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BMC Oral Health ; 19(1): 263, 2019 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775860


BACKGROUND: Low-molecular-weight chitosan oligosaccharide (LMCOS), a chitosan degradation product, is water-soluble and easily absorbable, rendering it a popular biomaterial to study. However, its effect on bone remodelling remains unknown. Therefore, we evaluated the effect of LMCOS on lipopolysaccharide (LPS)-induced bone resorption in mice. METHODS: Six-week-old male C57BL/6 mice (n = five per group) were randomly divided into five groups: PBS, LPS, LPS + 0.005% LMCOS, LPS + 0.05% LMCOS, and LPS + 0.5% LMCOS. Then, the corresponding reagents (300 µL) were injected into the skull of the mice. To induce bone resorption, LPS was administered at 10 mg/kg per injection. The mice were injected three times a week with PBS alone or LPS without or with LMCOS and sacrificed 2 weeks later. The skull was removed for micro-computed tomography, haematoxylin-eosin staining, and tartrate-resistant acid phosphatase staining. The area of bone damage and osteoclast formation were evaluated and recorded. RESULTS: LMCOS treatment during LPS-induced skull resorption led to a notable reduction in the area of bone destruction; we observed a dose-dependent decrease in the area of bone destruction and number of osteoclasts with increasing LMCOS concentration. CONCLUSIONS: Our findings showed that LMCOS could inhibit skull bone damage induced by LPS in mice, further research to investigate its therapeutic potential for treating osteolytic diseases is required.

Reabsorção Óssea , Quitosana , Animais , Reabsorção Óssea/tratamento farmacológico , Quitosana/farmacologia , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oligossacarídeos , Osteoclastos , Crânio/efeitos dos fármacos , Crânio/patologia , Microtomografia por Raio-X
Adv Mater ; 31(16): e1808278, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30803049


Synthetic biology based on bacteria has been displayed in antitumor therapy and shown good performance. In this study, an engineered bacterium Escherichia coli MG1655 is designed with NDH-2 enzyme (respiratory chain enzyme II) overexpression (Ec-pE), which can colonize in tumor regions and increase localized H2 O2 generation. Following from this, magnetic Fe3 O4 nanoparticles are covalently linked to bacteria to act as a catalyst for a Fenton-like reaction, which converts H2 O2 to toxic hydroxyl radicals (•OH) for tumor therapy. In this constructed bioreactor, the Fenton-like reaction occurs with sustainably synthesized H2 O2 produced by engineered bacteria, and severe tumor apoptosis is induced via the produced toxic •OH. These results show that this bioreactor can achieve effective tumor colonization, and realize a self-supplied therapeutic Fenton-like reaction without additional H2 O2 provision.

Peróxido de Hidrogênio/metabolismo , Radical Hidroxila/metabolismo , Neoplasias/terapia , Animais , Apoptose , Reatores Biológicos , Catálise , Linhagem Celular Tumoral , Sobrevivência Celular , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Nanopartículas de Magnetita/química , Camundongos Endogâmicos BALB C , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
Appl Microbiol Biotechnol ; 102(13): 5369-5390, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29725719


Development of the next-generation biocatalyst is vital for fermentation-based industrial applications and a sustainable bio-based economy. Overcoming the major class of toxic compounds associated with lignocellulose-to-biofuels conversion is one of the significant challenges for new strain development. A significant number of investigations have been made to understand mechanisms of the tolerance for industrial yeast. It is humbling to learn how complicated the cell's response to the toxic chemicals is and how little we have known about yeast tolerance in the universe of the living cell. This study updates our current knowledge on the tolerance of industrial yeast against aldehyde inhibitory compounds at cellular, molecular and the genomic levels. It is comprehensive yet specific based on reproducible evidence and cross confirmed findings from different investigations using varied experimental approaches. This research approaches a rational foundation toward a more comprehensive understanding on the yeast tolerance. Discussions and perspectives are also proposed for continued exploring the puzzle of the yeast tolerance to aid the next-generation biocatalyst development.

Aldeídos/toxicidade , Biocombustíveis , Saccharomyces cerevisiae/efeitos dos fármacos , Fermentação