Resultado da pesquisa (4)
Termo utilizado na pesquisa growth factors
#1 - Comparison of the effects of platelet-rich fibrin and platelet-rich plasma on experimental tendon injury in rabbits
Abstract in English:
This study aimed to compare the early-phase histopathological and immunohistochemical effects of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) following their application in the inflammatory phase of experimentally induced calcaneal tendon injuries in a rabbit model. A complete calcaneal tenotomy was performed and repaired using the modified Kessler technique. In the PRP group, 0.5–1 ml of non-activated liquid PRP was injected into the paratenon. In the PRF group, a PRF membrane was wrapped around the tenotomy site. The Control group received sutures only. On the 14th postoperative day, tendon tissue samples were collected for analysis. Healing was assessed via histopathology (HE, Masson’s trichrome) and immunohistochemistry for key growth factors (TGF-β, VEGF, FGF-β) and inflammatory markers (iNOS, nitrotyrosine). Histopathological evaluation revealed that both PRP and PRF groups exhibited superior healing compared to the Control group, characterized by reduced inflammatory cell infiltration, less edema, and a more organized, parallel arrangement of newly synthesized collagen fibers. Compared to controls, both treatment groups showed significantly increased expression of the pro-regenerative FGF-β and decreased expression of TGF-β and VEGF. Furthermore, levels of iNOS and nitrotyrosine were markedly lower in the PRP and PRF groups. Both PRP and PRF demonstrated comparable and significant efficacy in enhancing the quality of early tendon repair. Their therapeutic effect appears to be multifactorial, created by a pro-regenerative and anti-inflammatory microenvironment that favorably modulates growth factor expression and reduces inflammatory tissue damage. These findings support the use of both preparations as effective strategies to promote healing in acute tendon injuries.
Abstract in Portuguese:
Este estudo teve como objetivo comparar os efeitos histopatológicos e imuno-histoquímicos de fase inicial do plasma rico em plaquetas (PRP) e fibrina rica em plaquetas (PRF) após a sua aplicação na fase inflamatória de lesões do tendão calcâneo, induzida experimentalmente em um coelho. Uma tenotomia completa do calcâneo foi realizada e reparada através da técnica de Kessler modificada. No grupo PRP, foram injetados 0,5–1 ml de PRP líquido não ativado no espaço do paratendão. No grupo PRF, uma membrana de PRF foi enrolada em torno do local da tenotomia. O Grupo controle recebeu apenas suturas. No 14º dia pós-operatório, os tecidos tendinosos foram recolhidos para análise. A cicatrização foi avaliada por histopatologia (HE, tricrômico de Masson) e imunohistoquímica para fatores de crescimento chave (TGF-β, VEGF, FGF-β) e marcadores inflamatórios (iNOS, nitrotirosina). A avaliação histopatológica revelou que ambos os grupos, PRP e PRF, apresentaram uma cicatrização superior em comparação com o Grupo controle, caracterizada por uma menor infiltração de células inflamatórias, menos edema e um arranjo paralelo mais organizado das fibras de colágeno recém-sintetizadas. Em comparação com os controles, ambos os grupos de tratamento apresentaram uma expressão significativamente aumentada do pró-regenerador FGF-β e uma expressão diminuída de TGF-β e VEGF. Além disso, os níveis de iNOS e nitrotirosina foram significativamente mais baixos nos grupos PRP e PRF. Tanto o PRP como o PRF demonstraram uma eficácia comparável e significativa na melhoria da qualidade da reparação precoce do tendão. O seu efeito terapêutico parece ser multifatorial, envolvendo a criação de um microambiente pró-regenerador e anti-inflamatório, modulando favoravelmente a expressão do fator de crescimento e reduzindo os danos inflamatórios nos tecidos. Estes achados corroboram a utilização de ambas as preparações como estratégias eficazes para promover a cicatrização em lesões agudas do tendão.
