Squarticles as a lipid nanocarrier for delivering diphencyprone and minoxidil to hair follicles and human dermal papilla cells

Recent Trends in Macromolecule-Based Approaches for Hair Loss Treatment

Macromolecules are large, complex molecules composed of smaller subunits known as monomers. The four primary categories of macromolecules found in living organisms are carbohydrates, lipids, proteins, and nucleic acids; they also encompass a broad range of natural and synthetic polymers. Recent studies have shown that biologically active macromolecules can help regenerate hair, providing a potential solution for current hair regeneration therapies. This review examines the latest developments in the use of macromolecules for the treatment of hair loss. The fundamental principles of hair follicle (HF) morphogenesis, hair shaft (HS) development, hair cycle regulation, and alopecia have been introduced. Microneedle (MN) and nanoparticle (NP) delivery systems are innovative treatments for hair loss. Additionally, the application of macromolecule-based tissue-engineered scaffolds for the in vitro and in vivo neogenesis of HFs is discussed. Furthermore, a new research direction is explored wherein artificial skin platforms are adopted as a promising screening method for hair loss treatment drugs. Through these multifaceted approaches, promising aspects of macromolecules for future hair loss treatments are identified.

Utilization of response surface design for development and optimization of rosuvastatin calcium-loaded nano-squarticles for hair growth stimulating VEGF and IGF production: in-vitro and in-vivo evaluation

INTRODUCTION

Countless individuals experience negative emotions as hair loss pattern affects their self-esteem and well-being. Rosuvastatin calcium (Ca-RUV) was reported to stimulate the growth of the hair in the applied area, hence, it was selected as a potential hair loss treatment drug.

SIGNIFICANCE

This study aims to develop and optimize (Ca-RUV) loaded squarticles (SQRs) and assess their ability to deliver and release Ca-RUV in the hair follicle for the promotion of hair growth.

METHODS

A response surface design was utilized to study the effect of varying Pluronic® F68 (PF68) and the percentage of liquid lipids within the core of the SQRs and the effects of particle size, entrapment efficiency, and drug released percentage after 24 h (%Q24) were assessed. The optimized formula was subjected to DSC, XRD, and in-vivo evaluation in rats.

RESULTS

SQRs stabilized by 0.8% PF68 and contained 37.5% liquid lipids showed an acceptable particle size (250 nm), drug entrapment efficiency (75%), and %Q24 (100%). The in-vivo studies illustrated the ability of the formula to regrow hair in animals after 10 days due to the elevation of the vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF-1) to their normal values and by 9% and 54%, respectively, relative to standard therapy minoxidil (5%).

CONCLUSION

Thus, it can be concluded that the optimized formula of Ca-RUV loaded SQRs showed superior in-vivo results in the promotion of hair growth in a shorter period relative to the marketed product. Therefore, the formula can offer a viable option for the treatment of hair loss.

Advances and Prospects for Hydrogel-Forming Microneedles in Transdermal Drug Delivery

Transdermal drug delivery (TDD) is one of the key approaches for treating diseases, avoiding first-pass effects, reducing systemic adverse drug reactions and improving patient compliance. Microneedling, iontophoresis, electroporation, laser ablation and ultrasound facilitation are often used to improve the efficiency of TDD. Among them, microneedling is a relatively simple and efficient means of drug delivery. Microneedles usually consist of micron-sized needles (50-900 μm in length) in arrays that can successfully penetrate the stratum corneum and deliver drugs in a minimally invasive manner below the stratum corneum without touching the blood vessels and nerves in the dermis, improving patient compliance. Hydrogel-forming microneedles (HFMs) are safe and non-toxic, with no residual matrix material, high drug loading capacity, and controlled drug release, and they are suitable for long-term, multiple drug delivery. This work reviewed the characteristics of the skin structure and TDD, introduced TDD strategies based on HFMs, and summarized the characteristics of HFM TDD systems and the evaluation methods of HFMs as well as the application of HFM drug delivery systems in disease treatment. The HFM drug delivery system has a wide scope for development, but the translation to clinical application still has more challenges.

Selective Delivery of Tofacitinib Citrate to Hair Follicles Using Lipid-Coated Calcium Carbonate Nanocarrier Controls Chemotherapy-Induced Alopecia Areata

Chemotherapy-induced alopecia (CIA) is one of the common side effects in cancer treatment. The psychological distress caused by hair loss may cause patients to discontinue chemotherapy, affecting the efficacy of the treatment. The JAK inhibitor, Tofacitinib citrate (TFC), showed huge potential in therapeutic applications for treating baldness, but the systemic adverse effects of oral administration and low absorption rate at the target site limited its widespread application in alopecia. To overcome these problems, we designed phospholipid-calcium carbonate hybrid nanoparticles (PL/ACC NPs) for a topical application to target deliver TFC. The results proved that PL/ACC-TFC NPs showed excellent pH sensitivity and transdermal penetration in vitro. PL/ACC NPs offered an efficient follicular targeting approach to deliver TFC in a Cyclophosphamide (CYP)-induced alopecia areata mouse model. Compared to the topical application of TFC solution, PL/ACC-TFC NPs significantly inhibited apoptosis of mouse hair follicles and accelerated hair growth. These findings support that PL/ACC-TFC NPs has the potential for topical application in preventing and mitigating CYP-induced Alopecia areata.

