Effect of sugarcane biopolymer in vocal fold of rabbits. Comparative study with calcium hydroxyapatite

PURPOSE: To compare the inflammatory reaction caused by the injection of a sugarcane biopolymer (SCB) into the vocal fold of rabbits with that caused by calcium hydroxyapatite (CaH). METHODS: CaH (Radiesse(r)) and SCB gel were injected respectively into the right and left vocal cords of thirty rabbits. The rabbits were distributed into two equal groups and sacrificed at three and twelve weeks after injection. We then evaluated the intensity of the inflammatory reaction, plus levels of neovascularization, fibrogenesis and inflammatory changes in the vocal mucosa. RESULTS: The vocal cords injected with CaH had a stronger inflammatory reaction by giant cells in both study periods. The SCB group had a more intense inflammatory involvement of polymorphonuclear cells three weeks after injection. SCB caused a higher level of neovascularization compared with CaH three weeks after the procedure. CONCLUSION: Whereas calcium hydroxyapatite triggers a more intense and lasting inflammatory reaction mediated by giant cells, sugarcane biopolymer causes a greater response from polymorphonuclear leukocytes, as well as higher levels of vneoascularization three weeks after injection. .

Hydrogel of polysaccharide of sugarcane molasses as carrier of bone morphogenetic protein in the reconstruction of critical bone defects in rats

PURPOSE: To evaluate the benefit of using carriers such as the biopolymer gel (hidrogel of polysaccharide of sugarcane molasses) associated with the bone morphogenetic proteins (BMP's) in the repair of critical bone defects in calvaria of Wistar rats. METHODS: Forty-two rats were submitted to a surgical calvaria bone defects. These animals were divided into two experimental groups, positive control group and negative control group. The Group I the calvaria defect was filled up with biopolymer gel, biological membrane, BMP and lyophilized graft. The Group II was treated with biopolymer gel, BMP and lyophilized graft. And the group III (positive control group) was treated with BMP, lyophilized graft and biological membrane. In the negative control group (Group IV) a defect was made in the rat calvaria and the animals were sacrificed immediately after the surgery. The animals of experimental groups and positive control group were slaughtered after subsequent periods of 90 and 180 days. In these periods, the histological analysis and image assessment by cone bean tomographic imaging were obtained. RESULTS: There was highest bone tissue formation with statistically significant results in the groups that associated biopolymer gel and membrane (Group I), followed by the group III (BMP, lyophilized graft and biological membrane). The lower bone formation occurred in the group not using the sugarcane biopolymer gel (Group II). The radiolucent areas of the analyzes of 180 days among the groups studied were respectively, 14.98 mm², 26.65 mm² and 35.81 mm². CONCLUSION: The biopolymer gel showed to be an excellent bone morphogenetic protein carrier, probably by facilitating the controlled release of these proteins in the process of bone repair.

Use of a gel biopolymer for the treatment of eviscerated eyes: experimental model in rabbits / Uso de um biopolímero na forma gel para o tratamento de olhos eviscerados: modelo experimental em coelhos

PURPOSE: To evaluate histologically the integration process of cellulose gel produced by Zoogloea sp when implanted into rabbits' eviscerated eyes. METHODS: This experimental study employed 36 eyes of 18 rabbits subjected to evisceration of their right eyes. The sclerocorneal bag was sutured and filled with biopolymer from sugar cane in the gel state. All animals were clinically examined by biomicroscopy until the day of their sacrifice which occurred on the 7th, 30th, 60th, 90th, 120th, or 240th day. The eyeballs obtained, including the left eyes considered controls were sent for histopathological study by optical macroscopy and microscopy. Tissue staining techniques used included hematoxylin-eosin, Masson trichrome (with aniline), Gomori trichrome, Van Gienson, Picrosirius red, and periodic acid-Schiff (PAS). RESULTS: No clinical signs of infection, allergy, toxicity, or extrusion were observed throughout the experiment. The corneas were relatively preserved. Macroscopic examination revealed a decrease of ~ 8% in the volume of the bulbs implanted with the biopolymer. After cutting, the sclerocorneal bag was solid, compact, elastic, and resistant to traction, with a smooth and whitish surface, and showed no signs of necrosis or liquefaction. The episcleral tissues were somewhat hypertrophied. The histological preparations studied in different colors revealed an initial lymphoplasmacytic infiltration, replaced by a fibroblastic response and proliferation of histiocytes, along with formation of giant cells. Few polymorphonuclearneutrophils and eosinophils were also found. Neovascularization and collagen deposition were present in all animals starting from day 30; although on the 240th day of the experiment the chronic inflammatory response, neovascularization and collagen deposition had not yet reached the center of the implant. CONCLUSION: In this model, the cellulose gel produced by Zoogloea sp proved to be biocompatible and integrated into the orbits. Morphometric, immunohistochemical and biodegradability studies should be performed in the future.

OBJETIVOS: Avaliar histologicamente o processo de integração do gel da celulose produzida pela Zoogloe asp implantado em olhos eviscerados de coelhos. MÉTODOS: Estudo experimental utilizando 36 olhos de 18 coelhos. Todos eles tiveram seus olhos direitos eviscerados. A bolsa escleral foi suturada e preenchida com biopolimero da cana de açúcar, no estado gel. Todos os animais foram examinados clinicamente, sob biomicroscopia, até o dia de seus sacrifícios e enucleações que aconteceram no 7º, 30º, 60º,90º,120º e 240º dia. Os bulbos obtidos, inclusive os esquerdos, considerados controles, foram encaminhados para estudo histopatológicos de macroscopia e microscopia óptica. As colorações pela hematoxilina-eosina, tricômio de Masson (com anilina), tricômio de Gomori, Van Gienson e Picrosirius red e ácido periódico de Schiff (PAS) foram usadas. RESULTADOS: Durante o experimento não foram observados sinais clínicos de infecção, alergias, intoxicação ou extrusão. As córneas apresentavam-se relativamente preservadas. Exame macroscópico revelou uma diminuição de aproximadamente 8% no volume dos bulbos nos quais o biopolímero foi implantado. O corte do saco escleral mostrou um conteúdo sólido, compacto, elástico, resistente à tração, com superfície lisa e brancacenta. Não foram observados sinais de necrose, ou liquefação. O tecido epiescleral estava algo hipertrofiado. As preparações histológicas estudadas, nas diversas colorações, revelaram uma infiltração linfomonomorfonuclear inicial, substituída posteriormente por uma resposta fibroblástica e proliferação de histiócitos com formação de células multinucleadas gigantes. Foram também encontrados poucos polimorfonucleares neutrófilos e eosinófilos. A partir do 30º dia houve proliferação vascular e deposição de calágeno em todos os espécimes estudados, embora, no 240º dia do experimento, a resposta inflamatória crônica, a neovascularização e a deposição do colágeno não tinham ainda atingido o centro do implante. CONCLUSÃO: Neste modelo, o gel da celulose produzido pela Zoogloea sp, mostrou-se biocompatível e integrado às órbitas. Estudos morfométrico, imuno-histoquímico e de biodegradabilidade devem ser realizados futuramente.