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Made available in DSpace on 2022-04-29T08:32:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The incorporation of drugs in nanocomposites can be considered a potential strategy for controlled drug release. In this study, a nanocomposite based on bacterial cellulose and the palygorskite clay (BC/PLG) was produced and loaded with metronidazole (MTZ). The samples were characterized using X-ray diffraction (XRD) Spectroscopy, thermal analysis (TG/DTG) and Scanning Electron Microscopy (SEM). The barrier properties were determined to water vapor permeability (WVP). Adsorption tests with PLG were performed using MTZ and drug release profile of the membranes was investigated. The results indicated that PLG increased the crystallinity of the nanocomposites, and greater thermal stability when PLG concentration was 15.0% (BC/PLG15) was observed. WVP of the samples also varied, according to the clay content. Adsorption equilibrium was achieved from 400 mg/L of the PLG and a plateau in the MTZ release rates from BC/PLG was observed after 30 min. Therefore, the results of this study show the potential of these nanocomposite membranes as a platform for controlled drug release. São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Drugs and Medicines, Rodovia Araraquara-Jaú, km 1, - Campus Ville Research Center on Biotechnology Uniara LIMAV Interdisciplinary Laboratory for Advanced Materials Federal University of Piaui, Campus Universitário Ministro Petrônio Portella Center for Mineral Technology, Cidade Universitária São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Drugs and Medicines, Rodovia Araraquara-Jaú, km 1, - Campus Ville FAPESP: 2013/07793-6 FAPESP: 2018/25512-8 FAPESP: 2019/19817-3 CNPq: 407822/2018-6

The treatment of cutaneous leishmaniasis (CL) in Brazil using pentavalent antimony (Sbv) is associated with a high failure rate and long time to heal. Moreover, standard Sbv treatment cures only 50–60% of the cases. In this pilot clinical trial, we evaluated the topical use of bacterial cellulose (BC) bio-curatives + Sbv in the treatment of CL caused by L. braziliensis, in Bahia, Brazil. A total of 20 patients were randomized in two groups assigned to receive either parenteral Sbv alone or parenteral Sbv plus topically applied BC bio-curatives. CL patients treated with Sbv + topical BC bio-curatives had a significantly higher cure rate at 60 days post initiation of treatment compared to CL patients treated with Sbv alone (P=0.01). At day 90 post initiation of treatment, cure rate was similar in the two groups as was overall healing time. Adverse effects or local reactions to topical BC application were not observed. This pilot trial shows that the potential use of a combined therapy consisting of topical BC bio-curatives and parenteral Sbv in favoring healing of CL lesions caused by L. braziliensis, at an early time point.

Made available in DSpace on 2021-06-25T11:03:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-13 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Instituto Nacional de Fotônica Bacterial nanocellulose (BNC) is a natural biopolymer obtained by gram-negative bacteria by means of a green and inexhaustible biotechnological process using glucose as producing source. BCN hydrogels is formed by cellulose nanofibrils that maintain an open network structure, an ideal matrix to produce new class of organic-inorganic nanocomposites (OIN) for multifunctional applications. The polyoxometalates (POMs) are complex molecules with several metallic ions sharing oxide ions, forming a highly symmetrical metal oxide cluster. Phosphotungstic acid (PWA), H3PW12O40 photoreduction process activated under ultraviolet irradiation, promoting color change. In this work, photochromic organic-inorganic nanocomposites were prepared by soaking phosphotungstic acid (H3PW12O40) in wet BNC membranes mats at room temperature. Semi-transparent and free-standing BNC/PWA nanocomposite with paper-like aspect were obtained. BNC network was able to control, stabilize and disperse PWA particles in a narrow nanometric distribution, and FTIR spectra indicated that the primary Keggin structure was also preserved in the nanocomposites, independently on the PWA content. The nanoparticles present a narrow distribution of around 16 nm, independently on the PWA concentration. BNC/PWA nanocomposites showed reversible photochromic behavior characteristic of the equilibrium between different tungsten oxidation states. PWA reduction (W6+→ W5+) and organic matrix oxidation is proposed to occur through a radical process involving the interaction of one electron from the oxygen atom of the PWA and one hydrogen from BNC matrix. The photochromic effect vanishes almost completely after 5 h. This mechanism is real in the presence of oxygen, however, if the membranes are left in nitrogen or under vacuum the blue color remains longer than 45 days. Photo-electrochemical behavior was studied by spectroelectrochemistry measurements. It is worth noting that all processes were still reversible in the timescale of the experiment and color changes were observed in several cycles. Institute of Chemistry São Paulo State University (UNESP) Laboratório de Biopolímeros e Biomateriais (BioPolMat) Universidade de Araraquara Instituto de Química – Universidade de São Paulo USP Departamento de Física Instituto de Ciências Exatas Universidade Federal de Juiz de Fora (UFJF) Deparment of Chemistry Federal University of São Departamento de Física Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) Institute of Chemistry São Paulo State University (UNESP) FAPESP: 2013/07793-6 FAPESP: 2013/24725-4 FAPESP: 2014/12424-2 FAPESP: 2016/11591-8 FAPESP: 2018/25512-8 FAPESP: 2020/04509-9 Instituto Nacional de Fotônica: 407822/2018-6

Transparent and flexible bionanocomposites with photochromic properties based on cellulose triacetate (CTA) and sol-gel synthesized V2O5 nanoparticles were prepared. Poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (EPE) triblock copolymer was added to achieve nanostructured materials and simultaneously control the dispersion of synthesized V2O5 nanoparticles. Investigated bionanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), atomic force microscopy (AFM), tensile tests, and UV–vis spectroscopy. FTIR results confirmed the presence of hydrogen bonds in the bionanocomposites. The miscibility between components improved with the increase of sol-gel content resulting in a decrease of the Tg and Tm of CTA phase as indicated by DSC results. Addition of EPE triblock copolymer enhanced the photochromic properties of bionanocomposites reducing the time of recovery to the initial state after 5 min of UV light irradiation. The biocompatibility of pure CTA and EPE/CTA blends as well as the photochromic properties provided by synthesized V2O5 nanoparticles make their transparent and flexible bionanocomposites ideal for possible future applications.

Made available in DSpace on 2019-10-06T16:58:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nowadays there is a demand for ecologically efficient sustainable materials. The combination of cellulose and clay can provide materials with improved mechanical, thermal, and optical properties, besides better water and gas barrier, and flame resistance than pristine polymers. In the present work, composites were produced using cellulose nanofibers (CNF) and Laponite. The presence of clay modified the properties of the composite films compared to the pristine cellulose nanofibers film, such as lower CNF aggregation, better thermal stability (45 °C for CNF/Lap 3.5:1 by mass) and higher water vapor permeability (157% for CNF/Lap 1:1). In addition, XRD data suggested isolation of different types of CNF/Laponite composites when the mass ratio is modified, pointing out applications for these materials as for instance scaffold in tissue engineering, in regenerative medicine or as drug delivery systems. Institute of Chemistry São Paulo State University-UNESP, CP 355 Research Center on Biotechnology – Uniara, Street: Carlos Gomes, 1338, Centro Department of Fundamental Chemistry Institute of Chemistry University of São Paulo (USP), Av. Prof. Lineu Prestes 748 Institute of Chemistry São Paulo State University-UNESP, CP 355

