Extracellular vesicles containing the transferrin receptor as nanocarriers of apotransferrin.

Previous work by our group has shown the pro-differentiating effects of apotransferrin (aTf) on oligodendroglial cells in vivo and in vitro. Further studies showed the remyelinating effect of aTf in animal demyelination models such as hypoxia/ischemia, where the intranasal administration of human aTf provided brain neuroprotection and reduced white matter damage, neuronal loss, and astrogliosis in different brain regions. These data led us to search for a less invasive and controlled technique to deliver aTf to the CNS. To such end, we isolated extracellular vesicles (EVs) from human and mouse plasma and different neuron and glia conditioned media and characterized them based on their quality, quantity, identity, and structural integrity by western blot, dynamic light scattering, and scanning electron microscopy. All sources yielded highly pure vesicles whose size and structures were in keeping with previous literary evidence. Given that, remarkably, EVs from all sources analyzed contained Tf receptor 1 (TfR1) in their composition, we employed two passive cargo-loading strategies which rendered successful EV loading with aTf, specifically through binding to TfR1. These results unveil EVs as potential nanovehicles of aTf to be delivered into the CNS parenchyma, and pave the way for further studies into their possible clinical application in the treatment of demyelinating diseases.

A multiparametric model for the industrialization of co-precipitation synthesis of nano-commodities.

Magnetite superparamagnetic nanoparticles (MNP) are becoming one of the firsts nanocommodity products. MNP find a number of applications and they are been produced at relatively large scale. The co-precipitation method presents many technical and economical advantages among alternative processes. However, the relationships between physical and chemical reaction conditions during the co-precipitation process and the resulting properties of obtained MNP are not yet fully understood. The novelty of this contribution is the establishment of the cross-dependency effects of the main physical and chemical parameters of the co-precipitation reaction on the properties of resulting MNP. The conditions were varied by following an experimental design. The crystallite size, particle size and magnetization of the MNP and the Z-potential and size of their aggregates were selected as main response properties. A set of equations in the form of 4D surface responses in the space of co-precipitation process variables was obtained and analyzed in terms of the resulting properties. The set of equations is useful to predict, optimize and tailor very precisely the properties of resulting MNP as a function of reaction conditions.

Combined Microdialysis-Tumor Homogenate Method for the Study of the Steady State Compartmental Distribution of a Hydrophobic Anticancer Drug in Patient-Derived Xenografts.

PURPOSE: To develop a reproducible microdialysis-tumor homogenate method for the study of the intratumor distribution of a highly hydrophobic anticancer drug (SN-38; 7-ethyl-10-hydroxycamptothecin) in neuroblastoma patient-derived xenografts. METHODS: We studied the nonspecific binding of SN-38 to the microdialysis tubing in the presence of 2-hydroxypropyl-beta-cyclodextrin (HPBCD) in the perfusate. We calibrated the microdialysis probes by the zero flow rate (ZFR) method and calculated the enhancement factor (f = extrapolated SN-38 concentration at the ZFR / SN-38 concentration in the dialysed solution) of HPBCD. We characterized the extravasation of HPBCD to tumors engrafted in mice. In vivo microdialysis and terminal homogenate data at the steady state (subcutaneous pump infusions) were used to calculate the volume of distribution of unbound SN-38 (Vu,tumor) in neuroblastoma. RESULTS: HPBCD (10% w/v) in the perfusate prevented the nonspecific binding of SN-38 to the microdialysis probe and enhanced SN-38 recovery (f = 1.86). The extravasation of HPBCD in the tumor during microdialysis was lower than 1%. Vu,tumor values were above 3 mL/g tumor for both neuroblastoma models and suggested efficient cellular penetration of SN-38. CONCLUSIONS: The method contributes to overcome the limitations of the microdialysis technique in hydrophobic drugs and provides a powerful tool to characterize compartmental anticancer drug distribution in xenografts.

Complexation of a 1-Indanone Thiosemicarbazone with Hydroxypropyl-ß-Cyclodextrin Enhances Its Activity Against a Hepatitis C Virus Surrogate Model.

