Polymersomes for Sustained Delivery of a Chalcone Derivative Targeting Glioblastoma Cells.

Glioblastoma (GBM) is a primary malignant tumor of the central nervous system responsible for the most deaths among patients with primary brain tumors. Current therapies for GBM are not effective, with the average survival of GBM patients after diagnosis being limited to a few months. Chemotherapy is difficult in this case due to the heterogeneity of GBM and the high efficacy of the blood-brain barrier, which makes drug absorption into the brain extremely difficult. In a previous study, 3',4',3,4,5-trimethoxychalcone (MB) showed antiproliferative and anti-invasion activities toward GBM cells. Polymersomes (PMs) are an attractive, new type of nanoparticle for drug administration, due to their high stability, enhanced circulation time, biodegradability, and sustained drug release. In the present study, different MB formulations, PEG2000-PCL and PEG5000-PCL, were synthesized, characterized, and compared in terms of 14-day stability and in vitro cytotoxicity (hCMEC/D3 and U-373 MG).

The Synthesis and Characterization of a Delivery System Based on Polymersomes and a Xanthone with Inhibitory Activity in Glioblastoma.

Glioblastoma (GBM) is the most common and deadly primary malignant brain tumor. Current therapies are insufficient, and survival for individuals diagnosed with GBM is limited to a few months. New GBM treatments are urgent. Polymeric nanoparticles (PNs) can increase the circulation time of a drug in the brain capillaries. Polymersomes (PMs) are PNs that have been described as having attractive characteristics, mainly due to their stability, prolonged circulation period, biodegradability, their ability to sustain the release of drugs, and the possibility of surface functionalization. In this work, a poly(ethylene glycol)-ε-caprolactone (PEG-PCL) copolymer was synthesized and PMs were prepared and loaded with an hydrolytic instable compound, previously synthesized by our research team, the 3,6-bis(2,3,4,6-tetra-O-acetyl-ß-glucopyranosyl)xanthone (XGAc), with promising cytotoxicity on glioblastoma cells (U-373 MG) but also on healthy cerebral endothelial cells (hCMEC/D3). The prepared PMs were spherical particles with uniform morphology and similar sizes (mean diameter of 200 nm) and were stable in aqueous suspension. The encapsulation of XGAc in PMs (80% encapsulation efficacy) protected the healthy endothelial cells from the cytotoxic effects of this compound, while maintaining cytotoxicity for the glioblastoma cell line U-373 MG. Our studies also showed that the prepared PMs can efficiently release XGAc at intratumoral pHs.

Nanostructured Lipid Carriers as Robust Systems for Lupeol Delivery in the Treatment of Experimental Visceral Leishmaniasis.

Leishmaniasis is a neglected tropical disease that affects millions of people around the world. Available therapy causes severe side effects, has unacceptable prices for some specific formulations, and the existence of drug-resistant parasites limits the use of the currently available arsenal of antiparasitic drugs. Therefore, natural products serve as one of the main sources to develop new and effective alternative drugs against leishmaniasis. In this sense, the present study evaluated the potential of the triterpene Lupeol (Lu) entrapped in nanostructured lipid carriers (NLCs) for the treatment of experimental visceral leishmaniasis. The therapeutic efficacy of Lu or Lu entrapped in NLC (Lu-NLC) was investigated in golden hamsters infected with Leishmania (Leishmania) infantum. Lu-NLC presented a mean particle size of 265.3 ± 4.6 nm, a polydispersity index of <0.25 and a zeta potential of -37.2 ± 0.84 mV; the efficacy of encapsulation was 84.04 ± 0.57%. Studies on hamsters showed that Lu-NLC (5 mg/kg) administered intraperitoneally for 10 consecutive days caused a reduction of 99.9% in the number of parasites in the spleen and liver compared to the untreated infected control. On the contrary, Lu-treated animals (5 mg/kg) had 94.4 and 90.2% less parasites in the spleen and liver, respectively, than the infected group. Additionally, a significant preservation of splenic and hepatic tissues was observed in animals treated with Lu-NLC or Lu. Furthermore, Lu-NLC-treated animals produced high levels of anti-Leishmania IgG2 isotype. These data indicate that NLC potentialized Lu efficacy in experimental visceral leishmaniasis. This work suggests that Lu and nanoformulations carrying this compound may be considered as an important tool to be included in the alternative therapy of leishmaniasis.

