Biomimetic nanocomposite based on hydroxyapatite mineralization over chemically modified cellulose nanowhiskers: An active platform for osteoblast proliferation

Abstract Functionalized-cellulose nanowhiskers (CNWs) were obtained and used to improve hydroxyapatite (HAp) growth by the biomimetic method. CNWs were obtained through HCl hydrolysis and then submitted to chemical functionalization with carboxylate or amine groups that can induce selective HAp mineralization efficiently. Functionalized-CNWs were tested against HAp growth through the biomimetic method using a simulated body fluid (SBF) as a medium during 14 and 28 days of mineralization. Both chemical surface nature (bearing carboxylate or amine reactive groups) and contact time with SBF influenced the nucleation and growth of HAp crystals over CNWs surface. Nanocomposites immersed for 28 days showed a higher amount of HAp crystals compared to bare CNWs or the ones immersed for 14 days. Biocompatibility of the nanomaterials immersed for 14 days in SBF was evaluated through cell viability test using pre-osteoblasts (MC3T3-E1). In general, functionalized-CNWs containing HAp crystals deposited through biomimetic method showed promising results, with CNWs bearing amine groups showing a slightly larger biocompatibility compared to the ones bearing carboxylate groups during an incubation period of 24 h.