Microneedle-Based Delivery of Amphotericin B for Treatment of Cutaneous Leishmaniasis

Efficacy of Diterpene Polyalthic Acid Combined with Amphotericin B against Leishmania amazonensis In Vitro

Background/Objectives: Leishmaniasis, a neglected disease caused by Leishmania spp. including L. amazonensis, urgently requires new treatments. Polyalthic acid (PA), a natural diterpene from Copaifera spp., has previously demonstrated significant antiparasitic potential. This study evaluated the leishmanicidal effects of polyalthic acid (PA), alone and with amphotericin B (AmpB), on L. amazonensis promastigote and amastigote forms. Results: PA showed significant activity against promastigotes, with 50% effective concentration (EC50) values of 2.01 μM at 24 h and an EC50 of 3.22 μM against amastigotes after 48 h. The PA and AmpB combination exhibited a synergistic effect on both forms without inducing cytotoxicity or hemolysis. Morphological changes in promastigotes, including vacuole formation and cell rounding, were more pronounced with the combination. Conclusions: These findings suggest that PA and AmpB together could form a promising new treatment strategy against Leishmania infections, offering enhanced efficacy without added toxicity.

Microneedles-Based Theranostic Platform: From the Past to the Future

Fully integrated theranostic devices are highly esteemed in clinical applications, offering immense potential in real-time disease monitoring and personalized care. Microneedles (MNs), as innovative and wearable devices, boast important advantages in biosensing and therapy, thus holding significant promise in the advancement of diagnostic and therapeutic platforms. Encouragingly, advancements in electrochemical sensing technology, micronano fabrication, and biocompatible materials are propelling momentum for MNs-based closed-loop systems, enhancing detection capabilities, biocompatibility, and cost-effectiveness. Moreover, the notable progress in integrating MN chips with other biochips signifies a frontier for growth. Successful clinical trials in target molecule monitoring and drug delivery domains herald excellent clinical translational prospects for the aforementioned theranostic platform. Finally, we delineate both challenges and opportunities in the development of integrated diagnostic and therapeutic MN systems, including continuous monitoring, intelligent control algorithms, safety, and regulatory considerations.

In Vivo Evaluation of Sepigel-Based Meglumine Antimoniate and Amphotericin B for Cutaneous Leishmaniasis Treatment

Cutaneous leishmaniasis (CL) poses a significant public health concern in endemic regions due to its increasing prevalence and substantial impact on affected individuals. This disease is primarily caused by the Leishmania protozoa, which are transmitted through insect bites, and it manifests as a range of symptoms, from self-healing lesions to severe disfigurement. Current treatments, which often involve the parenteral administration of antimonials, face challenges such as poor compliance and adverse effects. This study investigates the efficacy of topical formulations containing meglumine antimoniate (MA) and amphotericin B (AmB), using Sepigel as an excipient, for treating CL. In the in vivo study, BALB/c mice infected with L. amazonensis developed lesions at the injection site five weeks post-infection. Subsequently, the mice were divided into eight groups: untreated mice, mice treated orally with miltefosine, mice treated intraperitoneally with MA, and mice treated topically with 15%, 22.5%, and 30% MA-Sepigel, as well as those treated with AmB-Sepigel. Treatments were applied daily for two weeks, and the results revealed a significant reduction in lesion size and parasite burden following topical application, particularly with the AmB-Sepigel formulations and 30% MA-Sepigel. Additionally, Sepigel-based treatments demonstrated improved patient compliance and reduced toxicity compared to systemic therapies. These findings underscore the potential of Sepigel-based formulations as a promising alternative for CL treatment. They offer enhanced efficacy and tolerability, while reducing the systemic toxicity associated with conventional therapies.

Local amphotericin B therapy for Cutaneous Leishmaniasis: A systematic review

BACKGROUND

Cutaneous leishmaniasis (CL) is characterized by potentially disfiguring skin ulcers carrying significant social stigma. To mitigate systemic drug exposure and reduce the toxicity from available treatments, studies addressing new local therapeutic strategies using available medications are coming up. This review systematically compiles preclinical and clinical data on the efficacy of amphotericin B (AmB) administered locally for cutaneous leishmaniasis.

