Liposomal systems as viable drug delivery technology for skin cancer sites with an outlook on lipid-based delivery vehicles and diagnostic imaging inputs for skin conditions'

Natural product-loaded lipid-based nanocarriers for skin cancer treatment: An overview

The skin is essential for body protection and regulating physiological processes. It is the largest organ and serves as the first-line barrier against UV radiation, harmful substances, and infections. Skin cancer is considered the most prevalent type of cancer worldwide, while melanoma skin cancer is having high mortality rates. Skin cancer, including melanoma and non-melanoma forms, is primarily caused by prolonged exposure to UV sunlight and pollution. Currently, treatments for skin cancer include surgery, chemotherapy, and radiotherapy. However, several factors hinder the effectiveness of these treatments, such as low efficacy, the necessity for high concentrations of active components to achieve a therapeutic effect, and poor drug permeation into the stratum corneum or lesions. Additionally, low bioavailability at the target site necessitates high doses, leading to skin irritation and further obstructing drug absorption through the stratum corneum. To overcome these challenges, recent research focuses on developing a medication delivery system based on nanotechnology as an alternative to this traditional approach. Nano-drug delivery systems have demonstrated great promise in treating skin cancer by providing a more effective means of delivering drugs with better stability and drug absorption. An overview of various lipid-based nanocarriers is given in this review article that are utilized to carry natural compounds to treat skin cancer.

Functionalized and Theranostic Lipidic and Tocosomal Drug Delivery Systems: Potentials and Limitations in Cancer Photodynamic Therapy

Photodynamic therapy (PDT) is a multidisciplinary area, which involves photophysics and photochemical sciences and plays an important role in cancer diagnosis and treatment. PDT involves a photo-activable drug called photosensitizer (PS), a specific wavelength of light and cellular compounds to produce toxic oxygen species in a much-localized way to destroy malignant tumors. Despite the various benefits of PDT, some PS-related limitations hinder its use as an ideal treatment option for cancer. To address these limitations (e.g., poor bioavailability, weak permeability, hydrophobicity, and aggregation), lipid-based and vesicular drug delivery systems have been employed. These carrier systems possess the ability to enhance the bioavailability, permeability, and solubility of the drug. Furthermore, they tend to load hydrophobic and lipophilic compounds and can be employed for an efficient and targeted drug delivery. The purpose of this review is to highlight the precise idea of PDT, the limitations of PDT related to PS, and the application of lipidic and tocosomal carriers in PDT for the treatment of various types of cancers. Liposomes, nanoliposomes, solid lipid nanoparticles, vesicular phospholipid gels, exosomes, transferosomes, and tocosomes are presented as commonly-employed vesicular drug carriers. Moreover, the amalgamation of cell-based drug delivery systems (CBDDS) with PDT holds considerable potential as an encouraging avenue in cancer treatment, especially in the context of immunotherapy.

Unravelling the success of transferosomes against skin cancer: Journey so far and road ahead

Skin cancer remains one of the most prominent types of cancer. Melanoma and non-melanoma skin cancer are commonly found together, with melanoma being the more deadly type. Skin cancer can be effectively treated with chemotherapy, which mostly uses small molecular medicines, phytoceuticals, and biomacromolecules. Topical delivery of these therapeutics is a non-invasive way that might be useful in effectively managing skin cancer. Different skin barriers, however, presented a major obstacle to topical cargo administration. Transferosomes have demonstrated significant potential in topical delivery by improving cargo penetration through the circumvention of diverse skin barriers. Additionally, the transferosome-based gel can prolong the residence of drug on the skin, lowering the frequency of doses and their associated side effects. However, the choice of appropriate transferosome compositions, such as phospholipids and edge activators, and fabrication technique are crucial for achieving improved entrapment efficiency, penetration, and regulated particle size. The present review discusses skin cancer overview, current treatment strategies for skin cancer and their drawbacks. Topical drug delivery against skin cancer is also covered, along with the difficulties associated with it and the importance of transferosomes in avoiding these difficulties. Additionally, a summary of transferosome compositions and fabrication methods is provided. Furthermore, topical delivery of small molecular drugs, phytoceuticals, and biomacromolecules using transferosomes and transferosomes-based gel in treating skin cancer is discussed. Thus, transferosomes can be a significant option in the topical delivery of drugs to manage skin cancer efficiently.

