Estudio de biocompatibilidad de matrices poliméricas combinadas, responsivas al pH, con aplicación en Ingeniería de Tejido Óseo / Biocompatibility study of combined pH-responsive polymeric matrices with application in Bone Tissue Engineering

El presente trabajo muestra la obtención de un material a partir de un polímero sintético (TerP) y otro natural, mediante entrecruzamiento físico y su caracterización fisicoquímica y biológica, con el fin de emplearlos para regeneración de tejido óseo. Las membranas fueron obtenidas por la técnica de evaporación del solvente y caracterizadas por espectroscopia FTIR, ensayos de hinchamiento, medidas de ángulo de contacto y microscopia electrónica de barrido (SEM). Se encontró que la compatibilidad entre los polímeros que la constituyen es estable a pH fisiológico y que, al incorporar mayor cantidad del TerP a la matriz, esta se vuelve más hidrofóbica y porosa. Además, teniendo en cuenta la aplicación prevista para dichos materiales, se realizaron estudios de biocompatibilidad y citotoxicidad con células progenitoras de médula ósea (CPMO) y células RAW264.7, respectivamente. Se evaluó la proliferación celular, la producción y liberación de óxido nítrico (NO) al medio de cultivo durante 24 y 48 horas y la expresión de citoquinas proinflamatorias IL-1ß y TNF-α de las células crecidas sobre los biomateriales variando la cantidad del polímero sintético. Se encontró mayor proliferación celular y menor producción de NO sobre las matrices que contienen menos proporción del TerP, además de poseer una mejor biocompatibilidad. Los resultados de este estudio muestran que el terpolímero obtenido y su combinación con un polímero natural es una estrategia muy interesante para obtener un biomaterial con posibles aplicaciones en medicina regenerativa y que podría extenderse a otros sistemas estructuralmente relacionados. (AU)

In the present work, the preparation of a biomaterial from a synthetic terpolymer (TerP) and a natural polymer, physically crosslinked, is shown. In order to evaluate the new material for bone tissue regeneration, physicochemical and biological characterizations were performed. The membranes were obtained by solvent casting and characterized using FTIR spectroscopy, swelling tests, contact angle measurements, and scanning electron microscopy (SEM). It was found that the compatibility between the polymers is stable at physiological pH and the incorporation of a higher amount of TerP into the matrix increases hydrophobicity and porosity.Furthermore, considering the intended application of these materials, studies of biocompatibility and cytotoxicity were conducted with Bone Marrow Progenitor Cells (BMPCs) and RAW264.7 cells, respectively. Cell proliferation, NO production and release into the culture medium for 24 and 48 hours, and proinflammatory cytokine expression of IL-1ß and TNF-α from cells grown on the biomaterials while varying the amount of the synthetic polymer were evaluated. Greater cell proliferation and lower NO production were found on matrices containing a lower proportion of TerP, in addition to better biocompatibility. The results of this study demonstrate that the obtained terpolymer and its combination with a natural polymer is a highly interesting strategy for biomaterial preparation with potential applications in regenerative medicine. This approach could be extended to other structurally related systems. (AU)

Evaluation of contact angle and mechanical properties of resin monomers filled with graphene oxide nanofibers

Abstract This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior.

