RESUMO
Hydrogels from natural sources are attracting increasing interest due to their ability to protect biologically active molecules. Starch extracted from cassava tubers is a promising material for synthesizing these hydrogels. Copolymerization of cassava gum and incorporation of chlorhexidine digluconate (CLX) into the hydrogels is confirmed by changes in the crystallographic profile, as observed through X-ray diffraction, and a shift in the 1000 cm-1 band in the Fourier-transform infrared spectroscopy spectrum. The differential scanning calorimetry reveals changes in the decomposition temperature of the synthesized hydrogels related to CLX volatility. Micrographs illustrate the material's porosity. Release tests indicate a constant linear release over 72 h, while antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans is satisfactory, with 100% effectiveness from 0.5% CLX and the formation of inhibition halos. Toxicity and biocompatibility studies show no cytotoxicity. The continuous release of chlorhexidine is promising for components of biomedical implants and applications as it can ensure antimicrobial action according to specific therapeutic needs.
Assuntos
Anti-Infecciosos , Candida albicans , Clorexidina , Escherichia coli , Hidrogéis , Manihot , Staphylococcus aureus , Clorexidina/farmacologia , Clorexidina/química , Clorexidina/análogos & derivados , Manihot/química , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/síntese química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/síntese química , Gomas Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Testes de Sensibilidade Microbiana , Liberação Controlada de FármacosRESUMO
Cashew tree gum is a polysaccharide material highly available in the Northeast region of Brazil. It has been explored for biocompatibility with human tissues. This research aimed to describe the synthesis and characterization of cashew gum/hydroxyapatite scaffold and evaluate the possible cytotoxicity in murine adipose-derived stem cells (ADSCs) cultures. ADSCs of the subcutaneous fat tissue of Wistar rats were collected, isolated, expanded, differentiated into three strains, and characterized immunophenotypically. The scaffolds were synthesized through chemical precipitation, lyophilized and characterized through scanning electron microscopy (SEM), infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal analysis (TG and DTG), and mechanical testing. The scaffold presented a crystalline structure and pores with an average diameter of 94.45 ± 50.57 µm. By mechanical tests, the compressive force and modulus of elasticity were like the cancellous bone. The isolated adipose-derived stem cells (ADSCs) presented fibroblast morphology, adhesion capacity to plastic, differentiation in osteogenic, adipogenic and chondrogenic lineages, positive expression for the CD105 and CD90 markers and negative expression for the CD45 and CD14 markers. The MTT test showed increased cell viability, and the biomaterial showed a high level of hemocompatibility (<5 %). This study allowed the development of a new scaffold for future surgical applicability in tissue regeneration.
Assuntos
Anacardium , Materiais Biocompatíveis , Ratos , Camundongos , Humanos , Animais , Materiais Biocompatíveis/farmacologia , Alicerces Teciduais/química , Árvores , Durapatita , Ratos Wistar , Diferenciação Celular , Osteogênese , Técnicas de Cultura de Células , Engenharia Tecidual/métodosRESUMO
The development of 'smart' scaffolds has achieved notoriety among current prospects for bone repair, especially for chronic osteopathy, such as osteoporosis. Millions of individuals in the world suffer from poor bone healing due to osteoporosis. The objective of this work was to produce and characterize castor polyurethane (PU) scaffolds (Ricinus communisL.)andevaluate itsin vitrobiocompatibility with stem cells and osteoinductive effectin vivoon bone failures in a leporid model of osteoporosis. The material was characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, SEM, and porosity analysis. Then, the biocompatibility was assessed by adhesion using SEM and cytotoxicity in a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium assay. The osteoinductive effectin vivowas determined in bone defects in rabbit tibias (Oryctolagus cuniculus) submitted to castor PU scaffold, castor PU scaffold associated with stem cells, and negative control, after four and eight weeks, evaluated by computed microtomography and histopathology. The scaffolds were porous, with an average pore size of 209.5 ± 98.2 µm, absence of cytotoxicity, and positive cell adhesivenessin vitro.All the animals presented osteoporosis, characterized by multifocal osteoblastic inactivity and areas of mild fibrosis. There were no statistical differences between these treatments in the fourth week of treatment. In the eighth week, the treatment with castor PU scaffold alone induced more significant bone formation when compared to the other groups, followed by treatment with an association between castor PU scaffold and stem cells. The castor PU scaffold was harmless to cell culture, favoring cell adhesiveness and proliferation, in addition to inducing bone neoformation in osteoporotic rabbits.