Xingang Guan

Integrating Oxaliplatin with Highly Luminescent Carbon Dots: An Unprecedented Theranostic Agent for Personalized Medicine

A theranostic nanomedicine (CD-Oxa) is synthesized by means of the condensation reaction between the amino groups on the surface of fluorescent carbon dots (CDs) and the carboxyl group of the oxaliplatin derivative Oxa(IV)-COOH. CD-Oxa, which integrates the optical properties of CDs and the anticancer function of oxaliplatin, could be used for simultaneous drug delivery and fluorescent tracking.

One-Step Synthesis of Nanoscale Zeolitic Imidazolate Frameworks with High Curcumin Loading for Treatment of Cervical Cancer

A straightforward nanoprecipitating method was developed to prepare water dispersible curcumin (CCM)-loaded nanoscale zeolitic imidazolate framework-8 (CCM@NZIF-8) nanoparticles (NPs). The as-synthesized CCM@NZIF-8 NPs possess high drug encapsulation efficiency (88.2%), good chemical stability and fast drug release in tumor acidic microenvironments. Confocal laser scanning microscopy and cytotoxicity experiments reveal that NZIF-8 based nanocarriers promote the cellular uptake of CCM and result in higher cytotoxicity of CCM@NZIF-8 than that of free CCM toward HeLa cells. The in vivo anticancer experiments indicate that CCM@NZIF-8 NPs exhibit much higher antitumor efficacy than free CCM. This work highlights the potential of using nanoscale metal organic framworks (NMOFs) as a simple and stable platform for developing a highly efficient drug delivery system in cancer treatment.

Near-Infrared Emitting Fluorescent BODIPY Nanovesicles for in Vivo Molecular Imaging and Drug Delivery

Near-infrared fluorescent nanovesicles were prepared by self-assembly of block copolymer hydrophilic poly(ethylene glycol) boron-dipyrromethenes in aqueous solution. The fluorescence enhancement induced by dissociation of nanovesicles could be used as a smart imaging and diagnostic tool. This nanovesicle could encapsulate the antitumor drug, and provide a powerful platform for imaging-guided tumor-specific drug delivery and therapy.

Reduction-sensitive amphiphilic copolymers made via multi-component Passerini reaction for drug delivery.

One-step synthesis of amphiphilic polymers containing disulfide bond within the hydrophobic backbone was demonstrated via multi-component Passerini reaction. The obtained polymer was self-assembled into micelles in aqueous solution. Curcumin (CUR), an effective and safe anticancer agent, which was limited by its water insolubility and poor bioavailability, was loaded into the micelles as a model drug. The nanoscale polymeric micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Faster intracellular CUR release was observed by confocal laser scanning microscopy (CLSM) in the HeLa cells pretreated with GSH than in the unpretreated ones. Micelles also loaded with NH2-BODIPY which was almost non-fluorescent and gave strong enhanced fluorescence under acid conditions. The phenomenon of the stronger enhanced fluorescence in the pretreated HeLa cells showed further that the obtained polymer was reduction-sensitive. In vitro MTT assays showed that the micelles were biocompatible and CUR-loaded micelles had higher cellular proliferation inhibition in contrast to free CUR toward HeLa cells. These results highlight the potential of using multi-component Passerini reaction to make functional copolymers as smart nanocarriers for drug delivery.

A nanosized {Ag@Ag12} "molecular windmill" templated by polyoxometalates anions.

Reaction of multidentate 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole (L) ligand with Ag(I) ions in the existence of H3PW12O40 as anionic template under hydrothermal conditions results in tridecanuclear silver cluster-polyoxometalates hybrid: {Ag13L12}{PW12O40}4·30H2O (1). X-ray single crystal diffraction analysis indicates that the main structural feature of 1 is a nanosized molecular windmill-shaped polynuclear Ag cluster with intriguing {M@M12}-type cuboctahedral topology. The as-synthesized compound exhibits effective photocatalytic activity in the photodegradation of Rhodamine-B (RhB) and antibacterial activity against Escherichia coli, respectively.

Cyclic RGD targeting nanoparticles with pH sensitive polymer-drug conjugates for effective treatment of melanoma

It is highly desirable to design and develop multifunctional nanoparticles for improving specificity, tumor accumulation and therapeutic efficacy. A strategy of combining active targeting with tumor microenvironmental response in one polymeric drug delivery system was developed via assembling a c(RGDfK)-linked copolymer and a pH sensitive polymer–epirubicin conjugate in aqueous solution. These hybrid micelles with a diameter of less than 100 nm showed pH sensitive drug release behaviours in vitro, which could be used for assisting tumor targeting and drug delivery. Confocal laser scanning microscopy and flow cytometry results indicated that they can enhance the endocytosis by B16F10 cells. Moreover, the hybrid micelles displayed a synergistic effect and led to increased cytotoxicity in vitro and enhanced antitumor efficacy in vivo.

cRGD targeted and charge conversion-controlled release micelles for doxorubicin delivery

Efficiently and selectively delivering chemotherapeutic agents to tumours still remains a challenge for the development of nanocarriers. In this study, polymer micelles based on cRGD targeting and pH-sensitive surface charge-switching were successfully prepared and used for doxorubicin (Dox) delivery. This nanoscale polymeric micelle indicated a high drug encapsulation efficiency of 90% and slightly negative charge. Drug release experiments showed a pH-enhanced release profile in PBS, which resulted from surface charge-switching by imidazole. Confocal laser scanning microscopy and flow cytometry experiments indicated that combining the capability of an RGD target and pH-sensitive charge-switching significantly enhanced the cellular uptake of B16F10 cells overexpressing αvβ3 integrins. An MTT assay also showed that our hybrid RGD-decorated micelles were much more cytotoxic to B16F10 cells than undecorated micelles. These results suggest the potential application of a cRGD target and pH-sensitive surface charge-switching polymeric micelles in the treatment of αvβ3 integrin-overexpressing cancers.

Rational design and synthesis of covalent organic polymers with hollow structure and excellent antibacterial efficacy

A covalent organic polymer with hollow structure (COP-H) has been synthesized via Sonogashira coupling from the precursors containing positive charge. The formation of COP-H was confirmed by FTIR, solid-state NMR, SEM and TEM. COP-H showed excellent anti-microbial activity because of the cationic charge on the surface of COP-H.

Cyclic RGD targeting cisplatin micelles for near-infrared imaging-guided chemotherapy

Nowadays imaging-guided chemotherapy is of great importance for developing highly efficient nanomedicines for cancer therapy. However, drug accumulation and release in vivo cannot be tracked in most studies due to the imaging moiety. In this study, near-infrared (NIR) dyes, cisplatin and dextran were used to prepare an imaging-guided chemotherapy drug with a cyclic peptide arginine-glycine-aspartic acid (RGD) targeting property for the treatment of breast cancer. Confocal laser scanning microscopy (CLSM) analysis indicated that the cisplatin-loaded micelles with cRGD decoration were quickly taken up by breast cancers cells in vitro according to the fluorescence of the NIR dye. More importantly, in vivo bioluminescence imaging analysis indicated that the drug-loaded micelles were preferentially distributed in the tumor regions of tumor-bearing mice. Furthermore, combining RGD targeting, in vivo imaging and therapeutic properties, this nanomedicine was suggested to have a good anti-tumor activity in vivo. Our study highlights the potential of combining active targeting and NIR fluorescence imaging in one drug delivery system for cancer diagnosis and therapy.

EGFP-Based Protein Nanoparticles with Cell-Penetrating Peptide for Efficient siRNA Delivery

Development of an innovative nucleic acid nanocarriers still represents a challenge. In this study, we develop a protein nanoparticle (H6-TatEGFP) and examine its siRNA condensing activity. Gel retardation assay show that protein nanoparticle can condense siRNA into stable nanoparticle/siRNA complexes. UsingCy3-labelled siRNA, we also evaluate siRNA transport characteristic of protein nanoparticles in tumor cells, the results indicate that H6-TatEGFP nanoparticle may be a potential nanocarrier for siRNA in tumor cells.