Topical liposome targeting of dyes, melanins, genes, and proteins selectively to hair follicles

Unlocking the Medicinal Potential of Plant-Derived Extracellular Vesicles: current Progress and Future Perspectives

Botanical preparations for herbal medicine have received more and more attention from drug researchers, and the extraction of active ingredients and their successful clinical application have become an important direction of drug research in major pharmaceutical companies, but the complexity of extracts, multiple side effects, and significant individual differences have brought many difficulties to the clinical application of herbal preparations. It is noteworthy that extracellular vesicles as active biomolecules extracted from medicinal plants are believed to be useful for the treatment of a variety of diseases, including cancer, inflammation, regenerative-restorative and degenerative diseases, which may provide a new direction for the clinical utilization of herbal preparations. In this review, we sort out recent advances in medicinal plant extracellular vesicles and discuss their potential as disease therapeutics. Finally, future challenges and research directions for the clinical translation of medicinal plant extracellular vesicles are also discussed, and we expect that continued development based on medicinal plant extracellular vesicles will facilitate the clinical application of herbal preparations.

Plant Exosome-like Nanoparticles as Biological Shuttles for Transdermal Drug Delivery

Exosomes act as emerging transdermal drug delivery vehicles with high deformability and excellent permeability, which can be used to deliver various small-molecule drugs and macromolecular drugs and increase the transdermal and dermal retention of drugs, improving the local efficacy and drug delivery compliance. At present, there are many studies on the use of plant exosome-like nanoparticles (PELNVs) as drug carriers. In this review, the source, extraction, isolation, and chemical composition of plant exosomes are reviewed, and the research progress on PELNVs as drug delivery systems in transdermal drug delivery systems in recent years has elucidated the broad application prospect of PELNVs.

Review on Plants with Traditional Uses and Bio-Activity Against Hair Graying

Abstract:

Hair graying occurs worldwide, and it has a high impact on the self-esteem of an individual. Hair graying is a melanogenesis disorder that can be attributed to many factors, including age, oxidative stress, psychological stress, and malnutrition. Though there are effective p-phenylenediamine based hair dyes, they often cause allergy and systematic toxicity. Plants are popular a traditional remedy for the management of hair disorders. Due to their high chemical diversity, phytoproducts offer great promises to develop an effective and safe product to manage hair graying and melanogenesis disorders. The aim of the present article is to review plants with traditional uses and bio-activity against hair graying. An extensive literature search was conducted on PubMed, Science Direct, and Google Scholar databases using many combinations of the following keywords: plants used to treat gray hair, natural products, hair graying, melanogenesis, pigmentation, and tyrosinase activity. This review documented about sixty-one plants, including a summary of 47 plants frequently used in traditional medicine, and a brief review of fourteen plants showing promising activity against hair graying. The active constituents and the mechanisms by which active constituents exert anti-hair graying effects were also reviewed.

Plant Exosome-like Nanovesicles: Emerging Therapeutics and Drug Delivery Nanoplatforms

Plant exosome-like nanovesicles, being innately replete with bioactive lipids, proteins, RNA, and other pharmacologically active molecules, offer unique morphological and compositional characteristics as natural nanocarriers. Furthermore, their compelling physicochemical traits underpin their modulative role in physiological processes, all of which have fostered the concept that these nanovesicles may be highly proficient in the development of next-generation biotherapeutic and drug delivery nanoplatforms to meet the ever-stringent demands of current clinical challenges. This review systemically deals with various facets of plant exosome-like nanovesicles ranging from their origin and isolation to identification of morphological composition, biological functions, and cargo-loading mechanisms. Efforts are made to encompass their biotherapeutic roles by elucidating their immunological modulating, anti-tumor, regenerative, and anti-inflammatory roles. We also shed light on re-engineering these nanovesicles into robust, innocuous, and non-immunogenic nanovectors for drug delivery through multiple stringent biological hindrances to various targeted organs such as intestine and brain. Finally, recent advances centered around plant exosome-like nanovesicles along with new insights into transdermal, transmembrane and targeting mechanisms of these vesicles are also elucidated. We expect that the continuing development of plant exosome-like nanovesicle-based therapeutic and delivery nanoplatforms will promote their clinical applications.

The impact of skin massage frequency on the intrafollicular transport of silica nanoparticles: Validation of the ratchet effect on an ex vivo porcine skin model

The human hair follicle (HF) represents a promising drug delivery target as an anatomical entity by itself, but also as a gateway enabling dermal or systemic bioavailability of active cosmetic and pharmaceutical ingredients. Due to its morphological characteristics, the HF provides a mechanically driven transport process of nanoparticles (NPs) when external forces are applied. This mechanism was presented as the so-called ratchet effect within the framework of an in silico study published recently. To investigate the influence of massage frequency on the penetration depth of NPs, and, by this, to validate the results obtained in silico, we implemented a corresponding application protocol on an ex vivo porcine skin model. In this connection, we compared three different skin massage frequencies (4.2 Hz, 50 Hz, 100 Hz) for the topical application of cyanine 5-labeled silica NPs (Cy5-SNPs). To elucidate the interplay of frequency and particle size, we furthermore applied Cy5-SNPs of three different diameters (300 nm, 676 nm, 1000 nm). Confocal laser scanning microscopy was utilized to investigate the follicular penetration depth of Cy5-SNPs on cryohistological slices. By this, we could demonstrate that the massage frequency and the follicular penetration depth exhibit an inverse relation pattern. Thus, the highest follicular penetration depth was observed within the 4.2 Hz group, while the lowest follicular penetration depth was found within the 100 Hz group for each Cy5-SNP size category. Additionally, we found that 676 nm Cy5-SNPs penetrated significantly deeper into HFs than 300 nm Cy5-SNPs and 1000 nm Cy5-SNPs, respectively. Summarizing, our results show that a low massage frequency including a dominant radial direction component leads to deeper follicular penetration depths of NPs than automated 3D-oscillation massage at 50 Hz or 100 Hz. Thus, our findings are in line with recent in silico results. Regarding translational purposes, our results are of high interest, since a massage executed at 250BPM (4.2 Hz) is within a realizable range for manual application, e.g. for the implementation into clinical routines or the domestic use of drugs or cosmetics. Furthermore, the application of different massage frequencies offers the opportunity of patho-specific targeting as different anatomical parts of the HF can be reached.