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Osteoporose/metabolismo , Poliuretanos , Ricinus/química , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Osso e Ossos/lesões , Osso e Ossos/metabolismo , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Poliuretanos/química , Poliuretanos/farmacologia , Coelhos , Microtomografia por Raio-XRESUMO
Cell replacement through neural stem cells has been a promising alternative therapy for neurodegenerative diseases. It was evaluated the possible protect and/or prevent role of neurospheres in experimental models of epilepsy by the use of biomarkers of oxidative stress and histopathological analysis. After 1 h of the epileptic inductions by pilocarpine, pentylenotetrazole and picrotoxin, rats were infused with a suspension of 2 × 106 cells/0.25 mL, marked with Qtracker® 655, via caudal vein. In the control group epilepsy was not induced, but received the cell infusion under the same conditions of other groups. After 30 days, the rats were euthanized, and the removal of the brain was proceeded to later perform the assays oxidative stress and histopathology analysis. Thiobarbituric acid and nitrite levels were elevated in epileptic groups treated with neurospheres, and the levels of reduced glutathione, superoxide dismutase and catalase were reduced when compared to non-treated groups. The performance of oxidative enzymes from pilocarpine group treated with neurospheres showed slight increase. Histopathological evaluation observed distribution of neurospheres throughout the brain tissue, with viable cells and in process of differentiation in the pilocarpine group, but with differentiation and regeneration compromised in epilepsy by picrotoxin and pentylenetetrazole due to a microenvironment of oxidative stress. Neural stem cell therapy has a promising potential for protection in the pilocarpine epilepsy model, suggesting that the antioxidant system of neurospheres could reduce oxidative damage generated by seizure.
Assuntos
Células-Tronco Neurais/transplante , Estresse Oxidativo/fisiologia , Convulsões/fisiopatologia , Transplante de Células-Tronco/métodos , Animais , Encéfalo/fisiopatologia , Convulsivantes/toxicidade , Feminino , Masculino , Pilocarpina/toxicidade , Ratos , Ratos Wistar , Convulsões/induzido quimicamenteRESUMO
Mesenchymal stem cells (MSCs), obtained from several anatomical sites, have already been described, characterized and used in therapeutic models for tissue repair. The umbilical cord mesenchymal stem cells, represented by cells from arteries and veins walls, as well as Wharton's jelly are easy to be obtained, highly available, require no invasive procedure, do not present risk to donors and do not present ethical limitation. The aim of this research was to analyze the plasticity of Wharton's jelly mesenchymal stem cells (WJ-MSCs) of goat, evaluating their behavior in vitro and characterizing them immunophenotypically. Thus, tests were performed on colony forming units, viability and cell growth curve, flow cytometry analysis and plasticity potential. Goat umbilical cord matrix cells exhibited fibroblastoid morphology with colony formation and self-renewal ability, always maintaining their undifferentiated state up to the eighth passage (P8). The growth curve kinetics exhibited the LAG, LOG, and DECAY phases, without displaying a PLATEAU phase. The plasticity assay demonstrated positive differentiation for osteogenic, adipogenic and chondrogenic lines, characterized by the synthesis of intracytoplasmic granules or extracellular matrix with the presence of calcium, lipids and proteoglycans. Flow cytometry demonstrated the expression of CD90 and CD105; absence of CD14 expression. It is concluded that the cell population isolated from the Wharton's jelly of goat constitutes a representative sample of mesenchymal stem cells, with great possibilities in the field of regenerative and reproductive medicine.
