Liquid and Gel Platelet Rich Plasma as Skin Healing Adjuvant

Abstract

Background: In recent decades, many researches have been conducted on processes involved in tissue repairing, mainly in the development of resources and technology designed to improve the wound healing progress. Platelet rich plasma (PRP) derived from autologous blood is defined as a plasma volume with platelet concentration higher than physiological level. It is an autogenous and low cost source of growth factors, which are essential for tissue regeneration due to their angiogenic, mitogenic, and chemotactic properties. The aim of this study was evaluate two forms of PRP- liquid and gel - regarding their capacity to influence quality and repair time of standardized skin injuries.Materials, Methods & Results: New Zealand healthy rabbits were distributed in three groups (n = 6): control group (CG), liquid platelet rich plasma group (LIQPRP), and gel platelet rich plasma group (GELPRP). Acute skin lesions were inducted in two areas approximately 2 cm close to scapular edge and depth including epidermis, dermis, and hypodermis to external muscular fascia. Animals received treatment according to each group. Injuries were measured with digital pachymeter in two directions: longer length (l) and longer width (w), every two days. Areas and healing rates were calculated. Microscopic analysis samples were collected on days seven and 14 and evaluated through hematoxylin and eosin staining (HE) for global tissue examination, and through Masson’s trichrome (MT) to collagen fibers present within the interstice. These analyzes considered: angiogenesis, inflammation infiltrated and collagen fibers quantity. Immunohistochemistry with anti-Ki-67 antibody was utilized for proliferative profile assessment. Kruskal-Wallis’ non-parametric tests of independent samples was performed for comparison of values obtained through platelet count, referring to evaluation of platelet increase on treatments. Scar contraction rate (CR) was evaluated through Shapiro-Wilk’s normality test, and then submitted to mixed models test. Results obtained by histopathological and immunohistochemistry were also evaluated by Shapiro-Wilk’s normality test (for all tests a 5% level of significance was considered). Platelet concentration achieved with liquid PRP was 8.64 and gel PRP reached 5.62 times higher than physiological values. Platelet increase mean for both groups was 7.95. No statistical significance was observed between groups. No side-effects or adverse reactions related to PRP usage were observed while study was conducted.Discussion: In the present study, there was a need to raise platelet poor plasma volume in order to obtain autogenous thrombin required for gel PRP. After this modification, a stable and reasonable platelet concentration gel was produced. However, this form of PRP application requires more time for sample preparation, increasing the production cost. Furthermore, injection of liquid PRP directly in the wound site activates platelets by generated substances due to needle perforation, and mainly due to tissue trauma generated at the lesion site. Relating to the therapies administered, gel PRP was considered more manageable, since 3D structure could easily adapt to wound site after simply deposition of it. Liquid PRP was administered with needle and syringe, which required the surgeon to be more careful and perform a slow injection in order to avoid any spill and loss of material. Furthermore, histopathological analysis did not point any clot traces formed by gel PRP dehydration, although it is not possible to ensure that the clot was eliminated, reabsorbed, or even removed by the animal. By this protocol, a stable and reasonable platelet concentration gel was produced. Further studies are encouraged as well as employment of alternative diagnostic tools, in order to better understand found results.

Desenvolvimento de um dispositivo para obter plasma rico em plaquetas (PRP)

“…Regarding the centrifugation method, it can be single or double centrifugation. The present study opted for the double centrifugation protocol, recommended by Landsberg et al 20 and by Garcez et al, 21 having been shown to be effective, since an increase of at least 100% in the number of platelets was observed. There were also increases in the amount of platelets close to 200%, making it possible to obtain even more favorable results.…”

“…Em relação ao método de centrifugação, pode ser centrifugação única ou dupla. O presente estudo optou pelo protocolo de centrifugação dupla, recomendado por Landesberg et al 20 e Garcez et al, 21 tendo se mostrado eficaz, com aumento de ao menos 100% no número de plaquetas. Também houve aumento na quantidade de plaquetas próximo a 200%, possibilitando a obtenção de resultados ainda mais favoráveis.…”

Is PRP Effective in Reducing the Scar Width of Primary Cleft Lip Repair? A Randomized Controlled Clinical Study

“…Finally, the sample showed a platelet pellet and plasma. The platelet pellet was collected with 1 mL of plasma, with the counting of various cells, and transferred into an insulin syringe (Garcez et al, 2016; Table 1). Following muscle closure, approximately 0.25 mL of PRP was injected on each side along the suture line of the muscle layer, and another 0.25 mL of PRP was injected on each side along the suture line of the dermis layer.…”

Uso de plasma rico em plaquetas para tratamento de tendinite na medicina equina

“…O PRP tem sido descrito como alternativa simples e barata para o tratamento de diversas lesões, promovendo liberação de fatores pró-cicatriciais (Boswell et al, 2012;Wasterlain et al, 2016) e estimulando a expressão e transcrição gênica de substâncias que auxiliam no processo de reparação tecidual (Romero et al, 2017) e assim, seu uso em diferentes espécies tem obtido sucesso na cicatrização de lesões de pele (Garcez et al, 2016), cartilagem (Coskun et al, 2019;Yamada et al, 2016) e tendões (Bazzano et al, 2013;Maia et al, 2009). Diante disso, o objetivo desta revisão foi levantar dados na literatura sobre a obtenção, utilização e efeitos do PRP no tratamento de lesões tendíneas na espécie equina.…”