Deformable liposomes as enhancer of caffeine penetration through human skin in a Franz diffusion cell test

OBJECTIVE

The permeation of hydrophilic molecules through the skin is still a challenge due to the barrier posed by stratum corneum, the outermost layer of the skin. Liposomes have frequently been used as carriers for different types of drugs and may also function as permeation enhancers. Propylene glycol has also been used as an edge activator in liposomes to increase the permeation. The aim of this work was to prepare liposomes containing an edge activator and loaded with caffeine to evaluate the potential of caffeine reaching the deeper layers in the skin.

METHODS

The formulations were prepared by a top-down process using high-pressure homogenization at 200 00 psi for 10 min. They were characterized by size, polydispersity index (PI), zeta potential (ZP), pH, caffeine content and encapsulation efficiency (EE%) on preparation (time zero) and after 30 days. Cytotoxicity of blank and loaded liposomes was assessed by MTT proliferation assay with a normal keratinocyte cell line (HaCaT). In vitro permeation tests were performed with human skin in Franz cells over 24 h, and caffeine concentration was determined in the skin surface, stratum corneum, dermo-epidermal fraction and receptor medium by HPLC.

RESULTS

The caffeine liposomes with (DL-Caf) or without propylene glycol (CL-Caf) showed, respectively, mean size 94.5 and 95.4 nm, PI 0.48 and 0.42, ZP + 1.3 and + 18.1 mV and caffeine content of 78.57 and 80.13%. IC₅₀ values of caffeine in DL-Caf (3.59 v/v %) and CL-Caf (3.65 v/v %) were not significantly different from conventional blank liposome (3.27 v/v %). The DL-Caf formulation presented the best capability to enhance the caffeine permeation through the skin, resulting 1.94-folds higher than caffeine solution. Furthermore, the caffeine flux from DL-Caf was 1.56- and 3.05-folds higher than caffeine solution and CL-Caf, respectively. On the other hand, CL-Caf showed the lowest caffeine penetration revealing the importance of edge activator to aid hydrophilic drug penetration to all skin layers.

CONCLUSION

The DL-Caf formulation tested was able to improve the permeation of caffeine through the stratum corneum and dermo-epidermal layers, suggesting that this delivery system may be effective for deep skin delivery of hydrophilic drugs.

Outer membrane vesicles derived from E. coli as novel vehicles for transdermal and tumor targeting delivery

Transdermal drug delivery is favored in clinical therapy because of its ability to overcome the shortcomings of the first pass elimination of the liver caused by traditional oral administration and the irreversibility of the injection. However, skin stratum corneum (SC) forms a big barrier that precludes most of the biomacromolecules. Herein, we propose the engineering of transformed Escherichia coli (E. coli) derived outer membrane vesicles, detoxified by lysozymes (named TEVs) as the carrier for transdermal drug delivery. TEVs were derived from transgenic E. coli and then modified by an integrin alpha(v)beta(3) (αvβ3) targeting peptide and co-loaded with indocyanine green (ICG) (P-TEVs-G). TEVs were shown to have excellence in penetrating through intact SC without any additional enhancement, followed by targeting of melanoma cells. TEVs are promising nanoplatforms for transdermal and tumor targeting drug delivery with high efficacy and biosafety, possessing great potential in the treatment of superficial tumors.

Engineering bacterial outer membrane vesicles as transdermal nanoplatforms for photo-TRAIL-programmed therapy against melanoma

Melanoma is an aggressive cancer with rapid progression, relapse, and metastasis. Systemic therapies for melanoma exhibit limited anticancer potential and high toxicity. Here, we developed the outer membrane vesicles derived from transgenic Escherichia coli, modified with αvβ3 integrin peptide targeting ligand and indocyanine green (named as I-P-OMVs), to induce the transdermal photo-TRAIL-programmed treatment in skin melanoma.-OMVs, which are outer membrane vesicles derived from transgenic Escherichia coli, modified with αvβ3 integrin targeting ligand and indocyanine green (named as I-P-OMVs), to induce the transdermal photo-TRAIL-programmed treatment in skin melanoma. I-P-OMVs exhibited excellent stratum corneum penetration and specificity to melanoma. Upon near-infrared irritation, I-P-OMVs not only induced photothermal-photodynamic responses against primary melanoma spheroids but also activated TRAIL-induced apoptosis in disseminated tumor cells, resulting in a complete eradication of melanoma. I-P-OMVs are the first nanoplatforms to induce transdermal photo-TRAIL-programmed therapy in melanoma with enhanced antitumor performance and high safety, having great potential in cancer therapy.

