Development a self crosslink injectable scaffold for GBR/GTR applications

Objective: The objective of this study is to investigate the properties of chitosan/ã-polyglutamic (ã-PGA) based polyelectrolyte complex (PEC) gels and apply to GBR/GTR. Materials and Methods: By utilizing a static mixer tip connected with dual solution tubes comprising (A) solution of chitosan and â-tricalcium phosphate (â-TCP) and (B) solution of ã-PGA, CMC and â-TCP. The mixed chitosan/ã-PGA/CMC/â-TCP solutions could form a gel mass. The measurement of gelling time, gel content, SEM, FT-IR and in vitro degradation were carried out to characterize the injectable scaffold. Gelling time was noted as the time required for the stir bar to stop. Gel content was defined as the ratio of dried specimen weight before and after acetic acid extraction. The morphology was observed by SEM. Interaction between the opposite-charged polymeric was assayed by FT-IR. Results: The extrudate could gel within 1min after injection by a static mixer, and gel content could reach 90%. The lyophilized sample shows interconnected porous structure in SEM result. The FT-IR spectrum shows a broad absorption peak around 3500-3100 cm-1, indicating the enhancement of hydrogen bonding. Moreover, the non-acylated 2-aminoglucose primary amines (1586 cm-1) and –CO- stretching band (1605 and 1428 cm-1) was disappeared, indicating the interaction between the opposite-charged polymeric systems. Conclusions: This gelation property of this PEC system reveals potential applications as an injectable scaffold for GBR/GTR applications.