Applicability of biopolymers implanted in horses

Abstract

Biomaterials are designed to interact with biological systems, and may be synthetic, such as metal, or natural, such as biopolymers. The development of new technologies from renewable sources is being widely used in the different areas of knowledge, due to the great concern with the preservation of the environment. In the area of biotechnology, biopolymers produced from carbohydrates are easily degraded and have potential for biomedical use. In veterinary medicine, interest is seen in the development of long-lasting drug formulations, with alternative biopolymers being feasible to play the role of carrier, as well as their use as scaffolds for bone regeneration, sutures, screws, pins and plaques for orthopedic surgeries. The present study will aim to evaluate the biocompatibility and safety of the subcutaneous implantation of different biopolymers in equine. For this, six horses will be used, mixed-breed, aged between 10 and 18 years and average weight of 423 kg. Four experimental groups will be performed: negative control group, positive control group, and two groups with different proportions of PLA as the predominant material, being PLA 100% and PLA 75%. The animals will undergo a surgical procedure for implantation of the biopolymer in the subcutaneous tissue in the region of the neck board. Evaluations will be performed prior to the procedure, for seven days after implantation, weekly up to eight weeks, and biweekly up to 24 weeks. The serological analysis will consist of determination of the plasma concentration of fibrinogen. The nociceptive response will be evaluated by Von Frey filaments (FVF). Thermographic and ultrasonographic examinations will be performed, and the histopathological analyzes will be done by hematoxylin and eosin and picrosirius staining methods. The experiment will follow the 4 x 1 x 3 factorial design (4 treatments, 1 implant site and 3 evaluation times), following the 3x6 change-over delineation in which the lines will be composed of the periods (3 distinct weeks) and the columns (4 treatments: negative control, positive control, PLA 75, PLA 100) and each sub-plot will be a moment of evaluation. Multiple-effects analyzes of mixed effects will be performed for time-repeated measures and the means will be compared by Tukey's test with significance p <0.05, using the SAS 9.3 program. For comparison of the thermographic, ultrasonographic and plasma fibrinogen concentrations between the groups, we will use ANOVA for time-repeated measures, which will be compared for the treatments. For comparison of the von Frey filaments test we will use two-way ANOVA for time-repeated measures comparing all treatments between the animals. (AU)