Antimicrobial peptide lysozyme has the potential to promote mouse hair follicle growth in vitro

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

Lysozyme (Lyz) is an antimicrobial peptide, a safe adjunct, and it has been indicated that Lyz can promote vibrissae follicle growth by enhancing the hair-inductive capacity of dermal papilla cells in mice. The present study produced a new type of minoxidil (Mx)-coated antifungal Lyz-shelled microbubble (LyzMB) for inhibiting bacteria and allergies on the oily scalp. The potential of Mx-coated LyzMBs (Mx-LyzMBs) combined with ultrasound (US) and the role of LyzMB fragments in enhancing hair follicle growth were investigated. Mx grafted with LyzMBs were synthesized and the loading efficiency of Mx on cationic LyzMBs was 20.3%. The biological activity of Lyz in skin was determined using an activity assay kit and immunohistochemistry expression, and the activities in the US+Mx-LyzMBs group were 65.8 and 118.5 μU/mL at 6 and 18 h, respectively. In hair follicle cell culture experiments, the lengths of hair follicle cells were significantly enhanced in the US+Mx-LyzMBs group (108.2 ± 11.6 μm) compared to in the US+LyzMBs+Mx group (44.3 ± 9.8 μm) and the group with Mx alone (79.6 ± 12.0 μm) on day 2 (p < 0.001). During 21 days of treatment in animal experiments, the growth rates at days 10 and 14 in the US+Mx-LyzMBs group increased by 19.4 and 65.7%, respectively, and there were significant differences (p < 0.05) between the US+Mx-LyzMBs group and the other four groups. These findings indicate that 1-MHz US (applied at 3 W/cm², acoustic pressure = 0.266 MPa) for 1 min combined with Mx-LyzMBs can significantly increase more penetration of Mx and LyzMB fragments into skin and enhance hair growth than Mx alone.

Stimulating hair growth via hormesis: Experimental foundations and clinical implications

Numerous agents (approximately 90) are shown to stimulate hair growth in cellular and animal models in a hormetic-like biphasic dose response manner. These hormetic dose responses occur within the framework of direct stimulatory responses as well as in preconditioning experimental protocols. These findings have important implications for experimental and clinical investigations with respect to study design strategies, dose selection and dose spacing along with sample size and statistical power issues. These findings further reflect the general occurrence of hormetic dose responses within the biological and biomedical literature that consistently appear to be independent of biological model, level of biological organization (i.e., cell, organ, and organism), endpoint, inducing agent, potency of the inducing agent, and mechanism.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well-being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet-rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid-nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress-serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs' activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end-point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up-to-date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.

Bottom-up Nanoencapsulation from Single Cells to Tunable and Scalable Cellular Spheroids for Hair Follicle Regeneration

Cell surface engineering technology advances cell therapeutics and tissue engineering by accurate micro/nanoscale control in cell-biomaterial ensembles and cell spheroids formation. By tailoring cell surface, microgels can encapsulate cells for versatile uses. However, microgels are coated in a thick layer to house multiple cells together but not a single cell based. Besides, excessive deposition on cell surface is detrimental to cellular functions. Herein, layer-by-layer (LbL) self-assembly to encapsulate single cell using nanogel is reported, owing to its security and tunable thickness at nanoscale, and further forms cell spheroids by physical cross-linking on nanogel-coated cells for delivery. A hair follicle (HF) regeneration model where the dermal papilla cells (DPCs) are given a 3D installation to maintain its ability of HF induction during in vitro culture is studied. Dermal papilla (DP) spheroids are optimized and that LbL-DPCs aggregation is akin to primary DP is demonstrated. The markers ALP, Versican, and NCAM are examined to investigate that high-passaged (P8) DP spheroids can restore the hair induction potential, which are lost in 2D culture. New HFs are regenerated successfully by implantation of DP spheroids in vivo.

Paclitaxel-loaded star-shaped copolymer nanoparticles for enhanced malignant melanoma chemotherapy against multidrug resistance

Malignant melanoma (MM) is the most dangerous type of skin cancer with annually increasing incidence and death rates. However, chemotherapy for MM is restricted by low topical drug concentration and multidrug resistance. In order to surmount the limitation and to enhance the therapeutic effect on MM, a new nanoformulation of paclitaxel (PTX)-loaded cholic acid (CA)-functionalized star-shaped poly(lactide-co-glycolide) (PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (NPs) (shortly PTX-loaded CA-PLGA-TPGS NPs) was fabricated by a modified method of nanoprecipitation. The particle size, zeta potential, morphology, drug release profile, drug encapsulation efficiency, and loading content of PTX-loaded NPs were detected. As shown by confocal laser scanning, NPs loaded with coumarin-6 were internalized by human melanoma cell line A875. The cellular uptake efficiency of CA-PLGA-TPGS NPs was higher than those of PLGA NPs and PLGA-TPGS NPs. The antitumor effects of PTX-loaded NPs were evaluated by the MTT assay in vitro and by a xenograft tumor model in vivo, demonstrating that star-shaped PTX-loaded CA-PLGA-TPGS NPs were significantly superior to commercial PTX formulation Taxol®. Such drug delivery nanocarriers are potentially applicable to the improvement of clinical MM therapy.

Icariin promotes mouse hair follicle growth by increasing insulin-like growth factor 1 expression in dermal papillary cells

BACKGROUND

Icariin is a major flavonoid isolated from Epimedium spp. leaves (Epimedium Herba), and has multiple pharmacological functions, including anti-angiogenesis, anti-oxidant, anti-inflammatory and immunoprotective effects.

AIM

To investigate whether icariin can stimulate growth of hair follicles in mice and the underlying mechanism.

METHODS

In vitro, the effect of icariin on hair growth was assessed by using a vibrissae hair follicle (VHF) organ-culture model. The proliferation of hair matrix keratinocytes and the expression of insulin-like growth factor (IGF)-1 in follicles were examined by double immunostaining for 5-bromo-2'-deoxyuridine and IGF-1, in the presence or absence of icariin. Dermal papilla cells (DPCs) were cultured and IGF-1 level was measured by reverse transcription-PCR and ELISA after icariin treatment. In vivo, the effect of icariin on hair growth was examined by gavage feeding of icariin to mice whose backs had been depilated, and the conversion of telogen to anagen hair was observed.

RESULTS

Treatment with icariin promoted hair shaft elongation, prolonged the hair cycle growth phase (anagen) in cultured VHFs, and accelerated transition of hair cycle from telogen to anagen phase in the dorsal skin of mice. There was significant proliferation of matrix keratinocytes and an increased level of IGF-1 in cultured VHFs. Moreover, icariin treatment upregulated IGF-1 mRNA expression in DPCs and increased IGF-1 protein content in the conditioned medium of DPCs.

CONCLUSIONS

These results suggest that icariin can promote mouse hair follicle growth via stimulation of IGF-1 expression in DPCs.