Designing topical hyaluronic acid technology-Size does matter…

Hyaluronic acid (HA) plays an important role in cellular and extracellular matrix (ECM) homeostasis. Recent studies demonstrate that low molecular weight (MW) HA has pro-inflammatory characteristics while high MW HA is considered anti-inflammatory and regenerative. In formulating a topical HA product, the possibility of creating a focused high MW HA technology was posed, combining external surface high MW HA constituents with active agents promoting fibroblast production of high MW in the depths of the dermis.

Human dermal fibroblasts and keratinocytes were treated with various agents, and RNA sequencing (RNA-seq) was conducted to identify genes involved in HA synthesis. HA production by fibroblasts was assessed by collecting the culture supernatant, concentrating the protein, and conducting polyacrylamide gel electrophoresis (PAGE). The gel was stained with Stains-All to identify bands relative to known HA products of different MWs. Subsequently, the supernatants were treated with hyaluronidase to confirm the bands corresponded to HA.

The RNA-seq results revealed a variety of agents upregulated HA-related genes. However, a potent upregulation of HA synthesis gene was observed by hexapeptide-11 in the keratinocytes and a newly identified proprietary octapeptide in the fibroblasts. PAGE demonstrated not only robust production of HA by octapeptide, but significantly, the HA produced was ~2 Mega Daltons in size. Octapeptide was the most potent stimulator among the tested agents.

Comprehensive in vitro testing identified a group of active agents that stimulated high MW HA production. This novel approach to HA topical application with exclusively high MW HA production should maximize hydration capacity while encouraging regenerative activity within the ECM. Multi-center trials are underway.