Beyond the substantial financial costs associated with chronic wounds (estimated to be between $28-96 billion dollars in Medicare costs in 2018; Nussbaum et al., 2018), the subsequent chronic inflammation and disability arising from such wounds are significant exacerbating factors that limit health-span in older adults. A recent study from a multidisciplinary wound center demonstrated that frailty prevalence, using the deficit accumulation model, was approximately 75% among their patients and wound healing rate was slower in frail individuals (Espaulella-Ferrer et al., 2021). Wound center clinic visits to manage chronic wounds outside of the hospital setting can also be burdensome given the need for transportation and frequency of visits. Older adults may also have difficulty in mobility or vision impairment that can make home wound care challenging. There remains a great need for novel wound care products that can both expedite healing time and that do not require a complex regimen.
Our study, published in the November/December issue of Wound Repair and Regeneration, seeks to address these concerns (Nidadavolu et al., 2021). Previous work from our group showed that the commonly used blood pressure drug valsartan, which is an inhibitor of the renin-angiotensin system, can significantly increase wound healing in a diabetic pig model when reformulated into a topical cream and applied daily (Abadir et al., 2018). Using nanotechnology, our team has developed valsartan nanofilaments – in other words, nanoscale thread-like structures of valsartan -- that self-assemble into a hydrogel. This biodegradable hydrogel allows for long-term and localized release of valsartan directly into the wound bed.
We have tested wound healing with our valsartan nanofilaments in diabetic rat wounds, another frequently used animal model of wound healing. The diabetic rats treated with valsartan nanofilaments demonstrated significantly faster wound healing compared to the placebo group and we observed beneficial changes in critical wound healing-associated cell signaling pathways and mitochondrial energy utilization as illustrated in the figure. This work is an important first step in demonstrating the clinical efficacy of a valsartan hydrogel for faster, more efficient treatment of diabetic wounds. As we prepare for clinical trials, we are excited by the possibilities of using nanotechnology-based drug delivery to improve physical function in frail adults with chronic wounds. Additionally, future studies can examine if pre-treatment of areas at high risk of skin breakdown with valsartan nanofilament hydrogel can prevent the development of diabetic-related wounds in frail adults.