Drug delivery nanoparticles in skin cancers

Review of Advances in Coating and Functionalization of Gold Nanoparticles: From Theory to Biomedical Application

Nanoparticles, especially gold nanoparticles (Au NPs) have gained increasing interest in biomedical applications. Used for disease prevention, diagnosis and therapies, its significant advantages in therapeutic efficacy and safety have been the main target of interest. Its application in immune system prevention, stability in physiological environments and cell membranes, low toxicity and optimal bioperformances are critical to the success of engineered nanomaterials. Its unique optical properties are great attractors. Recently, several physical and chemical methods for coating these NPs have been widely used. Biomolecules such as DNA, RNA, peptides, antibodies, proteins, carbohydrates and biopolymers, among others, have been widely used in coatings of Au NPs for various biomedical applications, thus increasing their biocompatibility while maintaining their biological functions. This review mainly presents a general and representative view of the different types of coatings and Au NP functionalization using various biomolecules, strategies and functionalization mechanisms.

Synthesis and characterization of 4-nitro benzaldehyde with ZnO-based nanoparticles for biomedical applications

Globally, cancer is the leading cause of death and morbidity, and skin cancer is the most common cancer diagnosis. Skin problems can be treated with nanoparticles (NPs), particularly with zinc oxide (ZnO) NPs, which have antioxidant, antibacterial, anti-inflammatory, and anticancer properties. An antibacterial activity of zinc oxide nanoparticles prepared in the presence of 4-nitrobenzaldehyde (4NB) was also tested in the present study. In addition, the influence of synthesized NPs on cell apoptosis, cell viability, mitochondrial membrane potential (MMP), endogenous reactive oxygen species (ROS) production, apoptosis, and cell adhesion was also examined. The synthesized 4-nitro benzaldehyde with ZnO (4NBZnO) NPs were confirmed via characterization techniques. 4NBZnO NPs showed superior antibacterial properties against the pathogens tested in antibacterial investigations. As a result of dose-based treatment with 4NBZnO NPs, cell viability, and MMP activity of melanoma cells (SK-MEL-3) cells were suppressed. A dose-dependent accumulation of ROS was observed in cells exposed to 4NBZnO NPs. As a result of exposure to 4NBZnO NPs in a dose-dependent manner, viable cells declined and apoptotic cells increased. This indicates that apoptotic cell death was higher. The cell adhesion test revealed that 4NBZnO NPs reduced cell adhesion and may promote apoptosis of cancer cells because of enhanced ROS levels.

Nanoformulations for dermal delivery of imiquimod: The race of "soft" against "hard"

Imiquimod (IMQ) is an immunostimulating agent used in the treatment of basal cell carcinoma and actinic keratosis. Due to its low solubility and poor skin bioavailability, the dermal formulation of IMQ remains challenging. In analogy to tyre compounds used in Formula 1 racing, we compare four types of nanosystems belonging to three groups: (i) "hard" nanoparticles in the form of IMQ nanocrystals, (ii) "intermediate" nanoparticles in the form of liposomes and lipid nanocapsules, and (iii) "soft" nanoparticles in the form of a nanoemulsion based on oleic acid. The nanoemulsion and nanocrystals were able to incorporate the highest amount of IMQ (at least 2 wt%) compared to liposomes (0.03 wt%) and lipid nanocapsules (0.08 wt%). Regarding size, liposomes, and lipid nanocapsules were rather small (around 40 nm) whereas nanocrystals and nanoemulsion were larger (around 200 nm). All developed nanoformulations showed high efficiency to deliver IMQ into the skin tissue without undesirable subsequent permeation through the skin to acceptor. Especially, the 2 wt% IMQ nanoemulsion accumulated 129 μg/g IMQ in the skin, compared to 34 μg/g of a 5 wt% commercial cream. The effects of the respective nanoparticulate systems were discussed with respect to their possible diffusion kinetics (Brownian motion vs. settling) in the aqueous phase.

Skin cancer: understanding the journey of transformation from conventional to advanced treatment approaches

Skin cancer is a global threat to the healthcare system and is estimated to incline tremendously in the next 20 years, if not diagnosed at an early stage. Even though it is curable at an early stage, novel drug identification, clinical success, and drug resistance is another major challenge. To bridge the gap and bring effective treatment, it is important to understand the etiology of skin carcinoma, the mechanism of cell proliferation, factors affecting cell growth, and the mechanism of drug resistance. The current article focusses on understanding the structural diversity of skin cancers, treatments available till date including phytocompounds, chemotherapy, radiotherapy, photothermal therapy, surgery, combination therapy, molecular targets associated with cancer growth and metastasis, and special emphasis on nanotechnology-based approaches for downregulating the deleterious disease. A detailed analysis with respect to types of nanoparticles and their scope in overcoming multidrug resistance as well as associated clinical trials has been discussed.

In Vitro Approaches to Explore the Anticancer Potential of One Natural Flavanone and Four Derivatives Loaded in Biopolymeric Nanoparticles for Application in Topical Delivery Treatments

The increasing number of skin cancer cases worldwide and the adverse side effects of current treatments have led to the search for new anticancer agents. In this present work, the anticancer potential of the natural flavanone 1, extracted from Eysenhardtia platycarpa, and four flavanone derivatives 1a-d obtained by different reactions from 1 was investigated by an in silico study and through cytotoxicity assays in melanoma (M21), cervical cancer (HeLa) cell lines and in a non-tumor cell line (HEK-293). The free compounds and compounds loaded in biopolymeric nanoparticles (PLGA NPs 1, 1a-d) were assayed. A structure-activity study (SAR) was performed to establish the main physicochemical characteristics that most contribute to cytotoxicity. Finally, ex vivo permeation studies were performed to assess the suitability of the flavanones for topical administration. Results revealed that most of the studied flavanones and their respective PLGA NPs inhibited cell growth depending on the concentration; 1b should be highlighted. The descriptors of the energetic factor were those that played a more important role in cellular activity. PLGA NPs demonstrated their ability to penetrate (Q_p of 17.84-118.29 µg) and be retained (Q_r of 0.01-1.44 g/g_skin/cm²) in the skin and to exert their action for longer. The results of the study suggest that flavanones could offer many opportunities as a future anticancer topical adjuvant treatment.

Exploring the Versatility of Microemulsions in Cutaneous Drug Delivery: Opportunities and Challenges

Microemulsions are novel drug delivery systems that have garnered significant attention in the pharmaceutical research field. These systems possess several desirable characteristics, such as transparency and thermodynamic stability, which make them suitable for delivering both hydrophilic and hydrophobic drugs. In this comprehensive review, we aim to explore different aspects related to the formulation, characterization, and applications of microemulsions, with a particular emphasis on their potential for cutaneous drug delivery. Microemulsions have shown great promise in overcoming bioavailability concerns and enabling sustained drug delivery. Thus, it is crucial to have a thorough understanding of their formulation and characterization in order to optimize their effectiveness and safety. This review will delve into the different types of microemulsions, their composition, and the factors that affect their stability. Furthermore, the potential of microemulsions as drug delivery systems for skin applications will be discussed. Overall, this review will provide valuable insights into the advantages of microemulsions as drug delivery systems and their potential for improving cutaneous drug delivery.

