Well-defined single polymer nanoparticles for the antibody-targeted delivery of chemotherapeutic agents

Radiant star nanoparticle prodrugs for the treatment of intracellular alveolar infections

Radiant star nanoparticle prodrugs were synthesized in a two-step process by first homopolymerizing RAFT transmers followed by copolymerization from the hyperbranched polymer core.

Stimuli-Sensitive Biodegradable and Amphiphilic Block Copolymer-Gemcitabine Conjugates Self-Assemble into a Nanoscale Vehicle for Cancer Therapy

The availability and the stability of current anticancer agents, particularly water-insoluble drugs, are still far from satisfactory. A widely used anticancer drug, gemcitabine (GEM), is so poorly stable in circulation that some polymeric drug-delivery systems have been under development for some time to improve its therapeutic index. Herein, we designed, prepared, and characterized a biodegradable amphiphilic block N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-GEM conjugate-based nanoscale and stimuli-sensitive drug-delivery vehicle. An enzyme-sensitive oligopeptide sequence glycylphenylalanylleucylglycine (GFLG) was introduced to the main chain with hydrophilic and hydrophobic blocks via the reversible addition-fragmentation chain transfer (RAFT) polymerization. Likewise, GEM was conjugated to the copolymer via the enzyme-sensitive peptide GFLG, producing a high molecular weight (MW) product (90 kDa) that can be degraded into smaller MW segments (<50 kDa), and ensuring potential rapid site-specific release and stability in vivo. The amphiphilic copolymer-GEM conjugate can self-assemble into compact nanoparticles. NIR fluorescent images demonstrated that the conjugate-based nanoparticles could accumulate and be retained within tumors, resulting in significant increased antitumor efficacy compared to free GEM. The conjugate was not toxic to organs of the mice as measured by body weight reductions and histological analysis. In summary, this biodegradable amphiphilic block HPMA copolymer-gemcitabine conjugate has the potential to be a stimuli-sensitive and nanoscale drug-delivery vehicle.

Aqueous RAFT at pH zero: enabling controlled polymerization of unprotected acyl hydrazide methacrylamides

A first example of controlled radical polymerization of monomers containing unprotected acyl hydrazide pendent groups was demonstrated using aqueous RAFT polymerization at pH = 0.

Chemotherapeutic copolymers prepared via the RAFT polymerization of prodrug monomers

Reversible addition–fragmentation chain transfer (RAFT) polymerization was employed to prepare prodrug polymer carrier systems with the chemotherapeutic agent camptothecin (Cam) and the kinase inhibitor dasatinib (Dt).

RAFT polymerization of ciprofloxacin prodrug monomers for the controlled intracellular delivery of antibiotics

Prodrug monomers derived from the antibiotic ciprofloxacin were synthesized with phenolic or aliphatic esters linking the drug to a polymerizable methacrylate group.

Polymer nanostructures synthesized by controlled living polymerization for tumor-targeted drug delivery

The development of drug delivery systems based on well-defined polymer nanostructures could lead to significant improvements in the treatment of cancer. The design of these therapeutic nanosystems must account for numerous systemic and circulation obstacles as well as the specific pathophysiology of the tumor. Nanoparticle size and surface charge must also be carefully selected in order to maintain long circulation times, allow tumor penetration, and avoid clearance by the reticuloendothelial system (RES). Targeting ligands such as vitamins, peptides, and antibodies can improve the accumulation of nanoparticle-based therapies in tumor tissue but must be optimized to allow for intratumoral penetration. In this review, we will highlight factors influencing the design of nanoparticle therapies as well as the development of modern controlled "living" polymerization techniques (e.g. ATRP, RAFT, ROMP) that are leading to the creation of sophisticated new polymer architectures with discrete spatially-defined functional modules. These innovative materials (e.g. star polymers, polymer brushes, macrocyclic polymers, and hyperbranched polymers) combine many of the desirable properties of traditional nanoparticle therapies while substantially reducing or eliminating the need for complex formulations.

ATRP Synthesis of Sunflower Polymers using Cyclic Multimacroinitiators

Polymers with advanced architectures can now be readily and reproducibly synthesized using controlled living polymerization. These materials are attractive as potential drug carriers due to their tunable size, versatile methods of drug incorporation and release, and ease of functionalization with targeting ligands. In this work, we report the design and development of macrocyclic brush, or "sunflower," polymers, synthesized by controlled radical polymerization of hydrophilic "petals" from a cyclic multimacroinitiator "core." These nanostructures can be synthesized with low polydispersity and controlled sizes depending on polymerization time. We further demonstrate that folate-functionalized sunflower polymers facilitate receptor-mediated uptake into cancer cells. These materials therefore show potential as drug carriers for anti-cancer therapies.

Multifunctional ATRP based pH responsive polymeric nanoparticles for improved doxorubicin chemotherapy in breast cancer by proton sponge effect/endo-lysosomal escape

Folic acid and trastuzumab functionalized pH responsive polymeric nanoparticles for intracellular doxorubicin delivery in breast cancer.

Pd-complex driven formation of single-chain nanoparticles

The preparation and in-depth characterization of well-defined, palladium(ii) crosslinked single-chain nanoparticles (Pd-SCNPs) is reported. In addition, a novel procedure for interpreting the SEC chromatograms of SCNPs by log-normal distribution (LND) simulations is introduced.