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Advances in liposomes loaded with photoresponse materials for cancer therapy

Cancer treatment is presently a significant challenge in the medical domain, wherein the primary modalities of intervention include chemotherapy, radiation therapy and surgery. However, these therapeutic modalities carry side effects. Photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as promising modalities for the treatment of tumors in recent years. Phototherapy is a therapeutic approach that involves the exposure of materials to specific wavelengths of light, which can subsequently be converted into either heat or Reactive Oxygen Species (ROS) to effectively eradicate cancer cells. Due to the hydrophobicity and lack of targeting of many photoresponsive materials, the use of nano-carriers for their transportation has been extensively explored. Among these nanocarriers, liposomes have been identified as an effective drug delivery system due to their controllability and availability in the biomedical field. By binding photoresponsive materials to liposomes, it is possible to reduce the cytotoxicity of the material and regulate drug release and accumulation at the tumor site. This article provides a comprehensive review of the progress made in cancer therapy using photoresponsive materials loaded onto liposomes. Additionally, the article discusses the potential synergistic treatment through the combination of phototherapy with chemo/immuno/gene therapy using liposomes.

Solid lipid-based nanoparticulate system for sustained release and enhanced in-vitro cytotoxic effect of 5-fluorouracil on skin Melanoma and squamous cell carcinoma

The present study aimed to prepare solid lipid-based nanoparticles (SLNs) using Precirol® ATO 5 as solid lipid and Poloxamer 188 and Tween 80 as surfactant and co-surfactant respectively, and SLNs-derived gel for sustained delivery, enhanced in-vitro cytotoxicity, enhanced cellular uptake of 5-FU and enhanced permeation of 5-FU across the skin. The 5-FU-loaded SLNs were prepared by the hot melt encapsulation method and converted into SLN-derived gel using a gelling agent (Carbopol 940). The 5-FU-loaded SLNs had a particle size in the range of 76.82±1.48 to 327±4.46 nm, zeta potential between -11.3±2.11 and -28.4±2.40 mV, and entrapment efficiency (%) in range of 63.46±1.13 and 76.08±2.42. The FTIR analysis depicted that there was no chemical interaction between 5-FU and formulation components. Differential scanning calorimetric analysis showed thermal stability of 5-FU in the nanoparticles and powdered X-ray diffraction analysis revealed successful incorporation of 5-FU in nanoparticles. The in-vitro release study of 5-FU-loaded SLNs showed biphasic release behavior with initial burst release followed by sustained release over 48 hr. The 5-FU-loaded SLNs showed a greater cytotoxic effect on skin melanoma (B16F10 cells) and squamous cell carcinoma (A-431 cells) as compared to free 5-FU drug solution after 48 hr. Flow cytometry and fluorescence microscopy displayed enhanced quantitative and qualitative cellular uptake of SLNs. The SLNs formulation showed acceptable safety and biocompatible profile after an acute toxicity study in Wistar rats. Moreover, ex-vivo permeation studies depicted 2.13±0.076 folds enhanced flux of 5-FU-loaded SLN derived gel compared to 5-FU plain gel, and skin retention studies revealed target efficiency (%) 2.54±0.03 of 5-FU-loaded SLN derived gel compared to 5-FU plain gel.

