Canal wall down (CWD) mastoidectomy is a surgical procedure that is essential to eradicate chronic ear diseases but results into bone defects due to the resulting mastoid cavity. This study investigated the ability of human tonsil-derived mesenchymal stem cells (hTMSCs) combined with a hydroxyapatite (HAp)-chitosan patch to promote osteogenesis in the treatment of postoperative temporal bone defects using an animal model. At 12 weeks postsurgery, the obliteration ratio and bone formation in the tympanic bulla of rats that were grafted with hTMSCs and a hydroxyapatite (HAp)-chitosan patch or not were compared using histopathological observation and computed tomography (CT) imaging. The group of rats that was administered the Patch group and the group of rats that was administered hTMSCs + Patch group both showed significantly remarkable obliteration ratios and bone formation compared with the Sham and hTMSCs groups. Moreover, the hTMSCs + Patch group showed bone formation in both the periphery and the central region of the tympanic bulla cavity, indicating prominently enhanced osteogenesis compared to the Patch group. Altogether, the results showed that combining hTMSCs with a HAp-chitosan patch accelerated osteogenesis for reconstruction of postoperative temporal bone defects. These findings demonstrate that the hTMSCs + Patch scaffolds are promising for treatment of the bone defects in the tissue engineering.
Keywords: chitosan; hydroxyapatite; mastoidectomy; mesenchymal stem cells; osteogenesis.