pH-Activatable Charge-Reversal Polymer-Based Nanocarriers for Targeted Delivery of Antihepatoma Compound.

Chemotherapy is one of the available cancer treatments which has been successfully employed to prolong the survival of cancer patients. However, it remains a major challenge to develop effective chemotherapeutic agents by reducing off-target toxicity, improving bioavailability, and effectively prolonging blood circulation. The pH profile of tumor cells is abnormal to that of normal cells, making it a potential breakthrough for designing effective chemotherapeutic drug agents. Here, the pH-activatable charge-reversal supramolecular nanocarriers, named MI7-ß-CD/SA NPs, were prepared through a simple and "green" constructive process. MI7-ß-CD/SA NPs possess both pH-induced charge-reversal and disassembly properties that were exploited to investigate the loading, delivery, and pH-responsive controlled release of the antitumor compound celastrol (CSL). CSL@MI7-ß-CD/SA NPs displayed low hemolysis, good biocompatibility, and targeted uptake. Furthermore, CSL@MI7-ß-CD/SA NPs exhibited superior apoptosis rates against SMMC-7721 cell lines compared with CSL, when CSL@MI7-ß-CD/SA NPs and CSL were administered at a mass concentration of 5.0 µg/mL, i.e., the CSL content in CSL@MI7-ß-CD/SA NPs was relatively lower than that of intact CSL. We expected that MI7-ß-CD/SA NPs featuring pH-triggered charge reversal could offer a promising controlled release strategy that would then facilitate the clinical conversion of antitumor drugs.

Triblock polyphiles through click chemistry: self-assembled thermotropic cubic phases formed by micellar and monolayer vesicular aggregates.

Three series of triblock polyphiles consisting of a rigid 4-phenyl-1,2,3-triazole or 1,4-diphenyl-1,2,3-triazole core with three lipophilic and flexible alkoxyl chains at one end and a polar glycerol group at the opposite end were synthesized by copper-catalyzed azide-alkyne click reactions. Their mesophase behavior was studied by polarizing optical microscopy, differential scanning calorimetry, and XRD. Depending on alkyl chain length and core length, a transition from hexagonal columnar to Pm3n-type cubic phases was observed. In the cubic phases, the molecules are organized as spherical objects. Remarkably, compounds with a longer core unit have a higher tendency to form these cubic phases, and their stability is strongly enhanced over those of the compounds with a shorter core, despite longer cores having a smaller cone angle and therefore being expected to disfavor the formation of spherical objects. There is a large difference in the number of molecules involved in the spherical aggregates formed by compounds with long and short cores. Whereas the aggregates in the cubic phases of the compounds with short rod units are small and could be regarded as micellar, the long-core compounds form much larger aggregates which are regarded as a kind of monolayer vesicular aggregate.