Increasing the biocompatibility of graphene-based hybrid nanostructures with glycopolymer.

Hybrid nanostructures decorated with glycopolymers are appropriate for biomedical applications. In this paper, the results are obtained from nanographene (NG) decorated with glycoblock copolymer to increase their potential in use in therapies and in examining lectin interactions. A pyren-1-ylmethyl 4-cyano-4-((phenylcarbonothioyl)thio)pentanoate (CPADB-py) chain transfer agent was used in the synthesis of methyl methacrylate glycoblock copolymers (P2 and P3) by reversible addition-fragmentation chain transfer (RAFT) polymerization to adhere the polymer to the nanographene surface. Hybrid nanographenes (NG-1 and NG-2) were obtained by the non-covalent interaction of deprotected P2 and P3 with different fructopyranose groups (3-O-methacryloyl-1,2:4,5-di-O-isopropylidene-ß-D-fructopyranose and 1-O-methacryloyl-2,3:4,5-di-O-isopropylidene-ß-D-fructopyranose) in their backbones. Images obtained from transmission electron microscopy (TEM) of NG-1 and NG-2 show that glycoblock copolymer coating was performed homogeneously. Moreover, thermal gravimetric analysis (TGA) also confirmed a glycoblock copolymer coating of NG-1 and NG-2 by weight loss of 41% and 31%, respectively. In the last step of the study, the binding ability of glycoblock copolymers (P2-hyd and P3-hyd) with concanavalin A (ConA) lectin was investigated by a turbidimetric assay. Promising results were obtained from P3-hyd for the ConA interactions. Hence, this study may open a new avenue in the design of new multifunctional glyconanomaterials that show favorable binding properties with lectins.

Phthalocyanine-Conjugated Glyconanoparticles for Chemo-photodynamic Combination Therapy.

Combination cancer therapy based on multifunctional nanomaterials has attracted great attention. The present work focuses on the preparation of the glycopolymeric nanoparticle, which contains a photosensitizer (zinc(II)phthalocyanine, ZnPc) and an anticancer drug (Doxorubicin, Dox). First, a novel mono azide-functional ZnPc-N3 with seven hydrophilic ethylene oxide chains was synthesized. Next, ZnPc alone or together with Dox bearing glycopolymers was synthesized via the RAFT polymerization method and then self-assembled into glyconanoparticles (GNPs) with narrow particle size distribution. Then the evaluation of the biological activity of GNPs (GNPs-ZnPc and GNPs-ZnPc/Dox) for dual photodynamic therapy (PDT) and chemotherapy against human breast cancer cells was investigated. The constructed GNPs were identified via general characterization methods, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). The prepared GNPs-ZnPc/Dox demonstrated remarkable photophysical and photochemical properties, involving good colloidal stability in biological conditions, pH-responsive drug release, and the capacity to generate singlet oxygen under light irradiation. The outer layer of nanoparticles covered by fructose sugar moieties achieves a targeted cancer therapy owing to GLUT5 (a well-known fructose transporter) overexpression toward breast cancer cells. In vitro experiments were then performed to evaluate the chemo/phototoxicity, cellular uptake, and anticancer efficacy of GNPs-ZnPc/Dox. In comparison with free Dox, human breast cancer cells treated with GNPs-ZnPc/Dox exhibited a higher cellular internalization via GLUT5 targeting. In particular, the GNPs-ZnPc/Dox nanoplatform revealed an excellent synergistic anticancer activity in comparison with free ZnPc-N3 and free Dox, representing a novel and promising chemo-photodynamic combination therapeutic methodology to improve therapeutic efficacy.

Glycopolymer decorated multiwalled carbon nanotubes for dual targeted breast cancer therapy.

Carbon-based nanomaterials (CNMs) have attracted great attention in biomedical applications such as cancer imaging and therapy. CNMs, which are currently used in a wide range of applications, suffer from drawbacks of toxicity and low biocompatibility. Either noncovalent or covalent functionalization of CNMs with hydrophilic and biocompatible polymers which help to block hydrophobic interactivity between CNMs and cells can greatly increase their biocompatibility by eliminating their probable toxicity towards living organisms. In this report, we present a comparison of both noncovalent and covalent functionalization approaches in order to introduce a biocompatible glycoblock copolymer onto multi-walled carbon nanotubes (CNTs) in order to enhance their potential in therapies. An anticancer drug (doxorubicin, Dox) was conjugated with two different end functionalized poly(1-O-methacryloyl-ß-d-fructopyranose-b-(2-methacryloxyethoxy))benzaldehyde glycoblock copolymers, which were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, by either noncovalent or covalent tethering. CNTs were coated separately with the synthesized drug-conjugated glycoblock copolymers and folic acid (FA) to obtain an efficient drug delivery platform for dual-targeting of glucose transporter protein (GLUT5) and folic acid receptors (FR) in breast cancer. A library of synthesized monomers, polymers and prepared glycoblock copolymer coated CNTs (hybrid-CNTs) using both approaches were comprehensively characterized by various techniques. Transmission electron microscopy measurements showed the homogeneous, smooth morphology of the prepared Dox-conjugated glycoblock copolymer coating of CNTs and confocal laser scanning microscopy images displayed successful cellular internalization of hybrid-CNTs in the MCF-7 and MDA-MB-231 human breast cancer cell lines. This research demonstrates the potential of hybrid-CNTs as a biocompatible drug delivery system as well as in vitro use of Dox-conjugated vehicles for dual receptor mediated breast cancer therapy.

Glyconanoparticles for Targeted Tumor Therapy of Platinum Anticancer Drug.

An important requirement to decrease the side effects of chemotherapy drugs is to develop nanocarriers with precise biological functions. In this work, a set of glyconanoparticles was prepared via self-assembly of amphiphilic glycoblock copolymers for the targeted delivery of a hydrophobic chemotherapy drug. Well-defined glycoblock copolymers that consist of 1,1-di-tert-butyl 3-(2-(metyloyloxy)ethyl)-butane-1,1,3-tricarboxylate (MAETC) together with three different protected-sugar moieties (ß-d-glucopyranoside, ß-d-mannopyranoside, and ß-l-fucopyranoside) were synthesized by using reversible addition-fragmentation chain-transfer polymerization. Copolymers were deprotected and conjugated with the cis-dichlorodiammineplatinum(II) (cis-Pt) anticancer drug. Dynamic light scattering and transmission electron microscopy measurements revealed that cis-Pt-conjugated glyconanoparticles were sufficiently stable under physiological conditions and had diameters of approximately 100 nm with considerably narrow size distributions. They were intracellularly taken up by the breast cancer (MCF-7 and MDA-MB-231), prostate cancer (PC3), renal cancer (769-P), and Chinese hamster ovary cell lines. The PC3 and 769-P cell lines showed a high preference for the glycosylated nanoparticles. Glycoblock copolymers were found nontoxic but showed high cytotoxicity and increased efficacy after conjugation with the cis-Pt anticancer drug. Moreover, in vitro cytotoxicity assays in cancer cell lines demonstrate that cis-Pt-loaded glycopolymer-based nanoparticles have higher cytotoxicity than free cis-Pt. Overall, our results suggest that glyconanoparticles have a great potential to be used as an effective cis-Pt drug carrier for targeted cancer therapy.