A new noninvasive skin rejuvenation modality shows great promise in achieving thicker, smoother, more elastic skin.
Using a radiofrequency of 13.56 MHz in a vacuum chamber (1x103 Pa), the experimental vacuum radiofrequency plasma device (Mattioli Engineering) ionizes the plasma in the targeted skin to induce a controlled heating of the targeted area, resulting in the activation of dermal fibroblasts and the synthesis of new collagen in one treatment.
Thirty rats were divided into three groups of 10, and areas for treatment and control were chosen on the back of each animal. Each targeted area was treated with a single electric pulse at either low, medium or high intensity, and skin specimens were obtained at two, seven, 30 and 60 days post-treatment.
Collagen synthesis was determined by immuno-histochemistry using a specific anti-procollagen antibody and by trichromic Masson's staining, and cell damage was evaluated by immuno-histochemistry using a specific primary antibody against the heat shock protein HSP90 (an indicator of cell damage).
The effects of different intensities were compared, and evaluations included integrity of epidermis; distribution of collagen and orientation of collagen fibrils to the skin surface; presence of angiogenic blood vessels, inflammatory cells and myofibroblasts; and depth of tissue modifications.
At seven days after one treatment with medium intensity, the activation of dermal fibroblasts and collagen synthesis were higher compared to two days post-treatment. At 30 and 60 days post-treatment, the VRFP-induced effects seen in the treated areas were significantly decreased and eventually returned to a complete normalization of tissue.
The expression of HSP90 was highest at two days after the treatment, but at seven days, the expression began to decrease. At 30 and 60 days, expression was the same as that seen in the untreated, control skin areas.
"Besides an increase in the production of collagen with fibril orientation perpendicular to the skin's surface, the fibroblasts respond to this heat shock by first activating the expression of specific heat shock proteins, which, in turn, induce cell proliferation and differentiation into myofibroblasts, resulting in a smoother, fuller and more elastic skin," says Marco Ruggiero, M.D., Ph.D, department of experimental pathology and oncology, Medical University of Florence, Italy, and head researcher of the study.
According to Dr. Ruggiero, the degree of biological events in the tissue very much depends on the intensity of treatment. Low-intensity therapy only showed a minimal inflammation in the upper layers of the skin, and higher intensity caused severe inflammation and interruption of the epidermis. Medium intensity induced a medium degree of inflammation, stimulating fibroblast proliferation and differentiation and increasing the density and orientation of the collagen components.
When treating scars, skin imperfections or wrinkles, the main goal of therapy is the removal of the old skin and the induction of skin regeneration. Collagen and other dermal structures have their own lifespan, and after a period of time, the cosmetic effect of new collagen fibrils and myofibroblasts is gradually lost.
Human clinical trials are currently under way, and if the results obtained in this study can be reproduced in humans, Dr. Ruggiero envisions that aesthetic treatments using VRFP could be performed a couple of times a year on cosmetic patients.
Disclosure: Dr. Ruggiero's research is supported uniquely by grants of the University of Firenze, Italy. Mattioli Engineering (Italian branch) provided a pre-production model of its "I 2 BEAM" vacuum radiofrequency plasma device.