METHODOLOGY

Structured searches were conducted in major databases. Clinical studies reporting cure rates and preclinical studies presenting any efficacy outcome were included. Exclusion criteria comprised nonoriginal studies, in vitro investigations, studies with fewer than 10 treated patients, and those evaluating AmB in combination with other antileishmanial drug components.

PRINCIPAL FINDINGS

A total of 21 studies were identified, encompassing 16 preclinical and five clinical studies. Preclinical assessments generally involved the topical use of commercial AmB formulations, often in conjunction with carriers or controlled release systems. However, the variation in the treatment schedules hindered direct comparisons. In clinical studies, topical AmB achieved a pooled cure rate of 45.6% [CI: 27.5-64.8%; I2 = 79.7; p = 0.002), while intralesional (IL) administration resulted in a 69.8% cure rate [CI: 52.3-82.9%; I2 = 63.9; p = 0.06). In the direct comparison available, no significant difference was noted between AmB-IL and meglumine antimoniate-IL administration (OR:1.7; CI:0.34-9.15, I2 = 79.1; p = 0.00), however a very low certainty of evidence was verified.

CONCLUSIONS

Different AmB formulations and administration routes have been explored in preclinical and clinical studies. Developing therapeutic technologies is evident. Current findings might be interpreted as a favorable proof of concept for the local AmB administration which makes this intervention eligible to be explored in future well-designed studies towards less toxic treatments for leishmaniasis.

Current Status of Microneedle Array Technology for Therapeutic Delivery: From Bench to Clinic

In recent years, microneedle (MN) patches have emerged as an alternative technology for transdermal delivery of various drugs, therapeutics proteins, and vaccines. Therefore, there is an urgent need to understand the status of MN-based therapeutics. The article aims to illustrate the current status of microneedle array technology for therapeutic delivery through a comprehensive review. However, the PubMed search was performed to understand the MN's therapeutics delivery status. At the same time, the search shows the number no of publications on MN is increasing (63). The search was performed with the keywords "Coated microneedle," "Hollow microneedle," "Dissolvable microneedle," and "Hydrogel microneedle," which also shows increasing trend. Similarly, the article highlighted the application of different microneedle arrays for treating different diseases. The article also illustrated the current status of different phases of MN-based therapeutics clinical trials. It discusses the delivery of different therapeutic molecules, such as drug molecule delivery, using microneedle array technology. The approach mainly discusses the delivery of different therapeutic molecules. The leading pharmaceutical companies that produce the microneedle array for therapeutic purposes have also been discussed. Finally, we discussed the limitations and future prospects of this technology.

Going below and beyond the surface: Microneedle structure, materials, drugs, fabrication, and applications for wound healing and tissue regeneration

Microneedle, as a novel drug delivery system, has attracted widespread attention due to its non-invasiveness, painless and simple administration, controllable drug delivery, and diverse cargo loading capacity. Although microneedles are initially designed to penetrate stratum corneum of skin for transdermal drug delivery, they, recently, have been used to promote wound healing and regeneration of diverse tissues and organs and the results are promising. Despite there are reviews about microneedles, few of them focus on wound healing and tissue regeneration. Here, we review the recent advances of microneedles in this field. We first give an overview of microneedle system in terms of its potential cargos (e.g., small molecules, macromolecules, nucleic acids, nanoparticles, extracellular vesicle, cells), structural designs (e.g., multidrug structures, adhesive structures), material selection, and drug release mechanisms. Then we briefly summarize different microneedle fabrication methods, including their advantages and limitations. We finally summarize the recent progress of microneedle-assisted wound healing and tissue regeneration (e.g., skin, cardiac, bone, tendon, ocular, vascular, oral, hair, spinal cord, and uterine tissues). We expect that our article would serve as a guideline for readers to design their microneedle systems according to different applications, including material selection, drug selection, and structure design, for achieving better healing and regeneration efficacy.

Transdermal delivery via medical device technologies

INTRODUCTION

Despite their effectiveness and indispensability, many drugs are poorly solvated in aqueous solutions. Over recent decades, the need for targeted drug delivery has led to the development of pharmaceutical formulations with enhanced lipid solubility to improve their delivery properties. Therefore, a dependable approach for administering lipid-soluble drugs needs to be developed.

