Jiaoli Li

pH triggered injectable amphiphilic hydrogel containing doxorubicin and paclitaxel

Injectable hydrogel with hydrophobic microdomains for incorporating both hydrophilic and hydrophobic drugs, herein doxorubicin hydrochloride (DOX) and paclitaxel (PTX), was synthesized through dynamic bonding of glycol chitosan and benzaldehyde capped poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) via Schiffs reaction triggered by environmental pH. Rheology tests show that the inclusion of hydrophilic drug decreases the gelation time and gains more robust gel, while the addition of hydrophobic drug has opposite influences. Dual-drug release from the DOX+PTX loaded gels was observed and the release rate can be accelerated by decreasing the environmental pH from physiological (7.4) to weak acidic pH (6.8). In vivo investigation proved that the gels were able to diminish the amount of DOX in blood circulation and limit the DOX-induced cardiotoxicity. By intratumoral administration, the hydrogel-drug formulations resulted in efficient growth inhibition of subcutaneous tumor (B16F10) on C57LB/6 mouse model. The advantage of the current system for DOX+PTX combination therapy was demonstrated by a prolongation of survival time in comparison with the single drug therapy.

Post modification of perovskite sensitized solar cells by aluminum oxide for enhanced performance

The method of post-modification by aluminum oxide was successfully introduced into perovskite sensitized solar cells with a liquid electrolyte. Post-modification by Al2O3 could both protect the perovskite sensitizer from corrosion by electrolyte and effectively suppressed electron recombination. The UV-vis spectra revealed an enhanced absorption especially in the long wavelength range after modification. The XRD results showed a disappeared peak of PbI2, demonstrating that the modification could effectively protect the perovskite from dissolution in the electrolyte. Stability test showed that the remaining JSC improved from 10% to 50% at a given period of time. The EIS results and dark current curves illustrated that this modification increased the interface resistance in dark, confirming that the electron recombination process was effectively restrained. Finally, the corresponding efficiency was largely increased from 3.56 to 6.00% by 68%. The strategy using aluminium oxide to post-modify a perovskite sensitized solar cell was therefore proved to be a useful tool for the optimization of perovskite sensitized solar cells.

Polymer nanotubes toward gelating organic chemicals

Crosslinked polymer nanotubes are large scale synthesized. The method is based on fast cationic polymerization using immiscible initiator nanodroplets. Nanoporous network processed from the nanotubes is superhydrophobic, which can absorb all the tested organic chemicals forming robust gels. The nanotubes are promising in the collection of spilled organic chemicals, detoxification and water treatment.

Janus Nanodisc of Diblock Copolymers

Janus nanodiscs of diblock copolymers are prepared by stepwise disassembly of PS-b-P4VP disc-stacked particles. The Janus nanodiscs are uniform in thickness and regular in contour. By preferential growth of functional materials at the positively charged P4VP side, the composition, microstructure, and performance of the Janus nanodiscs are tunable.

Large scale synthesis of Janus submicron sized colloids by wet etching anisotropic ones

Janus colloids have inspired growing interests due to their diverse potential applications. Herein, we present a facile approach to fabricate Janus submicron sized colloids by the selective etching of anisotropic colloids. Size ratio, microstructure and composition are tunable. The method can be scaled up, which is the key to further exploit practical applications.

PEG-urokinase nanogels with enhanced stability and controllable bioactivity

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.

Fibril-shaped aggregates of doxorubicin with poly-L-lysine and its derivative

Complex formation between polymers and organic molecules is an interesting topic in polymer physics. Compared to the influence of small molecules on polymer assembly, there are fewer examples demonstrating the effect of polymers on the supramolecular structures formed by organic molecules. In this paper, we first prove that doxorubicin (DOX), a common anti-tumour drug, assembles into fibril-like aggregates in phosphate buffer (pH 7.4) and then show that the assembly of DOX was influenced by the complexation with an amphiphilic poly (amino acid) derivative, i.e. cholate-grafted poly-L-lysine (PLL-CA). With PLL-CA, the DOX fibrils converted to helix structured nano-spindles, whilst the presence of PLL led to minor change on the morphology of PLL/DOX complex compared to the DOX aggregates, which is attributed to the amplitude of intermolecular interactions. As a DNA intercalating agent, the aggregation of DOX on its biofunctionality was also investigated, showing that the formation of fibril assemblies was unfavourable for the cellular internalization of DOX and caused lower cytotoxicity to DOX resistance MCF-7 cells, whereas the polymer/DOX complexes gained an improved cell uptake on the MCF-7/ADR cell line due to an enhanced electrostatic interaction between the complexes and the cell membrane.

Oriented mesoporous TiO2 film as photoanode for dye-sensitized solar cells

Flexible bicontinuous mesostructured polymer/inorganic composite membranes was prepared by undertaking co-assembly of surfactants and inorganic sol–gel processes inside pores of a preformed porous polymer membrane. After burning off the organic component, the oriented mesoporous TiO2 film was obtained. The three dimensional porous structure was carefully investigated, and a DSSC was fabricated using the obtained TiO2 film as photoanode. The method of incorporating surfactant induced self-organizing sol–gel process and a certain nanoporous template was proved to be a useful technique to create different kinds of nano-/mesoporous structures.