(71c) Evaluation of Effective Diffusivity in Porous Scaffolds for Tissue Engineering

Biodegradable porous scaffold used in tissue engineering and regenerative medicine are usually fabricated using natural or synthetic polymers, intact or isolated extracellular matrix (ECM), or a combination of similar materials. The scaffolds are either used in bioreactor systems for in vitro tissue development or surgically implanted at the injury site. The efficacy of the scaffold depends on its ability to meet the metabolic requirements of the cells that populate the scaffold by sufficient gas and nutrient exchange within the surrounding microenvironment of the cells. This study focused on evaluation of effective diffusivity of essential nutrients such as oxygen and glucose in porous scaffold.

Three diffusivity model were selected for evaluation i) Mackie-Meares, ii) Maxwell, and iii) Tortuosity. Diffusivity of glucose and oxygen was calculated using these three models. Diffusivity of glucose in Chitosan-gelatin and PCL scaffolds were experimentally determined using a diffusion chamber apparatus. In addition, experimental diffusivity data for other scaffolds were obtained from literature. The diffusivity models were tested for their diffusivity predictions. The tortuosity model was found to be most suitable among the three models. However, the hydrophilic or hydrophobic nature of the scaffold affects the diffusivity of nutrients. This required further studies to improve diffusivity prediction in porous scaffolds used for tissue engineering