A hydrogel from cellulose acetate cross linked with ethylenediaminetetraacetic dianhydride (HAC-E... more A hydrogel from cellulose acetate cross linked with ethylenediaminetetraacetic dianhydride (HAC-EDTA) was synthesized by our research group, and submitted to characterization and biological tests. Cytocompatibility analysis was performed by confocal microscopy using human adipocyte derived stem cells (ASCs). The FTIR analysis showed characteristic bands of cellulose acetate and hydroxyl groups and the tensile tests evidence that HAC-EDTA present a Young's modulus of 643.7 MPa. The confocal analysis revealed that there was cell growth at the surface of HAC-EDTA. After one day of culture the cells presented spherical morphology, which may be caused by stress of the sequestration of Ca<sup>2+</sup> and Mg<sup>2+</sup> ions at the cell medium by HAC-EDTA, as demonstrated by ICP-MS. However, after seven days and 14 days of culture, the cells present fibroblastoid morphology, phenotype expected by this cellular type. The results give efforts to indicate this ne...
The state-of-the-art sustained drug delivery systems are related to features to improve pharmacol... more The state-of-the-art sustained drug delivery systems are related to features to improve pharmacological transport through a controlled ratio between drug release and the desired therapeutic effect. Microspheres of biodegradable polymers, such as poly(lactic-co-glycolic acid) (PLGA), play an important role in these approaches, directing the release in a specific region of interest. In this way, the encapsulation of doxycycline (DOX) as a microbial agent turns the PLGA microspheres into a potential device for the treatment of topic oral diseases. Thus, this work aimed to produce DOX-loaded PLGA microspheres and see how they interfered with mesenchymal stem cell viability and in the sustained release in antimicrobial assays. Scanning electron microscopy showed the spherical microstructured pattern, revealing assorted sized distribution, with major diameters ranging 1–3 µm. The encapsulation efficiency presented a mean of 80% in both methods to obtain the microspheres (sonication and ma...
A recent and quite promising technique for bone tissue engineering is the 3D printing, peculiarly... more A recent and quite promising technique for bone tissue engineering is the 3D printing, peculiarly regarding the production of high-quality scaffolds. The 3D printed scaffold strictly provides suitable characteristics for living cells, in order to induce treatment, reconstruction and substitution of injured tissue. The purpose of this work was to evaluate the behavior of the 3D scaffold based on Poly(L-co-D,L lactic acid-co-Trimethylene Carbonate) (PLDLA-TMC), which was designed in Solidworks™ software, projected in 3D Slicer™, 3D printed in filament extrusion, cultured with mesenchymal stem cells (MSCs) and tested in vitro and in vivo models. For in vitro study, the MSCs were seeded in a PLDLA-TMC 3D scaffold with 600 μm pore size and submitted to proliferation and osteogenic differentiation. The in vivo assays implanted the PLDLA-TMC scaffolds with or without MSCs in the calvaria of Wistar rats submitted to 8 mm cranial bone defect, in periods of 8–12 weeks. The results showed that...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2020
Introducao: Ao longo das decadas, com o melhor conhecimento da etiologia das doencas periodontais... more Introducao: Ao longo das decadas, com o melhor conhecimento da etiologia das doencas periodontais, foram desenvolvidas tecnicas de tratamento efetivo. O uso de agentes antimicrobianos, tanto sistemicos como locais, sao coadjuvantes essenciais ao tratamento mecânico. A doxiciclina (DOX), uma tetraciclina semi sintetica, e mais vantajosa que a tetraciclina por exibir maior absorcao bucal, tem meia-vida mais prolongada e mostra uma melhor solubilidade lipidica, o que e importante para a sua acao antibacteriana. Mesmo com o bom desempenho da doxiciclina, necessita-se de um veiculo que permita a liberacao e disposicao da mesma, no meio subgengival, por um periodo prolongado. Assim, o poli (L-Acido Latico-co-Acido Glicolico) (PLGA) representa um tipo de microparticulado polimerico que oferece uma abordagem alternativa para a liberacao de drogas, devido a sua biocompatibilidade, nao imunogenicidade, nao toxicidade, biodegradabilidade, metodos de preparacao simples e estabilidade fisicoquim...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2019