The current standard of care of the infection by hepatitis C virus (HCV) is effective in a limited number of patients and the high cost hinders therapy affordability and compliance. In this context, the research of new direct-acting antiviral agents (DAAs) for a more effective and long-lasting therapy is an urgent need and an area of active investigation. In an effort to develop novel DAAs, a series of 1-indanone thiosemicarbazones (TSCs) was synthesized and fully characterized. However, the high self-aggregation tendency and extremely poor aqueous solubility of these antiviral candidates often preclude their reliable biological evaluation in vitro. To maintain constant TSC concentrations over the biological assays, different TSC/cyclodextrin complexes were produced. In the present work, we report for the first time the cytotoxicity and antiviral activity of 5,6-dimethoxy TSC inclusion complexes with hydroxypropyl-ß-cyclodextrin on bovine viral diarrhea virus (BVDV) as HCV surrogate model. Results showed a potent suppression of the virus replication, with greater activity for the inclusion complexes than the free compound.

Encapsulation of the antimicrobial and immunomodulator agent nitazoxanide within polymeric micelles.

Nitazoxanide (NTZ) is a highly hydrophobic nitrothiazolyl-salicylamide that displays antimicrobial activity against a variety of parasites, anaerobic bacteria and viruses. More recently, its effectiveness in the pharmacotherapy of chronic hepatitis, the leading cause of liver cirrhosis and hepatocellular carcinoma (HCC), has been reported. On the other hand, the extremely low aqueous solubility of the drug challenges its administration by different routes. The present work explored for the first time the encapsulation of NTZ within pristine, lactosylated and mixed poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) polymeric micelles (PMs) of different architectures, molecular weights and hydrophilic-lipophilic balance (HLB) as a strategy to improve its aqueous solubility and to potentially target it to the liver parenchyma. The solubility was increased up to 609 times. The drug encapsulation modified the self-aggregation pattern of the different amphiphiles, resulting in a sharp growth of the micellar size. The encapsulation capacity of the lactosylated derivatives was smaller than that of the pristine counterparts, though the development of mixed PMs that combine a highly hydrophilic lactosylated amphiphile (e.g., poloxamer F127 or poloxamine T1107) that forms the micellar template and a more hydrophobic unmodified poloxamine (T904) that increases the hydrophobicity of the core resulted in the synergistic encapsulation of the drug and a substantial increase of the physical stability over time. Overall findings confirmed the extremely great versatility of the poloxamer/poloxamine mixed self-assembly systems as Trojan nanocarriers for the encapsulation of NTZ towards its targeting to the liver.

Novel 1-indanone Thiosemicarbazone Antiviral Candidates: Aqueous Solubilization and Physical Stabilization by Means of Cyclodextrins.

PURPOSE: To investigate cyclodextrin-mediated solubilization and physical stabilization of novel 1-indanone thiosemicarbazone (TSC) candidate drugs that display extremely high self-aggregation and precipitation tendency in water. METHODS: TSC/CD complexes were produced by co-solvent method, and TSC/CD phase-solubility diagrams were obtained by plotting TSC concentration as a function of increasing CD concentration. Size, size distribution, and zeta-potential of the different TSC/CD complexes and aggregates were fully characterized by dynamic light scattering. The morphology of the structures was visualized by atomic force microscopy. RESULTS: Results indicated the formation of Type A inclusion complexes; the solubility of different TSCs was enhanced up to 215 times. The study of physical stability revealed that, as opposed to free TSCs that self-aggregate, crystallize, and precipitate in water very rapidly, complexed TSCs remain in solution for at least 1 week. On the other hand, a gradual size growth was observed. This phenomenon stemmed from the self-aggregation of the TSC/CD complex. CONCLUSIONS: 1-indanone TSC/CD inclusion complexes improved aqueous solubility and physical stability of these new drug candidates and constitute a promising technological approach towards evaluation of their activity against the viruses hepatitis B and C.

T908 Polymeric Micelles Improved the Uptake of Sgc8-c Aptamer Probe in Tumor-Bearing Mice: A Co-Association Study between the Probe and Preformed Nanostructures.

Aptamers are oligonucleotides that have the characteristic of recognizing a target with high affinity and specificity. Based on our previous studies, the aptamer probe Sgc8-c-Alexa647 is a promising tool for molecular imaging of PTK7, which is an interesting biomarker in cancer. In order to improve the delivery of this probe as well as create a novel drug delivery nanosystem targeted to the PTK7 receptor, we evaluate the co-association between the probe and preformed nanostructures. In this work, preformed pegylated liposomes (PPL) and linear and branched pristine polymeric micelles (PMs), based on PEO-PPO-PEO triblock copolymers were used: poloxamer F127® and poloxamines T1307® and T908®. For it, Sgc8-c-Alexa647 and its co-association with the different nanostructures was exhaustively analyzed. DLS analysis showed nanometric sizes, and TEM and AFM showed notable differences between free- and co-associated probe. Likewise, all nanosystems were evaluated on A20 lymphoma cell line overexpressing PTK7, and the confocal microscopy images showed distinctness in cellular uptake. Finally, the biodistribution in BALB/c mice bearing lymphoma-tumor and pharmacokinetic study revealed an encouraging profile for T908-probe. All data obtained from this work suggested that PMs and, more specifically T908 ones, are good candidates to improve the pharmacokinetics and the tumor uptake of aptamer-based probes.

