Development of Glycyrrhizinic Acid-Based Lipid Nanoparticle (LNP-GA) as An Adjuvant That Improves the Immune Response to Porcine Epidemic Diarrhea Virus Spike Recombinant Protein.

Porcine epidemic diarrhea virus (PEDV) has affected the pork industry worldwide and during outbreaks the mortality of piglets has reached 100%. Lipid nanocarriers are commonly used in the development of immunostimulatory particles due to their biocompatibility and slow-release delivery properties. In this study, we developed a lipid nanoparticle (LNP) complex based on glycyrrhizinic acid (GA) and tested its efficacy as an adjuvant in mice immunized with the recombinant N-terminal domain (NTD) of porcine epidemic diarrhea virus (PEDV) spike (S) protein (rNTD-S). The dispersion stability analysis (Z-potential -27.6 mV) confirmed the size and charge stability of the LNP-GA, demonstrating that the particles were homogeneously dispersed and strongly anionic, which favors nanoparticles binding with the rNTD-S protein, which showed a slightly positive charge (2.11 mV) by in silico analysis. TEM image of LNP-GA revealed nanostructures with a spherical-bilayer lipid vesicle (~100 nm). The immunogenicity of the LNP-GA-rNTD-S complex induced an efficient humoral response 14 days after the first immunization (p < 0.05) as well as an influence on the cellular immune response by decreasing serum TNF-α and IL-1ß concentrations, which was associated with an anti-inflammatory effect.

Ionizable Lipid Nanoparticle-Mediated TRAIL mRNA Delivery in the Tumor Microenvironment to Inhibit Colon Cancer Progression.

Introduction: Immunotherapy has revolutionized cancer treatment by harnessing the immune system to enhance antitumor responses while minimizing off-target effects. Among the promising cancer-specific therapies, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has attracted significant attention. Methods: Here, we developed an ionizable lipid nanoparticle (LNP) platform to deliver TRAIL mRNA (LNP-TRAIL) directly to the tumor microenvironment (TME) to induce tumor cell death. Our LNP-TRAIL was formulated via microfluidic mixing and the induction of tumor cell death was assessed in vitro. Next, we investigated the ability of LNP-TRAIL to inhibit colon cancer progression in vivo in combination with a TME normalization approach using Losartan (Los) or angiotensin 1-7 (Ang(1-7)) to reduce vascular compression and deposition of extracellular matrix in mice. Results: Our results demonstrated that LNP-TRAIL induced tumor cell death in vitro and effectively inhibited colon cancer progression in vivo, particularly when combined with TME normalization induced by treatment Los or Ang(1-7). In addition, potent tumor cell death as well as enhanced apoptosis and necrosis was found in the tumor tissue of a group treated with LNP-TRAIL combined with TME normalization. Discussion: Together, our data demonstrate the potential of the LNP to deliver TRAIL mRNA to the TME and to induce tumor cell death, especially when combined with TME normalization. Therefore, these findings provide important insights for the development of novel therapeutic strategies for the immunotherapy of solid tumors.

siRNA lipid nanoparticles for CXCL12 silencing modulate brain immune response during Zika infection.

CXCL12 is a key chemokine implicated in neuroinflammation, particularly during Zika virus (ZIKV) infection. Specifically, CXCL12 is upregulated in circulating cells of ZIKV infected patients. Here, we developed a lipid nanoparticle (LNP) to deliver siRNA in vivo to assess the impact of CXCL12 silencing in the context of ZIKV infection. The biodistribution of the LNP was assessed in vivo after intravenous injection using fluorescently tagged siRNA. Next, we investigated the ability of the developed LNP to silence CXCL12 in vivo and assessed the resulting effects in a murine model of ZIKV infection. The LNP encapsulating siRNA significantly inhibited CXCL12 levels in the spleen and induced microglial activation in the brain during ZIKV infection. This activation was evidenced by the enhanced expression of iNOS, TNF-α, and CD206 within microglial cells. Moreover, T cell subsets exhibited reduced secretion of IFN-É£ and IL-17 following LNP treatment. Despite no observable alteration in viral load, CXCL12 silencing led to a significant reduction in type-I interferon production compared to both ZIKV-infected and uninfected groups. Furthermore, we found grip strength deficits in the group treated with siRNA-LNP compared to the other groups. Our data suggest a correlation between the upregulated pro-inflammatory cytokines and the observed decrease in strength. Collectively, our results provide evidence that CXCL12 silencing exerts a regulatory influence on the immune response in the brain during ZIKV infection. In addition, the modulation of T-cell activation following CXCL12 silencing provides valuable insights into potential protective mechanisms against ZIKV, offering novel perspectives for combating this infection.