Resumo Este estudo in vitro sintetizou nanofibras híbridas embebidas em óxido de grafeno (GO), incorporando-as à uma resina composta experimental de monômeros para avaliar suas propriedades físico-mecânicas. Nanofibras híbridas inorgânica-orgânicas foram produzidas com soluções precursoras de fibras poli (d, l-lactídeo, PLA) preenchidas com GO a 1% em peso e microscopia eletrônica de varredura (MEV) e espectroscopia de raio-X de energia dispersiva (EDS) caracterizaram a morfologia e composição química das fibras. Monômeros de resina composta foram desenvolvidos e um total de 5% de nanofibras foi incorporado aos materiais experimentais. Três grupos foram desenvolvidos: G1 (monômeros de resina controle), G2 (monômeros de resina/ nanofibras de PLA) e G3 (monômeros de resina/nanofibras híbridas inorgânico-orgânicas). Ângulo de contato (n=3), resistência à flexão (n=22), módulo de elasticidade (n=22) e dureza Knoop (n=6) foram avaliados. A média das três endentações foi obtida para cada amostra. A normalidade dos dados foi avaliada pelo QQ Plot com envelopes simulados e analisada pelo método de Welch (p<0,05). No geral, as imagens de MEV mostraram forma regular de nanofibras, mas não alinhadas. A análise composicional de EDS (n=6) revelou a presença de carbono e oxigênio (presentes na composição do GO) e Si resultante do processo de funcionalização. Os resultados do ângulo de contato (°) e dureza (Kg/mm2) para cada grupo foram os seguintes, respectivamente: G1 (59,65±2,90; 37,48±1,86a), G2 (67,99±3,93; 50,56±1,03b) e G3 (62,52±7,40; 67,83±1,01c). G3 apresentou os maiores valores de dureza Knoop (67,83 kg/mm2), e a resistência à flexão de todos os grupos foi prejudicada. A resina composta experimental composta por nanofibras híbridas com GO apresentou maiores valores de dureza e comportamento hidrofílico.

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT-Raman spectroscopy / Cultivo de células-tronco mesenquimais de rato sobre arcabouços de PHBV-PCL: análise do meio de cultura condicionado por espectroscopia de FT-Raman

Abstract Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37oC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

Resumo As células-tronco mesenquimais (MSCs) possuem grande potencial para aplicação em procedimentos terapêuticos ligados a terapia celular e engenharia de tecidos, considerando-se a plasticidade e capacidade de formação em diferentes tipos celulares por elas. Dada a abrangência no emprego das MSCs, há necessidade de se compreender melhor algumas propriedades relacionadas à diferenciação osteogênica, particularmente liga à biomateriais usados em engenharia de tecidos. Este projeto objetiva o desenvolvimento de uma metodologia de análise empregando-se a FT-Raman para identificação e quantificação de componentes bioquímicos presentes em meios de cultura condicionados por MSCs, com ou sem indução à diferenciação osteogênica. Todos os experimentos foram realizados entre as passagens 3 e 5. Para essas análises, as MSCs foram cultivadas sobre arcabouços de polímeros biorreabsorvíveis de poli (hidroxibutirato-co-hidroxivalerato) (PHBV) e o poli (ε-caprolactona) (PCL). As MSCs (GIBCO®) foram inoculadas nos polímeros puros e na mistura 75:25 de PHBV / PCL (amostras densas e porosas). As células foram mantidas em DMEM (com baixa glicose) contendo GlutaMAX® e 10% de SFB a 37oC com 5% de CO2 por 21 dias. A própria placa foi usada como controle. Os meios de cultura condicionados foram coletados e analisadas em FT-Raman para sondagem de grupos funcionais, bem como possíveis variações moleculares associadas com a diferenciação e metabolismo celular. Foi possível discernir grupos funcionais de moléculas específicas no meio condicionado, como colesterol, fosfatidilinositol, triglicerídeos, forma Beta de polipeptídeos, regiões de amida e ligações de hidrogênio de proteínas, além da expressão de DNA. Na presente avaliação, a FT-Raman apresentou como uma técnica de resolução limitada, uma vez que modos vibracionais de estiramento próximos ou mesmo iguais podem ser expressos por moléculas diferente, dificultando a análise. Não houve variações nas leituras entre as amostras estudadas, concluindo-se que a FT-Raman não atendeu às expectativas nas condições estudadas.

Advances in Mechanotransduction Pathway of Macrophage / 医用生物力学

Mechanical stimulation in micro-environment ( such as matrix stiffness, surface topography, cyclical stretch) can be perceived by macrophages through receptors on cell membrane, transmitted to the nucleus along the adhesion protein molecular chain and cytoskeleton, and also converted into biochemical signal to stimulate gene transcription. Mechanical stimulation drives various biological functions in macrophages, such as adhesion, proliferation, migration, and polarization, thereby playing a corresponding role in disease progression and tissue regeneration. This study demonstrates the role of micro-environment mechanics in macrophages polarization and function, and elucidates the related mechanism of mechanotransduction pathway in macrophages, so as to provide molecular biomechanics insights into the development of macrophage-targeting immunomodulatorybiomaterials.