Development and Evaluation of 2-Amino-7-Fluorophenazine 5,10-Dioxide Polymeric Micelles as Antitumoral Agents for 4T1 Breast Cancer.

2-Amino-7-fluorophenazine 5,10-dioxide (FNZ) is a bioreducible prodrug, poorly soluble in water, with potential anticancer activity on hypoxic-tumors. This poor solubility limits its potential applications in clinic. Amphiphilic pristine polymeric micelles (PMs) based on triblock copolymers Pluronic® and Tetronic®, glycosylated derivatives and their mixtures with preformed-liposomes (LPS), were analyzed as strategies to improve the bioavailability of FNZ. FNZ encapsulations were performed and the obtaining nanostructures were characterized using UV-visible spectroscopy (UV-VIS), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The most promising nanoformulations were analyzed for their potential toxicity and pharmacologically, at 20 mg/kg FNZ-doses, in a stage-IV murine metastatic-breast tumor model. The results revealed that the solubility of the encapsulated-FNZ increased up to 14 times and the analysis (UV-VIS, DLS and TEM) confirmed the interaction between vehicles and FNZ. In all the cases appropriate encapsulation efficiencies (greater than 75%), monodisperse nanometric particle sizes (PDI = 0.180-0.335), adequate Z-potentials (-1.59 to -26.4 mV), stabilities and spherical morphologies were obtained. The in vitro profile of FNZ controlled releases corresponded mainly to a kinetic Higuchi model. The in vitro/in vivo biological studies revealed non-toxicity and relevant tumor-weight diminution (up to 61%).

Targeted anti-inflammatory peptide delivery in injured endothelial cells using dermatan sulfate/chitosan nanomaterials.

This work describes a novel delivery system for targeting egg-derived anti-inflammatory tripeptide Ile-Arg-Trp (IRW) to endothelial cells. The nanomedicine is synthesized by a simple and reproducible ionotropic gelification method that results in the efficient loading of the positively charged IRW within the dermatan sulfate/ chitosan matrix, as demonstrated by ss-NMR spectroscopy. The incorporation of IRW results in a stable nanoparticle dispersion with a single size population of 442 ±â€¯43 nm. Fluorescence microscopy studies demonstrate the capacity of the nanomaterial to distinguish between a quiescent and an injured endothelium through the interaction of dermatan sulfate with the CD44 receptor. Remarkably, no additional surface functionalization is required as dermatan sulfate mediates their internalization and the intracellular release of this natural anti-inflammatory tripeptide to modulate endothelial inflammatory response. This simple, scalable, and versatile nanotechnology platform opens new opportunities to apply in the therapy of vascular disease.

99mTc-AgNPs-ICG: nanoparticle for hybrid image / 99mTc-AgNPs-ICG: nanopartícula para imagem híbrida / 99mTc-AgNPs-ICG: nanopartícula para imagem híbrida

Introduction: Currently nanotechnology has radically changed the diagnosis of many human pathologies. The aim of this work is to obtain silver nanoparticles for hybrid imaging (99mTc-AgNPs-ICG) having potential clinical imaging applications. Materials and methods: We mixed 2 ml of ascorbic acid (1.7x10-4 M), 5 mCi of 99mTcO4- , 2 ml of citric acid (8.0x10-4 M) and 0.5 ml of silver nitrate (2.5x10-3 M). Solution pH was 5, and it was shaken for 20 minutes at 37º C. Afterwards, 2 µL of Indocyanine Green (1.3x10-3 M) was added (99mTc-AgNPs-ICG). Physiochemical properties of the solution were characterized by UV (λ1 = 420 nm, λ2 = 254 nm) and gamma detector. Fluorescence image, particle size and IR spectrum were evaluated. Results: Silver nanoparticles were obtained in aqueous solution a pH of 5. Their pH, color and spectrum were stable for seven days. Furthermore, the principal peak characterized by HPLC, UV and Gamma detector had similar retention times. Its UV spectrum showed an absorption band of 420 nm, which corresponds to the plasmon absorption band of these nanoparticles. The particle size was 46 nm ± 1.5 nm. The IR spectrum showed absorption bands in 3193, 2624, 1596 y 1212 cm-1. Conclusions: We describe for the first time in literature the synthesis of hybrid (radioactive and fluorescent) silver nanoparticles. Their physiochemical properties were characterized, being stable and their labelling was reproducible having potential biomedical applications.

