Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.938
Filtrar
1.
AAPS PharmSciTech ; 22(3): 76, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33595780

RESUMO

Collagen and chitosan have haemostatic, tissue fix and wound healing properties but the poor mechanical property limits their application. Therefore, various concentrations of collagen (1-6%) and chitosan (1-2%) were used to develop biopolymer-coated gauzes, with and without glycerol as plasticiser. Glycerol-treated gauzes showed desired mechanical and adhesive property in comparison to polymer-coated gauzes alone. Developed gauzes were characterized using differential scanning calorimetry, thermal gravimetric analysis and Fourier transform infrared spectrophotometry to confirm the biopolymer coating and stability. Scanning electron microscopy showed multilayer coating of the biopolymer and faster clotting in chitosan gauzes in comparison to collagen. Surface plasmon resonance assay confirmed that chitosan exhibited more binding affinity of 65 RU in comparison to collagen, which showed 55 RU with erythrocytes. Decrease in the value of plateletcrit and mean platelet volume confirmed platelet adhesion and aggregation over the surface of polymer-coated dressings. Gamma scintigraphy studies showed 85 ± 2% formulation retention up to 12 h at the wound site in comparison to 40 ± 3% retention of the radiopharmaceutical alone. Collagen and chitosan-coated gauze showed 226 ± 15 s and 179 ± 12 s haemostasis time, respectively, which was significantly less from 506 ± 15 s in standard gauze. Chitosan gauze showed faster wound healing in comparison to the collagen-coated gauze. Chitosan and collagen-coated gauzes showed 55 ± 4% wound contraction on day seven in comparison to 25 ± 2% in the control group, while chitosan gauzes showed complete wound contraction on day fourteenth, while the collagen-coated gauze showed 90 ± 3% on the same day.


Assuntos
Bandagens , Quitosana/farmacologia , Colágeno/farmacologia , Hemostáticos/farmacologia , Cicatrização/efeitos dos fármacos , Adulto , Animais , Biopolímeros/farmacologia , Humanos , Masculino , Ratos , Ratos Sprague-Dawley
2.
J Vis Exp ; (167)2021 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-33554972

RESUMO

Despite several advances in cardiac tissue engineering, one of the major challenges to overcome remains the generation of a fully functional vascular network comprising several levels of complexity to provide oxygen and nutrients within bioengineered heart tissues. Our laboratory has developed a three-dimensional in vitro model of the human heart, known as the "cardiac spheroid" or "CS". This presents biochemical, physiological, and pharmacological features typical of the human heart and is generated by co-culturing its three major cell types, such as cardiac myocytes, endothelial cells, and fibroblasts. Human induced pluripotent stem cells-derived cardiomyocytes (hiPSC-CMs or iCMs) are co-cultured at ratios approximating the ones found in vivo with human cardiac fibroblasts (HCFs) and human coronary artery endothelial cells (HCAECs) in hanging drop culture plates for three to four days. The confocal analysis of CSs stained with antibodies against cardiac Troponin T, CD31 and vimentin (markers for cardiac myocytes, endothelial cells and fibroblasts, respectively) shows that CSs present a complex endothelial cell network, resembling the native one found in the human heart. This is confirmed by the 3D rendering analysis of these confocal images. CSs also present extracellular matrix (ECM) proteins typical of the human heart, such as collagen type IV, laminin and fibronectin. Finally, CSs present a contractile activity measured as syncytial contractility closer to the one typical of the human heart compared to CSs that contain iCMs only. When treated with a cardiotoxic anti-cancer agent, such as doxorubicin (DOX, used to treat leukemia, lymphoma and breast cancer), the viability of DOX-treated CSs is significantly reduced at 10 µM genetic and chemical inhibition of endothelial nitric oxide synthase, a downstream target of DOX in HCFs and HCAECs, reduced its toxicity in CSs. Given these unique features, CSs are currently used as in vitro models to study heart biochemistry, pathophysiology, and pharmacology.


