Topical Pioglitazone Nanoformulation for the Treatment of Atopic Dermatitis: Design, Characterization and Efficacy in Hairless Mouse Model

Topical delivery of baricitinib-impregnated nanoemulgel: a promising platform for inhibition of JAK -STAT pathway for the effective management of atopic dermatitis

Baricitinib, an inhibitor of Janus kinase 1/2 receptors majorly involved in the dysregulation of immune responses in atopic dermatitis, is currently approved for managing atopic dermatitis in Europe. The delivery of baricitinib through oral route is associated to several adverse effects due to off-target effects. Therefore, the current study is aimed at formulation of baricitinib loaded nanoemulgel for evaluation of topical delivery potential in the treatment of atopic dermatitis. The baricitinib-loaded nanoemulsions (0.05 and 0.1% w/w) revealed an average globule size of 162.86 ± 0.37 and 173.66 ± 4.88 nm respectively with narrow PDI. The optimized batch of baricitinib nanoemulsion was converted to nanoemulgel by the addition of the mixture of gel bases SEPINEO™ DERM and SEPINEO™ P 600 along with propylene glycol, resulting in pseudoplastic shear thinning behaviour. The optimized nanoemulgels have shown prominent retention of baricitinib in the skin along with permeation. The skin distribution study of coumarin-6 loaded nanoemulgel demonstrated high fluorescence in the epidermal layer. The western blot analysis revealed significant inhibition of phosphorylated signal transducers and activators of transcriptions 1 (##p < 0.01) and 3 (#p < 0.05) by application of 0.05 and 0.1% baricitinib nanoemulgel. The baricitinib nanoemulgels have shown anti-inflammatory activity by significantly reducing expressions of various inflammatory markers. Histopathological analysis of skin tissues treated with baricitinib nanoemulgel has demonstrated a marked reduction in acanthosis, hyperkeratosis, and intact outer epidermis. These results supported the potential role of baricitinib-loaded nanoemulgel in reducing the inflammation and disease severity associated with atopic dermatitis.

Caspofungin formulations for buccal and sublingual mucosae anti-fungal infections: physicochemical characterization, rheological analysis, release and ex vivo permeability profiles

AIM

Oral candidiasis is often challenging due to limited effectiveness of topical treatments. This study aimed to develop novel caspofungin formulations for administration onto the oral mucosa to enhance drug retention and efficacy.

METHOD

Five caspofungin (2%, w/v) formulations were developed to assess their permeability, retention and mucoadhesiveness. Ex vivo permeability assays were performed on buccal and sublingual mucosae, and histological analyses conducted to evaluate tissue tolerance.

RESULTS

Formulation composed of chitosan demonstrated the highest retention in both buccal (5183.24 ± 587.32 µg/cm2) and sublingual (1090.72 ± 110.26 µg/cm2) mucosae. Other formulations exhibited significantly lower retention, ranging from 7.53 ± 0.81 to 1852.10 ± 193.24 µg/cm2 in buccal mucosa and 1.64 ± 0.14 to 317.74 ± 31.78 µg/cm2 in sublingual mucosa. Chitosan-based formulation exhibited the highest mucoadhesive strength, with values of 5179.05 ± 31.99 mN/cm2 for buccal and 7026.10 ± 123.41 mN/cm2 for sublingual mucosae, and also superior extensibility, which facilitates application in the oral cavity. All formulations showed antifungal activity against Candida spp., and histological analyses revealed minor epithelial alterations.

CONCLUSION

The developed formulations offer distinct advantages for treating oral candidiasis, with chitosan formulation emerging as the most promising due to its superior retention, mucoadhesion force, and spreadability, making it a potential candidate for further clinical investigation.