Introducción: actualmente la nanotecnología ha cambiado radicalmente el diagnóstico de muchas patologías humanas. El objetivo de este trabajo es obtener nanopartículas de plata para imagen híbrida (99mTc-AgNPs-ICG) que tengan potenciales aplicaciones clínicas en imagen. Materiales y métodos: se mezclaron 2 ml de ácido ascórbico (1,7x10-4 M), 5 mCi de 99mTcO4- , 2 ml de ácido cítrico (8,0x10-4 M) y 0,5 ml de nitrato de plata (2,5x10-3 M). El pH de la solución fue 5, y se agitó durante 20 minutos a 37º C. A continuación, se añadieron 2 µl de verde de indocianina (1,3x10-3 M) (99mTc-AgNPs-ICG). Las propiedades fisicoquímicas de la solución se caracterizaron mediante UV (λ1 = 420 nm, λ2 = 254 nm) y detector gamma. Se evaluaron la imagen de fluorescencia, el tamaño de las partículas y el espectro IR. Resultados: se obtuvieron nanopartículas de plata en solución acuosa a un pH de 5. Su pH, color y espectro fueron estables durante siete días. Además, el pico principal caracterizado por HPLC, UV y detector Gamma tenía tiempos de retención similares. Su espectro UV mostró una banda de absorción de 420 nm, que corresponde a la banda de absorción plasmónica de estas nanopartículas. El tamaño de las partículas era de 46 nm ± 1,5 nm. El espectro IR mostró bandas de absorción en 3193, 2624, 1596 y 1212 cm-1. Conclusiones: describimos por primera vez en la literatura la síntesis de nanopartículas de plata híbridas (radioctivas y fluorescentes). Se caracterizaron sus propiedades fisicoquímicas, siendo estables y su etiquetado fue reproducible teniendo potenciales aplicaciones biomédicas.

Introdução: atualmente, a nanotecnologia mudou radicalmente o diagnóstico de muitas patologias humanas. O objetivo deste trabalho é obter nanopartículas de prata para imagens híbridas (99mTc-AgNPs-ICG) com possíveis aplicações de imagens clínicas. Materiais e métodos: misturamos 2 ml de ácido ascórbico (1,7x10-4 M), 5 mCi de 99mTcO4- , 2 ml de ácido cítrico (8,0x10-4 M) e 0,5 ml de nitrato de prata (2,5x10-3 M). O pH da solução era 5 e ela foi agitada por 20 minutos a 37º C. Em seguida, foram adicionados 2 µL de indocianina verde (1,3x10-3 M) (99mTc-AgNPs-ICG). As propriedades físico-químicas da solução foram caracterizadas por UV (λ1 = 420 nm, λ2 = 254 nm) e detector gama. A imagem de fluorescência, o tamanho das partículas e o espectro de infravermelho foram avaliados. Resultados: as nanopartículas de prata foram obtidas em solução aquosa com pH de 5. Seu pH, cor e espectro permaneceram estáveis por sete dias. Além disso, o pico principal caracterizado por HPLC, UV e detector gama teve tempos de retenção semelhantes. Seu espectro de UV mostrou uma banda de absorção de 420 nm, que corresponde à banda de absorção plasmônica dessas nanopartículas. O tamanho da partícula foi de 46 nm ± 1,5 nm. O espectro de IV mostrou bandas de absorção em 3193, 2624, 1596 e 1212 cm-1. Conclusões: descrevemos pela primeira vez na literatura a síntese de nanopartículas de prata híbridas (radioativas e fluorescentes). Suas propriedades físico-químicas foram caracterizadas, sendo estáveis e sua rotulagem foi reprodutível, com possíveis aplicações biomédicas.

