Self-assembly mucoadhesive beads of κ-carrageenan/sericin for indomethacin oral extended release.

Oral drug administration, especially when composed of mucoadhesive delivery systems, has been a research trend due to increased residence time and contact with the mucosa, potentially increasing drug bioavailability and stability. In this context, this study aimed to develop self-assembly mucoadhesive beads composed of blends of κ-carrageenan and sericin (κ-Car/Ser) loaded with the anti-inflammatory drug indomethacin (IND). We investigated the swelling, adhesion behaviour, and mechanical/physical properties of the beads, assessing their effects on cell viability, safety and permeation characteristics in both 2D and triple-culture model. The swelling ratio of the beads indicated pH-responsiveness, with maximum water absorption at pH 6.8, and strong mucoadhesion, increasing primarily with higher polymer concentrations. The beads exhibited thermal stability and no chemical interaction with IND, showing improved mechanical properties. Furthermore, the beads remained stable during accelerated and long-term storage studies. The beads were found to be biocompatible, and IND encapsulation improved cell viability (>70 % in both models, 79 % in VN) and modified IND permeation through the models (6.3 % for F5 formulation (κ-Car 0.90 % w/v | Ser 1.2 % w/v| IND 3.0 g); 10.9 % for free IND, p < 0.05). Accordingly, κ-Car/Ser/IND beads were demonstrated to be a promising IND drug carrier to improve oral administration while mitigating the side effects of non-steroidal anti-inflammatories.

Bridging the gap between testing and clinics exploring alternative pre-clinical models in melanoma research.

Melanoma, the deadliest form of skin cancer, poses a significant clinical challenge for the development of effective treatments. Conventional in vivo animal studies have shown limited translational relevance to humans, raising strength to pre-clinical models for melanoma research. This review provides an in-depth analysis of alternative pre-clinical models including in vitro and ex vivo platforms such as reconstructed skin, spheroids, organoids, organotypic models, skin-on-a-chip, and bioprinting. Through a comprehensive analysis, the specific attributes, advantages, and limitations of each model are elucidated. It discusses the points related to the uniqueness advantages, from capturing complex interactions between melanoma cells and their microenvironment to enabling high-throughput drug screening and personalized medicine approaches. This review is structured covering firstly the roadmap to identify the co-occurrence of discovering new melanoma treatments and the development of its models, secondly it covers a comparative between the most used models followed by a section discussing each of them: the in vitro and ex vivo models. It intends to serve as an asset for researchers of melanoma field and clinicians involved in melanoma therapy, offering insights into the diverse preclinical models available for optimizing their integration into the translational pipeline.

Trends in 3D models of inflammatory bowel disease.

Inflammatory bowel disease (IBD) encompasses a set of chronic inflammatory conditions, namely Crohn's disease and ulcerative colitis. Despite all advances in the management of IBD, a definitive cure is not available, largely due to a lack of a holistic understanding of its etiology and pathophysiology. Several in vitro, in vivo, and ex vivo models have been developed over the past few decades in order to abbreviate remaining gaps. The establishment of reliable and predictable in vitro intestinal inflammation models may indeed provide valuable tools to expedite and validate the development of therapies for IBD. Three-dimensional (3D) models provide a more accurate representation of the different layers of the intestine, contributing to a stronger impact on drug screening and research on intestinal inflammation, and bridging the gap between in vitro and in vivo research. This work provides a critical overview on the state-of-the-art on existing 3D models of intestinal inflammation and discusses the remaining challenges, providing insights on possible pathways towards achieving IBD mimetic models. We also address some of the main challenges faced by implementing cell culture models in IBD research while bearing in mind clinical translational aspects.

Poly-ε-caprolactone based nanoparticles for delivery of genistein in melanoma treatment

Abstract We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studies.

Characterization of a human lesioned-skin model to assess the influence of skin integrity on drug permeability.