#2 - Evaluation of platelet-rich plasma gel as an angiogenesis-inducing agent in canine advancement skin flaps
Abstract in English:
This work aimed to evaluate the effect of platelet-rich plasma (PRP) on advancement skin flaps in dogs regarding improvement of vascularization, with focus on increasing its viable area, since there are reports that it is a potential angiogenesis stimulator. The experimental group was composed of eight adult bitches, in which two advancement skin flaps were made in the ventral abdominal region. No product was applied in the control flap (CF), while PRP was used in the contralateral flap, called treated flap (TF). The areas were clinically evaluated every two days until the 7th postoperative day regarding skin color and presence of necrosis. At 10 days, both flaps were removed and submitted to histological examination and blood vessel morphometry. The vessels counted in each group were statistically analyzed by the F-test at 1% probability. Results showed no significant difference in macroscopic changes in the wound, or CF and TF vascularization, thus suggesting that PRP gel did not improve advancement skin flap angiogenesis in bitches under the experimental conditions in which this research was developed.
Abstract in Portuguese:
Objetivou-se com o presente artigo avaliar a ação angiogênica do gel de plasma rico em plaquetas (PRP) em flapes cutâneos de avanço em animais da espécie canina, visando aumentar a viabilidade da pele após o procedimento, uma vez que existem relatos de que o produto é um potente estimulador da angiogênese. O grupo experimental foi composto por oito cadelas adultas, onde foram confeccionados dois flapes de avanço (de padrão subdérmico) na região abdominal ventral. Em um dos flapes, considerado controle (FC) não foi aplicado nenhum produto, enquanto que no flape contralateral, denominado tratado (FT), foi usado o gel de PRP. As áreas foram macroscopicamente avaliadas a cada dois dias até o 7º dia de pós-operatório em relação à coloração da pele e presença de área de necrose, e com 10 dias ambos os flapes foram coletados por biópsia e submetidos ao exame histológico e morfometria dos vasos sanguíneos. Os vasos contados em cada grupo foram estatisticamente analisados pelo teste de F ao nível de 1% de probabilidades. Os resultados demonstraram que não houve diferença significativa nas alterações macroscópicas das feridas e na morfometria vascular dos FC e FT, sugerindo dessa maneira que dentro das condições experimentais nas quais a pesquisa foi executada, que o gel de PRP não incrementou a angiogênese de flapes de avanço em cadelas.
#3 - Quantification of growth factors in horse skin treated with platelet-rich plasma, 34(6):599-612
Abstract in English:
ABSTRACT.- Souza M.V., Pinto J.O., Costa M.M., Santos E.C., Garcia S.L.R. & Oliveira L.L. 2014. [Quantification of growth factors in horse skin treated with platelet-rich plasma.] Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas. Pesquisa Veterinária Brasileira 34(6):599-612. Departamento de Veterinária, Universidade Federal de Viçosa, Campus Universitário s/n, Viçosa, MG 36570-000, Brazil. E-mail: msouza@ufv.br
Platelet-rich plasma (PRP) is a product derived from total blood centrifugation, rich in bioactive factors, such as growth factors. Despite largely used in healing processes, there is a controversy whether the therapy is effective in promoting skin healing. The objective of this study was to quantify and compare the concentrations of the factors TGF-β1 and PDGF-BB in PRP, blood plasma and skin, at different phases of the healing process of skin treated or not with PRP. Seven healthy crossbred 16 to 17-year-old geldings (16.14±0.63) were used. Three quadrangular-shaped lesions (6.25cm2) were surgically induced into the right and left gluteal regions of all animals. Twelve hours after induction of the wounds, 0.5mL of the PRP was administered in each of the four edges of the wound in one of the gluteal regions (Treated group = TG) randomly chosen. The contralateral region was used as control (CG). The wounds were submitted to daily cleaning with Milli-Q water, and samples were obtained with a 6mm diameter biopsy Punch. Six skin biopsies were obtained, the first carried out immediately after the production of the wound (T0), and the others 1 (T1), 2 (T2), 7 (T3), and 14 (T4) days after the lesion was induced. The sixth biopsy (T5) was obtained after complete healing of the skin, which occurred at about day 37 (36.85±7.45, CG; 38.85±6.46, TG). EDTA blood samples were also obtained, at all the times mentioned. Quantification of TGF-β1 and PDGF-BB growth factors on the skin, PRP, and blood plasma was carried out by the ELISA technique. Data were statistically analyzed by the t test, Pearson correlation and regression, at a significance level of 5%. No difference was found between the groups in the values of the two growth factors measured on the skin, at the different times. Also, no correlation was found between the amount of growth factors present in the skin and plasma. On the other hand, a positive correlation was observed between PRP and skin in the treated group, for the growth factors TGF-β1 (r=0.31) and PDGF-BB (r=0.38), as well as between both growth factors present in PRP (r=0.81). Considering the growth factor concentrations at T0, the highest skin values (p<0.05) of TGF-β1, in both groups, occurred at T3 and T5. Higher values (p<0.05) of PDGF-BB occurred at T4 (TG) and T5 (CG). No plasma changes occurred at the concentration of these factors in relation to T0, suggesting that PRP does not cause a systemic effect when the procedures adopted in this research are used. Local administration of PRP in the volume studied, 12 h after surgical induction of cutaneous wound gluteal equine does not cause higher concentrations of the growth factors TGF-β1 and PDGF-BB in the plasma and skin during the healing process.
