Assessment of pulmonary toxicity of potential antioxidant drug PEGylated nanoceria after intratracheal instillation in rats.

Cerium oxide (CeO2 ) nanoparticles have unique redox properties and exert excellent antioxidant effects in the biological environment. In recent years, many researchers have focused on the CeO2 nanoparticles as an effective antioxidant drug in the prevention and treatment of various diseases. However, the toxicity of CeO2 nanoparticles in vivo remains controversial and still needs intensive research. Therefore, the objective of this study is to investigate the pulmonary and systemic toxicity in rats after 14 days of exposure to the PEGylated CeO2 nanoparticles (abbreviated as CNPs; exposure dose of 2, 10, or 20 mg/kg) through a single intratracheal instillation (IT). We assessed the indicators of lung injury and the pathological damage degree of lung tissue. The bronchoalveolar lavage fluid (BALF) analysis and lung histopathology revealed the occurrence of slight pulmonary inflammation in the 20-mg/kg experimental group rats. However, the inflammation factors in the lung tissue of every group rats did not significantly increase, and the levels of superoxide dismutase (SOD) and glutathione (GSH) in lung tissue homogenate rose considerably in the experimental groups. Collectively, these results indicated that pulmonary exposure by the high dose of CNPs could induce mild pulmonary inflammation but did not cause severe systemic toxicity. Moreover, we speculate that the mechanism of pulmonary toxicity of CNPs in rats was due to the autophagic death of healthy lung epithelial cells mediated by endoplasmic reticulum stress. Our results implicate that CNPs can be safely used as an antioxidant drug for the oxidative stress pulmonary diseases.

Wirelessly Actuated Microfluidic Pump and Valve for Controlled Liquid Delivery in Dental Implants.

Enabling minimally invasive and precise control of liquid release in dental implants is crucial for therapeutic functions such as delivering antibiotics to prevent biofilm formation, infusing stem cells to promote osseointegration, and administering other biomedicines. However, achieving controllable liquid cargo release in dental implants remains challenging due to the lack of wireless and miniaturized fluidic control mechanisms. Here wireless miniature pumps and valves that allow remote activation of liquid cargo delivery in dental implants, actuated and controlled by external magnetic fields (<65 mT), are reported. A magnet-screw mechanism in a fluidic channel to function as a piston pump, alongside a flexible magnetic valve designed to open and close the fluidic channel, is proposed. The mechanisms are showcased by storing and releasing of liquid up to 52 µL in a dental implant. The liquid cargos are delivered directly to the implant-bone interface, a region traditionally difficult to access. On-demand liquid delivery is further showed by a metal implant inside both dental phantoms and porcine jawbones. The mechanisms are promising for controllable liquid release after implant placement with minimal invasion, paving the way for implantable devices that enable long-term and targeted delivery of therapeutic agents in various bioengineering applications.

Effects of fertilizer practice on fungal and actinobacterial cellulolytic community with different humified particle-size fractions in double-cropping field.

Cellulose plays an important role in maintaining or improving soil carbon (C) cycling and soil fertility of paddy field. There had close relationship between functional cellulose genes (cbhI and GH48) with characterize of soil organic matter chemical components (fulvic acid and humic acid) and soil physical fractions. However, there is still limited information about how functional cellulose degradation response to long-term fertilizer management and their relative importance for C sequestration under the double-cropping rice paddy field in southern of China. Therefore, the objective of this study were investigated the effects of 34-years long-term fertilizer regime on community abundance of cbhI and GH48 genes in five soil particle-size fractions (> 2000 µm, 2000-200 µm, 200-50 µm, 50-2 µm and 2-0.1 µm) by using polarization magic angle spinning 13C nuclear magnetic resonance spectroscopy. The field experiment was included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and without fertilizer input as a control (CK). The results showed that distribution of soil humus and cellulolytic microbial community abundance was significant increased under long-term application of crop residue and organic manure condition. And the FA, HA and HM C contents in > 2000 µm and 2000-50 µm fractions with MF, RF and OM treatments were significant higher than that of CK treatment. Meanwhile, the alkyl C and Oalkyl C groups of FA and HA in > 2000 µm fraction with MF, RF, OM and CK treatments were higher than that of the other fractions. There had higher AL% and lower ARO% of FA and HA in different particle-size fractions with MF, RF, OM and CK treatments. The results indicated that abundance of cbhI and GH48 genes in different particle-size fractions with RF and OM treatments were significant increased, compared with CK treatment. There had significant positive correlation between soil humus C components (FA and HA) with abundance of cbhI and GH48 genes, and the o-alkyl C and AL% of FA were positively correlated with abundance of cbhI and GH48 genes. As a result, the community abundance of cbhI and GH48 genes were significant increased under combined application of crop residue and organic manure with chemical fertilizer condition.