequate biodegradation rate of calcium phosphate materials constitutes the most relevant drawback prohibiting their use for orthopaedic applications. One of the promising strategies to overcome this intrinsic limitation is the functionalization of these materials through the combination with specific functional groups. In this study, we investigated APTES (3-aminopropyl-triethoxy-silane) functionalization of a poorly crystalline apatite (PCA) and its further combination for the first time to chitosan (CS) to elaborate PCA-APTES-CS functionalized composite material. XRD patterns of the elaborated materials exhibit broad peaks typical of poorly crystalline apatite. FTIR spectroscopy showed, in addition to the PCA characteristic bands, bands assigned to silane alkyl groups and evidenced the success of functionalization process. The TGA analysis confirmed the attachment of 8 wt% of APTES and 3 wt% of chitosan within the composite. SEM microscopy and EDX silicon mapping demonstrated a homogeneous silane presence on functionalized apatite surface and showed that chitosan enveloped the functionalized apatite particles surface. The elaborated PCA-APTES-CS functionalized composites exhibited compressive strength similar to the spongy bone. The functionalized biocomposite will be investigated as potential biomaterial for orthopedic application.