An overview of topical lipid-based and polymer-based nanocarriers for treatment of psoriasis

Psoriasis is a consistently recurring, inflammatory skin disease, affecting about 2 - 5 % of the world population. Different types of psoriasis can be observed such as guttate psoriasis, pustular psoriasis, psoriatic arthritis, scalp psoriasis, flexural psoriasis etc. Several therapeutic approaches are available for the treatment of psoriasis. However, none of them are entirely safe and effective to treat the disease without compromising patient compliance. The traditional treatment plan is associated with harmful side effects such asimmune system suppression and damage of essential organs at high doses, which poses a challenge to treat psoriasis. Novel drug delivery systems are being developed to replace traditional therapy in order to address these shortcomings. Currently, nanoformulations have gained widespread application for treatment of psoriasis. Researchers have developed different types of lipid-based nanoparticles like liposomes, niosomes, ethosomes, transethosomes, nanostructured lipid carriers and solid lipid nanoparticles. These innovative formulations provide advantages in terms of reduction in dose, dosing frequency, dose-dependency with enhanced efficacy, improved encapsulation efficiency, controlled release, increased surface area, high bioavailability and greater stratum corneum permeability. This review highlights detailed and comparative discussion of lipid-based and polymer-based nanoparticles for psoriasis along with the pathophysiology and other treatments of psoriasis.

Effects of Natural Polyphenols on Skin and Hair Health: A Review

The skin is the largest organ of the body and plays multiple essential roles, ranging from regulating temperature, preventing infections, to ultimately affecting human health. A hair follicle is a complex cutaneous appendage. Skin diseases and hair loss have a significant effect on the quality of life and psychosocial adjustment of individuals. However, the available traditional drugs for treating skin and hair diseases may have some insufficiencies; therefore, a growing number of researchers are interested in natural materials that could achieve satisfactory results and minimize adverse effects. Natural polyphenols, named for the multiple phenolic hydroxyl groups in their structures, are promising candidates and continue to be of scientific interest due to their multifunctional biological properties and safety. Polyphenols have a wide range of pharmacological effects. In addition to the most common effect, antioxidation, polyphenols have anti-inflammatory, bacteriostatic, antitumor, and other biological effects associated with reduced risk of a number of chronic diseases. Various polyphenols have also shown efficacy against different types of skin and hair diseases, both in vitro and in vivo, via different mechanisms. Thus, this paper reviews the research progress in natural polyphenols for the protection of skin and hair health, especially focusing on their potential therapeutic mechanisms against skin and hair disorders. A deep understanding of natural polyphenols provides a new perspective for the safe treatment of skin diseases and hair loss.

Advances in nanotechnology-based hair care products applied to hair shaft and hair scalp disorders

OBJECTIVE

Nanotechnology has been intensively applied to the development of novel cosmetic products for hair and scalp care during the last decades. Such a trend is corroborated by the fact that about 19% of the total nanocosmetics registered in the StatNano database are intended for hair and scalp care. Nanotechnology-enabled formulations based on nanoparticles, cyclodextrins, liposomes and nanoemulsions have emerged as novel approaches due to chemical stability and their controlled release. Regarding hair care formulations, nanocarriers can target the hair shaft, hair follicle and scalp. Therefore, they have been used to treat several hair disorders, including dandruff and other hair-damaging conditions.

METHODS

This review addressed the most important nanocarriers applied to hair-related disorders improvement. Furthermore, the application for hair photoprotection and improvement of hair colour duration by nanotechnological formulations is also approached. Besides, we provided an overview of the current scenario of available nano-based commercial hair products and novel patented inventions.

RESULTS

From the patent search, the Patent Cooperation Treaty was pointed as the most important depositing agency while the United States of America has been the most depositing country. On the contrary, according to the StatNano database, Brazil stands out in the hair care worldwide market, and it is also the main producer of hair cosmetics based on nanotechnology.

CONCLUSION

As nano-based products offer several advantages over conventional cosmetics, it is expected that in future, there will be more research on nanocarriers applied to hair disorders, as well as commercial products and patent applications.

