Resumen

Objectives: 1. Know principles of laser-assisted hyaluronic acid delivery. 2. Comprehend morphologic and metabolic changes with laser-assisted HA delivery. 3. Understand benefits and limits of multiphoton tomography for LADD monitoring. Introduction: Laser-assisted drug delivery (LADD) is a treatment method to enhance the penetration of pharmaceuticals to and through the skin. In recent years, laser-assisted delivery of cross-linked HA gels has gained enormously in popularity, but our current understanding is mostly limited to clinical assessments. The aim of the present study is to track and monitor hyaluronic acid (HA) and analyze its effect on human skin in vivo after ablative fractional laser (AFL) treatment. Materials / method: Healthy male and female subjects were recruited. Four areas were marked on their forearms and each area was assigned to either (i) AFL + HA, (ii) AFL monotherapy, (iii) topical HA monotherapy, or (iv) untreated control. A carbon dioxide laser was used for the AFL treatment. Follow-up measurements were scheduled 30 minutes and 30 days after treatment using multiphoton tomography equipped with fluorescence lifetime imaging (MPT-FLIM). Results: 11 subjects were recruited. By detecting fluorescence lifetimes, HA gel and the anesthetic ointment could be distinguished from the surrounding tissue. Following AFL treatment, HA gel was detectable throughout all epidermal and upper dermal layers. In contrast, in intact skin, HA gel was only found in the superficial layers, and the levels were noticeably lower. The cellular mean fluorescence lifetime calculations suggested that the HA gel used had advantageous attributes for supporting the wound healing process following laser treatment. Conclusion: LADD has demonstrated its effectiveness in enhancing HA uptake into the skin, allowing for improved hydration and skin rejuvenation over time. Additionally, LADD may be a beneficial treatment option in laser resurfacing treatments. MPT-FLIM has shown to be an appropriate diagnostic tool for monitoring drug delivery and assessing treatment responses, enabling personalized therapy adjustment.