Fabrication of smart stimuli-responsive mesoporous organosilica nano-vehicles for targeted pesticide delivery.

It is highly desirable to construct stimuli-responsive nanocarriers for improving pesticides targeting and preventing the pesticides premature release. In this work, a novel redox and α-amylase dual stimuli-responsive pesticide delivery system was established by bonding functionalized starch with biodegradable disulfide-bond-bridged mesoporous silica nanoparticles which loaded with avermectin (avermectin@MSNs-ss-starch nanoparticles). The results demonstrated that the loading capacity of avermectin@MSNs-ss-starch nanoparticles for avermectin was approximately 9.3 %. The starch attached covalently on the mesoporous silica nanoparticles could protect avermectin from photodegradation and prevent premature release of active ingredient. Meanwhile, the coated starch and disulfide-bridged structure of nanoparticles could be decomposed and consequently release of the avermectin on demand when nanoparticles were metabolized by glutathione and α-amylase in insects. The bioactivity survey confirmed that avermectin@MSNs-ss-starch nanoparticles had a longer duration in controlling Plutella xylostella larvae compared to avermectin emulsifiable concentrate. In consideration of the superior insecticidal activity and free of toxic organic solvent, this target-specific pesticide release system has promising potential in pest management.

Liang Y ，Gao Y ，Wang W ，Dong H ，Tang R ，Yang J ，Niu J ，Zhou Z ，Jiang N ，Cao Y ... -  《-》

Fabrication of abamectin-loaded mesoporous silica nanoparticles by emulsion-solvent evaporation to improve photolysis stability and extend insecticidal activity.

Feng J ，Chen W ，Shen Y ，Chen Q ，Yang J ，Zhang M ，Yang W ，Yuan S ... -  《-》

A comparison of mesoporous silica nanoparticles and mesoporous organosilica nanoparticles as drug vehicles for cancer therapy.

Mesoporous silica nanoparticles (MSNs) are promising drug carriers for use in cancer treatment owing to their excellent biocompatibility and drug-loading capacity. However, MSN's incomplete drug release and toxic bioaccumulation phenomena limit their clinical application. Recently, researchers have presented redox responsive mesoporous organosilica nanoparticles containing disulfide (S-S) bridges (ss-MONs). These nanoparticles retained their ability to undergo structural degradation and increased their local release activity when exposed to reducing agents. Disulfide-based mesoporous organosilica nanoparticles offer researchers a better option for loading chemotherapeutic drugs due to their effective biodegradability through the reduction of glutathione. Although the potential of ss-MONs in cancer theranostics has been studied, few researchers have systematically compared ss-MONs with MSNs with regard to endocytosis, drug release, cytotoxicity, and therapeutic effect. In this work, ss-MONs and MSNs with equal morphology and size were designed and used to payload doxorubicin hydrochloride (DOX) for liver cancer chemotherapy. The ss-MONs showed considerable degradability in the presence of glutathione and performed comparably to MSNs on biocompatibility measures, including cytotoxicity and endocytosis, as well as in drug-loading capacity. Notably, DOX-loaded ss-MONs exhibited higher intracellular drug release in cancer cells and better anticancer effects in comparison with DOX-loaded MSNs. Hence, the ss-MONs may be more desirable carriers for a highly efficient and safe treatment of cancer.

Yue J ，Luo SZ ，Lu MM ，Shao D ，Wang Z ，Dong WF ... -  《-》

Study of UV-shielding properties of novel porous hollow silica nanoparticle carriers for avermectin.

The shielding protection given by self-prepared porous hollow silica nanoparticles (PHSN) to pesticides from degradation by UV light was investigated using avermectin as a model pesticide. It was demonstrated that PHSN carriers with a shell thickness of approximately 15 nm and a pore diameter of 4-5 nm have an encapsulation capacity of 625 g kg(-1) for avermectin using a supercritical fluid loading method. PHSN carriers exhibited remarkable UV-shielding properties for avermectin. This was affected by the intensity of UV light, the pH and the temperature of the release medium. Rises in UV intensity, pH and/or temperature reduced the UV protection of PHSN for avermectin. In addition, avermectin loaded into the inner core of the PHSN carriers was released slowly into the release medium for about 30 days following a typical sustained-release pattern. It thus appears that PHSN carriers have a promising future in applications requiring sustained pesticide release.

Li ZZ ，Chen JF ，Liu F ，Liu AQ ，Wang Q ，Sun HY ，Wen LX ... -  《PEST MANAGEMENT SCIENCE》

α-Amylase triggered carriers based on cyclodextrin anchored hollow mesoporous silica for enhancing insecticidal activity of avermectin against Plutella xylostella.

α-Amylase-responsive carrier for controlled release of avermectin (AVM) was prepared based on α-cyclodextrin (α-CD) anchored hollow mesoporous silica (HMS) using α-CD as a capping molecule. The release of AVM was studied at different temperatures, pH values and in the presence or absence of α-amylase. The results revealed that the AVM-encapsulated controlled release formulation (AVM-CRF) has a drastic enzymatic dependence, an excellent encapsulation efficacy reaching 38%, and outstanding UV and thermal shielding ability. The AVM-CRF biological activity survey shows excellent toxicological properties against Plutella xylostella larvae, which confirms that α-CD caps could be uncapped enzymatically in vivo and release AVM, inducing P. xylostella larval death. AVM-CRF has a notable capability to keep 0.6 mg L-1 AVM biologically active until 14th day with 83.33% mortality of the target insect, which was 40% higher than that of treated with AVM commercial formulation. The study provides a theoretical basis for the application of pesticide reduction.

Kaziem AE ，Gao Y ，Zhang Y ，Qin X ，Xiao Y ，Zhang Y ，You H ，Li J ，He S ... -  《-》