Nanomaterials in hair care and treatment

Hair care and treatment has evolved significantly through the years as new formulations are continuously being explored in an attempt to meet the demand in cosmetic and medicinal fields. While standard hair care procedures include hair washing, aimed at hair cleansing and maintenance, as well as hair dyeing and bleaching formulations for hair embellishment, modern hair treatments are mainly focused on circumventing hair loss conditions, strengthening hair follicle properties and treat hair infestations. In this regard, active compounds (ACs) included in hair cosmetic formulations include a vast array of hair cleansing and hair dye molecules, and typical hair treatments include anti-hair loss ACs (e.g. minoxidil and finasteride) and anti-lice ACs (e.g. permethrin). However, several challenges still persist, as conventional AC formulations exhibit sub-optimal performance and some may present toxicity issues, calling for an improved design of formulations regarding both efficacy and safety. More recently, nano-based strategies encompassing nanomaterials have emerged as promising tailored approaches to improve the performance of ACs incorporated into hair cosmetics and treatment formulations. The interest in using these nanomaterials is based on account of their ability to: (1) increase stability, safety and biocompatibility of ACs; (2) maximize hair affinity, contact and retention, acting as versatile biointerfaces; (3) enable the controlled release of ACs in both hair and scalp, serving as prolonged AC reservoirs; besides offering (4) hair follicle targeting features attending to the possibility of surface tunability. This review covers the breakthrough of nanomaterials for hair cosmetics and hair treatment, focusing on organic nanomaterials (polymer-based and lipid-based nanoparticles) and inorganic nanomaterials (nanosheets, nanotubes and inorganic nanoparticles), as well as their applications, highlighting their potential as innovative multifunctional nanomaterials towards maximized hair care and treatment. STATEMENT OF SIGNIFICANCE: This manuscript is focused on reviewing the nanotechnological strategies investigated for hair care and treatment so far. While conventional formulations exhibit sub-optimal performance and some may present toxicity issues, the selection of improved and suitable nanodelivery systems is of utmost relevance to ensure a proper active ingredient release in both hair and scalp, maximize hair affinity, contact and retention, and provide hair follicle targeting features, warranting stability, efficacy and safety. This innovative manuscript highlights the advantages of nanotechnology-based approaches, particularly as tunable and versatile biointerfaces, and their applications as innovative multifunctional nanomaterials towards maximized hair care and treatment.

Nanostructured Drug Delivery Systems for Targeting 5-α-Reductase Inhibitors to the Hair Follicle

Androgenetic alopecia is a multifactorial condition characterized by noticeable hair loss, affecting both men and women and representing a debilitating and chronic disorder that considerably affects the quality of life. Available topical treatments based on minoxidil or finasteride require repeated applications and are associated with a certain number of adverse effects. The challenges associated with current treatments pave the way for the research of new therapeutic strategies, more precise and selective, and capable of providing long-term results. In this context, the present review examines the new proposed formulation strategies to deliver 5-α-reductase inhibitors in order to obtain a targeted drug delivery, for improving drug retention at the site of action in the hair follicle, contemporaneously reducing drug systemic absorption, which is the cause of important adverse effects. In particular, the research will be focused on the several aspects that influence the performance of nanostructured drug delivery systems in creating a depot in the hair follicles, such as particle size, surface charge, excipients, and combined application with external stimuli (infrared radiation, mechanical massage, ultrasounds application).

The Antibiofilm Nanosystems for Improved Infection Inhibition of Microbes in Skin

Biofilm formation is an important virulence factor for the opportunistic microorganisms that elicit skin infections. The recalcitrant feature of biofilms and their antibiotic tolerance impose a great challenge on the use of conventional therapies. Most antibacterial agents have difficulty penetrating the matrix produced by a biofilm. One novel approach to address these concerns is to prevent or inhibit the formation of biofilms using nanoparticles. The advantages of using nanosystems for antibiofilm applications include high drug loading efficiency, sustained or prolonged drug release, increased drug stability, improved bioavailability, close contact with bacteria, and enhanced accumulation or targeting to biomasses. Topically applied nanoparticles can act as a strategy for enhancing antibiotic delivery into the skin. Various types of nanoparticles, including metal oxide nanoparticles, polymeric nanoparticles, liposomes, and lipid-based nanoparticles, have been employed for topical delivery to treat biofilm infections on the skin. Moreover, nanoparticles can be designed to combine with external stimuli to produce magnetic, photothermal, or photodynamic effects to ablate the biofilm matrix. This study focuses on advanced antibiofilm approaches based on nanomedicine for treating skin infections. We provide in-depth descriptions on how the nanoparticles could effectively eliminate biofilms and any pathogens inside them. We then describe cases of using nanoparticles for antibiofilm treatment of the skin. Most of the studies included in this review were supported by in vivo animal infection models. This article offers an overview of the benefits of nanosystems for treating biofilms grown on the skin.

Potential of nanoparticulate based delivery systems for effective management of alopecia

In recent times, more than 50 % of the global population is facing hair-related issues (alopecia) which is seen mostly amongst the people in the age group of 30-40 years. The conventional topical dosage forms available in the market falls short in effectively managing alopecia. Despite various advancements in topical dosage forms, it is still disposed to limited clinical application and provides poor penetration of drug molecules into the skin. The exact etiology of alopecia is still unknown and various researchers link lifestyle, hereditary, and auto immune-based events with its existence. Nanoparticulate-based delivery are hence brought in use to enhance the permeability properties of the drug. In comparison to conventional methods nanotechnology-based drug delivery system tames drug molecules to a specific site with much better efficacy. This review is engrossed in the journey and role of nano technological-based drug delivery in the management of alopecia and its clinical application.

