Cell adhesion plays an essential role in cell viability, differentation and motility. The presence of certain biological factors, such as RGD (Arg-Gly-Asp), a tripeptide from the cell-attachment domain, can facilitate cell adhesion to the scaffolds used for tissue engineering. The scaffolds were prepared by electrospinning, a process in which fine fivers with sub-mivron diameters are produced in a high voltage electrostatic field. Novel nanostructured membranes consisting of biodegradable poly (D,L-lactide-co-glycolide) (PLGA) random copolymer and poly (D,L-lactide-co-ethylene glycol) triblock copolymers have been developed by utilizing this electrospinning technology. The non-woven biodegradable nanofiber membrane can be used as an ideal scaffold for tissue regeneration. The goals of this project were to (1) construct an electrospun RGD/copolymer amalgam scaffold and (2) characterize the release properties of RGD from the scaffold. The copolymer solutions much be prepared 24 hours in advance in order for dimethylformamide (DMF), an orgamic solvent, to completely evaporate. RGD was incorporated into the membrane by adding it to the copolymer solution in aqueous form before electrospinning. The release of RGD from 1.5 cm2 sections of the scaffold was assayed in 1x tris-EDTA (TE) biffer. A BCA Protein Assay was utilized to determine the amount of RGD released into the solution. Since RGD is a small molecule and is in the range of 346.4321 Da (Daltons), it should wash from the scaffold quickly, and as a result, only a short term release study was observed. The release profile of RGD from the scaffolds showed release over a study period of 10 days. At 15 minutes, a maximum release percentage of 79% was observed. Future work on the project will concentrate on optimizing and increasing the release of RGD by altering the composition of the scaffold, i.e. changing the quantities of random and block copolymer, as well as assessing the biological integrity of the released RGD by investigating how well RGD will promote cellular adhesion in the MC3T3 cell line, and by using BSA (bovine serum albumin) as a negative control.
Financial support of this work was provided by the Center for Biotechnology at Stony Brook, a National Institutes of Health-SBIR grant (GM63283-02) administered by the Stonybrook Technology and Applied Research, Inc., the SUNY-SPIR program and the U.S. Army Research Office (DAAD190010419).