Lipid-core nanocapsules containing simvastatin do not affect the biochemical and hematological indicators of toxicity in rats

Our research group previously studied the effectiveness of lipid-core nanocapsules (LNC) containing simvastatin (SV-LNC) in treating cognitive impairment in rats. While our results were promising, we needed to evaluate the potential toxicity of the nanoparticles themselves. This study aimed to compare the biochemical and hematological parameters of adult Wistar rats receiving LNC or SV-LNC to those receiving low doses of simvastatin crystals dispersed in a saline solution over 45 days. We discovered that LNC and SV-LNC, which are both nanometers in size with low polydispersity index, negative zeta potential, and high SV encapsulation efficacy, were not more toxic than SV crystals based on various biochemical markers of hepatic, pancreatic, renal, mineral, bony, alkaline phosphatase, glucose, and uric acid damage. Furthermore, LNC exhibited no toxicity for hematological parameters, including red and white blood cell counts. Based on this animal model of toxicological study, our findings suggest that long-term administration of LNC is a safe and promising nanocarrier.

Exposure to virgin and marine incubated microparticles of biodegradable and conventional polymers modulates the hepatopancreas transcriptome of Mytilus galloprovincialis

Biodegradable polymers have been proposed as an alternative to conventional plastics to mitigate the impact of marine litter, but the research investigating their toxicity is still in its infancy. This study evaluates the potential ecotoxicological effects of both virgin and marine-incubated microparticles (MPs), at environmentally relevant concentration (0.1 mg/l), made of different biodegradable polymers (Polycaprolactone, Mater-Bi, cellulose) and conventional polymers (Polyethylene) on Mytilus galloprovincialis by using transcriptomics. This approach is increasingly being used to assess the effects of pollutants on organisms, obtaining data on numerous biological pathways simultaneously. Whole hepatopancreas de novo transcriptome sequencing was performed, individuating 972 genes differentially expressed across experimental groups compared to the control. Through the comparative transcriptomic profiling emerges that the preponderant effect is attributable to the marine incubation of MPs, especially for incubated polycaprolactone (731 DEGs). Mater-Bi and cellulose alter the smallest number of genes and biological processes in the mussel hepatopancreas. All microparticles, regardless of their polymeric composition, dysregulated innate immunity, and fatty acid metabolism biological processes. These findings highlight the necessity of considering the interactions of MPs with the environmental factors in the marine ecosystem when performing ecotoxicological evaluations. The results obtained contribute to fill current knowledge gaps regarding the potential environmental impacts of biodegradable polymers.

Optimizing the formulation variables for encapsulation of linezolid into polycaprolactone inhalable microspheres using double emulsion solvent evaporation

Inhaled antibiotics delivered through dry powder inhalers (DPIs) effectively treat severe bacterial infections by directly targeting the lungs. Our study focused on developing inhalable dry powder microspheres of linezolid (LNZ) using biodegradable polycaprolactone (PCL) polymer. The LNZ-PCL microspheres were fabricated using a double emulsification solvent evaporation method. Optimization of formulation parameters was performed using a factorial design. Evaluation of the microspheres included size, shape, drug loading, entrapment efficiency, aerosolization, and drug release. The morphological analysis confirmed spherical-shaped rough particles within the inhalable size range. The encapsulation efficiency was determined to be 52.84%, indicating successful drug incorporation. Aerosolization efficiency was significantly enhanced when LNZ-PCL microspheres were combined with lactose as a carrier, achieving a fine particle fraction (FPF) value of 70.90%. In-vitro dissolution studies demonstrated sustained drug release for over 24 h under lung pH conditions. Overall, our study highlights the potential of inhalable LNZ-PCL microspheres as a targeted approach for treating pulmonary tuberculosis. Further research and in-vivo studies are needed to validate their effectiveness in life-threatening bacterial infections.

Formulation of Resveratrol-Loaded Polycaprolactone Inhalable Microspheres Using Tween 80 as an Emulsifier: Factorial Design and Optimization

Resveratrol (RSV) is a bioactive phytoconstituent that has potential applications in respiratory diseases. However, poor oral bioavailability is the major hurdle to its clinical use. In the present work, resveratrol-loaded polycaprolactone (PCL) inhalable microspheres (MSs) were formulated to improve their therapeutic potential. The inhalable microspheres were formulated using the emulsion-solvent evaporation method. In this research, inhalable resveratrol microspheres were prepared using Tween 80 in place of polyvinyl alcohol which formed insoluble lumps. A 3² factorial design was applied taking polymer (PCL) and emulsifier (Tween 80) as independent variables and drug loading (DL) and encapsulation efficiency (EE) as dependent variables. The DL and EE of the optimized formulation were found to be 30.6% and 63.84% respectively. The in vitro aerosolization study performed using the Anderson cascade impactor showed that the fine particle fraction (FPF) of optimized resveratrol polycaprolactone microspheres (RSV-PCL-MSs) blended with lactose, and RSV-PCL-MSs were significantly higher than those of the pure drugs. The MMAD_T (theoretical mass median aerodynamic diameter) of optimized RSV-PCL-MSs was found to be 3.25 ± 1.15. The particle size of microspheres was within the inhalable range, i.e., between 1 and 5 µm. The morphological analysis showed spherical-shaped particles with smooth surfaces. The in vitro release study showed sustained drug release from the microspheres for up to 12 h. The study concluded that resveratrol-loaded inhalable microspheres may be an efficient delivery system to treat COPD.

The Virtuous Galleria mellonella Model for Scientific Experimentation

The first research on the insect Galleria mellonella was published 85 years ago, and the larva is now widely used as a model to study infections caused by bacterial and fungal pathogens, for screening new antimicrobials, to study the adjacent immune response in co-infections or in host-pathogen interaction, as well as in a toxicity model. The immune system of the G. mellonella model shows remarkable similarities with mammals. Furthermore, results from G. mellonella correlate positively with mammalian models and with other invertebrate models. Unlike other invertebrate models, G. mellonella can withstand temperatures of 37 °C, and its handling and experimental procedures are simpler. Despite having some disadvantages, G. mellonella is a virtuous in vivo model to be used in preclinical studies, as an intermediate model between in vitro and mammalian in vivo studies, and is a great example on how to apply the bioethics principle of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation. This review aims to discuss the progress of the G. mellonella model, highlighting the key aspects of its use, including experimental design considerations and the necessity to standardize them. A different score in the "cocoon" category included in the G. mellonella Health Index Scoring System is also proposed.

