Nanostructured Drug Delivery Systems for Targeting 5-α-Reductase Inhibitors to the Hair Follicle

Synergistic treatment of androgenetic alopecia with follicular co-delivery of minoxidil and cedrol in metal-organic frameworks stabilized by covalently cross-linked cyclodextrins

Androgenetic alopecia seriously affects the physical and mental health of patients. The main clinical therapeutic agent, minoxidil tincture, is challenged by solvent irritation and dose-dependent side effects. Our recent work has identified a biosafety natural product, cedrol, that is synergistic in combination with minoxidil, thereby improving medication safety by substantially reducing the clinical dose of minoxidil. In addition, ccross-linked CD-MOF were designed as carriers for hair follicle delivery, and γ-CD in the carriers was cross-linked by diphenyl carbonate with covalent bonds to protect the CD-MOF from rapid disintegration in an aqueous environment. This improved nanocarrier has a drug loading of 25%, whereas nanocarriers increased drug delivery to the hair follicles through ratchet effect, and increased human dermal papilla cells uptake of drugs via endocytosis pathways mainly mediated by lattice proteins, energy-dependent active transport, and lipid raft-dependent, thus improved cell viability, proliferation, and migration, followed by significantly enhancing the anti-androgenetic alopecia effect, with cedrol focusing on inhibiting 5α-reductase and activating Shh/Gli pathway, and minoxidil, which up-regulated VEGF, down-regulated TGF-β, and activated ERK/AKT pathway. This drug combination provides a new therapeutic strategy for androgenetic alopecia, while the newly developed cross-linked CD-MOF has been shown to serve as a promising follicular delivery vehicle.

Methodologies to Evaluate the Hair Follicle-Targeted Drug Delivery Provided by Nanoparticles

Nanotechnology has been investigated for treatments of hair follicle disorders mainly because of the natural accumulation of solid nanoparticles in the follicular openings following a topical application, which provides a drug "targeting effect". Despite the promising results regarding the therapeutic efficacy of topically applied nanoparticles, the literature has often presented controversial results regarding the targeting of hair follicle potential of nanoformulations. A closer look at the published works shows that study parameters such as the type of skin model, skin sections analyzed, employed controls, or even the extraction methodologies differ to a great extent among the studies, producing either unreliable results or precluding comparisons altogether. Hence, the present study proposes to review different skin models and methods for quantitative and qualitative analysis of follicular penetration of nano-entrapped drugs and their influence on the obtained results, as a way of providing more coherent study protocols for the intended application.

Effect of cyclosporine A - Tempol topical gel for the treatment of alopecia and anti-inflammatory disorders

Over the years, extensive research has been carried out to develop new chemical entities for hair loss treatment. Despite these efforts, the newly developed topical and oral treatments have not proven to be curative. Hair loss can result from underlying mechanisms, such as inflammation and apoptosis around hair follicles. We have developed a nanoemulsion based on Pemulen gel for topical application, tentatively addressing both mechanisms. The novel formulation contains two well-known molecules: Cyclosporin A (CsA), an immunosuppressant calcineurin inhibitor, and Tempol, a potent antioxidant. The in vitro permeation study on human skin revealed that the CsA-Tempol gel formulation effectively delivered CsA into the skin's inner target layer, the dermis. The effects of the CsA-Tempol gel on hair regrowth were further demonstrated in the in vivo well-established androgenetic model induced in female C57BL/6 mice. The beneficial outcome was statistically confirmed by quantitative analysis of hair regrowth, weasured by color density. The results were further supported by histology analysis. Our findings revealed a topical synergy effect, resulting in lower therapeutic concentrations of both actives unlikely to cause systemic side effects. Overall, our research suggests that the CsA-Tempol gel is a highly promising platform for treating alopecia.

Pumpkin Seed Oil-Loaded Niosomes for Topical Application: 5α-Reductase Inhibitory, Anti-Inflammatory, and In Vivo Anti-Hair Loss Effects

Pumpkin seed oil (PSO)-loaded niosomes were prepared from Tween 20 and cholesterol by ethanol injection. Confocal microscopy showed better skin permeation and hair follicle accumulation of the niosomes compared to the PSO solution. The PSO-loaded niosomes inhibited 5α-reductase activity in DU-145 cells and hindered IL-6 activity in RAW 264.7 cells. These effects indicated the great potential of PSO-loaded niosomes to reduce hair loss. The hair scalp serum with PSO-loaded niosomes did not show irritation to reconstructed human skin. This formulation presented a significant decrease in the percentage of fallen hairs by 44.42% in the in vivo 60-second hair count experiment and a significant increase in the anagen to telogen (A/T) ratio (1.4-fold) in the TrichoScan^® evaluation after 8 weeks of treatment compared to the initial conditions, indicating the promising efficacy of PSO-loaded niosomes as a natural alternative for anti-hair loss therapy.

Antioxidant and 5α-Reductase Inhibitory Activity of Momordica charantia Extract, and Development and Characterization of Microemulsion

Momordica charantia (M. charantia) is rich in flavonoids, which possess a strong antioxidant capacity and may help prevent hair loss. This study aims to develop the microemulsion of M. charantia with antioxidant activity and 5α-reductase (5aR) inhibitory activity. The total phenolic content (TPC), antioxidant activity, and 5aR inhibitory activity of ethanolic and aqueous extracts of the fruit were investigated. The preparation of M. charantia extract-loaded microemulsion (MELM) was optimized and characterized the MELM. The aqueous extract of M. charantia fruit flesh displayed a TPC of 780.75 ± 24.82 mg Gallic acid equivalence/g of extract. ABTS (2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl), and nitric oxide (NO) radical scavenging activities were observed in all the extracts. About 0.461 ± 0.003 mg finasteride equivalence/g of extract of 5aR inhibitory activity was detected in the aqueous extract of the inner tissue of M. charantia fruit. Based on NO radical scavenging and 5aR inhibitory activity, an aqueous extract of the inner tissue (pericarp with seed) of M. charantia fruit was used to prepare the MELM. The MELM was prepared using a different ratio of tween 80 and ethanol as Smix. The results showed that the 1:1 ratio of tween 80: ethanol produced microemulsion of an optimum size, zeta potential, and polydispersity index. The MELM samples were stored at 5, 30, and 40 °C for 12 weeks, and the stability was assessed. The results revealed that the size, zeta potential, and polydispersity index of the formulated MELM remained unchanged during the investigated time. This study primarily reports the 5aR inhibitory activity of M. charantia extract and the development of microemulsion. The prepared MELM could be further developed into cosmetic or pharmacological preparations to manage hair loss.