Ursolic acid is widely used as an effective anticancer drug for the treatment of various cancers. However, its poor water solubility, short circulation time in vivo, and lack of targeting have made it a burden for clinical applications. We report a self-assembled folate-modified pectin nanoparticle for loading ursolic acid ([email protected] NPs) and embed the anticancer drug hydroxycamptothecin to achieve synergistic treatment with ursolic acid. In addition, the galactose residue of the pectin molecule can be recognized by the asialoglycoprotein receptor on the surface of the liver cancer cell, promoting the rapid penetration and release of [email protected] NPs intracellularly. In particular, the introduction of multiarm polyethylene glycol can improve the uniformity (106 nm) and concealment of the nanoparticles and avoid the early release of the drug or the toxicity to normal cells. [email protected] NPs have a high drug loading (7.27 wt %) and embedding efficiency (19.84 wt %) and continuous circulation up to 80 h, leading to more apoptosis (91.61%). [email protected] NP intracellular drug delivery will be a promising strategy.

Pine wilt disease is a devastating forest disaster caused by Bursaphelenchus xylophilus, which has brought inestimable economic losses to the world’s forestry due to lack of effective prevention and control measures. In this paper, a porous structure CuBTC was designed to deliver avermectin (AM) and a control vector insect Japanese pine sawyer (JPS) of B. xylophilus, which can improve the biocompatibility, anti-photolysis and delivery efficacy of AM. The results illustrated the cumulative release of pH-dependent AM@CuBTC was up to 12 days (91.9%), and also effectively avoided photodegradation (pH 9.0, 120 h, retention 69.4%). From the traceable monitoring experiment, the AM@CuBTC easily penetrated the body wall of the JPS larvae and was transmitted to tissue cells though contact and diffusion. Furthermore, AM@CuBTC can effectively enhance the cytotoxicity and utilization of AM, which provides valuable research value for the application of typical plant-derived nerve agents in the prevention and control of forestry pests. AM@CuBTC as an environmentally friendly nanopesticide can efficiently deliver AM to the larval intestines where it is absorbed by the larvae. AM@CuBTC can be transmitted to the epidemic wood and dead wood at a low concentration (10 mg/L).

Background: Trunk-boring pests (TBPs) are an important type of forest pest, TBPs not only feed on the branches and trunks of trees, but also spread quarantine diseases in forests. However, because the larvae of TBPs live inside the trunk and are well concealed, prevention and control are difficult. The lack of effective control methods leads to the death of many trees in forests. In this study, a novel nanopesticide featuring high bioactivity and slow-release properties was developed to control TBPs. Thiacloprid (THI), which is commonly used to control Coleoptera species, was used as a model pesticide. Results: The oleophobic properties of bovine serum albumin (BSA) were exploited to encapsulate the hydrophobic pesticide THI by self-assembly, and the size of the obtained nanoparticles, THI@BSA·NPs, was approximately 23 nm. The loading efficiency reached 70.4%, and THI@BSA·NPs could be released continuously for over 15 days, with the cumulative release reaching 93.5%. The fluorescein isothiocyanate (FITC)-labeled nanoparticles were evenly distributed in the digestive tract and body surface of a typical TBPs, M. alternatus, and the stomach and contact toxicities increased by 33.7% and 25.9%, respectively, compared with those of free THI. Furthermore, the results showed that the transport efficiency of THI@BSA·NPs was highest at a concentration of 50 μg/mL, and the THI@BSA·NPs content in the trunk, from to lower to higher layers, was 8.8, 8.2, 7.6, and 5.8 μg/g. At the same time, THI@BSA·NPs also exhibited high transport efficiency in dead trees. Conclusion: The transport efficiency and toxicity of the active ingredients are the key factors for the control of TBPs. This work provided idea for the application of biological delivery system encapsulated hydrophobic pesticides. The novel self-assembled THI@BSA·NPs have promising potential for sustainable control of TBPs.

Pine wilt disease (PWD) is an infestation caused by pine wood nematodes (PWN, Bursaphelenchus xylophilus), and has caused significant disruption to forest ecosystems worldwide. Trunk injection is effective in controlling PWD, but the long-term use of abamectin (AVM) and other drugs in large quantities has caused resistance problems, and the annual trunk injections have caused some damage to the trunks themselves. In order to reduce drug resistance and damage to the tree trunks, in this study, dendritic mesoporous silica nanoparticles (DMSNs) were prepared by using a “one-pot” method, which is the easiest to industrialise, and AVM@DMSNs nano-pesticides with a uniform particle size, high loading efficiency (80.2%) and sustained release were prepared by physical adsorption. And cellular uptake and toxicity experiments were carried out on sf9 cells, and the results showed that the nano DMSNs could be enriched on sf9 cells and had good inhibition of cellular activity. The lethality of the nano-pesticides AVM@DMSNs and AVM on PWN was investigated using the insect dip method. The results showed that the corrected mortality rate of AVM@DMSNs was significantly higher than that of free AVM within 72 h. In addition, AVM@DMSNs compounded with a plant essential oil bark penetrant could be applied locally outside the bark and penetrate the drug into the tree to achieve the purpose of injury-free drug delivery, which could effectively reduce the damage of perforation injection on the tree and provide a new way for the control of forest pests.