Functional nano-systems for transdermal drug delivery and skin therapy

Transdermal drug delivery is one of the least intrusive and patient-friendly ways for therapeutic agent administration. Recently, functional nano-systems have been demonstrated as one of the most promising strategies to treat skin diseases by improving drug penetration across the skin barrier and achieving therapeutically effective drug concentrations in the target cutaneous tissues. Here, a brief review of functional nano-systems for promoting transdermal drug delivery is presented. The fundamentals of transdermal delivery, including skin biology and penetration routes, are introduced. The characteristics of functional nano-systems for facilitating transdermal drug delivery are elucidated. Moreover, the fabrication of various types of functional transdermal nano-systems is systematically presented. Multiple techniques for evaluating the transdermal capacities of nano-systems are illustrated. Finally, the advances in the applications of functional transdermal nano-systems for treating different skin diseases are summarized.

Nanoparticles loaded with pharmacologically active plant-derived natural products: Biomedical applications and toxicity

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.

Polymeric Nanoparticles as Tunable Nanocarriers for Targeted Delivery of Drugs to Skin Tissues for Treatment of Topical Skin Diseases

The topical route is the most appropriate route for the targeted delivery of drugs to skin tissues for the treatment of local skin diseases; however, the stratum corneum (SC), the foremost layer of the skin, acts as a major barrier. Numerous passive and active drug delivery techniques have been exploited to overcome this barrier; however, these modalities are associated with several detrimental effects which restrict their clinical applicability. Alternatively, nanotechnology-aided interventions have been extensively investigated for the topical administration of a wide range of therapeutics. In this review, we have mainly focused on the biopharmaceutical significance of polymeric nanoparticles (PNPs) (made from natural polymers) for the treatment of various topical skin diseases such as psoriasis, atopic dermatitis (AD), skin infection, skin cancer, acute-to-chronic wounds, and acne. The encapsulation of drug(s) into the inner core or adsorption onto the shell of PNPs has shown a marked improvement in their physicochemical properties, avoiding premature degradation and controlling the release kinetics, permeation through the SC, and retention in the skin layers. Furthermore, functionalization techniques such as PEGylation, conjugation with targeting ligand, and pH/thermo-responsiveness have shown further success in optimizing the therapeutic efficacy of PNPs for the treatment of skin diseases. Despite enormous progress in the development of PNPs, their clinical translation is still lacking, which could be a potential future perspective for researchers working in this field.

Enhancing Skin Cancer Immunotheranostics and Precision Medicine through Functionalized Nanomodulators and Nanosensors: Recent Development and Prospects

Skin cancers, especially melanomas, present a formidable diagnostic and therapeutic challenge to the scientific community. Currently, the incidence of melanomas shows a high increase worldwide. Traditional therapeutics are limited to stalling or reversing malignant proliferation, increased metastasis, or rapid recurrence. Nonetheless, the advent of immunotherapy has led to a paradigm shift in treating skin cancers. Many state-of-art immunotherapeutic techniques, namely, active vaccination, chimeric antigen receptors, adoptive T-cell transfer, and immune checkpoint blockers, have achieved a considerable increase in survival rates. Despite its promising outcomes, current immunotherapy is still limited in its efficacy. Newer modalities are now being explored, and significant progress is made by integrating cancer immunotherapy with modular nanotechnology platforms to enhance its therapeutic efficacy and diagnostics. Research on targeting skin cancers with nanomaterial-based techniques has been much more recent than other cancers. Current investigations using nanomaterial-mediated targeting of nonmelanoma and melanoma cancers are directed at augmenting drug delivery and immunomodulation of skin cancers to induce a robust anticancer response and minimize toxic effects. Many novel nanomaterial formulations are being discovered, and clinical trials are underway to explore their efficacy in targeting skin cancers through functionalization or drug encapsulation. The focus of this review rivets on theranostic nanomaterials that can modulate immune mechanisms toward protective, therapeutic, or diagnostic approaches for skin cancers. The recent breakthroughs in nanomaterial-based immunotherapeutic modulation of skin cancer types and diagnostic potentials in personalized immunotherapies are discussed.

Synthesis and Anti-Melanoma Activity of L-Cysteine-Coated Iron Oxide Nanoparticles Loaded with Doxorubicin

In this study, we report on the synthesis of L-Cysteine (L-Cys)-coated magnetic iron oxide nanoparticles (NPs) loaded with doxorubicin (Dox). The Fe₃O₄-L-Cys-Dox NPs were extensively characterized for their compositional and morpho-structural features using EDS, SAED, XRD, FTIR and TEM. XPS, Mӧssbauer spectroscopy and SQUID measurements were also performed to determine the electronic and magnetic properties of the Fe₃O₄-L-Cys-Dox nanoparticles. Moreover, by means of a FO-SPR sensor, we evidenced and confirmed the binding of Dox to L-Cys. Biological tests on mouse (B16F10) and human (A375) metastatic melanoma cells evidenced the internalization of magnetic nanoparticles delivering Dox. Half maximum inhibitory concentration IC50 values of Fe₃O₄-L-Cys-Dox were determined for both cell lines: 4.26 µg/mL for A375 and 2.74 µg/mL for B16F10, as compared to 60.74 and 98.75 µg/mL, respectively, for unloaded controls. Incubation of cells with Fe₃O₄-L-Cys-Dox modulated MAPK signaling pathway activity 3 h post-treatment and produced cell cycle arrest and increased apoptosis by 48 h. We show that within the first 2 h of incubation in physiological (pH = 7.4) media, ~10-15 µM Dox/h was released from a 200 µg/mL Fe₃O₄-L-Cys-Dox solution, as compared to double upon incubation in citrate solution (pH = 3), which resembles acidic environment conditions. Our results highlight the potential of Fe₃O₄-L-Cys-Dox NPs as efficient drug delivery vehicles in melanoma therapy.

Progresses in Nano-Enabled Platforms for the Treatment of Vaginal Disorders

BACKGROUND

The most common vaginal disorders are within the uterus. According to the latest statistics, vaginal disorders occur in 50% to 60% of females. Although curative treatments rely on surgical therapy, still first-line treatment is a non invasive drug. Conventional therapies are available in the oral and parenteral route, leading to nonspecific targeting, which can cause dose-related side effects. Vaginal disorders are localized uterine disorders in which intrauterine delivery via the vaginal site is deemed the preferable route to mitigate clinical drug delivery limitations.

OBJECTIVE

This study emphasizes the progress of site-specific and controlled delivery of therapeutics in the treatment of vaginal disorders and systemic adverse effects as well as the therapeutic efficacy.

METHODS

Related research reports and patents associated with topics are collected, utilized, and summarized the key findings.

