Evaluation of extracellular matrix mimetic laminin bioactive peptide and elastin-like polypeptide

The extracellular matrix (ECM) is comprised of a large network of proteins that are essential for tissue development and repair. A bioactive RGD-containing peptide from laminin α1 chain, A99 (AGTFALRGDNPQG), promotes strong cell attachment and has demonstrated utility in cell culture and tissue engineering. Various materials can be utilized as a scaffold for bioactive peptides; however, it may be advantageous to design materials that use bioconjugation strategies that do not affect bioactivity, generate homogenous products, and can be produced at scale. This report is the first to compare the methods for preparing chemically conjugated and recombinant A99 to elastin-like polypeptides (ELPs) as the scaffold and characterize the biological and cell attachment activity using human dermal fibroblasts (HDFs). ELPs are biocompatible protein-polymers that are also thermo-responsive. Below a lower critical solution temperature (LCST), they are highly soluble. Above the LCST, ELPs phase separate into a polymer-rich liquid, known as a coacervate. Both chemically conjugated and recombinant fusion between A99 and an ELP (A99-ELP-R) show dose-dependent cell attachment. In addition, coating above the LCST provides better cell spreading compared to coating at 4°C. ELPs provide an excellent structural framework for deposition of bioactive peptides of the ECM, and their intrinsic biophysical properties make laminin peptide-ELPs promising biomaterials for cell culture and tissue engineering.