Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.625
Filtrar
1.
Bone Joint J ; 102-B(8): 1095-1106, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32731821

RESUMO

AIMS: Achilles tendon injuries are a frequent problem in orthopaedic surgery due to their limited healing capacity and the controversy surrounding surgical treatment. In recent years, tissue engineering research has focused on the development of biomaterials to improve this healing process. The aim of this study was to analyze the effect of tendon augmentation with a nanostructured fibrin-agarose hydrogel (NFAH) or genipin cross-linked nanostructured fibrin-agarose hydrogel (GP-NFAH), on the healing process of the Achilles tendon in rats. METHODS: NFAH, GP-NFAH, and MatriDerm (control) scaffolds were generated (five in each group). A biomechanical and cell-biomaterial-interaction characterization of these biomaterials was then performed: Live/Dead Cell Viability Assay, water-soluble tetrazolium salt-1 (WST-1) assay, and DNA-released after 48 hours. Additionally, a complete section of the left Achilles tendon was made in 24 Wistar rats. Animals were separated into four treatment groups (six in each group): direct repair (Control), tendon repair with MatriDerm, or NFAH, or GP-NFAH. Animals were euthanized for further histological analyses after four or eight weeks post-surgery. The Achilles tendons were harvested and a histopathological analysis was performed. RESULTS: Tensile test revealed that NFAH and GP-NFAH had significantly higher overall biomechanical properties compared with MatriDerm. Moreover, biological studies confirmed a high cell viability in all biomaterials, especially in NFAH. In addition, in vivo evaluation of repaired tendons using biomaterials (NFAH, GP-NFAH, and MatriDerm) resulted in better organization of the collagen fibres and cell alignment without clinical complications than direct repair, with a better histological score in GP-NFAH. CONCLUSION: In this animal model we demonstrated that NFAH and GP-NFAH had the potential to improve tendon healing following a surgical repair. However, future studies are needed to determine the clinical usefulness of these engineered strategies. Cite this article: Bone Joint J 2020;102-B(8):1095-1106.


Assuntos
Tendão do Calcâneo/cirurgia , Microambiente Celular/efeitos dos fármacos , Colágeno/uso terapêutico , Elastina/uso terapêutico , Regeneração/efeitos dos fármacos , Traumatismos dos Tendões/cirurgia , Tendão do Calcâneo/lesões , Animais , Materiais Biocompatíveis/farmacologia , Modelos Animais de Doenças , Fibrina/farmacologia , Hidrogéis/farmacologia , Masculino , Nanoestruturas , Distribuição Aleatória , Ratos , Ratos Wistar , Tendões/fisiologia , Engenharia Tecidual/métodos , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
3.
Nat Commun ; 11(1): 3250, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591525

RESUMO

Biocompatible polymers are widely used in tissue engineering and biomedical device applications. However, few biomaterials are suitable for use as long-term implants and these examples usually possess limited property scope, can be difficult to process, and are non-responsive to external stimuli. Here, we report a class of easily processable polyamides with stereocontrolled mechanical properties and high-fidelity shape memory behaviour. We synthesise these materials using the efficient nucleophilic thiol-yne reaction between a dipropiolamide and dithiol to yield an α,ß - unsaturated carbonyl moiety along the polymer backbone. By rationally exploiting reaction conditions, the alkene stereochemistry is modulated between 35-82% cis content and the stereochemistry dictates the bulk material properties such as tensile strength, modulus, and glass transition. Further access to materials possessing a broader range of thermal and mechanical properties is accomplished by polymerising a variety of commercially available dithiols with the dipropiolamide monomer.


