A peptide library approach to biofunctionalized electrospun PLGA scaffolds for tunable endothelial cell responses

Engineering the biomaterial interface is the critical step for directing cell behavior and improving the performance of tissue-engineered scaffolds. This study aimed to establish a systematic interface engineering strategy by functionalizing electrospun scaffolds with a library of peptide motifs and evaluating their biocompatibility as well as dose effects on early cellular responses. Electrospun poly(lactide-co-glycolide) (PLGA) scaffolds with randomly oriented fibers were produced, taking advantage of PLGA’s biocompatibility, mechanical integrity, and reactive end groups that enable surface functionalization. Five cysteine-modified peptides (IKVAV, REDV, GFOGER, (D-Phe)PRP, and KAFDITYVRLKF) were synthesized at high purity and conjugated to maleimide-activated PLGA using thiol coupling. Peptide-enriched scaffolds were systematically assessed and compared for conjugation efficiency, physicochemical and surface properties, cytotoxicity, and biocompatibility in both fibroblast and endothelial cells. Peptide conjugation preserved scaffold morphology and did not measurably affect bulk properties. Cytotoxicity assays indicated that KAFDITYVRLKF may induce toxicity at higher concentrations, underscoring the need to optimize its dose, while IKVAV, REDV, and GFOGER demonstrated favorable biocompatibility. These peptides showed a dose- and time-dependent viability profile for endothelial cells to allow tuning the interface of the biomaterial. GFOGER was found to promote cell proliferation more efficiently than IKVAV and REDV. The inhibitory effect on cell metabolic activity arising from the microenvironment was mitigated in the presence of IKVAV and REDV, suggesting a protective or stabilizing role of the peptide motifs. Collectively, these findings offer a comprehensive investigation of common peptide motifs for selecting and tuning these cues to engineer biointerfaces in next-generation biomaterial designs such as stents, vascular grafts, patches, or dressings.