Monografias, Dissertações e Teses
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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.Item Avaliação microbiológica da associação do biopolímero de fibrina com nitrato de prata(Universidade Brasil, 2021) Campos, Silvana; Nuñez, Silvia Cristina; Cogo, José CarlosFibrin sealants, also known as fibrin biopolymer (BPF), are biological matrixes from human plasma, fully resorbable, that mimic the last stages of the coagulation cascade during which fibrinogen is converted into a structured and insoluble fibrin clot. BPF developed from the snake venom Crotalus durissus terrificus, presents an excellent alternative for tissue engineering and cell modulation. Its use as a healer for venous ulcers in the lower limbs proved to be safe and potentially effective in a phase II clinical study. Objective: To investigate the antimicrobial effect of the association of fibrin biopolymer with silver nitrate. This association will allow its use in contaminated and colonized wounds, which currently leads to suspension of treatment with BPF. Methods: BPF is prepared from 2 active components and a diluent. Different concentrations of silver nitrate were mixed with the BPF components. The clots containing silver nitrate were inserted into the wells drilled on the agar in Petri dishes containing the culture medium of Mueller Hilton agar previously seeded with cultures of Staphylococcus aureus and Escherichia coli. Silver nitrate concentrations were used, forming the following groups: Control - NP1 = 1mg / mL; NP2 = 2.5mg / mL and NP3 = 5mg / mL silver nitrate; Experimental group: the same concentrations used in the control group associated with BPF and positive control with antibiotics. The presence was verified and the inhibition halo present in each of the tested plates was measured. Tests of minimum inhibitory concentration (CIM) and minimum bactericide (CBM) were carried out to establish the lowest concentration of BPF + NP and NP capable of inhibiting the tested strains. Mean and median values of diameters with measures of central tendency and standard deviation and interquartile range were considered as measures of sample dispersion and verification of antimicrobial efficacy. Results: A significant difference was observed in the halos of inhibition of treatments with NP when compared with BPF + NP. There was a statistical difference in the inhibition halos of the gram-negative bacteria in relation to the gram-positive bacteria, in the treatment with NP, NP3 showed a significant difference in relation to NP2 compared to E. coli while S. aureus did not present a statistically significant difference. BPF alone did not form an inhibition halo. BPF + NP had an inhibitory effect on the antimicrobial action of NP by 18.2% for E. coli and 13.5% for S. aureus when compared to NP treatment. The CIM found for E. coli and S. aureus when tested with GMP + NP were 7.81 and 250 µg / mL and with NP 3.9 and 7.81 µg / mL. While CBM found for BPF + NP they were 15.62 and 1000 µg / mL and for treatment with NP 7.81 and 15.62 µg / mL respectively. Conclusion: It was possible to verify by the results that the NP and BPF + NP showed antibacterial effect on the species of gram-negative and grampositive bacteria, demonstrating greater efficacy for E. coli and that the antibacterial activity of the NP was more effective than the BPF + NP. He observed that GMP when isolated has no antibacterial effect.Item Nanocompósitos à base de hidroxiapatita e nanotubos de carbono como reforço em biopolimero heterólogo de fibrina derivado do veneno de serpente para regeneração óssea(Universidade Brasil, 2021) Gouveia, Daniel Mussuri de; Kido, Hueliton Wilian; Cogo, José CarlosFibrin 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.