Progress in preparation and application of biomimetic nano carriers for cell membrane / 药学实践杂志

Nanocarriers prepared from organic or inorganic materials are widely used in drug targeting system and diagnosis and treatment of disease. However, there are some problems, such as poor targeting, short circulation time in vivo and improvement in the biocompatibility. Biomimetic nanocarriers has carried out research on the issues, which based on different kinds of cell membrane for the nanocarriers modification, endogenous biofilm improving the biocompatibility of carriers in vivo, more accurate targeting, and even producing immunotherapeutic effect. The principle, method, targeting mechanism and therapeutic effect of biomimetic nano carrier technology of cell membrane have been reviewed in this paper, which provide a new direction for the research of new drug delivery system.

The degradation of plastics and the production of polyhydroxyalkanoates (PHA) / 生物工程学报

In recent years, the petroleum-based plastic pollution problem has been causing global attention. The idea of "degradation and up-cycling of plastics" was proposed for solving the environmental pollution caused by non-degradable plastics. Following this idea, plastics would be firstly degraded and then reconstructed. Polyhydroxyalkanoates (PHA) can be produced from the degraded plastic monomers as a choice to recycle among various plastics. PHA, a family of biopolyesters synthesized by many microbes, have attracted great interest in industrial, agricultural and medical sectors due to its biodegradability, biocompatibility, thermoplasticity and carbon neutrality. Moreover, the regulations on PHA monomer compositions, processing technology, and modification methods may further improve the material properties, making PHA a promising alternative to traditional plastics. Furthermore, the application of the "next-generation industrial biotechnology (NGIB)" utilizing extremophiles for PHA production is expected to enhance the PHA market competitiveness, promoting this environmentally friendly bio-based material to partially replace petroleum-based products, and achieve sustainable development with carbon-neutrality. This review summarizes the basic material properties, plastic upcycling via PHA biosynthesis, processing and modification methods of PHA, and biosynthesis of novel PHA.

Wearable patches for transdermal drug delivery

Transdermal drug delivery systems (TDDs) avoid gastrointestinal degradation and hepatic first-pass metabolism, providing good drug bioavailability and patient compliance. One emerging type of TDDs is the wearable patch worn on the skin surface to deliver medication through the skin. They can generally be grouped into passive and active types, depending on the properties of materials, design principles and integrated devices. This review describes the latest advancement in the development of wearable patches, focusing on the integration of stimulus-responsive materials and electronics. This development is deemed to provide a dosage, temporal, and spatial control of therapeutics delivery.

Research progress in leveraging biomaterials for enhancing NK cell immunotherapy / 浙江大学学报·医学版

NK cell immunotherapy is a promising antitumor therapeutic modality after the development of T cell immunotherapy. Structural modification of NK cells with biomaterials may provide a precise, efficient, and low-cost strategy to enhance NK cell immunotherapy. The biomaterial modification of NK cells can be divided into two strategies: surface engineering with biomaterials and intracellular modification. The surface engineering strategies include hydrophobic interaction of lipids, receptor-ligand interaction between membrane proteins, covalent binding to amino acid residues, click reaction and electrostatic interaction. The intracellular modification strategies are based on manipulation by nanotechnology using membranous materials from various sources of NK cells (such as exosome, vesicle and cytomembranes). Finally, the biomaterials-based strategies regulate the recruitment, recognition and cytotoxicity of NK cells in the solid tumor site in situ to boost the activity of NK cells in the tumor. This article reviews the recent research progress in enhancing NK cell therapy based on biomaterial modification, to provide a reference for further researches on engineering NK cell therapy with biomaterials.