Reviving the interest in the versatile drug nystatin: A multitude of strategies to increase its potential as an effective and safe antifungal agent.

Nystatin is an antifungal molecule with a remarkable yet squandered versatility. In this review, its mechanism of action is explored, along with its extensive action spectrum and toxicity. A multitude of methodologies to tackle the drug's physical and chemical hurdles are outlined along with some proven-effective strategies to increase its activity and/or decrease its toxicity. A separate detailed section focused on micro and nanotechnology solutions addresses new drug delivery systems made of polymeric, metallic or lipid materials. Although the topical route depicts greater representativeness amongst these formulations, the intravenous, dental, oral, vaginal and inhalation routes are also mentioned. The unsuccessful previous attempts at developing parenteral formulations of nystatin or even the withdrawal of a nystatin-loaded multilamellar liposome should not divert research away from this drug. In fact, the interest in nystatin ought to be reawakened with the ongoing clinical trials on the promising nystatin-like genetically engineered derivate BSG005.

Preclinical Assessment of Ursolic Acid Loaded into Nanostructured Lipid Carriers in Experimental Visceral Leishmaniasis.

Ursolic acid, a triterpene produced by plants, displayed leishmanicidal activity in vitro and in vivo; however, the low solubility of this triterpene limits its efficacy. To increase the activity of ursolic acid (UA), this triterpene was entrapped in nanostructured lipid carriers (UA-NLC), physical-chemical parameters were estimated, the toxicity was assayed in healthy golden hamsters, and the efficacy of UA-NLC was studied in experimental visceral leishmanisis. UA-NLC exhibited a spherical shape with a smooth surface with a size of 266 nm. UA-NLC displayed low polydispersity (PDI = 0.18) and good colloidal stability (-29.26 mV). Hamsters treated with UA-NLC did not present morphological changes in visceral organs, and the levels of AST, ALT, urea and creatinine were normal. Animals infected with Leishmania (Leishmania) infantum and treated with UA-NLC showed lower parasitism than the infected controls, animals treated with UA or Amphotericin B (AmB). The therapeutic activity of UA-NLC was associated with the increase in a protective immune response, and it was associated with a high degree of spleen and liver preservation, and the normalization of hepatic and renal functions. These data indicate that the use of lipid nanoparticles as UA carriers can be an interesting strategy for the treatment of leishmaniasis.

Small Molecules of Marine Origin as Potential Anti-Glioma Agents.

Marine organisms are able to produce a plethora of small molecules with novel chemical structures and potent biological properties, being a fertile source for discovery of pharmacologically active compounds, already with several marine-derived agents approved as drugs. Glioma is classified by the WHO as the most common and aggressive form of tumor on CNS. Currently, Temozolomide is the only chemotherapeutic option approved by the FDA even though having some limitations. This review presents, for the first time, a comprehensive overview of marine compounds described as anti-glioma agents in the last decade. Nearly fifty compounds were compiled in this document and organized accordingly to their marine sources. Highlights on the mechanism of action and ADME properties were included. Some of these marine compounds could be promising leads for the discovery of new therapeutic alternatives for glioma treatment.

Oromucosal precursors of in loco hydrogels for wound-dressing and drug delivery in oral mucositis: Retain, resist, and release.