Assuntos
Elastômeros/química , Fenômenos Mecânicos , Nylons/química , Materiais Inteligentes/química , Animais , Materiais Biocompatíveis/farmacologia , Varredura Diferencial de Calorimetria , Linhagem Celular , Masculino , Teste de Materiais , Camundongos , Nylons/síntese química , Polimerização , Ratos Sprague-Dawley , Estresse Mecânico , Compostos de Sulfidrila/química , Temperatura
4.
PLoS One ; 15(5): e0226791, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32374764

RESUMO

Over the past two decades, measurements of carbon nanotube toxicity and biodistribution have yielded a wide range of results. Properties such as nanotube type (single-walled vs. multi-walled), purity, length, aggregation state, and functionalization, as well as route of administration, greatly affect both the biocompatibility and biodistribution of carbon nanotubes. These differences suggest that generalizable conclusions may be elusive and that studies must be material- and application-specific. Here, we assess the short- and long-term biodistribution and biocompatibility of a single-chirality DNA-encapsulated single-walled carbon nanotube complex upon intravenous administration that was previously shown to function as an in-vivo reporter of endolysosomal lipid accumulation. Regarding biodistribution and fate, we found bulk specificity to the liver and >90% signal attenuation by 14 days in mice. Using near-infrared hyperspectral microscopy to measure single nanotubes, we found low-level, long-term persistence in organs such as the heart, liver, lung, kidney, and spleen. Measurements of histology, animal weight, complete blood count; biomarkers of organ function all suggest short- and long-term biocompatibility. This work suggests that carbon nanotubes can be used as preclinical research tools in-vivo without affecting acute or long-term health.


Assuntos
Materiais Biocompatíveis/farmacologia , Biomarcadores/sangue , Nanotecnologia , Nanotubos de Carbono/efeitos adversos , Animais , Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , DNA de Cadeia Simples/química , DNA de Cadeia Simples/farmacologia , Endossomos/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Camundongos , Nanotubos de Carbono/química , Imagem Óptica , Baço/efeitos dos fármacos , Baço/metabolismo , Distribuição Tecidual/efeitos dos fármacos
5.
PLoS One ; 15(4): e0231421, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32310981

RESUMO

Polymers are commonly used in medical device manufacturing, e.g. for drug delivery systems, bone substitutes and stent coatings. Especially hydrogels exhibit very promising properties in this field. Hence, the development of new hydrogel systems for customized application is of great interest, especially regarding the swelling behavior and mechanical properties as well as the biocompatibility. The aim of this work was the preparation and investigation of various polyelectrolyte and poly-ionic liquid based hydrogels accessible by radical polymerization. The obtained polymers were covalently crosslinked with N,N'-methylenebisacrylamide (MBAA) or different lengths of poly(ethyleneglycol)diacrylate (PEGDA). The effect of different crosslinker-to-monomer ratios has been examined. In addition to the compression curves and the maximum degree of swelling, the biocompatibility with L929 mouse fibroblasts of these materials was determined in direct cell seeding experiments and the outcome for the different hydrogels was compared.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Líquidos Iônicos/química , Acrilamidas/química , Animais , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Força Compressiva , Hidrogéis/farmacologia , Camundongos , Polietilenoglicóis/química
6.
Int J Nanomedicine ; 15: 2363-2378, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32308388

RESUMO

Biomaterials with porous structure and high surface area attract growing interest in biomedical research and applications. Aerogel-based biomaterials, as highly porous materials that are made from different sources of macromolecules, inorganic materials, and composites, mimic the structures of the biological extracellular matrix (ECM), which is a three-dimensional network of natural macromolecules (e.g., collagen and glycoproteins), and provide structural support and exert biochemical effects to surrounding cells in tissues. In recent years, the higher requirements on biomaterials significantly promote the design and development of aerogel-based biomaterials with high biocompatibility and biological activity. These biomaterials with multilevel hierarchical structures display excellent biological functions by promoting cell adhesion, proliferation, and differentiation, which are critical for biomedical applications. This review highlights and discusses the recent progress in the preparation of aerogel-based biomaterials and their biomedical applications, including wound healing, bone regeneration, and drug delivery. Moreover, the current review provides different strategies for modulating the biological performance of aerogel-based biomaterials and further sheds light on the current status of these materials in biomedical research.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Óssea , Sistemas de Liberação de Medicamentos/métodos , Cicatrização/efeitos dos fármacos , Animais , Regeneração Óssea/efeitos dos fármacos , Colágeno/química , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Humanos , Porosidade
7.
An Acad Bras Cienc ; 92(1): e20181120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32321020