In vitro and Ex vivo Antioxidant Activity and Sustained Release Properties of Sinomenine-Loaded Liposomes-in-Hydrogel Biomaterials Simulating Cells-in-Extracellular Matrix

Sinomenine (SIN), a natural product, has been used to treat rheumatoid arthritis (RA) in China for thousands of years. SIN has been developed for the treatment of RA by way of tablets and injections, but both dosage forms have been associated with severe adverse reactions. Making SIN into liposomes-in-hydrogel biomaterials for external use has a good slow-release effect and can play an important role in avoiding the first-pass effect, gastrointestinal reaction, and increasing the local action time of drugs. SIN-loaded liposomes were formed by the thin-film dispersion method, then SIN-loaded liposomes-in-hydrogels were prepared by combining the SIN-L with hyaluronic acid (HA) hydrogels. In this paper, the basic characteristics, In vitro and Ex vivo release, and antioxidant activity of SIN-loaded liposomes-in-hydrogels were studied. The results showed that SIN-loaded liposomes-in-hydrogels have good sustained-release and antioxidant effects, and the preparation is expected to be a good biomaterial.

Oxygen-Generating Hydrogels Overcome Tumor Hypoxia to Enhance Photodynamic/Gas Synergistic Therapy

Hypoxic environment is a bottleneck of photodynamic therapy (PDT) in tumor treatment, as oxygen is the critical substrate for photosensitivity reaction. Herein, a sustained oxygen supply system based on cerium nanoparticles and hydrogel (GHCAC) was explored for enhanced synergistic PDT and gas therapy. Ceria nanoparticles were prepared as a drug carrier by self-assembly mediated by hyaluronic acid (HA), a targeting for CD44 on cervical cancer cells, followed by photosensitizer and l-arginine (l-Arg) loading. Then, the GHCAC system was developed by incorporating a prepared nanocarrier (HCePA) and O₂-evolving agent calcium peroxide (CaO₂) into the hydrogel (Gel) developed by a poloxamer. Gel in the system could moderately infiltrate H₂O to react with CaO₂ and generate sustained oxygen using the catalase-like activity of HCePA. The system could efficiently alleviate hypoxia in tumor environments for up to 7 days, meeting the "once injection, repeat irradiation" strategy and enhanced PDT efficacy. Besides, the generated singlet oxygen (¹O₂) in the PDT process could also oxidize l-Arg into high concentrations of nitric oxide for synergistic gas therapy. The developed oxygen supplied and drug delivery Gel system is a new strategy for synergistic PDT/gas therapy to overcome cervical cancer.

Nanocarriers for Skin Applications: Where Do We Stand?

Skin penetration of active molecules for treatment of diverse diseases is a major field of research owing to the advantages associated with the skin like easy accessibility, reduced systemic-derived side effects, and increased therapeutic efficacy. Despite these advantages, dermal drug delivery is generally challenging due to the low skin permeability of therapeutics. Although various methods have been developed to improve skin penetration and permeation of therapeutics, they are usually aggressive and could lead to irreversible damage to the stratum corneum. Nanosized carrier systems represent an alternative approach for current technologies, with minimal damage to the natural barrier function of skin. In this Review, the use of nanoparticles to deliver drug molecules, genetic material, and vaccines into the skin is discussed. In addition, nanotoxicology studies and the recent clinical development of nanoparticles are highlighted to shed light on their potential to undergo market translation.

Nanostructured systems increase the in vitro cytotoxic effect of bullfrog oil in human melanoma cells (A2058)

The aim of this work was to investigate the in vitro cytotoxic effect of previously developed nanocapsules, nanoemulsion, and microemulsion based on bullfrog oil (BFO) against human melanoma cells (A2058). The nanosystems were produced as described in previous studies and characterized according to droplet/particle distribution and zeta potential. The biocompatibility was evaluated by the determination of the hemolytic potential against human erythrocytes. The cytotoxicity assessment was based on MTT and cell death assays, determination of Reactive Oxygen Species (ROS) levels, and cell uptake. The nanosystems were successfully reproduced and showed hemolytic potential smaller than 10% at all oil concentrations (50 and 100 µg.mL^-1) (p < 0.05). The MTT assay revealed that the nanosystems decreased the mitochondrial activity up to 92 ± 2% (p < 0.05). The study showed that the free BFO induced cell apoptosis, while all the nanostructured systems caused cell death by necrosis associated with a ROS overproduction. This can be related to the increased ability of the nanostructured systems to deliver the BFO across all cellular compartments (membrane, cytoplasm, and nucleus). Finally, these results elucidate the in vitro BFO nanosystems cytotoxic effect against human melanoma cells (A2058), revealing the emulsified ones as the most cytotoxic systems. Overall, the findings suggest that the safety and antineoplastic activity of these systems can be further investigated by in vivo studies.