A Simple Non-Invasive Approach toward Efficient Transdermal Drug Delivery Based on Biodegradable Particulate System

Transdermal administration via skin appendages enables both localized and systemic drug delivery, as well as minimizes incidental toxicity. However, the design of an appropriate effective method for clinical use remains challenging. Here, we introduce calcium carbonate-based carriers for the transdermal transportation of bioactive substances. The proposed system presents easily manufacturable biodegradable particles with a large surface area enabling a high payload ability. Topical application of submicron porous CaCO₃ particles in rats followed by the therapeutic ultrasound treatment results in their deep penetration through the skin along with plentiful filling of the hair follicles. Exploiting the loading capacity of the porous particles, we demonstrate efficient transportation of a fluorescent marker along the entire depth of the hair follicle down the bulb region. In vivo monitoring of the carrier degradation reveals the active dissolution/recrystallization of CaCO₃ particles, resulting in their total resorption within 12 days. The proposed particulate system serves as an intrafollicular depot for drug storage and prolonged in situ release over this period. The urinary excretion profile proves the systemic absorption of the fluorescent marker. Hence, the elaborated transdermal delivery system looks promising for medical applications. The drug delivery to different target regions of the hair follicle may contribute to regenerative medicine, immunomodulation, and treatment of various skin disorders. In the meantime, the systemic uptake of the transported drug opens an avenue for prospective delivery routes beyond the scope of dermatology.

Premature Graying of Hair: Review with Updates

Premature graying of hair (PGH) is defined as graying of hair before the age of 20 years in Caucasians and before 30 years in African American population. It can severely affect the self-esteem of an individual. The exact etiopathogenesis remains unknown, although it has been associated with premature aging disorders, atopy, and autoimmune diseases. Patients, who present with PGH, should be assessed for syndromes and metabolism diseases. Hair dyes remain the main modality of the treatment for cosmetic concerns after nutritional supplementation.

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.

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.

Water-soluble dopamine-based polymers for photoacoustic imaging

Here we present a facile synthetic method yielding a linear form of polydopamine via Kumada-coupling, which can be converted into water-soluble melanin, generating high contrast in photoacoustic imaging.

Nucleic acid delivery into skin for the treatment of skin disease: Proofs-of-concept, potential impact, and remaining challenges

Nucleic acids (NAs) hold significant potential for the treatment of several diseases. Topical delivery of NAs for the treatment of skin diseases is especially advantageous since it bypasses the challenges associated with systemic administration which suffers from enzymatic degradation, systemic toxicity and lack of targeting to skin. However, the skin's protective barrier function limits the delivery of NAs into skin after topical application. Here, we highlight strategies for enhancing delivery of NAs into skin, and provide evidence that translation of topical NA therapies could have a transformative impact on the treatment of skin diseases.

Microneedling dilates the follicular infundibulum and increases transfollicular absorption of liposomal sepia melanin

Encapsulation of chemicals in liposomes and microneedling are currently used techniques to enhance the penetration of several substances through skin and hair. In this study, we apply a liposomal melanin–fluorescein compound to an ex vivo model of human skin, using a new electrical microneedling device (Nanopore turbo roller). The product was applied by hand massage (A) or with the assistance of the electrical roller for 2 minutes (B). An additional test was performed free of product and with only the E-roller (C). Histological changes and product absorption were evaluated by optical and fluorescent microscopy 60 and 90 minutes after the treatment. Site B showed larger deposits of melanin–fluorescein at superficial and deep levels of hair structures in comparison to site A. Light, epidermal deposits of the melanin–fluorescein complex were also observed. Sites B and C showed a significant widening (47%) of the follicular infundibulum which could explain the increased penetration of the formulation. Microneedling also removed the scales and sebum residues in the neighborhood of the infundibulum. Targeting hair follicles with melanin may be useful to dye poorly pigmented hairs, improving laser hair removal. The procedure accelerates the delivery of melanin into hair structures allowing an even absorption, larger pigment deposits, and deeper penetration of the formulation into the hair.

Treatment of vitiligo with khellin liposomes, ultraviolet light and blister roof transplantation

BACKGROUND

Various surgical and non-surgical methods are available to treat vitiligo. Surgical techniques such as epidermal blister graft transplantation may be effective for the re-pigmentation of stable, but refractory vitiligo areas. Khellin has phototherapeutic properties that are similar to those of the psoralens, but with substantially lower phototoxic effects and DNA mutation effects. Its penetration into the hair follicles is enhanced by encapsulating it into liposomes. Subsequent activation of the khellin with UV light stimulates the melanocytes in the hair follicles.

OBJECTIVE

The first objective was to evaluate the additional value of combining blister roof transplantation (BRT) with khellin in liposomes and ultraviolet light (KLUV) in the treatment of recalcitrant vitiligo patches. The second objective was to assess patients' satisfaction.

MATERIALS AND METHODS

Nineteen patients with vitiligo lesions which did not respond to KLUV treatment for at least a year were treated with BRT followed by KLUV. The transplantation was performed by creating blisters with a suction device, preparing the target site with Erbium laser ablation and the actual transplantation. Locations where randomly assigned. A blinded observer established the results.

RESULTS

Seventy-five percent of the patients were satisfied with the cosmetic result. All of the patients would recommend the treatment to other vitiligo patients. More than 75% re-pigmentation of the vitiligo areas was noted in 47% of the patients according to the blinded evaluation of photographs taken before and after the treatment.

Development and characterization of minoxidil-loaded liposomal system for delivery to pilosebaceous units

PRIMARY OBJECTIVE

To examine the generator of frontal somatosensory evoked potentials by studying patients with traumatic brain injury in the chronic phase.

