RESUMO

This study aimed to compare different protocols (Protocol 1: P1; Protocol 2: P2; Protocol 3: P3; Protocol 4: P4) for the extraction of spongin-like collagen (SC) from marine sponges. The SEM micrographs demonstrated a fibrillar structure for the extracts from Chondrilla caribensis and the nodular/particulate aggregates for Aplysina fulva. FTIR showed for all samples peaks similar to collagen for both species. For C. caribensis, the extracts obtained using P2, P3, and P4 protocols presented higher values of extraction yield, TPQ, and GAGs. P2 and P4 showed higher values of SC concentration and for antioxidant analysis. For A. fulva, P2, P3, and P4 provided a higher extraction yield besides an increase in the antioxidant assay. For both species, no difference was observed for Col quantification and TPQ analysis; also, higher values of GAGs were found using P2 and P4. Fibroblast proliferation observed for C. caribensis was lower for P1 on day 1 and for P2 and P3 on day 3 (for 50%) compared to the control group. There was a significant reduction in fibroblast cell proliferation for all A. fulva extracts evaluated. It can be concluded that protocols P2 and P4 were more efficient for extracting SC from C. caribensis.

RESUMO

ABSTRACT This study aimed to determine the effectiveness of LLLT in decreasing the lung inflammatory process in septic rats. A total of 32 male Wistar rats were divided into four groups (n=8): control group (CG), sepsis 24h (S24), sepsis and LLLT with 30 J/cm² (S24L30); sepsis and LLLT with 65 J/cm² (S24L65). The irradiation was performed immediately after surgery in the anterior region of the trachea and ventral regions of the chest, bilaterally, just below the ribs. Histological analysis of lung tissue was performed and the number of inflammatory cells was quantified. The S24 group showed an increase of inflammatory cells compared to the CG (p <0.01); S24L30 increased the number of inflammatory cells, while S24L65 decreased this number compared to S24 (both p<0.05); S24L65 had a lower number of inflammatory cells compared to S24L30 (p<0.01). In conclusion, LLLT at a specific energy dose (30J / cm²) was capable of decreasing the number of inflammatory cells in acute lung tissue inflammation due to sepsis.

RESUMO O objetivo do estudo foi determinar a eficácia da LLLT na diminuição do processo inflamatório pulmonar em ratos sépticos. Foram utilizados 32 ratos machos Wistar divididos em quatro grupos (n=8): controle (CG); sepse 24h (S24); sepse e tratamento com LLLT 30 J/cm² (S24L30); sepse e tratamento com LLLT 65 J/cm² (S24L65). A irradiação foi realizada imediatamente após a cirurgia na região anterior de traqueia e nas regiões ventrais do tórax, bilateralmente, logo abaixo das costelas. Foi realizada análise histológica do tecido pulmonar e o número de células inflamatórias foi quantificado. O grupo S24 apresentou um aumento de células inflamatórias comparado ao CG (p <0,05); S24L30 aumentou o número de células inflamatórias, enquanto S24L65 diminuiu este numero em relação ao S24 (ambos p <0,05); S24L65 diminui o numero de células inflamatórias comparado ao S24L30 (p<0.01). Concluiu-se que LLLT em dose específica de energia (30J/cm²) foi capaz de diminuir o número de células inflamatórias no tecido pulmonar em fase aguda da sepse.

RESUMEN El objetivo del estudio es determinar la eficacia de la LLLT en la disminución del proceso inflamatorio pulmonar en ratones sépticos. Se utilizaron 32 ratones machos Wistar divididos en cuatro grupos (n=8): control (CG); sepsis 24h (S24); sepsis y tratamiento con LLLT 30 J/cm2 (S24L30); sepsis y tratamiento con LLLT 65 J/cm2 (S24L65). Se realizó la irradiación inmediatamente después de la cirugía en la región anterior de la tráquea y en las regiones ventrales del tórax, bilateralmente, debajo de las costillas. Se realizó un análisis histológico del tejido pulmonar y se cuantificó el número de células inflamatorias. El grupo S24 presentó un aumento de células inflamatorias en comparación al CG (p <0,05); S24L30 aumentó el número de células inflamatorias, mientras S24L65 disminuyó este número en relación al S24 (ambos p <0,05); S24L65 disminuyó el número de células inflamatorias en comparación al S24L30 (p<0,01). Se concluye que la LLLT en dosis específica de energía (30J/cm2) ha sido capaz de disminuir el número de células inflamatorias en el tejido pulmonar en fase aguda de la sepsis.

RESUMO

The objective of this study was to assess the effects of 780-nm low-level laser therapy at different periods of 7, 14 and 21 days after cryolesion, including the dose (10 or 50 J/cm(2)), to promote a better muscle repair evidenced by histopathological and immunohistochemical analyses. Fifty-four male rats were divided into three groups: injured control group (CG)-injured animals without any treatment; injured 780-nm laser-treated group, at 10 J/cm(2) (G10); and injured 780-nm laser-treated group, at 50 J/cm(2) (G50). Each group was divided into three subgroups (n = 6): 7, 14 and 21 days post-injury. Histopathological findings revealed better organised muscle fibres in the G10 and G50 during the periods of 7 and 14 days compared to the CG. The G10 and G50 during the 7 days showed a significant reduction (p < 0.05) of lesion area compared to the CG, without differences between groups treated for 14 and 21 days. The G10 showed an increase of the amount of vessels after 14 days compared to the G50, but not in relation to controls. With regard to the immunohistochemical analyses of the MyoD factor, the G10 and G50 during the 7 days showed higher concentrations of immunomarkers than controls. Myogenin immunomarkers were similarly observed at days 7 and 14 in all the three groups analysed, whereas immunomarkers were found in none of the groups after 21 days of laser therapy. The results showed that laser, regardless the applied dose, has positive effects on muscle repair.

