A new material to prevent urethral damage after implantation of artificial devices: an experimental study

ABSTRACT Objective To validate the application of the bacterial cellulose (BC) membrane as a protecting barrier to the urethra. Materials and Methods Forty female Wistar rats (four groups of 10): Group 1 (sham), the urethra was dissected as in previous groups and nothing applied around; Group 2, received a 0.7cm strip of the BC applied around the urethra just below the bladder neck; Group 3, received a silicon strip with the same dimensions as in group 2; Group 4, had a combination of 2 and 3 groups being the silicon strip applied over the cellulosic material. Half of the animals in each group were killed at 4 and 8 months. Bladder and urethra were fixed in formalin for histological analysis. Results Inflammatory infiltrates were more intense at 4 months at lymphonodes (80% Grade 2), statistically different in the group 2 compared with groups 1 (p=0.0044) and 3 (p=0.0154). At 8 months, all samples were classified as grade 1 indicating a less intense inflammatory reaction in all groups. In group 2, at 8 months, there was a reduction in epithelial thickness (30±1μm) when com-pared to groups 1 (p=0.0001) and 3 (p<0.0001). Angiogenesis was present in groups 2 and 4 and absent in group 3. In BC implant, at 4 and 8 months, it was significant when comparing groups 4 with 1 (p=0.0159). Conclusion BC membrane was well integrated to the urethral wall promoting tissue remodeling and strengthening based on morphometric and histological results and may be a future option to prevent urethral damage.

Caracterização físico-química do extrato fluido e seco por nebulização de Symphytum officinale L. / Phisycal chemistry characterization of fluid and dry nebulization extract of Symphytum officinale L.

O artigo reporta a obtenção do extrato fluido de Symphytum officinale L., e posterior secagem por nebulização, e a caracterização físico-química por técnicas termogravimétricas, espectroscópicas e cromatográficas. O adjuvante de secagem utilizado foi hidroxietilcelulose na concentração de 1,5 por cento. Foi observado que o processo de secagem por nebulização, nas condições operacionais estabelecidas, não influenciou as características dos constituintes do extrato seco em relação ao extrato fluido pelas técnicas utilizadas.

This work reports the obtaining of the Symphytum officinale L. fluid extract dried by spray-drying and its physicochemical characterization by thermogravimetric analysis, spectroscopic and chromatographic techniques. Hydroxyethylcellulose at 1,5 percent was used as technological adjuvant. We observed that the drying process by spray-dryer, on the established operational conditions, did not have influence in the characteristics of the dry extract constituents in relation to the fluid extract by the used techniques.