Plasma-Assisted KR-12 Conjugated PLGA Nanofibers With Dual Osteogenic and Biofilm-Inhibitory Activity

Multidrug-resistant bacterial infections pose a significant challenge in bone tissue engineering, primarily due to the formation of biofilms on implant surfaces, which can impede osteointegration. KR-12, a cationic antimicrobial peptide (AMP) with dual osteoinductive and biofilm-inhibitory properties, represents a promising strategy to address this issue. Poly(lactic-co-glycolic acid) (PLGA) electrospun nanofiber (NF) scaffolds offer biocompatibility, tunable morphology, and support for cell adhesion and proliferation, making them ideal for bone regeneration. While cold atmospheric plasma (CAP) treatment has been explored to enhance peptide functionalization, covalent conjugation of KR-12 to PLGA electrospun NFs has not yet been reported. In this study, KR-12 was incorporated into electrospun PLGA NFs to create a dual-functional scaffold that promotes osteogenic differentiation while inhibiting biofilm formation. Scaffold surface properties were characterized by scanning electron microscopy (SEM) and contact angle measurements, and peptide incorporation was confirmed via fluorescein isothiocyanate (FITC) labeling and FTIR spectroscopy. Human bone marrow-derived mesenchymal stem cells cultured on KR-12-functionalized NFs exhibited enhanced alkaline phosphatase (ALP) activity, calcium and collagen deposition, and upregulated expression of collagen type I (COL1), osteopontin (OPN), and osteocalcin (OCN), as well as positive immunofluorescence staining. Antibacterial and biofilm formation inhibition activities were evaluated against multidrug-resistant MRSA and P. aeruginosa, as well as non-MDR E. coli and S. aureus, demonstrating potent inhibition of biofilm formation. KR-12-functionalized PLGA NFs thus provide a dual-functional platform for infection-resistant bone tissue regeneration, combining osteogenic support with potent inhibition of biofilm formation.