Assuntos
Bioengenharia/métodos , Coração/fisiopatologia , Esferoides Celulares/citologia , Animais , Cardiotoxinas/farmacologia , Contagem de Células , Separação Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Colágeno/farmacologia , Doxorrubicina/farmacologia , Doxorrubicina/toxicidade , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Fibroblastos/citologia , Géis , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Fixação de Tecidos
3.
J Vis Exp ; (167)2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33586705

RESUMO

The invasion of cancer cells from the primary tumor into the adjacent healthy tissues is an early step in metastasis. Invasive cancer cells pose a major clinical challenge because no efficient method exist for their elimination once their dissemination is underway. A better understanding of the mechanisms regulating cancer cell invasion may lead to the development of novel potent therapies. Due to their physiological resemblance to tumors, spheroids embedded in collagen I have been extensively utilized by researchers to study the mechanisms governing cancer cell invasion into the extracellular matrix (ECM). However, this assay is limited by (1) a lack of control over the embedding of spheroids into the ECM; (2) high cost of collagen I and glass bottom dishes, (3) unreliable immunofluorescent labeling, due to the inefficient penetration of antibodies and fluorescent dyes and (4) time-consuming image processing and quantification of the data. To address these challenges, we optimized the three-dimensional (3D) spheroid protocol to image fluorescently labeled cancer cells embedded in collagen I, either using time-lapse videos or longitudinal imaging, and analyze cancer cell invasion. First, we describe the fabrication of a spheroid imaging device (SID) to embed spheroids reliably and in a minimal collagen I volume, reducing the assay cost. Next, we delineate the steps for robust fluorescence labeling of live and fixed spheroids. Finally, we offer an easy-to-use Fiji macro for image processing and data quantification. Altogether, this simple methodology provides a reliable and affordable platform to monitor cancer cell invasion in collagen I. Furthermore, this protocol can be easily modified to fit the users' needs.


Assuntos
Imageamento Tridimensional , Imagem Óptica , Esferoides Celulares/patologia , Animais , Bovinos , Linhagem Celular Tumoral , Colágeno/farmacologia , Fluorescência , Imunofluorescência , Camundongos , Invasividade Neoplásica , Coloração e Rotulagem , Fatores de Tempo
4.
J Vis Exp ; (167)2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33491677

RESUMO

Cancer microenvironment has a significant impact on the progression of the disease. In particular, hypoxia is the key driver of cancer survival, invasion, and chemoresistance. Although several in vitro models have been developed to study hypoxia-related cancer pathology, the complex interplay of the cancer microenvironment observed in vivo has not been reproduced yet owing to the lack of precise spatial control. Instead, 3D biofabrication approaches have been proposed to create microphysiological systems for better emulation of cancer ecology and accurate anticancer treatment evaluation. Herein, we propose a 3D cell-printing approach to fabricate a hypoxic cancer-on-a-chip. The hypoxia-inducing components in the chip were determined based on a computer simulation of the oxygen distribution. Cancer-stroma concentric rings were printed using bioinks containing glioblastoma cells and endothelial cells to recapitulate a type of solid cancer. The resulting chip realized central hypoxia and aggravated malignancy in cancer with the formation of representative pathophysiological markers. Overall, the proposed approach for creating a solid-cancer-mimetic microphysiological system is expected to bridge the gap between in vivo and in vitro models for cancer research.


Assuntos
Progressão da Doença , Dispositivos Lab-On-A-Chip , Neoplasias/patologia , Impressão Tridimensional , Hipóxia Tumoral , Linhagem Celular Tumoral , Sobrevivência Celular , Colágeno/farmacologia , Simulação por Computador , Criopreservação , Dimetilpolisiloxanos/química , Células Endoteliais/patologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Células Estromais/patologia , Microambiente Tumoral
5.
PLoS One ; 15(12): e0236681, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33315857

RESUMO

Mechanical loading affects tendon healing and recovery. However, our understanding about how physical loading affects recovery of viscoelastic functions, collagen production and tissue organisation is limited. The objective of this study was to investigate how different magnitudes of loading affects biomechanical and collagen properties of healing Achilles tendons over time. Achilles tendon from female Sprague Dawley rats were cut transversely and divided into two groups; normal loading (control) and reduced loading by Botox (unloading). The rats were sacrificed at 1, 2- and 4-weeks post-injury and mechanical testing (creep test and load to failure), small angle x-ray scattering (SAXS) and histological analysis were performed. The effect of unloading was primarily seen at the early time points, with inferior mechanical and collagen properties (SAXS), and reduced histological maturation of the tissue in unloaded compared to loaded tendons. However, by 4 weeks no differences remained. SAXS and histology revealed heterogeneous tissue maturation with more mature tissue at the peripheral region compared to the center of the callus. Thus, mechanical loading advances Achilles tendon biomechanical and collagen properties earlier compared to unloaded tendons, and the spatial variation in tissue maturation and collagen organization across the callus suggests important regional (mechano-) biological activities that require more investigation.


