Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits.

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

Biophysical and biological characterization of intraoral multilayer membranes as potential carriers: A new drug delivery system for dentistry.

The current study developed through layer-by-layer deposition a multilayer membrane for intraoral drug delivery and analyzed the biochemical, functional, and biological properties of this membrane. For that purpose, we designed a three-layer chlorhexidine-incorporated membrane composed by pure chitosan and alginate. The biochemical, functional, and biological properties were analyzed by the following tests: degradation in saliva medium; controlled drug release; water absorption, mass loss; pH analysis; and biocompatibility through fibroblast cell viability by MTT assay. All tests were conducted at three different periods (24, 48 and 72hours). The results demonstrated that hybrid membranes composed by alginate and chitosan with glycerol had greater water absorption and mass loss in buffer solution and in artificial saliva. The controlled drug release test revealed that the hybrid membrane exhibited greater drug release (0.075%). All chlorhexidine-incorporated membranes reduced the cell viability, and chitosan membranes with and without glycerol did not interfere with fibroblast viability. The biochemical and biophysical characteristics of the designed membranes and the findings of cell viability tests indicate great potential for application in Dentistry.

Controle da carga microbiana em equipamentos de desossa utilizando limpeza a seco* / Microbial load control in deboning equipment using dry cleaning

O objetivo da presente pesquisa foi avaliar as condições higiênico-sanitárias através do nível de contaminação bacteriológica inicial e a cada duas horas consecutivas de equipamentos da sala de desossa durante a jornada de trabalho, a fim de certificar a eficácia da aplicação de limpeza a seco como procedimento padronizado de higienização operacional. Neste sentido foram coletadas amostras em triplicata para análise bacteriológica no início e a cada duas horas consecutivas da rotina diária de desossa em quatro equipamentos distintos que entram em contato direto com o produto final. Estas coletas foram realizadas durante cinco dias produtivos consecutivos totalizando cinco repetições. As coletas foram realizadas através da técnica do "swab test" e método rápido de análise. As contagens de bactérias aeróbias mesófilas se mantiveram dentro do limite aceitável estabelecido de até 1,0 log UFC.cm-2 para o horário 1 e de até 5,0 log UFC.cm-2 para os demais horários. Todas as contagens de enterobactérias se mantiveram dentro do limite aceitável estabelecido de até 3 log UFC.cm-2, notando-se que não houve diferenças (p>0,05) entre os valores encontrados nos quatro equipamentos nos diferentes horários amostrados. Sendo assim, a aplicação da limpeza a seco durante toda a jornada de trabalho na sala de desossa é eficaz para o controle da contagem de bactérias aeróbias mesófilas e de enterobactérias, portanto contribui para a produção de alimento seguro ao consumidor.

The objective of the present research were evaluate the sanitary conditions through initial bacteriological contamination level and every two consecutive hours of the deboning room equipments during workday to ensure the effectiveness of dry cleaning application as standardized procedure of operational hygiene. The samples were collected in triplicate for bacteriological analysis was proceded at baseline and every two consecutive hours of deboning daily routine in four different equipments that comes into direct contact with the end product. These samples were taken for five consecutive productive days totaling five repetitions. The collections were made using the technique of swab test and rapid method of analysis. The aerobic mesophilic counts not exceeded the acceptable limit of 1.0 log UFC.cm-2 for one hours and up to 5.0 log UFC.cm-2 for other times. All enterobacteria counts not exceeded the acceptable limit of up to 3.0 log UFC.cm-2. There were no differences among values observed from the different equipment analyzed. In addition, the application of dry cleaning throughout the workday in the deboning room was an effective control of mesophilic aerobic bacteria and enterobacteria, thus ensuring the production of safe food the consumer.

