IADR Abstract Archives
Evaluation of Chitosan Nanofiber and Collagen GTR Membranes in vivo
Objectives: This study compared two novel chitosan nanofiber membranes to a commercial collagen membrane for guided tissue regeneration in a critical size rat calvarial model.
Methods: Chitosan nanofiber membranes, prepared by electrospinning (5.5% wt/vol chitosan (71% DDA) in 70% trifluoroacetic acid(TFA)-30% methylene chloride, 25 kV), were treated by two methods to remove TFA salts and stabilize nanofiber structure; 1] surface acylation reactions using 50-50 (v/v)% butyric anhydride-pyridine, 2] washing in 10(v/v)% triethylamine then surface reacted with 2.5g/ml tert-butyl dicarbonate. Chitosan discs (15 mm diameter) were punched and ethylene oxide gas sterilized. Collagen discs (15 mm diameter, Biomend Extend, Zimmer, Inc.) were purchased and sterile punched. Specimen (n=1/animal) were implanted to cover 8 mm diameter critical sized defects in male Sprague Dawley rats (250-280g) following University approved IACUC protocol. At 3 and 12 weeks, 5 animals/ implant group were euthanized, x-rayed and tissues analyzed histologically. Blinded sections were scored for inflammation (0-3) by a pathologist.
Results: Defects reamined visible in x-rays at 3 weeks in all groups. At 12 weeks, x-rays showed evidence of bone bridging in all groups. Qualitatively, increased radio-opacity was observed in animals treated with chitosan membranes as compared to collagen membranes, though no difference between chitosan membranes was observed. Histologically, bone forming at edges of defects for all groups was observed at 3 weeks, and evidence of new bone beginning to bridge defect noted for several of the butyric-treated chitosan membranes. Median scores for inflammation at 3 weeks were 1 for both chitosan membranes and 2 for collagen and scores were not statistically different (Chi Sq, p>0.05). Histological analyses for 12 week implants are in progress.
Conclusions: Results thus far suggest that both chitosan membranes are biocompatible and that they support healing of a critical sized defect similar to a commercial collagen membrane.
Methods: Chitosan nanofiber membranes, prepared by electrospinning (5.5% wt/vol chitosan (71% DDA) in 70% trifluoroacetic acid(TFA)-30% methylene chloride, 25 kV), were treated by two methods to remove TFA salts and stabilize nanofiber structure; 1] surface acylation reactions using 50-50 (v/v)% butyric anhydride-pyridine, 2] washing in 10(v/v)% triethylamine then surface reacted with 2.5g/ml tert-butyl dicarbonate. Chitosan discs (15 mm diameter) were punched and ethylene oxide gas sterilized. Collagen discs (15 mm diameter, Biomend Extend, Zimmer, Inc.) were purchased and sterile punched. Specimen (n=1/animal) were implanted to cover 8 mm diameter critical sized defects in male Sprague Dawley rats (250-280g) following University approved IACUC protocol. At 3 and 12 weeks, 5 animals/ implant group were euthanized, x-rayed and tissues analyzed histologically. Blinded sections were scored for inflammation (0-3) by a pathologist.
Results: Defects reamined visible in x-rays at 3 weeks in all groups. At 12 weeks, x-rays showed evidence of bone bridging in all groups. Qualitatively, increased radio-opacity was observed in animals treated with chitosan membranes as compared to collagen membranes, though no difference between chitosan membranes was observed. Histologically, bone forming at edges of defects for all groups was observed at 3 weeks, and evidence of new bone beginning to bridge defect noted for several of the butyric-treated chitosan membranes. Median scores for inflammation at 3 weeks were 1 for both chitosan membranes and 2 for collagen and scores were not statistically different (Chi Sq, p>0.05). Histological analyses for 12 week implants are in progress.
Conclusions: Results thus far suggest that both chitosan membranes are biocompatible and that they support healing of a critical sized defect similar to a commercial collagen membrane.