In Vitro Evaluation of NLS-DTX Activity in Triple-Negative Breast Cancer.

Cancer is one of the most lethal diseases in the world, and the development and improvement of treatments used in cancer therapies are extremely important for a better quality of life for patients. In view of the current problems in drug administration such as low solubility and adverse effects, the activity of a solid lipid nanoparticle containing docetaxel (SLN-DTX), a drug already used in conventional therapies, was evaluated in a cell line (MDA-MB-231) of one of the most aggressive types of breast cancer with the worst prognosis, triple-negative breast cancer. Viability tests indicated that SLN-DTX has a greater dependence on the treatment dose when compared to the free drug, which indicates a more controlled release of the drug, and both reduced viability by around 50% at a concentration of 1 µg/mL after 72 h. Transmission electron microscopy (TEM) and confocal and light microscopy analyses indicated that after treatment the cells enter a mitotic catastrophe, characteristic of antimitotic drugs that usually make cells progress to death or senescence. Cells treated with both DTX and SLN-DTX showed significant inhibition of mobility, 73.6% and 66.5% when treated with SLN-DTX and DTX, respectively, compared to the 11.4% of the control after 72 h, characteristics that are very relevant in tumor development and progression. SLN-DTX demonstrated its great potential as a nanocarrier by maintaining and improving the drug's action in the MDA-MB-231 cell line.

Treatment With Methotrexate Associated With Lipid Core Nanoparticles Prevents Aortic Dilation in a Murine Model of Marfan Syndrome.

In Marfan syndrome (MFS), dilation, dissection, and rupture of the aorta occur. Inflammation can be involved in the pathogenicity of aortic defects and can thus be a therapeutic target for MFS. Previously, we showed that the formulation of methotrexate (MTX) associated with lipid nanoparticles (LDE) has potent anti-inflammatory effects without toxicity. To investigate whether LDEMTX treatment can prevent the development of aortic lesions in the MFS murine model. MgΔloxPneo MFS (n = 40) and wild-type (WT, n = 60) mice were allocated to 6 groups weekly injected with IP solutions of: (1) only LDE; (2) commercial MTX; (3) LDEMTX (dose = 1mg/kg) between 3rd and 6th months of life. After 12 weeks of treatments, animals were examined by echocardiography and euthanatized for morphometric and molecular studies. MFS mice treated with LDEMTX showed narrower lumens in the aortic arch, as well as in the ascending and descending aorta. LDEMTX reduced fibrosis and the number of dissections in MFS but not the number of elastic fiber disruptions. In MFS mice, LDEMTX treatment lowered protein expression of pro-inflammatory factors macrophages (CD68), T-lymphocytes (CD3), tumor necrosis factor-α (TNF-α), apoptotic factor cleaved-caspase 3, and type 1 collagen and lowered the protein expression of the transforming growth factor-ß (TGF-ß), extracellular signal-regulated kinases ½ (ERK1/2), and SMAD3. Protein expression of CD68 and CD3 had a positive correlation with an area of aortic lumen (r 2 = 0.36; p < 0.001), suggesting the importance of inflammation in the causative mechanisms of aortic dilation. Enhanced adenosine availability by LDEMTX was suggested by higher aortic expression of an anti-adenosine A2a receptor (A2a) and lower adenosine deaminase expression. Commercial MTX had negligible effects. LDEMTX prevented the development of MFS-associated aortic defects and can thus be a candidate for testing in clinical studies.