Abstract in Portuguese:
RESUMO.- Souza M.V., Pinto J.O., Costa M.M., Santos E.C., Garcia S.L.R. & Oliveira L.L. 2014. [Quantification of growth factors in horse skin treated with platelet-rich plasma.] Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas. Pesquisa Veterinária Brasileira 34(6):599-612. Departamento de Veterinária, Universidade Federal de Viçosa, Campus Universitário s/n, Viçosa, MG 36570-000, Brazil. E-mail: msouza@ufv.br
O plasma rico em plaquetas (PRP) é um produto derivado da centrifugação do sangue total, sendo rico em fatores bioativos, como os de crescimento. Apesar da ampla utilização em processos cicatriciais, há controvérsia sobre a eficácia da terapia na cicatrização cutânea. O objetivo desse estudo foi quantificar e comparar a concentração dos fatores TGF-β1 e PDGF-BB no PRP, plasma sanguíneo e pele, durante diferentes fases do processo de cicatrização da pele tratada ou não com PRP. Foram utilizados sete equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,14±0,63) anos. Três lesões em formato quadrangular (6,25cm2) foram produzidas cirurgicamente nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das feridas, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas de uma das regiões glúteas (Grupo tratado = GT), escolhida aleatoriamente. A região contralateral foi utilizada como controle (GC). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas mediante biópsias realizadas com Punch de 6mm. Foram obtidas seis biópsias de pele, sendo a primeira realizada logo após a produção da ferida (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a indução da lesão. A sexta biópsia (T5) foi obtida após completo fechamento da pele, que ocorreu aproximadamente aos 37 dias (36,85±7,45, GC; 38,85±6,46, GT). Também foram obtidas amostras de sangue com EDTA em todos os tempos mencionados. A quantificação dos fatores de crescimento TGF-β1 e PDGF-BB na pele, PRP e plasma sanguíneo foi realizada pela técnica ELISA. Os dados foram analisados estatisticamente pelo teste t, correlação de Pearson e regressão, utilizando nível de significância de 5%. Não houve diferença entre os grupos, nos valores dos dois fatores de crescimento mensurados na pele, nos diferentes tempos. Também não houve correlação entre a quantidade dos fatores de crescimento presentes na pele e no plasma. Por outro lado, correlação positiva foi observada entre PRP e pele no grupo tratado, para os fatores de crescimento TGF-β1 (r=0,31) e PDGF-BB (r=0,38), bem como entre ambos os fatores de crescimento presentes no PRP (r=0,81). Considerando as concentrações dos fatores de crescimento no T0, os maiores valores cutâneos (p<0,05) do TGF-β1, em ambos os grupos, ocorreram nos tempos T3 e T5. Valores mais elevados (p<0,05) do PDGF-BB ocorreram no T4 (GT) e T5 (GC). No plasma não houve alteração nas concentrações desses fatores em relação ao T0, o que sugere que o PRP não acarreta efeito sistêmico, quando os procedimentos adotados na presente pesquisa são utilizados. A administração local de PRP no volume estudado, 12 h após indução cirúrgica de ferida cutânea na região glútea de equinos não ocasiona maiores concentrações dos fatores de crescimento TGF-β1 e PDGF-BB no plasma sanguíneo e pele, durante o processo de cicatrização.
