Efficient control of Tetranychus cinnabarinus (B.) is in challenge worldwide. Herein we report the use of an amphiphilic block copolymer, poly(ethylene oxide)-b-poly(caprolactone) (PEO–PCL), as a micellar carrier to make formulations of ricinine, a water insoluble botanical pesticide, and the tests of their physical properties and moreover the acaricidal activity on Vigna unguiculata (L). Compared to the formulations made from small molecular surfactant, e.g. Tween-80, the polymer formulations showed differentiated spreading property on T. cinnabarinus (B.) and V. unguiculata (L.) leaf surfaces, i.e. having slightly lower contact angle on the mite's integument. This contributes a relatively easy wash-off performance of the polymer formulations from the V. unguiculata (L.) leaf and meanwhile an enhanced protection to the plant in the simulated field trial. Our work thus suggests favorable characteristic of amphiphilic polymer in the future development of insecticides.

A supramolecular nanovehicle, denoted as ICG-DOX/Gd-LDH, was synthesized by the co-intercalation of indocyanine green (ICG) and doxorubicin hydrochloride (DOX) into a gallery of Gd3+-doped-layered double hydroxide (Gd-LDH) such that to achieve a chemo-photothermal synergistic therapeutic agent. The unique structure of Gd-LDH can not only stabilize the photothermal agent ICG to enhance the photothermal efficiency, but also hamper the recombination between electron and holes, leading to the generation of more reactive oxygen species (ROS) under irradiation in the NIR range. Together with the loading capacity of DOX, ICG-DOX/Gd-LDH exhibited excellent combinatorial effects on tumor growth inhibition in both in vitro studies on HeLa cell line and in vivo tests over tumor-bearing mouse models. Moreover, it showed ideal ability for long-term tracing of the carrier distribution via either MRI or fluorescence imaging. Thus, this study indicates that Gd-LDH is a promising platform for the construction of multifunctional formulations, especially theranostic nano-systems for cancer treatment.

In this work, an injectable composite hydrogel was synthesized via a unique way of crosslinking glycol chitosan (GC) with silica nano-particles (SiNP) through non-chemical interactions, and was then applied as a kind of wound dressing. Gelation was achieved through the incorporation of SiNPs with the GC segments in aqueous solution, therefore strictly confining the movement of the solubilized polymer chains. Rheology tests showed that the sol–gel transition and the moduli of the hydrogel were influenced by the composition of the two components, the size of the nano-particles and the conformation of the polymers. Using such a strategy, tissue adhesion properties of GC were well-preserved in the GC/SiNP hydrogel and therefore it gains gluey properties toward biological tissues as demonstrated through the adhesion of two pieces of mouse skin, obtaining a lap-shear stretching force of ca. 90 kPa. This characteristic, together with the injectability, allowed the hydrogel to be administrated directly on the wound site and to fill the wound area. Meanwhile, the hydrogel also works as a carrier of protein and cells. The in situ encapsulation of fibroblasts enabled the promising properties of the GC/SiNP hydrogel to be used for treating full-thickness skin defects in a mouse model, resulting in the favorable growth of hair follicles and microvessels, hence reducing the risk of scar formation.

Herein we report a facile route for the preparation of surface patterned dynamic hydrogel films, which are not only a matrix to encapsulate one type of cell in 3D but also a substrate to support aligned aggregates of magnetic silica rods to adhere another type of cell in 2D. This enables the composite hydrogel films to be flexible scaffolds for engineering multi-cellular tissues.

Polymeric micelles of amphiphilic block copolymers have been studied for decades for their application as a targeting delivery agent of anti-tumor drugs. However, the targeting micelles may cause an immunological response because of the surface distributed ligands. In this work, mixed micelles were developed to improve the specificity of cancer cell uptake under tumor-acidic conditions. This was achieved by the co-assembly of an active targeting amphiphilic polymer, i.e. cyclic (Arg-Gly-Asp-D-Phe-Lys) c(RGDfK) functionalized poly(ethylene oxide)-b-poly(ε-caprolactone) (cRGD-PEO-b-PCL), and a pH sensitive drug conjugate, i.e. benzoic-imine linked PEGylated doxorubicin (PEG-DOX). Because the PEG-DOX is cleavable at the extracellular pH of a solid tumor, the characteristics of the mixed micelles turn from “stealthy” to cancer cell-affinitive due to the detachment of PEG from the micelle surface and hence allow the action of the c(RGDfK) in the cRGD-PEO-b-PCL with the cancer cell membrane. Besides, the mixed micelles exhibited the capacity for encapsulating hydrophobic drugs such as paclitaxel to form a combination formulation. Our results indicate that co-assembly is a facile but efficient strategy to coordinate the characteristics of each individual component and thus provide combinatorial functions to the delivery system.