Assessment of a Novel Vitamin D3 Formulation with Nanostructured Lipid Carriers for Transdermal Delivery.

OBJECTIVE: Develop and assess a transdermal emulsion loaded with nanostructured lipid carriers for vitamin D3 supplementation. METHODS: Vitamin D3 loaded nanostructured lipid carriers, produced via high shear homogenization and ultrasonication, were assessed for their particle size, distribution, morphology, zeta potential, entrapment efficiency, and cytotoxicity. They were incorporated into a transdermal vehicle, and the stability and ex vivo permeation were evaluated. RESULTS: Spherical nanoparticles were developed with a particle size of 192.5 nm, a polydispersity index of 0.13, a zeta potential of -29.0 mV, and an entrapment efficiency of 99.75%. They were stable (particle size and distribution) for 15 days when stored in a refrigerator, and for 30 days at room temperature and 32°C. The nanoparticles decreased the drug cytotoxicity against fibroblasts, as shown by IC50 (nanoparticle: 32.48 µg mL-1 vitamin D3: 16.73 µg mL-1). The emulsion loaded with nanoparticles minimized the degradation of vitamin D3 when compared with the nanoparticle dispersion. Additionally, the emulsion provided the skin permeation of vitamin D3 following the recommended daily allowance. CONCLUSION: To the best of our knowledge, this is the first study to use nanostructured lipid carriers for transdermal delivery of vitamin D. The developed formulation is a promising strategy to overcome the vitamin D3 variable oral bioavailability. It also represents a comfortable route of administration; thus it could be beneficial for patients and clinicians. However, further studies are needed to allow the permeation of larger amounts of vitamin D3, and the combination of these nanoparticles with microneedles would be interesting.

Avaliação do tratamento quimioterápico paliativo com o esquema LDE- paclitaxel em pacientes portadores de metástases ósseas por neoplasia maligna / Evaluation of palliative chemotherapy treatment with the LDEpaclitaxel regimen in patients with bone metastases from malignant neoplas

Introdução: Pacientes com câncer em estádios avançados e metástases ósseas frequentemente não apresentam condições clínicas para a realização de esquemas quimioterápicos convencionais subsequentes, restringindo as opções de tratamento. Anteriormente, demonstramos que nanopartículas artificiais lipídicas (LDE), semelhantes à lipoproteína de baixa densidade (LDL) rica em colesterol, são captadas por tecidos malignos, e quando associadas aos quimioterápicos, após injeção pela via endovenosa, reduz drasticamente a toxicidade do tratamento. Os objetivos deste presente estudo foram avaliar a resposta clínica ao tratamento quimioterápico com paclitaxel (PTX) associado à LDE; avaliar as toxicidades clínicas e laboratorial, e a capacidade da associação LDE-PTX em reduzir a dor oncológica relacionada às metástases ósseas em pacientes com carcinoma de mama, próstata e pulmão, previamente tratados e não elegíveis para tratamento quimioterápico convencional subsequente. Métodos: Dezoito pacientes (8 com câncer de mama, 5 de próstata e 5 de pulmão) com metástases ósseas foram incluídos. O tratamento consistiu no esquema LDE-PTX na dose convencional do PTX (175 mg/m2 de superfície corpórea de 3/3 semanas) e os pacientes foram avaliados por resposta clínica, redução da dor óssea, uso de medicamentos opióides, e ocorrência de fraturas ósseas patológicas. Resultados: No total, 104 ciclos de quimioterapia foram realizados, e nenhum paciente apresentou toxicidade clínica, laboratorial, assim como não houve fraturas patológicas. Dos 18 pacientes incluídos, 9 tiveram sobrevida livre de progressão de doença 6 meses. Houve em todos os pacientes redução da dor óssea, permitindo substituição da medicação opióide por analgésico não opióide. Conclusão: A melhora significativa na dor óssea sem que tenha ocorrido toxicidade do tratamento, e o tempo de não progressão de doença 6 meses na metade dos pacientes sugere que esses pacientes tenham se beneficiado consistentemente do tratamento com a LDE-PTX. Portanto, a LDE-PTX pode tornar- se uma opção terapêutica interessante em pacientes com carcinomas de próstata, mama ou pulmão em estágios avançados e sem condições clínicas de se submeterem a outros esquemas quimioterápicos convencionais