The stratum corneum (SC) is the skin's outermost layer, organized by clusters of corneocytes among a lipid matrix, acting as a barrier. This "brick and mortar" organization is modified in many skin diseases. We proposed a lesioned-skin model for assessing the permeability of topical formulations and the impact of skin integrity on the permeability of molecules. We anticipate that removal of the SC compromises the skin barrier function, making it more permeable, affecting the biopharmaceutics of topical formulations. By stripping with 25 strips (Corneofix®), the thickness of the SC was considerably reduced, exposing the viable epidermis. Transversal and upper views of the skin by electronic microscopy and histology confirm the removal of the SC. After, we evaluated the permeability of tacrolimus (Protopic®, 0.1 % and 0.03 %) by HPLC-UV. The non-lesioned skin presented 20-25 % of tacrolimus in the SC and no drug permeated through the skin's inner layers. Contrary, the lesioned-skin model allowed the permeation of tacrolimus to the epidermis, dermis, and also in the receptor medium. These results highlight the importance of using diseased skin tissue as opposed to normal skin when assessing the permeability of pharmaceutical formulations for local topical delivery, closely mimicking the occurred events in clinical scenario.

Hybrid Magnetic Lipid-Based Nanoparticles for Cancer Therapy.

Cancer is one of the major public health problems worldwide. Despite the advances in cancer therapy, it remains a challenge due to the low specificity of treatment and the development of multidrug resistance mechanisms. To overcome these drawbacks, several drug delivery nanosystems have been investigated, among them, magnetic nanoparticles (MNP), especially superparamagnetic iron oxide nanoparticles (SPION), which have been applied for treating cancer. MNPs have the ability to be guided to the tumor microenvironment through an external applied magnetic field. Furthermore, in the presence of an alternating magnetic field (AMF) this nanocarrier can transform electromagnetic energy in heat (above 42 °C) through Néel and Brown relaxation, which makes it applicable for hyperthermia treatment. However, the low chemical and physical stability of MNPs makes their coating necessary. Thus, lipid-based nanoparticles, especially liposomes, have been used to encapsulate MNPs to improve their stability and enable their use as a cancer treatment. This review addresses the main features that make MNPs applicable for treating cancer and the most recent research in the nanomedicine field using hybrid magnetic lipid-based nanoparticles for this purpose.

New Technological Approaches for Dental Caries Treatment: From Liquid Crystalline Systems to Nanocarriers.

Dental caries is the most common oral disease, with high prevalence rates in adolescents and low-income and lower-middle-income countries. This disease originates from acid production by bacteria, leading to demineralization of the dental enamel and the formation of cavities. The treatment of caries remains a global challenge and the development of effective drug delivery systems is a potential strategy. In this context, different drug delivery systems have been investigated to remove oral biofilms and remineralize dental enamel. For a successful application of these systems, it is necessary that they remain adhered to the surfaces of the teeth to allow enough time for the removal of biofilms and enamel remineralization, thus, the use of mucoadhesive systems is highly encouraged. Among the systems used for this purpose, liquid crystalline systems, polymer-based nanoparticles, lipid-based nanoparticles, and inorganic nanoparticles have demonstrated great potential for preventing and treating dental caries through their own antimicrobial and remineralization properties or through delivering drugs. Therefore, the present review addresses the main drug delivery systems investigated in the treatment and prevention of dental caries.

Docetaxel-loaded folate-modified TPGS-transfersomes for glioblastoma multiforme treatment.

Glioblastoma multiforme (GBM) is a first primary Central Nervous System tumor with high incidence and lethality. Its treatment is hampered by the difficulty to overcome the blood-brain barrier (BBB) and by the non-specificity of chemotherapeutics to tumor cells. This study was based on the development characterization and in vitro efficacy of folate-modified TPGS transfersomes containing docetaxel (TF-DTX-FA) to improve GBM treatment. TF-DTX-FA and unmodified transfersomes (TF-DTX) were prepared through thin-film hydration followed by extrusion technique and characterized by physicochemical and in vitro studies. All formulations showed low particles sizes (below 200 nm), polydispersity index below 0.2, negative zeta potential (between -16.75 to -12.45 mV) and high encapsulation efficiency (78.72 ± 1.29% and 75.62 ± 0.05% for TF-DTX and TF-DTX-FA, respectively). Furthermore, cytotoxicity assay of TF-DTX-FA showed the high capacity of the nanocarriers to reduce the viability of U-87 MG in both 2D and 3D culture models, when compared with DTX commercial formulation and TF-DTX. In vitro cellular uptake assay indicated the selectivity of transfersomes to tumoral cells when compared to normal cells, and the higher ability of TF-DTX-FA to be internalized into 2D U-87 MG in comparison with TF-DTX (72.10 and 62.90%, respectively, after 24 h). Moreover, TF-DTX-FA showed higher permeability into 3D U-87 MG spheroid than TF-DTX, suggesting the potential FA modulation to target treatment of GBM.