Oromucosal films and tablets were developed as multifunctional biomaterials for the treatment of oral mucositis. These are intended to function as a hybrid, performing as a controlled drug delivery system and as a wound-dressing device. The dosage forms are precursors for in loco hydrogels that are activated by the saliva. An anti-inflammatory and anesthetic activity is attained from budesonide tripartite polymeric nanoparticles and lidocaine, while the polymeric network allows the protection and cicatrization of the wound. Different biomaterials and blends were investigated, focusing on the capacity to retain and resist on-site, as well as achieve a long-lasting controlled release. As the limiting factor, the choice was made according to the films' results. A polymer mix of Methocel™ K100M and Carbopol® (974P, EDT 2020, or Ultrez 10) blends were used. Overall, regrading critical factors, Carbopol® increased films' elasticity and flexibility, mucoadhesion, and the strength of the hydrogels, while higher concentrations led to thicker, more opaque, and lower strain resistance products. Whereas 974P and Ultrez 10 performed similarly, EDT 2020 led to uniformity problems and weaker films, hydrogels and bioadhesion. The optimized products were enhanced with sodium hyaluronate and drug-loaded for further characterization. Concerning the dosage form, the films' hydrogels were more resilient, while the tablets had higher mucoadhesiveness and longer swelling. Although through different networks and mechanisms, both dosage forms and grades revealed similar release profiles. A Case II time-evolving stereoselectivity for the 22R and 22S budesonide epimers was found, and Fickian-diffusion for lidocaine. Ultimately, the developed formulations show great potential to be used in OM management. Both of the selected grades at 0.6% displayed excellent performance, while Ultrez 10 can be preferable for the films' production due to its lower viscosity before neutralization and higher after activation. Where the tablets are easier to produce and offer better adhesion, the films are more customizable post-production and have higher rheological performance for wound-dressing.

Lipid nanoparticles coated with chitosan using a one-step association method to target rifampicin to alveolar macrophages.

This work proposes the development and characterization of solid lipid nanoparticles (SLNs) loaded with rifampicin (RIF) aiming to enhance mucoadhesion of the SLNs and consequently internalization by the alveolar macrophages (AMs). The lipid nanoparticles (NPs) were characterized and the results showed that the NPs obtained present a spherical or a starry shape with diameter around 250-500 nm, a monodisperse population, with zeta potential between -31 mV for uncoated SLNs and +33 mV for coated SLNs. The drug EE was approximately 90 % and the loading capacity (LC) 4.5 %. The SLNs coated with chitosan by the association method (aC-SLNs) show an effective mucoadhesive profile, verified by the turdimetry and surface loading method, corroborated with the cellular assays. The presence of chitosan in the aC-SLNs promotes higher mucoadhesive properties to the NPs and permeability in A549, suggesting that the safe aC-SLNs-RIF can be used as a promising drug delivery system for improving tuberculosis treatment.

Current Insights on Antifungal Therapy: Novel Nanotechnology Approaches for Drug Delivery Systems and New Drugs from Natural Sources.

The high incidence of fungal infections has become a worrisome public health issue, having been aggravated by an increase in host predisposition factors. Despite all the drugs available on the market to treat these diseases, their efficiency is questionable, and their side effects cannot be neglected. Bearing that in mind, it is of upmost importance to synthetize new and innovative carriers for these medicines not only to fight emerging fungal infections but also to avert the increase in drug-resistant strains. Although it has revealed to be a difficult job, new nano-based drug delivery systems and even new cellular targets and compounds with antifungal potential are now being investigated. This article will provide a summary of the state-of-the-art strategies that have been studied in order to improve antifungal therapy and reduce adverse effects of conventional drugs. The bidirectional relationship between Mycology and Nanotechnology will be also explained. Furthermore, the article will focus on new compounds from the marine environment which have a proven antifungal potential and may act as platforms to discover drug-like characteristics, highlighting the challenges of the translation of these natural compounds into the clinical pipeline.

Protocol for the use of legacy data and magnetic signature on soil mapping of São Paulo Central West, Brazil.

The demand for information on the soil resource to support the establishment of public policies for land use and management has grown exponentially in the last years. However, there are still difficulties to the proper use of already existing information for soil mapping. Here we aimed to establish a protocol for soil mapping using legacy data, magnetic signature and soil attributes evaluation. A total of 493 soil samples were collected at 0-0.20 m in the geological domain of Western Plateau of São Paulo State. This work has three parts: First, we performed a classification analysis using soil mapping units (SMU) extracted from conventional soil map and Support Vector Machines algorithm (SVM). As covariates, we used categorical information, such as geology, dissection and landform maps. Second, we used soil attributes to perform a cluster analysis using k-means as partitioning method. To choose the optimal number of clusters, the same number of SMU showed in the conventional soil map (e.g. 34 clusters) were used. The last step was to compare soil and clusters maps predicted by SVM with the conventional soil map. Results showed good performance of SVM for both classifications (clusters and SMU), with overall accuracy of 0.60 and 0.90 respectively. In addition, the distribution of soil attributes within each cluster was more homogeneous and well distributed than within SMU, showing that is very possible to use numerical classification for soil mapping. Future soil surveys could use cluster analysis as a preliminary evaluation for better understanding of tropical soil variations.