High mobility group box 1 cytokine targeted topical delivery of resveratrol embedded nanoemulgel for the management of atopic dermatitis

Resveratrol is a polyphenolic compound showing anti-inflammatory activity by inhibition of high mobility group box 1 cytokine responsible for the activation of nuclear factor-κB pathway in atopic dermatitis. To evaluate the efficacy of resveratrol through topical route we have developed resveratrol-loaded nanoemulgel for the effective management of atopic dermatitis in mice model. The resveratrol-loaded nanoemulsion (0.5%, 0.75% and 1% w/w) was optimized by spontaneous nano-emulsification. The optimized resveratrol-loaded nanoemulsions showed average globule size in the 180-230 nm range and found to be monodispersed. The resveratrol nanoemulgel was prepared with a SEPINEO™ P 600 gel base and propylene glycol. Ex vivo permeation and retention study resulted in significantly higher skin retention of resveratrol from resveratrol-loaded nanoemulgel than free resveratrol-loaded gel. Preclinical efficacy of resveratrol nanoemulgel displayed promising therapeutic outcomes where, western blotting of skin tissues disclosed a significant reduction in the relative expression of high mobility group box 1, the receptor for advanced glycation end products, toll-like receptor-4 and phosphorylated nuclear factor-κB. Further, real-time polymerase chain reaction also disclosed a significant reduction in pro-inflammatory cytokines such as thymic stromal lymphopoietin, interleukin-4, interleukin-13, interleukin-31, tumor necrosis factor-α and interleukin-6. The histopathological examination of skin sections showed improvement in the skin condition. Collectively, the findings from our study showcased the significant improvement in the atopic dermatitis skin condition in mice model after topical application of resveratrol loaded nanoemulgel.

Recent Advances in Nanocarrier-based Approaches to Atopic Dermatitis and Emerging Trends in Drug Development and Design

Atopic dermatitis (AD), commonly known as Eczema, is a non-communicable skin condition that tends to become chronic. The deteriorating immunological abnormalities are marked by mild to severe erythema, severe itching, and recurrent eczematous lesions. Different pharmacological approaches are used to treat AD. The problem with commercial topical preparations lies in the limitation of skin atrophy, systemic side effects, and burning sensation that decreases patient compliance. The carrier-based system promises to eliminate these shortcomings; thus, a novel approach to treating AD is required. Liposomes, microemulsions, solid lipid nanoparticles (SLNs), nanoemulsions, etc., have been developed recently to address this ailment. Despite extensive research in the development method and various techniques, it has been challenging to demonstrate the commercial feasibility of these carrier- based systems, which illustrates a gap among the different research areas. Further, different soft wares and other tools have proliferated among biochemists as part of a cooperative approach to drug discovery. It is crucial in designing, developing, and analyzing processes in the pharmaceutical industry and is widely used to reduce costs, accelerate the development of biologically innovative active ingredients, and shorten the development time. This review sheds light on the compilation of extensive efforts to combat this disease, the product development processes, commercial products along with patents in this regard, numerous options for each step of computer-aided drug design, including in silico pharmacokinetics, pharmacodynamics, and toxicity screening or predictions that are important in finding the drug-like compounds.

Challenges of current treatment and exploring the future prospects of nanoformulations for treatment of atopic dermatitis

Atopic dermatitis (AD) is a predominant and deteriorating chronic inflammation of the skin, categorized by a burning sensation and eczematous lesions in diverse portions of the body. The treatment of AD is exclusively focused to limit the itching, reduce inflammation, and repair the breached barrier of the skin. Several therapeutic agents for the treatment and management of AD have been reported and are in use in clinics. However, the topical treatment of AD has been an unswerving challenge for the medical fraternity owing to the impaired skin barrier function in this chronic skin condition. To surmount the problems of conventional drug delivery systems, numerous nanotechnology-based formulations are emerging as alternative new modalities for AD. Latter enhances the bioavailability and delivery to the target disease site, improves drug permeation and therapeutic efficacy with reduced systemic and off-target side effects, and thus improves patient health and promotes compliance. This review aims to describe the various pathophysiological events involved in the occurrence of AD, current challenges in treatment, evidence of molecular markers of AD and its management, combinatorial treatment options, and the intervention of nanotechnology-based formulations for AD therapeutics.

