ABSTRACT
Hydrogels have been studied as promising materials in different biomedical applications such as cell culture in tissue engineering or in wound healing. In this work, we synthesized different nanocellulose-alginate hydrogels containing cellulose nanocrystals, TEMPO-oxidized cellulose nanocrystals (CNCTs), cellulose nanofibers or TEMPO-oxidized cellulose nanofibers (CNFTs). The hydrogels were freeze-dried and named as gels. The nanocelluloses and the gels were characterized by different techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA), while the biological features were characterized by cytotoxicity and cell growth assays. The addition of CNCTs or CNFTs in alginate gels contributed to the formation of porous structure (diameter of pores in the range between 40 and 150 µm). TEMPO-oxidized cellulose nanofibers have proven to play a crucial role in improving the dimensional stability of the samples when compared to the pure alginate gels, mainly after a thermal post-treatment of these gels containing 50 wt % of CNFT, which significantly increased the Ca2+ crosslinking density in the gel structure. The morphological characteristics, the mechanical properties, and the non-cytotoxic behavior of the CNFT-alginate gels improved bioadhesion, growth, and proliferation of the cells onto the gels. Thus, the alginate-nanocellulose gels might find applications in tissue engineering field, as for instance, in tissue repair or wound healing applications.
ABSTRACT
A placa dentária é considerada um fator etiológico chave associado a gengivite decorrente. A sua remoção pode ser difícil em pacientes que possuam coordenação motora deficiente ou quaisquer outros problemas. Então, ouso do bochecho como adjunto da escovação no controle da placa bacteriana e da gengivite pode aumentar os benefícios no controle de placa dental. Um estudo de fase II foi utilizado para avaliar a aderência, a apreciação e a aceitabilidade de um enxaguatório bucal sem álcool contendo 5% de própolis verde (EPV 5%) no controle de placa e gengivite durante três meses. Cada indivíduo, ao final do estudo, respondeu a um questionário sobre a apreciação e aceitabilidade do enxaguante bucal. Vinte e um pacientes completaram o estudo, apesar de a maioria deles terem considerado o sabor do EPV 5% desagradável. Eles ficaram satisfeitos com o produto e apontaram as mudanças positivas na saúde bucal após o período de tratamento. Sendo assim, a adesão foi satisfatória (≥80%) sem diferença estatisticamente significante entre os períodos de bochecho da manhã da noite.
Dental plaque is considered a key etiological factor associated with arising gingivitis. Its removal can be difficult in pacients with lack of coordination or any other problems. Then, the use of mouthrinse as adjunct to toothbrushing in control of plaque and gingivitis might increase the benefits of controlling dental plaque. A phase II study was used to evaluate the compliance, appreciation and acceptability of an alcohol-free mouthwash contain 5% green propolis (MGP 5%) in control of plaque and gingivitis for three months. Each subject, at the end of the study, answered a questionnaire about appreciation and acceptance of the mouthwash. Twenty one subjects completed the study, although most of them felt the taste of MGP 5% unpleasant. They were satisfied with the product, pointing positive changes in the oral health after the treatment period. Then, the compliance was satisfactory (≥ 80%) with no statistically significant difference between the periods of rinsing in the morning and at night