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.

Advanced nanomedicine approaches applied for treatment of skin carcinoma

Skin-cancer is the commonest malignancy affecting huge proportion of the population, reaching heights in terms of morbidity. The treatment strategies are presently focusing on surgery, radiation and chemotherapy, which eventually cause destruction to unaffected cells. To overcome this limitation, wide range of nanoscaled materials have been recognized as potential carriers for delivering selective response to cancerous cells and neoplasms. Nanotechnological approach has been tremendously exploited in several areas, owing to their functional nanometric dimensions. The alarming incidence of skin cancer engenders burdensome effects worldwide, which is further awakening innovational medicinal approaches, accompanying target specific drug delivery tools for coveted benefits to provide reduced toxicity and tackle proliferative episodes of skin cancer. The developed nanosystems for anti-cancer agents include liposomes, ethosomes, nanofibers, solid lipid nanoparticles and metallic nanoparticles, which exhibit pronounced outcomes for skin carcinoma. In this review, skin cancer with its sub-types is explained in nutshell, followed by compendium of specific nanotechnological tools presented, in addition to therapeutic applications of drug-loaded nano systems for skin cancer.

Repurposing of Drug Candidates for Treatment of Skin Cancer

Skin cancers are highly prevalent malignancies that affect millions of people worldwide. These include melanomas and nonmelanoma skin cancers. Melanomas are among the most dangerous cancers, while nonmelanoma skin cancers generally exhibit a more benign clinical pattern; however, they may sometimes be aggressive and metastatic. Melanomas typically appear in body regions exposed to the sun, although they may also appear in areas that do not usually get sun exposure. Thus, their development is multifactorial, comprising endogenous and exogenous risk factors. The management of skin cancer depends on the type; it is usually based on surgery, chemotherapy, immunotherapy, and targeted therapy. In this respect, oncological treatments have demonstrated some progress in the last years; however, current therapies still present various disadvantages such as little cell specificity, recurrent relapses, high toxicity, and increased costs. Furthermore, the pursuit of novel medications is expensive, and the authorization for their clinical utilization may take 10-15 years. Thus, repositioning of drugs previously approved and utilized for other diseases has emerged as an excellent alternative. In this mini-review, we aimed to provide an updated overview of drugs' repurposing to treat skin cancer and discuss future perspectives.

Impact of Quercetin Encapsulation with Added Phytosterols on Bilayer Membrane and Photothermal-Alteration of Novel Mixed Soy Lecithin-Based Liposome

This study used highly lipophilic agents with an aim to increase the oxidant inhibitory activity and enhance photothermal stability of a novel mixed soy lecithin (ML)-based liposome by changing the composition of formulation within the membrane. Specifically, the development and optimization of the liposome intended for improving Trolox equivalent antioxidant capacity (TEAC) value and %TEAC loss was carried out by incorporating a natural antioxidant, quercetin (QU). In this context, a focus was set on QU encapsulation in ML-based liposomes and the concentration-dependent solubility of QU was investigated and calculated as encapsulation efficiency (EE). To explore the combined effects of the incorporation of plant sterols on the integrity and entrapment capacity of mixed phospholipid vesicles, conjugation of two types of phytosterols (PSs), namely β-sitosterol (βS) and stigmasterol (ST), to mixed membranes at different ratios was also performed. The EE measurement revealed that QU could be efficiently encapsulated in the stable ML-based liposome using 0.15 and 0.1 g/100 mL of βS and ST, respectively. The aforementioned liposome complex exhibited a considerable TEAC (197.23%) and enhanced TEAC loss (30.81%) when exposed to ultraviolet (UV) light (280-320 nm) over a 6 h duration. It appeared that the presence and type of PSs affect the membrane-integration characteristics as well as photodamage transformation of the ML-based liposome. The association of QU with either βS or ST in the formulation was justified by their synergistic effects on the enhancement of the EE of liposomes. Parallel to this, it was demonstrated that synergistic PS effects could be in effect in the maintenance of membrane order of the ML-based liposome. The findings presented in this study provided useful information for the development and production of stable QU-loaded ML-based liposomes for food and nutraceutical applications and could serve as a potential mixed lipids-based delivery system in the disease management using antioxidant therapy.