As deformidades ósseas, congênitas ou resultantes de traumas, apresentam um desafio para seu reparo por tratar-se de um processo demorado com resultados frequentemente imprevisíveis, com elevada importância econômica. A engenharia de tecidos consiste na regeneração de órgãos e tecidos vivos, por meio do desenvolvimento de novos dispositivos capazes de obter interações específicas com os tecidos biológicos, conhecidos como scaffolds. O polímero de PLA (poliácido lático) apresenta-se de forma promissora para o uso como suporte temporário para substituição de tecidos por ser biodegradável, biocompatível e apresentar baixo custo. No entanto, sua característica hidrofóbica é uma das principais desvantagens da utilização desse polímero. Sendo assim, pesquisas atuais visam modificar a superfície desses dispositivos a fim de torná-los mais hidrofílicos. Este estudo teve como objetivo avaliar a modificação de superfície nos scaffolds de PLA, quimicamente tratados com o hidróxido de sódio (NaOH) para avaliar a adesão e viabilidade celular em scaffolds sobre o tratamento alcalino com NaOH. Foram utilizadas as técnicas de FTIR-ATR (Infravermelho com Transformada de Fourier de Reflectância Total Atenuada) e AFM (Microscopia de Força Atômica) para caracterização físico-química do material, ensaio de adesão e viabilidade celular pelo método fluorimétrico com o reagente resazurina. As análises de AFM e FTIR confirmaram a modificação da superfície do material pelo tratamento alcalino. Pela análise de adesão celular, concluiu-se que o tratamento não influenciou na adesão, mas foi mais eficaz na manutenção da viabilidade celular.

Use biological or synthetic scaffolds to conduct cellular events of the regenerative process constitute one of the major strategies in regenerative medicine area. Customized scaffolds built by additive manufacturing prove to be a great solution to this problem. Two desired features that aid in scaffold’s biocompatibility are the surface roughness and the geometric characteristic of the topography, usually achieved by a chemical procedure performed after printing. This research presented a modification on a 3D printer nozzle for directly generating an external topography in the extruded filaments, eliminating the need for an additional post-processing step. Cell morphology and viability on supports printed by the proposed and conventional method were evaluated in in vitro experiments and the new nozzle proved to be efficient in generating printed filaments with a degree of cytocompatibility superior to those obtained by conventional filaments. El uso de soportes biológicos o sintéticos para conducir eventos celulares del proceso regenerativo es una de las principales estrategias en el campo de la medicina regenerativa. Los soportes personalizados producidos por fabricación aditiva demuestran ser una gran solución a este problema. Dos características deseadas que ayudan en la biocompatibilidad de los soportes son la rugosidad de la superficie y la característica geométrica de su topografía, generalmente logradas por un procesamiento químico realizado después de la impresión. Esta investigación presenta la propuesta para obtener una boquilla de impresora 3D capaz de generar directamente una topografía externa sobre los filamentos extruidos, eliminando la necesidad de un paso adicional de postprocesado. La morfología celular y la viabilidad sobre soportes impresos por el método propuesto y convencional fueron evaluadas en experimentos in vitro y la nueva boquilla demostró ser eficiente en la generación de filamentos impresos con un grado de citocompatibilidad superior a los obtenidos por filamentos convencionales. A utilização de suportes biológicos ou sintéticos para a condução de eventos celulares do processo regenerativo constitui uma das principais estratégias na área da medicina regenerativa. Suportes customizados fabricados por manufatura aditiva provam ser uma ótima solução para este problema. Duas características almejadas que auxiliam na biocompatibilidade dos suportes são a rugosidade da superfície e a característica geométrica da sua topografia, geralmente alcançadas por um processamento químico realizado após a impressão. Esta pesquisa apresenta a proposta de obtenção de um bico de impressora 3D capaz de gerar diretamente uma topografia externa nos filamentos extrudados, eliminando a necessidade de uma etapa adicional de pós-processamento. A morfologia e viabilidade celular sobre suportes impressos pelo método proposto e convencional foram avaliadas em experimentos in vitro e o novo bocal mostrou-se eficiente em gerar filamentos impressos com grau de citocompatibilidade superior aos obtidos por filamentos convencionais.

Polylactic acid (PLA) is a biodegradable and bioresorbable biopolymer that has successfully been applied in biomedical and related fields. It is in the form of filaments, presenting different colors, with the purpose to be used in the three-dimensional printing (3D) technique. Thus, this work aimed to characterize five commercially available PLA filaments which were differentiated by color, as follows: blue (1), gray (2), transparent (3), orange (4) and natural (5) comparing to a pellet pattern. Thermal characterization was performed throughout simultaneous thermogravimetry (TG), derivative thermogravimetry (DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Significant differences in the enthalpies and temperatures of crystallization and melting indicated differences in crystallinity of the filaments corroborated by the XRD analysis. While analyzing using TG/DTG–DTA, significant differences in thermal stability were observed. The absorption spectroscopy in the infrared was also done to determine the chemical composition of the samples. Additionally, it was also observed the structure, size and roughness of the filaments using confocal microscopy building three-dimensional images. The oscillatory rheometer was employed to determinate the complex viscosity ( $$\eta ^*$$ ), the store modulus ( $$G'$$ ) and the loss modulus ( $$G''$$ ) as a function of frequency ( $$\omega$$ ). After conducting the characterizations, it was possible to compare the five types of PLA filaments and identify the best one to feature a functionalization in the future, which possibly enable them in tissue engineering applications. Results indicated that the blue filament fulfilled the best results regarding print quality, higher-temperature degradation and thermal stability, with the molar mass and viscosity superior to the other filaments.

Made available in DSpace on 2018-12-11T17:37:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-10-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Komagataeibacter rhaeticus, a bacterium isolated from Kombucha tea, was used to produce bacterial cellulose (BC) through its cultivation in a static sugarcane molasses (SCM) supplemented-culture medium (totally or partially), as an alternative carbon source. BC membranes were characterized by different physicochemical analysis using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), thermogravimetry analysis (TGA) and PeakForce quantitative nanomechanics atomic force microscopy (PeakForce (QNM-AFM)). FTIR, XRD and TGA results suggest great similarity among all membranes produced by distinct culture media. Although the glucose (F1) and SCM (F6) media presented the lowest BC yield, all SCM-supplemented culture media (from F2 to F5) showed BC yield values similar to the HS culture medium (F0). FEG-SEM analysis showed that as higher SCM concentrations on culture media higher dense nanofibers network could be prepared. Quantitative nanomechanical results obtained by AFM technique corroborate FEG-SEM analysis besides show smoother and more flexible BC membranes as a function of the increasing of the SCM concentrations. The modification of the carbon source of the culture medium with an important by-product of Brazilian agroindustry appears as a viable alternative to reduce cost of BC production (of up to 20.06%) besides increase the possibilities of industrial scale BC preparation. University of Araraquara – UNIARA Interdisciplinary Laboratory of Advanced Materials Centro de Ciências da Natureza – CNN Universidade Federal do Piauí – UFPI Institute of Chemistry – São Paulo State University – UNESP Group ‘Materials + Technologies’ (GMT) Department of Chemical and Environmental Engineering Faculty of Engineering Gipuzkoa University of the Basque Country (UPV/EHU), Plaza Europa 1 Faculty of Engineering Vitoria-Gasteiz University of the Basque Country (UPV/EHU), C/Nieves Cano 12 Laboratório de Pesquisa Desenvolvimento & Inovação, Apis Flora Ind. Coml. Ltda, Ribeirão Preto Institute of Chemistry – São Paulo State University – UNESP