RESULTS

The comprehensive literature study and patents like (US 9393216 B2), (JP6672370B2), and (WO2018041268A1) indicated that nanocarriers are effective above traditional treatments and have some significant efficacy with novelty.

CONCLUSION

Nowadays, site-specific and controlled delivery of therapeutics for the treatment of vaginal disorders is essential to prevent systemic adverse effects and therapeutic efficacy would be more effective. Nanocarriers have therefore been used to bypass the problems associated with traditional delivery systems for the vaginal disorder.

Skin Cancer Management: Current Scenario And Future Perspectives

Skin cancer is a life-threatening disease and has caused significant loss to human health across the globe. Its prevalence has been increasing every year and is one of the common malignancies in the case of organ transplant recipients, of which 95% constitute basal cell and squamous cell carcinomas. The prime factor causing skin cancer is UV radiation. Around the 20th century, sunlight was the primary cause of skin cancer. A novel hypothesis by US scientists stated that cutaneous melanoma was mainly due to recurrent exposure to the sun, whereas keratinocyte cancer occurred due to progressive accumulation of sun exposure. Management of skin cancer is done via various approaches, including cryotherapy, radiotherapy, and photodynamic therapy. Post-discovery of X-rays, radiotherapy has proven to treat skin cancers to some extent, but the indications are uncertain since it depends upon the type of tumour and surgical treatment required for the patient. Due to various limitations of skin cancer treatment and increased severity, there is a requirement for cost-effective, novel, and efficient treatment. Various nanocarriers such as SLNs, magnetic nanoparticles, gold nanoparticles, carbon nanotubes, etc., are the potential carriers in the management and prognosis of both non-melanoma and melanoma skin cancer. Various research and review databases and patent reports have been studied, and information compiled to extract the results. The review also discusses the role of various nanocarriers in treating and diagnosing skin cancer.

Nanoparticles for Topical Application in the Treatment of Skin Dysfunctions-An Overview of Dermo-Cosmetic and Dermatological Products

Nanomaterials (NM) arouse interest in various fields of science and industry due to their composition-tunable properties and the ease of modification. They appear currently as components of many consumer products such as sunscreen, dressings, sports clothes, surface-cleaning agents, computer devices, paints, as well as pharmaceutical and cosmetics formulations. The use of NPs in products for topical applications improves the permeation/penetration of the bioactive compounds into deeper layers of the skin, providing a depot effect with sustained drug release and specific cellular and subcellular targeting. Nanocarriers provide advances in dermatology and systemic treatments. Examples are a non-invasive method of vaccination, advanced diagnostic techniques, and transdermal drug delivery. The mechanism of action of NPs, efficiency of skin penetration, and potential threat to human health are still open and not fully explained. This review gives a brief outline of the latest nanotechnology achievements in products used in topical applications to prevent and treat skin diseases. We highlighted aspects such as the penetration of NPs through the skin (influence of physical-chemical properties of NPs, the experimental models for skin penetration, methods applied to improve the penetration of NPs through the skin, and methods applied to investigate the skin penetration by NPs). The review summarizes various therapies using NPs to diagnose and treat skin diseases (melanoma, acne, alopecia, vitiligo, psoriasis) and anti-aging and UV-protectant nano-cosmetics.

Recent Trends and Developments in Multifunctional Nanoparticles for Cancer Theranostics

Conventional anticancer treatments, such as radiotherapy and chemotherapy, have significantly improved cancer therapy. Nevertheless, the existing traditional anticancer treatments have been reported to cause serious side effects and resistance to cancer and even to severely affect the quality of life of cancer survivors, which indicates the utmost urgency to develop effective and safe anticancer treatments. As the primary focus of cancer nanotheranostics, nanomaterials with unique surface chemistry and shape have been investigated for integrating cancer diagnostics with treatment techniques, including guiding a prompt diagnosis, precise imaging, treatment with an effective dose, and real-time supervision of therapeutic efficacy. Several theranostic nanosystems have been explored for cancer diagnosis and treatment in the past decade. However, metal-based nanotheranostics continue to be the most common types of nonentities. Consequently, the present review covers the physical characteristics of effective metallic, functionalized, and hybrid nanotheranostic systems. The scope of coverage also includes the clinical advantages and limitations of cancer nanotheranostics. In light of these viewpoints, future research directions exploring the robustness and clinical viability of cancer nanotheranostics through various strategies to enhance the biocompatibility of theranostic nanoparticles are summarised.

Synergistically Enhancing the Therapeutic Effect on Cancer, via Asymmetric Bioinspired Materials

The undesirable side effects of conventional chemotherapy are one of the major problems associated with cancer treatment. Recently, with the development of novel nanomaterials, tumor-targeted therapies have been invented in order to achieve more specific cancer treatment with reduced unfavorable side effects of chemotherapic agents on human cells. However, the clinical application of nanomedicines has some shortages, such as the reduced ability to cross biological barriers and undesirable side effects in normal cells. In this order, bioinspired materials are developed to minimize the related side effects due to their excellent biocompatibility and higher accumulation therapies. As bioinspired and biomimetic materials are mainly composed of a nanometric functional agent and a biologic component, they can possess both the physicochemical properties of nanomaterials and the advantages of biologic agents, such as prolonged circulation time, enhanced biocompatibility, immune modulation, and specific targeting for cancerous cells. Among the nanomaterials, asymmetric nanomaterials have gained attention as they provide a larger surface area with more active functional sites compared to symmetric nanomaterials. Additionally, the asymmetric nanomaterials are able to function as two or more distinct components due to their asymmetric structure. The mentioned properties result in unique physiochemical properties of asymmetric nanomaterials, which makes them desirable materials for anti-cancer drug delivery systems or cancer bio-imaging systems. In this review, we discuss the use of bioinspired and biomimetic materials in the treatment of cancer, with a special focus on asymmetric nanoparticle anti-cancer agents.

Applications of Metallic Nanoparticles in the Skin Cancer Treatment

Skin cancer is one of leading cancers globally, divided into two major categories including melanoma and nonmelanoma. Skin cancer is a global concern with an increasing trend, hence novel therapies are essential. The local treatment strategies play a key role in skin cancer therapy. Nanoparticles (NPs) exert potential applications in medicine with huge advantages and have the ability to overcome common chemotherapy problems. Recently, NPs have been used in nanomedicine as promising drug delivery systems. They can enhance the solubility of poorly water-soluble drugs, improve pharmacokinetic properties, modify bioavailability, and reduce drug metabolism. The high-efficient, nontoxic, low-cost, and specific cancer therapy is a promising goal, which can be achieved by the development of nanotechnology. Metallic NPs (MNPs) can act as important platforms. MNPs development seeks to enhance the therapeutic efficiency of medicines through site specificity, prevention of multidrug resistance, and effective delivery of therapeutic factors. MNPs are used as potential arms in the case of cancer recognition, such as Magnetic Resonance Imaging (MRI) and colloidal mediators for magnetic hyperthermia of cancer. The applications of MNPs in the cancer treatment studies are mostly due to their potential to carry a large dose of drug, resulting in a high concentration of anticancer drugs at the target site. Therefore, off-target toxicity and suffering side effects caused by high concentration of the drug in other parts of the body are avoided. MNPs have been applied as drug carriers for the of improvement of skin cancer treatment and drug delivery. The development of MNPs improves the results of many cancer treatments. Different types of NPs, such as inorganic and organic NPs have been investigated in vitro and in vivo for the skin cancer therapy. MNPs advantages mostly include biodegradability, electrostatic charge, good biocompatibility, high drug payload, and low toxicity. However, the use of controlled-release systems stimulated by electromagnetic waves, temperature, pH, and light improves the accumulation in tumor tissues and improves therapeutic outcomes. This study (2019-2022) is aimed at reviewing applications of MNPs in the skin cancer therapy.