Therapeutic Applications of Essential Oils from Native and Cultivated Ecuadorian Plants: Cutaneous Candidiasis and Dermal Anti-Inflammatory Activity

Essential oils are a complex mixture of aromatic substances whose pharmacological actions, including antimicrobial, antioxidant, anticancer, and anti-inflammatory activities, have been widely reported. This study aimed to evaluate the anti-Candida and dermal anti-inflammatory activity of essential oils from native and cultivated Ecuadorian plants. Essential oils from Bursera graveolens, Dacryodes peruviana, Mespilodaphne quixos, and Melaleuca armillaris were isolated by hydrodistillation and were characterized physically and chemically. Its tolerance was analyzed by in vitro and in vivo studies. The antifungal activity was studied against Candida albicans, Candida glabrata, and Candida parapsilosis, whereas the anti-inflammatory effect was evaluated by a mouse ear edema model. The main compounds were limonene, α-phellandrene, (E)-methyl cinnamate, and 1,8-cineole, respectively. All essential oils showed high tolerability for skin application, antifungal activity against the three Candida strains, and anti-inflammatory efficacy by decreasing edema and overexpression of pro-inflammatory cytokines. Dacryodes peruviana essential oil showed the highest antifungal activity. On the other hand, Dacryodes peruviana and Melaleuca armillaris showed the greatest anti-inflammatory potential, decreasing edema by 53.3% and 65.25%, respectively, and inhibiting the overexpression of TNF-α, IL-8, IL-17A, and IL-23. The results suggest that these essential oils could be used as alternative therapies in the treatment of both cutaneous candidiasis and dermal inflammation.

Recent Trends in Nanocarriers for the Management of Atopic Dermatitis

BACKGROUND

Atopic dermatitis (AD) is a pruritic inflammatory skin condition with increasing global prevalence, almost affecting 15% to 30% of children and 5% of adults. AD results due to a complex interaction between the impaired skin barrier function, allergens, and immunological cells. Topical corticosteroids or calcineurin inhibitors in the form of creams or ointments are the mainstay of therapy, but they have low skin penetration and skin barrier repair efficiency.

OBJECTIVE

The above limitations of conventional dosage forms have motivated the development of nanoformulations of drugs for improved penetration and deposition in the skin for better management of AD.

METHODS

Databases, such as Pubmed, Elsevier, and Google Scholar, were reviewed for the investigations or reviews published related to the title.

RESULTS

The present review discusses the advantages of nanoformulations for the management of AD. Further, it also discusses the various types of topically investigated nanoformulations, i.e., polymeric nanoparticles, inorganic nanoparticles, solid lipid nanoparticles, liposomes, ethosomes, transfersomes, cubosomes, and nanoemulsion for the management of atopic dermatitis. In addition, it also discusses advancements in nanoformulations, such as nanofibres, nanosponges, micelles, and nanoformulations embedded textiles development for the management of AD.

CONCLUSION

The nanoformulations of drugs can be a better alternative for the topical management of AD with enhanced skin penetration and deposition of drugs with reduced systemic side effects and better patient compliance.

Characterization and In Vivo Anti-Inflammatory Efficacy of Copal (Dacryodes peruviana (Loes.) H.J. Lam) Essential Oil

Essential oils are natural aromatic substances that contain complex mixtures of many volatile compounds frequently used in pharmaceutical and cosmetic industries. Dacryodes peruviana (Loes.) H.J. Lam is a native species from Ecuador whose anti-inflammatory activity has not been previously reported, thus the aim of this study was to evaluate the anti-inflammatory activity of D. peruviana essential oil. To that end, essential oil from D. peruviana fruits was isolated by hydrodistillation and characterized physically and chemically. The tolerance of the essential oil was analyzed by cytotoxicity studies using human keratinocytes. The anti-inflammatory activity was evaluated by an arachidonic acid-induced edema model in mouse ear. The predominant compounds in D. peruviana essential oil were α-phellandrene, limonene, and α-pinene, with the three compounds reaching approximately 83% of the total composition. Tolerance studies showed high biocompatibility of this essential oil with human keratinocytes. In vivo studies demonstrated a moisturizing effect and an alleviation of several events occurred during the inflammatory process after topical treatment with D. peruviana essential oil such as decline in skin edema; reduction in leukocytic infiltrate; and decrease in inflammatory cytokines TNFα, IL-8, IL-17A, and IL-23. Therefore, this essential oil could be an attractive treatment for skin inflammation.

