Fibrin biopolymer as scaffold candidate to treat bone defects in rats

Bone tissue repair remains a challenge in tissue engineering. Currently, new materials are being applied and often integrated with live cells and biological scaffolds. The fibrin biopolymer (FBP) proposed in this study has hemostatic, sealant, adhesive, scaffolding and drug-delivery properties. The regenerative potential of an association of FBP, biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSCs) was evaluated in defects of rat femurs. Methods: Adult male Wistar rats were submitted to a 5-mm defect in the femur. This was filled with the following materials and/or associations: BPC; FBP and BCP; FBP and MSCs; and BCP, FBP and MSCs. Bone defect without filling was defined as the control group. Thirty and sixty days after the procedure, animals were euthanatized and subjected to computed tomography, scanning electron microscopy and qualitative and quantitative histological analysis. Results: It was shown that FBP is a suitable scaffold for bone defects due to the formation of a stable clot that facilitates the handling and optimizes the surgical procedures, allowing also cell adhesion and proliferation. The association between the materials was biocompatible. Progressive deposition of bone matrix was higher in the group treated with FBP and MSCs. Differentiation of mesenchymal stem cells into osteogenic lineage was not necessary to stimulate bone formation. Conclusions: FBP proved to be an excellent scaffold candidate for bone repair therapies due to application ease and biocompatibility with synthetic calcium-based materials. The satisfactory results obtained by the association of FBP with MSCs may provide a more effective and less costly new approach for bone tissue engineering.(AU)

Fibrin biopolymer as scaffold candidate to treat bone defects in rats

Background:Bone tissue repair remains a challenge in tissue engineering. Currently, new materials are being applied and often integrated with live cells and biological scaffolds. The fibrin biopolymer (FBP) proposed in this study has hemostatic, sealant, adhesive, scaffolding and drug-delivery properties. The regenerative potential of an association of FBP, biphasic calcium phosphate (BCP) and mesenchymal stem cells (MSCs) was evaluated in defects of rat femurs.Methods:Adult male Wistar rats were submitted to a 5-mm defect in the femur. This was filled with the following materials and/or associations: BPC; FBP and BCP; FBP and MSCs; and BCP, FBP and MSCs. Bone defect without filling was defined as the control group. Thirty and sixty days after the procedure, animals were euthanatized and subjected to computed tomography, scanning electron microscopy and qualitative and quantitative histological analysis.Results:It was shown that FBP is a suitable scaffold for bone defects due to the formation of a stable clot that facilitates the handling and optimizes the surgical procedures, allowing also cell adhesion and proliferation. The association between the materials was biocompatible. Progressive deposition of bone matrix was higher in the group treated with FBP and MSCs. Differentiation of mesenchymal stem cells into osteogenic lineage was not necessary to stimulate bone formation.Conclusions:FBP proved to be an excellent scaffold candidate for bone repair therapies due to application ease and biocompatibility with synthetic calcium-based materials. The satisfactory results obtained by the association of FBP with MSCs may provide a more effective and less costly new approach for bone tissue engineering.(AU)

Collagen quantification in rabbit dermal wounds treated with heterologous platelet-rich plasma gel / Quantificação de colágenoem feridas dérmicas de coelhos tratados com plasma rico em plaquetas heterólogo gel

Platelet-rich plasma (PRP) has been extensively studied as a biomaterial for wound treatment, and the heterologous PRP is usefulin the event that obtaining the patients own blood is impossible. This study aimed to evaluate and compare wound healing in rabbits and quantify the collagen in experimentally induced wounds in a control group and in a group treated with heterologous PRP gel. We hypothesize that this gelis capable of promoting proper healing with no adverse reactions, increased collagen content. The clinical aspects of coloring, edema, hyperemia, exudation, crust, granulation, pain sensitivity, and retraction index of the wounds were measuredon days 7, 14, and 17 after the injury. Collagen quantification by Picrosirius staining and evaluation under polarized light was performed on the 17th day. Crust was present in both groups at all evaluated time points, with the absence of other clinical signs. The wound contraction rate and collagen quantity did not differ between groups. In conclusion, the suggested hypothesis was partially confirmed; the heterologous PRP gel was unable to increase the amount of collagen and accelerate the wound healing process, however, wound healing was efficient and similar in both groups and there was no local adverse reaction. Thus, despite the scarcity of studies in the literature, the heterologous PRP gel is an effective alternative treatment for wounds in the absence of other sources of PRP.(AU)