Janus hollow spheres, with different compositions compartmentalized onto both interior and exterior surfaces of the same shell and P25 nanoparticles encapsulated in the cavities, are synthesized by the ultrasonic spray method to selectively enrich desired reagents in a confined environment for further reaction.

A fluoropoly(ether ether ketone) (FPEEK) demonstrating blue fluorescence was developed as a flexible, transparent membranous matrix for the incorporation of quantum dots (QDs) to fabricate a composite photoluminescent film which is promising as a self-referenced temperature sensor.

Protein nanogels were synthesized via a one-step reaction procedure by crosslinking urokinase with benzaldehyde bifunctionalized poly(ethylene glycol). The crosslinked architecture significantly enhances the stability of urokinase against enzyme degradation in comparison with the core–shell structural PEGylated proteins. Meanwhile, bioactivity of the urokinase incorporated in the nanogels can be adjusted by varying the chain length of the corsslinking polymer. With a shorter crosslinker the bioactivity of the uPA nanogels is seriously restricted under physiological conditions. However, the restricted bioactivity can be completely launched by either enlarging the mesh size of the nanogel by using longer crosslinkers, or treating the nanogels in endosomal conditions to dissociate the nanogel structure due to the reversible conjugation chemistry.

Herein we report a coassembly method toward the preparation of pH-sensitive polymeric vesicular aggregates, using comb-shaped amphiphilic polymers, i.e., cholate grafted poly(l-lysine) (PLL-CA), with an amphiphilic poly(ethylene glycol)–doxorubicin conjugate (PEG-DOX). Because the drug conjugate includes a low-pH labile bond, i.e., benzoic imine, the permeability of the coassembled polymeric vesicles can be tuned by changing either the PLL-CA/PEG-DOX weight ratio or the environmental pH from 7.4 to 6.5. Furthermore, at lower pH values such as 5.0, the vesicles destabilize. The pH sensitivity leads to enhanced uptake of the vesicles by cancer cells (MCF-7) under a condition close to the extracellular environment of solid tumor (pH = 6.5) and subsequent efficient endosome escape after the endocytosis.

Composite microgel capsules were fabricated through an ultrasonic spray accompanied by in situ surface crosslinking between glycol chitosan (GC) and benzaldehyde capped poly(ethylene glycol) (OHC–PEG–CHO) in the nebulized droplets. The methodology enables a selective one-pot encapsulation for different functional species inside the interior cavity or within the shell. Herein lithium phthalocyanine (LiPc) microcrystals and citrate stabilized iron oxide (Fe3O4) nanoparticles were selected as model materials for the functionalization, which led to the electron paramagnetic resonance (EPR) and superparamagnetic dual performance of the composite microgel capsules. This shows the potential of the microgel capsules in diagnosis and targeting delivery applications.

Injectable hydrogels with pH and temperature triggered drug release capability were synthesized based on biocompatible glycol chitosan and benzaldehyde-capped poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO). Aqueous solutions of the above polymers formed hydrogel under physiological conditions, allowing a desirable injectability, through the formation covalent benzoic-imine bond with pH and temperature changes. Rheological characterization demonstrated that the gelation rate and the moduli of the hydrogels were able to be tuned with chemical composition as well as pH and temperature of the polymer solution. Both hydrophobic and hydrophilic drugs could be incorporated inside the hydrogel through the in situ gel forming process and undergo a controlled release by altering pH or temperature. In vivo tests proved the formation and biocompatibility of the hydrogel in rat model.

We have reported a new approach to fabricate mesoporous silica composite nanosheets by milling the corresponding hollow spheres. The mesoporous nanosheets are amphiphilic, and can be well dispersible both in water and oil, serving as particulate emulsifiers in o/w or w/o systems. The mesoporous silica can assist other functional materials, for example metal and carbon to be dispersible. An example is given to demonstrate the support of catalysts for a heterogeneous catalytic aerobic oxidation of benzyl alcohols by Pt/silica composite nanosheets.

We demonstrate that multifuctional drug carriers, e.g., polymeric micelles, for tumor-specific uptake and intracellular delivery can be generated from the pH-dependent progressive hydrolysis of a novel benzoic-imine linker in the micelle-forming amphiphilic polymer. The linker, hence the micelle, is stable at physiological pH, partially hydrolyzes at the extracellular pH of the solid tumor, and completely hydrolyzes at the endosomal pH. Meanwhile, the surface property of the micelle converts from neutral to positively charged due to the generation of amino groups from the cleavage of the imine bond at tumor pH. The ionization on the surface facilitates the cellular uptake of the micelles through the electrostatic interaction between the micelle and the cell membrane. Subsequently, at the endosomal pH, with more complete cleavage of the polymer the micellar structure dissociates, and the system becomes very membrane-disruptive, inferring an enhanced intracellular delivery capability via the endosomal pathway.