Progress in the application of patch materials in cardiovascular surgery / 中南大学学报(医学版)

The cardiovascular patch, served as artificial graft materials to replace heart or vascular tissue defect, is still playing a key role in cardiovascular surgeries. The defects of traditional cardiovascular patch materials may determine its unsatisfactory long-term effect or fatal complications after surgery. Recent studies on many new materials (such as tissue engineered materials, three-dimensional printed materials, etc) are being developed. Patch materials have been widely used in clinical procedures of cardiovascular surgeries such as angioplasty, cardiac atrioventricular wall or atrioventricular septum repair, and valve replacement. The clinical demand for better cardiovascular patch materials is still urgent. However, the cardiovascular patch materials need to adapt to normal coagulation mechanism and durability, promote short-term endothelialization after surgery, and inhibit long-term postoperative intimal hyperplasia, its research and development process is relatively complicated. Understanding the characteristics of various cardiovascular patch materials and their application in cardiovascular surgeries is important for the selection of new clinical surgical materials and the development of cardiovascular patch materials.

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT Raman spectroscopy / Cultivo de células-tronco mesenquimais de rato sobre arcabouços de PHBV-PCL: análise do meio de cultura condicionado por espectroscopia de FT-Raman

Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37ºC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

As células-tronco mesenquimais (MSCs) possuem grande potencial para aplicação em procedimentos terapêuticos ligados a terapia celular e engenharia de tecidos, considerando-se a plasticidade e capacidade de formação em diferentes tipos celulares por elas. Dada a abrangência no emprego das MSCs, há necessidade de se compreender melhor algumas propriedades relacionadas à diferenciação osteogênica, particularmente liga à biomateriais usados em engenharia de tecidos. Este projeto objetiva o desenvolvimento de uma metodologia de análise empregando-se a FT-Raman para identificação e quantificação de componentes bioquímicos presentes em meios de cultura condicionados por MSCs, com ou sem indução à diferenciação osteogênica. Todos os experimentos foram realizados entre as passagens 3 e 5. Para essas análises, as MSCs foram cultivadas sobre arcabouços de polímeros biorreabsorvíveis de poli (hidroxibutirato-co-hidroxivalerato) (PHBV) e o poli (ε-caprolactona) (PCL). As MSCs (GIBCO®) foram inoculadas nos polímeros puros e na mistura 75:25 de PHBV / PCL (amostras densas e porosas). As células foram mantidas em DMEM (com baixa glicose) contendo GlutaMAX® e 10% de SFB a 37oC com 5% de CO2 por 21 dias. A própria placa foi usada como controle. Os meios de cultura condicionados foram coletados e analisadas em FT-Raman para sondagem de grupos funcionais, bem como possíveis variações moleculares associadas com a diferenciação e metabolismo celular. Foi possível discernir grupos funcionais de moléculas específicas no meio condicionado, como colesterol, fosfatidilinositol, triglicerídeos, forma Beta de polipeptídeos, regiões de amida e ligações de hidrogênio de proteínas, além da expressão de DNA. Na presente avaliação, a FT-Raman apresentou como uma técnica de resolução limitada, uma vez que modos vibracionais de estiramento próximos ou mesmo iguais podem ser expressos por moléculas diferente, dificultando a [...].

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT-Raman spectroscopy

Abstract Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37oC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