Design of experiments (DoE) to develop and to optimize nanoparticles as drug delivery systems.

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.

Ex vivo model of human skin (hOSEC) for assessing the dermatokinetics of the anti-melanoma drug Dacarbazine.

Alternative models to replace animals in experimental studies remain a challenge in testing the effectiveness of dermatologic and cosmetic drugs. We proposed a model of human organotypic skin explant culture (hOSEC) to assess the profile of cutaneous drug skin distribution, adopting dacarbazine as a model, and respective new methodologies for dermatokinetic analysis. The viability tests were evaluated in primary keratinocytes and fibroblasts, and skin by MTT and TTC assays, respectively. Then, dacarbazine was applied to the culture medium, and the hOSEC method was applied to verify the dynamics of skin distribution of dacarbazine and determine its dermatokinetic profile. The results of cell and tissue viability showed that both were considered viable. The dermatokinetic results indicated that dacarbazine can be absorbed through the skin, reaching a concentration of 36.36 µg/mL (18,18%) of the initial dose (200 µg/mL) after 12 h in culture. Histological data showed that the skin maintained its structure throughout the tested time that the hOSEC method was applied. No apoptotic cells were observed in the epidermal and dermal layers. No visible changes in the dermo-epidermal junction and no inflammatory processes with the recruitment of defense cells were observed. Hence, these findings suggest that the hOSEC concept as an alternative ex vivo model for assessing the dynamics of skin distribution of drugs, such as dacarbazine, and determining their respective dermatokinetic profiles.

Advances in lyotropic liquid crystal systems for skin drug delivery.

INTRODUCTION: Lyotropic liquid crystals (LLCs) are organized mesophases with intermediate properties between liquids and solids. The LLC and its liquid crystalline nanoparticles (LCNPs) have attracted great interest from the scientific community in recent years as potential drug delivery systems due to the high internal ordering and symmetry with a wide interfacial area. AREAS COVERED: This article aims to gather information and to provide a description of the highly organized structures of LLCs. Updates on production methods and new insights for LCNPs optimization and physico-chemical and morphological caracterization techniques were discussed. We also discussed why these systems proved to be a platform for the design of nanocarrier drug delivery, with an emphasis on topical and transdermal applications. EXPERT OPINION: Drug delivery platforms are of particular importance to improve the biopharmaceutical aspects of therapies topically. Although several systems can be used, LLC or LCNPs appear to be favored due to their similarity to the lipid structure of the skin. The highly ordered structure and the possibility of chemical modifications make it possible to obtain better clinical responses. The results of several studies support the innovations in this field and predict that these systems can innovate the market of technologies for the treatment of cutaneous diseases and cosmetology.

Therapeutic applications and delivery systems for triptolide.

Triptolide (TPL) is a natural compound and active component of Tripterygium wilfordii Hook F., an Asian native woody vine widely used for over 200 years in Chinese medicine. Hot water, ethanol-ethyl acetate, and chloroform-methanol extracts are the first reported TPL preparations in the literature, and since then, several studies for application in inflammation processes and cancer are described due to the antitumor, anti-inflammatory, and immunosuppressive characteristics of the molecule. However, physicochemical properties such as poor solubility and bioavailability are the main concerns regarding the TPL safety and efficacy in clinical studies since trials have reported adverse side effects alongside the excellent TPL therapeutic effects. Here, we review the main TPL applications and issues related to the drug usage, and a comprehensive summary of diseases is provided. Special emphasis is given to drug delivery systems designed to overcome the TPL physicochemical characteristics such as poor drug solubility, and how to increase efficacy and obtain a safe drug profile. Graphical abstract.

Microemulsion co-delivering vitamin A and vitamin E as a new platform for topical treatment of acute skin inflammation.

In this study, we developed a water-in-oil microemulsion containing vitamin A (retinol) and vitamin E (α-tocopherol), which serves as a multifunctional nanosystem that co-delivers antioxidants and displayed additive effect against acute skin inflammation. Microemulsion (ME) was prepared by mixing a surfactant blend (Tween 80 and propylene glycol, 5:1) with isopropyl myristate and water (ratio of 50:40:10, respectively). Vitamin A (0.05% w/w concentration) and/or vitamin E (0.1% w/w concentration) were incorporated into the surfactant mixture of ME by stirring with a magnetic stirrer for 30 min. This multifunctional ME displayed physical stability, with low cytotoxicity in 3T3 cell line, as well as cellular internalization into the cytosol. In vivo treatments using ME delivering α-tocopherol reduced dermal expression of TNF-α by 1.3-fold (p < 0.01), when compared to unloaded ME treatment group. When retinol was added into the ME containing α-tocopherol, it further reduced TNF-α expression by 2-fold (p < 0.001), suggesting the additive effect of vitamin E and vitamin A in the treatment against skin inflammation. In conclusion, we successfully developed the use of water-in-oil ME to pack both vitamin E and vitamin A, and demonstrated for the first time its anti-inflammatory potential when applied topically to TPA-induced inflamed skin.