Assuntos
Tendão do Calcâneo/fisiopatologia , Fenômenos Biomecânicos/fisiologia , Traumatismos dos Tendões/fisiopatologia , Cicatrização/fisiologia , Tendão do Calcâneo/efeitos dos fármacos , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Toxinas Botulínicas Tipo A/fisiologia , Colágeno/farmacologia , Modelos Animais de Doenças , Feminino , Ratos , Ratos Sprague-Dawley , Espalhamento a Baixo Ângulo , Estresse Mecânico , Traumatismos dos Tendões/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Difração de Raios X/métodos
6.
PLoS One ; 15(12): e0244301, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33338083

RESUMO

Adhesion and scarring after neural surgery are detrimental to nerve regeneration and functional recovery. Amniotic membranes have been used in tissue repair due to their immunogenicity and richness in cytokines. In this study, an electrospun polycaprolactone (PCL)-amnion nanofibrous membrane was prepared for the treatment of sciatic nerve compression in a rat model. The effects of the PCL-amnion nanofibrous membrane on the prevention of adhesion formation and nerve regeneration were evaluated using electrophysiology and histological analyses. Compared with the medical chitosan hydrogel dressing, the PCL-amnion nanofibrous membrane significantly reduced peripheral nerve adhesion and promoted the rapid recovery of nerve conduction. Moreover, the immunohistochemical analysis identified more Schwann cells and less pro-inflammatory M1 macrophages in the PCL-amnion group. Western blot and RT-PCR results showed that the expression levels of type-Ⅰ and Ⅲ collagen in the PCL-treated rats were half of those in the control group after 12 weeks, while the expression level of nerve growth factor was approximately 3.5 times that found in the rats treated with medical chitosan hydrogel. In summary, electrospun PCL-amnion nanofibrous membranes can effectively reduce adhesion after neural surgery and promote nerve repair and regeneration. The long-term retention in vivo and sustained release of cytokines make PCL-amnion a promising biomaterial for clinical application.


Assuntos
Regeneração Nervosa/efeitos dos fármacos , Poliésteres/farmacologia , Aderências Teciduais/prevenção & controle , Âmnio/patologia , Animais , Materiais Biocompatíveis , Quitosana/farmacologia , Colágeno/farmacologia , Modelos Animais de Doenças , Hidrogéis/farmacologia , Masculino , Nanofibras/química , Ratos , Ratos Sprague-Dawley , Células de Schwann/patologia , Nervo Isquiático/patologia , Neuropatia Ciática/fisiopatologia , Aderências Teciduais/tratamento farmacológico , Engenharia Tecidual/métodos , Tecidos Suporte
7.
Acta Cir Bras ; 35(3): e202000303, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32490900

RESUMO

PURPOSE: To evaluate the in vivo response of photobiomodulation therapy associated with norbixin-based poly(hydroxybutyrate) membrane (PHB) in tenotomized calcaneal tendon. METHODS: Thirty rats were randomly allocated to six groups (n=5 each): LED groups (L1, L2 and L3) and membrane + LED groups (ML1, ML2 and ML3). The right calcaneal tendons of all animals were sectioned transversely and were irradiated with LED daily, one hour after surgery every 24 hours, until the day of euthanasia. At the end of the experiments the tendons were removed for histological analysis. RESULTS: The histological analysis showed a significant reduction in inflammatory cells in the ML1, ML2 and ML3 groups (p=0.0056, p=0.0018 and p<0.0001, respectively) compared to those in the LED group. There was greater proliferation of fibroblasts in the ML1 (p<0.0001) and L3 (p<0.0001) groups. A higher concentration of type I collagen was also observed in the ML1 group (p=0.0043) replacing type III collagen. CONCLUSION: Photobiomodulation in association with norbixin-based PHB membrane led to control of the inflammatory process. However, it did not favor fibroblast proliferation and did not optimize type I collagen formation in the expected stage of the repair process.


Assuntos
Tendão do Calcâneo/efeitos da radiação , Carotenoides/farmacologia , Hidroxibutiratos/farmacologia , Terapia com Luz de Baixa Intensidade/métodos , Tendinopatia/radioterapia , Tenotomia/métodos , Tendão do Calcâneo/efeitos dos fármacos , Tendão do Calcâneo/cirurgia , Animais , Colágeno/farmacologia , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Colágeno Tipo III/análise , Colágeno Tipo III/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Fibroblastos/química , Fibroblastos/efeitos dos fármacos , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Cicatrização/efeitos dos fármacos , Cicatrização/efeitos da radiação
8.
PLoS One ; 15(6): e0234638, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32569325