INTRODUCAO : O crescimento osseo, em decorrencia de fraturas, e acelerado atraves do uso de enxer... more INTRODUCAO : O crescimento osseo, em decorrencia de fraturas, e acelerado atraves do uso de enxertos osseos autogenos ou alogenicos. O primeiro e materialmente limitado e causa morbidade e irregularidades de contorno, e o segundo, esta refem de respostas imunes mediadas por celulas. Dessa forma, estudos com biomaterias, em especial os polimeros sinteticos, aptos para implantes osseos, sao alvos da engenharia de tecidos. Entre eles esta o biomaterial Poli(Lco-D,L acido latico-co-Trimetileno Carbonato), PLDLA-TMC, que apresenta algumas particularidades vantajosas para area medica, como o fato de ser um arcabouco poroso, com a possibilidade de induzir a diferenciacao osteogenica a partir de celulas mesenquimais. OBJETIVOS : Avaliar os efeitos do arcabouco PLDLA-TMC sobre a viabilidade da cultura de celulas mesenquimais e na diferenciacao osteoblastica. METODOS : O PLDLA-TMC foi sintetizado em forma de arcaboucos porosos 3D de 8mm de diâmetro, utilizados para a proliferacao e diferencia...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2018
Introducao : Na atencao basica ao paciente queimado, o manejo dessas lesoes consiste atualmente n... more Introducao : Na atencao basica ao paciente queimado, o manejo dessas lesoes consiste atualmente na limpeza da ferida com agua, clorexidina degermante e administracao de agentes topicos bactericidas e profilaticos. Dessa forma, as praticas curativas utilizadas atualmente nao promovem, em grande parte, a regeneracao e cicatrizacao tecidual, funcionando apenas como barreiras fisicas e biologicas. Portanto, uma alternativa interessante ao atual tratamento de queimaduras e a utilizacao de biomateriais polimericos associados a moleculas indutoras, por serem biocompativeis, biodegradaveis, alem de minimizarem as reacoes adversas no organismo. Objetivos : Producao de um biomaterial que funcione como curativo para queimaduras de segundo grau, a base de POLI(ALCOOL VINILICO)/QUITOSANA/COLAGENO. Este material foi avaliado quanto a sua capacidade de induzir a regeneracao de queimaduras atraves de analises histologicas e morfometricas. Metodos : Para a realizacao do estudo, foram utilizados 40 r...
INTRODUCAO : A associacao de polimeros biocompativeis e biorreabsorviveis com celulas-tronco mese... more INTRODUCAO : A associacao de polimeros biocompativeis e biorreabsorviveis com celulas-tronco mesenquimais (CTMs) tem sido utilizada como alternativa de tratamento em lesoes e defeitos osseos, potencializando resultados e reduzindo custos. OBJETIVOS : Este projeto buscou analisar, por meio de tecnicas histologicas, o efeito da implantacao de um arcabouco de terpolimero poli (L-co-D,L acido latico-co-Trimetileno Carbonato) (PLDLA-TMC), cultivado com CTMs, na regeneracao de defeito osseo de tamanho critico confeccionado na calvaria de ratos Wistar, no intuito de potencializar a capacidade osteogenica e osteo reparadora do implante do biomaterial. METODOLOGIA : Foram utilizados 36 animais, divididos em 2 grupos conforme o tempo dos implantes (8 semanas e 12 semanas). Cada grupo, por sua vez, foi subdividido em 3 subgrupos iguais: controle negativo, defeito com PLDLA-TMC e defeito com PLDLA-TMC associado a CTMs. Por fim, os animais foram sacrificados e as amostras de suas calotas cranian...