Assuntos
Células-Tronco Mesenquimais , Plasticidade Celular , Citometria de FluxoRESUMO
PURPOSE: To characterize bone marrow progenitors cells grown in vitro, using native goats from northeastern Brazil as animal model. METHODS: Ten northeastern Brazil native goats of both genders were used from the Piauí Federal University Agricultural Science Center's (UFPI) - Goat Farming Sector. Bone marrow aspirates where taken from the tibial ridge and seeded on culture plates for isolation, expansion and Flow Cytometry (expression markers - Oct-3/4, PCNA, Ck-Pan, Vimentina, Nanog). RESULTS: Progenitor cells showed colonies characterized by the presence of cell pellets with fibroblastoid morphology. Cell confluence was taken after 14 days culture and the non-adherent mononuclear cell progressive reduction. After the first passage, 94.36% cell viability was observed, starting from 4.6 x 106 cell/mL initially seeded. Cells that went through flow cytometry showed positive expression for Oct-3/4, PCNA, Ck-Pan, Vimentina, and Nanog. CONCLUSIONS: Bone marrow progenitor isolated of native goats from northeastern Brazil showed expression markers also seen in embryonic stem cells (Oct-3/4, Nanog), markers of cell proliferation (PCNA) and markers for mesenchymal cells (Vimentina and Ck-pan), which associated to morphological and culture growth features, suggest the existence of a mesenchymal stem cell (MSC) population in the goat bone marrow stromal cells studied.
Assuntos
Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Animais , Brasil , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Feminino , Citometria de Fluxo/métodos , Cabras , Masculino , Modelos Animais , Fator 3 de Transcrição de Octâmero/isolamento & purificação , Antígeno Nuclear de Célula em Proliferação/isolamento & purificação , Vimentina/isolamento & purificaçãoRESUMO
Stem cells are present in the adult tissues of most diverse species. Bone marrow is recognized to be the most exploited site to obtain stem cells and cell progenitors. The objective of the present study was to characterize hematopoietic progenitor (HP) morphology and analyze the performance of adherent cell progenitors (ACPs) cultivated in vitro from black-rumped agouti bone marrow (Dasyprocta prymnolopha). Bone marrow aspirates were obtained from tibia crest and used to prepare histological slides and identify cell morphology. Cells were also scattered on culture plates for later isolation, expansion, and quantification. Smears obtained from bone marrow demonstrated HPs at different stages of maturity. In culture, these cells showed fibroblastoid morphology and a strong tendency to form colonies, demonstrated by the presence of cell aggregates, cytoplasmic elongations lying side by side. An 80% cell confluence was observed at 18 days in culture and progressive reduction in the percentage of nonadherent mononuclear cells. After eight passes, a mean cell viability of 96.07% was observed, from a pool of 1.6 × 10(7) cells (ACP). Thirteen 25-cm(2) culture bottles were trypsinized, resuspended in freezing medium, stored in 14 criotubes at a concentration of 1 × 10(6) cells per milliliter, and placed in liquid nitrogen at -196°C. Agouti bone marrow demonstrated high plasticity, moreover different HP lines, and a population of adherent cells demonstrated morphology similar to mesenchymal stem cells in culture.
Assuntos
Roedores , Animais , Medula Óssea , Sobrevivência Celular , Células-Tronco Hematopoéticas/citologia , Células-Tronco Mesenquimais/citologia , MicroscopiaRESUMO
PURPOSE: To evaluate the effects of mesenchymal stem cells (MSC) from eight mice C57BL/6 gfp(+) bone marrows expanded in cultures associated with platelets rich plasma (PRP) deriving from another eight mice, in the repair of critical defects in calvarial bone produced in twenty-four adult isogenic mice C57BL/6. METHODS: The animals were submitted to a cranial defect of 6.0mm in diameter and divided into two equal experimental groups. Control group did not receive treatment and the treated group received a MSC pellet containing 1.0 x 10(7) cells/mL associated with 50.0 µL of plasma gel containing 1.0 x 10(9) autologous platelets within the defect. RESULTS: In the treated group was observed process of angiogenesis and bone repair better than control group. CONCLUSION: Mesenchymal stem cells derived from bone marrow of C57BL/6 gfp(+) mice associated with PRP gel applied in bone critical defects produced in calvarial contributes positively to the process of bone repair.