Made available in DSpace on 2021-06-25T11:14:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-30 Photonic materials featuring simultaneous iridescence and light emission are an attractive alternative for designing novel optical devices. The luminescence study of a new optical material that integrates light emission and iridescence through liquid crystal self-assembly of cellulose nanocrystal-template silica approach is herein presented. These materials containing Rhodamine 6G were obtained as freestanding composite films with a chiral nematic organization. The scanning electron microscopy confirms that the cellulose nanocrystal film structure comprises multi-domain Bragg reflectors and the optical properties of these films can be tuned through changes in the relative content of silica/cellulose nanocrystals. Moreover, the incorporation of the light-emitting compound allows a complementary control of the optical properties. Overall, such findings demonstrated that the photonic structure plays the role of direction-dependent inner-filter, causing selective suppression of the light emitted with angle-dependent detection. Institute of Chemistry São Paulo State University (UNESP) Department of Physics University of Aveiro Biopolymers and Biomaterials Laboratory University of Araraquara Institute of Chemistry São Paulo State University (UNESP)

Made available in DSpace on 2021-06-25T11:12:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-04 Bacterial cellulose (BC) combined with organo-bridged porous silica nanoparticles offers potential opportunities to develop smart hybrid materials such as advanced drug delivery nanosystems. This work reports the preparation of bacterial cellulose membrane (BCM) and their modification by in situ methodology with the organo-bridged precursor 1,4-bis(triethoxysilyl)benzene (BTEB). BTEB was successfully incorporated into the BCM, and spherical hybrid silica nanoparticles with heterogeneous particle size (30-100 nm) and probably porous structure were formed and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared-attenuated total reflectance (FTIR-ATR), thermogravimetric analysis (TGA), and solid state nuclear magnetic resonance (NMR). We further combined solid-state NMR with dynamic nuclear polarization (DNP) to achieve sensitivity enhancement and to selectively enhance the NMR signal of the hydrophobic BTEB moieties on the BCM surface. This allowed us to get more detailed structural information about the BTEB-BCM multicomponent material. Institute of Chemistry São Paulo State University (UNESP) São Carlos Institute of Physics University of São Paulo, PO Box 369 ICGM Univ. Montpellier CNRS ENSCM Institut für Physikalische Chemie Technische Universität Darmstadt University of Araraquara (UNIARA) Institute of Chemistry São Paulo State University (UNESP)

One promising skin substitutes in the wound healing are the bacterial cellulose membranes (BCM). These biomaterials present nanostructures composed of microfibrils capable of forming three-dimensional pores that allow cell. In association with these biopolymers, several treatments are used, such as enrichment by growth factors and/or the application of photobiomodulation (PBM). Therefore, the aim of this study was to investigate the viability, proliferation and cytotoxicity of a BCM (culturing of Komagataeibacter xylinus), with or without FGF-2 in association with PBM therapy. In the characterization of BCM we saw that the membrane does not show great variations in pH and with the scanning electron microscopy it was possible to observe that the BCM has a denser and a porous side that allows the adhesion of fibroblasts, confirmed by histological staining and DAPI/Phalloidin. In vitro evaluation showed that the immunofluorescence (CaAM/EthD-1) for live and dead cells presented, in the groups with combined treatment at long-term of PBM and FGF-2, a greater quantity of live cells than with these isolated treatments and/or at short-term. However, in the short-term of combined treatment PBM and FGF-2 supplementation, fibroblasts and macrophages were more viable by Alamar Blue, in direct and indirect contact respectively. The comet assay did not show cytotoxicity for DNA damage in fibroblasts indirect contact with membrane extract. The results highlight the potential of association of FGF-2 supplementation with the application of PBM for use with BCM, due to its promoted increased cell density at long-term and improved viability in fibroblasts and macrophages at short-term.

Made available in DSpace on 2022-04-29T08:37:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 This study aimed to evaluate the antimicrobial and anti-biofilm activity of morin on polymicrobial biofilms and its cytotoxicity in controlled-release films and tablets based on gellan gum. Polymicrobial biofilms were formed from saliva for 48 h under an intermittent exposure regime to 1% sucrose and in contact with films or tablets of gellan gum containing 2 mg of morin each. Acidogenicity, bacterial viability, dry weight and insoluble extracellular polysaccharides from biofilms were evaluated. The cytotoxicity of morin was evaluated in oral keratinocytes. Morin released from the systems reduced the viability of all the microbial groups evaluated, as well as the dry weight and insoluble polysaccharide concentration in the matrix and promoted the control of acidogenicity when compared with the control group without the substance. Morin was cytotoxic only at the highest concentration evaluated. In conclusion, morin is an effective agent and shows antimicrobial and anti-biofilm activity against polymicrobial biofilms. Department of Morphology Pediatric Dentistry and Orthodontics School of Dentistry São Paulo State University–UNESP, SP Department of Dental Materials and Prosthodontics School of Dentistry São Paulo State University–UNESP, SP Department of Drugs and Pharmaceuticals School of Pharmaceutical Sciences São Paulo State University–UNESP, SP Biopolymers and Biomaterials Laboratory (BioPolMat) University of Araraquara–UNIARA, SP Department of Morphology Pediatric Dentistry and Orthodontics School of Dentistry São Paulo State University–UNESP, SP Department of Dental Materials and Prosthodontics School of Dentistry São Paulo State University–UNESP, SP Department of Drugs and Pharmaceuticals School of Pharmaceutical Sciences São Paulo State University–UNESP, SP

Made available in DSpace on 2022-04-29T08:32:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This study evaluates the efficiency of castor oil–based polyurethane foams for oil sorption S10 and S500, focusing on the influence of the pores’ size. Different foams were produced by varying the polyol: isocyanate ratio (1:0.3; 1:0.5; 1:1.0; 1:1.5; and 1:2.0). The physicochemical properties, morphology, density, and Hg porosity were determined. The sorption capacity was influenced by exposure time, oil viscosity, and concentration of the reagents, considering variations in the hydrophobicity, void content, and morphology. The results showed that the foam produced at an in the same mass proportion (PUC) has a higher sorption capacity in exposure time from 25 to 40 h due to higher void content and larger pore diameter size. It was observed that the lower viscosity of S10 diesel contributes to the higher sorption efficiency compared to S500 one. The Taguchi method corroborated the mentioned results, indicating a higher sorption trend by varying the reagent concentration and exposure times. Department of Materials and Technology School of Engineering (FEG) – CEP Sao Paulo State University (UNESP) Department of Energy School of Engineering (FEG) – CEP Sao Paulo State University (UNESP) Federal University for Latin American Integration (UNILA) Araraquara University – UNIARA Department of Mechanics and Energy UERJ Department of Materials and Technology School of Engineering (FEG) – CEP Sao Paulo State University (UNESP) Department of Energy School of Engineering (FEG) – CEP Sao Paulo State University (UNESP)

