Yong Miao

Promotional Effect of Platelet‐Rich Plasma on Hair Follicle Reconstitution in vivo

BACKGROUND Platelet‐rich plasma (PRP) containing various growth factors has attracted attention in various medical fields. PRP has recently been used during hair transplantation to increase hair density. OBJECTIVE To investigate the effects of PRP on hair follicle (HF) reconstitution. METHODS AND MATERIALS Freshly isolated epidermal cells and cultured dermal papilla cells (DPCs) were mixed with various concentrations of activated PRP and transferred to a grafting chamber that was implanted onto the dorsal skin of nude mice. The chambers were removed 1 week after grafting, and HF formation was monitored for 4 weeks. RESULTS We observed a significant difference (p < .05) in the number of newly formed follicles in the area of reconstituted skin (344 ± 27 with 10% PRP vs 288 ± 35 without PRP). PRP also shortened the time of hair formation significantly; the first hairs were observed in 18 ± 1 days using 10% PRP, versus 20 ± 1 days without PRP. CONCLUSION A considerable effect of PRP on the time of hair formation and the yield of HF reconstitution was observed in this study. Considering the limited evidence available to judge its efficacy, further studies are required to investigate the mechanism of action of PRP.

Surface Tension Guided Hanging-Drop: Producing Controllable 3D Spheroid of High-Passaged Human Dermal Papilla Cells and Forming Inductive Microtissues for Hair-Follicle Regeneration.

Human dermal papilla (DP) cells have been studied extensively when grown in the conventional monolayer. However, because of great deviation from the real in vivo three-dimensional (3D) environment, these two-dimensional (2D) grown cells tend to lose the hair-inducible capability during passaging. Hence, these 2D caused concerns have motivated the development of novel 3D culture techniques to produce cellular microtissues with suitable mimics. The hanging-drop approach is based on surface tension-based technique and the interaction between surface tension and gravity field that makes a convergence of liquid drops. This study used this technique in a converged drop to form cellular spheroids of dermal papilla cells. It leads to a controllable 3Dspheroid model for scalable fabrication of inductive DP microtissues. The optimal conditions for culturing high-passaged (P8) DP spheroids were determined first. Then, the morphological, histological and functional studies were performed. In addition, expressions of hair-inductive markers including alkaline phosphatase, α-smooth muscle actin and neural cell adhesion molecule were also analyzed by quantitative RT-PCR, immunostaining and immunoblotting. Finally, P8-DP microtissues were coimplanted with newborn mouse epidermal cells (EPCs) into nude mice. Our results indicated that the formation of 3D microtissues not only endowed P8-DP microtissues many similarities to primary DP, but also confer these microtissues an enhanced ability to induce hair-follicle (HF) neogenesis in vivo. This model provides a potential to elucidate the native biology of human DP, and also shows the promising for the controllable and scalable production of inductive DP cells applied in future follicle regeneration.

6-Gingerol Inhibits Hair Shaft Growth in Cultured Human Hair Follicles and Modulates Hair Growth in Mice

Ginger (Zingiber officinale) has been traditionally used to check hair loss and stimulate hair growth in East Asia. Several companies produce shampoo containing an extract of ginger claimed to have anti-hair loss and hair growth promotion properties. However, there is no scientific evidence to back up these claims. This study was undertaken to measure 6-gingerol, the main active component of ginger, on hair shaft elongation in vitro and hair growth in vivo, and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. 6-Gingerol suppressed hair growth in hair follicles in culture and the proliferation of cultured DPCs. The growth inhibition of DPCs by 6-gingerol in vitro may reflect a decrease in the Bcl-2/Bax ratio. Similar results were obtained in vivo. The results of this study showed that 6-gingerol does not have the ability to promote hair growth, on the contrary, can suppress human hair growth via its inhibitory and pro-apoptotic effects on DPCs in vitro, and can cause prolongation of telogen phase in vivo. Thus, 6-gingerol rather than being a hair growth stimulating drug, it is a potential hair growth suppressive drug; i.e. for hair removal.