Assuntos
Células-Tronco Adultas/transplante , Células da Medula Óssea/fisiologia , Regeneração Óssea/fisiologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/fisiologia , Plasma Rico em Plaquetas/fisiologia , Crânio/cirurgia , Células-Tronco Adultas/ultraestrutura , Animais , Células da Medula Óssea/ultraestrutura , Células Cultivadas , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/genética , Masculino , Células-Tronco Mesenquimais/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Osteogênese/fisiologia , Distribuição Aleatória , Crânio/lesões , Crânio/ultraestrutura , Engenharia Tecidual/métodos , Transplante HomólogoRESUMO
PURPOSE: To characterize bone marrow progenitors cells grown in vitro, using native goats from northeastern Brazil as animal model. METHODS: Ten northeastern Brazil native goats of both genders were used from the Piauí Federal University Agricultural Science Center's (UFPI) - Goat Farming Sector. Bone marrow aspirates where taken from the tibial ridge and seeded on culture plates for isolation, expansion and Flow Cytometry (expression markers - Oct-3/4, PCNA, Ck-Pan, Vimentina, Nanog). RESULTS: Progenitor cells showed colonies characterized by the presence of cell pellets with fibroblastoid morphology. Cell confluence was taken after 14 days culture and the non-adherent mononuclear cell progressive reduction. After the first passage, 94.36% cell viability was observed, starting from 4.6 x 106 cell/mL initially seeded. Cells that went through flow cytometry showed positive expression for Oct-3/4, PCNA, Ck-Pan, Vimentina, and Nanog. CONCLUSIONS: Bone marrow progenitor isolated of native goats from northeastern Brazil showed expression markers also seen in embryonic stem cells (Oct-3/4, Nanog), markers of cell proliferation (PCNA) and markers for mesenchymal cells (Vimentina and Ck-pan), which associated to morphological and culture growth features, suggest the existence of a mesenchymal stem cell (MSC) population in the goat bone marrow stromal cells studied. .
Assuntos
Animais , Feminino , Masculino , Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Brasil , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Citometria de Fluxo/métodos , Cabras , Modelos Animais , /isolamento & purificação , Antígeno Nuclear de Célula em Proliferação/isolamento & purificação , Vimentina/isolamento & purificaçãoRESUMO
PURPOSE: To evaluate the effects of mesenchymal stem cells (MSC) from eight mice C57BL/6 gfp+ bone marrows expanded in cultures associated with platelets rich plasma (PRP) deriving from another eight mice, in the repair of critical defects in calvarial bone produced in twenty-four adult isogenic mice C57BL/6. METHODS: The animals were submitted to a cranial defect of 6.0mm in diameter and divided into two equal experimental groups. Control group did not receive treatment and the treated group received a MSC pellet containing 1.0 x 10(7) cells/mL associated with 50.0µL of plasma gel containing 1.0 x 10(9) autologous platelets within the defect. RESULTS: In the treated group was observed process of angiogenesis and bone repair better than control group. CONCLUSION: Mesenchymal stem cells derived from bone marrow of C57BL/6 gfp+ mice associated with PRP gel applied in bone critical defects produced in calvarial contributes positively to the process of bone repair.
OBJETIVO: Avaliar os efeitos da associação das células-tronco mesenquimais (MSC) oriundas da medula óssea de oito camundongos jovens C57BL/6 gfp+ e expandidas em culturas, com Plasma Rico em Plaquetas (PRP) provenientes de outros oito camundongos, na reparação de defeitos críticos confeccionados em calvária de 24 camundongos adultos C57BL/6. MÉTODOS: Os animais foram submetidos a um defeito craniano de 6,0mm de diâmetro e separados em dois grupos experimentais iguais. O grupo controle não recebeu tratamento e no grupo tratado foi administrado, no interior do defeito, pellet de MSC contendo 1,0 x 10(7) células/mL associado com 50,0µL de plasma em gel autólogo contendo 1,0 x 10(9) plaquetas. RESULTADOS: No grupo tratado verificou-se processo de angiogênese e reparação óssea superior ao grupo controle. CONCLUSÃO: A associação das células-tronco mesenquimais (MSC) derivadas da medula óssea de camundongos C57BL/6 gfp+ com gel de PRP aplicadas em defeitos ósseos críticos confeccionadas em calvária de camundongos C57BL/6 jovens, contribuiu positivamente para o processo de reparação óssea.
