RESUMO Subprodutos da piscicultura poderiam representar matéria-prima em larga escala para implantes xenógenos úteis à regeneração óssea. O objetivo desta pesquisa foi analisar a biocompatibilidade e a biodegradação de membranas de gelatina (G) e apatita (A) de tilápia do Nilo. Camundongos Swiss machos adultos foram submetidos a implante subcutâneo de biocompósitos derivados de peles e escamas em diferentes concentrações: 60%G:40%A (G1), 70%G:30%A (G2) e 80%G:20%A (G3). Como controles, foram usados membrana colágena comercial (C+) ou cirurgia sem implante (C-). Eutanásia foi realizada em 1, 3 ou 9 semanas para análise histológica de critérios inflamatórios, de reparo e integridade de cada material. A análise estatística dos dados não paramétricos foi realizada pelo teste de Kruskal-Wallis e pós-teste de Dunn, com p<0,05. Resultados in vivo durante o período experimental demonstraram melhora progressiva na biocompatibilidade, com G1 e G2 suavemente irritantes e G3 não irritante, tal como o C+. Houve diferenças significativas entre grupos teste e controles quanto a presença de neutrófilos, linfócitos, macrófagos, células gigantes do tipo corpo estranho, neovascularização e tecido conjuntivo. Ainda, houve decréscimo da integridade dos implantes, onde G1 manteve maior estabilidade do que G3 e G2, porém inferior ao C+. Todos os biocompósitos se mostraram biocompatíveis e parcialmente biodegradáveis. O G1 sugere maior potencial de uso como membrana osteopromotora, com seu desempenho biológico associado à maior concentração mineral frente à fase orgânica. Futuros estudos ortotópicos a longo prazo serão conduzidos para investigar sua ação osteopromotora.

ABSTRACT Fish farming by-products could represent large-scale raw materials for xenogeneic implants that could be used for bone regeneration. The objective of this research was to analyze the biocompatibility and biodegradation of gelatin (G) and apatite (A) membranes from Nile tilapia. Adult male Swiss mice underwent subcutaneous implantation of biocomposites derived from skins and scales in different concentrations: 60%G:40%A (G1), 70%G:30%A (G2) and 80%G:20%A (G3). Commercial collagen membrane (C+) or implantless surgery (C-) were used as controls. Euthanasia was performed at 1, 3 or 9 weeks for histological analysis of the inflammatory and repair criteria as well as the integrity of each material. The statistical analysis of non-parametric data was performed using the Kruskal-Wallis test and post-hoc Dunn test, with p<0.05. In vivo results during the experimental period demonstrated progressive improvement in biocompatibility, with G1 and G2 being slightly irritating and G3 non-irritating, just like C+. There were significant differences between test and control groups regarding the presence of neutrophils, lymphocytes, macrophages, foreign body giant cells, neovascularization and connective tissue. There was also a decrease in the integrity of the implants, where G1 maintained greater stability than G3 and G2, but less than C+. All biocomposites proved to be biocompatible and partially biodegradable. G1 suggests greater potential for use as an osteopromoting membrane, with its biological performance associated with higher mineral concentration compared to the organic phase. Future long-term orthotopic studies will be conducted to investigate its osteopromoting action.

ABSTRACT Hydrogels have potential as soil conditioners due to their high capacity to retain water and mitigate soil salinity. However, investigations under saline conditions are necessary because there are losses in both water absorption and salinity mitigation depending on the composition of hydrogel and ions involved in salinity. In this work, we studied a commercial hydrogel in two experiments. The first experiment was conducted in the laboratory to evaluate the absorption by the hydrogel of water with electrical conductivity (EC) of 0.5, 1.5, 3.0, and 4.5 dS m–1, promoted by NaCl. The second experiment was conducted in a greenhouse in a 2 × 4 factorial scheme (with and without hydrogel × EC of the first experiment). Although salinity reduced water absorption by hydrogel by 84 %, the polymer applied in a sandy soil under saline conditions reduced water losses by 58 %. However, hydrogel did not increase the final soil moisture (~ 0.10 g g–1). The polymer reduced Na+ concentration in leachate from 1,499 to 1,219 mg L–1 at the highest salinity level (4.5 dS m–1), but it increased Na+ soil availability by 0.1 mg kg–1 in comparison with polymer absence. Hydrogel application increased Na+ content in plants from 9 to 13 mg kg–1 at the highest salinity, while K+ content was 10 to 16 mg kg–1 lower than that observed without a polymer. Hydrogel 0.07 % (w/w) reduced maize biomass, indicating damage by monovalent ions, compromising the polymer potential under salinity.