Hydrophobically Modified Abelmoschus esculentus Polysaccharide Based Nanoparticles and Applications: A Review

Nanomaterials are indeed a nanoscale technology that deals with the creation, evaluation, fabrication, and utilization of systems at the nanometre scale by manipulating their size and shape. We consider natural polysaccharides such as promising polysaccharides, which are biodegradable, nontoxic, abundant, and inexpensive bio-polymeric precursors for preparing the materials of choice in various industries. The aim is to review different methods to produce hydrophobically modified Abelmoschus esculentus nanoparticles and study the evaluation processes of these nanoparticles as given in the literature. It proved the benefits of derivatives of gum by introducing different chemical groups. The chemical functionalization of gum mainly includes the esterification, etherification, and crosslinking reactions of the hydroxyl groups and contains a special fibre which takes sugar levels in the blood under control, providing a sugar quantity suitable for the bowels. Okra contains mucilage that helps remove poisonous chemicals and bad cholesterol, often overloads the liver. Recovering from psychological conditions, like depression, general weakness, and joint healthiness can be done with Okra. Someone additionally applied it for pulmonary inflammation, bowel irritation, and sore throat. Purgative properties okra possesses are beneficial for bowel purification. It is used to counteract the acids. Fibre okra contains a valuable nutrient for intestinal microorganisms and ensures proper intestine functionality. It also protects the mucosa of the digestive tract by covering them with an extra layer because of its alkaline nature. Nanotechnology has emerged as a critical component of pharmaceutics, with many applications in drug carriers of interest aimed at improving drug clinical outcomes such as cancer, diabetes mellitus, wound care management, atopic dermatitis, cosmeceutical, etc. Beneficial outcomes of this review are discussed briefly.

Topical Delivery of Elastic Liposomal Vesicles for Treatment of Middle and Inner Ear Diseases

We present a topical drug delivery mechanism through the ear canal to the middle and inner ear using liposomal nanoparticles without disrupting the integrity of the tympanic membrane. The current delivery method provides a noninvasive and safer alternative to transtympanic membrane injections, ear tubes followed by ear drops administration, and systemic drug formulations. We investigate the capability of liposomal NPs, particularly transfersomes (TLipo), used as drug delivery vesicles to penetrate the tympanic membrane (TM) and round window membrane (RWM) with high affinity, specificity, and retention time. The TLipo is applied to the ear canal and found to pass through the tympanic membrane quickly in 3 h post drug administration. They are identified in the middle ear cavity 6 h and in the inner ear 24 h after drug administration. We performed cytotoxicity in vitro and ototoxicity in vivo studies. Cell viability shows no significant difference between the applied TLipo concentration and control. Furthermore, auditory brainstem response (ABR) reveals no hearing loss in 1 week and 1 month post-administration. Immunohistochemistry results demonstrate no evidence of hair cell loss in the cochlea at 1 month following TLipo administration. Together, the data suggested that TLipo can be used as a vehicle for topical drug delivery to the middle ear and inner ear.

PLGA-PVA-PEG Single Emulsion Method as a Candidate for Aminolevulinic Acid (5-ALA) Encapsulation: Laboratory Scaling up and Stability Evaluation

One of the most widely used molecules used for photodynamic therapy (PDT) is 5-aminolevulinic acid (5-ALA), a precursor in the synthesis of tetrapyrroles such as chlorophyll and heme. The 5-ALA skin permeation is considerably reduced due to its hydrophilic characteristics, decreasing its local bioavailability and therapeutic effect. For this reason, five different systems containing polymeric particles of poly [D, L–lactic–co–glycolic acid (PLGA)] were developed to encapsulate 5-ALA based on single and double emulsions methodology. All systems were standardized (according to the volume of reagents and mass of pharmaceutical ingredients) and compared in terms of laboratory scaling up, particle formation and stability over time. UV-VIS spectroscopy revealed that particle absorption/adsorption of 5-ALA was dependent on the method of synthesis. Different size distribution was observed by DLS and NTA techniques, revealing that 5-ALA increased the particle size. The contact angle evaluation showed that the system hydrophobicity was dependent on the surfactant and the 5-ALA contribution. The FTIR results indicated that the type of emulsion influenced the particle formation, as well as allowing PEG functionalization and interaction with 5-ALA. According to the ¹H-NMR results, the 5-ALA reduced the T1 values of polyvinyl alcohol (PVA) and PLGA in the double emulsion systems due to the decrease in molecular packing in the hydrophobic region. The results indicated that the system formed by single emulsion containing the combination PVA–PEG presented greater stability with less influence from 5-ALA. This system is a promising candidate to successfully encapsulate 5-ALA and achieve good performance and specificity for in vitro skin cancer treatment.

Antitumor/anti-angiogenesis efficacy of epigallocatechin gallate nanoformulated with antioxidant in melanoma

Aim: Epigallocatechin gallate (EGCG) derived from green tea has poor stability; therefore, to enhance its bioavailability and anticancer efficiency, we synthesized three different nanoformulations. We hypothesized that these three nanoformulations of EGCG (nano-EGCG) would enhance EGCG’s stability and improve its anticancer and antiangiogenic activity against melanoma compared with free EGCG. Methods: We prepared nano-EGCG using a copolymerization method with the UV blocker ZnO and the antioxidants lycopene and olive oil. Results: The different nano-EGCG formulation exhibited improved EGCG stability and greater suppression of melanoma growth than free EGCG. Nanoformulation preparation methods efficiently prevented the loss of EGCG activity and are a favorable approach for the treatment of melanoma. Conclusion: Nano-EGCG formulations had enhanced stability and produced greater suppression of melanoma tumor growth and angiogenesis compared with free EGCG.

