In situ nanofabrication of hybrid PEG-dendritic-inorganic nanoparticles and preliminary evaluation of their biocompatibility

Modular Synthesis of PEG-Dendritic Block Copolymers by Thermal Azide-Alkyne Cycloaddition with Internal Alkynes and Evaluation of their Self-Assembly for Drug Delivery Applications

Linear-dendritic block copolymers assemble in solution due to differences in the solubility or charge properties of the blocks. The monodispersity and multivalency of the dendritic block provide unparalleled control for the design of drug delivery systems when incorporating poly(ethylene glycol) (PEG) as a linear block. An accelerated synthesis of PEG-dendritic block copolymers based on the click and green chemistry pillars is described. The tandem composed of the thermal azide-alkyne cycloaddition with internal alkynes and azide substitution is revealed as a flexible, reliable, atom-economical, and user-friendly strategy for the synthesis and functionalization of biodegradable (polyester) PEG-dendritic block copolymers. The high orthogonality of the sequence has been exploited for the preparation of heterolayered copolymers with terminal alkenes and alkynes, which are amenable for subsequent functionalization by thiol-ene and thiol-yne click reactions. Copolymers with tunable solubility and charge were so obtained for the preparation of various types of nanoassemblies with promising applications in drug delivery.

Polyglutamic acid-based crosslinked doxorubicin nanogels as an anti-metastatic treatment for triple negative breast cancer

Treatment of triple negative breast cancer (TNBC)-associated metastasis represents an unmet clinical need, and we lack effective therapeutics for a disease that exhibits high relapse rates and associates with poor patient outcomes. Advanced nanosized drug delivery systems may enhance the efficacy of first-line chemotherapeutics by altering drug pharmacokinetics and enhancing tumor/metastasis targeting to significantly improve efficacy and safety. Herein, we propose the application of injectable poly-amino acid-based nanogels (NGs) as a versatile hydrophilic drug delivery platform for the treatment of TNBC lung metastasis. We prepared biocompatible and biodegradable cross-linked NGs from polyglutamic acid (PGA) loaded with the chemotherapeutic agent doxorubicin (DOX). Our optimized synthetic procedures generated NGs of ~100 nm in size and 25 wt% drug loading content that became rapidly internalized in TNBC cell lines and displayed IC50 values comparable to the free form of DOX. Importantly, PGA-DOX NGs significantly inhibited lung metastases and almost completely suppressed lymph node metastases in a spontaneously metastatic orthotopic mouse TNBC model. Overall, our newly developed PGA-DOX NGs represent a potentially effective therapeutic strategy for the treatment of TNBC metastases.

Polysaccharides meet dendrimers to fine-tune the stability and release properties of polyion complex micelles

Dendritic-polysaccharide PIC micelles represent promising delivery systems where dendritic rigidity and polysaccharide stiffness synchronize to determine the stability of the micelles, their kinetics of intracellular drug release, and cytotoxicity.

Gold-loaded microspheres via carbosilane-thioether dendrimers as stabilizers and their performance in layer-controllable photonic crystals

Gold nanoparticle (Au NP) incorporated photonic crystals (PCs) have been extensively studied due to the intricate interplay between the surface plasmon resonance of Au NPs and the periodic nanostructure of PCs. Herein, we successfully synthesized Au NP decorated poly(styrene-co-(generation 3 carbosilane-thioether vinyl-terminated dendrimer)) (P(st-co-G3Vi)) microspheres via in situ reduction of Au ions based on the strong coordination between the Au ions and the sulfur atom in G3Vi dendrimers. These composite Au-doped microspheres demonstrate a bumpy surface topography, which gives rise to a higher hydrophobicity and could effectively suppress the formation of an ubiquitous coffee-ring during the drying process of a colloidal suspension. More importantly, layer-controllable PCs were constructed with Au-doped microspheres by combining the Langmuir-Blodgett method with a layer-by-layer stacking strategy. By manipulating the stacking layers and diameters of microspheres, multifarious PCs with different photonic band gaps and reflection intensities were obtained, which can serve as an effective substrate for amplified quantum dot fluorescence. Further investigation reveals that fluorescence could be significantly pronounced by five-layer PCs. This work offers a facile and reproducible strategy to prepare Au NP incorporated PCs by in situ synthesis of Au NPs within dendrimer-functionalized microspheres, resulting in an enhancement of quantum dot fluorescence, which will lead to promising applications in energy-saving optoelectronic devices.

Biodegradable PEG–dendritic block copolymers: synthesis and biofunctionality assessment as vectors of siRNA

New hybrid-biodegradable PEG–dendritic block copolymers as versatile delivery vectors for biomedical applications. Here, their biofunctionality as siRNA vectors is presented.

Host-guest interaction induced supramolecular amphiphilic star architecture and uniform nanovesicle formation for anticancer drug delivery

A star polymer of poly[(R,S)-3-hydroxybutyrate] (PHB) with adamantyl end-terminals extended from an α-cyclodextrin (α-CD) core is designed. It subsequently self-assembles to form controllable and uniform nanovesicles induced by host-guest interactions between heptakis(2,6-di-O-methyl)-β-CD and the adamantyl ends. The nanovesicles are suitable for loading and intracellular delivery of the anticancer drug doxorubicin.