Investigational medications in the treatment of alopecia

Innovative Approaches and Advances for Hair Follicle Regeneration

Pathological hair loss (also known as alopecia) and shortage of hair follicle (HF) donors have posed an urgent requirement for HF regeneration. With the revelation of mechanisms in tissue engineering, the proliferation of HFs in vitro has achieved more promising trust for the treatments of alopecia and other skin impairments. Theoretically, HF organoids have great potential to develop into native HFs and attachments such as sweat glands after transplantation. However, since the rich extracellular matrix (ECM) deficiency, the induction characteristics of skin-derived cells gradually fade away along with their trichogenic capacity after continuous cell passaging in vitro. Therefore, ECM-mimicking support is an essential prelude before HF transplantation is implemented. This review summarizes the status of providing various epidermal and dermal cells with a three-dimensional (3D) scaffold to support the cell homeostasis and better mimic in vivo environments for the sake of HF regeneration. HF-relevant cells including dermal papilla cells (DPCs), hair follicle stem cells (HFSCs), and mesenchymal stem cells (MSCs) are able to be induced to form HF organoids in the vitro culture system. The niche microenvironment simulated by different forms of biomaterial scaffold can offer the cells a network of ordered growth environment to alleviate inductivity loss and promote the expression of functional proteins. The scaffolds often play the role of ECM substrates and bring about epithelial-mesenchymal interaction (EMI) through coculture to ensure the functional preservation of HF cells during in vitro passage. Functional HF organoids can be formed either before or after transplantation into the dermis layer. Here, we review and emphasize the importance of 3D culture in HF regeneration in vitro. Finally, the latest progress in treatment trials and critical analysis of the properties and benefits of different emerging biomaterials for HF regeneration along with the main challenges and prospects of HF regenerative approaches are discussed.

Topical Products for Human Hair Regeneration: A Comparative Study on an Animal Model

Background

Hair loss and hair growth is the subject of tremendous amount of research.

Objective

This study investigated the efficacy of three chemical treatments used in humans for hair loss, using a rat model of hair regrowth. The products tested were 2% minoxidil, Hairgrow (Dar-Al-Dawa Pharma), Aminexil, Dercos (Vichy Laboratoires), and Kerium, Anti-chute (La Roche-Posay).

Methods

Thirty-two adult female Wistar-Bratislava rats were assigned to 4 groups. Two rectangular areas (2×4 cm) were shaved on either sides of the mid dorsal line (left side - control; right side - test area). Group I was treated topically with 2% minoxidil, group II with Aminexil, and group III with Kerium. Each rat received 0.3 ml of substance applied topically to the shaved dorsal skin every day for 28 days. Rats in group IV served as sham controls receiving no treatment. Hair regrowth was evaluated by trichoscopy (with a dermatoscope), grown hair weight (from a surface area of 1 cm²), and histopathological examination for skin thickness, follicle count, and percentage of anagen induction (morphometric assessment).

Results

Treatment with 2% minoxidil significantly induced hair regrowth as assessed by trichoscopy, hair weight examination, and morphometric evaluation. Hair weight examination and morphometric assessment demonstrated the lowest hair growth effect with Aminexil among the tested products. Treatment with Kerium was found to significantly induce hair regrowth (p<0.05 as compared to the control group).

Conclusion

Our study demonstrates that hair regrowth efficacy of products recommended for human use is not similar when tested on an animal model.

Types of hair loss and treatment options, including the novel low-level light therapy and its proposed mechanism

Androgenetic alopecia (AGA) is the most common form of hair loss in men, and female pattern hair loss (FPHL) is the most common form of hair loss in women. Traditional methods of treating hair loss have included minoxidil, finasteride, and surgical transplantation. Currently there is a myriad of new and experimental treatments. In addition, low-level light therapy (LLLT) has recently been approved by the United States Food and Drug Administration (FDA) for the treatment of hair loss. There are several theories and minimal clinical evidence of the safety and efficacy of LLLT, although most experts agree that it is safe. More in vitro studies are necessary to elucidate the mechanism and effectiveness at the cellular level, and more controlled studies are necessary to assess the role of this new treatment in the general population.