Swellable polymeric particles for the local delivery of budesonide in oral mucositis.

Topical drug delivery in the oral mucosa has its set of challenges due to the unique anatomical and physiological features of the oral cavity. As such, the outcomes of local pharmacological treatments in oral disorders can fail due to unsuccessfully drug delivery. Oral mucositis, a severe inflammatory and ulcerative side effect of oncological treatments, is one of such diseases. Although the damaged tissue is within reach, no approved topical drug treatment is available. Several strategies based on its physiopathology have been implemented and clinically used. Even so, results tend to lack or be insufficient to improve patient's quality of life. The use of corticosteroids has been employed in such strategies due to their strong anti-inflammatory action. Typically, these are administrated in simple liquid formulations, where the drug is dispersed or solubilized, lacking the ability to maintain local concentration. In this work, we propose the development of a biocompatible delivery system with boosted abilities of retention and control release of budesonide, a corticosteroid with an elevated ratio of topical anti-inflammatory to systemic action. Through spray-drying, polymeric particles of Chitosan and Eudragit® E PO were produced and characterized for the vectorization of this drug.

pH-responsive chitosan based hydrogels affect the release of dapsone: Design, set-up, and physicochemical characterization.

Dapsone (DAP) is a bactericidal agent used in the treatment of leprosy, caused by Mycobacterium leprae. Despite its therapeutic potential, DAP has low solubility, which results in allow therapeutic index and a high microbial resistance. Recently, new approaches were used to increase the DAP solubility. In particular, the use of interpenetrating polymer network (IPN)-hydrogels based chitosan (CS) for the controlled release of DAP provides some advantages because they can modify their swelling properties and network structures as a response to environmental stimuli. The aim of this study was to synthesize and physicochemically characterize pH-responsive chitosan/polymer hydrogels to control the release of DAP. For this reason, different combination of polymers, such as polyvinyl pyrrolidone, polyethylene glycol and hydroxypropyl methylcellulose, and concentrations of the cross-linking agents (glutaraldehyde) were used and then blended to the CS. The resulting hydrogels were evaluated in terms of physicochemical and swelling properties, rheological analysis and in vitro release of DAP at different pHs (1.2-6.8). Hydrogels were further characterized by Fourier transformed infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) analysis. pH-responsive DAP-loaded hydrogels may represent the set-up for developing potential oral formulations for the treatment of leprosy caused by Mycobacterium leprae.

Discovery of a New Xanthone against Glioma: Synthesis and Development of (Pro)liposome Formulations.

Following our previous work on the antitumor activity of acetylated flavonosides, a new acetylated xanthonoside, 3,6-bis(2,3,4,6-tetra-O-acetyl-ß-glucopyranosyl)xanthone (2), was synthesized and discovered as a potent inhibitor of tumor cell growth. The synthesis involved the glycosylation of 3,6-di-hydroxyxanthone (1) with acetobromo-α-d-glucose. Glycosylation with silver carbonate decreased the amount of glucose donor needed, comparative to the biphasic glycosylation. Xanthone 2 showed a potent anti-growth activity, with GI50 < 1 µM, in human cell lines of breast, lung, and glioblastoma cancers. Current treatment for invasive brain glioma is still inadequate and new agents against glioblastoma with high brain permeability are urgently needed. To overcome these issues, xanthone 2 was encapsulated in a liposome. To increase the well-known low stability of these drug carriers, a proliposome formulation was developed using the spray drying method. Both formulations were characterized and compared regarding three months stability and in vitro anti-growth activity. While the proliposome formulation showed significantly higher stability, it was at the expense of losing its biocompatibility as a drug carrier in higher concentrations. More importantly, the new xanthone 2 was still able to inhibit the growth of glioblastoma cells after liposome formulation.

Resource Loss Moderates the Association Between Child Abuse and Current PTSD Symptoms Among Women in Primary-Care Settings.

