Bacterial cellulose to reinforce urethrovesical anastomosis. A translational study

Abstract Purpose: To evaluate the efficacy of the cellulosic exopolysaccharide membrane (CEM) as a urethral reinforcement for urethrovesical anastomosis. Methods: Twenty eight rabbits were submitted to urethrovesical anastomosis with or without CEM reinforcement. The animals were divided into 4 groups: C7, CEM7, C14 and CEM14: (C= only anastomosis or CEM = anastomosis + CEM), evaluated after 7 weeks, and 14 weeks. The biointegration and biocompatibility of CEM were evaluated according to stenosis, fistula, urethral wall thickness, urethral epithelium, rate of inflammation and vascularization. Results: Between the two experimental groups, the difference in the number of stenosis or urinary fistula was not statistically significant. The morphometric analysis revealed preservation of urethral lumen, well adhered CEM without extrusion, a controlled inflammatory process and implant vascularization. The urothelium height remained constant over time after CEM reinforcement and the membrane wall was thicker, statistically, after 14 weeks. Conclusion: The absence of extrusion, stenosis or urinary fistula after 14 weeks of urethrovesical anastomosis demonstrates cellulosic exopolysaccharide membrane biocompatibility and biointegration with tendency to a thicker wall.

Cost-effective production of bacterial cellulose using acidic food industry by-products

Abstract To reduce the cost of obtaining bacterial cellulose, acidic by-products of the alcohol and dairy industries were used without any pretreatment or addition of other nitrogen sources. Studies have shown that the greatest accumulation of bacterial cellulose (6.19 g/L) occurs on wheat thin stillage for 3 days of cultivation under dynamic conditions, which is almost 3 times higher than on standard Hestrin and Schramm medium (2.14 g/L). The use of whey as a nutrient medium makes it possible to obtain 5.45 g/L bacterial cellulose under similar conditions of cultivation. It is established that the pH of the medium during the growth of Gluconacetobacter sucrofermentans B-11267 depends on the feedstock used and its initial value. By culturing the bacterium on thin stillage and whey, there is a decrease in the acidity of the waste. It is shown that the infrared spectra of bacterial cellulose obtained in a variety of environments have a similar character, but we found differences in the micromorphology and crystallinity of the resulting biopolymer.

Efficacy of bacterial cellulose membrane for the treatment of lower limbs chronic varicose ulcers: a randomized and controlled trial / Eficácia da membrana de celulose bacteriana no tratamento de úlceras venosas de membros inferiores: estudo randomizado e controlado

ABSTRACT Objective: to evaluate the efficacy of Bacterial Cellulose (BC) membrane dressings in the treatment of lower limb venous ulcers. Methods: we carried out a prospective, randomized, controlled study of 25 patients with chronic venous ulcer disease in the lower limbs from the Angiology and Vascular Surgery Service of the Federal University of Pernambuco Hospital and from the Salgado Polyclinic of the County Health Department, Caruaru, Pernambuco. We randomly assigned patients to two groups: control group, receiving dressings with triglyceride oil (11 patients) and experimental group, treated with BC membrane (14 patients). We followed the patients for a period of 120 days. Results: There was a reduction in the wound area in both groups. There were no infections or reactions to the product in any of the groups. Patients in the BC group showed decreased pain and earlier discontinuation of analgesic use. Conclusion: BC membrane can be used as a dressing for the treatment of varicose ulcers of the lower limbs.

RESUMO Objetivo: avaliar a eficácia de curativos com membrana de Celulose Bacteriana (CB) no tratamento de úlceras venosas de membros inferiores. Métodos: estudo prospectivo, randomizado e controlado de 25 pacientes com úlceras decorrentes de doença venosa crônica nos membros inferiores provenientes do Serviço de Angiologia e Cirurgia Vascular do Hospital de Clínicas da Universidade Federal de Pernambuco e da Policlínica do Salgado da Secretaria Municipal de Saúde, Caruaru, Pernambuco. Os pacientes foram distribuídos aleatoriamente em dois grupos: grupo controle, que recebeu curativos com óleo de triglicerídeos (11 pacientes) e grupo experimental, tratado com membrana de CB (14 pacientes). Os pacientes foram acompanhados por um período de 120 dias. Resultados: houve uma redução na área de ferida em ambos os grupos. Não houve infecção ou reações ao produto em nenhum dos grupos. Pacientes do grupo CB mostraram diminuição da dor e interrupção mais precoce do uso de analgésicos. Conclusão: a membrana de CB pode ser usada como curativo para o tratamento de úlceras varicosas dos membros inferiores.

Down-Regulation of Cellulose Synthase Inhibits the Formation of Endocysts in Acanthamoeba

Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.

Short-Cut Pathway to Synthesize Cellulose of Encysting Acanthamoeba

The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.

Estudo experimental da resposta tecidual à presença de celulose produzida por Acetobacter xylinum no dorso nasal de coelhos / Experimental study of the tissue reaction caused by the presence of cellulose produced by Acetobacter Xylinum in the nasal dorsum of rabbits

Vários materiais são propostos para reconstrução nasal, não havendo consenso sobre qual o melhor. A manta de celulose produzida por bactéria pode ser mais um elemento para adição cartilaginosa. Não há estudos deste material no dorso nasal. OBJETIVO: Avaliar a resposta tecidual à presença da celulose bacteriana no dorso nasal de coelhos. MATERIAL E MÉTODO: Foram utilizados 22 coelhos Nova Zelândia, sendo que em 20 deles foi implantada a manta de celulose no dorso nasal e em 2 controles nada foi feito. Foram acompanhados por um período de três e seis meses, sendo então retirados as regiões do dorso nasal e narinas dos coelhos e realizado estudo histopatológico levando em consideração parâmetros definidos de condição inflamatória como congestão vascular, intensidade do processo inflamatório e presença de exsudato purulento. RESULTADOS: O processo inflamatório manteve-se estável, demonstrando sua relação com o procedimento cirúrgico, e não com a presença da manta de celulose. Nos demais parâmetros estudados não houve diferença estatisticamente significante. CONCLUSÃO: A manta de celulose de Acetobacter xylinum mostrou boa biocompatibilidade e manteve-se estável no decorrer do tempo de estudo, podendo ser considerada um bom material para uso na elevação do dorso nasal.