RESUMO

the focus ofthis study was to testthe hypothesisthatthere would be no difference betweenthe biocompatibility of silicon dioxide nanofilms used as antimicrobial agents. Sixty male Wistar rats were divided into 4 groups (n=15): Group C (Control,Polyethylene), Group AR (Acrylic Resin), Group NP (Acrylic Resin coated with NP-Liquid), Group BG (Acrylic Resin coated with Bacterlon).the animals were sacrificed with 7,15 and 30 days and tissues analyzed as regardsthe events of inflammatory infiltrate, edema, necrosis, granulation tissue, mutinucleated giant cells, fibroblasts and collagen. Kruskal-Wallis and Dunn tests was used (P<0.05). Intense inflammatory infiltrate was shown mainly in Groups BG and AR, with significant difference from Control Group inthe time interval of 7days (P=0.004). Necrosis demonstrated significant difference between Group BG and Control Group (P<0.05) inthe time intervals of 7 days. For collagen fibers,there was significant difference betweenthe Control Group and Groups AR and BG inthe time interval of 7 days (P=0.006), and between BG and Control Groups inthe time intervals of 15 days (P=0.010).the hypothesis was rejected. Bacterlon demonstratedthe lowest level, and NP-Liquid Glassthe highest level of tissue compatibility, and best cell repair.the coating with NP-Liquid Glass was demonstrated to be highly promising for clinical use.


Assuntos
Resinas Acrílicas/farmacologia , Materiais Biocompatíveis/farmacologia , Edema/induzido quimicamente , Necrose/induzido quimicamente , Dióxido de Silício/farmacologia , Tela Subcutânea/patologia , Resinas Acrílicas/química , Animais , Materiais Biocompatíveis/química , Edema/patologia , Masculino , Teste de Materiais , Modelos Animais , Necrose/patologia , Ratos , Ratos Wistar , Dióxido de Silício/química , Tela Subcutânea/efeitos dos fármacos
8.
Acta Cir Bras ; 35(1): e202000102, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32215463

RESUMO

PURPOSE: To evaluate the local effect of simvastatin (SVT) combined with deproteinized bovine bone (DBB) with hydroxyapatite/ß-tricalcium phosphate biphasic ceramics (HA/TCP) and with collagen sponge (CS) on bone repair in critical size defects (CSDs) in rat calvaria. METHODS: Forty-two 5-mm diameter CSDs were made bilaterally in the calvaria of 18 rats. The animals were allocated according to the type of biomaterial and associations used to fill the CSD. After 8 weeks, the animals were euthanized, and their calvaria were evaluated for repaired tissue composition using histologic and histometric analyses. RESULTS: In the histometric analysis, the use of SVT showed to increase bone formation in the CSDs when combined with all the bone substitutes tested in this study (p<0.05). Greater bone formation was observed in the groups with SVT compared to the groups without SVT. CONCLUSIONS: The use of SVT without the need for a vehicle and combined with a commercially available biomaterial may be a cheaper way to potentiate the formation of bone tissue without the need to produce new biomaterials. Therefore, SVT combined with DBB induced significantly greater new bone formation than did the other treatments.


Assuntos
Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/farmacologia , Colágeno/farmacologia , Osteogênese/efeitos dos fármacos , Sinvastatina/farmacologia , Crânio/efeitos dos fármacos , Animais , Anticolesterolemiantes/farmacologia , Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo/métodos , Bovinos , Modelos Animais de Doenças , Feminino , Ratos , Ratos Wistar , Crânio/cirurgia
9.
Expert Rev Med Devices ; 17(5): 443-460, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32176853

