Collagen/nano-sized β-tricalcium phosphate conduits combined with collagen filaments and nerve growth factor promote facial nerve regeneration in miniature swine: an in vivo study.

OBJECTIVE

The aim of this study was to investigate the efficiency of a novel biomedical system that repairs facial nerve gaps in a miniature swine model.

STUDY

DESIGN

A collagen (COL)/nano-sized β-tricalcium phosphate (nβ-TCP) conduit combined with COL filaments and nerve growth factor (NGF) was prepared and used to bridge a 35-mm-long facial nerve gap in miniature swine. The functional recovery and axonal regeneration were evaluated by electrophysiologic and histologic assessments in the different groups at 6 months postoperatively.

RESULTS

Morphologic analysis revealed that the COL+NGF, COL/nβ-TCP+NGF, and autograft groups exhibited a superior recovery compared with the COL and COL/nβ-TCP groups. The compound muscle action potential ratios were significantly greater in the COL/nβ-TCP+NGF group compared to the COL+NGF and COL/nβ-TCP groups (P < .01). Moreover, transmission electron microscopy demonstrated significantly larger axon diameters and myelin sheath thicknesses in the COL/nβ-TCP+NGF group compared with the COL, COL+NGF, and COL/nβ-TCP groups (P < .05). The expression of S-100 was significantly greater in the COL/nβ-TCP+NGF group than in the COL+NGF and COL/nβ-TCP groups (P < .05).

CONCLUSIONS

The functional nerve biomedical system containing the COL/nβ-TCP conduit combined with COL filaments and NGF could promote facial nerve regeneration, thus offering promising potential for clinical applications.