Reduced medical infection related bacterial strains adhesion on bioactive RGD modified titanium surfaces: A first step toward cell selective surfaces

Abstract

Ideally, implants should inhibit nonspecific protein adsorption, bacterial adhesion, and at the same time, depending on the final application be selective toward cellular adhesion and spreading for all or only selected cell types. Poly(L-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG) polymers have been shown to adsorb from aqueous solution onto negatively charged metal oxide surfaces, reducing protein adsorption as well as fibroblast, osteoblast and epithelial cell adhesion significantly. PLL-g-PEG can be functionalized with bioligands such as RGD (Arg-Gly-Asp), which then restores host cell adhesion, but the surface remains resistant to nonspecific protein adsorption. Previously, it was also shown that both nonfunctionalized PLL-g-PEG and RGD-peptide functionalized PLL-g-PEG reduced the adhesion of Staphylococcus aureus to titanium (Ti) surfaces. The present study looked at the effect of other implant associated infection relevant bacteria, Staphylococcus epidermidis, Streptococcus mutans and Pseudomonas aeruginosa towards the same surface chemistries. The different surfaces were exposed to the bacteria for 1-24 h, and bacteria surface density was evaluated using scanning electron microscopy (SEM) and fluorescence light microscopy (FM). The adhesion of all bacteria strains tested was reduced on Ti surfaces coated with PLL-g-PEG compared to uncoated Ti surfaces even in the presence of RGD. The percentage reduction in bacterial adhesion over the 24-h culture time investigated was 88%-98%, depending on the bacteria type. Therefore, coating surfaces with PLL-g-PEG/PEG-RGD allows cells such as fibroblasts and osteoblasts to attach but not bacteria, resulting in a selective biointeractive pattern that may be useful on medical implants.

Antimicrobial dental implant functionalization strategies —A systematic review

“…For instance, PEG surfaces hinder not only non-specific protein adsorption and bacterial attachment but, to the same degree, the adhesion of mammalian cells. Recent studies have attempted to promote specific binding interactions between host tissues and implant materials by immobilizing bioactive proteins, such as cell adhesive proteins containing arginine-glycine-aspartic acid (RGD) sequences or bone morphogenetic proteins 28,29,98,99,112,163) . Peptide-functionalized polymers exhibit a selective biointeraction pattern that may be useful in dental implantology, as they can enhance attachment of fibroblasts and osteoblasts while reducing non-specific protein adsorption, thus resulting in reduced bacterial adherence.…”

Furanone at Subinhibitory Concentrations Enhances Staphylococcal Biofilm Formation by luxS Repression

“…If bacteria are present, they compete with host cells in a "race for the surface" (15,41). Many approaches have been made to prevent bacterial colonization of surfaces, e.g., by coating with antifouling substances such as poly(L-lysine)-grafted-poly(ethylene glycol) copolymers (PLL-g-PEG) (17,33,42). Bacterial adherence to implant surfaces occurs in two phases (7,32).…”

Multifuctional Nanofilm for Stimulating Bone Cell Attachment, Proliferation and Preventing Bacterial Colonization

“…Only a few papers reported the effects of the adhesive ligand on bacterial adhesion to surface, and it seemed that these RGD-immobilized coating surfaces had no apparent impact on bacterial adhesion [35][36][37][38]. But the intervention of antibacterial/anti-adhesive constituent, such as antimicrobial chitosan [36], and poly(L-lysine)-grafted poly(ethylene glycol) (PLL-g-PEG) [37,38], in the surfaces made these results controversial. For instance, a lower decrease of the adhesion of S. aureus demonstrated on PLL-g-PEG/PEG-RGD surfaces by 69% than that on PLL-g-PEG surface by 89-93%.…”