RESUMO

Introduction: Traditional mechanical closure techniques pose many challenges including the risk of infection, tissue reaction, and injury to both patients and clinicians. There is an urgent need to develop tissue adhesive agents to reform closure technique. This review examined a variety of tissue adhesive agents available in the market in an attempt to gain a better understanding of intracorporal tissue adhesive agents as medical devices.Areas covered: Fundamental principles and clinical determinants of the tissue adhesives were summarized. The available tissue adhesives for intracorporal use and their relevant clinical evidence were then presented. Lastly, the perspective of future development for intracorporal tissue adhesive were discussed. Clinical evidence shows current agents are efficacious as adjunctive measures to mechanical closure and these agents have been trialed outside of clinical indications with varied results.Expert opinion: Despite some advancements in the development of tissue adhesives, there is still a demand to develop novel technologies in order to address unmet clinical needs, including low tensile strength in wet conditions, non-controllable polimerization and sub-optimal biocompatibility. Research trends focus on producing novel adhesive agents to remit these challenges. Examples include the development of biomimetic adhesives, externally activated adhesives, and multiple crosslinking strategies. Economic feasibility and biosafety are limiting factors for clinical implementation.


Assuntos
Adesivos Teciduais/farmacologia , Animais , Materiais Biocompatíveis/economia , Materiais Biocompatíveis/farmacologia , Humanos , Polímeros/farmacologia , Eletricidade Estática , Adesivos Teciduais/economia
10.
Int J Nanomedicine ; 15: 647-659, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099357

RESUMO

Background: Graphene and its derivatives have recently gained popularity in the biomedical field. Previous studies have confirmed that both the mechanical strength and wear resistance of graphene-containing polyethylene have been greatly improved. Therefore, it is being considered as an alternative for artificial joint replacement liners. Based on the literature, the wear debris generated from the traditional polymers used for orthopedic liners could lead to particle-induced osteolysis and, consequently, failure of joint replacement. However, the biological response of this novel graphene-based polymer is still unclear. Therefore, the current study aimed to investigate the in vitro and in vivo biological effects of graphene and graphene oxide (GO) particles on bone. Materials and Methods: The biological responses of graphene and GO particles were tested via in vitro and murine calvarial in vivo models. In the in vitro model, murine macrophage cells were mixed with particles and hydrogel and printed into two differently designed scaffolds; the induced proinflammatory cytokines were then tested. In the murine in vivo model, the particle size distribution was measured via SEM, and these particles were then administrated in the calvarial area, referring to our established model. A micro-CT and histological analysis were performed to examine the biological effects of the particles on bone health. The data were analyzed via the one-way analysis of variance to determine the differences between the groups. Results: Both graphene and GO induced significantly higher TNF-α and IL-6 secretion compared with the control in the three-dimensional in vitro model. In the murine calvarial in vivo test, the graphene and GO particles increased the bone mass compared with the sham groups in the micro-CT analysis. Bone formation was also observed in the histological analysis. Conclusion: In these in vivo and in vitro studies, the graphene and GO wear debris did not seem to induce harmful biological response effect to bone. Bone formation around the skull was observed in the calvarial model instead. Graphene-containing biomaterials could be a suitable new material for application in orthopedic prostheses due to their benefit of eliminating the risk of particle-induce osteolysis.


Assuntos
Grafite/farmacologia , Osteólise/tratamento farmacológico , Crânio/efeitos dos fármacos , Animais , Materiais Biocompatíveis/farmacologia , Feminino , Interleucina-6/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Osteogênese/efeitos dos fármacos , Osteólise/patologia , Tamanho da Partícula , Células RAW 264.7 , Crânio/citologia , Crânio/diagnóstico por imagem , Tecidos Suporte , Fator de Necrose Tumoral alfa/metabolismo , Microtomografia por Raio-X
11.
Sci Adv ; 6(3): eaay0065, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32010768

RESUMO

Triggerable materials capable of being degraded by selective stimuli stand to transform our capacity to precisely control biomedical device activity and performance while reducing the need for invasive interventions. Here, we describe the development of a modular and tunable light-triggerable hydrogel system capable of interfacing with implantable devices. We apply these materials to two applications in the gastrointestinal (GI) tract: a bariatric balloon and an esophageal stent. We demonstrate biocompatibility and on-demand triggering of the material in vitro, ex vivo, and in vivo. Moreover, we characterize performance of the system in a porcine large animal model with an accompanying ingestible LED. Light-triggerable hydrogels have the potential to be applied broadly throughout the GI tract and other anatomic areas. By demonstrating the first use of light-degradable hydrogels in vivo, we provide biomedical engineers and clinicians with a previously unavailable, safe, dynamically deliverable, and precise tool to design dynamically actuated implantable devices.