RESEARCH DESIGN

A prospective, non-comparative case series.

METHODS AND PROCEDURES

Median nerve somatosensory evoked potentials were performed in 26 survivors of severe traumatic brain injury, which had taken place at a mean of 7 months before. Potentials of short latency somatosensory evoked potentials were recorded simultaneously over the frontal and parietal scalp.

MAIN OUTCOMES AND RESULTS

Frontally recorded latencies N18, P20 and N13 recorded from C2 correlated highly significantly with the duration of coma (p<0.01), a history of raised intracranial pressure (p<0.05) and with each other (p<0.01) in traumatic brain injury patients.

CONCLUSIONS

These findings indicate that frontally recorded N18, P20 and N13 recorded from C2 are generated in part in the brainstem, which becomes damaged by increased intracranial pressure due to secondary injury in severe traumatic brain injury.

Carriers in the topical treatment of skin disease

Topical drug application is less prone to severe systemic side-effects than systemic application. Starting with the liposomes, various types of nanosized and microsized drug carriers have been developed to increase the notoriously low penetration of active agents into the skin, which limits not only the topical therapy of skin disease but also transdermal therapy. Today, liposome- and microsponge-based preparations are approved for dermatomycosis, acne and actinic keratosis. Under investigation are drug carriers such as lipid nanoparticles, polymeric particles, dendrimers, and dendritic-core multi-shell nanotransporters. According to the rapidly increasing research in this field, both in academia and industry, a breakthrough appears likely, once stability problems (nanoparticles) and safety concerns (dendrimers) are overcome. Technical approaches and results of in vitro, ex vivo and in vivo testing are described, taking into account pharmacokinetic, efficacy and safety aspects.

Aging of hair

The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life expectation, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and also more capable to deliver active products that are directed toward meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft and aging of the hair follicle. The latter manifests as decrease of melanocyte function or graying, and decrease in hair production in androgenetic and senescent alopecia. The scalp is also subject to intrinsic or physiologic aging and extrinsic aging caused by external factors. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation. Prototypes are familial premature graying and androgenetic alopecia. Extrinsic factors include ultraviolet radiation and smoking. Experimental evidence supports the hypothesis that oxidative stress plays a role in skin and hair aging. Topical anti-aging compounds for hair include humefactants, hair conditioners, photoprotectors, and antioxidants. Current available treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil, oral finasteride, and autologous hair transplantation. In the absence of another way to reverse hair graying, hair colorants are the mainstays of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are under current investigation.

Strategy of topical vaccination with nanoparticles

Liposomes in the nanosize range have been recognized as a versatile drug delivery system of both hydrophilic and lipophilic molecules. In order to develop a liposome-based topical vaccination strategy, five different types of liposomes were tested as a putative vaccine delivery system on pig ear skin. The investigated liposomes mainly varied in size, lipid composition, and surface charge. Using hydrophilic and hydrophobic fluorescent dyes as model drugs, penetration behavior was studied by means of confocal laser scanning microscopy of intact skin and histological sections, respectively. Follicular penetration of the liposomes was measured in comparison to a standard, nonliposomal formulation at different time points. Dependent on time but independent of their different characters, the liposomes showed a significantly higher penetration depth into the hair follicles compared to the standard formulation. The standard formulation reached a relative penetration depth of 30% of the full hair follicle length after seven days, whereas amphoteric and cationic liposomes had reached approximately 70%. Penetration depth of negatively charged liposomes did not exceed 50% of the total follicle length. The fluorescence dyes were mainly detected in the hair follicle; only a small amount of dye was found in the upper parts of the epidermis.

Dissecting the impact of chemotherapy on the human hair follicle: a pragmatic in vitro assay for studying the pathogenesis and potential management of hair follicle dystrophy

Chemotherapy-induced alopecia represents one of the major unresolved problems of clinical oncology. The underlying molecular pathogenesis in humans is virtually unknown because of the lack of adequate research models. Therefore, we have explored whether microdissected, organ-cultured, human scalp hair follicles (HFs) in anagen VI can be exploited for dissecting and manipulating the impact of chemotherapy on human HFs. Here, we show that these organ-cultured HFs respond to a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC), in a manner that resembles chemotherapy-induced HF dystrophy as it occurs in vivo: namely, 4-HC induced melanin clumping and melanin incontinence, down-regulated keratinocyte proliferation, massively up-regulated apoptosis of hair matrix keratinocytes, prematurely induced catagen, and up-regulated p53. In addition, 4-HC induced DNA oxidation and the mitochondrial DNA common deletion. The organ culture system facilitated the identification of new molecular targets for chemotherapy-induced HF damage by microarray technology (eg, interleukin-8, fibroblast growth factor-18, and glypican 6). It was also used to explore candidate chemotherapy protectants, for which we used the cytoprotective cytokine keratinocyte growth factor as exemplary pilot agent. Thus, this novel system serves as a powerful yet pragmatic tool for dissecting and manipulating the impact of chemotherapy on the human HF.

Percutaneous Penetration Enhancers: An Overview

Transdermal drug delivery is the controlled release of drugs through the skin to obtain therapeutic levels systematically. Several technological advances have been made in the recent decades to enhance percutaneous drug penetration. This overview focuses on the physical, biochemical, and chemical means of penetration enhancement, as well as the classification and mechanisms of chemical penetration enhancers, their application in transdermal drug delivery, and trends and development in penetration enhancement.