Development, Characterization and Use of Liposomes as Amphipathic Transporters of Bioactive Compounds for Melanoma Treatment and Reduction of Skin Inflammation: A Review

The skin is the largest organ in the human body, providing a barrier to the external environment. It is composed of three layers: epidermis, dermis and hypodermis. The most external epidermis is exposed to stress factors that may lead to skin conditions such as photo-aging and skin cancer. Some treatments for skin disease utilize the incorporation of drugs or bioactive compounds into nanocarriers known as liposomes. Liposomes are membranes whose sizes range from nano to micrometers and are composed mostly of phospholipids and cholesterol, forming similar structures to cell membranes. Thus, skin treatments with liposomes have lower toxicity in comparison to traditional treatment routes such as parenteral and oral. Furthermore, addition of edge activators to the liposomes decreases the rigidity of the bilayer structure making it deformable, thereby improving skin permeability. Liposomes are composed of an aqueous core and a lipidic bilayer, which confers their amphiphilic property. Thus, they can carry hydrophobic and hydrophilic compounds, even simultaneously. Current applications of these nanocarriers are mainly in the cosmetic and pharmaceutic industries. Nevertheless, new research has revealed promising results regarding the effectiveness of liposomes for transporting bioactive compounds through the skin. Liposomes have been well studied; however, additional research is needed on the efficacy of liposomes loaded with bioactive peptides for skin delivery. The objective of this review is to provide an up-to-date description of existing techniques for the development of liposomes and their use as transporters of bioactive compounds in skin conditions such as melanoma and skin inflammation. Furthermore, to gain an understanding of the behavior of liposomes during the process of skin delivery of bioactive compounds into skin cells.

Topical formulations containing aptamer-functionalized nanocapsules loaded with 5-fluorouracil - An innovative concept for the skin cancer therapy

New topical gel formulations based on sodium alginate and hyaluronic acid containing AS1411 aptamer-functionalized polymeric nanocapsules loaded with an antitumoral drug (5-Fluorouracil) were designed as an innovative approach for the skin cancer treatment. Several important analyses were used to characterize these obtained topical gel formulations, namely: rheological tests, permeation assays across Strat-M® artificial membrane, ex-vivo permeation assays across chicken skin membrane, haemolysis tests, skin irritation tests, in vitro cytotoxicity assay on human basal carcinoma cells and in vivo tests. Rheological tests revealed that apparent viscosity decreases with the increase of the shear rate, for analyzed samples, which demonstrates a shear thinning behavior. Low levels of hemolysis values which ranged between 0.03 and 0.55% suggested that the tested formulations did not induce red blood cell lysis.. The gel formulations containing nanocapsules loaded with 5-FU proved to be non-irritant. Furthermore, by study the ex-vivo diffusion properties across the chicken skin membrane, it was proved that nanoencapsulation enhance the permeability properties of 5-FU. In vitro cytotoxicity assay on TE 354.T (ATCC® CRL-7762™) human basal carcinoma cell line showed that the obtained formulations loaded with 5-Fluorouracil manifest an important cytotoxic effect. Finally, the presence of Langerhans CD68 cells-positive in the epidermis and epithelial sheath of dermal hair follicles suggests a specific activation, migration and retrieval of nanoparticles by these cells. Following the results obtained in this study we can appreciate that the obtained topical gel formulations have a favourable biosafety and good antitumor effects which makes them attractive for skin cancer treatment.