Análise bioquímica e funcional de bandagem bucal antimicrobiana / Biochemical and functional analyses in antimicrobial oral-aid

O efeito de fármacos pode ser potencializado através do desenvolvimento de novos sistemas de liberação como os sistemas mucoadesivos. Estes sistemas permanecem em contato íntimo com o tecido de absorção, às mucosas, liberando o fármaco no local de ação, com o consequente aumento da biodisponibilidade, podendo promover efeitos locais e sistêmicos. Através do desenvolvimento da bandagem bucal antimicrobiana e testadas sua eficiência sobre a cultura de algumas bactérias bucais (S. mutans e C. albicans) se fez necessário continuar os estudos desse material. O objetivo deste trabalho foi analisar as propriedades bioquímicas e funcionais da bandagem bucal antimicrobiana no que tange a: degradação no meio salivar; adequação da composição para a melhoria da aderência à mucosa bucal; desempenho quanto à liberação controlada de fármacos; absorção de água, perda de massa; medida do pH do líquido residual em diferentes períodos de tempo; citotoxicidade da bandagem em cultura de fibroblastos. As bandagens avaliadas tinham diferentes composições quitosana, quitosana com glicerol, quitosana e alginato com/sem glicerol, e todas com/sem fármaco. Através das análises realizadas foi possível observar que as bandagens que absorveram mais água em tampão foi a membrana híbrida (203%) e em saliva foi a híbrida com glicerol (30%). A membrana que perdeu mais massa em tampão e em saliva foi a híbrida com glicerol (40% e 30%), isso quer dizer que elas se decompõe e liberam suas propriedades no meio. A liberação controlada do fármaco pode avaliar que a membrana híbrida liberou de forma crescente o fármaco (0,075%), facilitando sua liberação. No teste de citotoxicidade todas as bandagens com fármaco foram citotóxicas, já as bandagens de quitosana e quitosana com glicerol promoveram o crescimento celular.

The effect of drugs may be enhanced through the development of new delivery systems as mucoadhesive systems. These systems remain in intimate contact with the tissue absorption, in this case the mucosa, releasing the drug at the site of action, with the consequent increase in bioavailability and may promote local and systemic effects. Mucoadhesion is currently explained by six theories: electronics, adsorption, wetting, diffusion, fracture and mechanics (Carvalho et al., 2010). In 2011, Kloster et al. developed an oral bandage and tested antimicrobial efficiency in the culture of some oral bacteria (S. mutans e C. albicans), the results were promising. The aim of this study was to analyze the biochemical and functional properties of oral antimicrobial bandage with respect to: the salivary environment degradation; the composition adjustment for improving the adherence to the buccal mucous membrane; the performance as to the controlled releasing of drugs; water absorption while analyzing the mass loss; pH measurements of the residual liquid in different periods of time; the plaster cytotoxicity in cell and fibroblast culture. Through the analyzes it was observed that the bandages absorb water and lose mass, it means that they decompose and release their property in the middle. The bandages with drug in viability analysis were cytotoxic cell and different concentrations of drug should be study.

Paraquat-loaded alginate/chitosan nanoparticles: preparation, characterization and soil sorption studies.

Agrochemicals are amongst the contaminants most widely encountered in surface and subterranean hydrological systems. They comprise a variety of molecules, with properties that confer differing degrees of persistence and mobility in the environment, as well as different toxic, carcinogenic, mutagenic and teratogenic potentials, which can affect non-target organisms including man. In this work, alginate/chitosan nanoparticles were prepared as a carrier system for the herbicide paraquat. The preparation and physico-chemical characterization of the nanoparticles was followed by evaluation of zeta potential, pH, size and polydispersion. The techniques employed included transmission electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy. The formulation presented a size distribution of 635 ± 12 nm, polydispersion of 0.518, zeta potential of -22.8 ± 2.3 mV and association efficiency of 74.2%. There were significant differences between the release profiles of free paraquat and the herbicide associated with the alginate/chitosan nanoparticles. Tests showed that soil sorption of paraquat, either free or associated with the nanoparticles, was dependent on the quantity of organic matter present. The results presented in this work show that association of paraquat with alginate/chitosan nanoparticles alters the release profile of the herbicide, as well as its interaction with the soil, indicating that this system could be an effective means of reducing negative impacts caused by paraquat.