Surface-coated PLA nanoparticles loaded with temozolomide for improved brain deposition and potential treatment of gliomas: development,characterization and in vivo studies

Hydrophobicity of PLA nanoparticles makes them a good substrate for macrophageal and reticulo-endothelial system uptake. Long-circulating properties can be imparted to these particles by coating them with hydrophilic stabilizers. Surface-modified PLA nanoparticles loaded with anti-cancer agent temozolomide were fabricated by solvent evaporation method and coated with surface modifiers. Selection of the surface modifier was based upon uptake of nanoparticles by K9 cells (liver cells). The particles were prepared and characterized for various physicochemical properties using transmission electron microscopy, differential scanning calorimetry, powder X-ray diffraction and in vitro dissolution studies. In vitro BBB permeation studies were performed using the co-culture model developed by using Madin–Darby canine kidney and C6 glioma cells as endothelial and glial cells, respectively. In vitro C6 glioma cell cytotoxicity, cellular proliferation, cellular migration and cellular uptake studies due to developed nanoparticles was assessed. In vivo studies such as pharmacokinetics, qualitative and quantitative biodistribution studies were performed for the developed nanoparticles. Drug-loaded nanoparticles with entrapment efficiency of 50% were developed. PEG-1000 and polysorbate-80 coated nanoparticles were least taken up by the liver cells. Characterization of the nanoparticles revealed formation of spherical shape nanoparticles, with no drug and excipient interaction. In vivo pharmacokinetics of developed nanoparticles depicted enhancement of half-life, area under the curve and mean residence time of the drug. Qualitative and quantitative biodistribution studies confirmed enhanced permeation of the drug into the brain upon loading into nanoparticles with less deposition in the highly perfused organs like lung, liver, spleen, heart and kidney.     

Translocation and effects of gold nanoparticles after inhalation exposure in rats

This study was carried out to test the hypothesis that nanogold particles can accumulate in the olfactory bulb, and translocate from the lung to other organs after inhalation exposure. Gold nanoparticles were aerosolized and introduced through an exposure chamber. The number concentration of airborne nano-sized particles was 2×10⁶ #NSPs/cm³ with >75% of particulates between 30 and 110 nm. Exposure for 5 days resulted in significant increase of Au in the lung and olfactory bulb as detected by ICP-MS, but after 15 days, significant accumulation of gold was detected in the lung, esophagus, tongue, kidney, aorta, spleen, septum, heart and blood. Microarray analysis showed downregulation of many genes related to muscle in the nanogold-exposed lung. Lipidomic analysis of the lung showed a specific decrease in phosphatidylserine 36:1 species. We conclude that nanogold is able to translocate from the lung to other organs with time, and causes significant effects in exposed tissues.     

Airway irritation,inflammation, and toxicity in mice following inhalation of metal oxide nanoparticles

Metal oxide nanoparticles are used in a broad range of industrial processes and workers may be exposed to aerosols of the particles both during production and handling. Despite the widespread use of these particles, relatively few studies have been performed to investigate the toxicological effects in the airways following inhalation. In the present study, the acute (24?h) and persistent (13 weeks) effects in the airways after a single exposure to metal oxide nanoparticles were studied using a murine inhalation model. Mice were exposed 60?min to aerosols of either ZnO, TiO₂, Al₂O₃ or CeO₂ and the deposited doses in the upper and lower respiratory tracts were calculated. Endpoints were acute airway irritation, pulmonary inflammation based on analyses of bronchoalveolar lavage (BAL) cell composition, DNA damage assessed by the comet assay and pulmonary toxicity assessed by protein level in BAL fluid and histology. All studied particles reduced the tidal volume in a concentration-dependent manner accompanied with an increase in the respiratory rate. In addition, ZnO and TiO₂ induced nasal irritation. BAL cell analyses revealed both neutrophilic and lymphocytic inflammation 24-h post-exposure to all particles except TiO₂. The ranking of potency regarding induction of acute lung inflammation was Al₂O₃ = TiO_2?<_?CeO₂ ? ZnO. Exposure to CeO₂ gave rise to a more persistent inflammation; both neutrophilic and lymphocytic inflammation was seen 13 weeks after exposure. As the only particles, ZnO caused a significant toxic effect in the airways while TiO₂ gave rise to DNA-strand break as shown by the comet assay.     

