Reply to comments on “Microneedling with autologous platelet-rich plasma versus microneedling with topical insulin in the treatment of post-acne atrophic scars: A simultaneous split-face comparative study”

Abstract

To the Editor: We read with admiration the comments by Ghanian and Wambier.1Ghanian S. Wambier C.G. Response to “Microneedling with autologous platelet-rich plasma versus microneedling with topical insulin in the treatment of postacne atrophic scars: a simultaneous split-face comparative study”.J Am Acad Dermatol. 2021; 85: e395-e396Abstract Full Text Full Text PDF Scopus (1) Google Scholar Treatment with platelet-rich plasma (PRP) therapy is already an established and proven modality for postacne scars; hence, we thought of comparing the results of microneedling with topical insulin with those of PRP therapy, the benchmark therapy, for postacne scars. We have already admitted the shortcomings of the study in the penultimate paragraph stating “lack of separate assessment of each treatment modality.”2Pawar M. Singh M. Microneedling with autologous platelet-rich plasma versus microneedling with topical insulin in the treatment of postacne atrophic scars: a simultaneous split-face comparative study.J Am Acad Dermatol. 2021; 84: 810-811https://doi.org/10.1016/j.jaad.2020.05.152Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar We agree with the idea of “side randomization”; however, to maintain uniformity in the procedure, we used the same treatment protocol in all the patients. We disagree with the authors' statement that “topical application of protein preparations or growth factors cannot achieve dermal delivery after microneedling,” for which the authors quoted a single case study (which, of course, has the least strength of evidence) and not strong evidence-based study designs, such as randomized controlled trials or systemic meta-analyses. On the contrary, there are various meta-analyses and randomized controlled trials in which researchers demonstrated efficacy of PRP therapy for postacne scars based on histologic evaluation, confirming dermal delivery of growth factors after microneedling.3Long T. Gupta A. Ma S. Hsu S. Platelet-rich plasma in noninvasive procedures for atrophic acne scars: a systematic review and meta-analysis.J Cosmet Dermatol. 2020; 19: 836-844https://doi.org/10.1111/jocd.13331Crossref PubMed Scopus (10) Google Scholar As rightly stated by the authors, the stratum corneum is impermeable to drugs having a molecular weight of more than 500 Da. Hence, the microneedling technique has been developed to overcome this hindrance, and it has been successfully tested in the transdermal delivery of drugs in various pharmacologic categories.4Jin X. Zhu D.D. Chen B.Z. Ashfaq M. Guo X.D. Insulin delivery systems combined with microneedle technology.Adv Drug Deliv Rev. 2018; 127: 119-137https://doi.org/10.1016/j.addr.2018.03.011Crossref PubMed Scopus (126) Google Scholar Interestingly, in recent years, the transdermal delivery of insulin has been largely studied as an alternative to subcutaneous injections for managing diabetes. In fact, microneedling is one of the most studied modalities for generating reversible skin microchannels, improving skin permeability and allowing insulin delivery.4Jin X. Zhu D.D. Chen B.Z. Ashfaq M. Guo X.D. Insulin delivery systems combined with microneedle technology.Adv Drug Deliv Rev. 2018; 127: 119-137https://doi.org/10.1016/j.addr.2018.03.011Crossref PubMed Scopus (126) Google Scholar We failed to find a reference for the authors' statement “after-procedure pressure gradient does not allow dermal delivery liquids to previously made injury columns.” There is a study in which the authors, using confocal laser scanning microscopy, proved that microneedling enhances the delivery of cosmeceutically relevant peptides to the skin.5Mohammed Y.H. Yamada M. Lin L.L. et al.Microneedle enhanced delivery of cosmeceutically relevant peptides in human skin.PLoS One. 2014; 9: e101956https://doi.org/10.1371/journal.pone.0101956Crossref PubMed Scopus (46) Google Scholar As we do not have experience in using the tattoo technique, we cannot comment on its efficacy in the topical application of PRP or insulin. However, we will certainly like to try “drug tattooing” and compare and evaluate its results histologically with those of the microneedling technique in the future. None disclosed. Response to “Microneedling with autologous platelet-rich plasma versus microneedling with topical insulin in the treatment of postacne atrophic scars: A simultaneous split-face comparative study”Journal of the American Academy of DermatologyVol. 85Issue 6PreviewTo the Editor: Drs Pawar and Singh1 presented interesting findings from a split-face study of microneedling followed by the administration of either topical platelet-rich plasma (PRP) or topical fast-acting insulin (40 IU/mL of human insulin and 0.3% metacresol) for the treatment of postacne atrophic scars. The study concluded that microneedling with topical insulin or PRP was associated with statistically significant improvement in postacne atrophic scars.1 The objective of this letter is to express our concerns about the study design, guide future interventional studies, and discuss the mechanisms of action of topical agents. Full-Text PDF