Nanotechnology approaches in the current therapy of skin cancer.

Skin cancer is a high burden disease with a high impact on global health. Conventional therapies have several drawbacks; thus, the development of effective therapies is required. In this context, nanotechnology approaches are an attractive strategy for cancer therapy because they enable the efficient delivery of drugs and other bioactive molecules to target tissues with low toxic effects. In this review, nanotechnological tools for skin cancer will be summarized and discussed. First, pathology and conventional therapies will be presented, followed by the challenges of skin cancer therapy. Then, the main features of developing efficient nanosystems will be discussed, and next, the most commonly used nanoparticles (NPs) described in the literature for skin cancer therapy will be presented. Subsequently, the use of NPs to deliver chemotherapeutics, immune and vaccine molecules and nucleic acids will be reviewed and discussed as will the combination of physical methods and NPs. Finally, multifunctional delivery systems to codeliver anticancer therapeutic agents containing or not surface functionalization will be summarized.

Nanostructured lipid carrier co-delivering tacrolimus and TNF-α siRNA as an innovate approach to psoriasis.

Since psoriasis is an immuno-mediated skin disease, long-term therapies are necessary for its treatment. In clinical investigations, tacrolimus (TAC), a macrolide immunosuppressive inhibitor of calcineurin, arises as an alternative for the treatment of psoriasis, acting in some cytokines involved in the pathogenesis of the disease. Here, we aim to study the psoriasis treatment with TAC and siRNA for one of most cytokines expressed in psoriasis, the TNF-α. A multifunctional nanostructure lipid carrier (NLC) was developed to co-delivery TAC and siRNA. Results showed that the particle size and zeta potential were around 230 nm and + 10 mV, respectively. The release study demonstrated a controlled release of TAC, and the permeation and retention profile in the skin tissue show to be promising for topical application. The cell viability and uptake in murine fibroblast presented low toxicity associated to uptake of NLC in 4 h, and finally, the in vivo animal model demonstrates the efficiency of the NLC multifunctional, exhibiting a reduction of the cytokine TNF-α expression about 7-fold and presenting a synergic effect between the TAC and TNF-α siRNA. The developed system was successfully to treat in vivo psoriatic animal model induced by imiquimod and the synergic combination was reported here for the first time. Graphical abstract.

Nanostructured Systems Improve the Antimicrobial Potential of the Essential Oil from Cymbopogon densiflorus Leaves.

The physicochemical characteristics of nanostructured suspensions are important prerequisites for the success of new drug development. This work aimed to develop nanometric systems containing Cymbopogon densiflorus leaf essential oil and to evaluate their antimicrobial activity. The essential oil was isolated by hydrodistillation from leaves and analyzed by GC-MS. The main constituents were found to be trans-p-mentha-2,8-dien-1-ol, cis-p-mentha-2,8-dien-1-ol, trans-p-mentha-1(7),8-dien-2-ol, cis-piperitol, and cis-p-mentha-1(7),8-dien-2-ol. In silico prediction analysis suggested that this oil possesses antimicrobial potential and the main mechanism of action might be the peptidoglycan glycosyltransferase inhibition. Nanoemulsions were prepared by the phase inversion method, and liposomes were made by the film hydration method. Qualitative evaluation of the antimicrobial activity was performed by the diffusion disk assay with 24 microorganisms; all of them were found to be sensitive to the essential oil. Subsequently, this property was quantified by the serial microdilution technique, where the nanoformulations demonstrated improved activity in comparison with the free oil. Bactericidal action was tested by the propidium iodide method, which revealed that free essential oil and nanoemulsion increased cytoplasmic membrane permeability, while no difference was observed between negative control and liposome. These results were confirmed by images obtained using transmission electron microscopy. This study has shown an optimization in the antimicrobial activity of C. densiflorus essential oil by a nanoemulsion and a liposomal formulation of the active substances.