Microfluidic preparation and optimization of sorafenib-loaded poly(ethylene glycol-block-caprolactone) nanoparticles for cancer therapy applications

The use of amphiphilic block copolymers to generate colloidal delivery systems for hydrophobic drugs has been the subject of extensive research, with several formulations reaching the clinical development stages. However, to generate particles of uniform size and morphology, with high encapsulation efficiency, yield and batch-to-batch reproducibility remains a challenge, and various microfluidic technologies have been explored to tackle these issues. Herein, we report the development and optimization of poly(ethylene glycol)-block-(ε-caprolactone) (PEG-b-PCL) nanoparticles for intravenous delivery of a model drug, sorafenib. We developed and optimized a glass capillary microfluidic nanoprecipitation process and studied systematically the effects of formulation and process parameters, including different purification techniques, on product quality and batch-to-batch variation. The optimized formulation delivered particles with a spherical morphology, small particle size (d_H < 80 nm), uniform size distribution (PDI < 0.2), and high drug loading degree (16 %) at 54 % encapsulation efficiency. Furthermore, the stability and in vitro drug release were evaluated, showing that sorafenib was released from the NPs in a sustained manner over several days. Overall, the study demonstrates a microfluidic approach to produce sorafenib-loaded PEG-b-PCL NPs and provides important insight into the effects of nanoprecipitation parameters and downstream processing on product quality.

Safety assessment of different unloaded polymeric nanocapsules in Caenorhabditis elegans

Nano-sized drug delivery systems have been the subject of intense research in recent years because polymeric materials allow the absorption and release of active substances in a controlled manner. Despite the benefits, the safety of nanoparticulate systems is an aspect to be understood, particularly in vivo systems. Caenorhabditis elegans is a very useful alternative model for nanotoxicology and has been recently applied in this field. The aim of this study was to evaluate toxicological endpoints in C. elegans exposed to nanocapsules (NC) prepared with different coatings: polysorbate 80 (NCP80); polyethylene glycol (NCPEG), Eudragit® RS 100 (NCEUD) and chitosan (NCCS). Nanocapsules were prepared by nanoprecipitation method and showed acceptable physico-chemical characterization. Polyethylene glycol nanocapsules and chitosan nanocapsules increased worms lethality in a dose-dependent manner in acute exposure; polysorbate 80 nanocapsules, polyethylene glycol nanocpsules and chitonan nanocapsules also increased lethality following chronic exposure. Chitosan nanocapsules were the most toxic in all exposures, demonstrating toxicity even at low concentrations. Reproduction and body length were not affected by any of the nanocapsules exposures. The expression of superoxide dismutase showed that polysorbate 80 nanocapsules at the highest concentration slightly increased SOD-3::GFP expression. On the other hand, chitosan nanocapsules exposure blunted SOD-3 expression. This work demonstrates the toxicological differences between nanocapsule produced with different coatings and indicates higher safety for the use of eugragit nanocapsule in new formulations for future drug delivery and targeting systems.

Polyester Nanocapsules for Intravenous Delivery of Artemether: Formulation Development, Antimalarial Efficacy, and Cardioprotective Effects In Vivo

Artemether (ATM) is an effective antimalarial drug that also has a short half-life in the blood. Furthermore, ATM is also cardiotoxic and is associated with pro-arrhythmogenic risks. We aimed to develop a delivery system enabling the prolonged release of ATM into the blood coupled with reduced cardiotoxicity. To achieve this, we prepared polymeric nanocapsules (NCs) from different biodegradable polyesters, namely poly(D,L-lactide) (PLA), poly-ε-caprolactone (PCL), and surface-modified NCs, using a monomethoxi-polyethylene glycol-block-poly(D,L-lactide) (PEG5kDa-PLA45kDa) polymer. Using this approach, we were able to encapsulate high yields of ATM (>85%, 0−4 mg/mL) within the oily core of the NCs. The PCL-NCs exhibited the highest percentage of ATM loading as well as a slow release rate. Atomic force microscopy showed nanometric and spherical particles with a narrow size dispersion. We used the PCL NCs loaded with ATM for biological evaluation following IV administration. As with free-ATM, the ATM-PCL-NCs formulation exhibited potent antimalarial efficacy using either the “Four-day test” protocol (ATM total at the end of the 4 daily doses: 40 and 80 mg/kg) in Swiss mice infected with P. berghei or a single low dose (20 mg/kg) of ATM in mice with higher parasitemia (15%). In healthy rats, IV administration of single doses of free-ATM (40 or 80 mg/kg) prolonged cardiac QT and QTc intervals and induced both bradycardia and hypotension. Repeated IV administration of free-ATM (four IV doses at 20 mg/kg every 12 h for 48 h) also prolonged the QT and QTc intervals but, paradoxically, induced tachycardia and hypertension. Remarkably, the incorporation of ATM in ATM-PCL-NCs reduced all adverse effects. In conclusion, the encapsulation of ATM in biodegradable polyester NCs reduces its cardiovascular toxicity without affecting its antimalarial efficacy.

Galleria mellonella: The Versatile Host for Drug Discovery, In Vivo Toxicity Testing and Characterising Host-Pathogen Interactions

Larvae of the greater wax moth, Galleria mellonella, are a convenient in vivo model for assessing the activity and toxicity of antimicrobial agents and for studying the immune response to pathogens and provide results similar to those from mammals. G. mellonella larvae are now widely used in academia and industry and their use can assist in the identification and evaluation of novel antimicrobial agents. Galleria larvae are inexpensive to purchase and house, easy to inoculate, generate results within 24–48 h and their use is not restricted by legal or ethical considerations. This review will highlight how Galleria larvae can be used to assess the efficacy of novel antimicrobial therapies (photodynamic therapy, phage therapy, metal-based drugs, triazole-amino acid hybrids) and for determining the in vivo toxicity of compounds (e.g., food preservatives, ionic liquids) and/or solvents (polysorbate 80). In addition, the disease development processes are associated with a variety of pathogens (e.g., Staphylococcus aureus, Listeria monocytogenes, Aspergillus fumigatus, Madurella mycotomatis) in mammals are also present in Galleria larvae thus providing a simple in vivo model for characterising disease progression. The use of Galleria larvae offers many advantages and can lead to an acceleration in the development of novel antimicrobials and may be a prerequisite to mammalian testing.

Oral delivery of ambrisentan-loaded lipid-core nanocapsules as a novel approach for the treatment of pulmonary arterial hypertension

Ambrisentan (AMB) is an orphan drug approved for oral administration that has been developed for the treatment of pulmonary arterial hypertension (PAH), a chronic and progressive pathophysiological state that might result in death if left untreated. Lipid-core nanocapsules (LNCs) are versatile nanoformulations capable of loading lipophilic drugs for topical, vaginal, oral, intravenous, pulmonary, and nasal administration. Our hypothesis was to load AMB into these nanocapsules (LNC_amb) and test their effect on slowing or reducing the progression of monocrotaline-induced PAH in a rat model, upon oral administration. LNC_amb displayed a unimodal distribution of diameters (around 200 nm), negative zeta potential (-11.5 mV), high encapsulation efficiency (78%), spherical shape, and sustained drug release (50-60% in 24 h). The in vivo pharmacodynamic effect of the LNC_amb group was evaluated by observing the echocardiography, hemodynamic, morphometric, and histological data, which showed a significant decrease in PAH in this group, as compared to the control group (AMB_solution). LNC_amb showed the benefit of reversing systolic dysfunction and preventing vascular remodeling with greater efficacy than that observed in the control group. The originality and contribution of our work reveal the promising value of this nanoformulation as a novel therapeutic strategy for PAH treatment.