This study examined if abuse during childhood, rape in adulthood, and loss of resources predict a woman's probability of reporting symptoms of posttraumatic stress disorder (PTSD), and whether resource loss moderates the association between reporting childhood abuse and PTSD symptoms. The sample included 767 women and was collected in publicly funded primary-care settings. Women who reported having been abused during childhood also reported more resource loss, more acute PTSD symptoms, and having suffered more adult rape than those who reported no childhood abuse. Hierarchical logistic regression yielded a two-variable additive model in which child abuse and adult rape predict the probability of reporting or not any PTSD symptoms, explaining 59.7% of the variance. Women abused as children were 1 to 2 times more likely to report PTSD symptoms, with sexual abuse during childhood contributing most strongly to this result. Similarly, women reporting adult rape were almost twice as likely to report symptoms of PTSD as those not reporting it. Resource loss was unexpectedly not among the predictors but a moderation analysis showed that such loss moderated the association between child abuse and current PTSD symptoms, with resource loss increasing the number and severity of PTSD symptoms in women who also reported childhood abuse. The findings highlight the importance of early assessment and intervention in providing mental health care to abused, neglected, and impoverished women to help them prevent and reverse resource loss and revictimization.

Nanosystems as modulators of intestinal dapsone and clofazimine delivery.

The aim of this work was to assess the feasibility of drug nanosystems combination for oral therapy of multibacillary leprosy. The anti-leprotic drugs dapsone (DAP) and clofazimine (CLZ) were incorporated within polymeric nanosystems and studied per se and in combination. DAP was loaded in Eudragit L100 nanoparticles (NPs-DAP) while CLZ was loaded in (poly(lactic-co-glycolic acid) (NPs-CLZ). The nanosystems exhibited around 200 nm in size and a drug loading of 12% for each drug. In vitro cytotoxicity on intestinal Caco-2 cells revealed that after 8 h incubation, DAP alone and within NPs were not toxic up to 100 µg mL-1, while CLZ per se was toxic, reducing cell viability to 30% at 50 µg mL-1. Caco-2 exposed to the combination of NPs-DAP (100 µg mL-1) and NPs-CLZ (50 µg mL-1) exhibited 80% of viability. Caco-2 monolayer permeability assays revealed that DAP and CLZ in the nanosystems per se or in NPs-DAP/ NPs-CLZ combination crossed the intestinal barrier. No significant differences were observed between the single nanosystems or in combination with the apparent permeability values and the amount of permeated drug. Thus, the NPs-DAP/NPs-CLZ combination seems to be a promising platform to deliver both drugs in association, representing an important step towards the improvement of multibacillary leprosy therapy.

Challenges in the local delivery of peptides and proteins for oral mucositis management.

Oral mucositis, a common inflammatory side effect of oncological treatments, is a disorder of the oral mucosa that can cause painful ulcerations, local motor disabilities, and an increased risk of infections. Due to the discomfort it produces and the associated health risks, it can lead to cancer treatment restrains, such as the need for dose reduction, cycle delays or abandonment. Current mucositis management has low efficiency in prevention and treatment. A topical drug application for a local action can be a more effective approach than systemic routes when addressing oral cavity pathologies. Local delivery of growth factors, antibodies, and anti-inflammatory cytokines have shown promising results. However, due to the peptide and protein nature of these novel agents, and the several anatomic, physiological and environmental challenges of the oral cavity, their local action might be limited when using traditional delivering systems. This review is an awareness of the issues and strategies in the local delivery of macromolecules for the management of oral mucositis.

Overcoming clofazimine intrinsic toxicity: statistical modelling and characterization of solid lipid nanoparticles.

The aim of this work was to develop solid lipid nanoparticles (SLNs) loaded with clofazimine (CLZ) (SLNs-CLZ) to overcome its intrinsic toxicity and low water solubility, for oral drug delivery. A Box-Behnken design was constructed to unravel the relations between the independent variables in the selected responses. The optimized SLNs-CLZ exhibited the following properties: particle size ca 230 nm, zeta potential of -34.28 mV, association efficiency of 72% and drug loading of 2.4%, which are suitable for oral delivery. Further characterization included Fourier transformed infrared spectroscopy that confirmed the presence of the drug and the absence of chemical interactions. By differential scanning calorimetry was verified the amorphous state of CLZ. The storage stability studies ensured the stability of the systems over a period of 12 weeks at 4°C. In vitro cytotoxicity studies evidenced no effect of both drug-loaded and unloaded SLNs on MKN-28 gastric cells and on intestinal cells, namely Caco-2 and HT29-MTX cells up to 25 µg ml-1 in CLZ. Free CLZ solutions exhibited IC50 values of 16 and 20 µg ml-1 for Caco-2 and HT29-MTX cells, respectively. It can be concluded that the optimized system, designed considering important variables for the formulation of poorly soluble drugs, represents a promising platform for oral CLZ delivery.