Antisense oligonucleotide targeting fibroblast growth factor receptor (FGFR)-1 stimulates cellular activity of hair follicles in an in vitro organ culture system

BACKGROUND

The hair cycle is regulated by various molecules, among which FGF-5 has been shown to promote the transition from anagen to catagen. The FGFR-1, a trans-membrane receptor of FGF-5 with tyrosine kinase activity, is localized in the follicular papilla of hair follicles.

OBJECTIVES

In order to apply the antisense oligonucleotides targeting FGFR-1 as a treatment for baldness, we examined the effect of the oligonucleotides on hair follicle growth in a serum-free organ culture system.

METHODS

Vibrissal hair follicles from C3H/He mice were cultured in the presence of a reagent at 31 degrees C in 95% O(2)-5% CO(2) for 72 h. A 20-mer antisense nucleotide and its randomly arranged counterpart were prepared by predicting the effective target site of FGFR-1 mRNA. Cellular activity in the hair bulb was estimated by measuring the fluorescence intensity (FI) of the medium after incubation with AlamarBlue dye.

RESULTS

The addition of 30 microM of the phosphorothioate form of antisense oligonucleotide (A1561TS) to the media increased the FI by 30%, whereas the control produced no detectable change. This effect was reproducible dose-dependent with maximal stimulation at 30 microM. Incorporation of the oligonucleotide into the follicular papilla was histologically confirmed by incubation with FITC-labeled phosphorothioate oligonucleotides, and the intact morphological structure of the hair bulb was maintained intact after a 72-h incubation.

CONCLUSIONS

These results suggest the clinical utility of antisense nucleotide targeting FGFR-1 as a treatment for baldness.

A Randomized, Controlled, Double-Blind Study Evaluating Melanin-Encapsulated Liposomes as a Chromophore for Laser Hair Removal of Blond, White, and Gray Hair

INTRODUCTION

Laser hair removal of blond and white hair is a complicated task with often unsatisfactory results as a result of a lack of laser-absorbing chromophore. In the present study, we investigated if repetitive external application of liposomal melanin (Lipoxome; Dalton Medicare B.V., Zevenbergschen Hoek, The Netherlands) enables removal of blond/white and gray hair with a diode laser.

METHODS

Forty-two areas of blond, gray, or white facial and body hair of 16 patients were treated with a liposomal melanin spray (Lipoxome) and 3 cycles of 800 nm diode laser at intervals of 8 weeks (28-40 J/cm). A control group of 16 patients applied physiological saline spray before diode laser treatment. Hair regrowth was measured 8 weeks after each cycle and additionally 6 months after the last treatment by counting the number of terminal hairs compared with baseline pretreatment values. Complications and treatment outcomes were documented.

RESULTS

Mean regrowth in the liposomal melanin group was 83% after 3 treatment cycles. Six months after therapy, average terminal hair count compared with baseline pretreatment showed 14% reduction. Although significant difference was seen compared with the control group showing a 10% reduction of hair growth after 6 months (P < 0.05), the clinical outcome was disappointing.

CONCLUSIONS

Melanin-encapsulated liposomal spray in combination with diode laser treatment showed significant higher efficacy in the treatment of white and blond hair compared with a control group. However, the clinically observed hair reduction was so weak that additional effort as well as higher costs argues against the application of the tested formulation.

Cyproterone Acetate Loading to Lipid Nanoparticles for Topical Acne Treatment: Particle Characterisation and Skin Uptake

PURPOSE

Topical cyproterone acetate (CPA) treatment of skin diseases should reduce side effects currently excluding the use in males and demanding contraceptive measures in females. To improve skin penetration of the poorly absorbed drug, we intended to identify the active moiety and to load it to particulate carrier systems.

MATERIALS AND METHODS

CPA metabolism in human fibroblasts, keratinocytes and a sebocyte cell line as well as androgen receptor affinity of native CPA and the hydrolysis product cyproterone were determined. CPA 0.05% loaded solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), a nanoemulsion and micropheres were characterized for drug-particle interaction and CPA absorption using human skin ex-vivo.

RESULTS

Native CPA proved to be the active agent. Application of CPA attached to SLN increased skin penetration at least four-fold over the uptake from cream and nanoemulsion. Incorporation into the lipid matrix of NLC and microspheres resulted in a 2-3-fold increase in CPA absorption. Drug amounts within the dermis were low with all preparations. No difference was seen in the penetration into intact and stripped skin.

CONCLUSION

With particulate systems topical CPA treatment may be an additional therapeutic option for acne and other diseases of the pilosebaceous unit.

Lipid vesicles for skin delivery of drugs: reviewing three decades of research

Since liposomes were first shown to be of potential value for topical therapy by Mezei and Gulasekharam in 1980, studies continued towards further investigation and development of lipid vesicles as carriers for skin delivery of drugs. Despite this long history of intensive research, lipid vesicles are still considered as a controversial class of dermal and transdermal carriers. Accordingly, this article provides an overview of the development of lipid vesicles for skin delivery of drugs, with special emphasis on recent advances in this field, including the development of deformable liposomes and ethosomes.

