Biowaste-derived hydroxyapatite reinforced with polyvinyl pyrrolidone/aloevera composite for biomedical applications

The present investigation focuses on the synthesis of crabshell-derived hydroxyapatite (CS-HAP)/ water-soluble synthetic polymer—polyvinylpyrrolidone(PVP)/aloevera(AV)—a natural biopolymer, as a composite for enhanced mechanical, antibacterial and biocompatible properties. The reinforcement of polymer has a significant function in increasing the mechanical property of the composite, whereas the incorporation of AV improves the antibacterial and biocompatibility. Phase composition, morphology, mechanical property, and hydrophilicity of CS-HAP/PVP/AV biocomposite with different concentrations of PVP and AV were examined by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray (SEM-EDX), Vickers microhardness tests, contact angle, respectively. Furthermore, the antibacterial efficiency of the composite is assessed using Escherichia coli (E coli) and Staphylococcus aureus (S aureus). The biocompatibility of HOS MG 63 cells on the CS-HAP/PVP/AV composite is evaluated by MTT assay test. The obtained results evidence that the as-synthesized composite have appropriate mechanical, antibacterial and biocompatible properties. Overall, the combination of mechanical property of PVP, antibacterial and biocompatible property of AV in CS-HAP/PVP/AV, makes the composite a potential therapeutic material for various biomedical applications.     

A facile electrodeposition of hydroxyapatite onto borate passivated surgical grade stainless steel

This paper reports a successful electrodeposition method for coating hydroxyapatite (HAP) onto surgical grade stainless steel (SS). Pure HAP coatings could be achieved at −1400 mV vs SCE and the coating resistivity was assessed by potentiodynamic polarization and impedance techniques which showed that HAP coatings deposited onto the borate passivated-SS specimens possess maximum bioresistivity in Ringer’s solution. The coatings were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM). The results have showed that the borate passivation followed by HAP coating performed on 316L SS could enhance the longevity of the alloy in Ringer’s solution.