Synthesis of polymeric core/shell microspheres with spherical virus-like surface morphology by Pickering emulsion

Lignin-Modified Electronegative Epoxy Resin Nanocarriers Effectively Deliver Pesticides against Plant Root-Knot Nematodes (Meloidogyne incognita)

It is highly desirable to fabricate a pesticide delivery system with excellent permeability to reduce the damage caused by root-knot nematodes in the soil. In this work, a novel electronegative pesticide nanocarrier was established by bonding anionic lignosulfonate with epoxy resin nanocarriers, which were loaded with abamectin (Aba). The results demonstrated that nanoparticles were negatively charged (-38.4 mV) spheres with an average size of 150 nm, and the encapsulation efficiency of nanocarriers for Aba was 93.4%. Polymer nanocarriers could prevent premature release of Aba and protect active ingredients from microbiological degradation. The adsorption strength of the soil to Aba loaded in nanocarriers was reduced by 6 to 10 times, so nanonematicides have remarkable soil mobility. Meanwhile, nanoparticles could easily penetrate the roots and nematodes. The application test confirmed that the control effect of this nanopesticide was 26-40% higher than that of the other agrochemicals. In consideration of its superior bioactivity and utilization rate, this pesticide delivery system has promising potential to control root-knot nematodes and improve the pesticide's utilization efficiency.

TO/TMMP-TMTGE Double-Healing Composite Containing a Transesterification Reversible Matrix and Tung Oil-Loaded Microcapsules for Active Self-Healing

Thermoset epoxies are widely used due to their excellent properties, but conventional epoxies require a complicated and time-consuming curing process, and they cannot self-healed, which limits their applications in self-healing materials. Extrinsic and intrinsic self-healing materials are applied in various fields due to their respective characteristics, but there is a lack of comparison between the two types of healing systems. Based on this, a thiol-epoxide click reaction catalyzed by an organic base was introduced to achieve the efficient preparation of thiol-epoxy. Furthermore, tung oil (TO)-loaded microcapsules were introduced into the thiol-epoxy matrix of dynamic transesterification to obtain a TO/TMMP-TMTGE self-healing composite with an intrinsic-extrinsic double-healing system. For comparison, a TMMP-TMTGE self-healing material with an intrinsic healing system was also prepared, which contained only thiol and epoxy curing chemistries. The effect of the core/shell ratio on the morphology, average particle size, and core content of TO-loaded microcapsules was studied. It was found that when the core/shell ratio was 3:1, the average particle size of the microcapsules was about 99.8 μm, and the microcapsules showed good monodispersity, as well as a core content of about 58.91%. The differential scanning calorimetry (DSC) results showed that the TO core was successfully encapsulated and remained effective after encapsulation. Furthermore, scanning electron microscopy (SEM), atomic force microscopy (AFM), tensile tests, and electrochemical tests were carried out for the two types of self-healing materials. The results showed that the TO/TMMP-TMTGE composite and TMMP-TMTGE material both had self-healing properties. In addition, the TO/TMMP-TMTGE composite was superior to the TMMP-TMTGE material due to its better self-healing performance, mechanical strength, and corrosion protection performance.

Tobacco Mosaic Virus-Functionalized Mesoporous Silica Nanoparticles, a Wool-Ball-like Nanostructure for Drug Delivery

The design of versatile tools to improve cell targeting and drug delivery in medicine has become increasingly pertinent to nanobiotechnology. Biological and inorganic nanocarrier drug delivery systems are being explored, showing advantages and disadvantages in terms of cell targeting and specificity, cell internalization, efficient payload delivery, and safety profiles. Combining the properties of a biological coating on top of an inorganic nanocarrier, we hypothesize that this hybrid system would improve nanoparticle-cell interactions, resulting in enhanced cell targeting and uptake properties compared to the bare inorganic nanocarrier. Toward this goal, we engineered a hierarchical assembly featuring the functionalization of cargo-loaded mesoporous silica nanoparticles (MSNPs) with tobacco mosaic virus (TMV) as a biological coating. The MSNP functions as a delivery system because the porous structure enables high therapeutic payload capacity, and TMV serves as a biocompatible coating to enhance cell interactions. The resulting MSNP@TMV nanohybrids have a wool-ball-like appearance and demonstrate enhanced cell uptake, hence cargo delivery properties. The MSNP@TMV have potential for medical applications such as drug delivery, contrast agent imaging, and immunotherapy.