Integrated approaches to testing and assessment for grouping nanomaterials following dermal exposure

Exposure to different nanoforms (NFs) via the dermal route is expected in occupational and consumer settings and thus it is important to assess their dermal toxicity and the contribution of dermal exposure to systemic bioavailability. We have formulated four grouping hypotheses for dermal toxicity endpoints which allow NFs to be grouped to streamline and facilitate risk assessment. The grouping hypotheses are developed based on insight into how physicochemical properties of NFs (i.e. composition, dissolution kinetics, size, and flexibility) influence their fate and hazard following dermal exposure. Each hypothesis is accompanied by a tailored Integrated Approach to Testing and Assessment (IATA) that is structured as a decision tree and tiered testing strategies (TTS) for each relevant question (at decision nodes) that indicate what information is needed to guide the user to accept or reject the grouping hypothesis. To develop these hypotheses and IATAs, we gathered and analyzed existing information on skin irritation, skin sensitization, and dermal penetration of NFs from the published literature and performed experimental work to generate data on NF dissolution in sweat simulant fluids. We investigated the dissolution of zinc oxide and silicon dioxide NFs in different artificial sweat fluids, demonstrating the importance of using physiologically relevant conditions for dermal exposure. All existing and generated data informed the formulation of the grouping hypotheses, the IATAs, and the design of the TTS. It is expected that the presented IATAs will accelerate the NF risk assessment for dermal toxicity via the application of read-across.

The Effect of Encapsulated Apigenin Nanoparticles on HePG-2 Cells through Regulation of P53

Apigenin (Ap) is one of the most important natural flavonoids that has potent anticancer activity. This study was designed, for the first time, to load Ap into chitosan to improve its hydrophobicity and then it was coated with albumin-folic acid to increase its stability and bioavailability and to target cancer cells. The newly developed encapsulated Ap (Ap-CH-BSA-FANPs) was characterized and tested in vitro. The zeta potential of −17.0 mV was within the recommended range (−30 mV to +30 mV), indicating that encapsulated apigenin would not quickly settle and would be suspended. The in vitro results proved the great anticancer activity of the encapsulated apigenin on HePG-2 cells compared to pure Ap. The treated HePG-2 cells with Ap-CH-BSA-FANPs demonstrated the induction of apoptosis by increasing p53 gene expression, arresting the cell cycle, increasing caspase-9 levels, and decreasing both the MMP9 gene and Bcl-2 protein expression levels. Moreover, the higher antioxidant activity of the encapsulated apigenin treatment was evident through increasing SOD levels and decreasing the CAT concentration. In conclusion, the Ap-CH-BSA-FANPs were easy to produce with low coast, continued drug release, good loading capacity, high solubility in physiological pH, and were more stable than the formerly Ap-loaded liposomes or PLGA. Moreover, Ap-CH-BSA-FANPs may be a promising chemotherapeutic agent in the treatment of HCC.

Skin cancer, including related pathways and therapy and the role of luteolin derivatives as potential therapeutics

Cutaneous malignant melanoma is the fastest growing and the most aggressive form of skin cancer that is diagnosed. However, its incidence is relatively scarce compared to the highest mortality rate of all skin cancers. The much more common skin cancers include nonmelanoma malignant skin cancers. Moreover, over the past several decades, the frequency of all skin cancers has increased much more dynamically than that of almost any other type of cancer. Among the available therapeutic options for skin cancers, chemotherapy used immediately after the surgical intervention has been an essential element. Unfortunately, the main problem with conventional chemopreventive regimens involves the lack of response to treatment and the associated side effects. Hence, there is a need for much more effective anticancer drugs. Correspondingly, the targeted alternatives have involved phytochemicals, which are safer chemotherapeutic agents and exhibit competitive anticancer activity with high therapeutic efficacy. Among polyphenolic compounds, some flavonoids and their derivatives, which are mostly found in medicinal plants, have been demonstrated to influence the modulation of signaling pathways at each stage of the carcinogenesis process, which is also important in the context of skin cancers. Hence, this review focuses on an exhaustive overview of the therapeutic effects of luteolin and its derivatives in the treatment and prevention of skin cancers. The bioavailability and structure–activity relationships of luteolin derivatives are also discussed. This review is the first such complete account of all of the scientific reports concerning this particular group of natural compounds that target a specific area of neoplastic diseases.

Oxidative Stress-Related Mechanisms in Melanoma and in the Acquired Resistance to Targeted Therapies

Melanoma is a highly aggressive cancer with the poorest prognosis, representing the deadliest form of skin cancer. Activating mutations in BRAF are the most frequent genetic alterations, present in approximately 50% of all melanoma cases. The use of specific inhibitors towards mutant BRAF variants and MEK, a downstream signaling target of BRAF in the MAPK pathway, has significantly improved progression-free and overall survival in advanced melanoma patients carrying BRAF mutations. Nevertheless, despite these improvements, resistance still develops within the first year of therapy in around 50% of patients, which is a significant problem in managing BRAF-mutated advanced melanoma. Understanding these mechanisms is one of the mainstreams of the research on BRAFi/MEKi acquired resistance. Both genetic and epigenetic mechanisms have been described. Moreover, in recent years, oxidative stress has emerged as another major force involved in all the phases of melanoma development, from initiation to progression until the onsets of the metastatic phenotype and chemoresistance, and has thus become a target for therapy. In the present review, we discuss the current knowledge on oxidative stress and its signaling in melanoma, as well as the oxidative stress-related mechanisms in the acquired resistance to targeted therapies.

Development, Characterization, and Evaluation of α-Mangostin-Loaded Polymeric Nanoparticle Gel for Topical Therapy in Skin Cancer

The aim of this study was to prepare and evaluate α-mangostin-loaded polymeric nanoparticle gel (α-MNG-PLGA) formulation to enhance α-mangostin delivery in an epidermal carcinoma. The poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were developed using the emulsion-diffusion-evaporation technique with a 3-level 3-factor Box-Behnken design. The NPs were characterized and evaluated for particle size distribution, zeta potential (mV), drug release, and skin permeation. The formulated PLGA NPs were converted into a preformed carbopol gel base and were further evaluated for texture analysis, the cytotoxic effect of PLGA NPs against B16-F10 melanoma cells, and in vitro radical scavenging activity. The nanoscale particles were spherical, consistent, and average in size (168.06 ± 17.02 nm), with an entrapment efficiency (EE) of 84.26 ± 8.23% and a zeta potential of -25.3 ± 7.1 mV. Their drug release percentages in phosphate-buffered solution (PBS) at pH 7.4 and pH 6.5 were 87.07 ± 6.95% and 89.50 ± 9.50%, respectively. The release of α-MNG from NPs in vitro demonstrated that the biphasic release system, namely, immediate release in the initial phase, was accompanied by sustained drug release. The texture study of the developed α-MNG-PLGA NPs gel revealed its characteristics, including viscosity, hardness, consistency, and cohesiveness. The drug flux from α-MNG-PLGA NPs gel and α-MNG gel was 79.32 ± 7.91 and 16.88 ± 7.18 µg/cm2/h in 24 h, respectively. The confocal study showed that α-MNG-PLGA NPs penetrated up to 230.02 µm deep into the skin layer compared to 15.21 µm by dye solution. MTT assay and radical scavenging potential indicated that α-MNG-PLGA NPs gel had a significant cytotoxic effect and antioxidant effect compared to α-MNG gel (p < 0.05). Thus, using the developed α-MNG-PLGA in treating skin cancer could be a promising approach.

