Imiquimod-oleic acid prodrug-loaded cream reduced drug crystallinity and induced indistinguishable cytotoxicity and apoptosis in mice melanoma tumour

Recent progress in topical and transdermal approaches for melanoma treatment

The global incidence of melanoma, the most lethal form of skin cancer, continues to escalate, emphasizing the urgent need for more effective therapeutic strategies. This review assesses the latest advancements in topical and transdermal drug delivery systems, positioning them as promising alternatives. These systems allow for the direct application of therapeutic agents to tumor sites, enhancing drug effectiveness, improving patient compliance, and reducing systemic toxicity. Specifically, innovations such as nanoparticles, microneedles, and vesicular systems are explored for their potential to optimize topical and localized drug delivery. By incorporating a graphical overview of these drug delivery vehicles, we visually underscore their roles in enhancing therapeutic outcomes across various treatment categories such as chemotherapy, immunotherapy, phototherapy, phytotherapy, and targeted therapy. This article critically evaluates recent breakthroughs, addresses the current challenges faced by researchers, and explores the future directions of topical and transdermal approaches in melanoma management. By presenting a summary of the latest research and predicting future trends, this review aims to inform ongoing developments and encourage further innovation in strategies for treating melanoma.

Evaluation of a Norcantharidin Nanoemulsion Efficacy for Treating B16F1-Induced Melanoma in a Syngeneic Murine Model

Melanoma, a lethal type of cancer originating from melanocytes, is the leading cause of death among skin cancers. While surgical excision of the lesions is the primary treatment for melanoma, not all cases are candidates for surgical procedures. New treatments and complementary options are necessary, given the increasing diagnosis rate. In the present study, a norcantharidin-containing nanoemulsion was developed and evaluated in vivo using a syngeneic graft murine model. Norcantharidin is the demethylated analog of cantharidin, known for its anticancer properties. Our model contemplates surgical excision surgery simulating the standard treatment and the role of the nanoemulsion as a potential adjuvant therapy. We observed a significant decrease in the growth rate of the melanoma lesion in the treated groups compared to the control group, both at the 20th and 30th days of treatment. Moreover, we evaluated the drug bioavailability in serum samples, and the results showed that norcantharidin was detectable in a range of 0.1 to 0.18 mg/mL in the treated groups. Furthermore, histopathological analysis was performed on the amputated tumors, where significant differences were found regarding size, mitosis rate, lymphocytic infiltration, and multispectral quantitative image analysis compared to the control group. If more clinical studies are conducted, the norcantharidin-containing nanoemulsion could be a potential alternative or adjuvant therapy. Topical nanosystems can become or complement standard therapies, which is needed as melanoma affects not only in terms of mortality but also the patient's morbidity and life quality.

Ionic Liquid-Enabled Topical Delivery of Immunomodulators

Skin is one of the most immunologically active organs of the body due to the presence of diverse immune cells and its active involvement in the innate and adaptive immunity. Because of its unique location and immunological role, skin offers an excellent site for the introduction of immunomodulators to synergize with the active immune microenviroment for the desired outcome. However, delivery of immunomodulators to the skin remains a significant challenge due to the skin's barrier properties. Here, we report an ionic liquid (IL)-based strategy to formulate and deliver immunomodulators to the skin. Using imiquimod (IMQ) and triamcinolone acetonide (TCA) as the respective model immunoactive and immunosuppressive drugs, we demonstrated that ILs significantly enhanced the solubility of immunomodulators. In addition, ILs enabled the formulation of the immunomodulators into stable, topically applicable forms. Our ex vivo skin penetration studies revealed that the IL formulations outperformed respective commercial topical comparators and delivered significantly more immunomodulators to deep skin layers. The lead IMQ formulation exhibited >10-fold better efficacy in delivering IMQ to the deep skin layers as compared to the commercial 5% IMQ cream. Lead TCA formulations achieved a dose level in deep skin layers that is comparable to that by clinically used intralesional injections. Our data collectively suggest that the IL-based strategy can be a simple and effective platform for delivery of immunomodulators to the skin.

Skin Penetration Enhancement Strategies Used in the Development of Melanoma Topical Treatments

Malignant melanoma is an aggressive form of skin cancer for which there is currently no reliable therapy and is considered one of the leading health issues in the USA. At present, surgery is the most effective and acceptable treatment; however, surgical excision can be impractical in certain circumstances. Topical skin delivery of drugs using topical formulations is a potential alternative approach which can have many advantages aside from being a non-invasive delivery route. Nevertheless, the presence of the stratum corneum (SC) limits the penetration of drugs through the skin, lowering their treatment efficacy and raising concerns among physicians and patients as to their effectiveness. Currently, research groups are trying to circumvent the SC barrier by using skin penetration enhancement (SPE) strategies. The SPE strategies investigated include chemical skin penetration enhancers (CPEs), physical skin penetration enhancers (PPEs), nanocarrier systems, and a combination of SPE strategies (cream). Of these, PPEs and cream are the most advanced approaches in terms of preclinical and clinical studies, respectively.

Antimicrobial Peptide Designing and Optimization Employing Large-Scale Flexibility Analysis of Protein-Peptide Fragments

The mankind relies on the use of antibiotics for a healthy life. The epidemic-like emergence of drug-resistant bacterial strains is increasingly becoming one of the leading causes of morbidity and mortality, which gives rise to design a potential antimicrobial peptide (AMP). Here, we have designed the potential AMP using the extensive dynamics simulation since protein-peptide interactions are linked to large conformational changes. Therefore, we have employed the advanced computational avenue CABS molecular docking method that enabled the flexible peptide-protein molecular docking with a large-scale rearrangement of the protein. Lead AMP was investigated against the wild-type (WT) and mutant-PBP5 (MT-PBP5) proteins (antiresistance property). AMP20 showed strong interactions with wtPBP5 and mtPBP5 and involvement of a large number of elements in interactions determined through an atomic model study. Full flexibility analysis showed the stable interaction of AMP20 with both the wild-type and mutant form of PBP5 with root-mean-square deviation (RMSD) values of ∼4.51 and 4.85 Å, respectively. Moreover, peptide dynamics showed involvement of all residues of AMP20 through contact map analysis, and extensive simulation confirmed the stable interaction of AMP20, with lower values of RMSD, radius of gyration, and root-mean-square fluctuation. This study paves the way for a potential approach to design the AMP with amino acid walking and large-scale conformational rearrangements of amino acids.