Antimicrobial Polymeric Composites with Embedded Nanotextured Magnesium Oxide

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.

The adsorption and oxidation of SO2 on MgO surface: experimental and DFT calculation studies

The reaction mechanisms and synergistic effects of NO2/O2 on the heterogeneous oxidation of SO2 to sulfate on a MgO surface.

Template method for graphene synthesis

A series of carbon-mineral composites with the carbon content varying from 1.5 to 12.2 wt.% was synthesized by MgO carbonization in 1,3-butadiene at 600 oC. The synthesized carbon-mineral composites were studied by EPR, XRD and transmission electron microscopy. It was shown by EPR that the MgO surface was completely covered with carbon after depositing 8-10 wt.% C. MgO from the composite was dissolved by treatment in hydrochloric acid. The surface area of the carbon samples obtained after the acid treatment was studied by thermal desorption of argon. It was shown that the synthesized carbon material consisted of several graphene layers. Specific surface area of the synthesized graphene had a maximum about 1800-1900 m2/g for samples obtained from C-MgO composites containing 8-10 wt.% C.