(Hydroxypropyl)methylcellulose mediated synthesis of highly porous composite scaffolds for trabecular bone repair applications

Abstract

This article presents an (hydroxypropyl)methylcellulose (HPMC) mediated synthesis of highly porous scaffolds containing nanocrystalline hydroxyapatite (n-HAp) and chitosan (CS) as major inorganic and organic phases, respectively. A mixture of n-HAp, CS, and HPMC is homogenized and freeze-dried to yield n-HAp/CS/HPMC composite scaffolds closely emulating trabecular bone in density (0.02 g cm-3) and porosity (89%). SEM images substantiate the porous structure of the scaffolds (pore size: 100-300 μm). The mechanical analysis reveal excellent compressive strength of the porous n-HAp/CS/HPMC scaffold (9.65 MPa) that is also comparable with human trabecular bone. The in vitro bioactivity and degradability of the porous scaffolds are investigated in tris-HCl-buffered synthetic body fluid (SBF) and phosphate buffer solution (PBS), respectively. The results indicate a rapid increase in scaffold mass due to apatite-like deposition and good resorbability. The SEM images of SBF soaked samples demonstrate apatite-like deposition on the surface of scaffolds with Ca/P ratio of 1.63 after 7 days of soaking in SBF. These results suggest that porous n-HAp/CS/HPMC scaffolds, due to their structural similarity, mechanical and in vitro biological properties, can become useful alternatives for trabecular bone regeneration and repair.