Innovative Liposomes as a Transfollicular Drug Delivery System: Penetration into Porcine Hair Follicles

Liposomes had been widely used for drug delivery in the past. In this study, five different liposomes were used as a follicular delivery system in pig ear skin. The liposomes mainly differed in their sphere diameter, lipid composition, and surface charge. A novel class of liposomes being amphoteric in their charge behavior are compared to established anionic and cationic liposomes. Two different fluorescent dyes, hydrophilic carboxyfluoresceine or lipophilic curcumin, were enclosed in the liposomes and used as model drugs. The fluorescent dyes were also applied in a standard formulation for reference. The penetration depth of the dyes was measured by laser scanning microscopy in histological sections. One hour, 3, 5, and 7 days after application, biopsies were taken and the penetration depth into the hair follicle was measured in longitudinal sections. The liposomes showed a higher penetration depth compared to the standard formulation. The relative penetration depth of the dyes, applied in the standard formulation, averaged 30% of the full follicle length during the whole observation period, whereas the liposomal formulations penetrated considerably deeper into the hair follicles. Amphoteric and cationic liposomes reached an average relative penetration depth of approximately 70% of the full hair follicle length.

Pharmacologic interventions in aging hair

The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation.

[Alopecia areata in animal models--new insights into pathogenesis and treatment of a T cell-mediated autoimmune disorder]

Alopecia areata is a common disease, but for ethical reasons it seems difficult to perform large-scale studies to elucidate the pathogenesis and to develop new therapeutic approaches in man. It is therefore helpful to develop appropriate animal models. The Dundee experimental bald rat (DEBR) and the C3H/HeJ mouse are well-established animal models for alopecia areata and can be used for the study of genetic aspects, pathogenesis and therapy of the disease. In C3H/HeJ mice alopecia areata can be experimentally induced by grafting lesional skin from an affected mouse to a histocompatible recipient which offers the possibility to study the influence of various factors on the development of the disease. Studies on the C3H/HeJ mouse and the DEBR have corroborated the concept that alopecia areata is a T-cell mediated autoimmune disease and various steps and aspects of the pathogenesis have been elucidated. Based on this knowledge new therapeutic options may be developed such as inhibition of lymphocyte-homing by an anti-CD44v10 antibody, or inhibition of costimulation by monoclonal antibodies. Therapeutic studies in the C3H/HeJ mouse and the DEBR suggest that alopecia areata can be treated by topical tacrolimus but treatment in humans may only be successful after development of an improved vehicle that facilitates penetration of tacrolimus down to the hair bulb. Current investigations in mice are designed to elucidate the mechanisms how contact sensitizers act in the treatment of alopecia areata, and this will hopefully lead to the development of more specific approaches based on the beneficial effect of contact sensitizers.

Dermocosmetic aspects of hair and scalp

Hair cosmetic agents are preparations intended for placing in contact with the hair and scalp, with the purpose of cleansing, promoting attractiveness, altering appearance, and/or protecting them in order to maintain them in good condition. Current shampoo formulations and styling products are tailored to the variations associated with age, gender, hair quality, hair care habit, and specific problems relating to the superficial condition of the scalp. The great amount of variables to be accounted for, some of them contradictory and hard to bring into accord, makes adequate product formulation a challenge and requires continuous research. Recent hair cosmetic developments include topical hair growth stimulants, photoprotectors, and anti-aging compounds. The advances in molecular technology have opened the avenue to the study of the molecular basis of hair growth and its deviations, as well as of the aging process. The discovery of potential pharmacological targets and the development of selective and effective delivery systems following topical application indicate further strategies for maintenance of healthy hair and scalp in the young and old.

Expression pattern and intensity of protoporphyrin IX induced by liposomal 5-aminolevulinic acid in rat pilosebaceous unit throughout hair cycle

We have developed liposomal formulation of 5-aminolevulinic acid (ALA) to enhance topical delivery and examined ALA-induced protoporpyrin (PpIX) expression in rat pilosebaceous unit throughout hair cycle. Two types of liposomes--glycerol dilaulate (GDL) and phosphatidylcholine (PC)--were formulated and both liposomal ALA increased PpIX expression in rat dorsal skin and pilosebaceous units when compared with free ALA. However, iontophoresis combined with liposomal ALA reduced the expression intensity of PpIX in hair bulbs although it achieved deeper and wider expression of PpIX through transfollicular pathway. After topical application in intact or depilated rat skin, liposomal ALA produced excellent PpIX expression in pilosebaceous units. The expression pattern and intensity of PpIX changed in hair cycle-dependent manner: specific expression only in sebaceous glands was observed at telogen; strong expression in whole pilosebaceous units was shown at anagen with intense expressions in hair bulbs and sebaceous glands; and a pattern similar to anagen but reduced intensity in the hair bulbs was seen at catagen. Throughout hair cycle, the expression pattern and intensity were dramatically changed in hair follicular epithelial cells depending on the cell density and proliferation activity of those cells, whereas those were consistent in sebaceous glands regardless of hair cycle. Little expression was shown in dermis. Photoactivation effect of 20% liposomal ALA-PDT using a red filtered-halogen lamp damaged sebaceous glands, hair follicles and epidermal layers. Formation of a thicker epidermal layer was observed, and hair induction after depilation was inhibited along with damage in sebaceous glands.

On-Line Diffusion Profile of a Lipophilic Model Dye in Different Depths of a Hair Follicle in Human Scalp Skin

In skin and hair research, drug targeting to the hair follicle is of great interest in the treatment of skin diseases. The aim of this study is to visualize on-line the diffusion processes of a model fluorophore into the hair follicle at different depths using fresh human scalp skin and confocal laser scanning microscopy. Up to a depth of 500 microm in the skin, a fast increase of fluorescence is observed in the gap followed by accumulation of the dye in the hair cuticle. Penetration was also observed via the stratum corneum and the epidermis. Little label reached depths greater than 2000 microm. Fat cells accumulated the label fastest, followed by the cuticular area and the outer root sheath of the hair follicle. Sweat glands revealed very low staining, whereas the bulb at a depth of 4000 microm was visualized only by autofluorescence. From this study, we conclude that on-line visualization is a promising technique to access diffusion processes in deep skin layers even on a cellular level. Furthermore, we conclude that the gap and the cuticle play an important role in the initial diffusion period with the label in the cuticle originating from the gap.