Antitumor activity of electrospun polylactide nanofibers loaded with 5-fluorouracil and oxaliplatin against colorectal cancer

The purpose of this study was to evaluate both in vitro and in vivo anticancer activities against colorectal cancer (CRC) of electrospun polylactide (PLA) nanofibers loaded with 5-fluorouracil (5-Flu) and oxaliplatin. For in vitro evaluation, human CRC HCT8 cells were directly exposed to the drug-loaded fiber mats, followed with MTT and flow cytometry (FCM) assay. For in vivo evaluation, the drug-loaded fiber mats were locally implanted into mouse colorectal CT26 tumor-bearing mice, followed with histological analysis and detection of survival rate. The results showed that the drug-loaded fiber mats was similar to that of the combination of free 5-Flu and oxaliplatin in vitro cytotoxicity but was much superior to intravenous injection of free drug in vivo anticancer activities, presenting with suppressed tumor growth rate and prolonged survival time of mice. In conclusion, anticancer activities of 5-Flu and oxaliplatin against CRC can be significantly improved by using PLA electrospun nanofibers as local drug delivery system.     

Physiological uptake and retention of radiolabeled resveratrol loaded gold nanoparticles (99mTc-Res-AuNP) in colon cancer tissue

When tagged with a suitable radionuclide, the cancer targeting properties of trans-resveratrol could be utilized to locate cancerous sites in the body using radionuclide imaging technique. However, the polyphenol due to its rapid and extensive metabolism exhibits low bioavailability in vivo. The study was designed to enhance the cancer targeting efficacy of radiolabeled resveratrol using nano-based technology. Technetium-99m labeled resveratrol loaded gold nanoparticles (Res-AuNP) were synthesized, characterized and evaluated for their cancer targeting efficacy in HT29 colon cancer cells and in animal cancer model. Results of various investigations were compared to corresponding results obtained for ^99mTc-AuNP and ^99mTc-resveratrol. Cancer cell internalization observed for ^99mTc-Res-AuNP was significantly higher than that of ^99mTc-AuNP and ^99mTc-resveratrol. Also, a gradual rise in target to nontarget uptake with time was observed following i.v. administration of ^99mTc-Res-AuNP to colon tumor bearing rats, demonstrating better in vivo targeting of colon adenocarcinoma with ^99mTc-Res-AuNP when compared to ^99mTc-resveratrol.     

Mechanisms of acute inhalation effects of (+) and (-)-alpha-pinene in BALB/c mice

The effects of (+)-alpha-pinene and (-)-alpha-pinene vapours were studied for respiratory effects in BALB/c mice. The (+) enantiomer showed persistent sensory irritation effect on the upper respiratory tract during exposures in the range of 100 to 3691 ppm. The threshold concentration for this effect was calculated to be about 70 ppm, which is close to the no-effect level of about 40 ppm in humans. A significant airflow limitation occurred from exposure concentrations of 200 ppm and higher. No irritating effect was observed at the alveolar level and no central nervous system effect was obvious. In the exposure range from 218 to 5213 ppm, the (-) enantiomer produced only a short-lasting sensory irritation effect during the first 10 min. of exposure and only at concentrations above 2900 ppm. The tidal volume decreased significantly from approximately 400 ppm, but it was first conspicuous above 1000 ppm. Airflow limitation appeared consistently from approximately 2000 ppm. The (-) enantiomer also induced anesthesia/and or pulmonary irritation as well as sudden death at concentrations above 2600 ppm. Overall, the enantiomers showed different time-dependent and stereoselective effects. The lower sensory irritation effect of the (-) enantiomer probably being due to less of the molecule being adsorbed to a sensory irritant receptor.     

