Enhancement of bone ingrowth in a titanium fiber mesh implant by rhBMP-2 and hyaluronic acid

Abstract

The present study was designed to evaluate the efficacy of high molecular weight hyaluronic acid (HA) used as a carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) adsorbed to a titanium fiber mesh implant (TFMI) in vivo. The quantity of HA in the TFMI rapidly decreased during the initial 3-day period after implantation. BMP particles were trapped by the meshwork of HA as observed by scanning electron microscopy (SEM). TFMIs containing LF-6, HA, rhBMP-2, or HA combined with rhBMP-2 were implanted on the cranium of rats. Analysis of digitized SEM images of samples obtained six weeks post-implantation was performed to determine the area occupied by new bone. The area fraction of Ca relative to that of the pores of TFMI in the HA group was larger than that in the Ti group (p<0.05). The area fraction of Ca in both the BMP and HA+BMP groups was larger than that in both the Ti and HA groups (p<0.01), and that in the HA+BMP group was larger than that in the BMP group (p<0.05). It is suggested that HA is not only an effective carrier of BMP, but also it may have a positive effect on the generation of new bone in the TFMI.