Liposome-based drug delivery of various anticancer agents of synthetic and natural product origin: a patent overview

Phospholipid-based liposomal vesicles are among the most effective delivery options currently available for various classes of anticancer drugs. The patents granted to inventions disclosing details on liposomal delivery module by the US Patent and Trademark Office, European Patent Office, and world patent holdings through WIPO (World Intellectual Property Organization) patenting have been sorted based upon liposome, and anticancer keywords within the abstract and claims sections of the patents for the period between 2000 and 2019, thereby disclosing novel liposome formulations encapsulating single, or combination of chemotherapeutic agents that have been far more chemically and physiologically stable, therapeutically efficacious, and comparatively less toxic than their nonliposomal free-drug counterparts. The added stability, site-specific transport, and payload delivery, enhanced bioavailability, fast body clearance, and biocompatibility together with the controlled and sustained delivery-related benefits claimed in the patent literature have been exclusively discussed with a focus on the last 5-year period.

Potential application of liposomal nanodevices for non-cancer diseases: an update on design, characterization and biopharmaceutical evaluation

Liposomes, lipid-based vesicular systems, have attracted major interest as a means to improve drug delivery to various organs and tissues in the human body. Recent literature highlights the benefits of liposomes for use as drug delivery systems, including encapsulating of both hydrophobic and hydrophilic cargos, passive and active targeting, enhanced drug bioavailability and therapeutic effects, reduced systemic side effects, improved cargo penetration into the target tissue and triggered contents release. Pioneering work of liposomes researchers led to introduction of long-circulating, ligand-targeted and triggered release liposomes, as well as, liposomes containing nucleic acids and vesicles containing combination of cargos. Altogether, these findings have led to widespread application of liposomes in a plethora of areas from cancer to conditions such as cardiovascular, neurologic, respiratory, skin, autoimmune and eye disorders. There are numerous review articles on the application of liposomes in treatment of cancer, which seems the primary focus, whereas other diseases also benefit from liposome-mediated treatments. Therefore, this article provides an illustrated detailed overview of liposomal formulations, in vitro characterization and their applications in different disorders other than cancer. Challenges and future directions, which must be considered to obtain the most benefit from applications of liposomes in these disorders, are discussed.

Bullfrog oil (Rana catesbeiana Shaw) induces apoptosis, in A2058 human melanoma cells by mitochondrial dysfunction triggered by oxidative stress

Bullfrog oil, an animal oil extracted from the adipose tissue of Rana catesbeiana Shaw, showed promising cytotoxic activity against melanoma cells and, therefore, has the potential to become a pharmaceutical active compound. However, there is a lack of information regarding the pathways involved in its pharmacological activity. Thus, the aim of this study was to investigate and elucidate the cytotoxic effect of this oil against A2058 human melanoma cells. The cytotoxic potential was evaluated by the MTT assay, the cell cycle analysis and the cell death assay. In addition, the apoptotic potential was investigated by (i) the DNA fragmentation using propidium iodide staining analysis, (ii) the evaluation of mitochondrial membrane potential and (iii) the determination of intracellular Reactive Oxygen Species (ROS) level. The results showed that the bullfrog oil was able to promote a time-dependent cytotoxic effect, decreasing cell viability to 38% after 72 h of treatment without affecting the cell cycle. Additionally, the bullfrog oil induced the apoptosis in A2058 cells, increasing up to 50 ± 13% of the intracellular ROS level, maintaining the DNA integrity and promoting an approximate decrease of 35 ± 5% in the mitochondrial membrane potential. It can be concluded that the in vitro cytotoxic effect of the bullfrog oil in A2058 human melanoma cells is mediated by oxidative stress that induces mitochondrial dysfunction, triggering the apoptosis. These unprecedented results highlight the pharmacological potential of bullfrog oil and provide important information to support studies on the development of new pharmaceutical products for complementary and alternative treatments for melanoma.