Assuntos
Trato Gastrointestinal/fisiologia , Hidrogéis/efeitos da radiação , Luz , Animais , Materiais Biocompatíveis/farmacologia , Células CACO-2 , Esôfago/fisiologia , Células HT29 , Humanos , Hidrogéis/síntese química , Stents , Suínos
12.
Carbohydr Polym ; 234: 115902, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070521

RESUMO

Injectable in situ gelling hydrogels are viable treatment options for meniscal injuries occurring in athletes. The present study aims to develop an injectable hydrogel via borax complexation of oxidized alginate, followed by a self-crosslinking reaction with gelatin through a Schiff's base reaction. Gelation kinetics and degree of crosslinking could be controlled by changing the concentration of components and the formation of Schiff ;'s base formation was confirmed by Raman spectroscopy. The injectable alginate dialdehyde-gelatin (15ADA20G) hydrogel showed 423 ±â€¯20 % water uptake, had an average pore size of 48 µm and compressive strength 295 ±â€¯32 kPa. Phase contrast images, scanning electron micrographs and actin staining depicted adhesion, profuse proliferation, and distribution of fibrochondrocytes on the hydrogel demonstrating its cytocompatibility. Application of hydrogel at the pig meniscal tear ex vivo showed good integration with the host meniscal tissue. Further, the histology of 15ADA20G hydrogel filled meniscus showed retention of hydrogel in the close proximity of meniscal tear even after 3days in culture. The self-crosslinking injectable hydrogel offers a niche for the growth of fibrochondrocytes.


Assuntos
Alginatos/farmacologia , Materiais Biocompatíveis/farmacologia , Reagentes para Ligações Cruzadas/farmacologia , Gelatina/farmacologia , Menisco/efeitos dos fármacos , Tecidos Suporte/química , Alginatos/síntese química , Alginatos/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Movimento Celular , Proliferação de Células , Reagentes para Ligações Cruzadas/síntese química , Reagentes para Ligações Cruzadas/química , Gelatina/síntese química , Gelatina/química , Oxirredução , Tamanho da Partícula , Propriedades de Superfície , Suínos , Engenharia Tecidual
13.
J Nanobiotechnology ; 18(1): 39, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32103765

RESUMO

BACKGROUND: The repair of large bone defects is a great challenge in clinical practice. In this study, copper-loaded-ZIF-8 nanoparticles and poly (lactide-co-glycolide) (PLGA) were combined to fabricate porous PLGA/Cu(I)@ZIF-8 scaffolds using three-dimensional printing technology for infected bone repair. METHODS: The surface morphology of PLGA/Cu(I)@ZIF-8 scaffolds was investigated by transmission electron microscopy and scanning electron microscopy. The PLGA/Cu(I)@ZIF-8 scaffolds were co-cultured with bacteria to determine their antibacterial properties, and with murine mesenchymal stem cells (MSCs) to explore their biocompatibility and osteoconductive properties. The bioactivity of the PLGA/Cu(I)@ZIF-8 scaffolds was evaluated by incubating in simulated body fluid. RESULTS: The results revealed that the PLGA/Cu(I)@ZIF-8 scaffolds had porosities of 80.04 ± 5.6% and exhibited good mechanical properties. When incubated with H2O2, Cu(I)@ZIF-8 nanoparticles resulted generated reactive oxygen species, which contributed to their antibacterial properties. The mMSCs cultured on the surface of PLGA/Cu(I)@ZIF-8 scaffolds were well-spread and adherent with a high proliferation rate, and staining with alkaline phosphatase and alizarin red was increased compared with the pure PLGA scaffolds. The mineralization assay showed an apatite-rich layer was formed on the surface of PLGA/Cu(I)@ZIF-8 scaffolds, while there was hardly any apatite on the surface of the PLGA scaffolds. Additionally, in vitro, Staphylococcus aureus cultured on the PLGA/Cu(I)@ZIF-8 scaffolds were almost all dead, while in vivo inflammatory cell infiltration and bacteria numbers were dramatically reduced in infected rats implanted with PLGA/Cu@ZIF-8 scaffolds. CONCLUSION: All these findings demonstrate that PLGA/Cu(I)@ZIF-8 scaffolds possess excellent antibacterial and osteoconductive properties, as well as good biocompatibility and high bioactivity. This study suggests that the PLGA/Cu(I)@ZIF-8 scaffolds could be used as a promising biomaterial for bone tissue engineering, especially for infected bone repair.


