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Transdermal immunization is highly attractive because of the skin's accessibility and unique immunological characteristics. However, it remains a relatively unexplored route of administration because of the great difficulty of transporting antigens past the outermost layer of skin, the stratum corneum. In this article, the abilities of three poly(N-vinylcaprolactam) (PVCL)-based thermoresponsive assemblies - PVCL hydrogels and nanogels plus novel film forming PVCL/acrylic nanogels - to act as protein delivery systems were investigated. Similar thermal responses were observed in all systems, with transition temperatures close to 32 °C, close to that of the skin surface. The investigated dermal delivery systems showed no evidence of cytotoxicity in human fibroblasts and were able to load and release ovalbumin (OVA), a well-studied antigen, in a temperature-dependent manner in vitro. The penetration of OVA into ex vivo human skin following topical application was evaluated, where enhanced skin delivery was seen for the OVA-loaded PVCL systems relative to administration of the protein alone. The distinct protein release and skin penetration profiles observed for the different PVCL assemblies were here discussed on the basis of their structural differences. Fil: Sonzogni, Ana Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Yealland, Guy. Universidad Libre de Berlin; Alemania Fil: Kar, Mrityunjoy. Universidad Libre de Berlin; Alemania Fil: Wedepohl, Stefanie. Universidad Libre de Berlin; Alemania Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Hedtrich, Sarah. Universidad Libre de Berlin; Alemania Fil: Calderon, Marcelo. Universidad Libre de Berlin; Alemania Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Thermoresponsive nanogels (NGs) with film-forming ability could have great potential in delivery system platforms with controlled and targeted release of drugs or proteins, such as in topical treatment. This platform offers the opportunity of combining both the high loading capacity of an NG dispersion and the delivery capability from a film, which could be previously obtained or directly formed onto the surface where the release is required. Therefore, this article investigates the synthesis of NGs based on poly(N-vinylcaprolactam), a thermoresponsive polymer, and poly(butyl acrylate), which promotes particle coalescence and cohesivity (i.e., film forming). The synthesized NGs have low cytotoxicity and are able to form flexible and smooth films, conserving the thermoresponsivity of the particulated system. The obtained films loaded with a model protein show delivery profiles responsive to temperature changes. Fil: Sonzogni, Ana Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Passeggi, Mario Cesar Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; Argentina Fil: Wedepohl, Stefanie. Freie Universität Berlin; Fil: Calderon, Marcelo. Universidad Nacional de Córdoba; Argentina Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

Objectives: To obtain and assess stable cage-like particles with low surface charge density, which can be prepared using a standardized, economic and scalable method. Methods: To form these nanoparticles, the lipid composition and proportion as well the method were modified in relation to cage-like particles previously described elsewhere. Bovine albumin was used to compare ISPA performance with that of other adjuvants in mice and to assess stability. Adjuvant efficacy was analysed using a mouse model of Trypanosoma cruzi infection, which shows protection against an intracellular infection that needs a strong cellular response. Key findings: The new particles were better in terms of level, kinetics and profile of humoral responses than Freund Adjuvant, aluminium hydroxide and Montanide TM ISA 206; they also tended to improve ISCOMATRIX? performance. Particle size and adjuvant performance were conserved during the 6-month period assessed after preparation. In the model of Trypanosoma cruzi infection, mice immunized with ISPA and trans-sialidase developed high protection. Conclusions: The obtained nanoparticles were stable and outperformed the other assessed adjuvants in joining together the capacity of most adjuvants to enhance the immune response against specific antigen, to reduce the number of doses, to homogenize the response between individuals and to reach a balanced TH1/TH2 response. Fil: Bertona, Daiana. Universidad Nacional del Litoral; Argentina Fil: Pujato, Nazarena. Universidad Nacional del Litoral; Argentina Fil: Bontempi, Iván. Universidad Nacional del Litoral; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina. Universidad Nacional del Litoral; Argentina Fil: Cabrera, Gabriel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral; Argentina Fil: Gugliotta, Luis Marcelino. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Hozbor, Daniela Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Nicastro, Alcides. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Calvinho, Luis Fernando. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Marcipar, Iván Sergio. Universidad Nacional del Litoral; Argentina