Comparative Study of Donepezil-Loaded Formulations for the Treatment of Alzheimer's Disease by Nasal Administration

Alzheimer's disease is characterized by a progressive deterioration of neurons resulting in a steady loss of cognitive functions and memory. Many treatments encounter the challenge of overcoming the blood-brain barrier, thus the intranasal route is a non-invasive effective alternative that enhances the drug delivery in the target organ-the brain-and reduces the side effects associated with systemic administration. This study aimed at developing intranasal gels of donepezil as an approach to Alzheimer's disease. Three different gels were elaborated and characterized in terms of pH, morphology, gelation temperature, rheology, and swelling. An in vitro release study and an ex vivo permeation in porcine nasal mucosa were conducted on Franz diffusion cells. The tolerability of the formulations was determined by the cytotoxicity in human nasal cells RPMI 2650. Results showed that pluronic gels exhibit the higher release rate and enhanced permeation compared to chitosan gel. Moreover, the combination of Pluronic F-127 and Transcutol® P exerted a synergic effect on the permeation of donepezil through the nasal mucosa. The resulting gels showed suitable tolerance in the RPMI 2650 cell line and physicochemical characteristics for intranasal delivery, and thus gel formulations administered by nasal mucosa could be an alternative strategy to improve the bioavailability of donepezil.

Development and Optimization of Nigella sativa Nanoemulsion Loaded with Pioglitazone for Hypoglycemic Effect

Diabetes mellitus (DM) is a metabolic disorder associated with an increased blood glucose level. The world health burden of DM has increased as a result of numerous causes that necessitates suitable treatment. Pioglitazone (PGZ) is a generally prescribed medication for managing type II diabetes. However, its low solubility creates complications for its formulation. Therefore, the aim of the current study was to incorporate PGZ into a nanoemulsion (NE) formulation prepared with Nigella sativa oil (NSO) to boost the action of PGZ. To our knowledge, no previous study has addressed the combination and synergistic effect of PGZ and NSO as a hypoglycemic NE formulation intended for oral administration. An experiment was designed to test several PGZ-loaded NE formulations, varying factors such as NSO, surfactant and co-surfactant concentrations. These factors were investigated for their influence on responses including particle size and in vitro release. An optimized PGZ-loaded NE was selected and examined for its morphology, kinetic activity and stability. Further, the anti-diabetic effect of the optimized formulation was evaluated using diabetically induced rats. The optimized formula exhibited a good particle size of 167.1 nm and in vitro release of 89.5%. A kinetic study revealed that the drug release followed the Korsmeyer–Peppas mechanism. Additionally, the PGZ-loaded NE formulation was found to be stable, showing non-significant variation in the evaluated parameters when stored at 4 and 25 °C for a period of 3 months. In vivo investigation of the PGZ-loaded NE formulation showed a significant reduction in blood glucose level, which appeared to be enhanced by the presence of NSO. In conclusion, NS-NE could be a promising nanocarrier for enhancing the hypoglycemic effect of PGZ.

Old drugs, new tricks: Emerging role of drug repurposing in the management of atopic dermatitis

Atopic dermatitis is a chronic recurring pruritic inflammatory skin disease manifested by increased pro-inflammatory mediators which lead to dry, thickened, cracked, scaly skin. The current treatment options for atopic dermatitis management comprise drawbacks and leave unmet effective clinical needs. So, the approach for repurposing existing drugs for atopic dermatitis management may potentially overcome these unmet needs. Diseases that share the common pathophysiological pathways with atopic dermatitis can serve as a foundation for the repurposing of drugs. Drugs used in the management of cancer, rheumatoid arthritis, and other immune-mediated diseases such as psoriasis are under investigation to know the potential in atopic dermatitis management by utilizing repurposing strategies for a novel therapeutic indication. This review mainly envisages the probable repurposing of drugs for the management of atopic dermatitis disease; the barriers and regulatory aspects involved in the repurposing of existing drugs.