Bacterial cellulose (BC) is a natural polymer that has fascinating attributes, such as biocompatibility, low cost, and ease of processing, being considered a very interesting biomaterial due to its options for moldability and combination. Thus, BC-based compounds (for example, BC/collagen, BC/gelatin, BC/fibroin, BC/chitosan, etc.) have improved properties and/or functionality, allowing for various biomedical applications, such as artificial blood vessels and microvessels, artificial skin, and wounds dressing among others. Despite the wide applicability in biomedicine and tissue engineering, there is a lack of updated scientific reports on applications related to dentistry, since BC has great potential for this. It has been used mainly in the regeneration of periodontal tissue, surgical dressings, intraoral wounds, and also in the regeneration of pulp tissue. This review describes the properties and advantages of some BC studies focused on dental and oral applications, including the design of implants, scaffolds, and wound-dressing materials, as well as carriers for drug delivery in dentistry. Aligned to the current trends and biotechnology evolutions, BC-based nanocomposites offer a great field to be explored and other novel features can be expected in relation to oral and bone tissue repair in the near future., Facultad de Ciencias Exactas

Made available in DSpace on 2021-06-25T15:07:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) LNNano Defibrillation of bacterial cellulose by ultra-refining was efficient to release nanofibers (BCNF) which were spray dried with the matrices formers mannitol (MN), maltodextrin or hydroxypropylmethylcellulose. The best microsystem comprised the association of BCNF and MN, so the selected microparticles were loaded with diclofenac sodium or caffeine. Depending on the proportion of BCNF, the nanofibers collapse promoted by spray drying can occur onto surface or into microparticles core, leading to different release behaviors. Samples showed pH-dependent drug release, so the microsystem developed with the lowest BCNF concentration showed important trend to gastroresistance. Caffeine was spray dried as a free drug and for this reason it was devoid of any control over release rates. The set of results showed BCNF can be considered an interesting and potential pharmaceutical excipient for lipophilic drugs. Beyond that, BCNF association with MN can lead to novel enteric drug delivery systems based on natural polymers. Sao Paulo State Univ, Sch Pharmaceut Sci, BR-14800903 Araraquara, SP, Brazil Univ Araraquara, Lab Biopolymers & Biomat, BR-14801320 Araraquara, SP, Brazil Univ Sao Paulo, Sch Pharmaceut Sci Ribeirao Preto, BR-14040903 Ribeirao Preto, SP, Brazil So Paulo State Univ, Analyt Chem Dept, BR-14801970 Araraquara, SP, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, BR-14800903 Araraquara, SP, Brazil FAPESP: 2016/08435-4 FAPESP: 2018/25512-8 LNNano: SEM-C2-25397

Made available in DSpace on 2020-12-12T02:49:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The aims of this work were to evaluate the antibacterial and antiproliferative potential in vitro of the metal complex with 4-aminobenzoic acid (Ag-pABA) and a drug delivery system based on bacterial cellulose (BC-Ag-pABA). The Ag-pABA complex was characterized by elemental analysis, high resolution mass spectrometry and single-crystal X-ray diffraction techniques, which indicated a 1:2 metal/pABA composition plus a nitrate ion coordinated to silver by the oxygen atom, with the coordination formula [Ag (C7H7NO2)2(NO3)]. The coordination of pABA to the silver ion occurred by the nitrogen atom. The in vitro antibacterial activity of the complex evaluated by minimum inhibitory concentration assays demonstrated the effective growth inhibitory activity against Gram-positive, Gram-negative biofilm producers and acid-alcohol resistant Bacillus. The antiproliferative activities against a panel of eight tumor cells demonstrated the activity of the complex with a significant selectivity index (SI). The DNA interaction capacity and the Ames Test indicated the absence of mutagenicity. The BC-Ag-pABA composite showed an effective capacity of sustained release of Ag-pABA. The observed results validate further studies on its mechanisms of action and the conditions that mediate the in vivo biological effects using animal models to confirm its safety and effectiveness for treatment of skin and soft tissues infected by bacterial pathogens, urinary tract infections and cancer. University of Araraquara – UNIARA Institute of Chemistry University of Campinas – UNICAMP Faculty of Pharmaceutical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences Faculty of Medical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences FAPESP: , 2015/09833-0 CAPES: 001 FAPESP: 019/03049-7 FAPESP: 13/07276-1 FAPESP: 2014/06779-2 FAPESP: 2015/20882-3 FAPESP: 2016/07729-4 FAPESP: 2017/16278-9 FAPESP: 2017/19243-1 FAPESP: 2018/00163-0 FAPESP: 2018/02344-2 FAPESP: 2018/12062-4 FAPESP: 2018/12590-0 FAPESP: 2018/25512-8 CNPq: 300968/2016-7 CNPq: 407822/2018

Made available in DSpace on 2020-12-12T02:06:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The pursuit of biocompatible, breathable and skin-conformable wearable sensors has predominantly focused on synthetic stretchable hydrophobic polymers. Microbial nanocellulose (MNC) is an exceptional skin-substitute natural polymer routinely used for wound dressing and offers unprecedented potential as substrate for wearable sensors. A versatile strategy for engineering wearable sensing platforms is reported, with sensing units made of screen-printed carbon electrodes (SPCEs) on MNC. As-prepared SPCEs were used to detect the toxic metals cadmium (Cd2+) and lead (Pb2+) with limits of detection of 1.01 and 0.43 μM, respectively, which are sufficient to detect these metal ions in human sweat and urine. SPCEs functionalized through anodic pre-treatments were used for detecting uric acid and 17β-estradiol in artificial sweat, with detection limits of 1.8 μM and 0.58 μM, respectively. The electrochemical treatment created oxygen groups on the carbon surfaces, thus improving wettability and hydrophilicity. MNC was herein exploited as an adhesive-free, yet highly skin-adherent platform for wearable sensing devices that also benefit from the semi-permeable, non-allergenic, and renewable features that make MNC unique within the pool of materials that have been used for such a purpose. Our findings have clear implications for the developments on greener and more biocompatible but still efficient substrates and may pave the route for combining immunosensing devices with drug delivery therapies. São Carlos Institute of Physics University of São Paulo (USP) São Carlos Institute of Chemistry University of São Paulo (USP) Institute of Chemistry University of Campinas (UNICAMP), P.O. Box 6154 Biopolymers and Biomaterials Laboratory (BIOPOLMAT) University Center of Araraquara (UNIARA) Brazilian Nanotechnology National Laboratory (LNNano) Brazilian Center for Research in Energy and Materials (CNPEM) São Paulo State University (UNESP) Department of General and Inorganic Chemistry Rua Professor Francisco Degni, 55, Araraquara14800-060 São Paulo State University (UNESP) Department of General and Inorganic Chemistry Rua Professor Francisco Degni, 55, Araraquara14800-060 FAPESP: 2013/14262–7 FAPESP: 2015/01770–0 FAPESP: 2016/01919–6 FAPESP: 2016/06612–6 CNPq: 423952/2018-8

This study is focused on the development of a nanodevice for loading and release of 5-Fluorouracil (5-FU) with a view to improving its therapeutic efficiency, using as strategy the fabrication of a nanoconjugate through drug anchorage on the surface of carbon quantum dots (CQD). Several physicochemical and analytical techniques were employed to obtain information about materials morphology, structure, and optical properties. The results indicated that the interactions between both entities resulted in good physicochemical properties and photostability. Acid pH favored drug release, indicating a tendency to release 5-FU from 5-FU-CQD into the tumor microenvironment. The cytotoxicity of CQD and 5-FU-CQD nanoconjugate was evaluated against normal human lung fibroblast (GM07492A) and human breast cancer (MCF-7) cell lines. The CQD was non-toxic, indicating that these materials are biocompatible and can be used as a nanocarrier for 5-FU in biological systems. For the 5-FU-CQD nanoconjugate, it was observed a reduction in toxicity for normal cells compared to free 5-FU, suggesting that drug anchoring in CQD reduced drug-associated toxicity, while for cancer cells exhibited an antitumor effect equivalent to that of the free drug, opening perspectives for the application of this material in anticancer therapy.

