Characteristics and biocompatibility of a biodegradable genipin-cross-linked gelatin/β-tricalcium phosphate reinforced nerve guide conduit.
ABSTRACT To modulate the mechanical properties of nerve guide conduit for surgical manipulation, this study develops a biodegradable composite containing genipin cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles as a nerve guide material. The conduit was dark bluish and round with a rough and compact outer surface compared to the genipin cross-linked gelatin conduit (without β-tricalcium phosphate). Water uptake and swelling tests indicate that the conduit noticeably increases the stability in water, and the hydrated conduit does not collapse and stenose. The conduit has a sufficiently high level of mechanical properties to serve as a nerve guide. After subcutaneous implantation on the dorsal side of a rat, the degraded conduit only evokes a mild tissue response, and the formation of a very thin fibrous capsule surrounds the conduit. This paper assesses the effectiveness of the conduit as a guidance channel when we use it to repair a 10 mm gap in the rat's sciatic nerve. The experimental results show no gross inflammatory reactions of the peripheral nerve tissues at the implantation site in either group. In overall gross examination, the diameter of the intratubular and newly formed nerve fibers in the conduits exceeds that of the silicone tubes during the implantation period. The quantitative results indicate the superiority of the conduits over the silicone tubes. This study microscopically observes the nerve regeneration in the tissue section at the middle region of all implanted conduits. Therefore, the histomorphometric assessment demonstrates that the conduit could be a candidate for peripheral nerve repair.
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ABSTRACT: This study used a biodegradable composite containing genipin-cross-linked gelatin annexed with β-tricalcium phosphate ceramic particles (genipin-gelatin-tricalcium phosphate, GGT), developed in a previous study, as a nerve guide conduit. The aim of this study was to analyse the influence of a large-area irradiated aluminium-gallium-indium phosphide (AlGaInP) diode laser (660 nm) on the neural regeneration of the transected sciatic nerve after bridging the GGT nerve guide conduit in rats. The animals were divided into two groups: group 1 comprised sham-irradiated controls and group 2 rats underwent low-level laser (LLL) therapy. A compact multi-cluster laser system with 20 AlGaInP laser diodes (output power, 50mW) was applied transcutaneously to the injured peripheral nerve immediately after closing the wound, which was repeated daily for 5 min for 21 consecutive days. Eight weeks after implantation, walking track analysis showed a significantly higher sciatic function index (SFI) score (P<0.05) and better toe spreading development in the laser-treated group than in the sham-irradiated control group. For electrophysiological measurement, both the mean peak amplitude and nerve conduction velocity of compound muscle action potentials (CMAPs) were higher in the laser-treated group than in the sham-irradiated group. The two groups were found to be significantly different during the experimental period (P<0.005). Histomorphometric assessments revealed that the qualitative observation and quantitative analysis of the regenerated nerve tissue in the laser-treated group were superior to those of the sham-irradiated group. Thus, the motor functional, electrophysiologic and histomorphometric assessments demonstrate that LLL therapy can accelerate neural repair of the corresponding transected peripheral nerve after bridging the GGT nerve guide conduit in rats.Injury 03/2011; 42(8):803-13. · 2.46 Impact Factor
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ABSTRACT: This study proposes a biodegradable nerve conduit comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin annexed with β-tricalcium phosphate (β-TCP) ceramic particles (EDC-gelatin-TCP, EGT). For this study, the EGT-implant site in rats was irradiated using 660-nm GaAlAsP laser diodes (50 mW) for trigger point therapy to investigate the use of low-level laser (LLL) stimulation in the regeneration of a 15-mm transected sciatic nerve. Animals were divided into three groups: a control group undergoing autologous nerve graft (autograft); a sham-irradiated group (EGT), and an experimental group undergoing laser stimulation (EGT/LS). Two trigger points on the surgical incision along the sciatic nerve were irradiated transcutaneously for 2 min daily for 10 consecutive days. Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (SFI; p < 0.05) and improved toe spreading development in the autograft and EGT/LS groups, compared to the EGT group. In the electrophysiological measurement, the mean recovery index (peak amplitude and area) of the compound muscle action potential curves in the autograft and EGT/LS groups showed significantly improved functional recovery than in the EGT group (p < 0.05). Compared with the EGT group, the autograft and EGT/LS groups showed a reduction in muscular atrophy. Histomorphometric assessments showed that the EGT/LS group had undergone more rapid nerve regeneration than the EGT group. Therefore, motor function, electrophysiological reaction, muscular reinnervation, and histomorphometric assessments demonstrate that LLL therapy can accelerate the repair of a 15-mm transected peripheral nerve in rats after being bridged with the EGT nerve conduit. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.Journal of Biomedical Materials Research Part A 02/2013; · 2.83 Impact Factor
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ABSTRACT: This study proposes a biodegradable nerve conduit containing genipin-cross-linked gelatin annexed with tricalcium phosphate ceramic particles (genipin-gelatin-tricalcium phosphate, GGT) in peripheral nerve regeneration. Firstly, cytotoxicity tests revealed that the GGT-extracts were not toxic, and promoted the proliferation and neuronal differentiation of adipose tissue-derived stem cells (ADSCs). Secondly, the GGT composite film effectively supported ADSCs attachment and growth. Additionally, the GGT substrate was biocompatible with the neonatal rat sciatic nerve and produced a beneficial effect on peripheral nerve repair through in vitro tissue culture. Finally, the experiments in this study confirmed the effectiveness of a GGT/ADSCs nerve conduit as a guidance channel for repairing a 10-mm gap in a rat sciatic nerve. Eight weeks after implantation, the mean recovery index of compound muscle action potentials (CMAPs) was significantly different between the GGT/ADSCs and autografts groups (p < 0.05), both of which were significantly superior to the GGT group (p < 0.05). Furthermore, walking track analysis also showed a significantly higher sciatic function index (SFI) score (p < 0.05) and better toe spreading development in the GGT/ADSCs group than in the autograft group. Histological observations and immunohistochemistry revealed that the morphology and distribution patterns of nerve fibers in the GGT/ADSCs nerve conduits were similar to those of the autografts. The GGT nerve conduit offers a better scaffold for the incorporation of seeding undifferentiated ADSCs, and opens a new avenue to replace autologous nerve grafts for the rapid regeneration of damaged peripheral nerve tissues and an improved approach to patient care.Journal of Biomedical Materials Research Part A 01/2012; 100(1):48-63. · 2.83 Impact Factor