Antitumor activity of doxorubicin encapsulated in hexadecylphosphocholine (HePC) liposomes against human xenografts on Scid mice

Doxorubicin was encapsulated into liposomes composed of hexadecylphosphocholine:egg yolk phosphatidylcholine:stearylamine (HePC.EPC:SA) 10:10.0.1 (molar ratio) (1) and EPC:SA 10:0.1 (molar ratio) (2). Liposomal formulations 1 and 2, as well as free doxorubicin and free HePC, were tested in vitro against HCT116 human colon cancer cell lines and peripheral blood mononuclear cells (PBMCs) obtained from healthy donors, using the sulphorodamine B assay. The activity of doxorubicin was retained or slightly improved when entrapped into liposomes 1 and 2, while liposomal formulation 1 incorporating doxorubicin was found to be less toxic against normal cells. The liposomes were tested in vivo against human colon cancer xenografts in scid mice. The antitumor activities of liposomes 1 and 2 were statistically similar to that of free doxorubicin, but their toxicity was significantly lower. Based on these results, the combination of HePC and doxorubicin in one liposomal formulation may be justified for further evaluation.     

Interaction of gold nanoparticles and nickel(II) sulfate affects dendritic cell maturation

Despite many investigations have focused on the pristine toxicity of gold nanoparticles (GNPs), little is known about the outcome of co-exposure and interaction of GNPs with heavy metals which can possibly detoxify or potentiate them. Here, the combined exposure of nickel (II) sulfate (NiSO₄) and GNPs on the maturation response of dendritic cells (DCs) was explored. Exposure to GNPs or NiSO₄ separately induced cell activation. When cells were exposed to a mixture of both, however, the observed cell activation pattern indicated a competitive rather than an additive effect of both inducers with levels similar to those induced by NiSO₄ alone. Quantification of the GNP uptake by DCs demonstrated a significant decrease in intracellular gold content during co-incubation with NiSO₄. An extensive physiochemical characterization was performed to determine the interaction between GNPs and NiSO₄ in the complex physiological media using nanoparticle tracking analyses, disc centrifugation, UV–visible spectroscopy, ICP-MS analyses, zeta potential measurements, electron microscopy, and proteomics. Although GNPs and NiSO₄ did not directly interact with each other, the presence of NiSO₄ in the physiological media resulted in changes in GNPs' charge and their associated protein corona (content and composition), which may contribute to a decreased cellular uptake of GNPs and sustaining the nickel-induced DC maturation. The presented results provide new insights in the interaction of heavy metals and NPs in complex physiological media. Moreover, this study highlights the necessity of mixture toxicology, since these combined exposures are highly relevant for human subjection to NPs and risk assessment of nanomaterials.     

Antitumor activity of 2-amino-4,4alpha-dihydro-4alpha, 7-dimethyl-3H-phenoxazine-3-one against Meth A tumor transplanted into BALB/c mice

We examined the in vivo effect of 2-amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3- one (Phx) on Meth A carcinoma cells transplanted into BALB/c mice, in terms of both antitumor activity and side effects. Phx, which was synthesized by the reaction of 2-amino-5-methylphenol with bovine hemolysates, was administered i.p. at doses of 1 and 5 mg/kg to BALB/c mice transplanted with Meth A tumor cells. Phx exerted a strong antitumor activity to Meth A tumor growing in the mice as 5-fluorouracil (5-FU) did. The antitumor activity of Phx at the dose of 5 mg/kg was comparable to that of 5-FU at the dose of 7.8 mg/kg. In contrast, unlike 5-FU, Phx did not cause leukopenia while showing a strong antitumor activity. The compound also produced little changes in body weight and no wasting of mice developed. These results show that Phx has strong anti-tumor activity, but exerts lower side effects and suggest that Phx is available for therapeutic purposes in the future.     

Enhancing the efficiency of bortezomib conjugated to pegylated gold nanoparticles: an in vitro study on human pancreatic cancer cells and adenocarcinoma human lung alveolar basal epithelial cells

ABSTRACT

Objectives: Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells.

Methods: Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines.

Results: We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h’ incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC₅₀ value of free BTZ is respectively 1.5 and 4.3 times higher than the IC₅₀ value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC₅₀ value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs.

Conclusions: Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).     

5-氟尿嘧啶-N-琥珀酰壳聚糖纳米粒在荷瘤小鼠体内组织分布分析方法

目的:建立5-氟尿嘧啶-N-琥珀酰壳聚糖纳米粒(5-FU-Suc-Chi/NPs)在荷瘤小鼠血浆和组织中高效液相色谱(HPLC)分析方法。方法:生物样品经甲醇沉淀蛋白质并提取药物,采用HPLC法测定药物含量。色谱柱:Hypersil ODS C18(4.6mm×200mm,5μm);流动相:水-甲醇(99∶1)以磷酸调pH值6.2;流速:0.8mL.min-1;紫外检测波长:266nm;柱温:室温;进样量:20μL;内标:利巴韦林。结果:该方法线性范围为0.1~10mg.L-1,线性关系良好(r2=0.993 2~0.997 9),方法回收率、日内和日间精密度的RSD均小于15%。结论:该分析方法灵敏性、准确性较高,适用于5-FU-Suc-Chi/NPs荷瘤小鼠肿瘤靶向性及药动学研究。     

Increased in vitro leishmanicidal activity of octyl gallate loaded poly(methyl methacrylate) nanoparticles

The current paucity of effective and affordable drugs for the treatment of leishmaniasis renders the search for new therapeutic alternatives a priority. Gallic acid-related compounds display anti-parasitic activities and their incorporation into drug carrier systems, such as polymeric nanoparticles may be a viable alternative for leishmaniasis treatment. Therefore, this study focused on the synthesis and characterization of octyl gallate (G8) loaded poly(methyl methacrylate) (PMMA) nanoparticles via miniemulsion polymerization in order to increase the leishmanicidal activity of this compound. G8 loaded PMMA nanoparticles presented a spherical morphology with a mean size of 108?nm, a negatively charged surface (?33?±?5?mV) and high encapsulation efficiency (83% ± 5). Fourier-transform infrared spectroscopy and X-ray diffraction analysis confirmed that G8 was encapsulated in PMMA nanoparticles and presented a biphasic release profile. The G8 loaded PMMA nanoparticles did not present cytotoxic effect on human red blood cells. G8 loaded PMMA nanoparticles displayed a leishmanicidal activity almost three times higher than free G8 while the cytotoxic activity against human THP-1 cells remained unchanged.     

A further review of inhalation studies with cigarette smoke and lung cancer in experimental animals,including transgenic mice

Context: The lack of an effective animal model for pulmonary carcinogenesis in smokers is a continuing problem for researchers trying to design Potentially Reduced Risk Products for those smokers who are either unwilling or unable to quit smoking. The major failing of inhalation assays with cigarette smoke in laboratory animals is that these assays produce only small percentages of animals with pulmonary tumors (e.g. adenomas, with the occasional adenocarcinoma), as opposed to the highly invasive carcinomas (e.g. small cell and squamous cell) seen in smokers.

Objective: To update previous reviews on animal models, and to add different types of transgenic (Tg) mice to the review.

Methods: Reviews were made of articles retrieved from PubMed and elsewhere.

Results: The addition of Tg mice to the arsenal of tests used for the evaluation of the carcinogenic potential of cigarettes did not result in any better understanding of the inability of such testing to reflect the epidemiological evidence for lung cancer in smokers.

Conclusion: As in previous reviews on the subject, the best assay providing support for the epidemiology data is still the 5-month whole-body exposure of male A/J mice to a combination of mainstream/sidestream smoke, followed by a 4-month recovery.     

Cellular uptake and toxicity of gold nanoparticles in prostate cancer cells: a comparative study of rods and spheres

Using a series of gold nanoparticles with incremental increase in dimensions but varying geometries (spherical vs rods) we have evaluated the influence of shape, size, surface properties and concentration on cellular uptake, adsorption of proteins and toxicity in a human prostate cancer cell line (PC‐3). In the range of 30–90 nm diameter studied, spherical particles of 50 nm in diameter without polyethylene glycol (PEG) had the highest uptake. Surface attachment of PEG reduced cellular uptake. PEGylated gold nanorods had a net positive charge compared with their spherical counterparts and particle geometry influenced cellular uptake. In the absence of serum proteins the uptake of plain spherical GNPs increased. These studies pave the way for the tailoring of gold nanoparticles for targeted tumor therapy applications. Copyright © 2009 John Wiley & Sons, Ltd.     