Transdermal Delivery of Macromolecules Using Nano Lipid Carriers

Skin being the largest external organ, offers an appealing procedure for transdermal drug delivery, so the drug needs to reach above the outermost layer of the skin, i.e., stratum corneum. Small molecular drug entities obeying the Lipinski rule, i.e., drugs having a molecular weight less than 500 Da, high lipophilicity, and optimum polarity, are favored enough to be used on the skin as therapeutics. Skin's barrier properties prevent the transport of macromolecules at pre-determined therapeutic rates. Notable advancements in macromolecules' transdermal delivery have occurred in recent years. Scientists have opted for liposomes, the use of electroporation, low-frequency ultrasound techniques, etc. Some of these have shown better delivery of macromolecules at clinically beneficial rates. These physical technologies involve complex mechanisms, which may irreversibly incur skin damage. Majorly, two types of lipid-based formulations, including Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), are widely investigated as transdermal delivery systems. In this review, the concepts, mechanisms, and applications of nanostructured lipid carriers used to transport macromolecules via transdermal routes are thoroughly reviewed and presented along with their clinical perspective.

Topical Treatment for Scarring and Non-Scarring Alopecia: An Overview of the Current Evidence

Alopecia is a clinical condition related to hair loss that can significantly affect both male and female adults' quality of life. Despite the high market demand, only few drugs are currently approved for alopecia treatment. Topical formulations still bring drawbacks, such as scalp irritation with frequent use, and low drug absorption to the site of action, which limits the efficacy. The most recent research points out that different formulation technology could circumvent the aforementioned flaws. Such technology includes incorporation of drugs in rigid or deformable nanoparticles, strategies involving physical, energetical and mechanical techniques, such as iontophoresis, sonophoresis, microneedling, and the use of solid effervescent granules to be hydrated at the moment of application in the scalp. In this paper, the progress of current research on topical formulations dedicated to the treatment of alopecia is reviewed and discussed.

Skin penetration/permeation success determinants of nanocarriers: Pursuit of a perfect formulation

The advent of nanocarriers in the field of pharmaceutical drug delivery, while exhibiting considerable advantages, has created challenges for researchers. Among the applications of nanocarriers, drug delivery to the skin has attracted increasing attention in recent decades due to its advantages over oral and parenteral administration. Accordingly, this work attempts to discuss the major obstacles surrounding topically applied formulations and different nanocarriers' potential to overcome these barriers to investigate whether their passive penetration through the skin is likely. Therefore, skin anatomical views and transcutaneous pathways are briefly reviewed. Factors commonly thought to influence skin penetration are discussed from the perspective of particularly penetrating nanocarriers. The formulation of these nanocarriers is outlined, and promising constituents are highlighted to help investigators optimize nanocarrier formulations.

Nanoemulsions containing plant oils: How do they influence hair treatment?

OBJECTIVE

Cosmetic and dermatological products, mainly the hair treatments, are projected to have remarkable growing in coming years. Nanotechnology, specifically nanoemulsions, has potential to be used in several hair products, owing to their beneficial properties. Concurrently, plant-derived cosmetics have become more popular over the years to consumers who prefer a safer, natural and sustainable approach. There is a lack of studies combining plant oils and nanotechnology for haircare formulations. In this work, different plant oil-loaded nanoemulsions were prepared to investigate the influence of their particle size, zeta potential and composition on hair treatment efficacy.

METHODS

Coconut, olive and Abyssinian oils, alone or in combination, were loaded into nanoemulsions by high-pressure homogenization method (HPH). The mean particle size, polydispersity index and zeta potential were measured by the dynamic light scattering (DLS) method, and a stability test was performed for five months. A sensorial screening evaluation performed by the analyst and the combing test using Dia-Stron^® instrumentation were applied on hair tresses treated by these nanoemulsions.

RESULTS

The use of different plant oils for nanoemulsion resulted in distinct final particle sizes and zeta potential. However, results suggested no significant difference between them in hair tresses combing efficacy compared by Dia-Stron^® instrument testing. Moreover, the plant-loaded nanoemulsions with increased concentration of cationic surfactant indicated a 50% reduction in combing force using this device when compared to control, in addition to better sensory results by screening test compared to other nanoemulsions and control.

CONCLUSION

The composition of plant oils, particle size or zeta potential of the prepared nanoemulsions does not seem to significantly influence hair performance. Thus, we suggest that finding the right balance between cationic surfactant and plant oils may be the most appropriate path to develop effective nanoemulsions in hair treatment.

Latanoprost Loaded in Polymeric Nanocapsules for Effective Topical Treatment of Alopecia

Latanoprost has recently been used to treat alopecia as it causes an increase in the capillary density of patients. This work presents for the first time the development of polymeric nanocapsules containing latanoprost for the topical treatment of alopecia. Poly-ε-caprolactone nanocapsules loading latanoprost were developed by nanoprecipitation of the polymer on the surface of drug oily nanodroplets. The method encapsulated 93.9 ± 0.4% of the drug into nanocapsules of 197.8 (± 1.2) nm (PdI = 0.15 ± 0.01). The nanosystem presented a zeta potential equal to - 30.1 ± 1.8 mV and was stable for at least 90 days when stored at 6°C. The colloidal aqueous dispersion was non-irritating, according to the in vitro HET-CAM test. The nanocapsules improved latanoprost accumulation into the hair follicles when topically applied on porcine skin, delivering 30% more drug to these skin structures relative to the control solution (P < 0.05). Also, with a simple manual massage, latanoprost accumulation was increased by twofold (P < 0.05). In conclusion, in addition to being a stable and safe formulation, nanocapsules enhanced latanoprost accumulation into the hair follicles, being a nanosystem with high potential for use as a topical formulation for the treatment of androgenic alopecia.