AREAS COVERED

The advent of 3D printing or additive manufacturing (AM) has revolutionized the development of medical devices, which can effectively enable the delivery of lipophilic drugs to the targeted tissues. This review focuses on the use of microneedles and iontophoresis for transdermal drug delivery. Microneedle arrays, inkjet printing, and fused deposition modeling have emerged as valuable approaches for delivering several classes of drugs. In addition, iontophoresis has been successfully employed for the effective delivery of macromolecular drugs.

EXPERT OPINION

Microneedle arrays, inkjet printing, and fused deposition are potentially useful for many drug delivery applications; however, the clinical and commercial adoption rates of these technologies are relatively low. Additional efforts is needed to enable the pharmaceutical community to fully realize the benefits of these technologies.

Micromolding of Amphotericin-B-Loaded Methoxyethylene-Maleic Anhydride Copolymer Microneedles

Biocompatible and biodegradable materials have been used for fabricating polymeric microneedles to deliver therapeutic drug molecules through the skin. Microneedles have advantages over other drug delivery methods, such as low manufacturing cost, controlled drug release, and the reduction or absence of pain. The study examined the delivery of amphotericin B, an antifungal agent, using microneedles that were fabricated using a micromolding technique. The microneedle matrix was made from Gantrez^TM AN-119 BF, a benzene-free methyl vinyl ether/maleic anhydride copolymer. The Gantrez^TM AN-119 BF was mixed with water; after water evaporation, the polymer exhibited sufficient strength for microneedle fabrication. Molds cured at room temperature remained sharp and straight. SEM images showed straight and sharp needle tips; a confocal microscope was used to determine the height and tip diameter for the microneedles. Nanoindentation was used to obtain the hardness and Young’s modulus values of the polymer. Load–displacement testing was used to assess the failure force of the needles under compressive loading. These two mechanical tests confirmed the mechanical properties of the needles. In vitro studies validated the presence of amphotericin B in the needles and the antifungal properties of the needles. Amphotericin B Gantrez^TM microneedles fabricated in this study showed appropriate characteristics for clinical translation in terms of mechanical properties, sharpness, and antifungal properties.

An appraisal of the scientific current situation and new perspectives in the treatment of cutaneous leishmaniasis

Leishmaniasis is a Neglected Tropical Diseases caused by protozoan parasites of the genus Leishmania. It is a major health problem in many tropical and subtropical regions of the world and can produce three different clinical manifestations, among which cutaneous leishmaniasis has a higher incidence in the world than the other clinical forms. There are no recognized and reliable means of chemoprophylaxis or vaccination against infections with different forms of leishmaniasis. In addition, chemotherapy, unfortunately, remains, in many respects, unsatisfactory. Therefore, there is a continuing and urgent need for new therapies against leishmaniasis that are safe and effective in inducing a long-term cure. This review summarizes the latest advances in currently available treatments and improvements in the development of drug administration. In addition, an analysis of the in vivo assays was performed and the challenges facing promising strategies to treat CL are discussed. The treatment of leishmaniasis will most likely evolve into an approach that uses multiple therapies simultaneously to reduce the possibility of developing drug resistance. There is a continuous effort to discover new drugs to improve the treatment of leishmaniasis, but this is mainly at the level of individual researchers. Undoubtedly, more funding is needed in this area, as well as greater participation of the pharmaceutical industry to focus efforts on the development of chemotherapeutic agents and vaccines for this and other neglected tropical diseases.

Nanotechnology approaches for delivery and targeting of Amphotericin B in fungal and parasitic diseases

Amphotericin B (AMB), with widespread antifungal and anti-parasitic activities and low cross-resistance with other drugs, has long been identified as a potent antimicrobial drug. However, its clinical toxicities, especially nephrotoxicity, have limited its use in clinical practice. Lately, nano-based systems have been the subject of serious research and becoming an effective strategy to improve toxicity and antimicrobial potency. Commercial AMB lipid formulations have been developed in order to improve the therapeutic index and nephrotoxicity, while limited use is mainly due to their high cost. The review aimed to highlight the updated information on nanotechnology-based approaches to the development of AMB delivery and targeting systems for treatment of fungal diseases and leishmaniasis, regarding therapeutic challenges and achievements of various delivery systems.