Development of Peptide Targeted PLGA-PEGylated Nanoparticles Loading Licochalcone-A for Ocular Inflammation

Licochalcone-A is a natural compound with anti-inflammatory properties. However, it possesses low water solubility, making its application for the treatment of ocular inflammation difficult. To overcome this drawback, biodegradable nanoparticles incorporating Licochalcone-A have been developed. Additionally, to avoid fast clearance and increase cellular internalization into the ocular tissues, PLGA nanoparticles have been functionalized using PEG and cell penetrating peptides (Tet-1 and B6). To optimize the formulations, a factorial design was carried out and short-term stability of the nanoparticles was studied. Moreover, morphology was also observed by transmission electron microcopy and in vitro drug release was carried out. Ocular tolerance of the formulations was ensured in vitro and in vivo and anti-inflammatory therapeutic efficacy was also assessed. Surface functionalized nanoparticles loading Licochalcone-A were developed with an average size below 200 nm, a positive surface charge, and a monodisperse population. The formulations were non-irritant and showed a prolonged Licochalcone-A release. Despite the fact that both Licochalcone-A Tet-1 and B6 functionalized nanoparticles demonstrated to be suitable for the treatment of ocular inflammation, B6 targeted nanoparticles provided greater therapeutic efficacy in in vivo assays.

Preparation and Evaluation of Polyvinylpyrrolidone Electrospun Nanofiber Patches of Pioglitazone for the Treatment of Atopic Dermatitis

Nanofibers have many promising biomedical applications. They can be used for designing transdermal and dermal drug delivery systems. This project aimed to prepare and characterize polyvinylpyrrolidone-based nanofibers as a dermal and transdermal drug delivery system using pioglitazone. Pioglitazone is an oral antidiabetic drug. In addition, it can act as an inflammatory process modulator, making it a good candidate for managing different skin inflammatory conditions such as atopic dermatitis, skin ulcers, and diabetic foot wound healing. Several nanofiber formulations were prepared using the electrospinning method at different drug loadings, polyvinylpyrrolidone concentrations, and flow rates. A cast film with the exact composition of selected nanofiber formulations was prepared as a control. Nanofibers were characterized using a scanning electron microscope to calculate the diameter. Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction were performed for physical and biochemical characterizations. In vitro release, drug loading efficiency, and swelling studies were performed. Ex vivo permeation studies were performed using Franz diffusion cells with or without applying a solid microneedle roller. Round uniform nanofibers with a smooth surface were obtained. The diameter of nanofibers was affected by the drug loading and polymer concentration. Fourier-transform infrared spectra showed a potential physical interaction between the drug and the polymer. According to X-ray diffraction, pioglitazone existed in an amorphous form in prepared nanofibers, with partial crystallinity in the casted film. Nanofibers showed a higher swelling rate compared to the casted film. The drug dissolution rate for nanofibers was 2.3-folds higher than the casted films. The polymer concentration affected the drug dissolution rate for nanofibers; however, drug loading and flow rate did not affect the drug dissolution rate for nanofibers. The application of solid microneedles slightly enhances the total amount of drug permeation. However, it did not affect the flux of the drug through the separated epidermis layer for pioglitazone. The drug permeation flux in nanofibers was approximately five times higher than the flux of the casted film. It was observed that pioglitazone is highly retained in skin layers. Graphical abstract.

Emerging topical drug delivery approaches for the treatment of Atopic dermatitis

BACKGROUND

Atopic dermatitis is a chronic, relapsing skin inflammation disease that generally affects 20% of children and 1-3% of adults. It is characterized by pruritus, inflammatory skin lesions, and skin barrier defect. The pillar treatment is topical therapies that have shown great adherence and incredible results in alleviating symptoms of atopic dermatitis. Topical corticosteroids and calcineurin inhibitors have shown improvement in the symptoms of atopic dermatitis but have certain side effects. There is need to develop new therapies or novel drug delivery approaches which can overcome drawbacks of the conventional formulation and increase the therapeutic efficacy.

AIM

The scope of this review is to describe the new topical therapies including phosphodiesterase inhibitors, Janus kinase inhibitors, and nano-formulations such as nanoemulsion, polymeric and lipid nanoparticles, vesicular system, and micelles.