RESUMO

Hematopoietic stem cell transplantation is successfully applied since the late 1950s; however, its efficacy still needs to be increased. A promising strategy is to transplant high numbers of pluripotent hematopoietic stem cells (HSCs). Therefore, an improved ex vivo culture system that supports proliferation and maintains HSC pluripotency would override possible limitations in cell numbers gained from donors. To model the natural HSC niche in vitro, we optimized the HSC medium composition with a panel of cytokines and valproic acid and used an artificial 3D bone marrow-like scaffold made of polydimethylsiloxane (PDMS). This 3D scaffold offered a suitable platform to amplify human HSCs in vitro and, simultaneously, to support their viability, multipotency and ability for self-renewal. Silicon oxide-covering of PDMS structures further improved amplification of CD34+ cells, although the conservation of naïve HSCs was better on non-covered 3D PDMS. Finally, we found that HSC cultivated on non-covered 3D PDMS generated most pluripotent colonies within colony forming unit assays. In conclusion, by combining biological and biotechnological approaches, we optimized in vitro HSCs culture conditions, resulting in improved amplification, multipotency maintenance and vitality of HSCs.


Assuntos
Materiais Biomiméticos/farmacologia , Células-Tronco Hematopoéticas/citologia , Nicho de Células-Tronco , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Colágeno/farmacologia , Dimetilpolisiloxanos/farmacologia , Feminino , Fibronectinas/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Masculino , Purinas/farmacologia , Nicho de Células-Tronco/efeitos dos fármacos , Ácido Valproico/farmacologia
9.
Gynecol Obstet Invest ; 85(3): 267-276, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32289792

RESUMO

BACKGROUND: Intrauterine adhesion (IUA) is the second leading cause of secondary infertility in women. Research has shown that stem cells can promote endometrial regeneration and that biomaterials are also helpful in tissue regeneration. Therefore, we compared the efficacy of a collagen scaffold combined with either human umbilical cord mesenchymal stem cells (hUCMSC) or estrogen for the treatment of IUA. METHODS: The IUA-induced rats were injected with hUCMSCs or estrogen, and with a collagen scaffold. The endometrial glands and amount of fibrosis were assessed using hematoxylin and eosin and Masson staining. The extent of fibrosis and levels of regeneration-related cytokines were examined by real-time quantitative PCR, and the expression levels of the estrogen receptor, KI67 and cytokeratin were analyzed using an immunochemistry assay. In addition, human nuclear antigen (HuNu) and vimentin were examined by immunofluorescence microscopy. RESULTS: The collagen scaffold administered with hUCMSCs markedly increased the number of endometrial glands and reduced the area of fibrosis compared with either the collagen scaffold or hUCMSCs alone. In addition, the collagen scaffold with hUCMSCs significantly regulated the expression levels of fibrosis, estrogen, and differentiation-related genes relative to the collagen scaffold or hUCMSCs alone. Furthermore, the hUCMSCs alone or in combination with the collagen scaffold increased the expression of HuNu and vimentin in the IUA-induced rat model. In addition, protein levels of the p-transcriptional co-activator with PDZ-binding motif, stromal cell-derived factor-1, and C-X-C chemokine receptor type 4 were upregulated in the group that received the collagen scaffold in combination with -hUCMSCs. CONCLUSION: Our results suggest that the combination of the collagen scaffold with hUCMSCs may be an alternative approach for treating IUA.


Assuntos
Regeneração Tecidual Guiada/métodos , Transplante de Células-Tronco Mesenquimais , Aderências Teciduais/terapia , Tecidos Suporte/química , Doenças Uterinas/terapia , Animais , Colágeno/farmacologia , Modelos Animais de Doenças , Endométrio/fisiologia , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Ratos , Cordão Umbilical/citologia
10.
J Bone Miner Metab ; 38(5): 639-647, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32303916

RESUMO

INTRODUCTION: Collagen from marine esponges has been used as a promising material for tissue engineering proposals. Similarly, photobiomodulation (PBM) is able of modulating inflammatory processes after an injury, accelerating soft and hard tissue healing and stimulating neoangiogenesis. However, the effects of the associated treatments on bone tissue healing have not been studied yet. In this context, the present study aimed to evaluate the biological temporal modifications (using two experimental periods) of marine sponge collagen or sponging (SPG) based scaffold and PBM on newly formed bone using a calvaria bone defect model. MATERIAL AND METHODS: Wistar rats were distributed into two groups: SPG or SPG/PBM and euthanized into two different experimental periods (15 and 45 days post-surgery). A cranial critical bone defect was used to evaluate the effects of the treatments. Histology, histomorfometry and immunohistological analysis were performed. RESULTS: Histological findings demonstrated that SPG/PBM-treated animals, 45 days post-surgery, demonstrated a higher amount of connective and newly formed bone tissue at the region of the defect compared to CG. Notwithstanding, no difference among groups were observed in the histomorphometry. Interestingly, for both anti-transforming growth factor-beta (TGF-ß) and anti-vascular endothelial growth factor (VEGF) immunostaining, higher values for SPG/PBM, at 45 days post-surgery could be observed. CONCLUSION: It can be concluded that the associated treatment can be considered as a promising therapeutical intervention.