Assuntos
Animais , Masculino , Camundongos , Células-Tronco Adultas/transplante , Células da Medula Óssea/fisiologia , Regeneração Óssea/fisiologia , Células-Tronco Mesenquimais , Transplante de Células-Tronco Mesenquimais/métodos , Plasma Rico em Plaquetas/fisiologia , Crânio/cirurgia , Células-Tronco Adultas/ultraestrutura , Células da Medula Óssea/ultraestrutura , Células Cultivadas , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/genética , Células-Tronco Mesenquimais , Camundongos Transgênicos , Osteogênese/fisiologia , Distribuição Aleatória , Crânio/lesões , Crânio/ultraestrutura , Transplante Homólogo , Engenharia Tecidual/métodosRESUMO
Dentre todas as células-tronco estudadas até o presente momento, as mesenquimais (MSC) destacam-se por sua elevada plasticidade, podendo originar tecidos mesodermais e não mesodermais. Além disso, possuem características imunomoduladoras e imunossupressoras que ampliam as possibilidades de utilização terapêutica. As MSC secretam uma grande variedade de citocinas pró e anti-inflamatórias e fatores de crescimento e, por meio dessas moléculas bioativas, proporcionam a modulação da resposta inflamatória, o restabelecimento do suprimento vascular e a reparação adequada do tecido, contribuindo para a homeostasia tissular e imunológica sob condições fisiológicas. Também podem induzir as demais células presentes no nicho tecidual a secretarem outros fatores solúveis que estimulam a diferenciação dessas células indiferenciadas, favorecendo o processo de reparação. A terapia celular com MSC é uma alternativa terapêutica promissora, porém a compreensão da biologia dessas células ainda é uma ciência em formação. Este artigo tem por objetivo realizar uma breve revisão sobre as células mesenquimais indiferenciadas.
Of all the stem cells studied so far, the mesenchymal stem cells (MSC) stand out for their high plasticity and capacity of generating mesodermal and non-mesodermal tissues. In addition, immunomodulatory and immunosuppressive features that expand possibilities for therapeutic use are present in these cells. A variety of pro and anti-inflammatory cytokines and growth factors are secrete for MSC and provide a modulation of inflammatory response, re-establishment of vascular supply and adequate repair of the tissue, contributing to tissue homeostasis under physiologic conditions. Therefore, they can induce secretion of soluble factors that stimulate their differentiation by other cells present at the niche's tissue, promoting the repair process. Cell therapy using MSC is a promises therapeutic alternative, but understanding the biology of these cells is still under construction. The aim of the article is to conduct a short review of these undifferentiated mesenchymal cells.
RESUMO
No presente estudo, foram avaliados, de forma macro e microscópica, os resultados da aplicação do PRP em defeitos ósseos críticos de 6,0mm de diâmetro confeccionados em calvária de 24 camundongos isogênicos C57BL/6 jovens, separados em dois grupos experimentais. O grupo controle não recebeu tratamento, e no grupo tratado foram depositados, no interior do defeito, 50,0µL plasma em gel contendo 1,0x10(9) plaquetas. Constatou-se que o gel de PRP autólogo depositado em defeitos críticos contribuiu positivamente para o processo de reparação óssea, mormente na fase inicial.
This study aimed to evaluate macro and microscopic results after PRP application in bone critical defects of 6.0mm in diameter realized in cavarial of twenty-four young isogenic mice C57BL/6. Control group didn't receive treatment and in the treated group it was deposited 50.0µL of plasma gel containing 1.0x10(9) platelets in the defects. It was found that autologous PRP gel contributed positively to the bone repair process, especially in initial phase.