Retinaldehyde/hyaluronic acid fragments: a synergistic association for the management of skin aging

Abstract

This clinical study showed the efficacy and value of the RAL-HAFi combination in the management of aging skin in a large cohort of patients.

Hyaluronan-Phosphatidylethanolamine Polymers Form Pericellular Coats on Keratinocytes and Promote Basal Keratinocyte Proliferation

“…Topical application of unmodified HA to intact skin in situ penetrated into the epidermis and dermis as previously reported [42, 69–71] but this was limited compared to HA-PE polymers. In addition, most of the unmodified HA remained associated with the stratum corneum and was not retained in skin as long as HA-PE.…”

“…Transepidermal or dermal HA delivery modalities, although promising, have similarly failed to reliably replenish sustained high levels of native HMW HA in the epidermis or dermis of aged skin [66–68]. This failure is likely because of poor penetration of topically applied HA formulations of MW greater than 50 KDa [39, 69–71], reduced HA capture in the epidermis as a result of declining CD44 levels [4, 42, 72] and aberrant organization as well as rapid clearance of the exogenous HA formulations [40, 60]. …”

Efficacy and safety of retinaldehyde 0.1% and 0.05% creams used to treat photoaged skin: A randomized double‐blind controlled trial

“…Photoaged skin is characterized by both fine wrinkling and coarse wrinkling, a rough texture, a sallow color, and uneven pigmentation associated with a reduction in microcirculation, elastosis, cellular atypia, preneoplastic dysplasia, and epidermal atrophy . Topical retinoids reverse some aspects of skin aging induced by excessive sun exposure . Retinoids define a class of substances that are natural or synthetic vitamin A (retinol) derivatives .…”

“…Topical retinoids reverse some aspects of skin aging induced by excessive sun exposure . Retinoids define a class of substances that are natural or synthetic vitamin A (retinol) derivatives . The retinoid family comprises vitamin A (retinol) and its natural derivatives such as retinaldehyde (RAL) and retinoic acid.…”

“…Retinol is oxidized to retinoic acid in two steps: Retinol is reversibly oxidized by retinol dehydrogenase to give RAL, and then, RAL is irreversibly oxidized by RAL dehydrogenase to give retinoic acid, the most potent form of all vitamin A derivatives (Figure ) . Then, retinoic acid is widely used to this end, but topical application irritates the skin . RAL is the natural precursor of retinoic acid, and the skin metabolism thereof has been extensively studied .…”