Introduction: Patients with advanced cancer and bone metastases usually do not have clinical conditions to perform additional conventional chemotherapy regimens, restricting treatment options. Previously, we showed that lipid core nanoparticles (LDE), similar to cholesterol-rich low-density lipoprotein (LDL), are taken up by malignant tissues, and when associated to chemotherapy, after endovenous injection, it drastically decreases the toxicity of the treatment. The objectives of this study were to evaluate the clinical response to chemotherapy treatment with paclitaxel (PTX) associated with LDE; to evaluate the clinical and laboratorial toxicities, and the ability of the LDE-PTX to reduce cancer pain related to bone metastases in patients with breast, prostate or lung carcinoma, previously treated and not eligible for subsequent conventional chemotherapy treatment. Methods: Eighteen patients (8 with breast cancer, 5 with prostate and 5 with lung) with bone metastases were included. Treatment consisted of the LDE-PTX regimen at a conventional dose of PTX (175 mg/m2 body surface area, 3/3 weeks) and patients were evaluated for clinical response, reduction in bone pain, use of opioid medications, and the occurrence of pathological bone fractures. Results: In total, 104 chemotherapy cycles were performed, and none of the patients showed clinical or laboratorial toxicities, as well as there were no pathological fractures. Of the 18 patients evaluated, 9 had progression-fee survival 6 months. Patients had decrease in bone pain allowing replacement of opioid medication by another non-opioid analgesic. Conclusion: Significant improvement in bone pain without treatment toxicity, and time to disease progression of 6 months in half of the patients suggest that these patients have consistently benefited with LDE-PTX treatment. Therefore, LDE-PTX may become an interesting therapeutic option in patients with advanced stage of prostate, breast or lung carcinomas and without clinical conditions to undergo other conventional chemotherapy regimens

Development of a Nanostructured Lipid Carrier (NLC) by a Low-Energy Method, Comparison of Release Kinetics and Molecular Dynamics Simulation.

Lipid nanocarriers have a great potential for improving the physicochemical characteristics and behavior of poorly water-soluble drugs, such as aqueous dispersibility and oral bioavailability. This investigation presents a novel nanostructured lipid carrier (NLC) based on a mixture of solid lipid glycerides, fatty acid esters of PEG 1500 (Gelucire® 44/14), and an oil mix composed of capric and caprylic triglycerides (Miglyol® 812). These NLCs were developed by a simple low-energy method based on melt emulsification to yield highly encapsulating and narrowly distributed nanoparticles (~100 nm, PdI = 0.1, and zeta potential = ~-10 mV). Rhodamine 123 was selected as a poorly water-soluble drug model and owing to its spectroscopic properties. The novel NLCs were characterized by dynamic light scattering (DLS), zeta potential, nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and colloidal stability. The drug release was determined through a dialysis bag and vertical Franzs' cells to provide insights about the methods' suitability, revealing similar performance regardless of their different fluid dynamics. Rhodamine 123 followed a characteristic biphasic release profile owing to the swelling of the hydrophilic polymer coating and diffusion process from the lipid core as revealed by the Korsmeyers-Peppas kinetic modeling. Moreover, to elucidate the formation and incorporation of Rhodamine 123 into the NLC core, several molecular dynamics simulations were conducted. The temperature was shown to be an important condition to improve the formation of the nanoparticles. In addition, the liquid lipid incorporation to the formulation forms nanoparticles with imperfect centers, in contrast to nanoparticles without it. Moreover, Miglyol® 812 improves hydrophobic molecule solubility. These results suggest the potential of novel NLC as a drug delivery system for poorly water-soluble drugs.

