An innovative method to quantitate tissue integration of hyaluronic acid-based dermal fillers.

BACKGROUND/PURPOSE: Following intradermal injection, hyaluronic acid (HA)-based fillers tend to spread within the reticular dermis and to distribute between the dermal fibers. This biointegration is commonly measured qualitatively using histological methods. We developed a "toolbox" consisting of a visual scoring and a semi-automatic image analysis method using internal developed algorithm to quantitate the biointegration of Restylane® in histological sections. METHODS: Restylane® was injected intradermally in the abdominal skin of 10 healthy human subjects scheduled for abdominoplasty. The injections were performed either in vivo before surgery or ex vivo on samples taken post-surgery at different time points. The samples were processed for histology by visual scoring and image analysis using algorithms developed in Definiens to assess biointegration. RESULTS: The image analysis segmentation was accurate with <5% manual changes. Furthermore, the results calculated with the semi-automatic method were consistent with the visual scores obtained on injected human skin samples by means of a 5-grade photographic scale. A modified hematoxylin-eosin staining was found adequate to visualize both, the filler and the general morphology, on the same section. An excellent correlation was observed between the integration results obtained with PAS/Alcian Blue and HE-stained slides, allowing for a single staining in future studies. CONCLUSION: We developed a modified HE staining histological method and a new histomorphometric image analysis tool to quantitate biointegration of HA-based fillers in human skin. The results obtained in this study confirmed the known intermediate biointegration properties of Restylane®, thus validating these innovative methods.

Application of cosmetic nail varnish does not affect the antifungal efficacy of amorolfine 5% nail lacquer in the treatment of distal subungual toenail onychomycosis: results of a randomised active-controlled study and in vitro assays.

As onychomycosis is unsightly, this study clinically evaluated whether the antifungal efficacy of amorolfine 5% nail lacquer (NL) was affected by a masking, natural-coloured, cosmetic nail varnish applied 24 h later; in vitro investigations were also performed. Subjects with mild-to-moderate distal subungual toenail onychomycosis were randomised to receive amorolfine 5% NL once weekly with or without cosmetic nail varnish applied 24 h later. After 12-week treatment, antifungal activity of affected toenail clippings was assessed by measurement of zones of inhibition (ZOIs) on Trichophyton mentagrophytes seeded agar plates. Mean diameters were 53.5 mm for the amorolfine 5% NL-alone group (n = 23) and 53.6 mm for amorolfine 5% NL plus cosmetic nail varnish group (n = 25). Also, mycological cultures of subungual debris at week 12 were negative for all subjects in both groups. Most subjects (88%) reported that cosmetic nail varnish masked their infected toenails. Additionally, cadaver human nails coated in vitro with or without cosmetic nail varnish 10 min or 24 h post amorolfine NL application all gave ZOIs on Trichophyton rubrum agar plates representing potent antifungal activity. In conclusion, cosmetic nail varnish applied post amorolfine had no effect on the subungual antifungal activity of amorolfine 5% NL or its penetration through toenails.