Alpha-tocopherol-loaded polycaprolactone nanoparticles improve the inflammation and systemic oxidative stress of arthritic rats

Background and aim

The present study investigated the effects of orally administered α-tocopherol-loaded polycaprolactone nanoparticles on the articular inflammation and systemic oxidative status of middle-aged Holtzman rats with Freund's adjuvant-induced polyarthritis, a model for rheumatoid arthritis. Intraperitoneally administered free α-tocopherol provided the reference for comparison.

Experimental procedure

Two protocols of treatment were followed: intraperitoneal administration of free α-tocopherol (100 mg/kg i.p.) or oral administration of free and nanoencapsulated α-tocopherol (100 mg/kg p.o.). Animals were treated during 18 days after arthritis induction.

Results

Free (i.p.) and encapsulated α-tocopherol decreased the hind paws edema, the leukocytes infiltration into femorotibial joints and the mRNA expression of pro-inflammatory cytokines in the tibial anterior muscle of arthritic rats, but the encapsulated compound was more effective. Free (i.p.) and encapsulated α-tocopherol decreased the high levels of reactive oxygen species in the brain and liver, but only the encapsulated compound decreased the levels of protein carbonyl groups in these organs. Both free (i.p.) and encapsulated α-tocopherol increased the α-tocopherol levels and the ratio of reduced to oxidized glutathione in these organs.

Conclusion

Both intraperitoneally administered free α-tocopherol and orally administered encapsulated α-tocopherol effectively improved inflammation and systemic oxidative stress in middle-aged arthritic rats. However, the encapsulated form should be preferred because the oral administration route does not be linked to the evident discomfort that is caused in general by injectable medicaments. Consequently, α-tocopherol-loaded polycaprolactone nanoparticles may be a promising adjuvant to the most current approaches aiming at rheumatoid arthritis therapy.

•

Oxidative stress is systemically increased in rats with adjuvant-induced arthritis.

•

Arthritic rats were orally treated with α-tocopherol-loaded polycaprolactone nanoparticles.

•

Treatment decreased the paw edema and articular inflammation of arthritic rats.

•

Treatment improved the oxidative stress in the liver and brain arthritic rats.

•

The content of α-tocopherol was increased in the brain and liver of treated rats.

Eplerenone nanocrystals engineered by controlled crystallization for enhanced oral bioavailability

Poor aqueous solubility of eplerenone (EPL) is a major obstacle to achieve sufficient bioavailability after oral administration. In this study, we aimed to develop and evaluate eplerenone nanocrystals (EPL-NCs) for solubility and dissolution enhancement. D-optimal combined mixture process using Design-Expert software was employed to generate different combinations for optimization. EPL-NCs were prepared by a bottom-up, controlled crystallization technique during freeze-drying. The optimized EPL-NCs were evaluated for their size, morphology, thermal behavior, crystalline structure, saturation solubility, dissolution profile, in vivo pharmacokinetics, and acute toxicity. The optimized EPL-NCs showed mean particle size of 46.8 nm. Scanning electron microscopy revealed the formation of elongated parallelepiped shaped NCs. DSC and PXRD analysis confirmed the crystalline structure and the absence of any polymorphic transition in EPL-NCs. Furthermore, EPL-NCs demonstrated a 17-fold prompt increase in the saturation solubility of EPL (8.96 vs. 155.85 µg/mL). The dissolution rate was also significantly higher as indicated by ∼95% dissolution from EPL-NCs in 10 min compared to only 29% from EPL powder. EPL-NCs improved the oral bioavailability as indicated by higher AUC, C_max, and lower T_max than EPL powder. Acute oral toxicity study showed that EPL-NCs do not pose any toxicity concern to the blood and vital organs. Consequently, NCs prepared by controlled crystallization technique present a promising strategy to improve solubility profile, dissolution velocity and bioavailability of poorly water-soluble drugs.

Surface-functionalized curcumin-loaded polymeric nanocapsules could block apomorphine-induced behavioral changes in rats

BACKGROUND

Surface functionalization enhances the properties and characteristics of polymeric nanocapsules (NCs) mainly due to the surface charge, surfactants, and polymer coating type. Curcumin (CUR) is a bioactive compound with several proven pharmacological properties and low bioavailability. This study aimed to develop anionic (poly-ɛ-caprolactone; PCL) and cationic (Eudragit^® RS100 (EUD)) NCs prepared with sorbitan monostearate (Span 60^®) or sorbitan monooleate (Span 80^®), coated with d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and optimized using 2³ factorial analysis. Subsequently, the biological activity was evaluated.

METHODS

A two-level, three-factor design (polymer, Span type, and TPGS concentration) was used. The biological effects of CUR-loaded TPGS-coated cationic and anionic NCs were assessed in apomorphine-induced stereotyped behavior in rats.

RESULTS

The type of polymer (anionic or cationic) and Span^® had a factorial influence on the physical and chemical characteristics of NCs according to the changes in TPGS concentrations. Both cationic and anionic CUR-NCs could block apomorphine-induced behavioral changes.

CONCLUSIONS

The CUR-loaded TPGS-coated NCs proved to be a promising brain delivery system.

New nanotechnological formulation based on amiodarone-loaded lipid core nanocapsules displays anticryptococcal effect

Cryptococcus neoformans is the etiological agent of cryptococcal meningoencephalitis. The recommended available treatment has low efficiency, with high toxicity and resistance as recurrent problems. In the search of new treatment protocols, the proposal of new pharmacological approaches is considered an innovative strategy, mainly nanotechnological systems considering fungal diseases. The antiarrhythmic drug amiodarone has demonstrated antifungal activity against a range of fungi, including C. neoformans. Here, considering the importance of calcium storage mediated by transporters on cryptococcal virulence, we evaluated the use of the calcium channel blocker amiodarone as an alternative therapy for cryptococcosis. C. neoformans displayed high sensitivity to amiodarone, which was also synergistic with fluconazole. Amiodarone treatment influenced some virulence factors, interrupting the calcium-calcineurin signaling pathway. Experiments with murine cryptococcosis models revealed that amiodarone treatment increased the fungal burden in the lungs, while its combination with fluconazole did not improve treatment compared to fluconazole alone. In addition, we have developed different innovative nanotechnological formulations, one of which combining two drugs with different mechanisms of action. Lipid-core nanocapsules (LNC) loaded with amiodarone (LNC_AMD), fluconazole (LNC_FLU) and both (LNC_AMD+FLU) were produced to achieve a better efficacy in vivo. In an intranasal model of treatment, all the LNC formulations had an antifungal effect. In an intraperitoneal treatment, LNC_AMD showed an enhanced anticryptococcal effect compared to the free drug, whereas LNC_FLU or LNC_AMD+FLU displayed no differences from the free drugs. In this way, nanotechnology using amiodarone formulations could be an effective therapy for cryptococcal infections.