Convenient synthesis of uncovered imprinted microspheres by Ganoderma lucidum spore-stabilized pickering emulsion polymerization and their enhanced recognition of spiramycin

In this work, a new and simple method was developed for the synthesis of uncovered and high-selectivity spiramycin-based molecularly imprinted microspheres (SP-MIMs) by Pickering emulsion polymerization using spiramycin as templates. And surprisingly the solid particles were absent on the surface of imprinted microspheres, which can be ascribed to the Ganoderma lucidum spores (GLS): they were firstly selected to be the stabilizers for the Pickering emulsion in this new strategy. Through a series of adsorption experiments, the uncovered SP-MIMs were proven to possess more excellent selective recognition and removal ability for template SP in aqueous solution. And SP-MIMs could be reused for many times without significant loss of adsorption capacity, indicating the satisfactory regeneration performance. Therefore, SP-MIMs can be employed as a promising adsorbent for the selective removal of SP from aqueous media, and this strategy will contribute to overcoming the shortcomings of stabilizer particles on the surface of the as-prepared imprinting microspheres, because these solid particles lack the special selective recognition activity of template molecules, and may disturb the adsorption effect of imprinting microspheres.

In this work, a new and simple method was developed for the synthesis of uncovered and high-selectivity spiramycin-based molecularly imprinted microspheres (SP-MIMs) by Pickering emulsion polymerization using spiramycin as templates.

Porous epoxy phenolic novolac resin polymer microcapsules: Tunable release and bioactivity controlled by epoxy value

Microcapsules (MCs) prepared with diverse wall material structures may exhibit different properties. In this study, MCs were fabricated with three kinds of epoxy phenolic novolac resins (EPNs), which possessed unique epoxy values as wall-forming materials by interfacial polymerization. The effects of the EPN types on the surface morphology, particle size distribution, encapsulation efficiency, thermal stability as well as release behavior and bioactivity of the MCs were investigated. In all three samples, the MCs had nearly spherical shapes with fine monodispersities and sizes in the range of 7-30 μm. Scanning electron microscopy (SEM) images showed that some small pores (ranging from 50 nm to 400 nm) appeared on the microcapsule surfaces and that the porosity decreased with an increasing of epoxy value. The X-ray diffractometer (XRD) analysis indicated that the cured EPN shells had larger degrees of crosslinking with higher epoxy values, leading to better thermal stabilities. Moreover, the release rate of the core material (pendimethalin) decreased with an increasing of epoxy value and thus resulted in a lower herbicidal control efficacy. The results of our research will enhance the potential application of EPNs as smart wall-forming materials to prepare porous MCs for controlled release.

Paclitaxel-loaded PLGA microspheres with a novel morphology to facilitate drug delivery and antitumor efficiency

A novel morphological PTX-PLGA-MS with microporous surface and porous internal structures to enhance drug loading, delivery and antitumor efficiency.

Microencapsulation through thermally sintering Pickering emulsion-based colloidosomes

Microcapsules of a phase change material synthesized by thermally sintering Pickering emulsion-based colloidosomes were demonstrated. The protocol included three steps: (1) monodispersive poly(glycidyl methacrylate) (PGMA) microspheres were prepared by dispersive polymerization and were endowed with a contact angle of 63.4° for oil-in-water Pickering stabilization by hydrolysis. (2) By phase separation during Pickering emulsion polymerization, microcapsules with a structure of a single PCM core and a PGMA armored polystyrene shell were fabricated. (3) Thermal sintering was performed to fuse the polystyrene and PGMA microspheres into an integral shell of the microcapsules. The durability of the microcapsules before and after sintering was investigated by a suspension test (in water and ethanol) and an accelerated thermal cycling test. The sintering reduced the percentage of leaked dodecanol from 19.6% to 10.3% in the suspension test in ethanol and from 10.4% to 2.8% in the accelerated cycling test. These results verified that the sintering process endowed the prepared microcapsules with better tightness and durability.

An Overview of Pickering Emulsions: Solid-Particle Materials, Classification, Morphology, and Applications

Pickering emulsion, a kind of emulsion stabilized only by solid particles locating at oil-water interface, has been discovered a century ago, while being extensively studied in recent decades. Substituting solid particles for traditional surfactants, Pickering emulsions are more stable against coalescence and can obtain many useful properties. Besides, they are more biocompatible when solid particles employed are relatively safe in vivo. Pickering emulsions can be applied in a wide range of fields, such as biomedicine, food, fine chemical synthesis, cosmetics, and so on, by properly tuning types and properties of solid emulsifiers. In this article, we give an overview of Pickering emulsions, focusing on some kinds of solid particles commonly serving as emulsifiers, three main types of products from Pickering emulsions, morphology of solid particles and as-prepared materials, as well as applications in different fields.

Thiol–isocyanate click reaction in a Pickering emulsion: a rapid and efficient route to encapsulation of healing agents

An innovative, rapid and efficient route is developed to fabricate ene loaded microcapsules via a thiol–isocyanate click reaction based on a hydrolyzed poly(glycidyl methacrylate) (PGMA) particle stabilized oil-in-water Pickering emulsion.