Site-Specific Vesicular Drug Delivery System for Skin Cancer: A Novel Approach for Targeting

Skin cancer, one of the most prevalent cancers worldwide, has demonstrated an alarming increase in prevalence and mortality. Hence, it is a public health issue and a high burden of disease, contributing to the economic burden in its treatment. There are multiple treatment options available for skin cancer, ranging from chemotherapy to surgery. However, these conventional treatment modalities possess several limitations, urging the need for the development of an effective and safe treatment for skin cancer that could provide targeted drug delivery and site-specific tumor penetration and minimize unwanted systemic toxicity. Therefore, it is vital to understand the critical biological barriers involved in skin cancer therapeutics for the optimal development of the formulations. Various nanocarriers for targeted delivery of chemotherapeutic drugs have been developed and extensively studied to overcome the limitations faced by topical conventional dosage forms. A site-specific vesicular drug delivery system appears to be an attractive strategy in topical drug delivery for the treatment of skin malignancies. In this review, vesicular drug delivery systems, including liposomes, niosomes, ethosomes, and transfersomes in developing novel drug delivery for skin cancer therapeutics, are discussed. Firstly, the prevalence statistics, current treatments, and limitations of convention dosage form for skin cancer treatment are discussed. Then, the common type of nanocarriers involved in the research for skin cancer treatment are summarized. Lastly, the utilization of vesicular drug delivery systems in delivering chemotherapeutics is reviewed and discussed, along with their beneficial aspects over other nanocarriers, safety concerns, and clinical aspects against skin cancer treatment.

The Impact of Improving Dermal Permeation on the Efficacy and Targeting of Liposome Nanoparticles as a Potential Treatment for Breast Cancer

Breast cancer is the most frequent malignancy in women. This work focuses on developing deformable liposomes as a potential carrier for breast cancer treatment and studying the impact of improving dermal permeation on the efficacy and targeting of liposomes. Raloxifene (RXF), an oestrogen antagonist, was used as a model drug. Using Box-Behnken design, different formulations of RXF-loaded deformable liposome (RLDL) were prepared using different propylene glycol, phospholipid and cholesterol concentrations. The percentage of entrapment efficiency (Y₁), particle size (Y₂), zeta potential (Y₃) and steady-state flux (Y₄) of the prepared formulations were all evaluated. Y₁ and Y₄ were significantly increased and Y₂ and Y₃ were significantly decreased when the propylene glycol concentration was increased. The optimization was obtained and the optimum formulation was that including phospholipid (1.40% w/w), cholesterol (0.15% w/w) and propylene glycol (10% v/v). The selected optimum formulation displayed a % EE of 78.34 ± 1.04% with a steady-state flux of 4.21 ± 0.02 µg/cm²/h. In order to investigate bioavailability, antitumor effectiveness and permeation, the optimum formulation was selected and included in a carbopol gel. The optimum gel formulation had 2.77 times higher bioavailability and, as a result, considerable antitumor action as compared to oral RXF. In conclusion, optimum RLDL gel may be an effective breast cancer treatment.

Nanovaccine: an emerging strategy

INTRODUCTION

Vaccination is so far the most effective way of eradicating infections. Rapidly emerging drug resistance against infectious diseases and chemotherapy-related toxicities in cancer warrant immediate vaccine development to save mankind. Subunit vaccines alone, however, fail to elicit sufficiently strong and long-lasting protective immunity against deadly pathogens. Nanoparticle (NP)-based delivery vehicles like microemulsions, liposomes, virosomes, nanogels, micelles and dendrimers offer promising strategies to overcome limitations of traditional vaccine adjuvants. Nanovaccines can improve targeted delivery, antigen presentation, stimulation of body's innate immunity, strong T cell response combined with safety to combat infectious diseases and cancers. Further, nanovaccines can be highly beneficial to generate effective immutherapeutic formulations against cancer.

AREAS COVERED

This review summarizes the emerging nanoparticle strategies highlighting their success and challenges in preclinical and clinical trials in infectious diseases and cancer. It provides a concise overview of current nanoparticle-based vaccines, their adjuvant potential and their cellular delivery mechanisms.

EXPERT OPINION

The nanovaccines (50-250 nm in size) are most efficient in terms of tissue targeting, prolonged circulation and preferential uptake by the professional APCs chiefly due to their small size. More rational designing, improved antigen loading, extensive functionalization and targeted delivery are some of the future goals of ideal nanovaccines.

Improving the Antitumor Activity and Bioavailability of Sonidegib for the Treatment of Skin Cancer

Throughout the United States and the world, skin cancer is the most frequent form of cancer. Sonidegib (SNG) is a hedgehog inhibitor that has been used for skin cancer treatment. However, SNG has low bioavailability and is associated with resistance. The focus of this work is to enhance bioavailability, anti-tumor efficacy and targeting of SNG via developing ethosome gel as a potential treatment for skin cancer. SNG-loaded ethosomes formulation was prepared and characterized in vitro by %entrapment efficiency (%EE), vesicle size, morphology, %release and steady-state flux. The results showed that the prepared formulation was spherical nanovesicles with a %EE of 85.4 ± 0.57%, a particle size of 199.53 ± 4.51 nm and a steady-state flux of 5.58 ± 0.08 µg/cm2/h. In addition, SNG-loaded ethosomes formulation was incorporated into carbopol gel to study the anti-tumor efficacy, localization and bioavailability in vivo. Compared with oral SNG, the formulation showed 3.18 times higher relative bioavailability and consequently significant anti-tumor activity. In addition, this formulation showed a higher rate of SNG penetration in the skin's deep layers and passive targeting in tumor cells. Briefly, SNG-loaded ethosome gel can produce desirable therapeutic benefits for treatment of skin cancer.

Carbon dots for cancer nanomedicine: a bright future

Cancer remains one of the main causes of death in the world. Early diagnosis and effective cancer therapies are required to treat this pathology. Traditional therapeutic approaches are limited by lack of specificity and systemic toxicity. In this scenario, nanomaterials could overcome many limitations of conventional approaches by reducing side effects, increasing tumor accumulation and improving the efficacy of drugs. In the past few decades, carbon nanomaterials (i.e., fullerenes, carbon nanotubes, and carbon dots) have attracted significant attention of researchers in various scientific fields including biomedicine due to their unique physical/chemical properties and biological compatibility and are among the most promising materials that have already changed and will keep changing human life. Recently, because of their functionalization and stability, carbon nanomaterials have been explored as a novel tool for the delivery of therapeutic cancer drugs. In this review, we present an overview of the development of carbon dot nanomaterials in the nanomedicine field by focusing on their synthesis, and structural and optical properties as well as their imaging, therapy and cargo delivery applications.