99mTc-AgNPs-ICG: nanopartícula para imagen híbrida / 99mTc-AgNPs-ICG: nanoparticle for hybrid image / 99mTc-AgNPs-ICG: nanopartícula para imagem híbrida

Introducción: actualmente la nanotecnología ha cambiado radicalmente el diagnóstico de muchas patologías humanas. El objetivo de este trabajo es obtener nanopartículas de plata para imagen híbrida (99mTc-AgNPs-ICG) que tengan potenciales aplicaciones clínicas en imagen. Materiales y métodos: se mezclaron 2 ml de ácido ascórbico (1.7 x10-4 M), 5 mCi de 99mTcO4-, 2 ml de ácido cítrico (8.0 x 10-4 M) y 0.5 ml de nitrato de plata (2.5 x 10-3 M). El pH de la solución fue 5, y se agitó durante 20 minutos a 37º C. A continuación, se añadieron 2 µl de verde de indocianina (1.3 x 10-3 M) (99mTc-AgNPs-ICG). Las propiedades fisicoquímicas de la solución se caracterizaron mediante UV (λ1 = 420 nm, λ2 = 254 nm) y detector gamma. Se evaluaron la imagen de fluorescencia, el tamaño de las partículas y el espectro IR. Resultados: se obtuvieron nanopartículas de plata en solución acuosa a un pH de 5. Su pH, color y espectro fueron estables durante siete días. Además, el pico principal caracterizado por HPLC, UV y detector Gamma tenía tiempos de retención similares. Su espectro UV mostró una banda de absorción de 420 nm, que corresponde a la banda de absorción plasmónica de estas nanopartículas. El tamaño de las partículas era de 46 nm ± 1,5 nm. El espectro IR mostró bandas de absorción en 3193, 2624, 1596 y 1212 cm-1. Conclusiones: describimos por primera vez en la literatura la síntesis de nanopartículas de plata híbridas (radioactivas y fluorescentes). Se caracterizaron sus propiedades fisicoquímicas, siendo estables y su etiquetado fue reproducible teniendo potenciales aplicaciones biomédicas.

Introduction: Currently nanotechnology has radically changed the diagnosis of many human pathologies. The aim of this work is to obtain silver nanoparticles for hybrid imaging (99mTc-AgNPs-ICG) having potential clinical imaging applications. Materials and methods: We mixed 2 ml of ascorbic acid (1.7x10-4 M), 5 mCi of 99mTcO4-, 2 ml of citric acid (8.0 x 10-4 M) and 0.5 ml of silver nitrate (2.5 x 10-3 M). Solution pH was 5, and it was shaken for 20 minutes at 37º C. Afterwards, 2 µL of Indocyanine Green (1.3 x 10-3 M) was added (99mTc-AgNPs-ICG). Physiochemical properties of the solution were characterized by UV (λ1 = 420 nm, λ2 = 254 nm) and gamma detector. Fluorescence image, particle size and IR spectrum were evaluated. Results: Silver nanoparticles were obtained in aqueous solution a pH of 5. Their pH, color and spectrum were stable for seven days. Furthermore, the principal peak characterized by HPLC, UV and Gamma detector had similar retention times. Its UV spectrum showed an absorption band of 420 nm, which corresponds to the plasmon absorption band of these nanoparticles. The particle size was 46 nm ± 1.5 nm. The IR spectrum showed absorption bands in 3193, 2624, 1596 y 1212 cm-1. Conclusions: We describe for the first time in literature the synthesis of hybrid (radioactive and fluorescent) silver nanoparticles. Their physiochemical properties were characterized, being stable and their labelling was reproducible having potential biomedical applications.