O uso do poli(alcool-vinilico) (PVA) com nanoparticulas de prata (NpAg) como curativo cutâneo aum... more O uso do poli(alcool-vinilico) (PVA) com nanoparticulas de prata (NpAg) como curativo cutâneo aumentou. Na forma de membrana, o PVA atua como analogo epidermico, protegendo a lesao da desidratacao e mantendo-a umida. Ja o arcabouco de gelatina (gel) e acido hialuronico (AH) atua como derme substituta. As celulas-tronco mesenquimais derivadas de tecido adiposo humano (CTMs-TAh) podem ser cultivadas no arcabouco de gel-AH para produzirem substâncias que auxiliam na regeneracao dermica. Este estudo analisou a morfologia e citocompatibilidade do dispositivo PVA-NpAg/gelAH/CTM-TAh in vitro e investigou a ocorrencia de regeneracao dermica em lesao dorsal de espessura total em ratos Wistar. A morfologia do dispositivo foi analisada por microscopia eletronica. O ensaio de citocompatibildade foi realizado por microscopia confocal. Dividiu-se 60 ratos em 4 grupos: controle (somente lesao), PVA-NpAg, PVANpAg/gel-AH e PVA-NpAg/gel-AH/CTM-TAh. Eles foram sacrificados apos 14 e 28 dias e a pele d...
Introducao : A utilizacao de plantas e uma alternativa de baixo custo as drogas sinteticas utiliz... more Introducao : A utilizacao de plantas e uma alternativa de baixo custo as drogas sinteticas utilizadas no tratamento de queimaduras. Dentre as diversas plantas medicinais, a aroeira (Schinus terebinthifolius Raddi) demonstra ter propriedades anti-inflamatorias, antimicrobianas e antioxidantes que lhe atribuem um alto potencial cicatrizante [1]. Objetivos : Avaliar in vivo a acao cicatrizante da aroeira associada a membranas do terpolimero poli (L-co-D,L acido latico-co-TMC) (PLDLA-co-TMC) como matriz polimerica. Justificativas : Encontrar alternativas de baixo custo para o tratamento de queimaduras considerando que os curativos atuais para o tratamento desse tipo de lesao sao caros e nao estao disponiveis para uso no SUS. Metodologia : 30 ratos Wistar foram separados em grupos controle negativo e positivo, e grupo tratado. Apos anestesia foram submetidos a lesao termica por escaldo e apos 7 e 14 dias foram sacrificados e a pele lesionada foi retirada e processada para analise histolo...
Bioreactor systems that allow the simulation of in vivo variables in a controlled in vitro enviro... more Bioreactor systems that allow the simulation of in vivo variables in a controlled in vitro environment, were a great advance in the field of tissue engineering. Due to the dynamic-mechanical features that some tissues present, 3D-engineered constructs often do not exhibit the biomechanical properties of these native tissues. Thus, a successful approach must not only achieve tissue repair but also restore its function after injury. Here, we describe a method to improve cell activity in 3D scaffolds in a dynamic bioreactor system through the application of mechanical compression and fluid flow for tissue engineering approaches.
The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. Howev... more The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. However, the use of this hydrogel is challenging due to its favorable properties for microbiota growth. The association with silver nanoparticles (AgNPs) as an antimicrobial agent turns the match for PVA as a dressing, as it focuses on creating a physical barrier to avoid wound dehydration. When associated with extracellular components, such as the collagen matrix, the device obtained can create the desired biological conditions to act as a skin substitute. This study aimed to analyze the anti-microbiological activity and the in vitro and in vivo responses of a bilaminar device of PVA containing AgNPs associated with a membrane of collagen–hyaluronic acid (col-HA). Additionally, mesenchymal stem cells were cultured in the device to evaluate in vitro responses and in vivo immunomodulatory and healing behavior. The device morphology revealed a porous pattern that favored water retention and in ...
Nanomechanical biosensors based on atomic force microscopy (AFM) cantilevers have garnered consid... more Nanomechanical biosensors based on atomic force microscopy (AFM) cantilevers have garnered considerable attention. AFM cantilevers are devices that can detect a target either via a surface functionalization process based on immobilization through molecular adsorption, or through the selective chemical binding of a specific molecule, transforming the device into a specific biosensor. In this study, we demonstrate that functionalized AFM cantilevers could be used, in a process involving self-assembling layers, to create a homogeneous surface layer of the widely used herbicide mesotrione. Controlled experiments to evaluate its detection were performed, and binding between mesotrione and its target molecule, 4-hydroxyphenylpyruvate dioxygenase (HPPD), was evaluated using deflection curves of functionalized cantilevers interacting with mesotrione. The cantilevers worked as nanomechanical sensors inside a fluid cell device, under different concentrations of HPPD diluted in PBS. After eval...
