Self-healing pectin/cellulose hydrogel loaded with limonin as TMEM16A inhibitor for lung adenocarcinoma treatment.

Lung cancer as one of the highest incident malignant tumors did not receive satisfactory chemotherapy due to lack of specific drug targets and targeted drugs. This study screened a new effective lung tumor inhibitor limonin from herbal medicine, which inhibited proliferation and promoted apoptosis of lung adenocarcinoma cells by targeting specific high expressed TMEM16A ion channel. Moreover, a novel biodegradable self-healing hydrogel was prepared from acylhydrazide functionalized carboxymethyl cellulose (CMC-AH) and oxidized pectin (pec-CHO) to reduce the side effects of the limonin to the body. The hydrogels showed fast gelation, good biocompatibility and sustained limonin release property. The limonin-loaded hydrogel significantly inhibited the growth of lung adenocarcinoma in xenografts mice because the limonin inhibited the proliferation, migration and promoted apoptosis of LA795 cells, and eliminated the acute toxicity through sustained release from the hydrogel. Combined the antitumor performance of the limonin and sustained release of pec-CHO/CMC-AH hydrogel, this limonin/hydrogel system achieved satisfactory antitumor effect and eliminated side effects in vivo. Therefore, this system has great potential application for enhanced lung adenocarcinoma therapy.

Self-healing hydrogel based on polyphosphate-conjugated pectin with hemostatic property for wound healing applications.

Self-healing hydrogels have important application in hemostasis and wound repairing. In this research, pectin based self-healing hydrogel was fabricated with conjugated polyphosphate for hemostatic and wound healing applications. The hydrogel formed without any stimulus and hydrogel kept its biocompatibility; at the same time, the hydrogel degraded completely by enzyme and in vivo. The polyphosphate conjugated hydrogel also showed self-healing property and sustained release performance with strong coagulation characteristic. More importantly, the in vivo experiment revealed that the polyphosphate conjugated hydrogel reduced the blood loss and hemostasis time in hemorrhage model; meanwhile, the hydrogel accelerated the wound repairing rate of the open wound by preventing bacterial invasion. Altogether, the PolyP conjugated hemostatic pectin-based hydrogel is a good candidate as wound dressing material applied in clinic or open wound repairing.

Composting with biochar or woody peat addition reduces phosphorus bioavailability.

Biochar and woody peat have been recognized as an additive to reduce carbon and nitrogen loss during composting. Yet little is known about their influences on the transformation of phosphorus (P) fractions in composting. This study investigated the quantitative and qualitative changes in different P forms during composting with adding biochar or woody peat using sequential extraction and P K-edge X-ray absorption near-edge structure (XANES). The results showed that compost products from the treatment with adding woody peat had a higher HA/FA (the ratio of humic acid to fulvic acid) compared to biochar treatment and the control, suggesting that the addition of woody peat might benefit the humification process of composting. Sequential extraction and XANES illustrated that adding biochar or woody peat limited the P availability. Biochar increased the proportion of Pi and woody peat decreased the conversion from Po to Pi compared to the control. Structural equation modeling and redundancy analysis suggested that biochar improved the refractory P based on the indirect effects of NH4+-N by regulating microbial community, while woody peat was beneficial for Po accumulation by affecting humic acid. Taken together, this research provides basis for regulating the nutrient level of carbon, nitrogen, and phosphorus in composts and reducing environmental risks.

Surfactin and fengycin B extracted from Bacillus pumilus W-7 provide protection against potato late blight via distinct and synergistic mechanisms.

Potato late blight caused by Phytophthora infestans is one of the most serious plant diseases worldwide. Cyclic lipopeptides (CLPs) extracted from Bacillus strains exhibit a promising effect in the biocontrol of a variety of phytopathogens. However, the specific inhibitory effects and underlying mechanisms of CLPs against P. infestans are poorly understood. In this study, we showed that Bacillus pumilus W-7 can inhibit the growth of P. infestans mycelium. Two metabolites from W-7, surfactin and fengycin B, were identified using MS/MS. Fengycin B inhibited mycelium growth by inducing mycelium deformations, oxidative damage, and mitochondrial dysfunction. Surfactin induced potato plant defense responses by increasing the expression of the biocontrol genes (pod, pal, and cat) and their enzyme activities (POD, PAL, and CAT). Also, surfactin and fengycin B could exhibit a synergistic inhibitory effect on P. infestans. Taken together, our findings indicate that B. pumilus W-7 and its CLPs are potential environmentally friendly and effective biocontrol agents for the preservation of potato crops. KEY POINTS: • Lipopeptides of surfactin and fengycin B are extracted from Bacillus pumilus W-7. • Fengycin B inhibits Phytophthora infestans mycelium growth in a direct manner. • Surfactin induces potato plant defense responses to control late blight.