Several materials have been proposed for nasal reconstruction. There is no consensus on which is the best. The cellulose blanket produced by bacteria may be a possible cartilaginous addition element to the nose. AIM: to study tissue reaction to cellulose in the dorsal nose of rabbits. MATERIALS AND METHODS: 22 New Zealand rabbits were used. In 20 a cellulose blanket was implanted in the nasal dorsum and 2 served as controls. They were followed up through a period of three and six months, after which their nostrils and nasal dorsums were removed and histological studies were carried out on them, considering defined parameters of inflammation such as vascular congestion, intensity of the inflammatory process and presence of purulent exudate. RESULTS: The inflammatory process remained stable, showing its relationship with the surgical procedure and not with the presence of the cellulose blanket. There were no statistical differences in the other parameters. CONCLUSION: The cellulose blanket produced by Acetobacter xylinum presented good biocompatibility, remained stable during the entire study period, and could be considered a good material for elevating the nasal dorsum.

Investigação dos efeitos do emprego de celulose biossintética e matriz dérmica humana acelular na correção da meningomielocele intra-útero: estudo comparativo em fetos de ovelhas / Comparative study of byosinthetic cellulose (BC) and human acellular dermal matrix (HADM) in the in utero repair of myelomeningocele in fetal sheep model

Objetivo: Estudar os efeitos do emprego de dois materiais consideravelmente diferentes quanto à origem e custo na correção intra-uterina da meningomielocele criada experimentalmente em feto de ovino. Métodos: Em 36 fetos de ovinos foi criado um defeito aberto de tubo neural, com 75 de dias de gestação. Os casos foram divididos em três grupos: o controle onde o defeito não foi corrigido, grupo corrigido A onde o material utilizado para cobrir a medula exposta foi a matriz dérmica humana acelular (MDHA) e o grupo corrigido B onde o material foi a celulose biossintética (CB). Após a correção realizada com 100 dias, os fetos eram mantidos intra-útero até o termo da gestação. Os sacrifícios foram realizados com 140 dias e a coluna fetal era submetida à análise macro e microscópica onde foi observada a aderência dos materiais à pele, medula ou tecido nervoso remanescente. Resultados: Na fase inicial (piloto), 11 fetos foram operados e 4 sobreviveram (37%). Na segunda fase (estudo) 25 fetos foram operados e 17 sobreviveram (68%). No grupo de estudo, 6 fetos não foram submetidos à correção (grupo controle), 11 casos foram corrigidos e ocorreu 1 perda fetal. Do total de 10 casos, 4 constituíram o grupo A e 6, o grupo B. À macroscopia observou-se deslizamento da pele e tecidos subjacentes sobre a CB em todos os casos onde ela foi empregada e isto não ocorreu em nenhum dos casos onde a MDHA foi utilizada. Para comparar a aderência, foram considerados 4 casos do grupo A e 4 do grupo B. A aderência, caracterizada pela migração de células do hospedeiro e proliferação de vasos para dentro da MDHA, foi observada em 100% dos casos do grupo A e em nenhum caso no grupo B (p < 0,05). No grupo B observou-se formação de uma camada de fibroblastos ao redor do material, protegendo a medula, caracterizando a formação de uma "neoduramater"...

Purpose: The aim of this study was to compare the effectiveness of two dura-mater substitutes, namely human acellular dermal matrix (HADM) and biosynthetic cellulose (BC), in repairing, in utero, surgically-induced meningomyelocele (MMC) in fetal sheep. Methods: A neural tube defect was created at 74-77 days gestation in 36 fetal sheep. They were divided into 3 groups, the control group that did not receive pre-natal corrective surgery, and the other two groups that received corrective surgery using HADM (Group A) or BC (Group B). Both materials were used as a dura-mater substitutes between the neural tissue and the sutured skin. Correction was performed at gestation day 100 and the fetuses were maintained in utero until term. Sheep were sacrificed on gestation day 140. The fetal spine was submitted to macro and microscopic analysis. At microscopy, adherence of the material to the skin and neural tissue was analyzed. Results: In the initial phase (pilot), experimentally-induced MMC was performed on 11 fetuses and 4 survived (37%). In the second phase (study), 25 fetuses received surgery and 17 survived (68%). In the study group, 6 fetuses did not undergo repair (control group), 11 cases were submitted to corrective surgery (experimental group) and one fetal loss occurred. Of the surviving cases in the experimental group, 4 constituted Group A and 6 in Group B. Macroscopically, skin and underlying tissues where easily displaced from the BC in all cases it was used; in contrast, HADM adhered to these tissues. To compare the adherence, 4 cases from Group A and 4 in Group B were studied. We observed adherence, host cell migration and vessel proliferation into the HADM all sections from Group A and this aspect was not present in any cases in Group B (p < 0.05). In Group B, we also observed that a new fibroblast layer formed around the BC thus protecting the medulla and constituting a "neoduramater"...