Liposomes and niosomes as topical drug delivery systems

The skin acts as a major target as well as a principle barrier for topical/transdermal (TT) drug delivery. The stratum corneum plays a crucial role in barrier function for TT drug delivery. Despite major research and development efforts in TT systems and the advantages of these routes, low stratum corneum permeability limits the usefulness of topical drug delivery. To overcome this, methods have been assessed to increase permeation. One controversial method is the use of vesicular systems, such as liposomes and niosomes, whose effectiveness depends on their physicochemical properties. This review focuses on the effect of liposomes and niosomes on enhancing drug penetration, and defines the effect of composition, size and type of the vesicular system on TT delivery.

Enhanced transfollicular delivery of adriamycin with a liposome and iontophoresis

To find a better way to deliver drugs into hair follicles, we tried two approaches: single topical application using various liposomes; and iontophoresis combined with topical application of ionic liposome. After delivery of adriamycin (ADR) to wax-depilated rat skin, the transport of the drug was examined under fluorescence microscopy. Most liposomal ADR showed more effective transdermal and transfollicular penetration than free ADR. Among tested liposomes, the non-ionic GDL liposome (GDL/CH/POE-10 = glycerol dilaulate/cholesterol/polyoxyethylene-10) was the most selective to hair follicles against skin, while the cationic liposome (GDL/CH/POE-10/DOTAP, dioleoyl trimethylammonium propane) containing monocationic DOTAP was less selective; however, it was better at improving the delivery amount and penetration of ADR into the follicles and skin. The DMPC/DMPG (7/3) formulation of anionic PC liposome (DMPC/DMPG = dimyristoyl-phosphocholine/-phospoglycerol) showed results similar to the cationic liposome. The DMPC/DMPG (3/7) formulation yielded poor results, however, probably because of its increased viscosity and anionic property. Although ADR delivery was enhanced by liposomal formulations, topical applications had some limitations in delivery capacity and speed. To accelerate delivery, iontophoresis was combined with the cationic liposome at positive 0.2-0.4 mA/cm(2) for 20-30 min. The resulting delivery of ADR through follicular routes was excellent. This combination method diffused ADR 3.0-fold more efficiently, rapidly and deeply than single topical application of cationic liposomal ADR. This system also achieved a 3.5-fold higher diffusive follicular delivery than a free ADR/iontophoresis combination. Furthermore, it was demonstrated that the tetracationic lipid DOSPER and hydrophile spermine could serve as a cationic additive instead of the monocationic DOTAP in the liposome. These results suggest that the combinative system of the topically applied cationic liposome followed by iontophoresis has a significant synergistic effect on the transfollicular delivery of ADR.

Site-specific methylene blue delivery to pilosebaceous structures using highly porous nylon microspheres: an experimental evaluation

PURPOSE

This study aimed to evaluate the penetration of methylene blue (MB)-loaded microspheres into pilosebaceous structures of rats.

MATERIALS AND METHODS

MB was incorporated into 5 microm highly porous nylon microspheres. The microspheres were dispersed into fluid silicone. Male hairless rats were used to evaluate the penetration of MB into hair follicles. After formulation application, MB diffusion was induced and skin biopsies were realized immediately, 2 and 26 hours after MB loaded microspheres application. MB fluorescence was observed with a microscope expanded for fluorescence microscopy.

RESULTS

Position of microspheres and MB diffusion was dependent on delay between microspheres application and harvest. Inside the skin, MB was seen exclusively in the hair follicle and the sebaceous glands. MB diffusion varied from 160+/-50 microm (2 hours after application) to 410+/-70 microm (26 hours after application). MB was also found in the sebaceous glands.

DISCUSSION

This study confirms that 5 micro m microspheres are optimally deposited deep within the pilosebaceous structure. In agreement with the literature, when microspheres are topically applied on the skin, they penetrate via a "lipid-rich channel" coating the hair follicles. MB is exclusively distributed in the hair follicles and their accessories.

CONCLUSION

This report presents evidence of MB pilosebaceous delivery through the use of microsphere formulation. This is obtained thanks to topical enhancement via the follicular route. This drug delivery system aims to transport MB into the pilosebaceous unit specifically and deeply. Various other applications could derive from this work. For example, such a method might be used to increase the therapeutic index of drugs directed at hair sebaceous gland disorders. Laser treatment of acne or laser hair removal could also benefit of this technique.

Liposomes: applications in medicine

Liposomes are spherical lipid bilayers from 50 nm to 1000 nm in diameter that serve as convenient delivery vehicles for biologically active compounds. The field of liposome research has expanded considerably over the last 30 years. It is now possible to engineer a wide range of liposomes varying in size, phospholipid composition and surface characteristics to suit the specific application for which they are intended. This paper gives an overview of the main advances in liposome research from a point of view of their applications in medicine. Aqueous contrast enhancing agents entrapped in liposomal carriers can be targeted to the liver and spleen and distinctions can be made between normal and tumorous tissue using computed tomography. Topical application of liposomes has great potential in dermatology. Liposomes have been used to deliver anticancer agents in order to reduce the toxic effects of the drugs when given alone or to increase the circulation time and effectiveness of the drugs. From the original concept of encapsulating hemoglobin in an inert shell, liposome-encapsulated hemoglobin (LEH) has evolved into a fluid proven to carry oxygen, capable of surviving for reasonable periods in the circulation and amenable to large-scale production. Liposomes may be used to target specific cells by attaching amino acid fragments such as antibodies or proteins or appropriate fragments that target specific receptor sites. Liposomal DNA delivery vectors and further enhancements in the forms of LPDI and LPDII are some of the safest and potentially most versatile transfer vectors used to date. DNA vaccination and improved efficiency of gene therapy are just a few of the upcoming applications of liposomes.

