A novel antibacterial compound decreases MRSA biofilm formation without the use of antibiotics in a murine model.

Despite significant advancements in material science, surgical site infection (SSI) rates remain high and prevention is key. This study aimed to demonstrate the in vivo safety and antibacterial efficacy of titanium implants treated with a novel broad-spectrum biocidal compound (DBG21) against methicillin-resistant Staphylococcus aureus (MRSA). Titanium (Ti) discs were covalently bound with DBG21. Untreated Ti discs were used as controls. All discs were implanted either untreated for 44 control mice or DBG21-treated for 44 treated mice. After implantation, 1 × 107 colony forming units (CFU) of MRSA were injected into the operating site. Mice were killed at 7 and 14 days to determine the number of adherent bacteria (biofilm) on implants and in the peri-implant surrounding tissues. Systemic and local toxicity were assessed. At both 7 and 14 days, DBG21-treated implants yielded a significant decrease in MRSA biofilm (3.6 median log10 CFU [99.97%] reduction [p < 0.001] and 1.9 median log10 CFU [98.7%] reduction [p = 0.037], respectively) and peri-implant surrounding tissues (2.7 median log10 CFU/g [99.8%] reduction [p < 0.001] and 5.6 median log10 CFU/g [99.9997%] reduction [p < 0.001], respectively). There were no significant differences between control and treated mice in terms of systemic and local toxicity. DBG-21 demonstrated a significant decrease in the number of biofilm bacteria without associated toxicity in a small animal implant model of SSI. Preventing biofilm formation has been recognized as a key element of preventing implant-related infections.

Covalent immobilization of active lysozyme on Si/glass surface using alkoxy Fischer carbene complex on SAM.

A cross-metathesis reaction between an alkene terminated self-assembled monolayer (SAM) on glass/Si wafer and an alkene tethered Fischer carbene complex yielded a functionalized surface. Rapid aminolysis of the Fischer carbene moieties permit efficient anchoring of amine containing molecules on such a surface. Attachment of 1-pyrenemethylamine was thus monitored by ATR-IR spectroscopy and fluorescence microscopy. Similarly, BSA and lysozyme were individually grafted to such Fischer carbene modified surfaces using their pendant lysine residues. It has been demonstrated that the anchored lysozyme retains its bactericidal property.

Engineering bioactive surfaces with Fischer carbene complex: protein A on self-assembled monolayer for antibody sensing.

A Fischer carbene complex was grafted onto self-assembled monolayers (SAMs) on gold or glass by a copper-free "click" reaction. Pendant lysine residues of protein A obtained from Staphylococcus aureus rapidly reacted with the electrophilic metal complex on SAM effecting a covalent attachment of protein A with the surface. The protein A coated surface further led to bioaffinity immobilization of rabbit IgG in an oriented manner, a feature that also permits its purification from rabbit serum. Rabbit IgG could be removed from protein A coated surface by pH adjustment. The regenerated protein A surface was reused three times without loss of activity.

A new bio-active surface for protein immobilisation via copper-free 'click' between azido SAM and alkynyl Fischer carbene complex.

Fischer carbene complex anchored on glass or silicon surface using a Cu-free 'click' reaction allows facile and swift covalent grafting of protein molecules like Bovine Serum Albumin (BSA).

A new, simple approach to confer permanent antimicrobial properties to hydroxylated surfaces by surface functionalization.

A new, simple method to obtain ultrathin polycationic monolayers on hydroxylated surfaces is described which uses a bifunctional copolymer comprising a reactive part (trimethoxysilane) and positive charges (quaternary ammonium salts) to confer antimicrobial properties.