Waterborne poly(urethane-urea)s (WPUUs) can be employed as a base for the preparation of new materials with novel properties and applications, such as hydrogels. In this work, sodium alginate (SA) was incorporated into WPUUs and their nanocomposites with TiO2 nanoparticles. The influence of the addition of SA and TiO2 nanoparticles on the final properties of WPUUs based hydrogels was investigated. It was proven that the hydrogen bonding interactions that took place between WPUU and SA strongly affected the final properties. The glass transition temperature and thermal stability of investigated hydrogels were affected depending on the soft segment composition. The prepared hydrogels exhibited swelling ability in an acidic medium. The porous structure of the prepared hydrogels was confirmed by the scanning electron microscope (SEM) measurements. In fact, the mechanical properties indicated an improvement in the compressive modulus with the increase of the SA content. Furthermore, the prepared hydrogels allowed the cell proliferation of human fibroblasts.

The purpose of tissue engineering is to repair, replace, and regenerate tissues and organs. For this aim, materials supports, as polylactic acid (PLA) are used. PLA is a thermoplastic polymer that presents biodegradability, biocompatibility and good processability. PLA scaffolds can accurately constructed by 3D printing. Then, the objectives of this work were to modify the hydrophobic surface of PLA scaffolds using oxygen plasma and to study the cell viability and proliferation. The characterization was done by AFM, contact angle, FTIR and studies of proliferation and cell viability. Results showed that the material acquired hydrophilic properties by the presence of oxygen reactive species and by contact angle decrease. It was also observed an increase in the surface roughness. We can conclude that although the surface modifications were effective and the PLA scaffolds were not cytotoxic, there were no improvements in the proliferation process with the studied osteo-1 lineage cells.

Made available in DSpace on 2020-12-12T02:34:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-24 In this work, we report the green synthesis of four luminescent organotin compounds 1–4 derived from amino acid Schiff bases (1: Naph-Trp-SnPh2, 2: Naph-Tyr-SnBu2, 3: Naph-Tyr-SnPh2, 4: Naph-Phe-SnPh2), obtained by ultrasound-assisted synthesis in short time (~20 min) and good yields (>95%). The molecular structure proposed in solution (1H and 119Sn NMR) was confirmed by X-ray diffraction study for compound 1 where the tin atom resides in trigonal bipyramid geometry. Luminescent silk fibroin scaffolds (SF 1–4) were elaborated with organotin compounds by freeze-drying technique. Photophysical properties of organotin compounds and scaffolds were obtained in solid state, observing bathochromic behaviors in tyrosine derived compounds, suggesting that the tyrosine produce supramolecular interactions across the –OH group that change the fluorescent properties. Scaffolds 1–4 were characterized by FTIR, XDR, TG/DTG, and SEM analysis. In addition, cytotoxic analysis of SF 1 presents high cellular viability, which could be applied as a scaffold in tissue engineering. Universidad Autónoma de Nuevo León Facultad de Ciencias Químicas, Ciudad Universitaria, Av. Universidad s/n Departamento de Química Centro de Investigación y de Estudios Avanzados del IPN, A. P. 14-740 São Carlos Institute of Physics – University of São Paulo (USP) Laboratory of Polymers and Biomaterials University of Araraquara (UNIARA) Department of Chemistry and Chemical Engineering Chalmers University of Technology Institute of Chemistry São Paulo State University - Unesp, CP355, Zip Code 14801-970 Institute of Chemistry São Paulo State University - Unesp, CP355, Zip Code 14801-970

Made available in DSpace on 2022-04-29T08:45:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Conventional orthodontic treatment with the use of stainless steel may be detrimental to oral health by promoting demineralizing lesions appearance and increasing adhesion and formation of bacterial biofilm,inducing the development of cavities. An alternative that has been researched to reduce the side effects of orthodontic treatment is the coating of materials with antimicrobial nanoparticles. Nanometric- sized particles increase their surface area and contact with the microbial membrane, consequently intensifying their bacteriostatic and bactericidal effect. In this work, hydrothermal synthesis, a “green” process was used to attach silver nanoparticles (AgNPs) to the surface of two different brands of orthodontic wires. The coated materials were analyzed for their physicochemical properties by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), which showed the distribution of AgNPs along the wires without modifying their properties. In the microbiological test, one of the brands showed a statistically significant difference in microbial adhesion and biofilm formation by Staphylococcus aureus and Streptococcus mutans. Results lead to the conclusion that antimicrobial orthodontic wires coated with silver nanoparticles through hydrothermal synthesis is a promising material for the improvement of orthodontic treatment. University of Araraquara Biopolymers and Biomaterials Laboratory University of Araraquara Orthodontics Post Graduation Course Dental School Department of Health Sciences Federal University of Piauí Research Center of Biodiversity and Biotechnology University of Volta Redonda Volta Redonda Biosmart Nanotechnology Nox Consultoria e Treinamento S/S LTDA

The combination of cellulosic materials and clays, such as Laponite, can provide composites with superior optical and mechanical properties compared to pristine cellulose. Synthetic clays can also be used as a host matrix for the immobilization of luminescent complexes, as the incorporated complexes may present enhanced emission quantum efficiency, photo and thermostability compared to the non-immobilized ones. In this way, we, herein, report the preparation of luminescent composites through the incorporation of a Eu(III) complex [Eu3+(tta)n] containing Laponite (Lap) into cellulose nanofibers (CNF). The thermogravimetry results show that the obtained CNF/Lap@[Eu3+(tta)n] films present higher thermal resistance than the CNF film. The Eu3+(tta)n species were found in the composite structure with preserved luminescence characteristics, and no leaching or degradation of the organic ligand was observed with the preparation of the composites.

The issues related to renewable energy sources is a matter of great worldwide appeal due to the increasing energy demand, instability in oil prices and environmental problems. In this context, the purpose of this study was to prepare self-assembled films of polyallylamine hydrochloride and poly (acrylic acid) supported onto bacterial cellulose membranes by a layer-by-layer approach with titanium dioxide (TiO2) nanoparticles and different concentrations of gold for application in hydrogen gas (H2) production by photocatalysis. The influence of the gold concentration and the presence and size of the gold nanoparticles (Au NPs), as well as the surface and thickness of the films on H2 production was investigated. The results showed that the film, prepared with a lower concentration of gold, presented the smallest Au NPs and, therefore, greater contact with the TiO2 nanoparticle surfaces, producing more H2. By analyzing the variation in all the experimental parameters used in the preparation of the films, it can be concluded that the best H2 production achieved was 29.12 μmol h−1 cm2.