The acute phase recombinant protein of Toxoplasma gondii P22Ag was expressed and purified and thehomogenate of the parasite was obtained from an infected mouse. These antigens were used to producelatex-protein complexes (LPC) through physical adsorption and chemical coupling onto different latexes,with the aim of producing immunoagglutination (IA) reagents able to detect recently acquiredtoxoplasmosis. Polystyrene and ?core-shell? latexes where employed, exhibiting varied particle size,functionality (carboxyl or epoxy), and charge density. In sensitization experiments for producing LPC, therecombinant protein showed better coupling efficiency onto the particles surface than the homogenateand this could be explained by the complex mixture of the homogenate, which includes a large numberof proteins of different molecular mass, isoelectric points, and hydrophobicity. The synthesized LPC wereemployed in IA assays. To this effect, the agglutination reaction was followed by measuring the changesin the optical absorbance by turbidimetry. Experiments against control sera were performed to evaluatethe performance of various LPC and it was observed that the IA test based on P22Ag and thecarboxylated latex of 350 nm of particle diameter allowed a good discrimination between acute sera andchronic/negative ones. The proposed test is cheap, rapid, and easy to implement. Fil: Peretti, Leandro Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Gonzalez, Veronica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Costa, Juan Gabriel. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marcipar, Ivan Sergio. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

The grafting of casein to acrylic polymers is needed to fully exploit the possibilities of hybrid nanoparticles containing such materials. The explored alternative up to now, based on the primary radical formation onto the protein chains through the redox initiation between the casein amino groups and a hydroperoxide, produces a limited degree of compatibilization to guarantee the synergic effect between both components. A novel strategy that overcomes these limitations is presented. The strategy is based on the use of a crosslinkable casein, which in addition to the characteristic grafting capacity by redox initiation with hydroperoxides, contains acrylic groups able to radically polymerize. The degree of grafting of both acrylic and casein is significantly increased by functionalizing casein with varied amounts of pendant propagating points per protein. Moreover, it is observed that the improved degree of compatibility obtained when using the crosslinkable casein considerably enhanced the properties of the acrylic/casein films, such as their mechanical behavior and resistance to both water and organic solvent. Fil: Picchio, Matías Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: González, Verónica Doris Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Barandiaran, María J.. Universidad del País Vasco; España Fil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina

We have evaluated blood samples of chronic and congenital Trypanosoma cruzi-infected patients from the city of Reconquista located in the northeast of Argentina where no information was previously obtained about the genotype of infecting parasites. Fourteen samples of congenital and 19 chronical patients were analyzed by hybridization with DNA probes of minicircle hypervariable regions (mHVR). In congenital patients, 50% had single infections with TcIId, 7% single infections with TcIIe, 29% mixed infections with TcIId/e, and 7% had mixed infections with TcIId/b and 7% TcIId/b, respectively. In Chronical patients, 52% had single infections with TcIId, 11% single infections with TcIIe, 26% had mixed infections with TcIId/e, and 11% had non-identified genotypes. With these samples, we evaluated the minicircle lineage-specific polymerase chain reaction assay (MLS-PCR), which involves a nested PCR to HVR minicircle sequences and we found a correlation with hybridization probes of 96.4% for TcIId and 54.8% for TcIIe.

The aim of this work was to determine the best strategy to display antigens (Ags) on immunochemical devices to improve test selectivity and sensitivity. We comparatively evaluated five Trypanosoma cruzi antigenic recombinant peptides, chose the three more sensitive ones, built up chimeras bearing these selected Ags, and systematically compared by enzyme-linked immunosorbent assay the performance of the assortments of those peptides with that of the multiepitope constructions bearing all those peptides lineally fused. The better-performing Ags that were compared included peptides homologous to the previously described T. cruzi flagellar repetitive Ag (here named RP1), shed acute-phase Ag (RP2), B13 (RP5), and the chimeric recombinant proteins CP1 and CP2, bearing repetitions of RP1-RP2 and RP1-RP2-RP5, respectively. The diagnostic performances of these Ags were assessed for discrimination efficiency by the formula +OD/cutoff value (where +OD is the mean optical density value of the positive serum samples tested), in comparison with each other either alone, in mixtures, or as peptide-fused chimeras and with total parasite homogenate (TPH). The discrimination efficiency values obtained for CP1 and CP2 were 25% and 52% higher, respectively, than those of their individual-Ag mixtures. CP2 was the only Ag that showed enhanced discrimination efficiency between Chagas´ disease-positive and -negative samples, compared with TPH. This study highlights the convenience of performing immunochemical assays using hybrid, single-molecule, chimeric Ags instead of peptide mixtures. CP2 preliminary tests rendered 98.6% sensitivity when evaluated with a 141-Chagas´ disease-positive serum sample panel and 99.4% specificity when assessed with a 164-Chagas´ disease-negative serum sample panel containing 15 samples from individuals infected with Leishmania spp. Fil: Camussone, Cecilia María. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Tecnología Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: González, Verónica Doris Guadalupe. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Tecnología Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Belluzo, María Soledad. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pujato, Nazarena. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Tecnología Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ribone, María Élida. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; Argentina Fil: Lagier, Claudia Marina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Analítica; Argentina Fil: Marcipar, Iván Sergio. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Tecnología Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina