Low-frequency dual-frequency ultrasound-mediated microbubble cavitation for transdermal minoxidil delivery and hair growth enhancement

Abstract

Ultrasound (US) has been found to rejuvenate and invigorate the hair follicles, increase the size of hair shafts, and promote new hair growth. Our present study found that dual-frequency US-mediated microbubble (MB) cavitation significantly enhanced minoxidil (Mx) delivery in both in vitro and in vivo models, while increasing the hair growth efficacy compared to single-frequency US sonication. the in vitro experiments showed that cavitation activity was enhanced more significantly during dual-frequency sonication than single-frequency sonication in higher concentration of MBs. The pigskin penetration depth in the group in which dual-frequency US was combined with MBs was 1.54 and 2.86 times greater than for single-frequency US combined with MBs and in the control group, respectively; the corresponding increases in the release rate of Mx at 18 hours in in vitro Franz-diffusioncell experiments were 24.9% and 43.7%. During 21 days of treatment in C57BL/6J mice experiments, the growth rate at day 11 in the group in which dual-frequency US was combined with MBs increased by 2.07 times compared to single-frequency US combined with MBs. These results indicate that dualfrequency US-mediated MB cavitation can significantly increase both skin permeability and transdermal drug delivery. At the same US power density, hair growth was greater in the group with dual-frequency US plus MBs than in the group with single-frequency US plus MBs, without damaging the skin in mice.

Minoxidil-Coated Lysozyme-Shelled Microbubbes Combined With Ultrasound for the Enhancement of Hair Follicle Growth: Efficacy In Vitro and In Vivo

“…Since the drug delivery enhancement is related to the destruction efficacy of MBs ( Liao et al, 2020a ; Liao et al, 2020b ). As illustrated in Figure 2 , each well of a 24-well plate was filled with about 4 ml of MBs (1.4 × 10 7 , 0.7 × 10 7 , or 0.35 × 10 7 MBs/ml) while ensuring that no air bubbles were trapped when the cover was placed.…”

Management of androgenetic alopecia: a review

“…Moreover, dual-frequency ultrasound sonication improves cavitation activity, which may stimulate neural stem/progenitor cell differentiation and growth factor utilization, while not causing any damage. 33 In a recent study Liao et al, evaluated the assisted minoxidil delivery in mice models showing promising results, this is a new approach and requires further experimentation for safe application in real patients.…”

Transcutaneous application of ultrasound enhances the effects of finasteride in a murine model of androgenic alopecia

“…The present study examined the effects of the application of ultrasound using a murine model of AA under a finasteride regimen. As ultrasound may induce tissue cavitation or temperature elevation (which may increase local blood flow), both of which could confound the interpretation of the results [ 18 ] or have ramifications involving undesired biological effects such as skin injury, premature skin aging, and neuropathic pain [ 19 , 20 ], this study used non-cavitational, low-intensity ultrasound that does not elevate the temperature of the sonicated tissue. The degree of hair growth was evaluated using photographic and histological analyses (hematoxylin and eosin [H&E] staining and β-catenin staining).…”