Diethyldithiocarbamate encapsulation reduces toxicity and promotes leishmanicidal effect through apoptosis-like mechanism in promastigote and ROS production by macrophage.

The use of compounds from natural or synthetic sources and nanotechnology may represent an alternative to develop new drugs for the leishmaniasis treatment. DETC is an inhibitor of the SOD1 enzyme, which leads to increased ROS production, important for the elimination of Leishmania. Thus, our objective was to assess the leishmanicidal in vitro effect of free Diethydithiocarbamate (DETC) and DETC loaded in beeswax-copaiba oil nanoparticles (DETC-Beeswax-CO Nps) on L. amazonensis forms and elucidate the possible mechanisms involved in the parasite death. DETC-Beeswax-CO Nps presented size below 200 nm, spherical morphology, negative zeta potential, and high encapsulation efficiency. Free DETC reduced the viability of promastigotes and increase ROS production, lower the mitochondrial membrane potential, cause phosphatidylserine exposure, and enhance plasma membrane permeability, in addition to promoting morphological changes in the parasite. Free DETC proved toxic in the assessment of toxicity to murine macrophages, however, the encapsulation of this compound was able to reduce these toxic effects on macrophages. DETC-Beeswax-CO Nps exerted anti-amastigote effect by enhancing the production of ROS, superoxide anion, TNF-α, IL-6, and reduced IL-10 in macrophages. Therefore, free DETC induces antipromastigote effect by apoptosis-like; and DETC-Beeswax-CO Nps exerted anti-leishmanial effect due to pro-oxidant and pro-inflammatory response.

Effects of the solid lipid nanoparticle of carvacrol on rodents with lung injury from smoke inhalation.

The aim of this present study was to evaluate the effect of solid lipid nanoparticles (SLN) containing carvacrol over the lung damage of airway smoke inhalation. The study was conducted with 30 rats subjected to smoke inhalation and divided into 5 groups such as, normal control, negative control, oxygen group, SLN alone, and SLN+CARV group. The animals were sacrificed 24 h after the induction of inhalation injury further, the tissues of larynx, trachea, and lungs were collected for the histological, hematological, myeloperoxidase, and malondialdehyde analysis. The obtained results showed that treatment with CARV+SLN minimized the inhalation injury, since it reduced malondialdehyde significantly, when compared to the negative control group and minimized the histological changes which proves the absence of pulmonary emphysema and exudate in laryngeal and tracheal lumen in the CARV+SLN-treated group. Meanwhile, the presence of lesion with chronic characteristics was observed in the negative control and oxygen groups. It is suggested that the SLN containing carvacrol minimized oxidative stress and histological damages generated from smoke inhalation in rodents.

Targeted Liposomes for siRNA Delivery to Cancer.

BACKGROUND: RNA interference is a promising therapeutic tool for the treatment of a variety of diseases, with great potential for cancer therapy. Small interfering RNA (siRNA), however, presents several drawbacks that hamper its therapeutic application. Lipid nanoparticles, including liposomes, are delivery systems with great potential for siRNA delivery, protecting it from degradation, enhancing its cell uptake with the ability of controlled release. However, non-specific delivery and side effects could potentially limit the in vivo application. Therefore, targeting lipid nanoparticles to overexpressed receptors of cancer cells represents a strategy for better therapeutic outcome, with improved efficacy and reduced toxicity. For this purpose, lipid nanoparticles could be functionalized with several moieties that can be recognized by cancer cells more than by normal cells. These ligands include folate, transferrin, peptides, oligosaccharides, monoclonal antibodies and aptamers. METHODS: In this paper, we reviewed functionalization strategies and addressed the major in vitro and in vivo findings in the field of cancer treatment with siRNA. RESULTS: Many papers showed enhanced siRNA delivery by targeted liposomes, resulting in enhanced drug uptake and better cytotoxicity, with consequent better tumor growth control in xenograft studies. CONCLUSION: siRNA delivery mediated by functionalized liposomes is promising, but clinical trials need to be conducted.