Gene therapy

With recent advances in molecular biology, the ability to transfer genes to patients is becoming a reality. Ongoing clinical trials using gene transfer techniques have illustrated the potential and pitfalls of this new therapeutic modality for the treatment of a wide variety of disorders. While these techniques are not currently a part of routine clinical practice, it is only a matter of time until some form of gene therapy is approved for general use in the clinic. This review highlights some of the basic methods used in current gene therapy protocols. The objective of this review is to familiarize practitioners with these concepts so they can more effectively follow the progress of this emerging technology and better inform their patients.

Bispecific MAb aided liposomal drug delivery

We have developed a new method for specifically delivering liposomal model drugs to tumor cells. Bispecific monoclonal antibodies (bsMAb) (174H.64 x anti-biotin) which can bind tumor-specific antigen and biotin were developed and characterized. Biotinylated stealth liposome loaded with model drug 99mTc-DTPA can bind to the biotin-binding arm of bsMAb. This targeted liposomal delivery strategy was tested in mouse KLN-205 squamous carcinoma model. bsMAbs were administered 24h in advance into tumor allograft bearing mice, which allow them to bind to tumor cells through the anti-tumor binding arm. After clearance of circulating bsMAb, biotinylated stealth liposomes were introduced to specifically bind to the tumor sites where bsMAb localized earlier. The results show that pretargeted bsMAb can enhance liposomal drug targeting by four times, 3.61% dose/g vs. 0.89% dose/g. This bsMAb/liposome strategy show the broad possibilities of selective delivery of cytotoxic drugs or genes to the specific targets.

Controls of hair follicle cycling

Nearly 50 years ago, Chase published a review of hair cycling in which he detailed hair growth in the mouse and integrated hair biology with the biology of his day. In this review we have used Chase as our model and tried to put the adult hair follicle growth cycle in perspective. We have tried to sketch the adult hair follicle cycle, as we know it today and what needs to be known. Above all, we hope that this work will serve as an introduction to basic biologists who are looking for a defined biological system that illustrates many of the challenges of modern biology: cell differentiation, epithelial-mesenchymal interactions, stem cell biology, pattern formation, apoptosis, cell and organ growth cycles, and pigmentation. The most important theme in studying the cycling hair follicle is that the follicle is a regenerating system. By traversing the phases of the cycle (growth, regression, resting, shedding, then growth again), the follicle demonstrates the unusual ability to completely regenerate itself. The basis for this regeneration rests in the unique follicular epithelial and mesenchymal components and their interactions. Recently, some of the molecular signals making up these interactions have been defined. They involve gene families also found in other regenerating systems such as fibroblast growth factor, transforming growth factor-beta, Wnt pathway, Sonic hedgehog, neurotrophins, and homeobox. For the immediate future, our challenge is to define the molecular basis for hair follicle growth control, to regenerate a mature hair follicle in vitro from defined populations, and to offer real solutions to our patients' problems.

Hair on a gene string: recent advances in understanding the molecular genetics of hair loss

The hair follicle is finally, after remaining a mystery for many years, beginning to yield some of its molecular secrets. The past decade has seen unprecedented and ever quickening advances in understanding the molecular genetics of the many single gene disorders, which have alopecia as a major feature. This article reviews recent novel clinical and experimental observations, which have shed new light on the basic molecular mechanisms underlying hair morphogenesis, differentiation, keratinization and cycling. We consider recent progress in understanding structural hair defects and complex traits and consider where future developments are likely to occur.

Hair follicle apoptosis and Bcl-2

Hair follicle (HF) morphogenesis and cycling are characterized by a tightly controlled balance of proliferation, differentiation and apoptosis. The members of the bcl-2 family of proto-oncogenes are important key players in the apoptosis control machinery of most cell types. Bcl-2, an apoptosis inhibitor, and Bax, an apoptosis promoter, show tightly regulated, hair cycle-dependent expression patterns: during catagen, the distal ORS of the HF remains strongly positive for Bcl-2 and Bax; in contrast, the proximal epithelial part of the HF loses most Bcl-2 expression while it remains strongly positive for Bax. In Bcl-2 null mice, skin becomes markedly hypopigmented during the first postnatal anagen probably due to increased melanocyte apoptosis. Reportedly, these mice also show a retardation of the first anagen development after birth. Transgenic mice overexpressing Bcl-2 under the control of the keratin-1 promoter display multifocal epidermal hyperplasia and aberrant expression of keratin-6, while alterations of HF cycling have not been investigated. Surprisingly, Bcl-2 overexpression under the control of the keratin-14 promoter leads to accelerated catagen progression and increased chemotherapy-induced apoptosis, HF dystrophy and alopecia. Transgenic mice overexpressing Bcl-X(L), another anti-apoptotic bcl-2 family member, under the control of the K14 promoter, reportedly also display accelerated catagen development. These and other Bcl-2 transgenic and null mice are now available to further dissect the as yet unclear, and likely complex, role of Bcl-2 in HF growth and pigmentation.