Resumo As células-tronco mesenquimais (MSCs) possuem grande potencial para aplicação em procedimentos terapêuticos ligados a terapia celular e engenharia de tecidos, considerando-se a plasticidade e capacidade de formação em diferentes tipos celulares por elas. Dada a abrangência no emprego das MSCs, há necessidade de se compreender melhor algumas propriedades relacionadas à diferenciação osteogênica, particularmente liga à biomateriais usados em engenharia de tecidos. Este projeto objetiva o desenvolvimento de uma metodologia de análise empregando-se a FT-Raman para identificação e quantificação de componentes bioquímicos presentes em meios de cultura condicionados por MSCs, com ou sem indução à diferenciação osteogênica. Todos os experimentos foram realizados entre as passagens 3 e 5. Para essas análises, as MSCs foram cultivadas sobre arcabouços de polímeros biorreabsorvíveis de poli (hidroxibutirato-co-hidroxivalerato) (PHBV) e o poli (-caprolactona) (PCL). As MSCs (GIBCO®) foram inoculadas nos polímeros puros e na mistura 75:25 de PHBV / PCL (amostras densas e porosas). As células foram mantidas em DMEM (com baixa glicose) contendo GlutaMAX® e 10% de SFB a 37oC com 5% de CO2 por 21 dias. A própria placa foi usada como controle. Os meios de cultura condicionados foram coletados e analisadas em FT-Raman para sondagem de grupos funcionais, bem como possíveis variações moleculares associadas com a diferenciação e metabolismo celular. Foi possível discernir grupos funcionais de moléculas específicas no meio condicionado, como colesterol, fosfatidilinositol, triglicerídeos, forma Beta de polipeptídeos, regiões de amida e ligações de hidrogênio de proteínas, além da expressão de DNA. Na presente avaliação, a FT-Raman apresentou como uma técnica de resolução limitada, uma vez que modos vibracionais de estiramento próximos ou mesmo iguais podem ser expressos por moléculas diferente, dificultando a análise. Não houve variações nas leituras entre as amostras estudadas, concluindo-se que a FT-Raman não atendeu às expectativas nas condições estudadas.

Efeito biológico do laser de baixa intensidade em osteoblastos cultivados na superfície de arcabouços poliméricos tridimensionais / Biological effect of low-intensity laser on osteoblasts cultured on the surface of three-dimensional polymeric scaffolds

A primeira parte do trabalho avaliou, através de uma revisão sistemática de estudos in vitro, a aplicabilidade da fotobiomodulação como uma ferramenta auxiliar na engenharia de tecidos. De 8373 estudos inicialmente identificados a partir das estratégias de busca, dez artigos atingiram os critérios de inclusão para análise. Os dados obtidos na maioria dos estudos revisados indicaram que a laserterapia de baixa intensidade (LBI) pode aumentar a proliferação e diferenciação de células cultivadas na superfície dos biomateriais. Na segunda parte do trabalho foi avaliado o efeito da LBI na dose de 4 J/cm2 na proliferação de osteoblastos (OFCOL II) cultivados na superfície de arcabouços poliméricos tridimensionais (3D) de ácido polilático (PLA) e de PLA associado a quitosana (PLA/Q) produzidos pela técnica de fiação por sopro em solução. O ensaio do Alamar Blue demonstrou que as células OFCOL II cultivadas sobre os arcabouços 3D de PLA e irradiadas apresentaram uma maior atividade proliferativa quando comparadas aos grupos não irradiados no intervalo de 72 h. Além disso, as células OFCOL II cultivadas sobre arcabouços de PLA/Q também apresentaram uma maior atividade proliferativa em 24 h. A análise pela microscopia eletrônica de varredura (MEV) mostrou que os osteoblastos se encontravam ancorados em concavidades das fibras nos arcabouços examinados. Concluiu-se que o modelo proposto apresentou um potencial para estudos na área da engenharia tecidual óssea. Na terceira parte do trabalho foi avaliada a influência da LBI infravermelha (IV) e vermelha (V) em diferentes dosagens (1 J/cm², 4 J/cm² e 6 J/cm²) na proliferação e viabilidade das células OFCOL II. O ensaio do Alamar Blue mostrou diferenças significativas (p<0,05) na atividade mitocondrial do grupo IV utilizando a dose de 1 J/cm2 e 4 J/cm2, nos intervalos de 24 e 48 h. Já o ensaio do Live/Dead evidenciou que a LBI induziu aumento da viabilidade celular no grupo IV na dose de 4 J/cm2, quando comparada com os demais grupos. Em conjunto, os resultados sugerem que a LBI pode promover bioestimulação in vitro de osteoblastos, inclusive quando cultivados na superfície de arcabouços poliméricos 3D, representando assim uma ferramenta promissora nas técnicas de engenharia tecidual óssea (AU).