ABSTRACT The herbicide residue from intensive agricultural activity provokes environmental distur... more ABSTRACT The herbicide residue from intensive agricultural activity provokes environmental disturbances and human health injuries. Among the enzymatic disruptor herbicides, mesotrione is able to inhibit 4-Hydroxyphenylpyruvate dioxygenase (HPPD), which plays a key role in the carotenoid synthesis. Therefore, enzyme-based sensors are innovative options for monitoring herbicides used in agriculture. Compared to the standard sensors, biosensors have assorted advantages, such as practicality, quick response, low cost, and high sensitivity. A nanobiosensor was developed herein based on HPPD for mesotrione detection. Theoretically, the Molecular Docking and Molecular Dynamics Simulation estimated the interacting regions of HPPD with mesotrione. Experimentally, the AFM tip functionalization with HPPD immobilized in self-assembled monolayers was confirmed by fluorescence microscopy and atomic force spectroscopy. The cross-linker EDC, which stands for N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, was responsible for properly preserve of the enzyme on the tip. The nanobiosensor proposed here was successfully able to detect mesotrione molecules. Such effectiveness in the development of nanobiosensors promises reliable, precise, low cost techniques, which apply to a broad range of issues, from ecology to medicine.
Cell adhesion, proliferation and differentiation are important specific parameters to be evaluate... more Cell adhesion, proliferation and differentiation are important specific parameters to be evaluated on biocompatibility studies of candidate biomaterials for clinical applications. Several different methodologies have been employed to study, both qualitative and quantitatively, the direct interactions of ceramic materials with cultured mammal and human cells. However, while quantitatively evaluating cell density, viability and metabolic responses to test materials, several methodological challenges may arise, either by impairing the use of some widely applied techniques, or by generating false or conflicting results. In this work, we tested the inherent interference of different representative calcium phosphate ceramic surfaces (stoichiometric dense and porous hydroxyapatite (HA) and cation-substituted apatite tablets) on different tests for quantitative evaluation of osteoblast adhesion and metabolism, either based on direct cell counting after trypsinization, colorimetric assays (X...
A hydrogel from cellulose acetate cross linked with ethylenediaminetetraacetic dianhydride (HAC-E... more A hydrogel from cellulose acetate cross linked with ethylenediaminetetraacetic dianhydride (HAC-EDTA) was synthesized by our research group, and submitted to characterization and biological tests. Cytocompatibility analysis was performed by confocal microscopy using human adipocyte derived stem cells (ASCs). The FTIR analysis showed characteristic bands of cellulose acetate and hydroxyl groups and the tensile tests evidence that HAC-EDTA present a Young's modulus of 643.7 MPa. The confocal analysis revealed that there was cell growth at the surface of HAC-EDTA. After one day of culture the cells presented spherical morphology, which may be caused by stress of the sequestration of Ca<sup>2+</sup> and Mg<sup>2+</sup> ions at the cell medium by HAC-EDTA, as demonstrated by ICP-MS. However, after seven days and 14 days of culture, the cells present fibroblastoid morphology, phenotype expected by this cellular type. The results give efforts to indicate this ne...
The state-of-the-art sustained drug delivery systems are related to features to improve pharmacol... more The state-of-the-art sustained drug delivery systems are related to features to improve pharmacological transport through a controlled ratio between drug release and the desired therapeutic effect. Microspheres of biodegradable polymers, such as poly(lactic-co-glycolic acid) (PLGA), play an important role in these approaches, directing the release in a specific region of interest. In this way, the encapsulation of doxycycline (DOX) as a microbial agent turns the PLGA microspheres into a potential device for the treatment of topic oral diseases. Thus, this work aimed to produce DOX-loaded PLGA microspheres and see how they interfered with mesenchymal stem cell viability and in the sustained release in antimicrobial assays. Scanning electron microscopy showed the spherical microstructured pattern, revealing assorted sized distribution, with major diameters ranging 1–3 µm. The encapsulation efficiency presented a mean of 80% in both methods to obtain the microspheres (sonication and ma...