Folic Acid-Doxorubicin-Double-Functionalized-Lipid-Core Nanocapsules: Synthesis, Chemical Structure Elucidation, and Cytotoxicity Evaluation on Ovarian (OVCAR-3) and Bladder (T24) Cancer Cell Lines

PURPOSE

Folic acid-doxorubicin-double-functionalized-lipid-core nanocapsules (LNC-CS-^L-Zn⁺²-DOX-FA) were prepared, characterized, and evaluated in vitro against ovarian and bladder cancer cell lines (OVCAR-3 and T24).

METHODS

LNC-CS-^L-Zn⁺²-DOX-FA was prepared by self-assembly and interfacial reactions, and characterized using liquid chromatography, particle sizing, transmission electron microscopy, and infrared spectroscopy. Cell viability and cellular uptake were studied using MTT assay and confocal microscopy.

RESULTS

The presence of lecithin allows the formation of nanocapsules with a lower tendency of agglomeration, narrower size distributions, and smaller diameters due to an increase in hydrogen bonds at the surface. LNC-^L-CS-Zn⁺²-DOX-FA, containing 98.00 ± 2.34 μg mL^-1 of DOX and 105.00 ± 2.05 μg mL^-1 of FA, had a mean diameter of 123 ± 4 nm and zeta potential of +12.0 ± 1.3 mV. After treatment with LNC-^L-CS-Zn⁺²-DOX-FA (15 μmol L^-1 of DOX), T24 cells had inhibition rates above 80% (24 h) and 90% (48 h), whereas OVCAR-3 cells showed inhibition rates of 68% (24 h) and 93% (48 h), showing higher cytotoxicity than DOX.HCl. The fluorescent-labeled formulation showed a higher capacity of internalization in OVCAR-3 compared to T24 cancer cells.

CONCLUSION

Lecithin favored the increase of hydrogen bonds at the surface, leading to a lower tendency of agglomeration for nanocapsules. LNC-CS-^L-Zn⁺²-DOX-FA is a promising therapeutic agent against tumor-overexpressing folate receptors.

Omeprazole nanoparticles suspension: Development of a stable liquid formulation with a view to pediatric administration

Omeprazole (OME) is often used to treat disorders associated with gastric hypersecretion in children but a liquid pediatric formulation of this medicine is not currently available. The aim of this study is to develop OME loaded nanoparticles with a view to the obtention of a liquid pharmaceutical dosage form. Eudragit® RS100 was selected as the skeleton material in the inner core and pH-sensitive Eudragit® L100-55 was used as the outer coating of the nanoparticles prepared by the nanoprecipitation method. Pharmacological activity was evaluated by induction of ethanol ulcers in mice. The OME nanoparticles exhibited mean diameters of 174 nm (±17), polydispersity index of 0.229 (±0.01), zeta potential values of -13 mV (±2.60) and encapsulation efficiency of 68.1%. The in vivo pharmacological assessment showed the ability of nanoparticles to protect mice stomach against ulcer formation. The prepared suspension of OME nanoparticles represents effective therapeutic strategy in a liquid pharmaceutical form with the possibility of pediatric administration.

Cytotoxic activity of poly-ɛ-caprolactone lipid-core nanocapsules loaded with lycopene-rich extract from red guava (Psidium guajava L.) on breast cancer cells

The aims of this study were to produce poly-ɛ-caprolactone lipid-core nanocapsules containing lycopene-rich extract from red guava (LEG), to characterize those nanoparticles and to evaluate their cytotoxic effects on human breast cancer cells. Lipid-core nanocapsules containing the extract (nanoLEG) were produced by the method of interfacial deposition of the preformed polymer. The nanoparticles were characterized by Dynamic Light Scattering (DLS), Polydispersity Index, Zeta Potential, pH, Encapsulation Efficiency, Nanoparticle Tracking Analysis (NTA), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). Cell viability was evaluated by the MTT dye reduction method in the human breast cancer MCF-7 cell line and inhibition of ROS and NF-κB was assayed in living human microglial cell line (HMC3) by time-lapse images microscopy. A hemolytic activity assay was carried out with sheep blood. Data showed that nanoparticles average size was around 200 nm, nanoparticles concentration/mL was around 0.1 µM, negative zeta potential, pH < 5.0 and spherical shape, with low variation during a long storage period (7 months) at 5 °C, indicating stability of the system and protection against lycopene degradation. The percentage of encapsulation varied from 95% to 98%. The nanoLEG particles significantly reduced the viability of the MCF-7 cells after 24 h (61.47%) and 72 h (55.96%) of exposure, even at the lowest concentration tested (6.25-200 μg/ml) and improved on the cytotoxicity of free LEG to MCF-7. NanoLEG inhibited LPS-induced NF-kB activation and ROS production in microglial cells. The particles did not affect the membrane integrity of sheep blood erythrocytes at the concentrations tested (6.25-200 μg/mL). Thus, the formulation of lipid-core nanocapsules with a polysorbate 80-coated poly-ɛ-caprolactone wall was efficiently applied to stabilize the lycopene-rich extract from red guava, generating a product with satisfactory physico-chemical and biological properties for application as health-promoting nanotechnology-based nutraceutical, emphasizing its potential to be used as a cancer treatment.

Chitosan-Coated Lipid-Core Nanocapsules Functionalized with Gold-III and Bevacizumab Induced In Vitro Cytotoxicity against C6 Cell Line and In Vivo Potent Antiangiogenic Activity

PURPOSE

Bevacizumab (BCZ) is a recombinant monoclonal antibody that inhibits the biological activity of the vascular endothelial growth factor, which has an important role in angiogenesis for tumoral growth and progression. In this way, our objective was to develop chitosan-coated lipid-core nanocapsules functionalized with BCZ by an organometallic complex using gold-III.

METHODS

The formulation was produced and characterized in relation to physicochemical characteristics. Furthermore, the antitumoral and antiangiogenic activities were evaluated against C6 glioma cell line and chicken embryo chorioallantoic membrane (CAM), respectively.