Skin cancer therapeutics: nano-drug delivery vectors—present and beyond

Background

Skin cancers are among the widely prevalent forms of cancer worldwide. The increasing industrialization and accompanied environmental changes have further worsened the skin cancer statistics. The stern topical barrier although difficult to breach is a little compromised in pathologies like skin cancer. The therapeutic management of skin cancers has moved beyond chemotherapy and surgery.

Main body of the abstract

The quest for a magic bullet still prevails, but topical drug delivery has emerged as a perfect modality for localized self-application with minimal systemic ingress for the management of skin cancers. Advances in topical drug delivery as evidenced by the exploration of nanocarriers and newer technologies like microneedle-assisted/mediated therapeutics have revolutionized the paradigms of topical treatment. The engineered nanovectors have not only been given the liberty to experiment with a wide-array of drug carriers with very distinguishing characteristics but also endowed them with target specificity. The biologicals like nucleic acid-based approaches or skin penetrating peptide vectors are another promising area of skin cancer therapeutics which has demonstrated potential in research studies. In this review, a panoramic view is presented on the etiology, therapeutic options, and emerging drug delivery modalities for skin cancer.

Short conclusion

Nanocarriers have presented innumerable opportunities for interventions in skin cancer therapeutics. Challenge persists for the bench to bedside translation of these highly potential upcoming therapeutic strategies.

Graphic abstract

Formulations Based on Drug Loaded Aptamer-Conjugated Liposomes as a Viable Strategy for the Topical Treatment of Basal Cell Carcinoma-In Vitro Tests

Topical liposomal drug formulations containing AS1411-aptamer conjugated liposomes were designed to deliver in a sustained way the 5-fluorouracil to the tumor site but also to increase the compliance of patients with basal cell carcinoma. The 5-fluorouracil penetrability efficiency through the Strat-M membrane and the skin irritation potential of the obtained topical liposomal formulations were evaluated in vitro and the Korsmeyer Peppas equation was considered as the most appropriate to model the drug release. Additionally, the efficiency of cytostatic activity for targeted antitumor therapy and the hemolytic capacity were performed in vitro. The obtained results showed that the optimal liposomal formulation is a crosslinked gel based on sodium alginate and hyaluronic acid containing AS1411-aptamer conjugated liposomes loaded with 5-fluorouracil, which appeared to have favorable biosafety effects and may be used as a new therapeutic approach for the topical treatment of basal cell carcinoma.

Quality by Design for Development, Optimization and Characterization of Brucine Ethosomal Gel for Skin Cancer Delivery

Natural products have been extensively used for treating a wide variety of disorders. In recent times, Brucine (BRU) as one of the natural medications extracted from seeds of nux vomica, was investigated for its anticancer activity. As far as we know, this is the first study on BRU anticancer activity against skin cancer. Thus, the rational of this work was implemented to develop, optimize and characterize the anticancer activity of BRU loaded ethosomal gel. Basically, thin film hydration method was used to formulate BRU ethosomal preparations, by means of Central composite design (CCD), which were operated to construct (3²) factorial design. Two independent variables were designated (phospholipid percentage and ethanol percentage) with three responses (vesicular size, encapsulation efficiency and flux). Based on the desirability function, one formula was selected and incorporated into HPMC gel base to develop BRU loaded ethosomal gel. The fabricated gel was assessed for all physical characterization. In-vitro release investigation, ex-vivo permeation and MTT calorimetric assay were performed. BRU loaded ethosomal gel exhibited acceptable values for the characterization parameters which stand proper for topical application. In-vitro release investigation was efficiently prolonged for 6 h. The flux from BRU loaded ethosome was enhanced screening optimum SSTF value. Finally, in-vitro cytotoxicity study proved that BRU loaded ethosomal gel significantly improved the anticancer activity of the drug against A375 human melanoma cell lines. Substantially, the investigation proposed a strong motivation for further study of the lately developed BRU loaded ethosomal gel as a prospective therapeutic strategy for melanoma treatment.

Protoporphyrin IX (PpIX) loaded PLGA nanoparticles for topical Photodynamic Therapy of melanoma cells

INTRODUCTION

Nanoparticles (Np) can increase drug efficacy and overcome problems associated with solubility and aggregation in a solution of PpIX.

PURPOSE

Evaluate if Np interferes in the photophysical and photobiological capacity of the PpIX comparing with free PpIX intended for topical PDT of melanoma.

METHODS

In vitro photophysical evaluation of Np-PpIX was carried out through singlet oxygen (₁O²) quantum yield. In vitro cytotoxicity and phototoxicity assays have used murine melanoma cell culture.

RESULTS

The quantum yield of singlet oxygen has shown that Np did not influence the formation capacity of this reactive species. In the dark, all PpIX-Nps concentrations were less cytotoxic compared to free drugs. At a higher light dose (1500 mJ.cm²) 3.91 μg / mL PpIX had similar % viable cells for free and Np (∼34 %) meaning Nps did not interfere in the photodynamic effect of PpIX. However, at 7.91 μg / mL the phototoxicity increased for both (5.8 % viable cells for free versus 21.7 % for Nps). Despite the higher phototoxicity of free PpIX at this concentration, greater cytotoxicity in the dark was obtained (∼49 % viable cells for free versus ∼90.6 % Np) which means Nps protect the tumor tissue from the photodynamic action of PpIX.

CONCLUSIONS

Np is a potential delivery system for melanoma skin cancer, since it maintained the photophysical properties of PpIX and excellent in vitro phototoxicity effect against melanoma cells, reducing cell viability ∼80 % (7.91 μg / mL PpIX in Nps) and provides safe PDT (due to lower cytotoxicity in the dark).

Pathogenesis of Keratinocyte Carcinomas and the Therapeutic Potential of Medicinal Plants and Phytochemicals

Keratinocyte carcinoma (KC) is a form of skin cancer that develops in keratinocytes, which are the predominant cells present in the epidermis layer of the skin. Keratinocyte carcinoma comprises two sub-types, namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This review provides a holistic literature assessment of the origin, diagnosis methods, contributing factors, and current topical treatments of KC. Additionally, it explores the increase in KC cases that occurred globally over the past ten years. One of the principal concepts highlighted in this article is the adverse effects linked to conventional treatment methods of KC and how novel treatment strategies that combine phytochemistry and transdermal drug delivery systems offer an alternative approach for treatment. However, more in vitro and in vivo studies are required to fully assess the efficacy, mechanism of action, and safety profile of these phytochemical based transdermal chemotherapeutics.