Amphiphilic polycations with a “stealth” cationic nature have been designed and synthesized by the PEGylation of polycationic amphiphile via a novel pH responsible benzoic imine linker. The linkage is stable in aqueous solution at physiological pH but cleaves in slight acidic conditions such as the extracellular environment of solid tumor and endosomes. The polymeric micelle formed from the amphiphilic “stealth” polycation contains a pH-switchable cationic surface driven by the reversible detachment/reattachment of the shielding PEG chains due to the cleavage/formation process of the imine linkage. At physiological pH, the micellar surface was shielded by the PEG corona, leading to lower cytotoxicity and less hemolysis, whereas in a mild acidic condition like in endosomes or solid tumors, the deshielding of the PEG chains exposed the positive charge on the micellar surface and retained the membrane disrupting ability. The amphiphilic “stealth” polycation is potentially useful as a drug targeting system toward tumors via endocytosis and trafficked through the endosomal pathway.

A fluoropoly(ether ether ketone) (FPEEK) demonstrating blue fluorescence was developed as a flexible, transparent membranous matrix for the incorporation of quantum dots (QDs) to fabricate a composite photoluminescent film which is promising as a self-referenced temperature sensor.

Janus hollow spheres, with different compositions compartmentalized onto both interior and exterior surfaces of the same shell and P25 nanoparticles encapsulated in the cavities, are synthesized by the ultrasonic spray method to selectively enrich desired reagents in a confined environment for further reaction.

We have reported a new approach to fabricate mesoporous silica composite nanosheets by milling the corresponding hollow spheres. The mesoporous nanosheets are amphiphilic, and can be well dispersible both in water and oil, serving as particulate emulsifiers in o/w or w/o systems. The mesoporous silica can assist other functional materials, for example metal and carbon to be dispersible. An example is given to demonstrate the support of catalysts for a heterogeneous catalytic aerobic oxidation of benzyl alcohols by Pt/silica composite nanosheets.

In this work, an injectable composite hydrogel was synthesized via a unique way of crosslinking glycol chitosan (GC) with silica nano-particles (SiNP) through non-chemical interactions, and was then applied as a kind of wound dressing. Gelation was achieved through the incorporation of SiNPs with the GC segments in aqueous solution, therefore strictly confining the movement of the solubilized polymer chains. Rheology tests showed that the sol–gel transition and the moduli of the hydrogel were influenced by the composition of the two components, the size of the nano-particles and the conformation of the polymers. Using such a strategy, tissue adhesion properties of GC were well-preserved in the GC/SiNP hydrogel and therefore it gains gluey properties toward biological tissues as demonstrated through the adhesion of two pieces of mouse skin, obtaining a lap-shear stretching force of ca. 90 kPa. This characteristic, together with the injectability, allowed the hydrogel to be administrated directly on the wound site and to fill the wound area. Meanwhile, the hydrogel also works as a carrier of protein and cells. The in situ encapsulation of fibroblasts enabled the promising properties of the GC/SiNP hydrogel to be used for treating full-thickness skin defects in a mouse model, resulting in the favorable growth of hair follicles and microvessels, hence reducing the risk of scar formation.

Polymeric micelles of amphiphilic block copolymers have been studied for decades for their application as a targeting delivery agent of anti-tumor drugs. However, the targeting micelles may cause an immunological response because of the surface distributed ligands. In this work, mixed micelles were developed to improve the specificity of cancer cell uptake under tumor-acidic conditions. This was achieved by the co-assembly of an active targeting amphiphilic polymer, i.e. cyclic (Arg-Gly-Asp-D-Phe-Lys) c(RGDfK) functionalized poly(ethylene oxide)-b-poly(ε-caprolactone) (cRGD-PEO-b-PCL), and a pH sensitive drug conjugate, i.e. benzoic-imine linked PEGylated doxorubicin (PEG-DOX). Because the PEG-DOX is cleavable at the extracellular pH of a solid tumor, the characteristics of the mixed micelles turn from “stealthy” to cancer cell-affinitive due to the detachment of PEG from the micelle surface and hence allow the action of the c(RGDfK) in the cRGD-PEO-b-PCL with the cancer cell membrane. Besides, the mixed micelles exhibited the capacity for encapsulating hydrophobic drugs such as paclitaxel to form a combination formulation. Our results indicate that co-assembly is a facile but efficient strategy to coordinate the characteristics of each individual component and thus provide combinatorial functions to the delivery system.