Cell & Stem Cell Research

Biography

Biography: Caroline Hoemann

Abstract

In periodontal bone reconstruction procedures, bone growth is enhanced by osteogenic factors and impaired by wound infection. PepGen P-15 (P15) is an osteogenic collagen-mimetic peptide, and competence stimulating peptide (CSP) is a cationic amphiphilic peptide with antimicrobial activity. This study analyzed whether surfaces coated with P15-CSP fusion peptide have dual anti-infective and pro-osteogenic activities in vitro. Plastic surfaces were dry-coated with or without P15-CSP, CSP, P15, or left uncoated, then inoculated with Streptococcus mutans or seeded with human mesenchymal stem cells (MSCs). CSP coatings inhibited S. mutans planktonic growth while P15-CSP coatings suppressed biofilm formation. P15 had no antimicrobial or anti-biofilm activity. MSCs adhered and spread more rapidly on P15-CSP and CSP coatings compared to P15-coated and uncoated culture wells, although CSP-coatings showed slight cytotoxicity to MSCs after 24 hours of culture. After 3 weeks in osteogenic culture, MSCs up-regulated alkaline phosphatase activity on tissue culture plastic and P15, CSP and P15-CSP coatings, with a selectively higher matrix mineralization on P15-CSP-coated surfaces (p<0.05). In other assays, peptides were adsorbed to surfaces pre-coated with thin films of plasma-polymerized hydrophilic carboxylated ethylene (L-PPE:O) or hydrophobic hexamethyl disiloxane HMDSO. MSCs expressed alkaline phosphatase activity on carboxylated surfaces with higher matrix calcificationwhen L-PPE:O was further coated with P15 or P15-CSP. Unexpectedly, MSCs cultured on hydrophobic thin films developed alkaline phosphatase activity and failed to calcify, with or without peptide coatings. This study revealed that P15-CSP coatings stabilized by electrostatic interactions exert dual properties of anti-biofilm activity, and accelerated MSC adhesion and end-stage osteogenic differentiation.