Assuntos
Organismos Aquáticos/química , Colágeno/farmacologia , Terapia com Luz de Baixa Intensidade , Crânio/patologia , Tecidos Suporte/química , Cicatrização/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Masculino , Ratos Wistar , Crânio/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
Nat Commun ; 11(1): 2054, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345968

RESUMO

Classical dendritic cells (cDCs) are rare sentinel cells specialized in the regulation of adaptive immunity. Modeling cDC development is crucial to study cDCs and harness their therapeutic potential. Here we address whether cDCs could differentiate in response to trophic cues delivered by mesenchymal components of the hematopoietic niche. We find that mesenchymal stromal cells engineered to express membrane-bound FLT3L and stem cell factor (SCF) together with CXCL12 induce the specification of human cDCs from CD34+ hematopoietic stem and progenitor cells (HSPCs). Engraftment of engineered mesenchymal stromal cells (eMSCs) together with CD34+ HSPCs creates an in vivo synthetic niche in the dermis of immunodeficient mice driving the differentiation of cDCs and CD123+AXL+CD327+ pre/AS-DCs. cDC2s generated in vivo display higher levels of resemblance with human blood cDCs unattained by in vitro-generated subsets. Altogether, eMSCs provide a unique platform recapitulating the full spectrum of cDC subsets enabling their functional characterization in vivo.


Assuntos
Células Dendríticas/citologia , Nicho de Células-Tronco , Animais , Biomarcadores/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Quimiocina CXCL12/farmacologia , Análise por Conglomerados , Colágeno/farmacologia , Células Dendríticas/efeitos dos fármacos , Combinação de Medicamentos , Humanos , Laminina/farmacologia , Proteínas de Membrana/metabolismo , Camundongos , Organoides/efeitos dos fármacos , Organoides/metabolismo , Proteoglicanas/farmacologia , Nicho de Células-Tronco/efeitos dos fármacos , Células Estromais/citologia , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo
12.
Tissue Cell ; 63: 101326, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32223953

RESUMO

OBJECTIVES: We aim to develop a 3D-bilayer collagen (COL) membrane reinforced with nano beta-tricalcium-phosphate (nß-TCP) particles and to evaluate its bone regeneration in combination with leukocyte-platelet-rich fibrin (L-PRF) in vivo. BACKGROUND DATA: L-PRF has exhibited promising results as a cell carrier in bone regeneration in a number of clinical studies, however there are some studies that did not confirm the positive results of L-PRF application. METHODS: Mechanical & physiochemical characteristics of the COL/nß-TCP membrane (1/2 & 1/4) were tested. Proliferation and osteogenic differentiation of seeded cells on bilayer collagen/nß-TCP thick membrane was examined. Then, critical-sized calvarial defects in 8 white New Zealand rabbits were filled with either Col, Col/nß-TCP, Col/nß-TCP combined with L-PRF membrane, or left empty. New bone formation (NBF) was measured histomorphometrically 4 & 8 weeks postoperatively. RESULTS: Compressive modulus increases while porosity decreases with higher ß-TCP concentrations. Mechanical properties improve, with 89 % porosity (pore size ∼100 µm) in the bilayer-collagen/nß-TCP membrane. The bilayer design also enhances the proliferation and ALP activity. In vivo study shows no significant difference among test groups at 4 weeks, but Col/nß-TCP + L-PRF demonstrates more NBF compared to others (P < 0.05) after 8 weeks. CONCLUSION: The bilayer-collagen/nß-TCP thick membrane shows promising physiochemical in vitro results and significant NBF, as ¾ of the defect is filled with lamellar bone when combined with L-PRF membrane.


