A novel dual-pH sensitive charge-reversal strategy is designed to deliver antitumor drugs targeting to tumor cells and to further promote the nuclei internalization by a stepwise response to the mildly acidic extracellular pH (≈6.5) of a tumor and endo/lysosome pH (≈5.0). Poly(L-lysine)-block-poly(L-leucine) diblock copolymer is synthesized and the lysine amino residues are amidated by 2,3-dimethylmaleic anhydride to form β-carboxylic amide, making the polypeptides self-assemble into negatively charged micelles. The amide can be hydrolyzed when exposed to the mildly acidic tumor extracellular environment, which makes the micelles switch to positively charged and they are then readily internalized by tumor cells. A nuclear targeting Tat peptide is further conjugated to the polypeptide via a click reaction. The Tat is amidated by succinyl chloride to mask its positive charge and cell-penetrating function and thus to inhibit nonspecific cellular uptake. After the nanoparticles are internalized into the more acidic intracellular endo/lysosomes, the Tat succinyl amide is hydrolyzed to reactivate the Tat nuclear targeting function, promoting nanoparticle delivery into cell nuclei. This polypeptide nanocarrier facilitates tumor targeting and nuclear delivery simultaneously by simply modifying the lysine amino residues of polylysine and Tat into two different pH-sensitive β-carboxylic amides.

A novel pH- and redox- dual-responsive tumor-triggered targeting mesoporous silica nanoparticle (TTTMSN) is designed as a drug carrier. The peptide RGDFFFFC is anchored on the surface of mesoporous silica nanoparticles via disulfide bonds, which are redox-responsive, as a gatekeeper as well as a tumor-targeting ligand. PEGylated technology is employed to protect the anchored peptide ligands. The peptide and monomethoxypolyethylene glycol (MPEG) with benzoic-imine bond, which is pH-sensitive, are then connected via "click" chemistry to obtain TTTMSN. In vitro cell research demonstrates that the targeting property of TTTMSN is switched off in normal tissues with neutral pH condition, and switched on in tumor tissues with acidic pH condition after removing the MPEG segment by hydrolysis of benzoic-imine bond under acidic conditions. After deshielding of the MPEG segment, the drug-loaded nanoparticles are easily taken up by tumor cells due to the exposed peptide targeting ligand, and subsequently the redox signal glutathione in tumor cells induces rapid drug release intracellularly after the cleavage of disulfide bond. This novel intelligent TTTMSN drug delivery system has great potential for cancer therapy.

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A new design strategy for the development of fluorescent turn-on chemodosimeters toward OCl(-) was proposed by the removal, but not the general inhibition, of the C=N isomerization. Accordingly, Flu-1 was prepared, which, as shown in the fluorescent picture, exhibited the off-on response for OCl(-), sensitively and selectively.

It is a tough task in clinic to remove and refuel the dressing. Therefore, we have explored a bioinspired dressing which can be swiftly detached from wound beds and rapidly strengthened during the dressing change procedures.

Supramolecular microcapsules (SMCs) with the drug-loaded wall layers for pH-controlled drug delivery were designed and prepared. By using layer-by-layer (LbL) technique, the SMCs were constructed based on the self-assembly between polyaldenhyde dextran-graft-adamantane (PAD-g-AD) and carboxymethyl dextran-graft-β-CD (CMD-g-β-CD) on CaCO(3) particles via host-guest interaction. Simultaneously, adamantine-modified doxorubicin (AD-Dox) was also loaded on the LbL wall via host-guest interaction. The in vitro drug release study was carried out at different pHs. Because the AD groups were linked with PAD (PAD-g-AD) or Dox (AD-Dox) by pH-cleavable hydrazone bonds, AD moieties can be removed under the weak acidic condition, leading to destruction of SMCs and release of Dox. The pH-controlled drug release can enhance the uptake by tumor cells and thus achieve improved cancer therapy efficiency.

Carrier‐free nanoparticles with high drug loading have attracted increasing attention; however, in situ on‐demand drug release remains a challenge. Here, a novel near‐infrared (NIR) laser‐induced blasting carrier‐free nanodrug delivery system is designed and fabricated by coating doxorubicin (DOX) nanoparticles (DNPs) with a polydopamine film (PDA) that would prolong the blood circulation time of DNPs and avoid the preleakage of the DOX during blood circulation. Meanwhile, the NH4HCO3 is introduced to trigger in situ “bomb‐like” release of DOX for the production of carbon dioxide (CO2) and ammonia (NH3) gases driven by NIR irradiated photothermal effect of PDA. Both in vitro and in vivo studies demonstrate that the carrier‐free nanovectors with high drug loading efficiency (85.8%) prolong tumor accumulation, enhance chemotherapy, achieve the synergistic treatment of chemotherapy and photothermal treatment, and do not induce any foreign‐body reaction over a three‐week implantation. Hence, the delicate design opens a self‐assembly path to develop PDA‐based NIR‐responsive multifunctional carrier‐free nanoparticles for tumor therapy.