Abstract Background: Injection of Hylan G-F20 (HY) into joints may provoke local flares, which mechanisms may involve reaction to protein contaminants. We have previously developed a protein-free saline-soluble galactomannan derived from guar gum (GM) that displays both analgesia and chondroprotection in experimental osteoarthritis (OA). We now demonstrate that both GM and Hylan G-F20 (HY) promote mild synovitis with cytokine release after intra-articular injection. Methods: Mice received 100 μg/25 μL GM or HY or saline into the knees. Joint pain was evaluated using von Frey test; cell influx, interleukin (IL)-1, IL-6, and CXCL-1 (pg/mL) levels were assessed in joint lavage at 6 h. Synovia were excised for histopathology. Results: Neither GM nor HY after being given into mice knee joints induced pain albeit promoting mild cell influx into joint washings as well as mild synovitis at histology, with no damage to the underlying cartilage. HY but not GM promoted IL-1 release into mice joints. Both compounds induced IL-6 and CXCL-1 release. Conclusion: Intra-articular injection of HY or GM promote acute transient synovitis whilst not provoking detectable significant joint damage. Local administration of these polysaccharides induces acute intra-articular release of inflammatory cytokines, which may account for joint flares following viscosupplementation.

RESUMO: Sobremesas lácteas contendo galactomanana de semente de Caesalpinia pulcherrima tiveram suas propriedades reológicas estáticas e dinâmicas avaliadas. As variações nos índices de consistência (K) e comportamento de fluxo (n), assim como na tensão inicial de fluxo e na tixotropia das sobremesas mostraram o efeito da galactomanana sobre a tensão de cisalhamento e viscosidade aparente dos sistemas lácteos. Todas as sobremesas exibiram comportamento pseudoplástico, com índices de comportamento de fluxo (n) variando entre 0,06 e 0,37. A reologia dinâmica dos grupos MD (alto teor de sólidos) e MD/2 (metade do teor de sólidos), mostrou G’ > G’’ e módulos dependentes da frequência e da temperatura. Alterações químicas nos componentes das sobremesas foram observadas a 50° C em virtude da maior sensibilidade dos valores de G’ e G” a partir dessa temperatura. A galactomanana de C. pulcherrima contribuiu para o desenvolvimento de géis mais fortes e resistentes nas sobremesas lácteas, bem como mostrou sinergismo com amido, proteína do leite e sacarose.

ABSTRACT: Dairy desserts containing Caesalpinia pulcherrima seed galactomannan were evaluated to determine their static and dynamic rheological behaviors. Variations in consistency index (k), flow behavior (n), yield stress and thixotropy of the desserts indicated that the galactomannan caused an increase in the shear stress and apparent viscosity of the system. All samples exhibited shear-thinning behavior with flow behavior index values (n) between 0.06 and 0.37. Dynamic rheological behavior was evaluated for MD (high solid levels) and MD/2 (half the amount of solids) groups, and both G’ and G’’ moduli were depended on the frequency. The MD and MD/2 groups showed variations in the elastic modulus (G’) throughout the temperature range (mainly at 50 °C), showing greater sensitivity at high temperatures. C. pulcherrima galactomannan was able to promote synergism with starch, milk protein and sucrose and to improve the development of stronger and more resistant gels.