Made available in DSpace on 2019-10-06T15:18:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-15 Abstract: This work reports the preparation of bacterial cellulose (BC) membranes with self-cleaning properties. SiO 2 @TiO 2 (anatase) spherical nanocomposites (around 50 nm in diameter) were prepared by sol–gel process and were successfully immobilized into the BC membrane, in wet and dry states, by post-grafting method, following two different methodologies: dip-coating and spin-coating. Characterization techniques included Raman scattering, energy-dispersive X-ray spectroscopies (EDS), thermogravimetric analyses (TGA), and scanning electron microscopy (SEM). The photocatalytic activity was higher in the BC membrane in the wet state, presenting a good self-cleaning performance (fast methyl violet 2B dye decomposition in 30 min). The functional BC membranes with self-cleaning properties also presented high resistance to washing, high chemical stability, and the original features (color and texture) were maintained. [Figure not available: see fulltext.]. Institute of Chemistry São Paulo State University UNESP Institut Charles Gerhardt Montpellier UMR5253 CNRS-ENSCM-UM University of Araraquara – UNIARA Brazilian Nanotechnology National Laboratory (LNNano) Brazilian Center for Research in Energy and Materials (CNPEM) Institute of Chemistry São Paulo State University UNESP

Made available in DSpace on 2018-11-26T17:42:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) In this work, for the first time bacterial cellulose (BC) hydrogel membranes were used for the fabrication of antimicrobial cellulosic nanocomposites by hydrothermal deposition of Cu derivative nanoparticles (i.e. Cu(0) and CuxOy species). BC-Cu nanocomposites were characterized by FTIR, SEM, AFM, XRD and TGA, to study the effect of hydrothermal processing time on the final physicochemical properties of final products. XRD result show that depending on heating time (3-48 h), different CuxOy phases were achieved. SEM and AFM analyses unveil the presence of the Cu(0) and copper CuxOy nanoparticles over BC fibrils while the surface of 3D network became more compact and smother for longer heating times. Furthermore, the increase of heating time placed deleterious effect on the structure of BC network leading to decrease of BC crystallinity as well as of the on-set degradation temperature. Notwithstanding, BC-Cu nanocomposites showed excellent antimicrobial activity against E. coli, S. aureus and Salmonella bacteria suggesting potential applications as bactericidal films. Univ Fed Piaui, Dept Quim, Campus Minist Petronio Portela, BR-64049550 Teresina, PI, Brazil Univ Estadual Paulista, Inst Quim Araraquara, Dept Quim Geral & Inorgan, Rua Prof Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil Centro Univ Araraquara, Lab Biopolimeros & Biomat BIOPOLMAT, Rua Carlos Gomes,1217, BR-14801320 Araraquara, SP, Brazil Univ Basque Country UPV EHU, Dpto Ingn Quim & Medio Ambiente, Escuela Politecn Donostia San Sebastian, Pza Europa 1, Donostia San Sebastian 20018, Spain Univ Luterana Brasil, Programa Posgrad Genet & Toxicol Aplicada, Ave Farroupilha,8001,Predio 01, BR-92450900 Canoas, RS, Brazil Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Paulista, Inst Quim Araraquara, Dept Quim Geral & Inorgan, Rua Prof Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil FAPESP: 2015/ 09833-0 FAPESP: 2016/06612-6

The reuse of acai seeds is an organic approach for valorizing biomass, encouraging the public policies of circular economy, which reduces the human impact on the production chain processes. This research proposes an alternative for acai seed as a filler in castor oil-based polyurethane, obtaining eco-sorbent to evaluate the sorption capacity for another impactful food industry by-product: waste cooking oil (WCO). Eco-sorbents were obtained with castor oil based-polyol and isocyanate (MDI) by mass mixing equal to 1:1 (OH:NCO), reinforced with acai seed residue (5–20 wt%). The samples were characterized by techniques scanning electron microscopy (SEM), optical microscopy (OM), apparent density, contact angle, infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Sorption capacity and efficiency were evaluated as a function of the fiber content, with tests performed in times of 30–180 s in two systems: oil and oil/water. The results showed that the eco-sorbents had a hydrophobic nature (θ > 98.3°) and macroporous morphology (pore size from 152 to 119 μm), which allowed the adsorption of residual cooking oil by the porous structure. The kinetics study showed that the sample with greater fiber content (15% wt.) reached the equilibrium in a short time compared to the neat PU for the oil system, with a sorption capacity of 9.50 g g−1 in the first 30 s. For the oil/water system, an opposite behavior could be observed, with a sorption capacity of 9.98 g g−1 in the 150 s equilibrium time. The Langmuir isotherm model presented a maximum adsorption capacity of 10.42 g g−1. However, the Freundlich isotherm model had a better fit to the experimental data with R2 (0.97) and lower chi-square (0.159), showing favorable adsorption (n = 1.496). Thus, it was proved that the weak interactions (connection H) and the binding energy of the predominant physisorption for the oil/water system. Thus, developed eco-sorbents are an excellent option for the sorption of WCO.

Made available in DSpace on 2021-06-25T11:03:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This paper reports on the synthesis and characterization of gel-like calcium polyphosphate coacervates (Ca–PPCs) with three different [P]:[Ca] ratios as new matrixes for drug release. Caffeine and chlorhexidine were used as model drugs, showing encapsulation efficiency of up to 95.4% and 70.4%, respectively. Based on the correlation coefficient (r2) values, different in vitro release behaviors were determined. While the caffeine release followed the Weibull model, the chlorhexidine release was best described by the Korsmeyer-Peppas model. The caffeine-loaded coacervate sample with the highest Ca2+ concentration (CAFPCa0.5) showed the highest incorporation and a total drug release within 720 min. The Ca-PPC-drug interactions were evaluated by infrared and Raman spectroscopies. The Ca2+ concentration, drug molecule size and intermolecular drug/matrix interactions determined the incorporation and release of drugs in the polyphosphate coacervates. High calcium concentration led to a Ca-PPC with small and tight “cage-like” structure that better incorporated caffeine molecules because of their 4.3 times smaller size compared to chlorhexidine. In addition, caffeine interacted through van der Waals' forces with polyphosphate and its release from the coacervates was most likely to occur in relation to chlorhexidine, which interacted with the coacervates through hydrogen bonding. Thus, the calcium polyphosphate coacervates loaded with the proposed drugs can be competitive and promising as drug delivery systems. Institute of Chemistry São Paulo State University -UNESP BioSmart Nanotechnology LTDA Incubadora Municipal de Araraquara-SP, Av. Jorge Fernandes de São Mattos, 311 University of Araraquara UNIARA Laboratório de Biopolímeros e Biomateriais University of Coimbra Faculty of Pharmacy Institute of Chemistry São Paulo State University -UNESP FAPESP: 2013/07793–6 FAPESP: 2018/24735–3 FAPESP: 2018/25512–8 CNPq: 407822/2018–6

The present article describes the synthesis and biological studies in vitro of a novel silver complex with furosemide (Ag-FSE). Elemental, thermal and mass spectrometric analysis indicated a 1:1 metal/ligand composition, with the molecular formula AgC 12 H 10 ClN 2 O 5 S. Infrared and nuclear magnetic resonance studies suggest coordination of the ligand to the silver ion by the oxygen atoms of the carboxylate group. Additional Density Functional Theory (DFT) studies led to the proposition of the structure of the Ag-FSE complex. The antibacterial activities of the complex were primarily evaluated by antibiogram assays using the disc diffusion method and minimum inhibitory concentrations (MIC). Moreover, the mutagenicity of the complex was also evaluated to ensure that it is safe for subsequent application. The Ag-FSE complex has shown a significant in vitro antibacterial activity against Gram-positive Staphylococcus aureus (ATCC 25923), Gram negative Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853), and yeast Candida albicans (ATCC 90028). The absence of a mutagenic activity of Ag-FSE against Salmonella Typhimurium bacterial strains in the Ames assay is an extremely important finding for its future use as a drug in medicine.