#4 - Plasma rico em plaquetas no tratamento de tendinite induzida em eqüinos: avaliação ultra-sonográfica, p.241-245
Abstract in English:
ABSTRACT.- Maia L., Souza M.V., Alves G.E.S., Júnior J.I.R., Oliveira A.C., Silva Y.F.R.S. & Zandim B.M. 2009. [Platelet-rich plasma in the treatment of induced tendinitis in equines: Ultrasonographic evaluation.] Plasma rico em plaquetas no tratamento de tendinite induzida em eqüinos: avaliação ultra-sonográfica. Pesquisa Veterinária Brasileira 29(3):241-245. Setor de Clínica e Cirurgia de Grandes Animais, Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: msouza@ufv.br
The objective of the study was to evaluate the effect of platelet-rich plasma (PRP) in the treatment of induced tendinitis in the superficial digital flexor tendon (SDFT) of horses through ultrasonographic evaluation. Thus, six 8 to15-year-old healthy gelding horses (=12 years) were used. Tendinitis of the SDFT was provoked in both forelimbs via intratendineous administration of 2.5mg of collagenase (2.5mg.mL-1), what was considered as beginning of the experimental phase. Twelve days after induced tendinitis, the horses were submitted to two treatments: (1) in the lesion caused in the right SDFT (treated group, TG), 2.5mL of PRP activated with calcium chloride at 0.0125mol.L-1, at concentrations from 320,000 to 500,000 platelets.µL-1, were administered; (2) in the tendinitis of the left SDFT (control group, CG), 2.5mL of 0.9% saline solution was administered. After 5 days, the animals were submitted to controlled and progressive physical activity during 30 days. Ultrasonographic examinations were carried out before and after tendinitis induction (48 hours after and on experimental days 7, 12, 14, 21 28, 35 and 42), with tendon cross-sectional area (CSA), lesion cross-sectional area (L-CSA), L-CSA percentage, severity and echogenicity of the lesion, as well as collagen fiber alignment being evaluated. The result revealed reduction (P<0.05) in the L-CSA and in the degree of lesion echogenicity in function of time, but with difference (P<0.05) between groups only for L-CSA, with smaller values in TG. The treatment with PRP promotes greater reduction in the area of the lesion measured by ultrasound.
Abstract in Portuguese:
ABSTRACT.- Maia L., Souza M.V., Alves G.E.S., Júnior J.I.R., Oliveira A.C., Silva Y.F.R.S. & Zandim B.M. 2009. [Platelet-rich plasma in the treatment of induced tendinitis in equines: Ultrasonographic evaluation.] Plasma rico em plaquetas no tratamento de tendinite induzida em eqüinos: avaliação ultra-sonográfica. Pesquisa Veterinária Brasileira 29(3):241-245. Setor de Clínica e Cirurgia de Grandes Animais, Departamento de Veterinária, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brazil. E-mail: msouza@ufv.br
The objective of the study was to evaluate the effect of platelet-rich plasma (PRP) in the treatment of induced tendinitis in the superficial digital flexor tendon (SDFT) of horses through ultrasonographic evaluation. Thus, six 8 to15-year-old healthy gelding horses (=12 years) were used. Tendinitis of the SDFT was provoked in both forelimbs via intratendineous administration of 2.5mg of collagenase (2.5mg.mL-1), what was considered as beginning of the experimental phase. Twelve days after induced tendinitis, the horses were submitted to two treatments: (1) in the lesion caused in the right SDFT (treated group, TG), 2.5mL of PRP activated with calcium chloride at 0.0125mol.L-1, at concentrations from 320,000 to 500,000 platelets.µL-1, were administered; (2) in the tendinitis of the left SDFT (control group, CG), 2.5mL of 0.9% saline solution was administered. After 5 days, the animals were submitted to controlled and progressive physical activity during 30 days. Ultrasonographic examinations were carried out before and after tendinitis induction (48 hours after and on experimental days 7, 12, 14, 21 28, 35 and 42), with tendon cross-sectional area (CSA), lesion cross-sectional area (L-CSA), L-CSA percentage, severity and echogenicity of the lesion, as well as collagen fiber alignment being evaluated. The result revealed reduction (P<0.05) in the L-CSA and in the degree of lesion echogenicity in function of time, but with difference (P<0.05) between groups only for L-CSA, with smaller values in TG. The treatment with PRP promotes greater reduction in the area of the lesion measured by ultrasound.
