Polymeric Micelles Encapsulating Photosensitizer: Structure/Photodynamic Therapy Efficiency Relation

Abstract

Various polymeric micelles were formed from amphiphilic block copolymers, namely, poly(ethyleneoxide-b-ε-caprolactone), poly(ethyleneoxide-b-d,l-lactide), and poly(ethyleneoxide-b-styrene). The micelles were characterized by static and dynamic light scattering, electron microscopy, and asymmetrical flow field-flow fractionation. They all displayed a similar size close to 20 nm. The influence of the chemical structure of the block copolymers on the stability upon dilution of the polymeric micelles was investigated to assess their relevance as carriers for nanomedicine. In the same manner, the stability upon aging was assessed by FRET experiments under various experimental conditions (alone or in the presence of blood proteins). In all cases, a good stability over 48 h for all systems was encountered, with PDLLA copolymer-based systems being the first to release their load slowly. The cytotoxicity and photocytotoxicity of the carriers were examined with or without their load. Lastly, the photodynamic activity was assessed in the presence of pheophorbide a as photosensitizer on 2D and 3D tumor cell culture models, which revealed activity differences between the 2D and 3D systems.

Near‐Infrared‐Light‐Activatable Nanomaterial‐Mediated Phototheranostic Nanomedicines: An Emerging Paradigm for Cancer Treatment

“…Furthermore, micelles also facilitate control of the drug release at a specific site by diffusion, polymer degradation, or micelle dissociation mechanisms. Such micelles also exhibit long blood‐circulation times and tumor selectivity based on the EPR effect, thus decreasing the nonspecific biodistribution of hydrophobic PSs …”

“…Alternatively, biodegradable polymers, such as chitosan, dextran, collagen, gelatin, and others, were also used as nanocarriers for the delivery of photosensitizer drugs . Thus, hyaluronic acid nanoparticles (HANPs) contained Ce6 for simultaneous imaging and PS‐PDT.…”

Roles of ligand and TPGS of micelles in regulating internalization, penetration and accumulation against sensitive or resistant tumor and therapy for multidrug resistant tumors

“…In this research, FRET method was used to verify the structure and structural integrity of the hybrid micelles. When DiO/DiI coloaded hybrid micelles were excited at 494 nm, the energy of the donor DiO could transfer to the acceptor DiI, which results in a decrease of fluorescence intensity of DiO and a crosscurrent of fluorescence intensity of DiI [39]. In addition, only the distance between two fluorophores was less than 10 nm could the FRET phenomenon occurred.…”

Improved Photodynamic Therapy Efficacy of Protoporphyrin IX-Loaded Polymeric Micelles Using Erlotinib Pretreatment

“…10, 11 Among the many nanoparticulate systems, polymeric micelles are of particular interest for encapsulating hydrophobic PDT drugs. 12, 13, 14, 15 Composed of amphiphilic block copolymers, these micelles have a hydrophilic corona, typically poly(ethylene glycol), and a hydrophobic core into which hydrophobic drugs can be incorporated. These nanocarriers are mostly biocompatible, degradable, and have a prolonged circulation time with enhanced tumor accumulation, allowing them to function as ideal carriers for hydrophobic drugs.…”