Synthesis, characterization and in vitro validation of a magnetic zeolite nanocomposite with T2-MRI properties towards theranostic applications

This study focusses on the development of a magnetic zeolite nanocomposite as a suitable platform towards the design of a theranostic system. Herein, we explored its ability to act as a T₂-MRI contrast enhancer when magnetic nanoparticles are incorporated in its structure.

Advances and challenges in liposome digestion: Surface interaction, biological fate, and GIT modeling

During the past 50 years, there has been increased interest in liposomes as carriers of pharmaceutical, cosmetic, and agricultural products. More recently, much progress has been made in the use of surface-modified formulas in experimental food matrices. However, before the viability and the applications of nutrients in liposomal form in the edible field can be determined, the digestion behavior along the human gastrointestinal tract (GIT) must be clarified. In vitro digestion models, from static models to dynamic mono-/bi-/multi-compartmental models, are increasingly being developed and applied as alternatives to in vivo assays. This review describes the surface interactions of liposomes with their encapsulated ingredients and with external food components and updates the biological fate of liposomes after ingestion. It summarizes current models for the human stomach and intestine that are available and their relevance in nutritional studies. It highlights limitations and challenges in the use of these models for liposomal colloid system digestion and discusses crucial factors, such as enzymes and bile salts, that affect liposomal bilayer degradation.

Improvement of dermal delivery of tetracycline using vesicular nanostructures

The objective of this investigation was to study the potential use of nanoliposomes and nanotransfersomes in dermal delivery of tetracycline hydrochloride (TC) for acne treatment. Vesicular nanostructures were prepared by thin film hydration method and evaluated for their size, zeta potential, morphology, and entrapment efficiency. Minimal inhibitory concentration values of TC-loaded vesicles were evaluated and compared with TC aqueous solution against Staphylococcus epidermis. In vitro drug release and ex vivo drug permeation through the excised rat skin were performed to assess drug delivery efficiency. Particle size, zeta potential, and entrapment efficiency of prepared nanoliposomes and nanotransfersomes were found to be 75 and 78 nm, 17 and 7 mV, and 45 and 55%, respectively. Antimicrobial analysis indicated that there was no difference between vesicular formulations and aqueous solution of TC. In vitro drug release study indicated that nanoliposomes could release TC 2.6 folds more than nanotransfersomes, and skin permeation study showed that the permeability of TC-loaded nanotransfersomes was 1.6 times higher than nanoliposomes which was also confirmed by fluorescence microscope imaging. These findings concluded that nanoliposomal and especially nanotransfersomal formulations could be proposed as the potential approach for better therapeutic performance of TC against acne.

Suppression of Bone Resorption by miR-141 in Aged Rhesus Monkeys

Aging-related osteoporosis (OP) is considered a serious public health concern. Approximately 30% of postmenopausal women suffer from OP; more than 40% of them risk fragility fractures. Multiple drugs have been prescribed to treat OP, but they are not ideal because of low cure rates and adverse side effects. miRNA-based gene therapy is a rapidly developing strategy in disease treatment that presents certain advantages, such as large-scale production capability, genetic safety, and rapid effects. miRNA drugs have been used primarily in cancer treatments; they have not yet been reported as candidates for osteoclast-targeted-OP treatment in primates. Their therapeutic efficacy has been limited by several shortcomings, such as low efficiency of selective delivery, insufficient expression levels in targeting cells, and unexpected side effects. Here, we identify miR-141 as a critical suppressor of osteoclastogenesis and bone resorption. The expression levels of miR-141 are positively correlated with BMD and negatively correlated with the aging of bones in both aged rhesus monkeys (Macaca mulatta) and osteoporotic patients. Selective delivery of miR-141 into the osteoclasts of aged rhesus monkeys via a nucleic acid delivery system allowed for a gradual increase in bone mass without significant effects on the health and function of primary organs. Furthermore, we found that the functional mechanism of miR-141 resides in its targeting of two osteoclast differentiation players, Calcr (calcitonin receptors) and EphA2 (ephrin type-A receptor 2 precursor). Our study suggests that miRNAs, such as miR-141, could play a crucial role in suppressing bone resorption in primates and provide reliable experimental evidence for the clinical application of miRNA in OP treatment. © 2018 American Society for Bone and Mineral Research.