METHODS

The article reviews and discusses the published literature of the topical drug delivery approaches for treatment of Atopic dermatitis.

RESULTS

The reported literature highlighted the benefits of novel topical formulations exhibiting targeted drug delivery, better penetration, enhanced therapeutic efficacy, and overcome systemic side effects.

CONCLUSION

Literature indicated that the new therapies and novel drug delivery approaches found to be the therapeutically more effective in increasing the efficacy of drugs and reducing the side effects in comparison with the conventional treatments for Atopic dermatitis. This has provided a way to modify and develop more such formulations for dermal delivery.

Development of a Topical Amphotericin B and Bursera graveolens Essential Oil-Loaded Gel for the Treatment of Dermal Candidiasis

The higher molecular weight and low solubility of amphotericin B (AmB) hinders its topical administration. The aim of this study was to incorporate Bursera graveolens essential oil into an AmB topical gel (AmB + BGEO gel) in order to promote the diffusion of the drug through the skin in the treatment of cutaneous candidiasis. AmB + BGEO gel formulation was determined using a factorial experiment. Physical and chemical parameters, stability, in vitro release profile and ex vivo permeation in human skin were evaluated. In vitro antimicrobial activity was studied using strains of C. albicans, C. glabrata and C. parapsilosis. The tolerability was evaluated using in vitro and in vivo models. AmB + BGEO gel presented appropriate characteristics for topical administration, including pH of 5.85, pseudoplastic behavior, optimal extensibility, as well as high stability and acceptable tolerability. In vitro release studies showed that the formulation releases the drug following a Boltzmann sigmoidal model. Finally, AmB + BGEO gel exhibited higher amount of drug retained inside the skin and lower Minimum Inhibitory Concentration than a formulation sans essential oil. Therefore, these results suggest that the incorporation of B. graveolens essential oil in the formulation could be used as strategy to promote a local effect in the treatment of cutaneous candidiasis.

Recent Advances in Nanomaterials for Dermal and Transdermal Applications

The stratum corneum, the most superficial layer of the skin, protects the body against environmental hazards and presents a highly selective barrier for the passage of drugs and cosmetic products deeper into the skin and across the skin. Nanomaterials can effectively increase the permeation of active molecules across the stratum corneum and enable their penetration into deeper skin layers, often by interacting with the skin and creating the distinct sites with elevated local concentration, acting as reservoirs. The flux of the molecules from these reservoirs can be either limited to the underlying skin layers (for topical drug and cosmeceutical delivery) or extended across all the sublayers of the epidermis to the blood vessels of the dermis (for transdermal delivery). The type of the nanocarrier and the physicochemical nature of the active substance are among the factors that determine the final skin permeation pattern and the stability of the penetrant in the cutaneous environment. The most widely employed types of nanomaterials for dermal and transdermal applications include solid lipid nanoparticles, nanovesicular carriers, microemulsions, nanoemulsions, and polymeric nanoparticles. The recent advances in the area of nanomaterial-assisted dermal and transdermal delivery are highlighted in this review.

The Cross-Talk Between Atopic Dermatitis and Diabetes Mellitus: A Meta-Analysis

INTRODUCTION

Atopic dermatitis (AD) is associated with various systemic diseases. However, its association with diabetes mellitus (DM) was discussed controversially. Few researchers reviewed the association of these two common morbid disorders. This meta-analysis aimed to assess the relationship between AD and DM.

METHODS

We systematically searched PubMed including Epub and ahead of print (198 articles identified) and Cochrane (13 articles) databases. The searching engine was set to include case-control, prospective and retrospective cohorts, and cross-sectional studies from the first published up to February 12, 2021. Two hundred and eleven were identified, eighteen full texts were screened; of them, six were included in the final meta-analysis. The keywords used were AD, diabetes mellitus, type 1 diabetes, and type 2 diabetes. A datasheet was used to record the author's name, year of publication, country and type of the studies, number of events, and total number in the two arms (patients and controls).