Made available in DSpace on 2018-11-28T09:04:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A colorimetric method based on silver nanoparticles was developed for the determination of melamine in milk. Silver nanoparticles were synthesized without any stabilizer, using sodium borohydride as the reducing agent. Optimization of the variables for the formation of the nanoparticles was performed by factorial design, resulting in stable colloidal silver nanoparticles with a mean diameter of 14.0. 2.7 nm. Spectrophotometric measurements performed at 475 nm showed a linear range from 0.033 to 1.50 mg L-1 of melamine with limits of detection and quantification of 0.009 and 0.031 mg L-1, respectively. The method provided highly sensitive determination of melamine in milk. Univ Estadual Paulista, Inst Quim, R Prof Francisco Degni 55,POB 355, BR-14800900 Sao Paulo, Brazil Univ Estadual Paulista, Inst Quim, R Prof Francisco Degni 55,POB 355, BR-14800900 Sao Paulo, Brazil

Made available in DSpace on 2018-12-11T17:23:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-11-05 A strain isolated from Kombucha tea was isolated and used as an alternative bacterium for the biosynthesis of bacterial cellulose (BC). In this study, BC generated by this novel bacterium was compared to Gluconacetobacter xylinus biosynthesized BC. Kinetic studies reveal that Komagataeibacter rhaeticus was a viable bacterium to produce BC according to yield, thickness and water holding capacity data. Physicochemical properties of BC membranes were investigated by UV–vis and Fourier transform infrared spectroscopies (FTIR), thermogravimetrical analysis (TGA) and X-ray diffraction (XRD). Additionally, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were also used for morphological characterization. Mechanical properties at nano and macroscale were studied employing PeakForce quantitative nanomechanical property mapping (QNM) and dynamic mechanical analyzer (DMA), respectively. Results confirmed that BC membrane biosynthesized by Komagataeibacter rhaeticus had similar physicochemical, morphological and mechanical properties than BC membrane produced by Gluconacetobacter xylinus and can be widely used for the same applications. Laboratório de Biopolimeros e Biomateriais (BIOPOLMAT) Centro Universitário de Araraquara, Araraquara Group ‘Materials + Technologieś (GMT) Department of Chemical and Environmental Engineering Engineering College of Gipuzkoa University of the Basque Country (UPV/EHU), Plaza Europa 1 Laboratório de Pesquisa Desenvolvimento & Inovação Apis Flora Ind. Coml. Ltda, Ribeirão Preto Institute of Chemistry-São Paulo StateUniversity-UNESP Institute of Chemistry-São Paulo StateUniversity-UNESP

Bacterial cellulose (BC) produced by some bacteria, among them Gluconacetobacter xylinum, which secrets an abundant 3D networks fibrils, represents an interesting emerging biocompatible nanomaterial. Since its discovery BC has shown tremendous potential in a wide range of biomedical applications, such as artificial skin, artificial blood vessels and microvessels, wound dressing, among others. BC can be easily manipulated to improve its properties and/or functionalities resulting in several BC based nanocomposites. As example BC/collagen, BC/gelatin, BC/Fibroin, BC/Chitosan, etc. Thus, the aim of this review is to discuss about the applicability in biomedicine by demonstrating a variety of forms of this biopolymer highlighting in detail some qualities of bacterial cellulose. Therefore, various biomedical applications ranging from implants and scaffolds, carriers for drug delivery, wound-dressing materials, etc. that were reported until date will be presented.

Inorganic matrices and biopolymers have been widely used in pharmaceutical fields. They show properties such as biocompatibility, incorporation capacity, and controlled drug release, which can become more attractive if they are combined to form hybrid materials. This work proposes the synthesis of new drug delivery systems (DDS) based on magnesium phyllosilicate (Talc) obtained by the sol&ndash, gel route method, the biopolymer chitosan (Ch), and the inorganic-organic hybrid formed between this matrix (Talc + Ch), obtained using glutaraldehyde as a crosslink agent, and to study their incorporation/release capacity of amiloride as a model drug. The systems were characterized by X-ray diffraction (XRD), Therma analysis TG/DTG, and Fourier-transform infrared spectroscopy (FTIR) that supported the DDS&rsquo, s formation. The hybrid showed a better drug incorporation capacity compared to the precursors, with a loading of 55.74, 49.53, and 4.71 mg g&minus, 1 for Talc + Ch, Talc, and Ch, respectively. The release assays were performed on a Hanson Research SR-8 Plus dissolver using apparatus I (basket), set to guarantee the sink conditions. The in vitro release tests showed a prolongation of the release rates of this drug for at least 4 h. This result proposes that the systems implies the slow and gradual release of the active substance, favoring the maintenance of the plasma concentration within a therapeutic window.

Made available in DSpace on 2020-12-12T02:23:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Abstract: The production of films and coatings from onion (Allium cepa L.) to be applied as packaging is attractive, due to its high nutritional and therapeutic value. Also, it can collaborate to minimize environmental impacts caused by the improper disposal of products made from plastics. However, despite it being an innovative and novel proposal, onion films for the development of edible packaging should be evaluated before being considered nontoxic and safe for human consumption. Thus, the objective of the present study was to elucidate the cytotoxic and mutagenic profile of eluates of polymer films of Allium cepa L. obtained by the casting process and to verify their safety for commercial purposes. The analysis of cellular viability demonstrated greater cytotoxicity for unwashed hydrothermally treated pulp (HTP) than for films of washed hydrothermally treated pulp (W-HTP). Regarding the mutagenic activity, the HTP and W-HTP films were not able to statistically increase the frequencies of the biomarkers for chromosome damage (micronucleus test) at the tested concentrations. However, the HTP films showed signs of mutagenicity in the Ames test (gene mutations), suggesting caution in their use. The detection of genotoxicity is highly recommended in order to avoid the risk of genotoxic exposure to mutagens and carcinogens. In conclusion, the absence of mutagenicity and cytotoxicity observed in this study is extremely relevant, because it provides support for toxicogenic properties of the Allium cepa films with promising applicability in the food industry. Practical Application: The bioplastics made from onion bulbs are multifunctional materials, which requires safety profile assessment. The results of the mutagenicity and cytotoxicity tests suggests that especially the W-HTP films are harmless, supporting at the first level of evidence, its safety potential to be used in the food industry (food films), biodegradable packaging, and biomaterials (substrates for drug delivery system). UNIARA—Univ. of Araraquara Dept. of Biological Sciences and Health São Paulo State Univ. (UNESP) Inst. of Chemistry São Paulo State Univ. (UNESP) Inst. of Chemistry FAPESP: 2017/16278-9

