Peptide-surface modification of poly(caprolactone) with laminin-derived sequences for adipose-derived stem cell...

Human adipose tissue has been recognized as a source of adult stem cells for tissue engineering applications such as bone, cartilage, and soft tissue repair. For the success of these tissue-engineering approaches, a cell delivery vehicle such as a hydrogel or scaffold is required to position the stem cells at the site of need. Surface modification techniques have been instrumental in the development of scaffolds that promote cell-surface interactions. In this study, poly(caprolactone) (PCL), surfaces were modified in order to promote the attachment and proliferation of adipose-derived stem cells (ASCs). RGD, YIGSR, and IKVAV peptide sequences derived from the extracellular matrix protein laminin were each covalently attached to an aminated polymer surface using carbodiimide chemistry. The surface was characterized using scanning electron microscopy (SEM), goniometry and X-ray photoelectron spectroscopy (XPS). The attachment and proliferation of ASCs was assessed on the different peptide-treated surfaces. XPS analysis confirmed the presence of the peptide sequences on the surface of the polymer as indicated by the increase in the nitrogen/carbon ratio on the surface of the polymer. Among all peptide sequences tested, IKVAV-treated surfaces had a significantly greater number of ASCs bound 2 and 3 days after cell seeding. SEM confirmed differences in the morphology of the cells attached to the three peptide-treated surfaces. These results indicate that IKVAV is a suitable peptide sequence for use in surface modification techniques aimed at improving the attachment of ASCs to a tissue-engineered scaffold.