Resistance of bacteria to antibiotics is an urgent problem of humanity, which leads to a lack of therapy for serious bacterial infections. Development of new antibiotics has almost ceased in the last decades-even when a new antibiotic is launched, very soon the resistance of bacteria appears. There is a long list of applications where antimicrobial protection is required to achieve effective treatment. However, if we use the same antibiotics for all these applications, we will remain caught in the "vicious circle" of constant discovery of new synthetic antibiotics and very fast development of their resistantspecies.Therefore,weneedtofindalternativestrategiesthatwillberoutinely usedforsomespecificconditions(wounds,implants,etc.).Thus,wewillkeeptheactivity ofantibioticsandsavethemforacuteconditions(pneumonia,meningitis,etc.).Anoption for designing alternative antimicrobial strategies is to go back to the antimicrobials that were used before the discovery of antibiotics, i.e., inorganic antimicrobial agents includ-

Nanotextured magnesium oxide (MgO) can exhibit both antibacterial and tissue regeneration activity, which makes it very useful for implant protection. To successfully combine these two properties, MgO needs to be processed within an appropriate carrier system that can keep MgO surface available for interactions with cells, slow down the conversion of MgO to the less active hydroxide and control MgO solubility. Here we present new composites with nanotextured MgO microrods embedded in different biodegradable polymer matrixes: poly-lactide-co-glycolide (PLGA), poly-lactide (PLA) and polycaprolactone (PCL). Relative to their hydrophilicity, polarity and degradability, the matrices were able to affect and control the structural and functional properties of the resulting composites in different manners. We found PLGA matrix the most effective in performing this task. The application of the nanotextured 1D morphology and the appropriate balancing of MgO/PLGA interphase interactions with optimal polymer degradation kinetics resulted in superior bactericidal activity of the composites against either planktonic E. coli or sessile S. epidermidis, S. aureus (multidrug resistant-MRSA) and three clinical strains isolated from implant-associated infections (S. aureus, E. coli and P. aeruginosa), while ensuring controllable release of magnesium ions and showing no harmful effects on red blood cells.

No abstract

In this study we designed a multifunctional implant coating by exploiting the properties of V2O5, i.e. the antibacterial activity via myeloperoxidase-like catalytic activity and the bioactivity of low concentrations of vanadate ions.