Made available in DSpace on 2019-10-06T16:50:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Natural polymers templates capable to maneuver the growth and spatial distribution of functional nanoparticles have been furthering the development of a new generation of sustainable and versatile materials. Pure cellulose nanofibrils, biosynthesized by bacteria, naturally deliver a 3D interconnected network of lightweight, foldable and sustainable matrices. Cellulose membrane is an exceptional biodegradable and biocompatible and high mechanical strength substrate with a native fibrous structure that can be easily applied as a structure-directing host to produce nanosized materials with optical, electrical or magnetic properties. In this work, we investigated the preparation of magnetic membranes by using bacterial cellulose nanofibers to control the growth of molecule-based magnetic nanoparticles such as Prussian Blue analogs. Magnetic Cobalt–Prussian Blue (CoHCEFe) nanoparticles were synthesized in situ by hydrothermal method through a diffusion-limited precipitation process onto a bacterial cellulose nanofiber network. Scanning electron microscopy and atomic force microscopy clearly unveiled a homogeneous distribution of immobilized COHCEFe crystalline nanoparticles whose size ranges from 94 to 70 nm as a function of nanoparticle content (up 28 wt%). Magnetic force microscopy showed that these nanometric COHCEFe crystalline nanoparticles well dispersed in BC fibers network respond to the magnetic field applied to the MFM-tip. This nano/nano association approach can provide functionally advanced materials for application in catalysis, adsorption of radionuclides, energy generation, data storage, biosensing, optical and magnetic devices. Laboratório de Biopolímeros e Biomateriais (BIOPOLMAT) Universidade de Araraquara São Carlos Institute of Physics University of São Paulo Institute of Chemistry São Paulo State University UNESP Group `Materials + Technologies´ (GMT) Department of Chemical and Environmental Engineering Faculty of Engineering Gipuzkoa University of the Basque Country (UPV/EHU), Plaza Europa 1 Faculty of Engineering Vitoria-Gasteiz University of the Basque Country (UPV/EHU), C/Nieves Cano 12 Institute of Chemistry São Paulo State University UNESP

Optical devices are today based mainly on glass or synthetic polymers, which hinders their use in biological interfaces owing to the lack of biocompatibility and biodegradability. This is why synthetic plastics are progressively being replaced by their bioplastic counterparts, thus bringing new challenges associated with processability, environmental sustainability, and large-scale fabrication of successful products. Natural polymers or biopolymers are fascinating self-assembled block polymer structures of nearly unlimited and inexpensive renewable resources, now finding applications in various fields, including optics. The ability to control the assembly and conformation of natural polymers into optical quality solutions and films brings the opportunity to revisit their application usually restricted to packaging and medical area. Of particular importance is to combine these polymers with metallic nanoparticles whose tunable localized surface plasmon resonance can be exploited in engineering composite materials with enhanced optical properties. The combined advantages also make them an ideal integration platform to foster biodegradable, bioresorbable, environmentally friendly, and sustainable electronic and optoelectronic devices. This chapter provides comprehensive coverage of advances and trends of how natural polymers and natural polymer-metallic nanoparticle composites have been explored for developing optical devices such as colorimetric sensors, transparent electrodes, optical waveguides, and light amplification devices. Examples will be given of optical composites made of chitin and chitosan, bacterial cellulose, silk fibroin, and DNA, with special emphasis on the challenges and ongoing efforts to fabricate useful devices.

Made available in DSpace on 2020-12-12T02:23:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 A new biopolymer obtained from onion pulp (Allium cepa L.) was employed to produce a sustainable substrate for flexible organic light-emitting diodes (FOLEDs). Indium tin oxide (ITO) and SiO2 thin films were deposited by rf-magnetron sputtering onto these biosubstrates to obtain flexible, transparent, and conductive anodes, on top of which FOLEDs were produced. This new biomaterial exhibits an optical transparency of 63% at 550 nm. ITO films were optimized by varying rf power during deposition onto the biopolymers, and their electrical properties are comparable to the those of ITO grown on top of rigid substrates: a carrier concentration of -3.63 × 1021 cm-3 and carrier mobility of 7.72 cm2 V-1 s-1 for the optimized film. Consequently, the sheet resistance and resistivity of this ITO film were 8.92 ω sq-1 and 2.23 × 10-4 ω cm, respectively, hence allowing the production of FOLEDs. The A. cepa L. based FOLED was fabricated using CuPc, β-NPB, and Alq3 as organic layers, and it exhibited a maximum luminance of about 2062 cd m-2 at 16.6 V. The current efficiency reached a maximum value of 2.1 cd A-1 at 85.3 mA cm-2. The obtained results suggest the possibility to use these substrates for innovative biocompatible applications in optoelectronics, such as photodynamic therapy. Grupo de Nanociência e Nanotecnologia (NANO) Departamento de Física Universidade Federal de Juiz de Fora (UFJF) Laboratório de Biopolímeros e Biomateriais (BIOPOLMAT) Departamento de Química Universidade de Araraquara (UNIARA) Instituto de Física de São Carlos Universidade de São Paulo (USP) Instituto de Química Universidade Estatual Paulista Júlio de Mesquita Filho (UNESP) BioSmart Nanotechnology Laboratório de Optoeletrônica Molecular (LOEM) Departamento de Física Pontifícia Universidade Católica Do Rio de Janeiro (PUC-Rio) Departamento de Química Pontifícia Universidade Católica Do Rio de Janeiro (PUC-Rio) Instituto de Química Universidade Estatual Paulista Júlio de Mesquita Filho (UNESP)

Made available in DSpace on 2019-10-06T16:49:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 In this work, high transparent bacterial cellulose (HTBC) biocompatible membranes were produced to be used as substrates in organic light-emitting diodes (OLEDs). These multifunctional membranes are based on bacterial cellulose (BC) and an organic–inorganic sol, composed of boehmite (Boe) nanoparticles and epoxi modified siloxane (GTPS). In order to be used as substrates, BC/Boe-GPTS membranes were covered with silicon dioxide (SiO 2 ) and indium tin oxide (ITO) thin films deposited at room temperature using radio frequency (RF) magnetron sputtering. Visible light transmission improves to 88%, instead of 40% previously achieved. The electrical properties for HTBC/SiO 2 /ITO substrate shows that the ITO deposited films are n-type doped semiconductors with resistivity of 2.7 × 10 −4 Ω cm, carrier concentration of − 1.48 × 10 21 cm −3 , and mobility of 15.2 cm 2 V −1 s −1 . These values are comparable to those of commercial ITO deposited onto glass substrates. After the characterization of the HTBC film, we used it as a substrate for the fabrication of a small molecule organic light-emitting diode OLED. The maximum efficiencies obtained were 1.95 cd/A and 1.68 cd/A for the reference OLED and the HTBC OLED, respectively. The HTBC OLED efficiency is then around 86% of the standard ITO-based OLED. This is clearly a good improvement, since previous BC-based simple architecture devices without Boe-GPTS have an efficiency 50% smaller than that of the standard OLED. Laboratório de Eletrônica Orgânica Departamento de Física Universidade Federal de Juiz de Fora UFJF Divisão de Metrologia de Materiais (DIMAT) Inmetro Laboratório de Biopolímeros e Biomateriais – BioPolMat Universidade de Araraquara (Uniara) Departamento de Química Faculdade de Filosofia Ciências e Letras de Ribeirão Preto Universidade de São Paulo Instituto de Química Universidade Estadual Paulista UNESP Laboratório de Optoeletrônica Molecular Departamento de Física Pontifícia Universidade Católica do Rio de Janeiro PUC-Rio Instituto de Química Universidade Estadual Paulista UNESP