Xiangjun Zhang

Biocompatible Reactive Oxygen Species (ROS)‐Responsive Nanoparticles as Superior Drug Delivery Vehicles

A novel reactive oxygen species (ROS)-responsive nanoplatform can be successfully manufactured from a ROS-triggerable β-cyclodextrin material. Extensive in vitro and in vivo studies validate that this nanoscaled system may serve as a new drug delivery vehicle with well-defined ROS-sensitivity and superior biocompatibility. This nanocarrier can be used for ROS-triggered transport of diverse therapeutics and imaging agents.

Reversion of multidrug resistance by a pH-responsive cyclodextrin-derived nanomedicine in drug resistant cancer cells.

Multidrug resistance (MDR) is one of the major problems responsible for inefficiency of cancer chemotherapy. Currently, there is still unmet demand for innovative strategies as well as effective and safe sensitizers to overcome MDR. In this study, we developed a nanosensitizer based on a pH-responsive nanoparticle (NP) derived from acetalated α-cyclodextrin (Ac-aCD). This pH-responsive NP could be effectively endocytosed by MDR cancer cells, and intracellularly transported by endolysosomal compartments. Ac-aCD NP was able to dramatically potentiate the activity of anticancer drugs including paclitaxel, docetaxel, cis-diamminedichloroplatinum, camptothecin, and doxorubicin. This sensitizing capability of Ac-aCD NP on MDR cells was resulted from the combined effects of decreased Pgp expression, attenuated Pgp ATPase activity, and the reduced intracellular ATP level. Ac-aCD NP exerted these diverse biological functions by intracellularly released α-cyclodextrin molecules, which were produced due to hydrolysis of Ac-aCD in acidic subcellular organelle. On the other hand, treatment with Ac-aCD NP showed no significant effects on the integrity of the plasma membrane, cytoskeleton, cell cycle, mitochondrial membrane potential, and apoptosis. These findings suggest that this pH-responsive NP has great potential for effective therapy of resistant cancers by combining with chemotherapeutic agents. It may also serve as a pharmacologically active nanocarrier for intracellular delivery of a plethora of antitumor drugs.

Multiple noncovalent interactions mediated one-pot therapeutic assemblies for the effective treatment of atherosclerosis

Atherosclerosis may cause life-threatening coronary artery disease, carotid artery disease, stroke, and peripheral vascular disease, while its effective therapy remains challenging thus far. With the aim of facilely constructing efficacious and translational oral delivery systems for an anti-atherosclerotic drug of rapamycin (RAP), an all-in-one approach was created. This strategy involves a carboxyl-bearing compound (serves as a guest molecule) mediated self-assembly of a structurally simple host polymer of poly(N-isopropylacrylamide) (PNIPAm). The formation of microspheres and highly efficient packaging of RAP could be simultaneously achieved by this host-guest self-assembly, affording cost-effective therapeutic assemblies with particularly robust drug loading capacity, desirable drug dissolution, relative manufacturing simplicity, good lyophilization-reconstitution character, and facile scalability. Besides these pharmaceutical characteristics superior over control microspheres based on poly(lactide-co-glycolide) or a enteric coating material, therapeutic RAP microspheres fabricated by this assembly approach had high oral bioavailability. More importantly, assembled RAP microspheres displayed significant therapeutic advantages upon treatment of atherosclerosis in an apolipoprotein E-deficient mouse model. In addition, a long-term treatment with either RAP-containing assemblies or the carrier material PNIPAm revealed a good safety profile in mice post oral delivery. Accordingly, RAP microspheres developed herein are promising and translational therapeutics for atherosclerotic diseases. This study also provides new insights into the design of effective carrier materials for various lipophilic therapeutics.

A systematic evaluation of the biocompatibility of cucurbit[7]uril in mice

As one of the most water-soluble members in the macrocyclic cucurbit[n]uril (CB[n]) family, CB[7] has attracted increasing attention in pharmaceutical and biomedical fields. Despite extensive studies regarding the potential use of CB[7] for biomedical applications, its full safety and toxicity profile in a clinically relevant model is still lacking. Herein we report the full biocompatibility profile of CB[7], administered orally, peritoneally or intravenously in mice, respectively. Body-weight changes showed no significant differences among various groups of mice after they were administered with CB[7] at a single dose of 5 g/kg orally, 500 mg/kg peritoneally and 150 mg/kg intravenously, respectively. Hematology tests, as well as hepatic and renal function biochemical markers tests, of the blood collected from these mice sacrificed 21 days after CB[7] administration all exhibited normal ranges of values that were comparable with those of the control group. Moreover, histopathological analysis on the sections of major organs (including the heart, liver, spleen, lungs and kidneys) and gastrointestinal tissues revealed no detectable injuries and inflammatory cells infiltration. Taken together, these results suggest an excellent biocompatibility profile of CB[7] in mice, which provide important foundations for further investigations and even clinical applications of CB[7] in biomedical areas.