Nanomaterials in hair care and treatment

Advancements in silk fibroin and silk sericin-based biomaterial applications for cancer therapy and wound dressing formulation: A comprehensive review

Silks are a class of proteins generated naturally by different arthropods, including silkworms, spiders, scorpions, mites, wasps, and bees. This review discusses the silk fibroin and silk sericin fabricated by Bombyx mori silkworm as versatile fibers. This silk fiber is predominantly composed of hydrophobic silk fibroin and hydrophilic silk sericin. Fibroin is defined as a structural protein that bestows silk with strength, while sericin is characterized as a gum-like protein, tying the two fibrous proteins together and endowing silk proteins with elasticity. Due to their versatile structures, biocompatibility, and biodegradability, they could be tailored into intricate structures to warrant particular demands. The intrinsic functional groups of both proteins enable their functionalization and cross-linking with various biomaterials to endow the matrix with favorable antioxidant and antibacterial properties. Depending on the target applications, they can be integrated with other materials to formulate nanofibrous, hydrogels, films, and micro-nanoparticles. Given the outstanding biological and controllable physicochemical features of fibroin and sericin, they could be exploited in pharmaceutical applications involving tissue engineering, wound repair, drug delivery, and cancer therapy. This review comprehensively discusses the advancements in the implementation of different formulations of silk fibroin and sericin in wound healing and drug delivery systems, particularly for cancer treatment.

Cellulose nanocrystal-stabilized Pickering emulsion gels as vehicles for follicular delivery of minoxidil

Minoxidil (MXD) is the only topical over-the-counter medicine approved by the United States Food and Drug Administration for the treatment of androgenetic alopecia. For the purpose of targeting the delivery of MXD to dermal papilla in the hair follicle, MXD Pickering emulsion gels were fabricated based on the designability of deep eutectic solvent (DES) and the versatility of cellulose nanocrystal (CNC) and sodium carboxymethyl cellulose (CMC-Na). Structural studies and theoretical calculations results suggest that CNC can stabilize the interface between the MXD-DES and water, leading to the formation of Pickering emulsions. The rheological properties and stabilities of MXD Pickering emulsions were enhanced through gelation using CMC-Na, which highlights the good compatibility and effectiveness of natural polysaccharides in emulsion gels. Due to the particle size of emulsion droplets (679 nm) and the rheological properties of emulsion gel, the fabricated MXD formulations show in vivo hair regrowth promotion and hair follicle targeting capabilities. Interestingly, the MXD Pickering emulsion-based formulations exert therapeutic effects by upregulating the expression of hair growth factors. The proposed nanodrug strategy based on supramolecular strategies of CNC and CMC-Na provides an interesting avenue for androgenetic alopecia treatment.

Delivery Strategies of siRNA Therapeutics for Hair Loss Therapy

Therapeutic needs for hair loss are intended to find small interfering ribonucleic acid (siRNA) therapeutics for breakthrough. Since naked siRNA is restricted to meet a druggable target in clinic,, delivery systems are indispensable to overcome intrinsic and pathophysiological barriers, enhancing targetability and persistency to ensure safety, efficacy, and effectiveness. Diverse carriers repurposed from small molecules to siRNA can be systematically or locally employed in hair loss therapy, followed by the adoption of new compositions associated with structural and environmental modification. The siRNA delivery systems have been extensively studied via conjugation or nanoparticle formulation to improve their fate in vitro and in vivo. In this review, we introduce clinically tunable siRNA delivery systems for hair loss based on design principles, after analyzing clinical trials in hair loss and currently approved siRNA therapeutics. We further discuss a strategic research framework for optimized siRNA delivery in hair loss from the scientific perspective of clinical translation.

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.

Traditional Scraping (Gua Sha) Combined with Copper-Curcumin Nanoparticle Oleogel for Accurate and Multi-Effective Therapy of Androgenic Alopecia

Androgenetic alopecia (AGA) is a prevalent systemic disease caused by diverse factors, for which effective treatments are currently limited. Herein, the oleogel (OG) containing copper-curcumin (CuR) nanoparticles is developed, designated as CuRG, which is also combined with traditional naturopathic scraping (Gua Sha, SCR) as a multifunctional therapy for AGA. With the assistance of lipophilic OG and SCR, CuR can efficaciously penetrate the epidermal and dermal regions where most hair follicles (HFs) reside, thereby releasing curcumin (CR) and copper ions (Cu2+) subcutaneously to facilitate hair regeneration. Concomitantly, the mechanical stimulation induced by SCR promotes the formation of new blood vessels, which is conducive to reshaping the microenvironment of HFs. This study validates that the combination of CuRG and SCR is capable of systematically interfering with different pathological processes, ranging from improvement of perifollicular microenvironment (oxidative stress and insufficient vascularization), regulation of inflammatory responses to degradation of androgen receptor, thus potentiating hair growth. Compared with minoxidil, a widely used clinical drug for AGA therapy, the designed synergistic system displays augmented hair regeneration in the AGA mouse model.