Introdução: Atualmente, a nanotecnologia mudou radicalmente o diagnóstico de muitas patologias humanas. O objetivo deste trabalho é obter nanopartículas de prata para imagens híbridas (99mTc-AgNPs-ICG) com possíveis aplicações de imagens clínicas. Materiais e métodos: Misturamos 2 ml de ácido ascórbico (1.7 x 10-4 M), 5 mCi de 99mTcO4-, 2 ml de ácido cítrico (8.0 x 10-4 M) e 0.5 ml de nitrato de prata (2.5 x 10-3 M). O pH da solução era 5 e ela foi agitada por 20 minutos a 37º C. Em seguida, foram adicionados 2 µL de indocianina verde (1,3x10-3 M) (99mTc-AgNPs-ICG). As propriedades físico-químicas da solução foram caracterizadas por UV (λ1 = 420 nm, λ2 = 254 nm) e detector gama. A imagem de fluorescência, o tamanho das partículas e o espectro de infravermelho foram avaliados. Resultados: As nanopartículas de prata foram obtidas em solução aquosa com pH de 5. Seu pH, cor e espectro permaneceram estáveis por sete dias. Além disso, o pico principal caracterizado por HPLC, UV e detector gama teve tempos de retenção semelhantes. Seu espectro de UV mostrou uma banda de absorção de 420 nm, que corresponde à banda de absorção plasmônica dessas nanopartículas. O tamanho da partícula foi de 46 nm ± 1,5 nm. O espectro de IV mostrou bandas de absorção em 3193, 2624, 1596 e 1212 cm-1. Conclusões: Descrevemos pela primeira vez na literatura a síntese de nanopartículas de prata híbridas (radioativas e fluorescentes). Suas propriedades físico-químicas foram caracterizadas, sendo estáveis e sua rotulagem foi reprodutível, com possíveis aplicações biomédicas.

Sulfanilic acid-modified chitosan mini-spheres and their application for lysozyme purification from egg white.

A cation exchange matrix with zwitterionic and multimodal properties was synthesized by a simple reaction sequence coupling sulfanilic acid to a chitosan based support. The novel chromatographic matrix was physico-chemically characterized by ss-NMR and ζ potential, and its chromatographic performance was evaluated for lysozyme purification from diluted egg white. The maximum adsorption capacity, calculated according to Langmuir adsorption isotherm, was 50.07 ± 1.47 mg g-1 while the dissociation constant was 0.074 ± 0.012 mg mL-1 . The process for lysozyme purification from egg white was optimized, with 81.9% yield and a purity degree of 86.5%, according to RP-HPLC analysis. This work shows novel possible applications of chitosan based materials. The simple synthesis reactions combined with the simple mode of use of the chitosan matrix represents a novel method to purify proteins from raw starting materials. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:387-396, 2018.

Development of fluorescent- and radio-traceable T1307-polymeric micelles as biomedical agents for cancer diagnosis: biodistribution on 4T1 tumor-bearing mice

Abstract In recent years, nanocarriers have been studied as promising pharmaceutical tools for controlled drug-delivery, treatment-efficacy follow-up and disease imaging. Among them, X-shaped amphiphilic polymeric micelles (Tetronic®, poloxamines) display great potential due to their biocompatibility and non-toxic effects, among others. In the present work, polymeric micelles based on the T1307 copolymer were initially decorated with a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-fluorophore in order to determinate its in vivo biodistribution on 4T1 tumor-bearing mice. However, unfavorable results with this probe led to two different strategies. On the one hand, the BODIPY-micelle-loaded, L-T1307-BODIPY, and on the other hand, the 99mTc-micelle-radiolabeled, L-T1307- 99m Tc, were analyzed separately in vivo. The results indicated that T1307 accumulates mainly in the stomach, the kidneys, the lungs and the tumor, reaching the maximum organ-accumulation 2 hours after intravenous injection. Additionally, and according to the results obtained for L-T1307- 99m Tc, the capture of the polymeric micelles in organs could be observed up to 24 hours after injection. The results obtained in this work were promising towards the development of new radiotracer agents for breast cancer based on X-shaped polymeric micelles.

Targeted drug distribution in tumor extracellular fluid of GD2-expressing neuroblastoma patient-derived xenografts using SN-38-loaded nanoparticles conjugated to the monoclonal antibody 3F8.

Neuroblastoma is a pediatric solid tumor with high expression of the tumor associated antigen disialoganglioside GD2. Despite initial response to induction therapy, nearly 50% of high-risk neuroblastomas recur because of chemoresistance. Here we encapsulated the topoisomerase-I inhibitor SN-38 in polymeric nanoparticles (NPs) surface-decorated with the anti-GD2 mouse mAb 3F8 at a mean density of seven antibody molecules per NP. The accumulation of drug-loaded NPs targeted with 3F8 versus with control antibody was monitored by microdialysis in patient-derived GD2-expressing neuroblastoma xenografts. We showed that the extent of tumor penetration by SN-38 was significantly higher in mice receiving the targeted nano-drug delivery system when compared to non-targeted system or free drug. This selective penetration of the tumor extracellular fluid translated into a strong anti-tumor effect prolonging survival of mice bearing GD2-high neuroblastomas in vivo.

Chitosan-g-oligo(epsilon-caprolactone) polymeric micelles: microwave-assisted synthesis and physicochemical and cytocompatibility characterization.