The first part of the work evaluated, through a systematic review of in vitro studies, the applicability of photobiomodulation as an auxiliary tool in tissue engineering. Of 8373 studies initially identified from the search strategies, ten articles met the inclusion criteria for analysis. Data obtained from most of the reviewed studies indicated that low-intensity laser therapy (LLLT) could increase the proliferation and differentiation of cells cultured on the surface of biomaterials. The second part of the work evaluated the effect of LLLT at a dose of 4 J/cm² on the proliferation of osteoblasts (OFCOL II) cultivated on the surface of threedimensional (3D) polymer scaffolds of polylactic acid (PLA) and PLA associated with chitosan (PLA/Q) produced by the solution blow spinning technique. The Alamar Blue assay demonstrated that OFCOL II cells cultured on 3D PLA scaffolds and irradiated showed more significant proliferative activity when compared to non-irradiated groups within 72 h. Furthermore, OFCOL II cells cultured on PLA/Q scaffolds showed higher proliferative activity at 24 h. Analysis by scanning electron microscopy (SEM) showed that the osteoblasts were anchored in the concavities of the fibers of the examined scaffolds. It was concluded that the proposed model showed potential for studies in the field of bone tissue engineering. The third part of the work evaluated the influence of infrared (IR) and red (R) laser therapy at different dosages (1 J/cm², 4 J/cm², and 6 J/cm²) on the proliferation and viability of OFCOL II cells. The Alamar Blue assay showed significant differences (p<0.05) in the mitochondrial activity of group IR using the dose of 1 J/cm² and 4 J/cm² at 24 and 48 h. The Live/Dead assay showed that LLLT induced an increase in cell viability in the IR group at a dose of 4 J/cm² compared to the other groups. Taken together, the results suggest that LLLT can promote in vitro biostimulation of osteoblasts, even when cultivated on the surface of 3D polymeric scaffolds, thus representing a promising tool in bone tissue engineering techniques (AU).

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

Análise comparativa entre técnicas cirúrgicas de enxertia óssea em reabilitação de maxila atrófica: transplante celular odontológico (TCO) e técnica convencional de enxertia óssea ­ relato de caso clínico / Comparative analysis between surgical techniques of bone grafting in rehabilitation of atrophic maxilla: dental cell transplantation (OCT) and conventional bone grafting technique - a case report

A reabilitação de maxila atrófica se apresenta ainda nos dias de hoje como um desafio anatômico/fisiológico para os profissionais da área odontológica que visam buscar a instalação de implantes para futuras reabilitações protéticas, tendo em vista o grau de dificuldade de reconstituição do rebordo alveolar perdido. Com o intuito de reabilitar essas maxilas frente às adversidades, diferentes técnicas são propostas tais como enxertos ósseos autógenos, homógenos, substitutos ósseos alógenos, xenógenos e aloplásticos e suas respectivas técnicas. O objetivo deste trabalho foi apresentar um relato de caso clínico, no qual duas técnicas de reconstituição de rebordo alveolar de hemi-arco foram realizadas na mesma maxila utilizando biomaterial em bloco, visando comparar os resultados histológicos e clínicos. Após 5 meses da realização da enxertia, foi coletado material dos enxertos alveolares bilateralmente utilizando-se brocas trefinas para estudo histológico. Através da metodologia empregada, pode-se observar maior formação de estrutura óssea no lado em que foi praticada a metodologia transplantes celular odontológico (TCO), que preconiza a associação de sangue medular mandibular ao biomaterial, em relação a técnica contralateral em que utilizou a metodologia convencional, que preconiza a associação ao biomaterial do sangue periférico. Pode-se observar através da metodologia empregada que a utilização de biomateriais potencializados com sangue medular mandibular apresentou maior crescimento de estrutura óssea, incrementando em torno de 35% a mais na neoformação.de osso vital.