A recent and quite promising technique for bone tissue engineering is the 3D printing, peculiarly... more A recent and quite promising technique for bone tissue engineering is the 3D printing, peculiarly regarding the production of high-quality scaffolds. The 3D printed scaffold strictly provides suitable characteristics for living cells, in order to induce treatment, reconstruction and substitution of injured tissue. The purpose of this work was to evaluate the behavior of the 3D scaffold based on Poly(L-co-D,L lactic acid-co-Trimethylene Carbonate) (PLDLA-TMC), which was designed in Solidworks™ software, projected in 3D Slicer™, 3D printed in filament extrusion, cultured with mesenchymal stem cells (MSCs) and tested in vitro and in vivo models. For in vitro study, the MSCs were seeded in a PLDLA-TMC 3D scaffold with 600 μm pore size and submitted to proliferation and osteogenic differentiation. The in vivo assays implanted the PLDLA-TMC scaffolds with or without MSCs in the calvaria of Wistar rats submitted to 8 mm cranial bone defect, in periods of 8–12 weeks. The results showed that...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2020
Introducao: Ao longo das decadas, com o melhor conhecimento da etiologia das doencas periodontais... more Introducao: Ao longo das decadas, com o melhor conhecimento da etiologia das doencas periodontais, foram desenvolvidas tecnicas de tratamento efetivo. O uso de agentes antimicrobianos, tanto sistemicos como locais, sao coadjuvantes essenciais ao tratamento mecânico. A doxiciclina (DOX), uma tetraciclina semi sintetica, e mais vantajosa que a tetraciclina por exibir maior absorcao bucal, tem meia-vida mais prolongada e mostra uma melhor solubilidade lipidica, o que e importante para a sua acao antibacteriana. Mesmo com o bom desempenho da doxiciclina, necessita-se de um veiculo que permita a liberacao e disposicao da mesma, no meio subgengival, por um periodo prolongado. Assim, o poli (L-Acido Latico-co-Acido Glicolico) (PLGA) representa um tipo de microparticulado polimerico que oferece uma abordagem alternativa para a liberacao de drogas, devido a sua biocompatibilidade, nao imunogenicidade, nao toxicidade, biodegradabilidade, metodos de preparacao simples e estabilidade fisicoquim...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2019
INTRODUCAO : O crescimento osseo, em decorrencia de fraturas, e acelerado atraves do uso de enxer... more INTRODUCAO : O crescimento osseo, em decorrencia de fraturas, e acelerado atraves do uso de enxertos osseos autogenos ou alogenicos. O primeiro e materialmente limitado e causa morbidade e irregularidades de contorno, e o segundo, esta refem de respostas imunes mediadas por celulas. Dessa forma, estudos com biomaterias, em especial os polimeros sinteticos, aptos para implantes osseos, sao alvos da engenharia de tecidos. Entre eles esta o biomaterial Poli(Lco-D,L acido latico-co-Trimetileno Carbonato), PLDLA-TMC, que apresenta algumas particularidades vantajosas para area medica, como o fato de ser um arcabouco poroso, com a possibilidade de induzir a diferenciacao osteogenica a partir de celulas mesenquimais. OBJETIVOS : Avaliar os efeitos do arcabouco PLDLA-TMC sobre a viabilidade da cultura de celulas mesenquimais e na diferenciacao osteoblastica. METODOS : O PLDLA-TMC foi sintetizado em forma de arcaboucos porosos 3D de 8mm de diâmetro, utilizados para a proliferacao e diferencia...
Revista da Faculdade de Ciências Médicas de Sorocaba, 2018
Introducao : Na atencao basica ao paciente queimado, o manejo dessas lesoes consiste atualmente n... more Introducao : Na atencao basica ao paciente queimado, o manejo dessas lesoes consiste atualmente na limpeza da ferida com agua, clorexidina degermante e administracao de agentes topicos bactericidas e profilaticos. Dessa forma, as praticas curativas utilizadas atualmente nao promovem, em grande parte, a regeneracao e cicatrizacao tecidual, funcionando apenas como barreiras fisicas e biologicas. Portanto, uma alternativa interessante ao atual tratamento de queimaduras e a utilizacao de biomateriais polimericos associados a moleculas indutoras, por serem biocompativeis, biodegradaveis, alem de minimizarem as reacoes adversas no organismo. Objetivos : Producao de um biomaterial que funcione como curativo para queimaduras de segundo grau, a base de POLI(ALCOOL VINILICO)/QUITOSANA/COLAGENO. Este material foi avaliado quanto a sua capacidade de induzir a regeneracao de queimaduras atraves de analises histologicas e morfometricas. Metodos : Para a realizacao do estudo, foram utilizados 40 r...