Biokinetics of ultrafine gold nanoparticles (AuNPs) relating to redistribution and urinary excretion: a long-term in vivo study

Gold nanoparticles (AuNPs) of ultrafine size have drawn attention for their use in drug delivery systems. Tissue toxicity may be an issue when AuNPs are used for such applications. We investigated the long-term biokinetics (90 d), redistribution, and urinary excretion of three different-sized (2?±?0.5?nm, 5?±?1?nm, and 10?±?2?nm) AuNPs after a single intravenous (i.v.) administration of 1250?µg/kg dose in mice. ICP-AES analysis of lungs, liver, spleen, heart, kidney, brain, blood, and urine revealed highest accumulation of gold in spleen around 15 d after injection. A low concentration was detected in brain after 1?d without any residual AuNPs after 30 d. Ultrastructural study of brain tissue also showed few AuNPs in lysosome with no changes in cellular architecture. Renal retention of AuNPs was limited indicating low nephrotoxic potential. AuNPs were detectable in urine till 30 d after single injection indicating slow excretion from the body. No evidence of significant toxicity was observed in hemogram, serum biochemistry, and tissue histology. No mortality, changes in behavior, hair color, weight, and food intake was observed as compared to control mice. Therefore, we conclude that the ultrafine AuNPs are predominantly excreted in urine without any systemic toxicity following i.v. administration and are hence safe for use in drug delivery systems.     

Comparison of chlordecone effects on autoimmunity in (NZBxNZW) F(1) and BALB/c mice

Arecoline, the main areca alkaloid in betel quid (BQ), is reported to have cytotoxic, genotoxic, and mutagenic effects in various cells. It shows strong correlation to the incidence of oral submucous fibrosis, leukoplakia, and oral cancer. To clarify the role of arecoline in BQ-induced carcinogenesis, primary human gingival keratinocyes (GK) and human KB epithelial cells were used for studying the molecular mechanisms of arecoline-mediated cell cycle deregulation for comparison. After 24 h of exposure, arecoline (0.2–0.8 mM) inhibited KB cell growth in a dose- and time-dependent manner with a reduction in cell number by 27–37 and 37–58%, respectively, as determined by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and sulforhodamine B (SRB) assays. Incubation of KB cells with arecoline (0.1–0.4 mM) caused late-S and G2/M phases’ cell cycle arrest. Western blot analysis revealed that arecoline induced cyclin Bl, Wee 1, and phosphorylated cdc2 protein levels whereas it declined p21 protein expression in KB cancer cells. Nevertheless, arecoline induced p21, but decreased cdc2 and cyclin B1 protein levels in GK. We demonstrated that higher concentrations of arecoline (0.2–1.2 mM) induced both cell necrosis and apoptosis as detected by DNA fragmentation and Annexin V–PI staining after long-term (48 h) treatment. Our results suggest that differential regulation of S and/or G2/M cell cycle-related proteins in the GK and KB cells play a crucial role in different stages of BQ-mediated carcinogenesis.     

纳米雄黄抗肿瘤作用及在荷瘤小鼠组织中的分布

目的:研究纳米雄黄抗肿瘤作用和在荷瘤小鼠体内的分布情况,并与原料雄黄进行比较。方法:采用计算抑瘤率的方法研究纳米雄黄对动物移植瘤生长的影响,应用MTT法检测纳米雄黄对体外培养人肿瘤细胞株生长的抑制作用,用石墨炉原子吸收光谱法检测荷瘤小鼠组织样品砷浓度。结果:纳米雄黄对小鼠艾氏腹水癌实体型和小鼠肝癌H22均有抑制作用,且纳米雄黄50 mg·kg-1剂量组的抑瘤作用与原料雄黄100mg·kg-1剂量组的抑瘤作用相当。纳米雄黄对HL-60细胞和U937细胞的抑制作用强于原料雄黄。纳米雄黄组肝、脾、肿瘤中砷浓度显著高于同剂量原料雄黄组。结论:纳米雄黄抗肿瘤作用强于原料雄黄,并具有肝、脾和肿瘤组织靶向性。     

Bacterial endotoxin (lipopolysaccharide) binds to the surface of gold nanoparticles,interferes with biocorona formation and induces human monocyte inflammatory activation