Nanocosmeceuticals: Trends and Recent Advancements in Self Care

The term cosmetics refers to any substances or products intended for external application on the skin with the aim of protection and better appearance of the skin surface. The skin delivery system promotes the controlled and targeted delivery of active ingredients. The development of this system has been driven by challenges encountered with conventional cosmeceuticals, including low skin retention of active components, limited percutaneous penetration, poor water dispersion of insoluble active ingredients, and instability of effective components. The aim is to create cosmeceuticals that can effectively overcome these issues. This review focuses on various nanocarriers used in cosmeceuticals currently and their applications in skin care, hair care, oral care, and more. The importance of nanotechnology in the sphere of research and development is growing. It provides solutions to various problems faced by conventional technologies, methods, and product formulations thus taking hold of the cosmetic industry as well. Nowadays, consumers are investing in cosmetics only for better appearance thus problems like wrinkles, ageing, hair loss, and dandruff requires to be answered proficiently. Nanocarriers not only enhance the efficacy of cosmeceutical products, providing better and longer-lasting effects, but they also contribute to the improved aesthetic appearance of the products. This dual benefit not only enhances the final quality and efficacy of the product but also increases consumer satisfaction. Additionally, nanocarriers offer protection against UV rays, further adding to the overall benefits of the cosmeceutical product. Figure 1 represents various advantages of nanocarriers used in cosmeceuticals. Nanotechnology is also gaining importance due to their high penetration of actives in the deeper layers of skin. It can be said that nanotechnology is taking over all the drawbacks of the traditional products. Thus, nanocarriers discussed in this review are used in nanotechnology to deliver the active ingredient of the cosmeceutical product to the desired site.

Thermodynamically stable ionic liquid microemulsions pioneer pathways for topical delivery and peptide application

Copper peptides (GHK-Cu) are a powerful hair growth promoter with minimal side effects when compared with minoxidil and finasteride; however, challenges in delivering GHK-Cu topically limits their non-invasive applications. Using theoretical calculations and pseudo-ternary phase diagrams, we designed and constructed a thermodynamically stable ionic liquid (IL)-based microemulsion (IL-M), which integrates the high drug solubility of ILs and high skin permeability of microemulsions, thus improving the local delivery of copper peptides by approximately three-fold while retaining their biological function. Experiments in mice validated the effectiveness of our proposed IL-M system. Furthermore, the exact effects of the IL-M system on the expression of growth factors, such as vascular endothelial growth factor, were revealed, and it was found that microemulsion increased the activation of the Wnt/β-catenin signaling pathway, which includes factors involved in hair growth regulation. Overall, the safe and non-invasive IL microemulsion system developed in this study has great potential for the clinical treatment of hair loss.

Nanotechnology-based techniques for hair follicle regeneration

The hair follicle (HF) is a multicellular complex structure of the skin that contains a reservoir of multipotent stem cells. Traditional hair repair methods such as drug therapies, hair transplantation, and stem cell therapy have limitations. Advances in nanotechnology offer new approaches for HF regeneration, including controlled drug release and HF-specific targeting. Until recently, embryogenesis was thought to be the only mechanism for forming hair follicles. However, in recent years, the phenomenon of wound-induced hair neogenesis (WIHN) or de novo HF regeneration has gained attention as it can occur under certain conditions in wound beds. This review covers HF-specific targeting strategies, with particular emphasis on currently used nanotechnology-based strategies for both hair loss-related diseases and HF regeneration. HF regeneration is discussed in several modalities: modulation of the hair cycle, stimulation of progenitor cells and signaling pathways, tissue engineering, WIHN, and gene therapy. The HF has been identified as an ideal target for nanotechnology-based strategies for hair regeneration. However, some regulatory challenges may delay the development of HF regeneration nanotechnology based-strategies, which will be lastly discussed.

Bioinspired peptides designed for hair perming and dyeing with potential for repair

Cosmetics for perming hair are commonly used but have negative impacts on hair fibers. Repairing damaged hair with conditioners, hair oil, and hair masks can provide relief but cannot prevent injuries. Recent research has shown that proteins and amino acids can remodel hair's disulfide bonds. However, the permeation ability of proteins is limited, and amino acids may disrupt the secondary structure of hair keratins. Our study demonstrates that peptides can be safely, efficiently, and promisingly used for hair perming. A bioinspired peptide, PepACS (PepA-PepC-SPB), was designed through bioinformatics. It can interact with keratin's sulfhydryl group in situ to remodel disulfide bonds without affecting hair fiber's tensile properties. The potential of PepACS to repair cuticle injuries is also observed through scanning electron microscope visualization. Besides, linking PepACS with mCherry enables hair dyeing. This research suggests that biomaterials can be applied in the hair care industry. STATEMENT OF SIGNIFICANCE: Chemical perming products can have negative impacts on people's health and hair fibers, making it essential to explore alternative methods. Peptides treatment is a promising option, but synthesizing sulfur-rich short peptides for hair perming has not been demonstrated before. In this paper, we utilized bioinformatics to design bio-inspired peptides that can interact with hair keratins and form curled shapes. Our study demonstrates that bioinformatics tools can be utilized to design bioinspired peptides with unique functions. Sulfur-rich short peptides can be heterologously expressed with fusion strategies, and PepACS can securely bind hair fibers through disulfide bonds. Importantly, perming hair with 0.01% PepACS maintains the mechanical properties of hair, and dyeing hair with the fusion protein PepACS_mCh can be facilitated by ethanol. These findings suggest that the strategy of perming and dyeing hair through peptides is non-injurious, and the peptides used for repairing hair damage show tremendous potential.