Assuntos
Doenças Ósseas/terapia , Regeneração Óssea/genética , Colágeno/farmacologia , Fibrina Rica em Plaquetas/metabolismo , Animais , Doenças Ósseas/genética , Doenças Ósseas/patologia , Colágeno/química , Humanos , Leucócitos/metabolismo , Membranas/química , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Fibrina Rica em Plaquetas/química , Coelhos
13.
Cytotherapy ; 22(5): 247-260, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32234290

RESUMO

The process of wound healing restores skin homeostasis but not full functionality; thus, novel therapeutic strategies are needed to accelerate wound closure and improve the quality of healing. In this context, tissue engineering and cellular therapies are promising approaches. Although sharing essential characteristics, mesenchymal stromal cells (MSCs) isolated from different tissues might have distinct properties. Therefore, the aim of this study was to comparatively investigate, by a mouse model in vivo assay, the potential use of dermal-derived MSCs (DSCs) and adipose tissue-derived MSCs (ASCs) in improving skin wound healing. Human DSCs and ASCs were delivered to full-thickness mouse wounds by a collagen-based scaffold (Integra Matrix). We found that the association of both DSCs and ASCs with the Integra accelerated wound closure in mice compared with the biomaterial only (control). Both types of MSCs stimulated angiogenesis and extracellular matrix remodeling, leading to better quality scars. However, the DSCs showed smaller scar size,superior extracellular matrix deposition, and greater number of cutaneous appendages. Besides, DSCs and ASCs reduced inflammation by induction of macrophage polarization from a pro-inflammatory (M1) to a pro-repair (M2) phenotype. In conclusion, both DSCs and ASCs were able to accelerate the healing of mice skin wounds and promote repair with scars of better quality and more similar to healthy skin than the empty scaffold. DSCs associated with Integra induced superior overall results than the Integra alone, whereas scaffolds with ASCs showed an intermediate effect, often not significantly better than the empty biomaterial.


Assuntos
Tecido Adiposo/citologia , Polaridade Celular/genética , Macrófagos/metabolismo , Transplante de Células-Tronco Mesenquimais/métodos , Fenótipo , Pele/citologia , Cicatrização , Adulto , Animais , Colágeno/farmacologia , Modelos Animais de Doenças , Matriz Extracelular/metabolismo , Feminino , Voluntários Saudáveis , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neovascularização Fisiológica , Pele/lesões , Engenharia Tecidual/métodos , Adulto Jovem
14.
Eur J Med Chem ; 192: 112187, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32155530

RESUMO

Cardiovascular diseases are the leading cause of death in the world. Platelets have a major role in cardiovascular events as they bind to the damaged endothelium activating and forming thrombi. Although some hydroquinone scaffold-containing compounds have known antiplatelet activities, currently there is a lack of evidence on the antiplatelet activity of hydroquinones carrying electron attractor groups. In this work, we evaluate the antiplatelet effect of a series of ortho-carbonyl hydroquinone derivatives on cytotoxicity and function of human platelets, using collagen and thrombin receptor activator peptide 6 (TRAP-6) as agonists. Our structure-activity relationship study shows that gem-diethyl/methyl substitutions and the addition/modifications of the third ring of ortho-carbonyl hydroquinone scaffold influence on the selective index (IC50 TRAP-6/IC50 Collagen) and the inhibitory capacity of platelet aggregation. Compounds 3 and 8 inhibit agonist-induced platelet aggregation in a non-competitive manner with IC50 values of 1.77 ± 2.09 µM (collagen) and 11.88 ± 4.59 µM (TRAP-6), respectively and show no cytotoxicity. Both compounds do not affect intracellular calcium levels and mitochondrial bioenergetics. Consistently, they reduce the expression of P-selectin, activation of glycoprotein IIb/IIIa, and release of adenosine triphosphate and CD63 from platelet. Our findings may be used for further development of new drugs in platelet-related thrombosis diseases.


Assuntos
Colágeno/farmacologia , Hidroquinonas/farmacologia , Fragmentos de Peptídeos/farmacologia , Inibidores da Agregação de Plaquetas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colágeno/química , Relação Dose-Resposta a Droga , Voluntários Saudáveis , Humanos , Hidroquinonas/síntese química , Hidroquinonas/química , Estrutura Molecular , Fragmentos de Peptídeos/química , Inibidores da Agregação de Plaquetas/síntese química , Inibidores da Agregação de Plaquetas/química , Relação Estrutura-Atividade
15.
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
16.
Eur J Vasc Endovasc Surg ; 59(4): 635-641, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32094049

