Responsive,
theranostic nanosystems, capable of both signaling and treating
wound infections, is a sophisticated approach to reduce the most common and potentially traumatizing side effects of
burn wound treatment: slowed wound healing due to prophylactic anti-infective
drug exposure as well as frequent painful dressing changes. Antimicrobials as well as
dye molecules have been incorporated into biodegradable nanosystems that release their content only in the presence of pathogens. Following nanocarrier degradation by bacterial
enzymes, any
infection will thus emit a visible signal and be effectively treated at its source. In this study, we investigated the effect of fluorescent-labeled
hyaluronan nanocapsules containing
polyhexanide biguanide and
poly-L-lactic acid nanoparticles loaded with
octenidine on primary human dermal microvascular endothelial cells, which play a major role in cutaneous wound healing. Microscopic and flow cytometric analysis indicated a time-dependent uptake of both the
nanocapsules and the nanoparticles. However,
enzyme immunoassays showed no significant influence on the expression of pro-inflammatory
cell adhesion molecules and
cytokines by the endothelial cells. Under angiogenic-stimulating conditions, the potential to form capillary-like structures in co-culture with dermal fibroblasts was not inhibited. Furthermore, cytotoxicity studies (the MTS and
crystal violet assay) after short- and long-term exposure to the materials demonstrated that both systems exhibited less toxicity than solutions of the
antiseptic agents alone in comparable concentrations. The results indicate that responsive antimicrobial nanocomposites could be used as an advanced drug delivery system and a promising addition to current best practice
wound infection prophylaxis with few side effects.