Assuntos

RESUMO

The aim of this study was to evaluate the effects of 660 nm low-level laser therapy (LLLT) on muscle regeneration after cryolesion in rat tibialis anterior muscle. Sixty-three Wistar rats were divided into a control group, 10 J/cm(2) laser-treated group, and 50 J/cm(2) laser-treated group. Each group formed three subgroups (n = 7 per group), and the animals were sacrificed 7, 14, or 21 d after lesion. Histopathological findings revealed a lower inflammatory process in the laser-treated groups after 7 d. After 14 d, irradiated animals at both fluences showed higher granulation tissue, new muscle fibers, and organized muscle structure. After 21 d, full tissue repair was observed in all groups. Moreover, irradiated animals at both fluences showed smaller necrosis area in the first experimental period evaluated. MyoD immunoexpression was observed in both treated groups 7 d postinjury. Myogenin immunoexpression was detected after 7 and 14 d. The higher fluence increased the number of blood vessels after 14 and 21 d. These results suggest that LLLT, at both fluences, positively affects injured skeletal muscle in rats, accelerating the muscle-regeneration process.

Assuntos

RESUMO

After an introduction showing the growing interest in glasses and glass-ceramics as biomaterials used for bone healing, we describe a new biomaterial named Biosilicate. Biosilicate is the designation of a group of fully crystallized glass-ceramics of the Na2O-CaO-SiO2-P2O5 system. Several in vitro tests have shown that Biosilicate is a very active biomaterial and that the HCA layer is formed in less than 24 hours of exposure to "simulated body fluid" (SBF) solution. Also, in vitro studies with osteoblastic cells have shown that Biosilicate disks supported significantly larger areas of calcified matrix compared to 45S5 Bioglass, indicating that this bioactive glass-ceramic may promote enhancement of in vitro bone-like tissue formation in osteogenic cell cultures. Finally, due to its special characteristics, Biosilicate has also been successfully tested in several in vivo studies. These studies revealed that the material is biocompatible, presents excellent bioactive properties, and is effective to stimulate the deposition of newly formed bone in animal models. All these data highlight the huge potential of Biosilicate to be used in bone regeneration applications.

Assuntos

RESUMO

This study evaluated the biocompatibility of Biosilicate® scaffolds by means of histopathological, cytotoxicity, and genotoxicity analysis. The histopathologic analysis of the biomaterial was performed using 65 male rats, distributed into the groups: control and Biosilicate®, evaluated at 7, 15, 30, 45, and 60 days after implantation. The cytotoxicity analysis was performed by the methyl thiazolyl tetrazolium (MTT) assay, with various concentrations of extracts from the biomaterial in culture of osteoblasts and fibroblasts after 24, 72, and 120 h. The genotoxicity analysis (comet assay) was performed in osteoblasts and fibroblasts after contact with the biomaterial during 24, 72, and 96 h. In the histopathology analysis, we observed a foreign body reaction, characterized by the presence of granulation tissue after 7 days of implantation of the biomaterial, and fibrosis connective tissue and multinucleated giant cells for longer periods. In the cytotoxicity analysis, extracts from the biomaterial did not inhibit the proliferation of osteoblasts and fibroblasts, and relatively low concentrations (12.5% and 25%) stimulated the proliferation of both cell types after 72 and 120 h. The analysis of genotoxicity showed that Biosilicate® did not induce DNA damage in both lineages tested in all periods. The results showed that the Biosilicate® scaffolds present in vivo and in vitro biocompatibility.

Assuntos

RESUMO

The purpose of this study was to investigate the effects of Bioglass 45S5 and Biosilicate, on bone defects inflicted on the tibia of rats. Fifty male Wistar rats were used in this study, and divided into five groups, including a control group, to test Biosilicate and Bioglass materials of two different particle sizes (180-212 microm or 300-355 microm). All animals were sacrificed 15 days after surgery. No significant differences (P > 0.05) were found when values for Maximal load, Energy Absorption and Structural Stiffness were compared among the groups. Histopathological evaluation revealed osteogenic activity in the bone defect for the control group. Nevertheless, it seems that the amount of fully formed bone was higher in specimens treated with Biosilicate (granulometry 300-355 microm) when compared to the control group. The same picture occurred regarding Biosilicate with granulometry 180-212 microm. Morphometric findings for bone area results (%) showed no statistically significant differences (P > 0.05) among the groups. Taken together, such findings suggest that, Biosilicate exerts more osteogenic activity when compared to Bioglass under subjective histopathological analysis.

Assuntos