The rehabilitation of atrophic maxilla is still presented today as an anatomical/physiological challenge for professionals in the dental field who aim to seek the installation of implants for future prosthetic rehabilitations, in view of the degree of difficulty in reconstituting the lost alveolar ridge. In order to rehabilitate these jaws in the face of adversity, different techniques are proposed such as autogenous, homogenous bone grafts, allogeneic, xenogenous and alloplastic bone substitutes and their respective techniques. The aim of this study was to present a clinical case report, in which two hemi-arch alveolar ridge reconstruction techniques were performed in the same maxilla using biomaterial en bloc, in order to compare the histological and clinical results. After 5 months of grafting, material was collected from the alveolar grafts bilaterally using trephine burs for histological study. Through the used methodology, it was possible to see greater bone formation of structure on the side in which the dental cell transplantation (TCO) methodology was practiced, which advocates the association of mandibular medullary blood to the biomaterial, in relation to the contralateral technique in which the methodology was used conventional method, which advocates the association with peripheral blood biomaterial. It can be observed through the used methodology that the use of biomaterials potentiated with mandibular medullary blood showed greater growth of bone structure, increasing around 35% more in the neoformation of vital bone.

A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process.(AU)

Progress in Biomechanics of Materials in 2021 / 医用生物力学

Tissue has a complex three-dimensional (3D) dynamic structure, and is affected by various forms of forces. Cells sense mechanical forces from extracellular matrix (ECM), and the mechanical micro-environment constructed by ECM regulates different biological functions of cells. To prepare biomaterials which can simulate the ECM mechanical micro-environment of tissues is one of the research hot spots and difficulties in biomechanical field. Different physical and chemical properties of biomaterials endow materials with specific mechanical properties, which further affect the behavior and function of cells. Based on the latest literature of biomechanics of materials in the year 2021, this study mainly focused on the role of novel mechanical biomaterials in regulating cell biological behavior and application in tissue engineering. The future development direction in the field of biomechanics of materials was also discussed.

Research progress on detection methods of pyrethroid insecticide residues in human biomaterials / 环境与职业医学

In recent years, due to the wide use of pyrethroid insecticides, the impact of pyrethroid insecticides on human health cannot be ignored. Therefore, how to detect pyrethroid insecticide residues in human body accurately and efficiently has become a research hotspot. However, it is difficult to detect pyrethroid insecticides because of its low residues and fast metabolism. Our article reviewed research on the detection of pyrethroid pesticide residues in human biomaterials in recent years, listed various pretreatment methods and detection methods of different biomaterials in detail, as well as summarized reported limits of detection, limits of quantitation, and recoveries of different methods. Finally, we prospected further development in detection methods of pyrethroid pesticide residues in human biomaterials.

A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

Abstract Background: The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process.

Research advances of three-dimensional bioprinting technology in urinary system tissue engineering / 生物医学工程学杂志

For the damage and loss of tissues and organs caused by urinary system diseases, the current clinical treatment methods have limitations. Tissue engineering provides a therapeutic method that can replace or regenerate damaged tissues and organs through the research of cells, biological scaffolds and biologically related molecules. As an emerging manufacturing technology, three-dimensional (3D) bioprinting technology can accurately control the biological materials carrying cells, which further promotes the development of tissue engineering. This article reviews the research progress and application of 3D bioprinting technology in tissue engineering of kidney, ureter, bladder, and urethra. Finally, the main current challenges and future prospects are discussed.

Research progress on action mechanism and clinical application of hyaluronic acid / 药学实践杂志

Hyaluronic acid is widely present in the human body. It is an important component of extracellular matrix. It has unique hydrodynamic properties, good viscoelasticity and strain properties. At present, hyaluronic acid has been widely used in biomaterials, targeted-drug preparations, cosmetics and prevention of adhesion after abdominal surgery. With the expansion of the application scope of hyaluronic acid and the continuous emergence of new medical materials, the research on hyaluronic acid has been increasing in recent years. This paper reviews the clinical application of hyaluronic acid and its mechanism, in order to provide reference for the further development and safe application of hyaluronic acid products.