Development and Evaluation of Lipid Nanoparticles Containing Natural Botanical Oil for Sun Protection: Characterization and in vitro and in vivo Human Skin Permeation and Toxicity.

The use of sunscreen products is widely promoted by schools, government agencies, and health-related organizations to minimize sunburn and skin damage. In this study, we developed stable solid lipid nanoparticles (SLNs) containing the chemical UV filter octyl methoxycinnamate (OMC). In parallel, we produced similar stable SLNs in which 20% of the OMC content was replaced by the botanical urucum oil. When these SLNs were applied to the skin of human volunteers, no changes in fluorescence lifetimes or redox ratios of the endogenous skin fluorophores were seen, suggesting that the formulations did not induce toxic responses in the skin. Ex vivo (skin diffusion) tests showed no significant penetration. In vitro studies showed that when 20% of the OMC was replaced by urucum oil, there was no reduction in skin protection factor (SPF), suggesting that a decrease in the amount of chemical filter may be a viable alternative for an effective sunscreen, in combination with an antioxidant-rich vegetable oil, such as urucum. There is a strong trend towards increasing safety of sun protection products through reduction in the use of chemical UV filters. This work supports this approach by producing formulations with lower concentrations of OMC, while maintaining the SPF. Further investigations of SPF in vivo are needed to assess the suitability of these formulations for human use.

Preparation and characterization of non-viral gene delivery systems with pEGFP-C1 Plasmid DNA

ABSTRACT In recent years, non-viral delivery systems for plasmid DNA have become particularly important. They can overcome the disadvantages of viral systems such as insertional mutagenesis and unpredicted immunogenicity. Some additional advantages of non-viral gene delivery systems are; good stability, low cost, targetability, delivery of a high amount of genetic materials. The aim of the study was to develop novel non-viral nanosystems suitable for gene delivery. Two formulations were developed for this purpose: water-in-oil microemulsion (ME) and solid lipid nanoparticles (SLN). The microemulsion was composed of Peceol, Tween 80, Plurol oleique, ethanol and water. The SLN was consisting of Precirol, Esterquat-1 (EQ1), Tween 80, Lecithin, ethanol and water. Characterization studies were carried out by measuring particle size, zeta potential, viscosity and pH. TEM imaging was performed on SLN formulations. Protection against DNase I degradation was examined. Cytotoxicity and transfection efficacy of selected formulations were tested on L929 mouse fibroblast cells. Particle sizes of complexes were below 100 nm and with high positive zeta potential. TEM images revealed that SLNs are spherical. The SLN:DNA complexes have low toxicity and good transfection ability. All results showed that the developed SLN formulations can be considered as suitable non-viral gene delivery systems.

Lipid- and Polymer-Based Nanostructures for Cutaneous Delivery of Curcumin.

It is well-known that nanoencapsulation may overcome biopharmaceutical limitations of curcumin (CUR), but studies regarding the contribution of the vesicular nature of CUR-loaded nanoparticles on skin permeation are still scarce. Therefore, the effect of three colloidal systems (solid lipid nanoparticles (SLN), nanoemulsion (NE), and polymeric nanoparticles (NP)) on the control of cutaneous permeation of CUR was investigated in porcine ear skin/Franz diffusion cells. Colloidal suspensions were designed to present a similar particle size (±170 nm), narrow size distribution (PdI < 0.2), and high entrapment efficiency (>99%). Zeta potential values were -0.13, -9.68 and -36.7 mV for the CUR-loaded NP, SLN and NE, respectively. Nanoencapsulation resulted in a cumulative amount of CUR in the more superficial layers of the skin. NP significantly enhanced the compound retention in the epidermis, which was approximately 2.49- and 3.32-fold more than SLN and NE, respectively. The CUR levels into the dermis were significantly increased after treatment with NE, which may be associated with repulsion phenomena in surface skin. Therefore, a more superficial or deeper action of CUR on the skin may be obtained depending on nanostructure type. While NPs are more effective in upper skin layers, NE should be prioritized when a dermal action for the CUR is required.