Assuntos
Antibacterianos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Nanocompostos/química , Impressão Tridimensional , Tecidos Suporte/química , Animais , Bactérias/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Adesão Celular , Peróxido de Hidrogênio , Células-Tronco Mesenquimais/metabolismo , Camundongos , Nanopartículas/química , Osteogênese , Porosidade , Engenharia Tecidual
14.
J Vis Exp ; (156)2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32090992

RESUMO

Corneal endothelial cell cultures have a tendency to undergo epithelial-to-mesenchymal transition (EMT) after loss of cell-to-cell contact. EMT is deleterious for the cells as it reduces their ability to form a mature and functional layer. Here, we present a method for establishing and subculturing human and sheep corneal endothelial cell cultures that minimizes the loss of cell-to-cell contact. Explants of corneal endothelium/Descemet's membrane are taken from donor corneas and placed into tissue culture under conditions that allow the cells to collectively migrate onto the culture surface. Once a culture has been established, the explants are transferred to fresh plates to initiate new cultures. Dispase II is used to gently lift clumps of cells off tissue culture plates for subculturing. Corneal endothelial cell cultures that have been established using this protocol are suitable for transferring to biomaterial membranes to produce tissue-engineered cell layers for transplantation in animal trials. A custom-made device for supporting biomaterial membranes during tissue culture is described and an example of a tissue-engineered graft composed of a layer of corneal endothelial cells and a layer of corneal stromal cells on either side of a collagen type I membrane is presented.


Assuntos
Materiais Biocompatíveis/farmacologia , Lâmina Limitante Posterior/metabolismo , Células Endoteliais/citologia , Epitélio Posterior/crescimento & desenvolvimento , Animais , Caderinas/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/metabolismo , Lâmina Limitante Posterior/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Ovinos , Doadores de Tecidos , Proteína da Zônula de Oclusão-1/metabolismo
15.
J Appl Oral Sci ; 28: e20190215, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31939521

RESUMO

OBJECTIVE: This study evaluated the angiogenesis-enhancing potential of a tricalcium silicate-based mineral trioxide aggregate (ProRoot MTA), Biodentine, and a novel bioceramic root canal sealer (Well-Root ST) in human dental pulp stem cells (hDPSCs), human periodontal ligament stem cells (hPLSCs), and human tooth germ stem cells (hTGSCs). METHODOLOGY: Dulbecco's modified Eagle's medium was conditioned for 24 h by exposure to ProRoot MTA, Biodentine, or Well-Root ST specimens (prepared according to the manufacturers' instructions). The cells were cultured in these conditioned media and their viability was assessed with 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium (MTS) on days 1, 3, 7, 10, and 14. Angiogenic growth factors [platelet-derived growth factor (PDGF), basic fibroblast growth factor (FGF-2), and vascular endothelial growth factor (VEGF)] were assayed by sandwich enzyme-linked immunosorbent assay (ELISA) on days 1, 7, and 14. Human umbilical vein endothelial cell (HUVEC) migration assays were used to evaluate the vascular effects of the tested materials at 6-8 h. Statistical analyses included Kruskal-Wallis, Mann-Whitney U, and Friedman and Wilcoxon signed rank tests. RESULTS: None of tricalcium silicate-based materials were cytotoxic and all induced a similar release of angiogenic growth factors (PDGF, FGF-2, and VEGF) (p>0.05). The best cell viability was observed for hDPSCs (p<0.05) with all tricalcium silicate-based materials at day 14. Tube formation by HUVECs showed a significant increase with all tested materials (p<0.05). CONCLUSION: The tricalcium silicate-based materials showed potential for angiogenic stimulation of all stem cell types and significantly enhanced tube formation by HUVECs.


