Combining Biologically Active β‑Lactams Integrin Agonists with Poly(l‑lactic acid) Nanofibers: Enhancement of Human Mesenchymal Stem Cell Adhesion

Regulating stem cell adhesion and growth onto functionalized biomaterial scaffolds is an important issue in the field of tissue engineering and regenerative medicine. In this study, new electrospun scaffolds of poly­(l-lactic acid) (PLLA), as bioresorbable polymer, and β-lactam compounds agonists of selected integrins, as functional components with cell adhesive properties, are designed. The new β-lactam-PLLA scaffolds contribute significantly in guiding protein translation involved in human bone marrow mesenchymal stem cells (hBM-MSC) adhesion and integrin gene expression. Scanning electron microscopy, confocal laser scanning microscopy, and Western Blot analyses reveal that GM18-PLLA shows the best results, promoting cell adhesion by significantly driving changes in focal adhesion proteins distribution (β1 integrin and vinculin) and activation (pFAK), with a notable increase of GM18-targets subunits integrin gene expression, α4 and β1. These novel functionalized submicrometric fibrous scaffolds demonstrate, for the first time, the powerful combination of selective β-lactams agonists of integrins with biomimetic scaffolds, suggesting a designed rule that could be suitably applied to tissue repair and regeneration.