Clobetasol-loaded nanostructured lipid carriers for epidermal targeting.

OBJECTIVES: The aim of this study was to investigate in vitro the epidermal targeting potential of clobetasol propionate-loaded nanostructured lipid carriers (CP-NLC) when compared to that of chitosan-coated (CP-NLC-C). METHODS: CP-NLC were prepared by microemulsion method and characterized by dynamic light scattering, transmission electron microscopy, in vitro release and permeation studies. To verify epidermal targeting, permeation studies were performed in two sets of experiments. For the first set, the skin was removed from the diffusion cell and stratum corneum (SC) was separated from the remaining skin (RS). For the second set, the whole epidermis (EP) was separated from the dermis (DER). CP quantification was performed in each skin layer. KEY FINDINGS: A novel clobetasol propionate-loaded NLC was produced with 1/5th of the drug dose used in commercial formulations and, even so, presented greater skin permeation. Both chitosan-coated and uncoated NLC enhanced the amount of CP in the epidermis more than 80-fold when compared to the commercial formulation (20.26 ± 2.77; 17.85 ± 0.49 and 0.22 ± 0.02 µg/cm(2) , respectively). Differently from chitosan-coated NLC, the uncoated NLC did not show dermal retention. CONCLUSIONS: NLC proved to be a system with potential for targeting drug delivery to the epidermal layer.

Physicochemical characterization by AFM, FT-IR and DSC and biological assays of a promising antileishmania delivery system loaded with a natural Brazilian product.

The control and treatment of Leishmaniasis, a neglected and infectious disease affecting approximately 12 million people worldwide, are challenging. Leishmania parasites multiply intracellularly within macrophages located in deep skin and in visceral tissues, and the currently employed treatments for this disease are subject to significant drawbacks, such as resistance and toxicity. Thus, the search for new Leishmaniasis treatments is compulsory, and Ocotea duckei Vattimo, a plant-derived product from the biodiverse Brazilian flora, may be a promising new treatment for this disease. In this regard, the aim of this work was to develop and characterize a delivery system based on solid lipid nanoparticles (SLN) that contain the liposoluble lignan fraction (LF) of Ocotea duckei Vattimo, which targets the Leishmania phagolysosome of infected macrophages. LF-loaded SLNs were obtained via the hot microemulsion method, and their physical and chemical properties were comprehensively assessed using PCS, AFM, SEM, FT-IR, DSC, HPLC, kinetic drug release studies, and biological assays. The size of the developed delivery system was 218.85±14.2 nm, its zeta potential was -30 mV and its entrapment efficiency (EE%) was high (the EEs% of YAN [yangambin] and EPI-YAN [epi-yangambin] markers were 94.21±0.40% and 94.20±0.00%, respectively). Microscopy, FT-IR and DSC assays confirmed that the delivery system was nanosized and indicated a core-shell encapsulation model, which corroborated the measured kinetics of drug release. The total in vitro release rates of YAN and EPI-YAN in buffer (with sink conditions attained) were 29.6±8.3% and 34.3±8.9%, respectively, via diffusion through the cellulose acetate membrane of the SLN over a period of 4 h. After 24 h, the release rates of both markers reached approximately 45%, suggesting a sustained pattern of release. Mathematical modeling indicated that both markers, YAN and EPI-YAN, followed matrix diffusion-based release kinetics (Higuchi's model) with an estimated diffusion coefficient (D) of 1.3.10(-6) cm(2)/s. The LF-loaded SLNs were non-toxic to murine macrophages (20-80 µg mL(-1) range) and exerted a prominent anti-leishmanial effect (20 µg mL(-1)). These data suggest this new and well-characterized lipid nanoparticle delivery system safely and effectively kills Leishmania and warrants further clinical investigation.