Liposomally formulated phospholipid-conjugated novel near-infrared fluorescence probe for particle size effect on cellular uptake and biodistribution in vivo

Lipid based nanoparticles (LBNs) with excellent biocompatibility and versatility have received much attention from the drug delivery community recently. A detailed understanding of in vitro and vivo fate of LBNs is important for developing different types of LBNs with improved selectivity and low cytotoxicity. We developed a novel near-infrared (NIR) probe with high fluorescence, designated as DSPE-ir623 (iDSPE). Then, we prepared iDSPE-embeded liposomes (iLPs) with two different hydrodynamic sizes (∼100nm and ∼400nm) to evaluate the effect of particle size on cellular uptake and biodistribution of nanoliposomes in vivo. These iLPs were proved to exhibit good monodispersity, excellent fluorescence and stability. In vitro cell uptake tests demonstrated that iLPs-1 (∼100nm) were taken up more by HT-29 cells than iLPs-2 (∼400nm). Notably, the fluorescence of iLPs can be employed for real-time monitoring of the subcellular locating and its metabolic distribution in vivo. Near-infrared imaging in vivo illustrated that iLPs-1 was mainly accumulated in the tumor tissues, while iLPs-2 was accumulated in liver and spleen. The results indicated that the size of iLPs play an important role in the regulation of intracellular trafficking and biodistribution of liposomes, which also provide a new insight into the development of more effective LBNs. Hence, iDSPE might be a promising tool for the reliable tracing of different types of LBNs.

Liposomally formulated phospholipid-conjugated novel near-infrared fluorescence probe for particle size effect on cellular uptake and biodistribution in vivo

Lipid based nanoparticles (LBNs) with excellent biocompatibility and versatility have received much attention from the drug delivery community recently. A detailed understanding of in vitro and vivo fate of LBNs is important for developing different types of LBNs with improved selectivity and low cytotoxicity. We developed a novel near-infrared (NIR) probe with high fluorescence, designated as DSPE-ir623 (iDSPE). Then, we prepared iDSPE-embeded liposomes (iLPs) with two different hydrodynamic sizes (∼100nm and ∼400nm) to evaluate the effect of particle size on cellular uptake and biodistribution of nanoliposomes in vivo. These iLPs were proved to exhibit good monodispersity, excellent fluorescence and stability. In vitro cell uptake tests demonstrated that iLPs-1 (∼100nm) were taken up more by HT-29 cells than iLPs-2 (∼400nm). Notably, the fluorescence of iLPs can be employed for real-time monitoring of the subcellular locating and its metabolic distribution in vivo. Near-infrared imaging in vivo illustrated that iLPs-1 was mainly accumulated in the tumor tissues, while iLPs-2 was accumulated in liver and spleen. The results indicated that the size of iLPs play an important role in the regulation of intracellular trafficking and biodistribution of liposomes, which also provide a new insight into the development of more effective LBNs. Hence, iDSPE might be a promising tool for the reliable tracing of different types of LBNs.

Towards topical microRNA-directed therapy for epidermal disorders

There remains an unmet dermatological need for innovative topical agents that achieve better longterm outcomes with fewer side effects. Modulation of the expression and activity of microRNA (miRNAs) represents an emerging translational framework for the development of such innovative therapies because changes in the expression of one miRNA can have wide-ranging effects on diverse cellular processes associated with disease. In this short review, the roles of miRNA in epidermal development, psoriasis, cutaneous squamous cell carcinoma and re-epithelisation are highlighted. Consideration is given to the delivery of oligonucleotides that mimic or inhibit miRNA function using vehicles such as cell penetrating peptides, spherical nucleic acids, deformable liposomes and liquid crystalline nanodispersions. Formulation of miRNA-directed oligonucleotides with such skin-penetrating epidermal agents will drive the development of RNA-based cutaneous therapeutics for deployment as primary or adjuvant therapies for epidermal disorders.