Mesoporous Magnesium Carbonate Shows Strong Antibacterial Effect

A new study reveals that mesoporous magnesium carbonate (MMC), an alkali earth metal, exerts strong bacteriostatic effect on Staphylococcus epidermidis.

Discovered by researchers at Uppsala University (Sweden), MMC – which is being commercialized as Upsalite though the University spin-out company Disruptive Materials (Uppsala, Sweden) – is a nanomaterial that absorbs more water at low relative humidity better than the best materials previously available, hygroscopic zeolites, thanks to its tunable pore structure. In addition to its ability to absorb a large amount of moisture, MMC has recently been found to be able to stabilize poorly soluble drugs incorporated into the mesopore structure of the material, thus enhancing their dissolution rate.

The material, which consists of amorphous magnesium carbonate and a small portion of crystalline magnesium oxide, is safe to use on skin as it, even at very high concentrations, is nontoxic to human dermal fibroblast cells, and does not induce cutaneous reactions. The researchers also studied the antibacterial effect of MMC, comparing it to mesoporous silica and two other magnesium-containing powder materials as references. The Gram-positive bacterium Staphylococcus epidermidis was used as the model bacterium due to its prevalence on human skin.

Quantification of bacterial viability using a metabolic activity assay (MMA) with resazurin as the fluorescent indicator showed that MMC exerted a strong antibacterial effect on the bacteria, and that alkalinity accounts for the major part of this effect. According to the researchers, the results open up for further development of MMC in on-skin applications, where bacterial growth inhibition without using antibiotics is deemed favorable. The study was published on November 14, 2016, in ACS Omega.

“These newly found bacteriostatic properties, combined with the ability to load and release molecules, for example fragrances from the pores in the material, are highly interesting for many applications,” said Professor Maria Strømme, PhD, of the department of engineering sciences, nanotechnology, and functional materials. “The results open up for development of materials inhibiting bacterial growth without the use of antibiotics for dermal applications.”

Staphylococcus epidermidis is an opportunistic bacterium that that has received recent attention for its involvement in hospital acquired infections (HAIs), and because it can readily become resistant to antibiotics. It is found inside affected acne vulgaris pores, in intravascular devices, and has also been associated with complications in patients with implanted prosthetic material.

Related Links:
Uppsala University
Disruptive Materials