RESULTS

Out of the 211 references identified, six studies were pooled to test the association between diabetes mellitus and AD. The studies showed that AD is lower among patients with DM, odds ratio, 0.69, 95% CI, and 0.67-0.72. No heterogeneity was observed (Chi-Square, 4.12, degree of freedom (df.)= 5, and I² = 0%, P-value), 0.53 and P-value for overall effect, <0.001. The included studies were published in Europe (five) and Canada (one study) and included 162,882 patients and 12,164 events, four of the studied articles were case-control studies, one retrospective, and one cross-sectional.

CONCLUSION

AD was lower among patients with DM compared to their counterparts without the disease. Further studies focusing on the genetic and environmental factors linking AD and diabetes are needed.

Facial Fat Fitness: A New Paradigm to Understand Facial Aging and Aesthetics

Traditionally, facial adipose tissue has been perceived and treated as a homogenous volume-occupying subcutaneous depot. However, recent research from across disciplines is converging to reveal a far more anatomically organized and functionally dynamic role of facial adipose tissue. In this narrative review, we will discuss new insights into adipocyte function and facial adipose anatomy that have far-reaching implications for the practice of aesthetic facial plastic surgery. These concepts are synthesized into a "facial fat fitness" model which can be used to explain clinical observations in facial aging and aesthetic surgery. Fat fitness relates to the quality of facial adipose tissue, as opposed to quantity, and describes whether adipose tissue is in a predominantly healthy hyperplastic or unhealthy hypertrophic state. Fat fitness is modulated by lifestyle factors, and may be impacted positively or negatively by facial aesthetic treatments. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Nanocarriers for treatment of dermatological diseases: Principle, perspective and practices

Skin diseases are the fourth leading non-fatal skin conditions that act as a burden and affect the world economy globally. This condition affects the quality of a patient's life and has a pronounced impact on both their physical and mental state. Treatment of these skin conditions with conventional approaches shows a lack of efficacy, long treatment duration, recurrence of conditions, systemic side effects, etc., due to improper drug delivery. However, these pitfalls can be overcome with the applications of nanomedicine-based approaches that provide efficient site-specific drug delivery at the target site. These nanomedicine-based strategies are evolved as potential treatment opportunities in the form of nanocarriers such as polymeric and lipidic nanocarriers, nanoemulsions along with emerging others viz. carbon nanotubes for dermatological treatment. The current review focuses on challenges faced by the existing conventional treatments along with the topical therapeutic perspective of nanocarriers in treating various skin diseases. A total of 213 articles have been reviewed and the application of different nanocarriers in treating various skin diseases has been explained in detail through case studies of previously published research works. The toxicity related aspects of nanocarriers are also discussed.

Trends in nanoformulations for atopic dermatitis treatment

INTRODUCTION

Immunological skin dysfunctions trigger the synthesis and release of inflammatory cytokines, which induce recurrent skin inflammation associated with chronic itching, inefficient barrier behavior, and reduced skin hydration. These features characterize a multifactorial chronic inflammatory disease atopic dermatitis (AD). AD therapy includes anti-inflammatory drugs and immunosuppressors as well as non-pharmacological alternatives such as emollients, moisturizers, and lipids (ceramides, phospholipids) for modulating the skin hydration and the barrier repair. However, these treatments are inconvenient with low drug skin penetration and insufficient maintenance on the application site.

AREAS COVERED

Nanotechnology-based therapies can be a great strategy to overcome these limitations. Considering the particular skin morphological organization, SC lipid matrix composition, and immunological functions/features related to nanocarriers, this review focuses on recent developments of nanoparticulate systems (polymeric, lipid-based, inorganic) as parent or hybrid systems including their chemical composition, physico-chemical and biopharmaceutical properties, and differential characteristics that evaluate them as new effective drug-delivery systems for AD treatment.

EXPERT OPINION

Despite the several innovative formulations, research in nanotechnology-based carriers should address specific aspects such as the use of moisturizers associated to pharmacological therapies, toxicity studies, scale-up production processes and the nanocarrier influence on immunological response. These approaches will help researchers choose the most appropriate nanocarrier system and widen nanomedicine applications and commercialization.