O plasma rico em plaquetas (PRP) tem sido amplamente estudado como um biomaterial para o tratamento de feridas, sendo o produto de fonte heteróloga indicado na impossibilidade de obtenção do sangue do próprio paciente. O presente estudo teve como objetivo, avaliar e comparar a cicatrização em coelhos, e quantificar o colágeno de feridas experimentalmente induzidas, denominadas controle e tratadas, com PRP heterólogo gel. A hipótese é que este produto seja capaz de promover cicatrização adequada sem reações adversas, e promova aumento do colágeno. Os aspectos clínicos cor, edema, hiperemia, exsudato, crosta, granulação, sensibilidade a dor e índice de retração das feridas foram avaliados nos dias 7, 14 e 17 após a lesão. A quantificação do colágeno, através da coloração com Picrosirius e avaliação sob luz polarizada, foi realizada no 17º dia. Houve presença de crosta nos dois grupos em todos os momentos avaliados, com ausência dos demais sinais clínicos. O percentual de contração da lesão e quantidade de colágeno não diferiu entre os grupos. Concluiu-se que a hipótese sugerida foi comprovada em partes, ou seja, o PRP heterólogo gel não foi capaz de aumentar a quantidade de colágeno e acelerar o processo de cicatrização tecidual, no entanto, a cicatrização foi eficiente e semelhante entre os dois grupos e não houve nenhum tipo de reação adversa local. Desta forma, apesar da escassez de estudos encontrados na literatura, o PRP heterólogo gel é uma alternativa de tratamento de feridas, na impossibilidade de uso de outras fontes de PRP.(AU)

Avaliação da fosfatase alcalina óssea e hepática em gatos com tirotoxicose induzida / Evaluation of bone and liver alkaline phosphatase in cats with induced thyrotoxicosis

A tirotoxicose é caracterizada pelas excessivas concentrações séricas dos hormônios tiroidianos, podendo desencadear graves alterações no metabolismo ósseo, sendo a elevação da fosfatase alcalina total uma alteração laboratorial freqüentemente observada no hipertiroidismo felino. O aumento global dos níveis séricos de fosfatase alcalina pode ser decorrente de diferentes isoenzimas e, no caso do hipertiroidismo em humanos, as isoenzimas de origem óssea e hepática apresentam-se comumente elevadas. A partir da avaliação da bioquímica sérica de oito gatos com tirotoxicose induzida e elevação da fosfatase alcalina associada, o presente trabalho demonstra um aumento significativamente maior dos níveis séricos da fosfatase alcalina de origem óssea quando comparado com a isoenzima de origem hepática. Conclui-se que as alterações no metabolismo ósseo foram as principais responsáveis pelo aumento da fosfatase alcalina nos gatos com tirotoxicose induzida.(AU)

Thyrotoxicosis, characterized by excessive serum levels of thyroidhormones, can cause serious effects in bone metabolism, elevating the total alkaline phosphatase, which is a frequent laboratorial alteration observed in feline hyperthyroidism. A rise in total serum levels of alkaline phosphatase can be caused by different isoenzymes, and in human hyperthyroidism, bone and hepatic isoenzymes are commonly increased. After serum biochemical evaluation of eight cats with induced thyrotoxicosis and associated elevation of alkaline phosphatase, the present paper shows a significant elevation of bone isoenzyme serum levels when compared with hepatic isoenzyme. It was possible to conclude that bone metabolism alterations were the main responsible for the increase of serum alkaline phosphatase in cats with induced thyrotoxicosis.(AU)

Collagen quantification in rabbit dermal wounds treated with heterologous platelet-rich plasma gel / Quantificação de colágenoem feridas dérmicas de coelhos tratados com plasma rico em plaquetas heterólogo gel

Platelet-rich plasma (PRP) has been extensively studied as a biomaterial for wound treatment, and the heterologous PRP is usefulin the event that obtaining the patient’s own blood is impossible. This study aimed to evaluate and compare wound healing in rabbits and quantify the collagen in experimentally induced wounds in a control group and in a group treated with heterologous PRP gel. We hypothesize that this gelis capable of promoting proper healing with no adverse reactions, increased collagen content. The clinical aspects of coloring, edema, hyperemia, exudation, crust, granulation, pain sensitivity, and retraction index of the wounds were measuredon days 7, 14, and 17 after the injury. Collagen quantification by Picrosirius staining and evaluation under polarized light was performed on the 17th day. Crust was present in both groups at all evaluated time points, with the absence of other clinical signs. The wound contraction rate and collagen quantity did not differ between groups. In conclusion, the suggested hypothesis was partially confirmed; the heterologous PRP gel was unable to increase the amount of collagen and accelerate the wound healing process, however, wound healing was efficient and similar in both groups and there was no local adverse reaction. Thus, despite the scarcity of studies in the literature, the heterologous PRP gel is an effective alternative treatment for wounds in the absence of other sources of PRP.

O plasma rico em plaquetas (PRP) tem sido amplamente estudado como um biomaterial para o tratamento de feridas, sendo o produto de fonte heteróloga indicado na impossibilidade de obtenção do sangue do próprio paciente. O presente estudo teve como objetivo, avaliar e comparar a cicatrização em coelhos, e quantificar o colágeno de feridas experimentalmente induzidas, denominadas controle e tratadas, com PRP heterólogo gel. A hipótese é que este produto seja capaz de promover cicatrização adequada sem reações adversas, e promova aumento do colágeno. Os aspectos clínicos cor, edema, hiperemia, exsudato, crosta, granulação, sensibilidade a dor e índice de retração das feridas foram avaliados nos dias 7, 14 e 17 após a lesão. A quantificação do colágeno, através da coloração com Picrosirius e avaliação sob luz polarizada, foi realizada no 17º dia. Houve presença de crosta nos dois grupos em todos os momentos avaliados, com ausência dos demais sinais clínicos. O percentual de contração da lesão e quantidade de colágeno não diferiu entre os grupos. Concluiu-se que a hipótese sugerida foi comprovada em partes, ou seja, o PRP heterólogo gel não foi capaz de aumentar a quantidade de colágeno e acelerar o processo de cicatrização tecidual, no entanto, a cicatrização foi eficiente e semelhante entre os dois grupos e não houve nenhum tipo de reação adversa local. Desta forma, apesar da escassez de estudos encontrados na literatura, o PRP heterólogo gel é uma alternativa de tratamento de feridas, na impossibilidade de uso de outras fontes de PRP.

Collagen quantification in rabbit dermal wounds treated with heterologous platelet-rich plasma gel / Quantificação de colágenoem feridas dérmicas de coelhos tratados com plasma rico em plaquetas heterólogo gel

Platelet-rich plasma (PRP) has been extensively studied as a biomaterial for wound treatment, and the heterologous PRP is usefulin the event that obtaining the patients own blood is impossible. This study aimed to evaluate and compare wound healing in rabbits and quantify the collagen in experimentally induced wounds in a control group and in a group treated with heterologous PRP gel. We hypothesize that this gelis capable of promoting proper healing with no adverse reactions, increased collagen content. The clinical aspects of coloring, edema, hyperemia, exudation, crust, granulation, pain sensitivity, and retraction index of the wounds were measuredon days 7, 14, and 17 after the injury. Collagen quantification by Picrosirius staining and evaluation under polarized light was performed on the 17th day. Crust was present in both groups at all evaluated time points, with the absence of other clinical signs. The wound contraction rate and collagen quantity did not differ between groups. In conclusion, the suggested hypothesis was partially confirmed; the heterologous PRP gel was unable to increase the amount of collagen and accelerate the wound healing process, however, wound healing was efficient and similar in both groups and there was no local adverse reaction. Thus, despite the scarcity of studies in the literature, the heterologous PRP gel is an effective alternative treatm

O plasma rico em plaquetas (PRP) tem sido amplamente estudado como um biomaterial para o tratamento de feridas, sendo o produto de fonte heteróloga indicado na impossibilidade de obtenção do sangue do próprio paciente. O presente estudo teve como objetivo, avaliar e comparar a cicatrização em coelhos, e quantificar o colágeno de feridas experimentalmente induzidas, denominadas controle e tratadas, com PRP heterólogo gel. A hipótese é que este produto seja capaz de promover cicatrização adequada sem reações adversas, e promova aumento do colágeno. Os aspectos clínicos cor, edema, hiperemia, exsudato, crosta, granulação, sensibilidade a dor e índice de retração das feridas foram avaliados nos dias 7, 14 e 17 após a lesão. A quantificação do colágeno, através da coloração com Picrosirius e avaliação sob luz polarizada, foi realizada no 17º dia. Houve presença de crosta nos dois grupos em todos os momentos avaliados, com ausência dos demais sinais clínicos. O percentual de contração da lesão e quantidade de colágeno não diferiu entre os grupos. Concluiu-se que a hipótese sugerida foi comprovada em partes, ou seja, o PRP heterólogo gel não foi capaz de aumentar a quantidade de colágeno e acelerar o processo de cicatrização tecidual, no entanto, a cicatrização foi eficiente e semelhante entre os dois grupos e não houve nenhum tipo de reação adversa local. Desta forma, apesar da escas