RESULTS

Final formulation showed nanometric size, narrow polydispersity, positive zeta potential and gold clusters size lower than 2 nm. BCZ in aqueous solution (0.01-0.10 μmol L^-1) did not show cytotoxic activity in vitro against C6 glioma cell line; although, MLNC-Au-BCZ showed cytotoxicity with a median inhibition concentration of 30 nmol L^-1 of BCZ. Moreover, MLNC-Au-BCZ demonstrated cellular internalization dependent on incubation time and BCZ concentration. BCZ solution did not induce significant apoptosis as compared to MLNC-Au-BCZ within 24 h of treatment. CAM assay evidenced potent antiangiogenic activity for MLNC-Au-BCZ, representing a decrease of 5.6 times in BCZ dose comparing to BCZ solution.

CONCLUSION

MLNC-Au-BCZ is a promising product for the treatment of solid tumors.

Assessment of unloaded polymeric nanocapsules with different coatings in female rats: Influence on toxicological and behavioral parameters

The unloaded polymeric nanocapsules (NCs) present incredible characteristics as drug carriers. However, the toxicity caused by NCs with different coatings is still a challenge for contemporary toxicology. Allied to this, preclinical studies are performed in males, disregarding possible gender-dependent toxicity. Thus, the aim of present study was to evaluate the influence of different NCs coatings on toxicological and behavioral parameters in female rats. The physicochemical characterization of NCs with different surface coatings: NC1 (Polysorbate 80), NC2 (PEG), NC3 (Eudragit®RS 100) and NC4 (Chitosan) were performed. Female rats were treated with saline, NC1, NC2, NC3 or NC4 daily for 14 days, p.o. After 24 h of last treatment, animals were submitted to behavioral tests. Only after behavioral tests, female rats were euthanized, organs were removed and weighted. After, histopathological, biochemical and oxidative stress analysis were performed. All NCs-coatings did not cause alterations in behavioral tests. For markers of hepatic, renal damage and lipid profile, the different coatings showed a low toxicity. NCs did not alter weight of organs and histopathological analysis. Also, all NCs-coatings did not modify redox balance in organs studied, only NC2 induced a increase of FRAP levels in intestine. This study demonstrated that the different NCs-coatings did not cause behavioral changes and showed a low toxicity in female rats.

Cationic and anionic unloaded polymeric nanocapsules: Toxicological evaluation in rats shows low toxicity

The experimental design aiming at evaluating the performance of drugs nanoencapsulated involves inclusion of a formulation without drug (unloaded). This formulation has sometimes presented per se effect. In this sense, we sought to evaluate the toxicity of unloaded polymeric nanocapsules (NCs) with different surfaces (cationic and anionic) in male Wistar rats in male Wistar rats. The physicochemical characterization of NCs with different surfaces: polysorbate 80 (P80), polyethylene glycol (PEG), eudragit ®RS 100 (EUD) and chitosan (CS) was performed. Rats were treated with unloaded NCs (P80, PEG, EUD and CS surfaces) daily for 14 days per oral route. 24 h of last treatment, animals were euthanized and organs were removed and weighted. After, biochemical determinations were performed. In general, NCs-surfaces did not cause alterations in body weight, weight of organs and histopathological analysis. PEG-surface NCs did not generate hepatotoxicity. In investigation of lipid profile, the surface with P80 changed TC and HDL-C levels. Besides that, all NCs did not alter oxidative stress markers in organs studied (TBARS and Reactive Species) and CS-surface presented antioxidant activity in kidney. This study demonstrated that NCs-surfaces depending on their physicochemical characteristics had low or no toxicity.

PEGylated meloxicam-loaded nanocapsules reverse in vitro damage on caspase activity and do not induce toxicity in cultured human lymphocytes and mice

Meloxicam is an anti-inflammatory drug that has a potential protective effect in many common diseases. However, this molecule is quickly eliminated from the body due to it short half-life. One way to overcome this problem is to incorporate meloxicam into lipid-core nanocapsules which may increase it anti-inflammatory effects. In view of this, the objective of this work was to evaluate the potential toxicity and safety of these novel nanomaterials both in vitro and in vivo. Here, we evaluated the effects of uncoated meloxicam-loaded nanocapsules (M-NC), uncoated and not loaded with meloxicam or blank (B-NC), PEGylated meloxicam-loaded lipid-core nanocapsules (M-NCPEG), blank PEGylated lipid-core nanocapsules (B-NCPEG) and free meloxicam (M-F) in vitro through the analysis of cell viability, caspase activity assays and gene expression of perforin and granzyme B. Meanwhile, the in vivo safety was assessed using C57BL/6 mice that received nanocapsules for seven days. Thus, no change in cell viability was observed after treatments. Furthermore, M-NC, M-NCPEG and M-F groups reversed the damage caused by H₂O₂ on caspase-1, 3 and 8 activities. Overall, in vivo results showed a safe profile of these nanocapsules including hematological, biochemical, histological and genotoxicity analysis. In conclusion, we observed that meloxicam nanocapsules present a safe profile to use in future studies with this experimental protocol and partially reverse in vitro damage caused by H₂O₂.

Renewable poly(δ-decalactone) based block copolymer micelles as drug delivery vehicle: in vitro and in vivo evaluation

Polymers from natural resources are attracting much attention in various fields including drug delivery as green alternatives to fossil fuel based polymers. In this quest, novel block copolymers based on renewable poly(δ-decalactone) (PDL) were evaluated for their drug delivery capabilities and compared with a fossil fuel based polymer i.e. methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-b-PCL). Using curcumin as a hydrophobic drug model, micelles of PDL block copolymers with different orientation i.e. AB (mPEG-b-PDL), ABA (PDL-b-PEG-b-PDL), ABC (mPEG-b-PDL-b-poly(pentadecalactone) and (mPEG-b-PCL) were prepared by nanoprecipitation method. The size, drug loading and curcumin stability studies results indicated that mPEG-b-PDL micelles was comparable to its counterpart mPEG-b-PCL micelles towards improved delivery of curcumin. Therefore, mixed micelles using these two copolymers were also evaluated to see any change in size, loading and drug release. Drug release studies proposed that sustained release can be obtained using poly(pentadecalactone) as crystalline core whereas rapid release can be achieved using amorphous PDL core. Further, mPEG-b-PDL micelles were found to be non-haemolytic, up to the concentration of 40 mg/mL. In vivo toxicity studies on rats advised low-toxic behaviour of these micelles up to 400 mg/kg dose, as evident by histopathological and biochemical analysis. In summary, it is anticipated that mPEG-b-PDL block copolymer micelles could serve as a renewable alternative for mPEG-b-PCL copolymers in drug delivery applications.

Lipid-core nanocapsules increase the oral efficacy of quercetin in cutaneous leishmaniasis

New oral treatments are needed for all forms of leishmaniasis. Here, the improved oral efficacy of quercetin (Qc) and its penta-acetylated derivative (PQc) was evaluated in cutaneous leishmaniasis after encapsulation in lipid-core nanocapsules (LNCs) of poly(ε-caprolactone). Leishmania amazonensis-infected BALB/c mice were given 51 daily oral doses of free drugs (16 mg kg-1) or LNC-loaded drugs (0·4 mg kg-1). While treatment with free Qc reduced the lesion sizes and parasite loads by 38 and 71%, respectively, LNC-Qc produced 64 and 91% reduction, respectively. The antileishmanial efficacy of PQc was similar but not as potently improved by encapsulation as Qc. None of the treatments increased aspartate aminotransferase, alanine aminotransferase or creatinine serum levels. These findings indicate that when encapsulated in LNC, Qc and, to a lesser extent, PQc can safely produce an enhanced antileishmanial effect even at a 40-fold lower dose, with implications for the development of a new oral drug for cutaneous leishmaniasis.

Safety assessment of nanopesticides using the roundworm Caenorhabditis elegans

The extensive use of pesticides is causing environmental pollution, affecting animal organisms in different habitats and also leading human health at risk. In this study, we present as an alternative the use of nanoparticles loaded with pesticides and report their toxicological assessment to a soil organism, Caenorhabditis elegans. Three nanoparticle formulations were analyzed: solid lipid nanoparticles loaded or not with atrazine and simazine, SLN; polymeric nanoparticles, NC_PCL loaded with atrazine; and chitosan/tripolyphosphate, CS/TPP, loaded or not with paraquat. All formulations, loaded or not with pesticides, increased lethality in a dose- dependent manner with similar LC50. Both loaded and unloaded NC_PCL were the most toxic formulations to developmental rate, significantly reducing worms length, even at low concentrations. In contrast, both CS/TPP nanoparticles were the least toxic, not affecting reproduction and body length at higher concentrations, probably due to the biocompatibility of chitosan. The physico-chemical characterization of nanoparticles after incubation in saline solution (used in exposure of organisms) has shown that these colloidal systems are stable and remain with the same initial characteristics, even in the presence of saline environment. Notably, our results indicate that the observed effects were caused by the nanoparticles per se. These results suggest that the development of nanoparticles aiming agriculture applications needs more studies in order to optimize the composition and then reduce their toxicity to non-target organisms.

Production of Isotonic, Sterile, and Kinetically Stable Lipid-Core Nanocapsules for Injectable Administration

Lipid-core nanocapsules (LNC) were designed and prepared as a colloidal system for drug targeting to improve the stability of drugs and allow their controlled release. For parenteral administration, it is necessary to ensure formulation sterility. However, sterilization of nanotechnological devices using an appropriate technique that keeps the supramolecular structure intact remains a challenge. This work aimed to evaluate the effect of autoclaving on the physicochemical characteristics of LNC. Formulations were prepared by the self-assembling method, followed by isotonization and sterilization at varying times and temperatures. The isotonicity was confirmed by determining the freezing temperature, which was -0.51°C. The formulation was broadly characterized, and the diameter of the particles was determined utilizing complementary methods. To evaluate the chemical stability of poly(ε-caprolactone), its molecular weight was determined by size exclusion chromatography. The physicochemical characteristics (average diameter, viscosity, and physical stability) of the formulation were similar before and after adding glycerol and conducting the sterilization at the highest temperature (134°C) and the shorter exposure time (10 min). After autoclaving, the sterility test was performed and showed no detectable microbial growth. Multiple light scattering demonstrated that the formulations were kinetically stable, and the mean diameter was constant for 6 months, corroborating this result. The polymer was chemically stable in the sterilized formulation. Isotonic and sterile LNC aqueous suspensions were produced using glycerol and autoclaving. Briefly, the results open an opportunity to produce an isotonic and sterile LNC aqueous dispersion applicable as nanomedicine for intravenous administration in clinical trials.

Effect of quinine-loaded polysorbate-coated nanocapsules on male and female reproductive systems of rats

Quinine is an antimalarial drug; however, its use is limited by its narrow therapeutic index and elevated side effects. The nanosystems are promising delivery vehicles of antimalarial drugs, enhancing their therapeutic potential. This study aimed to compare the toxicity of quinine and quinine loaded nanocapsules (Q-NC) on the reproductive system of male and female rats. The animals received quinine or Q-NC orally at the same dose of 25 mg kg^-1 for 7 days (real period of quinine therapy in humans). 24 hours after the last administration, the rats were euthanized and the ovarian and testicular tissues were removed for histological and biochemical analyses. The groups treated with quinine presented ovarian and testicular damage, evidenced by the increase of reactive species and malondialdehyde levels, the decrease of 17β-hydroxysteroid dehydrogenase activity and alterations on total antioxidant capacity. The females presented a decrease of follicular viability and the males presented a decrease of spermatozoa membrane integrity, as well as moderated histological alterations on testis after the exposure to quinine. After the treatment with Q-NC, the males presented decreased reactive species levels and total antioxidant capacity at control levels, as well as spermatozoa with 100% of membrane integrity. The females treated with Q-NC presented reactive species levels, total antioxidant capacity, 17β-hydroxysteroid dehydrogenase activity and follicular viability at control levels, and decreased malondialdehyde levels when compared to quinine, but not at control levels. This study demonstrated that loading polymeric nanocapsules with quinine decreased the deleterious effects induced by quinine on ovaries and partially on testicles.

Development and characterization of methoxy poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL) micelles as vehicles for the solubilization and delivery of tacrolimus

Tacrolimus is a potent immunosuppressant; however, it suffers from several problems such as poor water solubility (4-12 μg/mL), low and variable oral bioavailability in patients, and narrow therapeutic window that could not be solved by the currently available i.v. formulation (Prograf®). Moreover, Prograf® contains HCO-60 (PEGylated castor oil) as a surfactant, which is reported to cause several side effects including hypersensitivity reactions. Therefore, the aim of the present study was to investigate the potential of PEO-b-PCL polymeric micelles as alternative vehicles for the solubilization and delivery of tacrolimus. Four PEO-b-PCL block copolymers, with different molecular weights of PCL, were synthesized by ring opening polymerization of ε-caprolactone using methoxy polyethylene oxide (5,000 g mol^-1) as initiator and stannous octoate as catalyst. Synthesized copolymers were characterized for their average molecular weights and polydispersity index by ¹H NMR and gel permeation chromatography (GPC), respectively. Drug-free micelles of PEO-b-PCL were prepared through a co-solvent evaporation method using acetone as the organic co-solvent. Tacrolimus-loaded micelles were prepared using the same method with different initial amounts of drug. Prepared micelles were characterized for their mean diameter size and polydispersity of the micellar population by dynamic light scattering, and an HPLC assay was used to determine the encapsulation efficiency of tacrolimus. The average molecular weights of the synthesized copolymers were in the range of 8,400-28,000 with narrow distributions (PDI = 1.06-1.11). The copolymers were designated according to the degree of polymerization of ε-caprolactone, namely PEO₁₁₄-b-PCL₃₀, PEO₁₁₄-b-PCL₆₀, PEO₁₁₄-b-PCL₁₂₀, and PEO₁₁₄-b-PCL₂₀₀. All the prepared micelles were having diameters sizes less than 100 nm with narrow distributions. The highest drug solubilization was achieved with PEO₁₁₄-b-PCL₁₂₀, where the aqueous solubility of tacrolimus exceeded 300 μg/mL. Our results show a potential for PEO-b-PCL micelles as solubilizing vehicles for the delivery of tacrolimus.

