Tuesday, November 6, 2007 - 2:10 PM
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Blending Chitosan With Polycaprolactone: Porous Scaffold Generation And Toxicity

Aparna Sarasam1, Afshan I. Samli2, Linda Hess3, Micheal Ihnat3, and Sundararajan V. Madihally2. (1) Product Development, Med Institute, Incorporated, 1400 Cumberland Avenue, West Lafayette, IN 47906, (2) School of Chemical Engineering, Oklahoma State University, 423 Engineering North, Stillwater, OK 74078, (3) Department of Cell Biology,, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190

In order to address the scarcity of biomaterials that elicit controlled cellular responses in tissue regeneration applications, previously, we showed the possibility of blending chitosan with ƒ'-polycaprolactone (PCL) using a unique solvent of 77% aqueous acetic acid and processing them into membranes. However, chitosan/PCL composite scaffolds formed by controlled rate freezing and lyophilization were physically unstable. The focus of this study was to prepare and characterize porous scaffolds from chitosan-PCL blends. For this purpose, three techniques were explored: i) freeze extraction, ii) freeze gelation, and iii) freeze drying. By freeze-extraction, stable structures were obtained only from PCL, but these were not porous. No stable scaffolds were obtained by freeze-gelation process Stable scaffolds of chitosan/PCL mixtures could not be obtained using 77% acetic acid solvent by any of these techniques. When the solvent composition was changed to 25% aqueous acetic acid, with a small amount of chloroform for dissolution of PCL, stable scaffolds of chitosan/PCL mixtures were obtained by freeze-drying technique. The stability and pore morphology of freeze-dried scaffolds were dependent on the relative mass ratio of chitosan and PCL. Chicken chorioallantoic membranes (CAMs) were wounded and scaffolds were placed in situ to evaluate the cytocompatibility of the blends. Results indicated that in 3D form, chitosan-PCL blends were non-toxic, and also supported the formation of vasculature. In conclusion, these scaffolds show promising potential in tissue engineering applications.