Navegando por Palavras-chave "platelet-rich plasma"

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    Interface between breast cancer cells and the tumor microenvironment using platelet-rich plasma to promote tumor angiogenesis - influence of platelets and fibrin bundles on the behavior of breast tumor cells
    (Impact Journals Llc, 2017) Andrade, Sheila Siqueira [UNIFESP]; Sumikawa, Joana Tomomi [UNIFESP]; Castro, Eloisa Dognani [UNIFESP]; Batista, Fabricio Pereira [UNIFESP]; Paredes-Gamero, Edgar [UNIFESP]; Oliveira, Lilian Carolina; Guerra, Izabel Monasterio [UNIFESP]; Peres, Giovani Bravin [UNIFESP]; Cavalheiro, Renan Pelluzzi [UNIFESP]; Juliano, Luiz; Nazario, Afonso Pinto [UNIFESP]; Facina, Gil [UNIFESP]; Tsai, Siu Mui; Vilela Oliva, Maria Luiza [UNIFESP]; Batista Castello Girao, Manoel Joao [UNIFESP]
    Cancer progression is associated with an evolving tissue interface of direct epithelial-tumor microenvironment interactions. In biopsies of human breast tumors, extensive alterations in molecular pathways are correlated with cancer staging on both sides of the tumor-stroma interface. These interactions provide a pivotal paracrine signaling to induce malignant phenotype transition, the epithelial-mesenchymal transition (EMT). We explored how the direct contact between platelets-fibrin bundles primes metastasis using platelet-rich plasma (PRP) as a source of growth factors and mimics the provisional fibrin matrix between actively growing breast cancer cells and the tumor stroma. We have demonstrated PRP functions, modulating cell proliferation that is tumor-subtype and cancer cell-type-specific. Epithelial and stromal primary cells were prepared from breast cancer biopsies from 21 women with different cancer subtypes. Cells supplemented with PRP were immunoblotted with anti-phospho and total Src-Tyr-416, FAK-Try-925, E-cadherin, N-cadherin, TGF-beta, Smad2, and Snail monoclonal antibodies. Breast tumor cells from luminal B and HER2 subtypes showed the most malignant profiles and the expression of thrombin and other classes of proteases at levels that were detectable through FRET peptide libraries. The angiogenesis process was investigated in the interface obtained between platelet-fibrin-breast tumor cells co-cultured with HUVEC cells. Luminal B and HER2 cells showed robust endothelial cell capillary-like tubes ex vivo. The studied interface contributes to the attachment of endothelial cells, provides a source of growth factors, and is a solid substrate. Thus, replacement of FBS supplementation with PRP supplementation represents an efficient and simple approach for mimicking the real multifactorial tumor microenvironment.
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    Nerve Regeneration: Is There an Alternative to Nervous Graft?
    (Thieme Medical Publ Inc, 2014-11-01) Sabongi, Rodrigo Guerra [UNIFESP]; Lucas Martins de Rizzo, Luiz Augusto [UNIFESP]; Fernandes, Marcela [UNIFESP]; Valente, Sandra Gomes [UNIFESP]; Gomes dos Santos, Joao Baptista [UNIFESP]; Faloppa, Flavio [UNIFESP]; Leite, Vilnei Mattioli [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Background in nerve injury with nervous gap, no restitution method was found better than the autograft, however, it has the disadvantage of damaging a normal nerve to be used as a graft. Platelet-rich plasma (PRP) is a possible filler material for vein grafts used as conduits for nerve regeneration, preventing its collapse, and providing growth factors and osteoconductive proteins.Methods Isogenic rats were randomly divided into three groups. They received nerve autografts (GRF), PRP-containing vein grafts or a sham operation. Outcomes were evaluated by the sciatic functional index (SFI), morphometric, and morphologic analyses of the nerve distal to the lesion, and the number of spinal cord motoneurons positive for retrograde Fluoro-Gold (Santa Cruz Biotechnology, Inc., Dallas, TX) tracer.Results the PRP and GRF groups had lower SFI values than the control animals throughout the postoperative period. the SFI was significantly higher in the PRP group than the GRF group at 90 days postoperatively (p = 0.011). Fiber diameter and number of motoneurons were significantly decreased in both the PRP and GRF groups, as compared with the control.Conclusion PRP within a vein conduit may be an effective alternative or adjuvant to GRF, the current preferred treatment for nerve injury with a nerve gap, and further investigations are required to fully define the role of PRP in nerve regeneration.
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    Platelet-Rich Plasma in a Murine Model: Leukocytes, Growth Factors, Flt-1, and Muscle Healing
    (Sage Publications Inc, 2016) Andrade Denapoli, Priscila Martins [UNIFESP]; Stilhano, Roberta Sessa [UNIFESP]; McNeill Ingham, Sheila Jean [UNIFESP]; Han, Sang Won [UNIFESP]; Abdalla, Rene Jorge [UNIFESP]
    Background: It is well known that platelet-rich plasma (PRP) preparations are not the same and that not all preparations include white blood cells, but the part that leukocytes play on the healing role of PRP is still unknown. Purpose: The primary aim of this study was to evaluate the influence of leukocytes in different PRP preparations with a special emphasis on growth factor concentrations. The secondary aim was to evaluate the influence of PRP on muscle healing. Study Design: Controlled laboratory study. Methods: Two PRP preparation procedures were evaluated. Blood fractions were stained with Rapid Panoptic, and growth factors (transforming growth factor beta 1 [TGF-1], vascular endothelial growth factor [VEGF], insulin-like growth factor [IGF], epidermal growth factor [EGF], hepatocyte growth factor [HGF], and platelet-derived growth factor [PDGF]) were quantified by enzyme-linked immunosorbent assay. Western blotting analysis was performed for Fms-related tyrosine kinase 1 (Flt-1). A muscle contusion injury was created and treated with PRP at different time points. Results: Leukocytes were the main source of VEGF, and all other growth factors measured had a higher concentration in the preparations that included the buffy coat and consequently had a higher concentration of white blood cells. Flt-1 was also found in platelet-poor plasma (PPP). There were higher concentrations of PDGF and HGF in the preparations that encompassed the buffy coat. A PRP injection 7 days after the injury provided significantly increased exercise performance and decreased the fibrotic area when compared with other PRP-treated groups. Conclusion: VEGF is only present in PRPs buffy coat, while Flt-1 is present in PPP. A PRP injection 7 days after an injury resulted in improved exercise performance. Clinical Relevance: The presence of Flt-1 in PRP provides yet another explanation for results described in the literature after a PRP injection. This information is relevant for selecting the best PRP for each type of injury.