INTRODUCAO : A associacao de polimeros biocompativeis e biorreabsorviveis com celulas-tronco mese... more INTRODUCAO : A associacao de polimeros biocompativeis e biorreabsorviveis com celulas-tronco mesenquimais (CTMs) tem sido utilizada como alternativa de tratamento em lesoes e defeitos osseos, potencializando resultados e reduzindo custos. OBJETIVOS : Este projeto buscou analisar, por meio de tecnicas histologicas, o efeito da implantacao de um arcabouco de terpolimero poli (L-co-D,L acido latico-co-Trimetileno Carbonato) (PLDLA-TMC), cultivado com CTMs, na regeneracao de defeito osseo de tamanho critico confeccionado na calvaria de ratos Wistar, no intuito de potencializar a capacidade osteogenica e osteo reparadora do implante do biomaterial. METODOLOGIA : Foram utilizados 36 animais, divididos em 2 grupos conforme o tempo dos implantes (8 semanas e 12 semanas). Cada grupo, por sua vez, foi subdividido em 3 subgrupos iguais: controle negativo, defeito com PLDLA-TMC e defeito com PLDLA-TMC associado a CTMs. Por fim, os animais foram sacrificados e as amostras de suas calotas cranian...
O uso do poli(alcool-vinilico) (PVA) com nanoparticulas de prata (NpAg) como curativo cutâneo aum... more O uso do poli(alcool-vinilico) (PVA) com nanoparticulas de prata (NpAg) como curativo cutâneo aumentou. Na forma de membrana, o PVA atua como analogo epidermico, protegendo a lesao da desidratacao e mantendo-a umida. Ja o arcabouco de gelatina (gel) e acido hialuronico (AH) atua como derme substituta. As celulas-tronco mesenquimais derivadas de tecido adiposo humano (CTMs-TAh) podem ser cultivadas no arcabouco de gel-AH para produzirem substâncias que auxiliam na regeneracao dermica. Este estudo analisou a morfologia e citocompatibilidade do dispositivo PVA-NpAg/gelAH/CTM-TAh in vitro e investigou a ocorrencia de regeneracao dermica em lesao dorsal de espessura total em ratos Wistar. A morfologia do dispositivo foi analisada por microscopia eletronica. O ensaio de citocompatibildade foi realizado por microscopia confocal. Dividiu-se 60 ratos em 4 grupos: controle (somente lesao), PVA-NpAg, PVANpAg/gel-AH e PVA-NpAg/gel-AH/CTM-TAh. Eles foram sacrificados apos 14 e 28 dias e a pele d...
Introducao : A utilizacao de plantas e uma alternativa de baixo custo as drogas sinteticas utiliz... more Introducao : A utilizacao de plantas e uma alternativa de baixo custo as drogas sinteticas utilizadas no tratamento de queimaduras. Dentre as diversas plantas medicinais, a aroeira (Schinus terebinthifolius Raddi) demonstra ter propriedades anti-inflamatorias, antimicrobianas e antioxidantes que lhe atribuem um alto potencial cicatrizante [1]. Objetivos : Avaliar in vivo a acao cicatrizante da aroeira associada a membranas do terpolimero poli (L-co-D,L acido latico-co-TMC) (PLDLA-co-TMC) como matriz polimerica. Justificativas : Encontrar alternativas de baixo custo para o tratamento de queimaduras considerando que os curativos atuais para o tratamento desse tipo de lesao sao caros e nao estao disponiveis para uso no SUS. Metodologia : 30 ratos Wistar foram separados em grupos controle negativo e positivo, e grupo tratado. Apos anestesia foram submetidos a lesao termica por escaldo e apos 7 e 14 dias foram sacrificados e a pele lesionada foi retirada e processada para analise histolo...