Development and Characterization of a Clobetasol Propionate Nanostructured Lipid Carrier-Based Gel for the Treatment of Plaque Psoriasis

BACKGROUND

Psoriasis is an autoimmune disease of the skin with lapsing episodes of hyperkeratosis, irritation, and inflammation. Numerous traditional and novel drug delivery systems have been used for better penetration through psoriatic barrier cells and also for retention in the skin. As there is no effective remedy for better penetration, and retention is there because of the absence of an ideal carrier for effective and safe delivery of antipsoriatic drugs.

OBJECTIVES

The main objective of this project is to develop a Squalene integrated NLC based carbopol 940 gel to create a local drug depot in the skin for improved efficacy against psoriasis.

METHODS

Homogenization method is used for the formulation of Nanostructured Lipid Carrier, which was characterized on the basis of size, entrapment efficiency, polydispersity index (PDI), viscosity, spreadability, DSC, zeta potential, % in vitro release, in vitro skin permeation and retention studies, physical storage stability studies. In vivo studies can use other alternative models for induction of psoriasis by severe redness, swelling macroscopically, and microvascular dilation edema lasting for 10 days. Furthermore, histopathology study was done to asses changes in the skin.

CONCLUSION

The optimized formulation of nanostructured lipid carrier-based gel has shown significant and sustained release of clobetasol propionate. Furthermore, this formulation has also shown retention in skin because of squalene as it is a sebum derived lipid, which shows an affinity towards the sebaceous gland.

Development and characterisation of clobetasol propionate loaded Squarticles as a lipid nanocarrier for treatment of plaque psoriasis

Aim: The aim of this project is to improve the therapeutic effectiveness, permeation and retention of clobetasol propionate in sebaceous glands by reporting the use of Squarticles as lipidic nanosystem.Methods: Homogenisation method is used for the formulation of Squarticles (nanoemulgel) which was characterised on the basis of size, polydispersity index (PDI), viscosity, spreadability, DSC, % in vitro release, in vitro skin permeation deposition studies, and in vivo studies, scanning electron microscopic (SEM) and physical storage stability studies were done at different temperature conditions, i.e. 4 ± 2 °C, 25 ± 2 °C and 45 ± 2 °C for a period of 6 months for drug and formulation.Result: The morphological characterisation of prepared nanoemulsion shows small spherical shape and uniform size distribution as observed in the Scanning electron microscopic (SEM), having mean size (240.5 ± 9.2) and mean size distribution (0.282 ± 0.03) and zeta potential (-51.21). The drug release from optimised nanoemulsion (F2) in PBS (pH 5.5) was approximately 84.24 ± 1.35%, nanoemulgel formulations showed the release of 66.83 ± 2.05% while marketed gel showed the release of 57.67 ± 1.63% after 24 h. The cumulative percentage retention of clobetasol propionate loaded nanoemulgel was 63 ± 1.28% which was more than the marketed formulation (23.12% ±0.54). Physical stability studies show that formulation is more stable in cold condition. Further, the stability of active ingredient in gel formulation was determined using HPLC which shows around 15 ± 0.84% of loss in its activity.Conclusion: The present work has demonstrated the use of Squarticles as a novel carrier for treatment of plaque psoriasis by enhancing the better permeation, increasing skin retention, and enhances the effect of drug. The study also shows that the formulation is more stable in cold condition.

Topical Minoxidil-Loaded Nanotechnology Strategies for Alopecia

Androgenetic alopecia (AGA) is a multifactorial and age-related condition characterized by substantial hair loss affecting both men and women. Conventional treatments include the use of topical minoxidil (MNX) formulations to stimulate hair growth and restore hair condition. However, those treatments are associated with limited performance and a lack of tolerability and compliance due to the emergence of adverse effects. Considering that the development of nanotechnology-based formulations as hair loss therapeutic strategies has been clearly growing, topical MNX delivery by means of these innovative formulations is known to enhance MNX skin permeation and depot formation into hair follicles, allowing for MNX-controlled release, increased MNX skin bioavailability and enhanced therapeutic efficacy with minimal adverse effects. This review highlights the potential of nanotechnology-based MNX delivery formulations for improved hair loss therapeutics, including a thorough assessment of their in vitro and in vivo performances, as well as regulatory and nanosafety considerations.