As a carrier–transporter for hair follicle reconstitution, platelet-rich plasma promotes proliferation and induction of mouse dermal papilla cells

Morphogenesis of hair follicles during development and in hair reconstitution assays involves complex interactions between epithelial cells and dermal papilla cells (DPCs). DPCs may be a source of cells for hair regeneration in alopecia patients. Reconstitution of engineered hair follicles requires in vitro culture of trichogenic cells, a three-dimensional scaffolds, and biomolecular signals. However, DPCs tend to lose their biological activity when cultured as trichogenic cells, and scaffolds currently used for hair follicle regeneration lack biological efficiency and biocompatibility. Platelet-rich plasma (PRP) gel forms a three-dimensional scaffold that can release endogenous growth factors, is mitogenic for a variety of cell types and is used in model tissue repair and regeneration systems. We found that 5% activated PRP significantly enhanced cell proliferation and hair-inductive capability of mouse and human DPCs in vitro and promoted mouse hair follicle formation in vivo. PRP also formed a three-dimensional gel after activation. We used PRP gel as a scaffold to form many de novo hair follicles on a plane surface, showing it to be candidate bioactive scaffold capable of releasing endogenous growth factors for cell-based hair follicle regeneration.

A simple and rapid model for hair-follicle regeneration in the nude mouse.

Methods for hair‐follicle regeneration are important tools for investigating signalling and cytokines during hair‐follicle morphogenesis and cycling. Several animal models for hair reconstitution have been established; however, these models have several shortcomings.

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

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.

Neonatal murine skin-derived cells transplanted using a mini-chamber model produce robust and normal hair

Hair follicle reconstitution models are useful tools for investigating signalling and cytokines during hair follicle morphogenesis and cycling. The chamber model is one of the most established methods available for the study of hair follicle reconstitution and appears to be the most reproducible. However, the chamber model has several deficiencies: infection of skin wounds and subsequent animal death commonly occur, a large number of cells are required and only one chamber can be transplanted onto each animal. We modified these deficiencies by using a mini‐chamber method, which has the advantages of having a high graft take rate, requiring fewer cells and allowing several mini‐chambers to be transplanted onto each animal. In our study, cultured dermal cells at different passages (0 to high) lost the ability to reconstruct hair follicles, but dermal cells cultured overnight (12 h) retained this ability. Using the assay, newborn mice dermal cells that were freshly isolated and cultured overnight (12 h), as well as cultured dermal papilla cells from mice vibrissa follicles, all reconstructed hair follicles. However, cultured dermal papilla cells from human scalp follicles could not reconstruct hair follicles. Copyright

DAPT in the control of human hair follicle stem cell proliferation and differentiation

Introduction Stem cells from hair follicle have great therapeutic applications in regenerative medicine as sources of cells for transplantation. The differentiation pathway selected by hair follicle stem cells (HFSC) is largely determined by local microenvironmental signals. In this study, human hair follicle stem cells were treated with Notch signaling blocker to explore a new approach to modulate human hair follicle stem cell proliferation and differentiation in vitro. Aim To define the functional consequences of blocking the Notch signaling pathway on the proliferation and differentiation of human HSCs. Material and methods The human hair follicle stem cells were treated with various concentrations of Notch signaling blocker DAPT (24-diamino-5-phenylthiazole). The viability of the cells was investigated with clonogenicity assays. The expression of stem cell markers, cell cycle and cell apoptosis were analysed by flow cytometry. Results Notch blocking leads to promotion of human hair follicle stem cell proliferation and inhibition of differentiation in response to DAPT. The maximum effect of DAPT on the viability of human HFSC was observed at a concentration of 20 µM. We found that DAPT treatment results in downregulation of Hes1 and p21 and upregulation of Wnt10b. Conclusions γ-Secretase inhibitor DAPT has a modulatory effect on the human HFSC. The DAPT may modulate human hair follicle stem cell proliferation and differentiation through regulation of p21 and Wnt-10b.

Evaluation Indicators of Aesthetic Effects on Hair Transplantation.

AbstractHair transplantation involves the transplantation of hair, beard, eyebrows, eyelashes, and pubic hair. Based on our experience, the aesthetic result of hair transplantation mainly relies on 4 indicators, including selection of the donor site, direction and angle of grafted hairs, density, and survival rate of implanted hair follicles. We believe that good results can be achieved as long as attention is paid to the above 4 points.

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.