Collagen Hydrolysate from the Scales of Mozambique Tilapia (Oreochromis mossambicus) Improve Hair and Skin Health by Alleviating Oxidative Stress and Inflammation and Promoting Hair Growth and Extracellular Matrix Factors

Fish-derived collagen hydrolysate (CH) has shown promise in improving hair and skin health. Therefore, this study sought to comprehensively assess the effects of CH extracted from Mozambique tilapia (Oreochromis mossambicus) scales on hair and skin using in vitro and in vivo models. Human dermal papilla cells (hDPCs) were used for antioxidant and gene expression analyses, while C57BL/6 mice were orally administered CH for six weeks to assess hair growth patterns. The mice were divided into four groups: negative control (NC; distilled water), positive control (PC; 1 mg/kg finasteride), CH500 (500 mg/kg BW CH), and CH1000 (1000 mg/kg BW CH). CH mitigated catalase activity reduction in hDPCs, increased IGF-1 and VEGF levels, and decreased TGF-β1, TNF-α, and IL-1β expression. In vivo, CH treatment improved hair growth index, length, diameter, weight, and density. Scanning electron microscopy revealed reduced hair damage. Moreover, CH up-regulated IGF-1, VEGF, Elastin, and HAS2 mRNA expression while down-regulating TNF-α and IL-1β. CH enhanced hair shine, growth, and skin health while alleviating inflammation. These findings demonstrate the potential of CH in alleviating oxidative stress, promoting hair growth, and enhancing skin health, both in vitro and in vivo. Fish-derived CH offers a cost-effective and bioavailable option for improving hair and skin health.

Genetics of hair graying with age

Hair graying is an early and obvious phenotypic and physiological trait with age in humans. Several recent advances in molecular biology and genetics have increased our understanding of the mechanisms of hair graying, which elucidate genes related to the synthesis, transport, and distribution of melanin in hair follicles, as well as genes regulating these processes above. Therefore, we review these advances and examine the trends in the genetic aspects of hair graying from enrichment theory, Genome-Wide association studies, whole exome sequencing, gene expression studies, and animal models for hair graying with age, aiming to overview the changes in hair graying at the genetic level and establish the foundation for future research. Meanwhile, by summarizing the genetics, it's of great value to explore the possible mechanism, treatment, or even prevention of hair graying with age.

An overview on the antibacterial properties of juglone, naphthazarin, plumbagin and lawsone derivatives and their metal complexes

Bacterial resistance development represents a serious threat to human health across the globe and has become a very serious clinical problem for many classes of antibiotics. Hence, there is a constant and urgent need for the discovery and development of new effective antibacterial agents to stem the emergence of resistant bacteria. 1,4-naphthoquinones are an important class of natural products and have been known for decades as a privileged scaffold in medicinal chemistry regarding their many biological properties. The significant biological properties of specific 1,4-naphthoquinones hydroxyderivatives have drawn the attention of researchers in order to find new derivatives with an optimized activity, mainly as antibacterial agents. Based on juglone, naphthazarin, plumbagin and lawsone moieties, structural optimization was realized with the purpose of improving the antibacterial activity. Thereupon, relevant antibacterial activities have been observed on different panels of bacterial strains including resistant ones. In this review, we highlight the interest of developing new 1,4-naphthoquinones hydroxyderivatives and some metal complexes as promising antibacterial agents alternatives. Here, we thoroughly report for the first time both the antibacterial activity and the chemical synthesis of four different 1,4-naphthoquinones (juglone, naphthazarin, plumbagin and lawsone) from 2002 to 2022 with an emphasis on the structure-activity relationship, when applicable.

Recent Advancements in Natural Plant Colorants Used for Hair Dye Applications: A Review

There is an on-going demand in recent years for safer and "greener" hair coloring agents with the global consumer awareness of the adverse effects of synthetic hair dyes. The belief in sustainability and health benefits has focused the attention of the scientific community towards natural colorants that serve to replace their synthetic toxic counterparts. This review article encompasses the historical applications of a vast array of natural plant hair dyes and summarizes the possible coloration mechanisms (direct dyeing and mordant dyeing). Current information on phytochemicals (quinones, tannins, flavonoids, indigo, curcuminoids and carotenoids) used for hair dyeing are summarized, including their botanical sources, color chemistry and biological/toxicological activities. A particular focus is given on research into new natural hair dye sources along with eco-friendly, robust and cost-effective technologies for their processing and applications, such as the synthetic biology approach for colorant production, encapsulation techniques for stabilization and the development of inorganic nanocarriers. In addition, innovative in vitro approaches for the toxicological assessments of natural hair dye cosmetics are highlighted.