SLN and NLC for topical, dermal, and transdermal drug delivery

Introduction: From a biopharmaceutical standpoint, the skin is recognized as an interesting route for drug delivery. In general, small molecules are able to penetrate the stratum corneum, the outermost layer of the skin. In contrast, the delivery of larger molecules, such as peptides and proteins, remains a challenge. Nanoparticles have been exploited not only to enhance skin penetration of drugs but also to expand the range of molecules to be clinically used.Areas covered: This review focus on Solid lipid nanoparticles (SLN) and Nanostructured lipid carriers (NLC) for skin administration. We discuss the selection criteria for lipids, surfactants, and surface modifiers commonly in use in SLN/NLC, their production techniques, and the range of drugs loaded in these lipid nanoparticles for the treatment of skin disorders.Expert opinion: Depending on the lipid and surfactant composition, different nanoparticle morphologies can be generated. Both SLN and NLC are composed of lipids that resemble those of the skin and sebum, which contribute to their enhanced biocompatibility, with limited toxicological risk. SLN and NLC can be loaded with very chemically different drugs, may provide a tunable release profile, can be produced in a sterilized environment, and be scaled-up without the need for organic solvents.

Nanotechnology advances for hair loss

Alopecia is the partial or total reduction of hair in a specific area of the skin that affects millions of men and women worldwide. Most common approved treatments present inconvenient therapeutic regimes and serious adverse effects. In this scenario, nanoencapsulation has emerged as a relatively simple technology for improving the therapeutic outcome of this pathology, promoting a targeted drug delivery with enhanced local bioavailability, which could reduce the adverse effects. Herein, we present some recent studies involving the nanosystems developed for the pharmacological treatment of alopecia, highlighting how each system represents an improvement in relation to conventional drug products and the future perspectives of these new technologies in reaching the market.

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.

Oleic Acid Nanovesicles of Minoxidil for Enhanced Follicular Delivery

Current topical minoxidil (MXD) formulations involve an unpleasant organic solvent which causes patient incompliance in addition to side effects in some cases. Therefore, the objective of this work was to develop an MXD formulation providing enhanced follicular delivery and reduced side effects. Oleic acid, being a safer material, was utilized to prepare the nanovesicles, which were characterized for size, entrapment efficiency, polydispersity index (PDI), zeta potential, and morphology. The nanovesicles were incorporated into the emugel Sepineo^® P 600 (2% w/v) to provide better longer contact time with the scalp and improve physical stability. The formulation was evaluated for in vitro drug release, ex vivo drug permeation, and drug deposition studies. Follicular deposition of the vesicles was also evaluated using a differential tape stripping technique and elucidated using confocal microscopy. The optimum oleic acid vesicles measured particle size was 317 ± 4 nm, with high entrapment efficiency (69.08 ± 3.07%), narrow PDI (0.203 ± 0.01), and a negative zeta potential of −13.97 ± 0.451. The in vitro drug release showed the sustained release of MXD from vesicular gel. The skin permeation and deposition studies revealed superiority of the prepared MXD vesicular gel (0.2%) in terms of MXD deposition in the stratum corneum (SC) and remaining skin over MXD lotion (2%), with enhancement ratios of 3.0 and 4.0, respectively. The follicular deposition of MXD was 10-fold higher for vesicular gel than the control. Confocal microscopy also confirmed the higher absorption of rhodamine via vesicular gel into hair follicles as compared to the control. Overall, the current findings demonstrate the potential of oleic acid vesicles for effective targeted skin and follicular delivery of MXD.

Engineering the niche for hair regeneration - A critical review

Recent progress in hair follicle regeneration and alopecia treatment necessitates revisiting the concepts and approaches. In this sense, there is a need for shedding light on the clinical and surgical therapies benefitting from nanobiomedicine. From this perspective, this review attempts to recognize requirements upon which new hair therapies are grounded; to underline shortcomings and opportunities associated with recent advanced strategies for hair regeneration; and most critically to look over hair regeneration from nanomaterials and pluripotent stem cell standpoint. It is noteworthy that nanotechnology is able to illuminate a novel path for reprogramming cells and controlled differentiation to achieve the desired performance. Undoubtedly, this strategy needs further advancement and a lot of critical questions have yet to be answered. Herein, we introduce the salient features, the hurdles that must be overcome, the hopes, and practical constraints to engineer stem cell niches for hair follicle regeneration.

Is the Fractional Laser Still Effective in Assisting Cutaneous Macromolecule Delivery in Barrier-Deficient Skin? Psoriasis and Atopic Dermatitis as the Disease Models

PURPOSE

Most of the investigations into laser-assisted skin permeation have used the intact skin as the permeation barrier. Whether the laser is effective in improving cutaneous delivery via barrier-defective skin is still unclear.

METHODS

In this study, ablative (Er:YAG) and non-ablative (Er:glass) lasers were examined for the penetration of peptide and siRNA upon topical application on in vitro skin with a healthy or disrupted barrier.

RESULTS

An enhanced peptide flux (6.9 fold) was detected after tape stripping of the pig stratum corneum (SC). A further increase of flux to 11.7 fold was obtained after Er:YAG laser irradiation of the SC-stripped skin. However, the application of Er:glass modality did not further raise the flux via the SC-stripped skin. A similar trend was observed in the case of psoriasiform skin. Conversely, the flux was enhanced 3.7 and 2.6 fold after treatment with the Er:YAG and the Er:glass laser on the atopic dermatitis (AD)-like skin. The 3-D skin structure captured by confocal microscopy proved the distribution of peptide and siRNA through the microchannels and into the surrounding tissue.

