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Abstract Numerous methods are available today to rejuvenate the skin, such as laser resurfacing and deep peeling. However, these treatments are ablative and rejuvenate the skin while destroying the epidermis and, very importantly, its basement membrane. Since the introduction of ”microneedling therapy ”in 1997, it has evolved into a simple and fast method for safely treating wrinkles and scars and producing smoothness. As opposed to ablative laser treatments, the epidermis remains intact and is not damaged. For this reason, the procedure can be repeated safely and is also suited to regions where laser treatments and deep peels cannot be performed. The technique involves puncturing the skin multiple times with a small needle to induce collagen growth. The needle breaks old collagen strands in the most superficial layer of the dermis that tether scars or wrinkles. It is presumed that this process promotes removal of damaged collagen growth and induces more collagen immediately under the epidermis. Because it is non ablative, microneedling therapy can be performed safely on all skin types and, very importantly, without the risk of dyspigmentation Matrix metalloproteinases are a large family of calcium-dependent zinc-containing endopeptidases involved in normal and pathological events in almost all human tissues. MMP-1, MMP-3, and MMP-9 are primary UV-inducible collagenolytic enzymes, and MMP-1 is the major protease capable of initiating the degradation of native fibrillar collagens in human skin in vivo. In the present study, we hypothesized that the level of MMP-1 and MMP-9 would decrease after skin rejuvenation using microneedling therapy. Consequently, this study aimed at investigating this hypothesis by studying the effect induced by skin microneedling (by using Dermaroller) of aged skin through immune-histochemical assessment of tissue expression of MMP-1 and MMP-9 before and after microneedling. Ten female subjects aged 36 to 50 years with clinical signs of skin aging were subjected to two microneedling sessions, 4 weeks apart for face rejuvenation. They have Fitzpatrick skin types III or IV and followed types I and II Glogau’s photoaging classification. Efficacy was assessed using clinical assessment of facial skin. Cutaneous remodeling was assessed by histological analyses of tissues that were stained by H&E, as well as by immune-histochemical expression of MMP-1 and MMP-9. Skin biopsies were obtained from the treatment area at baseline, and 4 weeks after the second treatment session. This study revealed that skin microneedling resulted in significant clinical improvement in the appearance of wrinkles and uneven skin pigmentation. Regarding the histopathologic evaluation, the post-treatment specimens revealed an increase in epidermal thickness and marked improvement in the rete ridges pattern and these findings are suggestive of re-epithiliztion after dermaroller micro-holes and are reflected and perceived clinically as an improved texture of skin after needling session. In addition, significant neocollagenesis was observed with increased collagen thickness throughout the dermis. The newly formed collagen fibers had a uniform distribution following a parallel axis to the surface of the epidermis, involving the superficial, mid and deep reticular dermis. Our study revealed that skin microneedling resulted in a significant reduction in MMP-1 and MMP-9 expression after microneedling. To our knowledge, no previous reported studies on the effect of skin microneedling on MMP expression could be addressed in the literature. As regard the age of the study cases, it was observed that MMP-1 and MMP-9 expression showed a highly significant increase with age. Interestingly, there was a highly significant decrease in MMP-1 expression with older age after skin microneedling. Although there was no statistically significant difference between type III and type IV skin photo-type cases as regard the expression of both MMP-1 and MMP-9 in our study, however, we noticed that the expression of both MMP-1 and MMP-9 was increased in type III Fitzpatrick skin photo- type cases more than type IV photo-type cases. To our knowledge, no previous studies have been done to compare the expression of various MMPs in different Fitzpatrick skin photo-types. Remarkably, there was a higher expression of MMP-1 and MMP-9 in cases with type II Glogau’s classification than in cases with type I Glogau’s classification before and after microneedling therapy. These results again denoted progressive increase in MMP-1 and MMP-9 expression with progressive aging and collagen destruction as reflected by Glogau’s classification. As far as our acquaintance, no previous reports correlated MMP expression level exactly with types of Glogau’s classification. We concluded from the current study that skin microneedling by Dermaroller might be an effective and tolerable treatment in facial rejuvenation of aged skin as shown by clinical evaluation, routine H&E histopathological examination and immunohistochemical study of MMP-1 and MMP-9. |