Engineering the Niche for Hair Regeneration: A Critical Review

This study observed that dermal papilla cell aggregates showed increased viability and gene expression on softer 3D substrates, indicating the importance of substrate stiffness in cellular behavior.

This study demonstrated a method for large-scale preparation of self-sorted hair follicle germs in vitro, which successfully generated hair follicles when transplanted into the skin of nude mice.

This review discusses the various components essential for successful tissue engineering, such as cell sources, modification methods, and supportive matrices, and highlights the need for functional synergy without reporting new experimental results.

This study found that Blimp1 plays a key role in promoting hair follicle morphogenesis and growth by mediating inductive signaling pathways in dermal papilla cells.

This review highlights recent advancements in microfluidics for 3D tissue model generation and discusses its applications in tissue engineering and high-throughput drug screening without reporting new experimental results.

In this study, researchers differentiated induced pluripotent stem cells into cells with dermal papilla-like properties, demonstrating their potential role in hair follicle bioengineering and drug testing for hair growth.

This study developed a new protocol to efficiently produce skin dermal stem cells from human induced pluripotent stem cells, which may aid in treating various skin disorders.

In this study, researchers developed thermoresponsive nanogels that effectively penetrate hair follicles and release a model drug when triggered by temperature, demonstrating greater penetration for medium to large nanogels (300–500 nm) compared to smaller ones.

This study found that hair follicles can be used to generate pluripotent stem cells, which successfully differentiate into keratinocytes and may improve hair regeneration and grafting for medical applications.

This study found that dexamethasone-loaded Eudragit® L 100 nanoparticles displayed controlled drug release depending on pH levels, with minimal toxicity to human fibroblasts.

In this study, the RADA-PRG hydrogel enhanced SKP proliferation, survival, and gene expression, effectively supporting hair follicle regeneration in mice.

This protocol describes a method for regenerating hair follicles using a bioengineering technique called the Organ Germ Method, but it reports no new clinical results.

This study found that using layer-by-layer encapsulation techniques on dermal papilla cells can support their function and may help treat hair loss when used in conjunction with freshly isolated epidermal cells.

This review discusses the biology of hair follicles and mechanisms behind various hair disorders, but it presents no new findings; the authors emphasize understanding these concepts to inform treatment development.

This review discusses current knowledge on the biological mechanisms of different types of alopecia but reports no new clinical findings; the authors highlight future research directions, especially regarding epidermal stem cells and immune pathways.

In this study, polymeric micelles containing retinoic acid were found to improve targeted delivery to hair follicle structures in human skin more efficiently than a marketed retinoic acid gel, suggesting potentially safer and more effective acne treatment.

This study found that a 3D Matrigel culture technique for dermal papilla cell spheroids can enhance hair follicle inductivity and induce hair-like fiber differentiation in vitro, even with high-passage cells.

This study found that human dermal papilla cells reprogram into induced pluripotent stem cells with higher efficiency than dermal fibroblasts, demonstrating their potential as an alternative source for iPS cells.

In this study, researchers developed a method to differentiate human iPSCs into cells that can generate all lineages of hair follicles, potentially aiding treatments for hair loss and skin disorders.

This study found that low-level laser treatment with the HairMax Lasercomb significantly increased terminal hair density in both men and women with pattern hair loss, with no serious adverse events reported.

This review examines the literature on the molecular and cellular makeup of the hair follicle niche and how it influences stem cell behavior during hair regeneration, but does not provide new experimental results.

This research reported that squarticles, nanoparticles made from sebum-derived lipids, enhanced the follicular delivery and skin accumulation of diphencyprone and minoxidil, indicating effective drug deposition with reduced systemic absorption in alopecia treatment.

This study found that altering cell culture conditions to form three-dimensional papilla spheroids can restore the ability of human dermal papilla cells to induce hair growth in adult skin.

This review discusses the potential mechanisms and evidence supporting low-level laser therapy for stimulating hair growth in men and women, while noting its safety and effectiveness but needing further study on specific parameters.