With the aim to produce mucoadhesive polymeric micelles for drug administration by mucosal routes, chitosan-g-oligo(epsilon-caprolactone) copolymers were synthesized by the microwave-assisted ring-opening polymerization of epsilon-caprolactone using chitosan as the macroinitiator and methanesulfonic acid as the solvent, catalyst and protecting group of the amine moieties. The reaction was conducted under very mild conditions and was completed within 10 min with a monomer conversion above 90%. The grafting of oligo(epsilon-caprolactone) blocks to the free hydroxyl groups of chitosan was confirmed by ATR/FT-IR, 1H- and 13C-NMR, WAXD and thermal analysis (TGA/DSC). The molecular weight of the synthetic hybrid copolymers was determined by GPC and MALDI-ToF mass spectrometry. Polymeric micelles obtained by the solvent diffusion/evaporation method showed a spherical shape (TEM and AFM) with sizes between 111 and 154 nm and highly positive zeta potential (>+50 mV) (DLS). In addition, they displayed good cell compatibility in the human lung adenocarcinoma epithelial line, A549, and were readily up-taken by the cervical cancer cell line, HeLa. Results from the encapsulation of the antituberculosis drug, rifampicin, showed that the micelles had better performance than other nanocarriers previously investigated (e.g., cyclodextrins). Moreover, the micelles conserved the mucoadhesiveness displayed by pristine chitosan and are expected to transiently open tight cell junctions and lead to more prolonged residence times in mucosal tissues and greater drug bioavailability.

Novel poly(ethylene oxide)-b-poly(propylene oxide) copolymer-glucose conjugate by the microwave-assisted ring opening of a sugar lactone.

In this work, we investigated for the first time the conjugation of gluconolactone to a poly(ethylene oxide)-poly(propylene oxide) block copolymer by a microwave-assisted ring opening reaction. The glucosylated copolymer was obtained with high yield (90%). A conjugation extent of approximately 100% was achieved within 15 min. The modification reduced the critical micellar concentration and increased the size of the micelles. The agglutination of the modified polymeric micelles by a soluble lectin that binds glucose confirmed the recognizability of the modified nanocarrier. Finally, the solubilization of darunavir, an anti-HIV protease inhibitor, showed a sharp increase of the aqueous solubility from 91 microgram/mL to 14.2 and 18.9 mg/mL for 10% w/v pristine and glucosylated polymeric micelles, respectively.

ß-Cyclodextrin hydrogels for the ocular release of antibacterial thiosemicarbazones.

Two types of hydrophilic networks with conjugated beta-cyclodextrin (ß-CD) were developed with the aim of engineering useful platforms for the localized release of an antimicrobial 5,6-dimethoxy-1-indanone N4-allyl thiosemicarbazone (TSC) in the eye and its potential application in ophthalmic diseases. Poly(2-hydroxyethyl methacrylate) soft contact lenses (SCLs) displaying ß-CD, namely pHEMA-co-ß-CD, and super-hydrophilic hydrogels (SHHs) of directly cross-linked hydroxypropyl-ß-CD were synthesized and characterized regarding their structure (ATR/FT-IR), drug loading capacity, swelling and in vitro release in artificial lacrimal fluid. Incorporation of TSC to the networks was carried out both during polymerization (DP method) and after synthesis (PP method). The first method led to similar drug loads in all the hydrogels, with minor drug loss during the washing steps to remove unreacted monomers, while the second method evidenced the influence of structural parameters on the loading efficiency (proportion of CD units, mesh size, swelling degree). Both systems provided a controlled TSC release for at least two weeks, TSC concentrations (up to 4000µg/g dry hydrogel) being within an optimal therapeutic window for the antimicrobial ocular treatment. Microbiological tests against P. aeruginosa and S. aureus confirmed the ability of TSC-loaded pHEMA-co-ß-CD network to inhibit bacterial growth.

Antiviral activity against the hepatitis C virus (HCV) of 1-indanone thiosemicarbazones and their inclusion complexes with hydroxypropyl-ß-cyclodextrin.

The hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis in humans. Approximately 5% of the infected people die from cirrhosis or hepatocellular carcinoma. The current standard therapy comprises a combination of pegylated-interferon alpha and ribavirin. Due to the relatively low effectiveness, the prohibitive costs and the extensive side effects of the treatment, an intense research for new direct-acting anti-HCV agents is taking place. Furthermore, NS3 protease inhibitors recently introduced into the market are not effective against all HCV subgenotypes. Thiosemicarbazones (TSCs) have shown antiviral activity against a wide range of DNA and RNA viruses. However, their extremely low aqueous solubility and high self-aggregation tendency often preclude their reliable biological evaluation in vitro. In this work, we investigated and compared for the first time the anti-HCV activity of two 1-indanone TSCs, namely 5,6-dimethoxy-1-indanone TSC and 5,6-dimethoxy-1-indanone N4-allyl TSC, and their inclusion complexes with hydroxypropyl-ß-cyclodextrin (HPß-CD) in Huh-7.5 cells containing the full-length and the subgenomic subgenotype 1b HCV replicon system. Studies of physical stability in culture medium showed that free TSCs precipitated rapidly and formed submicron aggregates. Conversely, TSC complexation with HPß-CD led to more stable systems with minimal size growth and drug concentration loss. More importantly, both TSCs and their inclusion complexes displayed a potent suppression of the HCV replication in both cell lines with no cytotoxic effects. The mechanism likely involves the inhibition of non-structural proteins of the virus. In addition, findings suggested that the cyclodextrin released the drug to the culture medium over time. This platform could be exploited for the study of the drug toxicity and pharmacokinetics animal models.

Micro-encapsulated secretory leukocyte protease inhibitor decreases cell-mediated immune response in autoimmune orchitis.

AIMS: We previously reported that recombinant human Secretory Leukocyte Protease Inhibitor (SLPI) inhibits mitogen-induced proliferation of human peripheral blood mononuclear cells. To determine the relevance of this effect in vivo, we investigated the immuno-regulatory role of SLPI in an experimental autoimmune orchitis (EAO) model. MAIN METHODS: In order to increase SLPI half life, poly-ε-caprolactone microspheres containing SLPI were prepared and used for in vitro and in vivo experiments. Multifocal orchitis was induced in Sprague-Dawley adult rats by active immunization with testis homogenate and adjuvants. Microspheres containing SLPI (SLPI group) or vehicle (control group) were administered s.c. to rats during or after the immunization period. KEY FINDINGS: In vitro SLPI-release microspheres inhibited rat lymphocyte proliferation and retained trypsin inhibitory activity. A significant decrease in EAO incidence was observed in the SLPI group (37.5%) versus the control group (93%). Also, SLPI treatment significantly reduced severity of the disease (mean EAO score: control, 6.33±0.81; SLPI, 2.72±1.05). In vivo delayed-type hypersensitivity and ex vivo proliferative response to testicular antigens were reduced by SLPI treatment compared to control group (p<0.05). SIGNIFICANCE: Our results highlight the in vivo immunosuppressive effect of released SLPI from microspheres which suggests its feasible therapeutic use.

Molecular implications in the nanoencapsulation of the anti-tuberculosis drug rifampicin within flower-like polymeric micelles.

Tuberculosis (TB) is the second most deadly infectious disease behind the Human Immunodeficiency Virus (HIV). An effective pharmacotherapy has been available for more than 5 decades. However, the length of the treatment and the pill burden result in low patient compliance and adherence to the regimens. Nanotechnologies can overcome these basic technological drawbacks. The present work explored the molecular implications governing the encapsulation and water solubilization of RIF within flower-like micelles of poly(epsilon-caprolactone)-b-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) block copolymers. Ten derivatives of different molecular weight and hydrophobic/hydrophilic caprolactone/ethylene oxide ratio (CL/EO) were synthesized by a fast and high-yield Microwave-Assisted Polymer Synthesis (MAPS) technique; CL/EO values are determined by taking the ratios of the number of repeating units in the PCL and the PEG segments. The aggregation behavior of the copolymers was thoroughly investigated by means of surface tension (critical micellar concentration), dynamic light scattering (size, size distribution and zeta potential) and transmission electron microscopy (morphology). In general, the greater the central PEG segment, the larger the micelles formed. The physical stability was intimately associated with the molecular weight and the composition. Then, the encapsulation of RIF in the different copolymer families was evaluated, and the physical stability of the drug-loaded aggregates characterized. The micellar size appears as the most crucial property, this phenomenon being primarily controlled by the molecular weight of the PEG central block. Having expressed this, sufficiently high CL/EO ratios (and long PCL segments) are also demanded to attain stable micellar systems with cores that are large enough to host the bulky RIF molecule.