Supramolecular nanocarrier of anionic dendrimer porphyrins with cationic block copolymers modified with polyethylene glycol to enhance intracellular photodynamic efficacy

Polymer Therapeutics: Concepts and Applications

Polymer therapeutics encompass polymer-protein conjugates, drug-polymer conjugates, and supramolecular drug-delivery systems. Numerous polymer-protein conjugates with improved stability and pharmacokinetic properties have been developed, for example, by anchoring enzymes or biologically relevant proteins to polyethylene glycol components (PEGylation). Several polymer-protein conjugates have received market approval, for example the PEGylated form of adenosine deaminase. Coupling low-molecular-weight anticancer drugs to high-molecular-weight polymers through a cleavable linker is an effective method for improving the therapeutic index of clinically established agents, and the first candidates have been evaluated in clinical trials, including, N-(2-hydroxypropyl)methacrylamide conjugates of doxorubicin, camptothecin, paclitaxel, and platinum(II) complexes. Another class of polymer therapeutics are drug-delivery systems based on well-defined multivalent and dendritic polymers. These include polyanionic polymers for the inhibition of virus attachment, polycationic complexes with DNA or RNA (polyplexes), and dendritic core-shell architectures for the encapsulation of drugs. In this Review an overview of polymer therapeutics is presented with a focus on concepts and examples that characterize the salient features of the drug-delivery systems.

New drug delivery for corneal neovascularization using polyion complex micelles

PURPOSE

To introduce photodynamic therapy (PDT) for corneal neovascularization (NV) by polyion complex (PIC) micelles, a novel drug delivery system.

METHODS AND RESULTS

Development of specific drug delivery systems to corneal NV sites is an important part of next-generation photodynamic therapy. Nanocarriers consisting of PIC micelles bound by polyethylene glycol (PEG) shell exhibit good stability, high drug-loading capacity, and excellent potential for controlled drug release. Encapsulation of the photosensitizer dendrimer porphyrin (DP) into PIC micelles (DP-micelles) conveys adequate stability and increased photocytotoxicity without compromising photophysical properties of DP stability. We assessed the accumulation of DP-micelles and observed that the DP-micelles were incorporated into the corneal NV area.

CONCLUSIONS

PIC micelles possess attractive features of selective accumulation at the corneal NV site. PDT using DP-micelles appears to be effective and safe for the treatment of corneal NV.

Nanotechnology-based photodynamic therapy for neovascular disease using a supramolecular nanocarrier loaded with a dendritic photosensitizer

Photodynamic therapy (PDT) for exudative age-related macular degeneration (AMD) was evaluated using a supramolecular nanomedical device, that is, a novel dendritic photosensitizer (DP) encapsulated by a polymeric micelle formulation. The characteristic dendritic structure of the DP prevents aggregation of its core sensitizer, thereby inducing a highly effective photochemical reaction. With its highly selective accumulation on choroidal neovascularization (CNV) lesions, this treatment resulted in a remarkably efficacious CNV occlusion with minimal unfavorable phototoxicity.

Nanosized π-Conjugated Molecules Based on Truxene and Porphyrin: Synthesis and High Fluorescence Quantum Yields

[reaction: see text] A series of novel nanosized pi-conjugated molecules based on both truxene and porphyrin moieties with high fluorescence quantum yields have been prepared via the Suzuki cross-coupling and the Lindsey reactions. The investigation of optical properties demonstrates that various aryl groups as the antenna efficiently enhance the intramolecular and intermolecular energy transfer. These nanosized macromolecules emitting intense red light might be good candidates for photonic and electronic devices.