Cytotoxic polyhydroxy sterols from the Egyptian Red Sea soft coral Sarcophyton acutum

The methanolic extract and its sub-extracts (viz, n-hexane, DCM, EtOAc and MeOH) of the soft coral Sarcophyton acutum were evaluated as anti-Leishmania major and as anticancer (against the HepG2, MCF-7, and A549 cell lines) using the MTT assay. Six polyhydroxy sterols (1-6) were isolated from the most active cytotoxic and anti-leishmanial EtOAc-soluble fraction. Their structures were established as two new polyhydroxy sterols, acutumosterols A (1) and B (2), and four known structural analogues (3-6) by intensive spectroscopic analyses, and by comparison with data of related compounds. Compound 4 exerted noticeable cytotoxicity against HepG2 cell line (IC₅₀ 17.2 ± 1.5 μg/mL), while the other pure isolates showed weak to moderate cytotoxicity (24.8 ± 2.8-57.2 ± 5.2). The results were discussed in relation to the structural features of these closely related sterols.

Exploring membrane proteins of Leishmania major to design a new multi-epitope vaccine using immunoinformatics approach

Leishmaniasis is one of the major global endemic diseases. Among all the different forms of the disease, cutaneous Leishmaniasis has the highest prevalence worldwide. Treatment with current drugs has not had a significant effect on the improvement of the disease. An attempt to replace an appropriate vaccine that can stimulate host cellular immunity and induce the response of Major histocompatibility complex I (MHCI) and Major histocompatibility complex II (MHCII) against Leishmania is essential. Vaccine production remains a challenge despite the use of different antigens for vaccination against Leishmania major. Hence, we were used the immunoinformatics approach to design a new multi-epitope vaccine against L. major using immunogenic outer membrane proteins. Helper T-lymphocyte (HTL) and Cytotoxic T lymphocyte (CTL) epitopes were predicted and for final confirmation of the selected epitopes, docking analysis, and molecular dynamics simulation was performed. Then, GDGDG linker and profilin adjuvant were added to enhance the immunity of vaccines. The designed vaccine was evaluated in terms of molecular weight, PI, immunogenicity, and allergenicity. Moreover, the secondary and three-dimensional structure of the final construct was identified. In silico cloning approach was carried out to improve expression of the vaccine construct. Finally, molecular docking, followed by molecular dynamic was performed to determine the interaction between multi-epitope vaccine and TLR11. We hope that the designed vaccine can be a good candidate for the development of cutaneous leishmaniasis vaccine. but its effectiveness should be assessed in vivo.

Advances in Antimicrobial Microneedle Patches for Combating Infections

Skin infections caused by bacteria, viruses and fungi are difficult to treat by conventional topical administration because of poor drug penetration across the stratum corneum. This results in low bioavailability of drugs to the infection site, as well as the lack of prolonged release. Emerging antimicrobial transdermal and ocular microneedle patches have become promising medical devices for the delivery of various antibacterial, antifungal, and antiviral therapeutics. In the present review, skin anatomy and its barriers along with skin infection are discussed. Potential strategies for designing antimicrobial microneedles and their targeted therapy are outlined. Finally, biosensing microneedle patches associated with personalized drug therapy and selective toxicity toward specific microbial species are discussed.

Topical Amphotericin B Semisolid Dosage Form for Cutaneous Leishmaniasis: Physicochemical Characterization, Ex Vivo Skin Permeation and Biological Activity

Amphotericin B (AmB) is a potent antifungal successfully used intravenously to treat visceral leishmaniasis but depending on the Leishmania infecting species, it is not always recommended against cutaneous leishmaniasis (CL). To address the need for alternative topical treatments of CL, the aim of this study was to elaborate and characterize an AmB gel. The physicochemical properties, stability, rheology and in vivo tolerance were assayed. Release and permeation studies were performed on nylon membranes and human skin, respectively. Toxicity was evaluated in macrophage and keratinocyte cell lines, and the activity against promastigotes and intracellular amastigotes of Leishmania infantum was studied. The AmB gel remained stable for a period of two months, with optimal properties for topical use and no apparent toxic effect on the cell lines. High amounts of AmB were found in damaged and non-damaged skin (1230.10 ± 331.52 and 2484.57 ± 439.12 µg/g/cm², respectively) and they were above the IC₅₀ of AmB for amastigotes. Although there were no differences in the in vitro anti-leishmanial activity between the AmB solution and gel, the formulation resulted in a higher amount of AmB being retained in the skin, and is therefore a candidate for further studies of in vivo efficacy.