Novel therapeutic mechanisms determine the effectiveness of lipid-core nanocapsules on melanoma models

Melanoma is a severe metastatic skin cancer with poor prognosis and no effective treatment. Therefore, novel therapeutic approaches using nanotechnology have been proposed to improve therapeutic effectiveness. Lipid-core nanocapsules (LNCs), prepared with poly(ε-caprolactone), capric/caprylic triglyceride, and sorbitan monostearate and stabilized by polysorbate 80, are efficient as drug delivery systems. Here, we investigated the effects of acetyleugenol-loaded LNC (AcE-LNC) on human SK-Mel-28 melanoma cells and its therapeutic efficacies on melanoma induced by B16F10 in C57B6 mice. LNC and AcE-LNC had z-average diameters and zeta potential close to 210 nm and -10.0 mV, respectively. CytoViva(®) microscopy images showed that LNC and AcE-LNC penetrated into SK-Mel-28 cells, and remained in the cytoplasm. AcE-LNC in vitro treatment (18-90×10(9) particles/mL; 1 hour) induced late apoptosis and necrosis; LNC and AcE-LNC (3-18×10(9) particles/mL; 48 hours) treatments reduced cell proliferation and delayed the cell cycle. Elevated levels of nitric oxide were found in supernatant of LNC and AcE-LNC, which were not dependent on nitric oxide synthase expressions. Daily intraperitoneal or oral treatment (days 3-10 after tumor injection) with LNC or AcE-LNC (1×10(12) particles/day), but not with AcE (50 mg/kg/day, same dose as AcE-LNC), reduced the volume of the tumor; nevertheless, intraperitoneal treatment caused toxicity. Oral LNC treatment was more efficient than AcE-LNC treatment. Moreover, oral treatment with nonencapsulated capric/caprylic triglyceride did not inhibit tumor development, implying that nanocapsule supramolecular structure is important to the therapeutic effects. Together, data herein presented highlight the relevance of the supramolecular structure of LNCs to toxicity on SK-Mel-28 cells and to the therapeutic efficacy on melanoma development in mice, conferring novel therapeutic mechanisms to LNC further than a drug delivery system.

Evaluation of potential acute cardiotoxicity of biodegradable nanocapsules in rats by intravenous administration

Nanotoxicology aims to study the safety of nanomaterials, especially towards human exposure. Biodegradable polymeric nanocapsules have been indicated as potential drug carriers applicable for treating several pathologies. Thus, the objective of this study was to evaluate the potential cardiotoxicity of biodegradable lipid-core nanocapsules (LNC) containing poly(ε-caprolactone). Nanocapsules were characterized and the acute toxicity evaluation was conducted in Wistar rats. Two control groups (saline and tween/glycerol) were utilized, and three treated groups were chosen for low, intermediate and high doses: 28.7 × 1012 (LNC-1), 57.5 × 1012 (LNC-2) and 115 × 1012 (LNC-3), expressed as number of nanocapsules per milliliter per kg. Blood pressure measurements were performed in non-anesthetized animals by caudal plethysmography. The electrocardiographic (ECG) and echocardiographic analyses were carried out after anesthesia by isoflurane at two points, prior to treatment and after 14 days. Blood was collected 24 hours and 14 days after treatment. Biochemical and histopathological analyses were performed. During the evaluation period, no deaths, weight loss or clinical signs were observed. Post-treatment systolic pressures (24 h and 14 days) were significantly increased in comparison to pre-treatment in both control groups and treated groups, which is suggested to be as a possible consequence of the infused volume. Serum sodium, potassium, aspartate aminotransferase and alkaline phosphatase, as well as, hematological parameters were within reference values established for rats. ECG showed no indications of cardiotoxicity. Despite the echocardiograms, no alterations in the ejection fraction were found as indicators of cardiotoxicity. Cardiac histopathology also demonstrated no alterations. Therefore, the present results on acute evaluation after i.v. administration, by slow infusion, showed potential safety since no cardiotoxic effects by ECG, echocardiographic, arterial pressure, biochemical and histopathological analyses were found.

Methotrexate-loaded lipid-core nanocapsules are highly effective in the control of inflammation in synovial cells and a chronic arthritis model

BACKGROUND

Rheumatoid arthritis (RA) is the most common autoimmune disease in the word, affecting 1% of the population. Long-term prognosis in RA was greatly improved following the introduction of highly effective medications such as methotrexate (MTX). Despite the importance of this drug in RA, 8%-16% of patients must discontinue the treatment because of adverse effects. Last decade, we developed a promising new nanocarrier as a drug-delivery system, lipid-core nanocapsules.

OBJECTIVE

The aim of the investigation reported here was to evaluate if methotrexate-loaded lipid-core nanocapsules (MTX-LNC) reduce proinflammatory and T-cell-derived cytokines in activated mononuclear cells derived from RA patients and even in functional MTX-resistant conditions. We also aimed to find out if MTX-LNC would reduce inflammation in experimentally inflammatory arthritis at lower doses than MTX solution.

METHODS

Formulations were prepared by self-assembling methodology. The adjuvant arthritis was induced in Lewis rats (AIA) and the effect on edema formation, TNF-α levels, and interleukin-1 beta levels after treatment was evaluated. Mononuclear cells obtained from the synovial fluid of RA patients during articular infiltration procedures were treated with MTX solution and MTX-LNC. For in vitro experiments, the same dose of MTX was used in comparing MTX and MTX-LNC, while the dose of MTX in the MTX-LNC was 75% lower than the drug in solution in in vivo experiments.

