One of the major challenges encountered in conventional drug delivery is poor control over proper dosage of the therapeutic agent below toxic concentrations. In wound healing, protective scaffolds loaded with antibacterial agents can be employed to achieve site-specific therapy. Advances in nanotechnology (and especially in graphene-based nanomaterials) allow a high loading ratio of both hydrophilic and hydrophobic drugs, as well as localised thermal release of therapeutics.
A graphene-based wound dressing for localised drug delivery
Undertaken with the support of the Marie Skłodowska-Curie programme, the PANG project developed novel graphene-based nanocomposites and surfaces for the better management of microbial infections. Scientists were particularly interested in applying these novel materials in skin infections, where the exudate covering the wound making it impermeable to topical antibiotics. “By exploiting the photothermal properties of reduced graphene oxide, we developed flexible patches for the highly efficient treatment of wound infections,” explains project coordinator Sabine Szunerits. PANG researchers developed nanofibre mats from reduced graphene oxide containing polyacrylic acid, which allows non-covalent interaction with different antibiotics. These were tested in vitro to assess their ablation ability of bacterial cultures as well as in vivo on superficial skin infections on mice skin. The obtained results are promising and encourage partners to continue with clinical studies. The advantage of such topical graphene dressings compared to classical wound dressings is that heat can be applied locally, limiting side effects on intact skin. In addition, the presence of reduced graphene oxide raises the skin temperature beyond that achieved with an infrared laser alone, facilitating thermal release of antibiotics and at the same time thermally ablating partially the bacteria present. “The reusability of the patch, together with the possibility to sterilise it, renders this method very cost-effective and suitable for skin bandages,” emphasises Szunerits.
PANG impact and future prospects
Tens of thousands of patients die annually in the EU as a result of infections caused by antibiotic-resistant bacteria. The majority of these are caused by Gram-negative pathogens, and they incur billions of euro in healthcare costs. The PANG project proposes a unique biomedical solution that can guarantee the controlled release of drugs over a long period of time. Its use can therefore be expected to extend to treatment of other conditions such as cancer, diabetes and chronic pain. Partners are also investigating the potential of other carbon-based nanostructures, such as nanodiamonds, as vaccine adjuvants to enhance immune responses against particular antigens, while limiting the associated health risks. Indeed, nanostructures are emerging as suitable vehicles for treating viruses. “Virus infections pose a significant health threat due to spreading and their propensity to mutate, as seen in the current COVID-19 pandemic and flu epidemics over the years,” outlines Szunerits. The lack of targeted antiviral therapeutics as well as the constant emergence of new viruses demand novel antiviral agents. PANG partners have recently proposed carbon quantum dots for the treatment of the Middle-East respiratory coronavirus MERS-CoV, and are hoping to extend the approach to the treatment of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
PANG, graphene, wound dressing, antibiotic, drug, drug resistance, antibiotic resistance, graphene nanocomposites, skin infections