RESUMO

OBJECTIVE: The aim of this study was to assess the effectiveness of gentamicin containing collagen implants in the reduction of surgical site infections (SSIs) in patients undergoing an inguinal incision for vascular surgery. METHODS: Prospective blinded randomised controlled multicentre trial (RCT), performed in four hospitals in The Netherlands and Belgium. This study included 288 patients who underwent an inguinal incision for primary arterial repair (femoral endarterectomy, femorofemoral or femoropopliteal bypass, aortobifemoral bypass, thrombectomy, embolectomy, endovascular aneurysm repair) between October 2012 and December 2015. Patients were randomised to receive a gentamicin implant (study group) or no implant (control group). The calculated sample sizes of 304 patients per group were not reached. Primary outcome was SSI incidence after six weeks. Secondary outcomes were time to onset of infection, length of hospital stay, allergic reactions, treatment with antibiotics, need for re-admission, re-operation and mortality. RESULTS: One hundred fifty-one patients were allocated to the study group (mean age 69 ± 9.2 years) and 137 patients were allocated to the control group (mean age 70 ± 10.4 years). Both groups were homogeneous regarding baseline and intra-operative characteristics. Gentamicin implants did not result in a significant overall reduction of SSIs in the study group (7% vs. 12%, p = .17). In a post hoc analysis comparing two study sites with low (<10%) and two study sites with high (>10%) infection rates in the control group, gentamicin implants significantly reduced SSIs in high risk centres (22% vs. 1%, p < .001), whereas there was no significant effect in low risk centres (13% vs. 7%, p = .30). There were no allergic reactions and all secondary outcomes were comparable between groups. CONCLUSION: Gentamicin implants did not result in a significant overall reduction of SSIs in this RCT. Gentamicin implants did reduce the incidence of SSIs in high risk centres and may be a valuable adjunct to improve outcomes in such vascular centres with a high incidence of wound infections. However, the limitation of not reaching the calculated sample sizes should be considered.


Assuntos
Antibacterianos/farmacologia , Aneurisma da Aorta Abdominal/cirurgia , Gentamicinas/farmacologia , Virilha/cirurgia , Infecção da Ferida Cirúrgica , Idoso , Idoso de 80 Anos ou mais , Antibioticoprofilaxia/métodos , Aneurisma da Aorta Abdominal/tratamento farmacológico , Colágeno/farmacologia , Procedimentos Endovasculares/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecção da Ferida Cirúrgica/tratamento farmacológico
17.
Molecules ; 25(4)2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059436

RESUMO

Oral administration of bovine collagen peptide (CP) combined with calcium citrate (CC) has been found to inhibit bone loss in ovariectomized rats. However, the protective effects of CP and CP-CC against bone loss have not been investigated in a tail-suspension simulated microgravity (SMG) rat model. Adult Sprague-Dawley rats (n = 40) were randomly divided into five groups (n = 8): a control group with normal gravity, a SMG control group, and three SMG groups that underwent once-daily gastric gavage with CP (750 mg/kg body weight), CC (75 mg/kg body weight) or CP-CC (750 and 75 mg/kg body weight, respectively) for 28 days. After sacrifice, the femurs were analyzed by dual-energy X-ray absorptiometry, three-point bending mechanical tests, microcomputed tomography, and serum bone metabolic markers. Neither CP nor CP-CC treatment significantly inhibited bone loss in SMG rats, as assessed by dual-energy X-ray absorptiometry and three-point bending mechanical tests. However, both CP and CP-CC treatment were associated with partial prevention of the hind limb unloading-induced deterioration of bone microarchitecture, as demonstrated by improvements in trabecular number and trabecular separation. CP-CC treatment increased serum osteocalcin levels. Dietary supplementation with CP or CP-CC may represent an adjunct strategy to reduce the risk of fracture in astronauts.


Assuntos
Doenças Ósseas Metabólicas/tratamento farmacológico , Citrato de Cálcio/farmacologia , Colágeno/farmacologia , Peptídeos/farmacologia , Animais , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/diagnóstico por imagem , Doenças Ósseas Metabólicas/metabolismo , Doenças Ósseas Metabólicas/patologia , Bovinos , Colágeno/química , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Fêmur/patologia , Elevação dos Membros Posteriores/métodos , Humanos , Ovariectomia , Peptídeos/química , Ratos , Ratos Sprague-Dawley , Cauda/diagnóstico por imagem , Cauda/efeitos dos fármacos , Cauda/fisiopatologia , Microtomografia por Raio-X
18.
J Med Food ; 23(2): 147-152, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32017646

RESUMO

The purpose of this randomized, placebo-controlled, triple-blind trial on 60 healthy female volunteers was to assess the cosmetic effects on skin quality of a food supplement containing special collagen peptides together with acerola extract, vitamin C, vitamin E, biotin, and zinc after an intake of 12 weeks (Elasten®, QUIRIS Healthcare, Germany). To reduce assessment bias maximally and increase the accuracy and objectivity of the outcomes, the trial design was triple blinded in a manner that neither the subjects nor the person administering the products nor the person who assessed the primary outcomes knew which subjects had received the test product and which had received the placebo. The expert grader assessing the confocal laser scanning microscopy images was additionally blinded regarding the time when the image was taken (on days 1 or 85). The objective, blinded, and validated image analyses using confocal laser scanning microscopy showed a significant improvement of the collagen structure of facial skin (primary endpoint) after intake of the test product, while no improvements were found after intake of the placebo. The proven positive nutritional effect on the collagen structure was fully consistent with positive subjective evaluations of relevant skin parameters such as elasticity, crinkliness/wrinkliness, and evenness in different body areas such as face, hands, décolleté, neck, backside, legs, and belly, all serving as secondary endpoints. The test product was found to be safe and very well tolerated. A cosmetically relevant improvement of the facial skin was demonstrated after administration of the collagen supplement.


Assuntos
Colágeno/farmacologia , Suplementos Nutricionais , Envelhecimento da Pele/efeitos dos fármacos , Pele/efeitos dos fármacos , Vitaminas/farmacologia , Método Duplo-Cego , Feminino , Humanos , Microscopia Confocal , Pessoa de Meia-Idade
19.
Sci Rep ; 10(1): 2576, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054865

RESUMO

Traumatic injury to the spinal cord causes permanent loss of function and major personal, social, and economic problems. Cell-based delivery strategies is a promising approach for treating spinal cord injury (SCI). However, the inhospitable microenvironment in the injured spinal cord results in poor cell survival and uncontrolled differentiation of the transplanted stem cells. The combination of a scaffold with cells has been developed with a tendency for achieving greater survival and integration with the host tissue. We investigated the effect of Matrigel combined with neural stem cells (NSCs) in vitro and in vivo. We compared the effect of different types of scaffold on the survival and differentiation of brain-derived NSCs in an in vitro culture. Subsequently, NSCs were transplanted subcutaneously into nude mice to detect graft survival and differentiation in vivo. Finally, phosphate-buffered saline (PBS), Matrigel alone, or Matrigel seeded with NSCs was injected into 48 subacute, clinically relevant rat models of SCI (16 rats per group). Matrigel supported cell survival and differentiation efficiently in vitro and in vivo. SCI rats transplanted with NSCs in Matrigel showed improved behavioral recovery and neuronal and reactive astrocyte marker expression levels compared to PBS- or Matrigel-transplanted rats. Functional repair and neuronal and reactive astrocyte marker expression was slightly improved in the Matrigel-alone group relative to the PBS group, but not statistically significantly. These data suggest that Matrigel is a promising scaffold material for cell transplantation to the injured spinal cord.


Assuntos
Células-Tronco Neurais/transplante , Neurogênese/efeitos dos fármacos , Neurônios/metabolismo , Traumatismos da Medula Espinal/terapia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colágeno/farmacologia , Modelos Animais de Doenças , Combinação de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Laminina/farmacologia , Células-Tronco Neurais/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Proteoglicanas/farmacologia , Ratos , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/fisiopatologia , Tecidos Suporte
20.
Int J Mol Sci ; 21(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906476

RESUMO

Bioactive collagen/chitosan complexes were prepared by an ion crosslinking method using fish skin collagen and chitosan solution as raw materials. Scanning electron microscopy observation confirmed that the collagen/chitosan complexes were of a uniform spherical shape and uniform particle size. The complexes were stable at different pH values for a certain period of time through swelling experiments. Differential scanning calorimetry (DSC) showed the collagen/ chitosan complexes were more stable than collagen. X-ray diffraction (XRD) showed that the complexes had a strong crystal structure, and Fourier transform infrared spectroscopy (FTIR) data revealed the changes in the secondary structure of the protein due to chitosan and TPP crosslinking. The content of malondialdehyde (MDA) in the complex treatment group was considerably lower, but the content of SOD was significantly higher than that of the collagen group or chitosan group. In addition, the collagen/chitosan complexes could considerably reduce melanin content, inhibit tyrosinase activity, and down-regulate tyrosinase mRNA expression. In conclusion, the collagen/chitosan complexes were potential oral protein preparation for antioxidant enhancement and inhibiting melanin synthesis.


Assuntos
Antioxidantes/farmacologia , Quitosana/química , Colágeno/química , Colágeno/farmacologia , Melaninas/biossíntese , Monofenol Mono-Oxigenase/antagonistas & inibidores , Animais , Varredura Diferencial de Calorimetria , Quitosana/farmacologia , Colágeno/ultraestrutura , Feminino , Concentração de Íons de Hidrogênio , Masculino , Malondialdeído/análise , Malondialdeído/metabolismo , Melaninas/análise , Melaninas/metabolismo , Melanoma Experimental , Camundongos , Microscopia Eletrônica de Varredura , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Tamanho da Partícula , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier , Superóxido Dismutase/análise , Superóxido Dismutase/metabolismo , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...