Engenharia Biomédica
URI permanente para esta coleçãohttps://repositorioacademico.universidadebrasil.edu.br/handle/123456789/915
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Item Nanocompósitos à base de Hidróxiapatita e Nanotubos de carbono como reforço em Biopolímero heterólogo de fibrina derivado de veneno de serpente para regeneração óssea(Universidade Brasil, 2021) Gouveia, Daniel Mussuri de; Cogo, José Carlos; Kido, Hueliton WilianFibrin sealants (BHF), developed from human hematological derivatives, mimic physiological clots, being widely used in general, cosmetic and postoperative surgeries due to their hemostatic and adhesive action. BHF developed from the venom of Crotalus durissus terrificus (rattlesnake) is a heterologous thrombin-like derivative that converts fibrinogen into fibrin. As it is a natural product, in gel form, biodegradable, bioabsorbent, non-toxic and non-immunogenic. On the other hand, hydroxyapatite nanocomposites (nHAp) and carbon nanotubes (NTCs), produced by chemical synthesis assisted by the ultrasound technique, present bioactivity, are not cytotoxic and have a bactericidal effect. The aim of the present work is to evaluate the mixture of hydroxyapatite-based nanocomposites and carbon nanotubes with fibrin sealant as agents in the process of accelerating bone regeneration. The production of the nanocomposites consisted, firstly, in the synthesis of NTCs with multiple walls, followed by their functionalization to the O2 plasma and purification with an acid bath. With this material ready, the composite of nHAp with NTC was produced. Then, this material was added to the BHF and the physicochemical characterization of this mixture was carried out. The pellets formed by these mixtures were analyzed and photographed under scanning electron microscopy (SEM). These mixtures were also tested in MC3T3-E1 cell cultures to verify their toxicity. For this purpose, osteoblast cells were cultured and cell viability was verified using the alamarBlue® e LIVE/DEAD® Viability/Cytotoxicity technique. Experiments were also carried out in rats, inducing bone defect in tibias and verifying bone repair. All data were analyzed using the normality test, and the parametric results were submitted to the two-way ANOVA complemented by Tukey's post-test (p≤0,05). The results showed that there was a good homogeneous distribution of the mixtures and that the most suitable mixture for in vitro tests is that of BFH+nHAp and 1% and 2% carbon nanotubes. The mixture is not cytotoxic and promoted neoformation in the fracture area, demonstrating osteogenic potential in bone fractures.Item Uso do biopolímero de fibrina heterólogo associado ou não à fotobiomodulação no processo de reparo tendíneo(Universidade Brasil, 2020) Dutra Jr., Enéas de Freitas; Tim, Carla Roberta; Amaral, Marcelo MagriIntroduction: The tendons are susceptible to injuries, and the calcaneal tendon is frequently injured. However, there is much controversy about the treatment of tendon injuries. In this perspective, the use of heterologous fibrin biopolymer (HFB), a homeostatic agent that has been used in several types of surgeries and a surgical strategy for the treatment of tendon injuries. In addition, non-surgical treatment using laser photobiomodulation therapy (PBMT) has been shown to be effective in the repair process. Objective: To evaluate the effect of heterologous fibrin biopolymer associated or not with photobiomodulation in the tendon repair process. Methodology: 84 Rattus norvegicus belonging to the Wistar strain were used. The animals were randomly divided into 4 experimental groups with N=21 animals in each: Control (CG); Heterologous fibrin biopolymer (HFB); Photobiomodulation (PBM); Heterologous fibrin biopolymer + Photobiomodulation (HFB + PBM). The groups were subdivided into 3 experimental periods: 7, 14 and 21 days. The animals received HFB immediately after partial tendon transection. PBM started the lesion induction for 24 hours and was followed for 7, 14, 21 days. For PBM, a 660 nm, 40 mW, 0.23 J and 6 second laser was used. The volume of the edema was evaluated, immediately before the tendon transection; 24 hours after tendon transection; on the day of euthanasia, following their respective experimental periods. The descriptive histopathological analysis and through the Bonar scale in the partially transected tendon region and the quantification of blood vessels were performed using slides stained with Hematoxylin and Eosin (HE). Collagen quantification was performed using slides stained with Masson's trichrome. Results: The results of the edema volume showed that, 24 hours after partial transection of the calcaneus tendon, there was no statistical difference between the experimental groups. After the three experimental periods, it was observed that the treatment groups were effective in reducing edema when compared to control. A histological analysis revealed that PBM had a major tendon injury after 7 days. However, in the periods of 14 and 21 days, the PBM had a better repair process compared to the GC, while the HFB and HFB + PBM had a better repair process when compared to the GC in the 3 experimental periods. PBM showing a greater number of blood vessels after 7, 14 and 21 days. In the quantification of collagen, there was no statistical difference between the groups, in the 3 experimental periods. Conclusion: The results obtained with the HFB and PBM treatments, granted or associated, were effective in reducing the volume of the edema, stimulating the repair process. However, the use of HFB alone is more effective in promoting the tendon repair process. Thus, this study consolidates previous studies of tendon repair with this new HFB. Clinical futures will be included to validate this proposal.