(713h) Porcine Adipose Tissue Derived Scaffold for Soft Tissue Engineering

Scaffolds, 3D porous structures that provide attachment sites and shape growing tissues, are integral to tissue engineering, which aims to address the crucial lack of available immunocompatible tissues for transplantation.  While scaffolds can be synthetic or derived from human or xenogeneic tissues, those derived from natural tissue are predominantly used in clinical applications.  Porcine Adipose Tissue (PAT) is an inexpensive and readably obtained natural tissue source.  Moreover, it is expected that maintaining PAT’s natural tissue morphology will improve nutrient distribution, an important factor during tissue growth.  Two decellularization methods were attempted:  methanol-chloroform submersion, and freeze-thawing.  Methanol-chloroform submersion destroyed the tissue and was discontinued; freeze-thawing was successful and optimized:  the number of freeze-thaw steps (1-7), tissue surface area and thickness, trypsin incubation time (1-3.5 hours), washing time (20-60 minutes), and washing solution were all examined during this process.  Following a failed cell seeding study, a lipid removal strategy, using immersion in xylene, was also devised and optimized (10 seconds to 20 minutes) to remove all lipids and thereby prevent the hydrophobic lipids present from repelling cells suspended in hydrophilic culture media.  Processed scaffold mechanical strength and morphology were examined by micrograph and SEM. Cell seeding was performed again and micrographs examined.  An average elastic modulus of 38.5 kPa and intact morphology, including capillary channels were examined. Cells were examined in micrographs of seeded tissue.  Overall, an optimized decellularization and lipid removal process was developed which retained natural tissue morphology and obtained scaffolds compared favorably with SIS, a clinically available scaffold.