This study demonstrated that cultured human dermal papilla cells can induce full hair follicle formation when combined with neonatal foreskin keratinocytes in a grafted dermal-epidermal construct on mice.

This study developed a 3D engineered hair follicle model that mimics the native hair bulb and may aid in drug screening for hair growth therapies.

This article reviews methods to enhance epithelial–mesenchymal interactions for hair follicle bioengineering but does not present new experimental results; it emphasizes optimizing combinations for successful regeneration.

This study found that ectodermal precursor cells derived from human induced pluripotent stem cells may enhance hair follicle morphogenesis through improved epithelial-mesenchymal interactions when cocultured with dermal cells.

This review discusses recent advances in hair follicle biology, regeneration, and tissue engineering, highlighting emerging therapeutic opportunities, and reports no new experimental results.

This article reviews recent advancements in understanding and treating androgenetic alopecia, focusing on new genetic insights, stem cell roles, and diagnostic tools, without reporting new clinical results.

This study reports the successful generation of inducible pluripotent stem cells from mesenchymal stem cells derived from human hair follicles, marking a novel method of reprogramming these cells.

This study found that both human and rat dermal papilla spheroids can induce hair follicle neogenesis, but larger spheroids increase inductivity without significantly affecting hair fiber diameter.

This review discusses the molecular mechanisms involved in hair follicle development and regeneration, highlighting findings from mouse genetic studies, and reports no new experimental results.

This study demonstrates the potential of using bioengineered follicles from adult tissue-derived stem cells for fully functional hair regeneration, illustrating possible applications in organ replacement therapy.

This study found that dermal papilla cells from human hair follicles can be reprogrammed into induced pluripotent stem cells, but their efficiency is similar to that of fibroblasts, unlike in mice.

This study found that cultured human dermal papilla cells formed into three-dimensional spheres have an increased ability to induce hair follicles from mouse epidermal cells compared to two-dimensional cultures.

This study suggests that human and mouse hair follicle stem cells may support nerve repair and provide a practical source of stem cells for neurological therapies.

This study achieved a first by successfully forming large quantities of dermal papilla spheroidal microtissues, which retained their hair induction potential, using a micropatterned culture system.

This review discusses the role of dermal cells in hair follicle regeneration and morphogenesis and highlights their potential therapeutic implications, but it reports no new empirical findings.

This study developed a method for expanding human dermal papilla cells in vitro while maintaining their ability to induce hair growth, advancing the potential for follicular cell implantation as a treatment for hair loss.

In this study, fibronectin coating on a low-adhesive substratum increased cell aggregation, growth, and motility, enhancing the formation of hair follicle dermal papilla spheroids.

In this study, human hair follicle pluripotent stem cells transplanted into severed mouse sciatic nerves differentiated into Schwann cells and supported nerve regeneration, offering a promising alternative to embryonic or iPS cells for regenerative medicine.

This study presents a novel in vitro assay using human folliculoid microspheres to research hair growth, which may facilitate preclinical testing of hair growth-modulatory agents.

Lgr5 is a marker for active, long-lasting stem cells in mouse hair follicles.

This review discusses the various treatment options for male and female pattern hair loss and provides no new clinical results; the authors outline the most effective strategies based on existing evidence.

In this study, murine follicular cell aggregates developed into hair-like structures in culture, which upon implantation into mice skin matured into complete hair follicles, suggesting potential for treating hair loss.

This study found that poly(ethylene-co-vinyl alcohol) membranes support the self-assembly of dermal papilla cells into compact spheroidal microtissues capable of inducing new hair follicles, suggesting potential for large-scale production for hair follicle regeneration.

The study found that bioengineered hair follicles work when using cells from the same species but have issues when combining human and mouse cells.

In this study, co-grafting human keratinocytes with murine dermal papilla-enriched cells produced hair follicle-like structures, but without regular hair formation, suggesting anomalous folliculogenesis.

This review summarizes recent advances in understanding the molecular mechanisms of hair follicle formation and discusses potential future clinical applications for treating hair loss and skin tumors, but it reports no new clinical results.