Assuntos
Indutores da Angiogênese/farmacologia , Compostos de Cálcio/farmacologia , Cerâmica/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Células-Tronco/efeitos dos fármacos , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Fator 2 de Crescimento de Fibroblastos/análise , Fator 2 de Crescimento de Fibroblastos/efeitos dos fármacos , Citometria de Fluxo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Teste de Materiais , Neovascularização Fisiológica/efeitos dos fármacos , Ligamento Periodontal/citologia , Ligamento Periodontal/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Derivado de Plaquetas/efeitos dos fármacos , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Germe de Dente/citologia , Germe de Dente/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/análise , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos
16.
Carbohydr Polym ; 231: 115652, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888820

RESUMO

Hyaluronan (HA) have been widely used as the ideal biomaterials. It is important to understand their degradation and distribution for better optimization. From a new aspect of using radiotracers, we designed the HA-tyramine-bisphosphonate derivative for dual-labelling with two radionuclides (99mTc and 131I) simultaneously for in vitro and in vivo tracking. This dual-radiolabelled HA derivative can still be non-covalently crosslinked by hydroxyapatites to form injectable gel. The excellent properties of the gel, such as robust, biodegradable, and self-healing capacity were maintained. We firstly proved the possibility to distinguish different radionuclides in the degraded gel using the high-resolution gamma-ray spectrometry. The radiolabelled gel showed lower toxicity than pure hydroxyapatites against various cell lines, while the in vivo results proved that the 99mTc/131I-labelling of the gel was safe and stable enough for imaging and quantitatively tracking. The present method can also be applied for the development of dual-radiolabelled gels from other polysaccharides.


Assuntos
Meios de Contraste/farmacologia , Difosfonatos/química , Géis/química , Radioisótopos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Meios de Contraste/química , Difosfonatos/farmacologia , Raios gama , Géis/farmacologia , Humanos , Ácido Hialurônico/química , Radioisótopos do Iodo/química , Radioisótopos do Iodo/farmacologia , Radioisótopos/farmacologia , Análise Espectral , Tecnécio/química , Tecnécio/farmacologia , Engenharia Tecidual/métodos , Tiramina/química , Tiramina/farmacologia
17.
Carbohydr Polym ; 231: 115687, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888837

RESUMO

The intractable toxicity of cationic polymers limits their applicability in gene transport and controlled release. In consideration of the good biocompatibility and biofunctionality of dextran, herein we design and synthesize two types of amino group-containing cationic copolymers based on dextran by the copolymerization of cationic monomers from dextran backbones. Additionally, allyl crosslinkers containing disulfide bonds were introduced into polymerization, that made the copolymer crosslinked by disulfide. The resultant coacervates were formed from the self-assembly of cationic coplymers and anionic genes, and redox-responsive disulfide branch points endow coacervates with reducing environment responsiveness. The in vitro experiments showed that the dextran-based coacervates were sensitive to the reducing environment and underwent cleavage, which resulted in an effective release, uptake, and transfection of the genes by 293T cells. In addition, dextran-based coacervates can be used to carry siRNA into cancer cells with a high transfection efficiency, demonstrating their potential applicability in treatment against cancer.


Assuntos
Técnicas de Transferência de Genes , Neoplasias/genética , Polímeros/química , RNA Interferente Pequeno/genética , Ânions/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cátions/química , Proliferação de Células/genética , Dextranos/química , Dissulfetos/química , Células HEK293 , Humanos , Neoplasias/terapia , Oxirredução , Polímeros/farmacologia , RNA Interferente Pequeno/farmacologia , Transfecção
18.
Carbohydr Polym ; 231: 115709, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31888842