RESULTS

Formulations presented nanometric and unimodal size distribution profiles, with D[4.3] of 175±17 nm and span of 1.6±0.2. Experimental results showed that MTX-LNC had the same effect as MTX on arthritis inhibition on day 28 of the experiment (P<0.0001); however, this effect was achieved earlier, on day 21 (P<0.0001), by MTX-LNC, and this formulation had reduced both TNF-α (P=0.001) and IL-1α (P=0.0002) serum levels by the last day of the experiment. Further, the MTX-LNC were more effective at reducing the cytokine production from mononuclear synovial cells than MTX.

CONCLUSION

The MTX-LNC were better than the MTX solution at reducing proinflammatory cytokines and T-cell-derived cytokines such as interferon-gamma and interleukin-17A. This result, combined with the reduction in the dose required for therapy, shows that MTX-LNC are a very promising system for the treatment of RA.

Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-core nanocapsules on paraquat damage

Caenorhabditis elegans is an alternative in vivo model that is being successfully used to assess the pharmacological and toxic effects of drugs. The exponential growth of nanotechnology requires the use of alternative in vivo models to assess the toxic effects of theses nanomaterials. The use of polymeric nanocapsules has shown promising results for drug delivery. Moreover, these formulations have not been used in cases of intoxication, such as in treatment of paraquat (PQ) poisoning. Thus, the use of drugs with properties improved by nanotechnology is a promising approach to overcome the toxic effects of PQ. This research aimed to evaluate the absorption of rhodamine B-labeled melatonin (Mel)-loaded lipid-core nanocapsules (LNC) by C. elegans, the application of this model in nanotoxicology, and the protection of Mel-LNC against PQ damage. The formulations were prepared by self-assembly and characterized by particle sizing, zeta potential, drug content, and encapsulation efficiency. The results demonstrated that the formulations had narrow size distributions. Rhodamine B-labeled Mel-LNC were orally absorbed and distributed in the worms. The toxicity assessment of LNC showed a lethal dose 50% near the highest dose tested, indicating low toxicity of the nanocapsules. Moreover, pretreatment with Mel-LNC significantly increased the survival rate, reduced the reactive oxygen species, and maintained the development in C. elegans exposed to PQ compared to those worms that were either untreated or pretreated with free Mel. These results demonstrated for the first time the uptake and distribution of Mel-LNC by a nematode, and indicate that while LNC is not toxic, Mel-LNC prevents the effects of PQ poisoning. Thus, C. elegans may be an interesting alternative model to test the nanocapsules toxicity and efficacy.

Do poly(epsilon-caprolactone) lipid-core nanocapsules induce oxidative or inflammatory damage after in vivo subchronic treatment?

Among the toxicity mechanisms linked to nanoparticles (NPs), oxidative stress (OS) and inflammation are, in general, presumed to mediate their toxicological responses.

Methotrexate diethyl ester-loaded lipid-core nanocapsules in aqueous solution increased antineoplastic effects in resistant breast cancer cell line

Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX) is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt)₂]) and MTX(OEt)₂-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt)₂ solution and MTX(OEt)₂-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231 cells, MTX(OEt)₂-loaded lipid-core nanocapsules were significantly more efficient in inducing apoptosis than the solution of the free drug. S-phase cell cycle arrest was induced only by MTX(OEt)₂ solution. The drug nanoencapsulation improved apoptosis induction for the cell line that presents MTX resistance by lack of transport receptors.

Free and nanoencapsulated curcumin suppress β-amyloid-induced cognitive impairments in rats: involvement of BDNF and Akt/GSK-3β signaling pathway

Alzheimer's disease (AD), a neurodegenerative disorder exhibiting progressive loss of memory and cognitive functions, is characterized by the presence of neuritic plaques composed of neurofibrillary tangles and β-amyloid (Aβ) peptide. Drug delivery to the brain still remains highly challenging for the treatment of AD. Several studies have been shown that curcumin is associated with anti-amyloidogenic properties, but therapeutic application of its beneficial effects is limited. Here we investigated possible mechanisms involved in curcumin protection against Aβ(1-42)-induced cognitive impairment and, due to its poor bioavailability, we developed curcumin-loaded lipid-core nanocapsules in an attempt to improve the neuroprotective effect of this polyphenol. Animals received a single intracerebroventricular injection of Aβ(1-42) and they were administered either free curcumin or curcumin-loaded lipid-core nanocapsules (Cur-LNC) intraperitoneally for 10days. Aβ(1-42)-infused animals showed a significant impairment on learning-memory ability, which was paralleled by a significant decrease in hippocampal synaptophysin levels. Furthermore, animals exhibited activated astrocytes and microglial cells, as well as disturbance in BDNF expression and Akt/GSK-3β signaling pathway, beyond tau hyperphosphorylation. Our findings demonstrate that administration of curcumin was effective in preventing behavioral impairments, neuroinflammation, tau hyperphosphorylation as well as cell signaling disturbances triggered by Aβ in vivo. Of high interest, Cur-LNC in a dose 20-fold lower presented similar neuroprotective results compared to the effective dose of free curcumin. Considered overall, the data suggest that curcumin is a potential therapeutic agent for neurocognition and nanoencapsulation of curcumin in LNC might constitute a promising therapeutic alternative in the treatment of neurodegenerative diseases such as AD.

In vivo toxicological evaluation of polymeric nanocapsules after intradermal administration

Polymeric nanocarriers have shown great promise as delivery systems. An alternative strategy has been to explore new delivery routes, such as intradermal (i.d.), that can be used for vaccines and patch-based drug delivery. Despite their many advantages, there are few toxicity studies, especially in vivo. We report a safety assessment of biodegradable poly(ɛ-caprolactone) lipid-core nanocapsules (LNC) with a mean size of 245±10nm following single and repeated intradermal injections to Wistar rats. Suspensions were prepared by interfacial deposition of polymer. The animals (n=6/group) received a single-dose of saline solution (1.2ml/kg) or LNC (7.2×10(12)LNC/kg), or repeated-doses of two controls, saline solution or Tween 80 (0.9ml/kg), or three different concentrations of LNC (1.8, 3.6, and 5.4×10(12)LNC/kg) for 28 consecutive days. Clinical and physiological signs and mortality were observed. Samples of urine, blood, and tissue were used to perform toxicological evaluation. There were no clinical signs of toxicity or mortality, but there was a slight decrease in the relative body weights in the Tween 80-treated group (p<0.01) after repeated administration. No histopathological alterations were observed in tissues or significant changes in blood and urinary biomarkers for tissue damage. Mild alterations in white blood cells count with increases in granulocytes in the Tween-80 group (p<0.05) were found. Genotoxicity was evaluated through the comet assay, and no statistical difference was observed among the groups. Therefore, we conclude that, under the conditions of these experiments, biodegradable LNC did not present appreciable toxicity after 28 consecutive days of intradermal administration and is promising for its future application in vaccines and patch-based devices for enhancing the delivery of drugs.