Design and synthesis of chitosan/agar/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

Abstract

In this work we have demonstrated the green synthesis of stable and mono-dispersed Ag NPs using chitosan/Agar hydrogel having reducing/stabilizing ability avoiding any toxic reagents. Agarose was used as a green reductant for the synthesis of Ag NPs which gets stabilized by chitosan. The in situ prepared Ag NPs@CS/Agar nano bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. The Ag NPs encapsulated by CS/Agar bio-composite have a spherical shape with a mean diameter from 10 to 15 nm. Towards its bioapplication, the Ag NPs@CS/Agar nano bio-composite was administered by 5 µg/kg/day for 30 days in comparison to methyl prednisolone sodium succinate by 10 mg/kg, sc, thrice a week for 4 weeks over Wistar rats having glucocortcoid induced osteoporosis. This showed a significant increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An inclination in strength of femur and tibia was seen particularly with 5 µg/kg of Ag NPs@CS/Agar nano bio-composite. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can be the plausible mode of action of this bio-nanocomposite thereby combating osteoporosis induced by glucocorticoids.