RESUMO

PolyElectrolyte Nanoparticles (PENs) obtained by layer-by-layer self-assembly of polycations/polyanions suffer from a lack of colloidal stability in physiological conditions. We report a simple innovative approach for increasing their stability by multiple ionic cross-linkers. Herein, a chitosan-based core was stabilized by polyanions such as tripolyphosphate and dextran sulfate at pHs of 3 (aPENs) and 8 (bPENs) to improve the quality of electrostatic interactions in the core and manage self-assembly of polyethyleneimine shell onto the core. The physicochemical properties of the particles were characterized by DLS, SEM, TEM, FT-IR, and TGA. TEM micrographs showed visible core/shell structures of bPENs. From particle size and polydispersity indices, the bPENs stability was salt concentration-dependent. The release profiles of PENs using nicotinic acid demonstrated sustained release in a pH-independent manner with a good fit of Korsmeyer-Peppas model. These results suggest that multiple ionic cross-linkers can be an efficient approach to increase the colloidal stability of PENs.


Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Polieletrólitos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Quitosana/farmacologia , Reagentes para Ligações Cruzadas/química , Sulfato de Dextrana/química , Humanos , Concentração de Íons de Hidrogênio , Íons/química , Tamanho da Partícula , Polieletrólitos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Mater Sci Eng C Mater Biol Appl ; 108: 110444, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924008

RESUMO

Effective treatment of cartilage defects represents a challenging problem, mainly due to the tissue's limited intrinsic self-repair capacity; the use of polymeric scaffolds as tissue substitute is rapidly increasing, but it is still limited by poor mechanical properties. Moreover, the onset of an infection can irreversibly affect the healing process. Accordingly, in this work we describe, for the first time, the preparation of composite scaffolds based on gellan gum, antibacterial Manuka honey and an inorganic clay (mesoporous silica, sodium­calcium bentonite or halloysite nanotubes). The surface composition, morphology, mechanical and biological features of such composites are herein assessed, aiming to optimize the composition of a superior scaffold for cartilage repair. Results demonstrated that after 45 days of in vitro incubation with human mesenchymal stem cells, the mesoporous silica-composite hydrogels exhibited significant changes in peak elastic and dynamic moduli over time thus demonstrating superior mechanical properties. Moreover, mesoporous silica provided the best performances in terms of in vitro cytocompatibility and antibacterial preventive activity in protection of cells in a co-culture model. Therefore, this selected composition was exploited for subcutaneous implantation in mice to investigate materials biocompatibility and infection prevention. Results demonstrated that composites did not cause severe immune response as well as they were able to restrain the infection. Accordingly, GG-MH-MS composites represent a very promising tool for cartilage tissue engineering.


Assuntos
Antibacterianos , Materiais Biocompatíveis , Cartilagem Articular , Mel , Hidrogéis , Polissacarídeos Bacterianos , Regeneração/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cartilagem Articular/lesões , Cartilagem Articular/fisiologia , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Teste de Materiais , Camundongos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Porosidade , Dióxido de Silício/química , Dióxido de Silício/farmacologia
20.
Carbohydr Polym ; 230: 115671, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887926

RESUMO

Cellulose-based materials are widely used in the biomedical field. However, the lack of antibacterial activities of cellulose fibers inevitably causes bacterial infection damages. In this study, Schiff base was first introduced to endow the cellulose fibers good antibacterial property and copper ions were complexed with Schiff base to form a complex. The prepared complex greatly enhanced the antibacterial properties of the cellulose fibers. FT-IR, XRD, UV-vis and SEM-EDS results proved the successful synthesis of Schiff base and its copper (II) complex. The antibacterial tests indicated that the width of the inhibition zone of the as-prepared cellulose-based Schiff base-Cu (II) complex against E. coli and S. aureus increased by 472 % and 823 %, respectively, in comparison to the Schiff base ligand. This significant increase could be attributed to the incorporation of the copper ions (II). This Schiff base-Cu (II) complex containing cellulose-based antibacterial materials are expected to be widely used for biomedical application.


Assuntos
Antibacterianos/farmacologia , Celulose/farmacologia , Complexos de Coordenação/farmacologia , Cobre/farmacologia , Bases de Schiff/farmacologia , Bandagens , Materiais Biocompatíveis/farmacologia , Celulose/química , Escherichia coli/efeitos dos fármacos , Bases de Schiff/química , Staphylococcus aureus/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA