Elastic and Ultradeformable Liposomes for Transdermal Delivery of Active Pharmaceutical Ingredients (APIs)

In vivo reduction of skin inflammation using ferulic acid-loaded lipid vesicles derived from Brewer's spent grain

Breweŕs spent grain (BSG) is the main by-product of the brewing industry, and due to its rapid decomposition, it generates serious environmental problems such as malodors and greenhouse gases emissions. On the other hand, this lignocellulosic compound contains a large number of antioxidants, being ferulic acid (FA) the most abundant. FA is a powerful antioxidant molecule that has demonstrated significant protective effects on key components of the skin, including keratinocytes, fibroblasts, collagen, and elastin. FA inhibits melanogenesis, promotes angiogenesis and accelerates the wound healing although its use is limited by its rapid oxidation. In this study, different hydrolysis treatments (chemical, enzymatic and hydrothermal) were performed on BSG to obtain FA. Herein FA-loaded ultradeformable liposomes (ULs) were designed to improve their stability and in vivo performance. These nanosystems allow FA permeability through human skin, as proven by an ex vivo skin permeability assay using Franz diffusion cells. The toxicity and anti-inflammatory activity of the formulation has been investigated. The free form and 100 nm FA_ULs were evaluated. Cell viability was dose-dependent and provided optimal results for the treatment of inflammatory skin conditions in an in vivo Oxazolone-induced Delayed Type Hypersensitivity model using Swiss CD1 mice, demonstrated by the reduction of the inflammatory cytokines expression, ear thickness, bioluminescence and histological evaluation. These results pave the way for FA-based treatments of skin and inflammatory conditions.

Improving Skin Cancer Treatment by Dual Drug Co-Encapsulation into Liposomal Systems-An Integrated Approach towards Anticancer Synergism and Targeted Delivery

Skin cancer is a high-incidence complex disease, representing a significant challenge to public health, with conventional treatments often having limited efficacy and severe side effects. Nanocarrier-based systems provide a controlled, targeted, and efficacious methodology for the delivery of therapeutic molecules, leading to enhanced therapeutic efficacy, the protection of active molecules from degradation, and reduced adverse effects. These features are even more relevant in dual-loaded nanosystems, with the encapsulated drug molecules leading to synergistic antitumor effects. This review examines the potential of improving the treatment of skin cancer through dual-loaded liposomal systems. The performed analysis focused on the characterization of the developed liposomal formulations' particle size, polydispersity index, zeta potential, encapsulation efficiency, drug release, and in vitro and/or in vivo therapeutic efficacy and safety. The combination of therapeutic agents such as doxorubicin, 5-fluorouracil, paclitaxel, cetuximab, celecoxib, curcumin, resveratrol, quercetin, bufalin, hispolon, ceramide, DNA, STAT3 siRNA, Bcl-xl siRNA, Aurora-A inhibitor XY-4, 1-Methyl-tryptophan, and cytosine-phosphate-guanosine anionic peptide led to increased and targeted anticancer effects, having relevant complementary effects as well, including antioxidant, anti-inflammatory, and immunomodulatory activities, all relevant in skin cancer pathophysiology. The substantial potential of co-loaded liposomal systems as highly promising for advancing skin cancer treatment is demonstrated.

Topical Delivery of Dual Loaded Nano-Transfersomes Mediated Chemo-Photodynamic Therapy against Melanoma via Inducing Cell Cycle Arrest and Apoptosis

Melanoma is a malignant skin cancer associated with high mortality rates and drug resistance, posing a significant threat to human health. The combination of chemotherapy and photodynamic therapy (PDT) represents a promising strategy to enhance antitumor efficacy through synergistic anti-cancer effects. Topical delivery of chemotherapeutic drugs and photosensitizers (PS) offers a non-invasive and safe way to treat melanoma. However, the effectiveness of these treatments is often hindered by challenges such as limited skin permeability and instability of the PS. In this study, transfersomes (TFS) were designed to facilitate transdermal delivery of the chemotherapeutic drug 5-Fluorouracil (5-FU) and the PS Imperatorin (IMP) for combined chemo-photodynamic therapy for melanoma. The cytotoxic and phototoxic effects of TFS-mediated PDT (TFS-UVA) were investigated in A375 cells and nude mice. The study also demonstrated that TFS-UVA generated intracellular ROS, induced G2/ M phase cell cycle arrest, and promoted cell apoptosis. In conclusion, this study indicated that 5-FU/ IMP-TFS serves as an effective transdermal therapeutic strategy for chemo-PDT in treating melanoma.

Advancing psoriasis drug delivery through topical liposomes

Psoriasis, recognized as a chronic inflammatory skin disorder, disrupts immune system functionality. Global estimates by the World Psoriasis Day consortium indicate its impact on approximately 130 million people, constituting 4 to 5 percent of the worldwide population. Conventional drug delivery systems, mainly designed to alleviate psoriasis symptoms, fall short in achieving targeted action and optimal bioavailability due to inherent challenges such as the drug's brief half-life, instability, and a deficiency in ensuring both safety and efficacy. Liposomes, employed in drug delivery systems, emerge as highly promising carriers for augmenting the therapeutic efficacy of topically applied drugs. These small unilamellar vesicles demonstrate enhanced penetration capabilities, facilitating drug delivery through the stratum corneum layer of skin. This comprehensive review article illuminates diverse facets of liposomes as a promising drug delivery system to treat psoriasis. Addressing various aspects such as formulation strategies, encapsulation techniques, and targeted delivery, the review underscores the potential of liposomes in enhancing the efficacy and specificity of psoriasis treatments.

Strategies to Improve the Transdermal Delivery of Poorly Water-Soluble Non-Steroidal Anti-Inflammatory Drugs

The transdermal delivery of non-steroidal anti-inflammatory drugs (NSAIDs) has the potential to overcome some of the major disadvantages relating to oral NSAID usage, such as gastrointestinal adverse events and compliance. However, the poor solubility of many of the newer NSAIDs creates challenges in incorporating the drugs into formulations suitable for application to skin and may limit transdermal permeation, particularly if the goal is therapeutic systemic drug concentrations. This review is an overview of the various strategies used to increase the solubility of poorly soluble NSAIDs and enhance their permeation through skin, such as the modification of the vehicle, the modification of or bypassing the barrier function of the skin, and using advanced nano-sized formulations. Furthermore, the simple yet highly versatile microemulsion system has been found to be a cost-effective and highly successful technology to deliver poorly water-soluble NSAIDs.

Elastic Liposomes Containing Calcium/Magnesium Ferrite Nanoparticles Coupled with Gold Nanorods for Application in Photothermal Therapy

This work reports on the design, development, and characterization of novel magneto-plasmonic elastic liposomes (MPELs) of DPPC:SP80 (85:15) containing Mg0.75Ca0.25Fe2O4 nanoparticles coupled with gold nanorods, for topical application of photothermal therapy (PTT). Both magnetic and plasmonic components were characterized regarding their structural, morphological, magnetic and photothermal properties. The magnetic nanoparticles display a cubic shape and a size (major axis) of 37 ± 3 nm, while the longitudinal and transverse sizes of the nanorods are 46 ± 7 nm and 12 ± 1.6 nm, respectively. A new methodology was employed to couple the magnetic and plasmonic nanostructures, using cysteine as bridge. The potential for photothermia was evaluated for the magnetic nanoparticles, gold nanorods and the coupled magnetic/plasmonic nanoparticles, which demonstrated a maximum temperature variation of 28.9 °C, 33.6 °C and 37.2 °C, respectively, during a 30 min NIR-laser irradiation of 1 mg/mL dispersions. Using fluorescence anisotropy studies, a phase transition temperature (Tm) of 35 °C was estimated for MPELs, which ensures an enhanced fluidity crucial for effective crossing of the skin layers. The photothermal potential of this novel nanostructure corresponds to a specific absorption rate (SAR) of 616.9 W/g and a maximum temperature increase of 33.5 °C. These findings point to the development of thermoelastic nanocarriers with suitable features to act as photothermal hyperthermia agents.

Development of nano-liposomal human growth hormone as a topical formulation for preventing uvb-induced skin damage

Due to its involvement in skin maintenance and repair, topical administration of recombinant human growth hormone (rhGH) is an interesting strategy for therapeutic purposes. We have formulated and characterized a topical rhGH-loaded liposomal formulation (rhGH-Lip) and evaluated its safety, biological activity, and preventive role against UVB-induced skin damage. The rhGH-Lip had an average size and zeta potential of 63 nm and -33 mV, respectively, with 70 % encapsulation efficiency. The formulation was stable at 4 °C for at least one year. The SDS-PAGE and circular dichroism results showed no structural alterations in rhGH upon encapsulation. In vitro, studies in HaCaT, HFFF-2, and Ba/F3-rhGHR cell lines confirmed the safety and biological activity of rhGH-Lip. Franz diffusion cell study showed increased rhGH skin permeation compared to free rhGH. Animal studies in nude mice showed that liposomal rhGH prevented UVB-induced epidermal hyperplasia, angiogenesis, wrinkle formation, and collagen loss, as well as improving skin moisture. The results of this study show that rhGH-Lip is a stable, safe, and effective skin delivery system and has potential as an anti-wrinkle formulation for topical application. This study also provides a new method for the topical delivery of proteins and merits further investigation.

Delivery Strategies for Colchicine as a Critical Dose Drug: Reducing Toxicity and Enhancing Efficacy

Colchicine (COL), a widely used natural drug, has potent anti-inflammatory effects; however, as a narrow therapeutic index drug, its clinical application is limited by its serious gastrointestinal adverse effects, and only oral formulations are currently marketed worldwide. Recent studies have shown that transdermal, injection, and oral drug delivery are the three main delivery strategies for COL. This article elaborates on the research progress of different delivery strategies in terms of toxicity reduction and efficacy enhancement, depicting that the transdermal drug delivery route can avoid the first-pass effect and the traumatic pain associated with the oral and injection routes, respectively. Therefore, such a dosage form holds a significant promise that requires the development of further research to investigate effective COL delivery formulations. In addition, the permeation-promoting technologies utilized for transdermal drug delivery systems are briefly discussed. This article is expected to provide scientific ideas and theoretical guidance for future research and the exploration of COL delivery strategies.

Deformable Vesicles with Edge Activators for the Transdermal Delivery of Non-Psychoactive Cannabinoids

BACKGROUND

Transdermal delivery of highly lipophilic molecules is challenging due to the strong barrier function of the skin. Vesicles with penetration enhancers are safe and efficient systems that could improve the transdermal delivery of non-psychoactive cannabinoids such as cannabidiol and desoxy-cannabidiol. In the last decades, research interest in desoxy-cannabidiol as a potent drug with anti-nociceptive properties has risen. Still, its scarce market availability poses a limit for both research and clinical applications. Therefore, it is necessary to improve the synthesis to produce sufficient amounts of desoxy-cannabidiol. Moreover, also the formulation aspects for this drug are challenging and require to be addressed to meet an efficient delivery to the patients.

OBJECTIVE

This work aimed to develop innovative phospholipid-based vesicles with propylene glycol (PG), oleic acid (OA), or limonene as edge activators, for the transdermal delivery of highly lipophilic drugs such as non-psychoactive cannabinoids. In particular, desoxy-cannabidiol was selected thanks to its anti-nociceptive activity, and its synthesis was improved enhancing the stereoselectivity of its synthon's production.

METHODS

Desoxy-cannabidiol was synthesized by Lewis acid-mediated condensation of p-mentha-2,8-dien- 1-ol and m-pentylphenol, improving the stereoselectivity of the first synthon's production. Transethosomes containing 20-50% w/w PG, 0.4-0.8% w/w OA, or 0.1-1% w/w limonene were optimized and loaded with cannabidiol or desoxy-cannabidiol (0.07-0.8% w/w, 0.6-7.0 mg/mL). Ex-vivo studies were performed to assess both the skin permeation and accumulation of the cannabinoids, as well as the penetration depth of fluorescein- loaded systems used as models.

RESULTS

An enantioselective bromination was added to the pathway, thus raising the production yield of pmentha- 2,8-dien-1-ol to 81% against 35%, and the overall yield of desoxy-cannabidiol synthesis from 12% to 48%. Optimized transethosomes containing 0.6 mg/mL cannabinoids were prepared with 1:10 PG:lipid weight ratio, 0.54 OA:lipid molar ratio, and 0.3 limonene:lipid molar ratio, showing good nanometric size (208 ± 20.8 nm - 321 ± 26.3 nm) and entrapment efficiency (> 80%). Ex-vivo tests showed both improved skin permeation rates of cannabinoids (up to 21.32 ± 4.27 μg/cm2 cannabidiol), and skin penetration (depth of fluorescein up to 240 μm, with PG).

CONCLUSION

Desoxy-cannabidiol was successfully produced at high yields, and formulated into transethosomes optimized for transdermal delivery. Loaded vesicles showed improved skin penetration of desoxy-cannabidiol, cannabidiol and a lipophilic probe. These results suggest the potential of these carriers for the transdermal delivery of highly lipophilic drugs.

Enhanced Transdermal Peptide-Modified Flexible Liposomes for Efficient Percutaneous Delivery of Chrysomycin A to Treat Subcutaneous Melanoma and Intradermal MRSA Infection

Superficial skin diseases, including skin infections and tumors, are common healthcare burdens. In this study, the in vivo activity of chrysomycin A (CA) is explored, and a transdermal liposomal CA formulation is further constructed for the simultaneous treatment of cutaneous melanoma and cutaneous methicillin-resistant Staphylococcus aureus (MRSA) infection. The prepared liposomes (TD-LP-CA) display a strong antitumor effect with an IC50 value of less than 0.1 µm in B16-F10 cells, suppress the proliferation of MRSA with a minimum inhibitory concentration (MIC) of 1 µm, and eradicate established MRSA biofilms at 10× MIC in vitro. More importantly, TD-LP-CA shows enhanced stratum corneum (SC) penetration, reaching more than 500 µm beneath the skin's surface due to modification with the TD peptide, and demonstrates excellent subcutaneous tumor penetration after skin application in vivo. TD-LP-CA displays an excellent therapeutic effect against intradermal MRSA infection in mice after topical dermal administration, as well as a moderate inhibitory effect on subcutaneous melanoma with a 75% tumor inhibition rate. The liposomes prepared herein can be a promising carrier for transcutaneous CA transfer for the treatment of superficial diseases such as skin tumors and infections due to their ability to overcome the skin barrier.

Discovery and Potential Utility of a Novel Non-Invasive Ocular Delivery Platform

To this day, the use of oily eye drops and non-invasive retinal delivery remain a major challenge. Oily eye drops usually cause ocular irritation and interfere with the normal functioning of the eye, while ocular injections for retinal drug delivery cause significant adverse effects and a high burden on the healthcare system. Here, the authors report a novel topical non-invasive ocular delivery platform (NIODP) through the periorbital skin for high-efficiency anterior and posterior ocular delivery in a non-human primate model (NHP). A single dose of about 7 mg JV-MD2 (omega 3 DHA) was delivered via the NIODP and reached the retina at a Cmax of 111 µg/g and the cornea at a Cmax of 66 µg/g. The NIODP also delivered JV-DE1, an anti-inflammatory agent in development for dry eye diseases, as efficiently as eye drops did to the anterior segments of the NHP. The topical NIODP seems to transport drug candidates through the corneal pathway to the anterior and via the conjunctiva/sclera pathway to the posterior segments of the eye. The novel NIODP method has the potential to reshape the landscape of ocular drug delivery. This is especially the case for oily eye drops and retinal delivery, where the success of the treatment lies in the ocular tolerability and bioavailability of drugs in the target tissue.

The Therapeutic Potential of Novel Carnosine Formulations: Perspectives for Drug Development

Carnosine (beta-alanyl-L-histidine) is an endogenous dipeptide synthesized via the activity of the ATP-dependent enzyme carnosine synthetase 1 and can be found at a very high concentration in tissues with a high metabolic rate, including muscles (up to 20 mM) and brain (up to 5 mM). Because of its well-demonstrated multimodal pharmacodynamic profile, which includes anti-aggregant, antioxidant, and anti-inflammatory activities, as well as its ability to modulate the energy metabolism status in immune cells, this dipeptide has been investigated in numerous experimental models of diseases, including Alzheimer's disease, and at a clinical level. The main limit for the therapeutic use of carnosine is related to its rapid hydrolysis exerted by carnosinases, especially at the plasma level, reason why the development of new strategies, including the chemical modification of carnosine or its vehiculation into innovative drug delivery systems (DDS), aiming at increasing its bioavailability and/or at facilitating the site-specific transport to different tissues, is of utmost importance. In the present review, after a description of carnosine structure, biological activities, administration routes, and metabolism, we focused on different DDS, including vesicular systems and metallic nanoparticles, as well as on possible chemical derivatization strategies related to carnosine. In particular, a basic description of the DDS employed or the derivatization/conjugation applied to obtain carnosine formulations, followed by the possible mechanism of action, is given. To the best of our knowledge, this is the first review that includes all the new formulations of carnosine (DDS and derivatives), allowing a decrease or complete prevention of the hydrolysis of this dipeptide exerted by carnosinases, the simultaneous blood-brain barrier crossing, the maintenance or enhancement of carnosine biological activity, and the site-specific transport to different tissues, which then offers perspectives for the development of new drugs.

Small interfering RNA-based nanotherapeutics for treating skin-related diseases

INTRODUCTION

RNA interference (RNAi) has demonstrated great potential in treating skin-related diseases, as small interfering RNA (siRNA) can efficiently silence specific genes. The design of skin delivery systems for siRNA is important to protect the nucleic acid while facilitating both skin targeting and cellular ingestion. Entrapment of siRNA into nanocarriers can accomplish these aims, contributing to improved targeting, controlled release, and increased transfection.

AREAS COVERED

The siRNA-based nanotherapeutics for treating skin disorders are summarized. First, the mechanisms of RNAi are presented, followed by the introduction of challenges for skin therapy. Then, the different nanoparticle types used for siRNA skin delivery are described. Subsequently, we introduce the mechanisms of how nanoparticles enhance siRNA skin penetration. Finally, the current investigations associated with nanoparticulate siRNA application in skin disease management are reviewed.

EXPERT OPINION

The potential application of nanotherapeutic RNAi allows for a novel skin application strategy. Further clinical studies are required to confirm the findings in the cell-based or animal experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for translation to commercialization. siRNA delivery by nanocarriers should be optimized to attain cutaneous targeting without the risk of toxicity.

Neutral Oil-Incorporated Liposomal Nanocarrier for Increased Skin Delivery of Ascorbic Acid

In this study, a neutral oil-incorporated liposomal system (lipo-oil-some, LOS) was designed to improve the skin absorption of ascorbic acid (Vit C), and the effects of an edge activator and neutral oil on the skin absorption of Vit C were evaluated. As components of the LOS system, sodium deoxycholate, polysorbate 80, and cholesterol were screened as edge activators, and camellia oil, tricaprylin, and grapeseed oil were employed as neutral oils. The LOS systems prepared by the ethanol injection method were spherical in shape, 130-350 nm in size, and had 4-27% Vit C loading efficiency (%). In a skin absorption study using a Franz diffusion cell mounted with porcine skin, the LOS system prepared with sodium deoxycholate (10 w/w% of phospholipid) exhibited 1.2-and 2.9-fold higher absorption than those prepared with polysorbate 80 and cholesterol, respectively. Moreover, the type of neutral oil had a marked effect on the absorption of Vit C; the liposomal system containing camellia oil provided 1.3 to 1.8 times higher flux (45.4 μg/cm²∙h) than vesicles with tricaprylin or grapeseed oil, respectively. The optimized lipid nanocarrier is expected to be a promising tool for promoting the skin absorption of Vit C and improving its dermatological functions.

Skin drug delivery using lipid vesicles: A starting guideline for their development

Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.

Liposomes: The Brave Old World

Liposomes have been known of for about 60 years, since they were discovered by A [...].

Co-Encapsulation of Drugs for Topical Application-A Review

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.

Ex Vivo Evaluation of Ethosomes and Transethosomes Applied on Human Skin: A Comparative Study

In this study, the transdermal fate of vesicular nanosystems was investigated. Particularly, ethosomes based on phosphatidylcholine 0.9% w/w and transethosomes based on phosphatidylcholine 0.9 or 2.7% w/w plus polysorbate 80 0.3% w/w as an edge activator were prepared and characterized. The vesicle mean size, morphology and deformability were influenced by both phosphatidylcholine and polysorbate 80. Indeed, the mean diameters of ethosome were around 200 nm, while transethosome's mean diameters were 146 or 350 nm in the case of phosphatidylcholine 0.9 or 2.7%, w/w, respectively. The highest deformability was achieved by transethosomes based on phosphatidylcholine 0.9%, w/w. The three types of vesicular nanosystems were applied on explanted human skin maintained in a bioreactor. Transmission electron microscopy demonstrated that all vesicles were able to enter the skin, keeping their structural integrity. Notably, the vesicle penetration capability was influenced by their physical-chemical features. Indeed, ethosomes reached keratinocytes and even the dermis, phosphatidylcholine 0.9% transethosomes were found in keratinocytes and phosphatidylcholine 2.7% transethosomes were found only in corneocytes of the outer layer. These findings open interesting perspectives for a differentiated application of these vesicles for transdermal drug delivery as a function of the cutaneous pathology to be addressed.

Basal Cell Carcinoma: Pathology, Current Clinical Treatment, and Potential Use of Lipid Nanoparticles

Skin cancer is the most common type of carcinoma diagnosed worldwide, with significant morbidity and mortality rates among Caucasians, in particular basal cell carcinoma (BCC). The main risk factors of BCC are well-identified, and there are many chemotherapeutic drugs available for its treatment. The effectiveness of therapeutic options is governed by several factors, including the location of the tumor, its size, and the presence of metastases (although rare for BCC). However, available treatments are based on non-targeted approaches, which encounter a significant risk of systemic toxicity in several organs. Site-specific chemotherapy for BCC has been proposed via the loading of anticancer drugs into nanoparticles. Among various types of nanoparticles, in this review, we focus on potential new regimens for the treatment of BCC using classical anticancer drugs loaded into novel lipid nanoparticles. To meet patient aesthetic expectations and enhance the effectiveness of basal cell carcinoma treatment, new therapeutic topical strategies are discussed, despite a limited number of reports available in the literature.

Liposomes: structure, composition, types, and clinical applications

Liposomes are now considered the most commonly used nanocarriers for various potentially active hydrophobic and hydrophilic molecules due to their high biocompatibility, biodegradability, and low immunogenicity. Liposomes also proved to enhance drug solubility and controlled distribution, as well as their capacity for surface modifications for targeted, prolonged, and sustained release. Based on the composition, liposomes can be considered to have evolved from conventional, long-circulating, targeted, and immune-liposomes to stimuli-responsive and actively targeted liposomes. Many liposomal-based drug delivery systems are currently clinically approved to treat several diseases, such as cancer, fungal and viral infections; more liposomes have reached advanced phases in clinical trials. This review describes liposomes structure, composition, preparation methods, and clinical applications.

Exploration of Lipid-Based Nanocarriers as Drug Delivery Systems in Diabetic Foot Ulcer

Diabetes mellitus is a chronic manifestation characterized by high levels of glucose in the blood resulting in several complications including diabetic wounds and ulcers, which predominantly require a longer duration of treatment and adversely affect the quality of life of the patients. Nanotechnology-based therapeutics (both intrinsic and extrinsic types) have emerged as a promising treatment in diabetic foot ulcer/chronic wounds owing to their unique characteristics and specific functional properties. In this review, we have focused on the significance of the use of lipids in the healing of diabetic ulcers, their interaction with the injured skin, and recent trends in lipid-based nanocarriers for the healing of diabetic wounds. Lipid nanocarriers are also being investigated for gene therapy in diabetic wound healing to encapsulate nucleic acids such as siRNA and miRNA, which could silence the expression of inflammatory cytokines overexpressed in chronic wounds. Additionally, these are also being explored for encapsulating proteins, peptides, growth factors, and other biological genetic material as therapeutic agents. Lipid-based nanocarriers encompassing a wide variety of carriers such as liposomes, niosomes, ethosomes, solid lipid nanoparticles, and lipidoid nanoparticles that are explored for the treatment of foot ulcers supplemented with relevant research studies have been discussed in the present review. Lipid-based nanodrug delivery systems have demonstrated promising wound healing potential, particularly in diabetic conditions due to the enhanced efficacy of the entrapped active molecules.

Mechanisms of Penetration Enhancement and Transport Utilizing Skin Keratine Liposomes for the Topical Delivery of Licochalcone A

Keratin liposomes have emerged as a useful topical drug delivery system given theirenhanced ability to penetrate the skin, making them ideal as topical drug vehicles. However, the mechanisms of the drug penetration enhancement of keratin liposomes have not been clearly elucidated. Therefore, licochalcone A(LA)-loaded skin keratin liposomes (LALs) were prepared to investigate their mechanisms of penetration enhancement on the skin and inB16F10 cells. Skin deposition studies, differential scanning calorimetry (DSC), attenuated total reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and skin distribution and intracellular distribution studies were carried out to demonstrate the drug enhancement mechanisms of LALs. We found that the optimal application of LALs enhanced drug permeation via alterations in the components, structure, and thermodynamic properties of the stratum corneum (SC), that is, by enhancing the lipid fluidization, altering the skin keratin, and changing the thermodynamic properties of the SC. Moreover, hair follicles were the main penetration pathways for the LA delivery, which occurred in a time-dependent manner. In the B16F10 cells, the skin keratin liposomes effectively delivered LA into the cytoplasm without cytotoxicity. Thus, LAL nanoparticles are promising topical drug delivery systems for pharmaceutical and cosmetic applications.

Lipid Nanocarriers for Hyperproliferative Skin Diseases

Simple Summary

Different drugs, including antiproliferative and corticosteroids in general, are recommended for the treatment of hyperproliferative skin diseases (HSD). The effectiveness of many of these drugs is limited due to their low solubility in water and low penetration in the skin. The loading of these drugs in lipid nanocarriers, such as lipid nanoparticles and liposomes, has been considered as a successful solution to improve the drug bioavailability through the skin, to control their release kinetics and thus reduce the risk of potential side effects. In this work, we discuss the use of lipid nanocarriers loading drugs against HSD.

Abstract

Hyperproliferative skin diseases (HSD) are a group of diseases that include cancers, pre-cancerous lesions and diseases of unknown etiology that present different skin manifestations in terms of the degree and distribution of the injuries. Anti-proliferative agents used to treat these diseases are so diverse, including 5-aminolevulinic acid, 5-fluorouracil, imiquimod, methotrexate, paclitaxel, podophyllotoxin, realgar, and corticosteroids in general. These drugs usually have low aqueous solubility, which consequently decreases skin permeation. Thus, their incorporation in lipid nanocarriers has been proposed with the main objective to increase the effectiveness of topical treatment and reduce side effects. This manuscript aims to describe the advantages of using lipid nanoparticles and liposomes that can be used to load diversity of chemically different drugs for the treatment of HSD.