Mannosylated solid lipid nanoparticles for the selective delivery of rifampicin to macrophages.

Tuberculosis (TB) is still a devastating disease and more people have died of TB than any other infectious diseases throughout the history. The current therapy consists of a multidrug combination in a long-term treatment, being associated with the appearance of several adverse effects. Thus, solid lipid nanoparticles (SLNs) were developed using mannose as a lectin receptor ligand conjugate for macrophage targeting and to increase the therapeutic index of rifampicin (RIF). The developed SLNs were studied in terms of diameter, polydispersity index, zeta potential, encapsulation efficiency (EE) and loading capacity (LC). Morphology, in vitro drug release and differential scanning calorimetry studies, macrophage uptake studies, cell viability and storage stability studies were also performed. The diameter of the SLNs obtained was within the range of 160-250 nm and drug EE was above 75%. The biocompatibility of M-SLNs was verified and the internalization in macrophages was improved with the mannosylation. The overall results suggested that the developed mannosylated formulations are safe and a promising tool for TB therapy targeted for macrophages.

Synthesis and characterization of Locust Bean Gum derivatives and their application in the production of nanoparticles.

The development of LBG-based nanoparticles intending an application in oral immunization is presented. Nanoparticle production occurred by mild polyelectrolyte complexation, requiring the chemical modification of LBG. Three LBG derivatives were synthesized, namely a positively charged ammonium derivative (LBGA) and negatively charged sulfate (LBGS) and carboxylate (LBGC) derivatives. These were characterized by Fourier-transform infrared spectroscopy, elemental analysis, nuclear magnetic resonance spectroscopy, gel permeation chromatography, and x-ray diffraction. As a pharmaceutical application was aimed, a toxicological analysis of the derivatives was performed by both MTT test and LDH release assay. Several nanoparticle formulations were produced using LBGA or chitosan (CS) as positively charged polymers, and LBGC or LBGS as negatively charged counterparts, producing nanoparticles with adequate properties regarding an application in oral immunization.

Development of PLGA nanoparticles loaded with clofazimine for oral delivery: Assessment of formulation variables and intestinal permeability.

The use of polymeric nanoparticles as delivery systems is a promising tool to overcome drawbacks related to low aqueous solubility of drugs, which limit their in vivo bioavailability. The aim of this study was to decrease clofazimine (CLZ) toxicity using experimental design to formulate CLZ loaded in PLGA nanoparticles (NPs-CLZ) through a Plackett-Burman design (PBD). A screening PBD was constructed with twelve formulations involving six variables among process and formulation parameters and the selected responses were particle size, polydispersity index (PDI), association efficiency (AE) and drug loading (DL). The formulation was achieved based on the desirability tool, and the obtained NPs-CLZ formulation was characterized regarding morphology, physicochemical properties, in vitro release and cellular studies. Particle size, PDI, AE and DL were found to be 211±3nm, 0.211±0.009, 70±5% and 12±1%, respectively. Physicochemical studies confirmed the absence of chemical interactions between CLZ and other nanoparticles constituents and the amorphous state of CLZ, while morphological analysis revealed the spherical shape of the particles. In vitro release profile of CLZ from NPs-PLGA showed a slow pattern of drug release. Cell viability studies towards intestinal cells revealed that NPs-CLZ did not show CLZ toxicity on Caco-2 and HT29-MTX cells compared to free CLZ solutions. Moreover, CLZ could permeate Caco-2 monolayers substantially at the end of 8h. It can be concluded that the proposed NPs-CLZ represent a promising platform to the oral delivery of CLZ as they were able to decrease its intrinsic toxicity, with improved absorption.