Optimization of hydroxyapatite (HAp) extraction from scales of Sardinella longiceps and its conjugative effect with immunostimulants

Abstract

Hydroxyapatite [Ca10(PO4)6(OH)2] (HAp) has been regarded as a bone mineral, which acts as a grafting material due to its similar chemical composition with natural bones. HAp is thermodynamically stable at physiological pH and actively takes part in bone bonding. This property led has lead to HAp being widely used for rapid bone repair. HAp is derived from natural bio wastes such as fish scale which is the most definite standard source of both organic and inorganic constituents like collagen and hydroxyapatite. Titanium biomimetic method with the immersion of Stimulated Body Fluid solution were also used widely used for the precipitation of hydroxyapatite synthetically. Hence scales of Sardinella longiceps and titanium are chosen to be the essential source for the isolation of hydroxyapatite (HAp) in this current study. X-Ray Diffraction, Fourier-Transform Infrared spectrometry, Scanning Electron Microscopy confirms the phase, structural integrity and size of isolated HAp. Biocompatibility and calcium deposit assay with osteoblast cell line demonstrates the non-toxicity and efficiency of calcium deposits by HAp scales rather than synthetically derived Titanium mediated HAp. Hydroxyapatite can be doped with bactericidal silver nitrate and a biopolymer, bioadsorbable chitosan for the controlled release, targeted delivery, and corrosion resistance.