Skin Delivery and in Vitro Biological Evaluation of Trans-Resveratrol-Loaded Solid Lipid Nanoparticles for Skin Disorder Therapies.

The aim of this study was to evaluate the skin delivery and in vitro biological activity of trans-resveratrol (RES)-loaded solid lipid nanoparticles (SLNs). The SLNs were composed of stearic acid, poloxamer 407, soy phosphatidylcholine (SPC), an aqueous phase and 0.1% RES. The particle size, polydispersity index (PdI) and zeta potential were analyzed by dynamic light scattering (DLS). The SLNs were analyzed by scanning electron microscopy (SEM-FEG) and differential scanning calorimetry (DSC). In vitro RES-SLN skin permeation/retention assays were conducted, and their tyrosinase inhibitory activity was evaluated. An MTT reduction assay was performed on HaCat keratinocytes to determine in vitro cytotoxicity. The formulations had average diameter lower than 200 nm, the addition of SPC promoted increases in PdI in the RES-SLNs, but decreases PdI in the RES-free SLNs and the formulations exhibited zeta potentials smaller than -3 mV. The DSC analysis of the SLNs showed no endothermic peak attributable to RES. Microscopic analysis suggests that the materials formed had nanometric size distribution. Up to 45% of the RES permeated through the skin after 24 h. The RES-loaded SLNs were more effective than kojic acid at inhibiting tyrosinase and proved to be non-toxic in HaCat keratinocytes. The results suggest that the investigated RES-loaded SLNs have potential use in skin disorder therapies.

α-Tocopherol succinate improves encapsulation and anticancer activity of doxorubicin loaded in solid lipid nanoparticles.

This work aimed to develop solid lipid nanoparticles (SLN) co-loaded with doxorubicin and α-tocopheryl succinate (TS), a succinic acid ester of α-tocopherol that exhibits anticancer actions, evaluating the influence of TS on drug encapsulation efficiency. The SLN were characterized for size, zeta potential, entrapment efficiency (EE), and drug release. Studies of in vitro anticancer activity were also conducted. The EE was significantly improved from 30 ± 1% to 96 ± 2% for SLN without and with TS at 0.4%, respectively. In contrast, a reduction in particle size from 298 ± 1 to 79 ± 1 nm was observed for SLN without and with TS respectively. The doxorubicin release data show that SLN provide a controlled drug release. The in vitro studies showed higher cytotoxicity for doxorubicin-TS-loaded SLN than for free doxorubicin in breast cancer cells. These findings suggest that TS-doxorubicin-loaded SLN is a promising alternative for the treatment of cancer.

ß-Carotene-loaded nanostructured lipid carriers produced by solvent displacement method.

Tristearin solid lipid nanoparticles and tristearin/high oleic sunflower oil nanostructured lipid carriers were produced by solvent displacement method. All conditions allowed forming polydisperse particles within nanometric range and the presence of high oleic sunflower oil did not affect the particles mean size. Nevertheless, incorporation of ß-carotene reduced the particles polydispersity. Thermograms of solid lipid nanoparticles and nanostructured lipid carriers showed that sunflower oil generated a crystal order disturbance, since nanoparticles with less-organized lipid matrix were produced. Nanostructured lipid carriers exhibited an improvement of ß-carotene loading capacity when compared with solid lipid nanoparticles, which enhanced with the increasing of high oleic sunflower oil content. Although total ß-carotene degradation was similar for all systems, color analysis showed that the degradation of encapsulated ß-carotene was lower for high sunflower oil content. Nanostructured lipid carriers exhibited advantages over the solid lipid nanoparticles, such as enhanced drug loading capacity and prevention of drug expulsion, which makes this a versatile delivery system for food applications.