Nanoparticles (NPs) are easily contaminated by bacterial endotoxin (lipopolysaccharide [LPS]). The presence of LPS can be responsible for many immune/inflammatory effects attributed to NPs. In this study, we examined the effects of LPS adsorption on the NP surface on the formation of a biocorona in biological fluids and on the subsequent inflammation-inducing activity of NPs. Different gold (Au) NPs with sizes ranging from 10 to 80?nm and with different surface functionalization (sodium citrate, lipoic acid, and branched polyethyleneimine (BPEI), or polyethylene glycol (PEG)) were exposed to E. coli LPS under different conditions. The binding capacity of LPS to the surface of AuNPs was dose- and time-dependent. LPS attached to sodium citrate and lipoic acid coatings, but did not adhere to BPEI- or PEG-coated NPs. By computational simulation, the binding of LPS to AuNPs seems to follow the Langmuir absorption isotherm. The presence of LPS on AuNP surface interfered and caused a decrease in the formation of the expected biomolecular corona upon incubation in human plasma. LPS-coated AuNPs, but not the LPS-free NPs, induced significant inflammatory responses in vitro. Notably, while free LPS did also induce an anti-inflammatory response, LPS bound to NPs appeared unable to do so. In conclusion, the unintentional adsorption of LPS onto the NP surface can affect the biocorona formation and the inflammatory properties of NPs. Thus, for an accurate interpretation of NP interactions with cells, it is extremely important to be able to distinguish the intrinsic NP biological effects from those caused by biologically active contaminants such as endotoxin.     

Effect of Usuhiratake (Pleurotus pulmonarius) on sneezing and nasal rubbing in BALB/c mice

The anti-rhinitis properties of Pleurotus pulmonarius were investigated in BALB/c mice. A single administration of Pleurotus Pulmonarius caused no significant effect on antigen-induced nasal rubbing and sneezing at a dose of 500 mg/kg, but a significant inhibition was observed after 2 weeks of repeated treatment at this dose, and at a dose of 200 mg/kg, it also caused a significant inhibition after repeated administration for 4 weeks. Pleurotus pulmonarius showed no significant inhibitory effect on the production of IgE. In addition, Pleurotus pulmonarius caused no inhibition of histamine-induced nasal rubbing and sneezing at a dose of 500 mg/kg, but in vitro study, it inhibited histamine release from rat mast cells induced by compound 48/80 at the soluble supernatant solution of 30 and 100 microg/ml of Pleurotus pulmonarius suspended in PBS. These results demonstrated that Pleurotus pulmonarius may be effective in the relief of symptoms of allergic rhinitis through inhibition of histamine release.     

In vitro schistosomicidal activity of the lignan (−)-6,6′-dinitrohinokinin (DNHK) loaded into poly(lactic-co-glycolic acid) nanoparticles against Schistosoma mansoni

Context: (?)-6,6′-Dinitrohinokinin (DNHK) display remarkable antiparasitic activity and was, therefore, incorporated into a nanoparticle formulation.

Objective: Incorporation of DNHK in poly lactic-co-glycolic acid (PLGA) nanoparticles aiming to improve its biological activities.

Materials and methods: Synthesis, characterization and incorporation of DNHK into glycolic acid (PLGA) nanoparticles by nanoprecipitation method. The nanoparticles were characterized by ultraviolet-visible spectroscopy, X-ray diffraction, field emission electron microscopic scanning mansoni (FESEM), and dynamic light scattering (DLS). For the in vitro test with Schistosoma mansoni, the DNHK-loaded PLGA was diluted into the medium, and added at concentrations 10–200?µM to the culture medium containing one adult worm pair. The parasites were kept for 120?h and monitored every 24?h to evaluate their general condition, including: pairing, alterations in motor activity and mortality.

Results: The loaded PLGA nanoparticles gave an encapsulation efficiency of 42.2% and showed spherical characteristics in monodisperse polymeric matrix. The adult worm pairs were separated after 120?h of incubation for concentrations higher than 50?µM of DNHK-loaded PLGA. The groups incubated with 150 and 200?µM of DNHK-loaded PLGA for 24 and 120?h killed 100% of adult worms, afforded LC₅₀ values of 137.0?±?2.12?µM and 79.01?±?1.90?µM, respectively, which was similar to the effect displayed by 10?µM of praziquantel.

Discussion and conclusions: The incorporation of DNHK-loaded showed schistosomicidal activity and allowed its sustained release. The loaded PLGA system can be administered intravenously, as well as it may be internalized by endocytosis by the target organisms.