Apigenin role as cell-signaling pathways modulator: implications in cancer prevention and treatment

Cancer is a complex disease orchestrated by various extrinsic and intrinsic pathways. In recent years, there has been a keen interest towards the development of natural extracts-based cancer therapeutics with minimum adverse effects. In pursuit of effective strategy, a wide variety of natural products-derived compounds have been addressed for their anticancer effects. Apigenin is a naturally-occurring flavonoid present abundantly in various fruits and vegetables. Decades of research have delineated the pharmacological and biological properties of apigenin. Specifically, the apigenin-mediated anticancer activities have been documented in various types of cancer, but the generalized scientific evidence encompassing various molecular interactions and processes, such as regulation of the apoptotic machinery, aberrant cell signaling and oncogenic protein network have not been comprehensively covered. In this sense, in this review we have attempted to focus on the apigenin-mediated regulation of oncogenic pathways in various cancers. We have also addressed the cutting-edge research which has unveiled the remarkable abilities of apigenin to interact with microRNAs to modulate key cellular processes, with special emphasis on the nano-formulations of apigenin that can help their targeted delivery and can be a therapeutic solution for the treatment of various cancers.

Non-invasive transdermal delivery of chemotherapeutic molecules in vivo using superparamagnetic iron oxide nanoparticles

Background

The skin is both a target and a potential conduit for the delivery of drugs, but its cornified cell layer resists penetration by most molecules. This study investigated the potential of superparamagnetic iron oxide nanoparticles to facilitate the transdermal delivery of anticancer agents.

Results

Chemotherapeutic cancer drugs were applied with or without nanoparticles to the skin of hairless mice, and their ability to penetrate the skin was assessed using fluorescence microscopy and tumor growth. Nanoparticles enhanced the penetration of the skin by doxorubicin and 5-fluorouracil as determined by fluorescence microscopy and growth retardation of experimental melanoma in immunocompetent, syngeneic mice. This drug enhancement did not require conjugation or encapsulation of the drugs by the nanoparticles—simple co-administration sufficed. Nanoparticles applied topically to melanomas increased the cytotoxicity and immune cell infiltration induced by co-administered 5-fluorouracil, and also reduced vascularization of the tumors independently of 5-fluorouracil.

Conclusion

Correctly formulated superparamagnetic iron oxide nanoparticles can facilitate the chemotherapeutic effectiveness of cytotoxic drugs on skin tumors by both increasing their transdermal penetration and ameliorating host–tumor interactions. This enhancement of skin penetration occurs without the need for conjugation or encapsulation of the co-administered drugs, and so will likely be applicable to other drugs, also.

Analytical tools and evaluation strategies for nanostructured lipid carrier-based topical delivery systems

INTRODUCTION

The inception of nanostructured lipid carriers (NLCs) proved to be a revolutionary step toward the treatment of dermatological disorders. To uncover its true potential, it is imperative that the system be characterized and evaluated comprehensively.

AREAS COVERED

The present review has been written to furnish an in-depth account of analytical tools and evaluation procedures under one roof. Besides discussing the challenges of topical delivery and benefits of NLCs, the paper elaborates on their physicochemical characterization. Further, in vitro evaluation of NLCs for dermatological benefits, followed by their evaluation in a hydrogel/cream base is covered. Lastly, disease-specific evaluation of NLC-based formulations is presented.

EXPERT OPINION

The research endeavors for NLCs have largely focused on the fabrication of NLCs for different bioactives. However, scientific efforts should be aimed toward the lesser explored realm of NLCs, i.e. exploitation of analytical techniques, such as Parelectric spectroscopy, Electron Spin Resonance, and Nuclear Magnetic Resonance spectroscopy. NLCs have been proven for their potential to foster the therapeutic modalities applicable to cutaneous disorders. More attention needs to be devoted to their evaluation for disease-specific parameters. The futuristic steps must involve clinical studies, to lay the path for their commercialization.

Therapeutic strategies and potential implications of silver nanoparticles in the management of skin cancer

Skin cancer (SC) is the most common carcinoma affecting 3 million people annually in the United States and millions of people worldwide. It is classified as melanoma SC (MSC) and non-melanoma SC (NMSC). NMSC represents approximately 80% of SC and includes squamous cell carcinoma and basal cell carcinoma. MSC, however, has a higher mortality rate than SC because of its ability to metastasize. SC is a major health problem in the United States with significant morbidity and mortality in the Caucasian population. Treatment options for SC include cryotherapy, excisional surgery, Mohs surgery, curettage and electrodessication, radiation therapy, photodynamic therapy, immunotherapy, and chemotherapy. Treatment is chosen based on the type of SC and the potential for side effects. Novel targeted therapies are being used with increased frequency for large tumors and for metastatic disease. A scoping literature search on PubMed, Google Scholar, and Cancer Registry websites revealed that traditional chemotherapeutic drugs have little effect against SC after the cancer has metastasized. Following an overview of SC biology, epidemiology, and treatment options, this review focuses on the mechanisms of advanced technologies that use silver nanoparticles in SC treatment regimens.

pH-Responsive Nanostructures Based on Surface Active Fatty Acid-Protic Ionic Liquids for Imiquimod Delivery in Skin Cancer Topical Therapy

For topical treatment of skin cancer, the design of pH-responsive nanocarriers able to selectively release the drug in the tumor acidic microenvironment represents a reliable option for targeted delivery. In this context, a series of newly synthesized surface-active fatty acid-protic ionic liquids (FA-PILs), based on tetramethylguanidinium cation and different natural hydrophobic fatty acid carboxylates, have been investigated with the aim of developing a pH-sensitive nanostructured drug delivery system for cutaneous administration in the skin cancer therapy. The capability of FA-PILs to arrange in micelles when combined with each other and with the non-ionic surfactant d-α-Tocopherol polyethylene glycol succinate (vitamin E TPGS) as well as their ability to solubilize imiquimod, an immuno-stimulant drug used for the treatment of skin cancerous lesions, have been demonstrated. The FA-PILs-TPGS mixed micelles showed pH-sensitivity, suggesting that the acidic environment of cancer cells can trigger nanostructures’ swelling and collapse with consequent rapid release of imiquimod and drug cytotoxic potential enhancement. The in vitro permeation/penetration study showed that the micellar formulation produced effective imiquimod concentrations into the skin exposed to acid environment, representing a potential efficacious and selective drug delivery system able to trigger the drug release in the tumor tissues, at lower and less irritating drug concentrations.

Stimuli-responsive and cellular targeted nanoplatforms for multimodal therapy of skin cancer

Interdisciplinary applications of nanopharmaceutical sciences have tremendous potential for enhancing pharmacokinetics, efficacy and safety of cancer therapy. The limitations of conventional therapeutic platforms used for skin cancer therapy have been largely overcome by the use of nanoplatforms. This review discusses various nanotechnological approaches experimented for the treatment of skin cancer. The review describes various polymeric, lipidic and inorganic nanoplatforms for efficient therapy of skin cancer. The stimuli-responsive nanoplatforms such as pH-responsive as well as temperature-responsive platforms have also been reviewed. Different strategies for potentiating the nanoparticles application for cancer therapy such as surface engineering, conjugation with drugs, stimulus-responsive and multimodal effect have also been discussed and compared with the available conventional treatments. Although, nanopharmaceuticals face challenges such as toxicity, cost and scale-up, efforts put-in to improve these drawbacks with continuous research would deliver exciting and promising results in coming days.