CONCLUSIONS

The fractional laser was valid for ameliorating macromolecule permeation into barrier-disrupted skin although the enhancement level was lower than that of normal skin.

Potential enhancement and targeting strategies of polymeric and lipid-based nanocarriers in dermal drug delivery

Nanocarriers used for alternative drug-delivery strategies have gained interest due to improved penetration and delivery of drugs into specific regions of the skin in recent years. Dermal drug delivery via polymeric-based nanocarriers (polymeric nanoparticles, micelles, dendrimers) and lipid-based nanocarriers (solid–lipid nanoparticles and nanostructured lipid carriers, vesicular nanocarriers including liposomes, niosomes, transfersomes and ethosomes) has been widely investigated. Although penetration of nanocarriers through the intact skin could be restricted, these carriers are particularly considered as feasible for the treatment of dermatological diseases in which the skin barrier is disrupted and also for follicular delivery of drugs for management of skin disorders such as acne. This review mainly highlights the recent approaches on potential penetration enhancement and targeting mechanisms of these nanocarriers.

Squarticles as the nanoantidotes to sequester the overdosed antidepressant for detoxification

The increasing death rate caused by drug overdose points to an urgent demand for the development of novel detoxification therapy. In an attempt to detoxify tricyclic antidepressant overdose, we prepared a lipid nanoemulsion, called squarticles, as the nanoantidote. Squalene was the major lipid matrix of the squarticles. Here, we present the animal study to investigate both the pharmacokinetic and pharmacodynamic effects of squarticles on amitriptyline intoxication. The anionic and cationic squarticles had average diameters of 97 and 122 nm, respectively. Through the entrapment study, squarticles could intercept 40%–50% of the amitriptyline during 2 h with low leakage after loading into the nanoparticles. The results of isothermal titration calorimetry demonstrated greater interaction of amitriptyline with the surface of anionic squarticles (K_a =28,700) than with cationic ones (K_a =5,010). Real-time imaging showed that intravenous administration of anionic squarticles resulted in a prolonged retention in the circulation. In a rat model of amitriptyline poisoning, anionic squarticles increased the plasma drug concentration by 2.5-fold. The drug uptake in the highly perfused organs was diminished after squarticle infusion, indicating the lipid sink effect of bringing the entrapped overdosed drug in the tissues back into circulation. In addition, the anionic nanosystems restored the mean arterial pressure to near normal after amitriptyline injection. The survival rate of overdosed amitriptyline increased from 25% to 75% by treatment with squarticles. Our results show that the adverse effects of amitriptyline intoxication could be mitigated by administering anionic squarticles. This lipid nanoemulsion is a potent antidote to extract amitriptyline and eliminate it.

Isolation and structural identification of a novel minoxidil analogue in an illegal dietary supplement: triaminodil

A new minoxidil analogue was detected in an illegal dietary supplement advertised as a hair-growth treatment. The analogue was identified using ultra-performance liquid chromatography (UPLC), high-resolution mass spectrometry (LC-HR-MS) and nuclear magnetic resonance (NMR) spectroscopy. The compound was structurally elucidated as a minoxidil analogue in which the piperidinyl group of minoxidil was replaced with a pyrrolidinyl group corresponding to a molecular formula of C₈H₁₃N₅O. The new analogue has been named triaminodil. As this is the first report of the compound, there are no chemical, toxicology or pharmacological data available.

Vesicles: Potential nano carriers for the delivery of skin cosmetics

In the present scenario, consumers are searching for personal care products that supply multiple benefits with minimal efforts. The outcome has been the introduction of nanotechnology-based cosmetic products that are safe to use and results driven. Some topical cosmetics can act efficaciously when they reach their target sites present in the deeper layers of the skin. The main problem with delivering active ingredients across the skin is the barrier function of the skin. Therefore, to get the maximum benefit from cosmetic products and to overcome the problems associated with their skin penetration, scientists are investigating various strategies to overcome these barrier properties. Vesicular carriers have been claimed to improve the topical delivery of active ingredients. This review offers a brief overview of current approaches in the research and development of vesicular carriers to improve the delivery and performance of active ingredients present in the cosmetics.

New Horizons in the Development of Novel Needle-Free Immunization Strategies to Increase Vaccination Efficacy

The young twenty-first century has already brought several medical advances, such as a functional artificial human liver created from stem cells, improved antiviral (e.g., against HIV) and cancer (e.g., against breast cancer) therapies, interventions controlling cardiovascular diseases, and development of new and optimized vaccines (e.g., HPV vaccine). However, despite this substantial progress and the achievements of the last century, humans still suffer considerably from diseases, especially from infectious diseases. Thus, almost one-fourth of all deaths worldwide are caused directly or indirectly by infectious agents. Although vaccination has led to the control of many diseases, including smallpox, diphtheria, and tetanus, emerging diseases are still not completely contained. Furthermore, pathogens such as Bordetella pertussis undergo alterations making adaptation of the respective vaccine necessary. Moreover, insufficient implementation of vaccination campaigns leads to re-emergence of diseases which were believed to be already under control (e.g., poliomyelitis). Therefore, novel vaccination strategies need to be developed in order to meet the current challenges including lack of compliance, safety issues, and logistic constraints. In this context, mucosal and transdermal approaches constitute promising noninvasive vaccination strategies able to match these demands.