Bioreactor systems that allow the simulation of in vivo variables in a controlled in vitro enviro... more Bioreactor systems that allow the simulation of in vivo variables in a controlled in vitro environment, were a great advance in the field of tissue engineering. Due to the dynamic-mechanical features that some tissues present, 3D-engineered constructs often do not exhibit the biomechanical properties of these native tissues. Thus, a successful approach must not only achieve tissue repair but also restore its function after injury. Here, we describe a method to improve cell activity in 3D scaffolds in a dynamic bioreactor system through the application of mechanical compression and fluid flow for tissue engineering approaches.
The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. Howev... more The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. However, the use of this hydrogel is challenging due to its favorable properties for microbiota growth. The association with silver nanoparticles (AgNPs) as an antimicrobial agent turns the match for PVA as a dressing, as it focuses on creating a physical barrier to avoid wound dehydration. When associated with extracellular components, such as the collagen matrix, the device obtained can create the desired biological conditions to act as a skin substitute. This study aimed to analyze the anti-microbiological activity and the in vitro and in vivo responses of a bilaminar device of PVA containing AgNPs associated with a membrane of collagen–hyaluronic acid (col-HA). Additionally, mesenchymal stem cells were cultured in the device to evaluate in vitro responses and in vivo immunomodulatory and healing behavior. The device morphology revealed a porous pattern that favored water retention and in ...
Nanomechanical biosensors based on atomic force microscopy (AFM) cantilevers have garnered consid... more Nanomechanical biosensors based on atomic force microscopy (AFM) cantilevers have garnered considerable attention. AFM cantilevers are devices that can detect a target either via a surface functionalization process based on immobilization through molecular adsorption, or through the selective chemical binding of a specific molecule, transforming the device into a specific biosensor. In this study, we demonstrate that functionalized AFM cantilevers could be used, in a process involving self-assembling layers, to create a homogeneous surface layer of the widely used herbicide mesotrione. Controlled experiments to evaluate its detection were performed, and binding between mesotrione and its target molecule, 4-hydroxyphenylpyruvate dioxygenase (HPPD), was evaluated using deflection curves of functionalized cantilevers interacting with mesotrione. The cantilevers worked as nanomechanical sensors inside a fluid cell device, under different concentrations of HPPD diluted in PBS. After eval...
ABSTRACT The herbicide residue from intensive agricultural activity provokes environmental distur... more ABSTRACT The herbicide residue from intensive agricultural activity provokes environmental disturbances and human health injuries. Among the enzymatic disruptor herbicides, mesotrione is able to inhibit 4-Hydroxyphenylpyruvate dioxygenase (HPPD), which plays a key role in the carotenoid synthesis. Therefore, enzyme-based sensors are innovative options for monitoring herbicides used in agriculture. Compared to the standard sensors, biosensors have assorted advantages, such as practicality, quick response, low cost, and high sensitivity. A nanobiosensor was developed herein based on HPPD for mesotrione detection. Theoretically, the Molecular Docking and Molecular Dynamics Simulation estimated the interacting regions of HPPD with mesotrione. Experimentally, the AFM tip functionalization with HPPD immobilized in self-assembled monolayers was confirmed by fluorescence microscopy and atomic force spectroscopy. The cross-linker EDC, which stands for N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, was responsible for properly preserve of the enzyme on the tip. The nanobiosensor proposed here was successfully able to detect mesotrione molecules. Such effectiveness in the development of nanobiosensors promises reliable, precise, low cost techniques, which apply to a broad range of issues, from ecology to medicine.
Cell adhesion, proliferation and differentiation are important specific parameters to be evaluate... more Cell adhesion, proliferation and differentiation are important specific parameters to be evaluated on biocompatibility studies of candidate biomaterials for clinical applications. Several different methodologies have been employed to study, both qualitative and quantitatively, the direct interactions of ceramic materials with cultured mammal and human cells. However, while quantitatively evaluating cell density, viability and metabolic responses to test materials, several methodological challenges may arise, either by impairing the use of some widely applied techniques, or by generating false or conflicting results. In this work, we tested the inherent interference of different representative calcium phosphate ceramic surfaces (stoichiometric dense and porous hydroxyapatite (HA) and cation-substituted apatite tablets) on different tests for quantitative evaluation of osteoblast adhesion and metabolism, either based on direct cell counting after trypsinization, colorimetric assays (X...
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