Detection of vasodilator drugs through microwave spectroscopy of Au NP colorimetric probes using a microwave metallic photonic crystal-inspired resonant probe

A low-cost, time-effective and easy-to-use novel analytical technique incorporating microwave spectroscopy of unmodified gold nanoparticles for the detection of selected vasodilator drugs.

Topical and cutaneous delivery using nanosystems

The goal of topical and cutaneous delivery is to deliver therapeutic and other substances to a desired target site in the skin at appropriate doses to achieve a safe and efficacious outcome. Normally, however, when the stratum corneum is intact and the skin barrier is uncompromised, this is limited to molecules that are relatively lipophilic, small and uncharged, thereby excluding many potentially useful therapeutic peptides, proteins, vaccines, gene fragments or drug-carrying particles. In this review we will describe how nanosystems are being increasingly exploited for topical and cutaneous delivery, particularly for these previously difficult substances. This is also being driven by the development of novel technologies, which include minimally invasive delivery systems and more precise fabrication techniques. While there is a vast array of nanosystems under development and many undergoing advanced clinical trials, relatively few have achieved full translation to clinical practice. This slow uptake may be due, in part, to the need for a rigorous demonstration of safety in these new nanotechnologies. Some of the safety aspects associated with nanosystems will be considered in this review.

Preclinical safety of solid lipid nanoparticles and nanostructured lipid carriers: Current evidence from in vitro and in vivo evaluation

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were designed as exceptionally safe colloidal carriers for the delivery of poorly soluble drugs. SLN/NLC have the particularity of being composed of excipientsalready approved for use in medicines for human use, which offers a great advantage over any other nanoparticulate system developed from novel materials. Despite this fact, any use of excipients in new route of administration or in new dosage form requires evidence of safety. After 25 years of research on SLN and NLC, enough evidence on their preclinical safety has been published. In the present work, published data on in vitro and in vivo compatibility of SLN/NLC have been surveyed, in order to provide evidence of high biocompatibility distinguished by intended administration route. We also identified critical factors and possible weak points in SLN/NLC formulations, such as the effect of surfactants on the cell viability in vitro, which should be considered for further development.

Site-Directed Conjugation of Antibodies to Apoferritin Nanocarrier for Targeted Drug Delivery to Prostate Cancer Cells

Herein, we describe a novel approach for targeting of ubiquitous protein apoferritin (APO)-encapsulating doxorubicin (DOX) to prostate cancer using antibodies against prostate-specific membrane antigen (PSMA). The conjugation of anti-PSMA antibodies and APO was carried out using HWRGWVC heptapeptide, providing their site-directed orientation. The prostate-cancer-targeted and nontargeted nanocarriers were tested using LNCaP and HUVEC cell lines. A total of 90% of LNCaP cells died after treatment with DOX (0.25 μM) or DOX in nontargeted and prostate-cancer-targeted APO, proving that the encapsulated DOX toxicity for LNCaP cells remained the same. Free DOX showed higher toxicity for nonmalignant cells, whereas the toxicity was lower after treatment with the same dosage of APO-encapsulated DOX (APODOX) and even more in prostate-cancer-targeted APODOX. Hemolytic assay revealed exceptional hemocompatibility of the entire nanocarrier. The APO encapsulation mechanism ensures applicability using a wide variety of chemotherapeutic drugs, and the presented surface modification enables targeting to various tumors.

Applications and limitations of lipid nanoparticles in dermal and transdermal drug delivery via the follicular route

Lipid nanoparticles (LN) such as solid lipid nanoparticles (SLN) and nanolipid carriers (NLC) feature several claimed benefits for topical drug therapy including biocompatible ingredients, drug release modification, adhesion to the skin, and film formation with subsequent hydration of the superficial skin layers. However, penetration and permeation into and across deeper skin layers are restricted due to the barrier function of the stratum corneum (SC). As different kinds of nanoparticles provide the potential for penetration into hair follicles (HF) LN are applicable drug delivery systems (DDS) for this route in order to enhance the dermal and transdermal bioavailability of active pharmaceutical ingredients (API). Therefore, this review addresses the HF as application site, published formulations of LN which showed follicular penetration (FP), and characterization methods in order to identify and quantify the accumulation of API delivered by the LN in the HF. Since LN are based on lipids that appear in human sebum which is the predominant medium in HF an increased localization of the colloidal carriers as well as a promoted drug release may be assumed. Therefore, sebum-like lipid material and a size of less or equal 640 nm are appropriate specifications for FP of particulate formulations.