Rational design of block copolymer self-assemblies in photodynamic therapy

Abstract

Photodynamic therapy is a technique already used in ophthalmology or oncology. It is based on the local production of reactive oxygen species through an energy transfer from an excited photosensitizer to oxygen present in the biological tissue. This review first presents an update, mainly covering the last five years, regarding the block copolymers used as nanovectors for the delivery of the photosensitizer. In particular, we describe the chemical nature and structure of the block copolymers showing a very large range of existing systems, spanning from natural polymers such as proteins or polysaccharides to synthetic ones such as polyesters or polyacrylates. A second part focuses on important parameters for their design and the improvement of their efficiency. Finally, particular attention has been paid to the question of nanocarrier internalization and interaction with membranes (both biomimetic and cellular), and the importance of intracellular targeting has been addressed.

Probing the Interactions of Porphyrins with Macromolecules Using NMR Spectroscopy Techniques

“…BCMs have gained much interest as versatile delivery systems for a wide range of drugs including porphyrinic PSs [ 54 , 55 ] and several recent comprehensive review articles have been devoted to the chemistry, properties and applications of BCMs [ 54 , 217 , 218 , 219 , 220 ]. The BCM forming units are biocompatible, mostly synthetic polymers consisting of a hydrophilic block forming the micellar shell and a hydrophobic block forming the micellar core ( Figure 11 ).…”

“…PEG is the most often encountered hydrophilic component of BCMs and in particular the triblock copolymers PEG-PPG-PEG, the so-called poloxamers or Pluronics (BASF trade name) [ 228 ], have been extensively explored as carriers for porphyrinic PSs [ 54 , 55 , 161 , 162 , 166 , 229 , 230 , 231 ]. BCM encapsulation is a strategy to enhance porphyrin delivery towards targeted tissue or profile the pharmacokinetics and pharmacodynamics of bioactive molecules.…”

“…Different strategies are applied in drug delivery of porphyrinic compounds, ranging from chemical binding to carrier or targeting molecules to physical entrapment into nanoparticles (NPs). Suitable NPs approved or under investigation consist of inorganic compounds [ 50 ], biodegradable carriers such as liposomes [ 51 , 52 , 53 ] or block copolymer micelles (BCMs) [ 54 , 55 ], molecular networks such as polyvinylpyrrolidone (PVP) [ 56 , 57 ] or cyclodextrins (CDs) [ 58 , 59 ] and numerous other materials [ 47 , 49 ]. In this vast range of biomedical applications, porphyrins are constantly exposed to macromolecules, either by the building blocks of their carrier materials or by the in vivo biological components such as plasma proteins or phospholipids in membranes.…”

Nanoparticle-Mediated Delivery Systems in Photodynamic Therapy of Colorectal Cancer

“…The application of nanotechnology as a fundamental tool to PDT in CRC is the key research direction to resolve some of the drawbacks that are associated with secondgeneration PSs and to improve selective cellular localisation in affected tumours [14,24]. Generally, third-generation PSs are comprised of second-generation PSs that are either anchored to or encapsulated by nanocarriers such as nanoparticles, liposomes or micelle carriers in order to increase the uptake and accumulation of NP-PSs by cancerous tissues [18,52]. The NPs can also be decorated with active targeting agents such as antibodies, biomarkers, or ligands in order to efficiently bind to receptors that are overexpressed on the surfaces of cancer cells [5,18].…”

Synthesis, Characterization and Self-Assembly Properties of a New Copper-Phthalocyanine Core Acrylate Block Copolymer

“…In the past decade, the synthesis of functional nano-architectures, aimed at developing electronic and photonic nano-devices to perform specific functions, such as catalysis, chemical sensing, electrical conductivity, photodynamic therapy, etc., has been an intense area of research [1][2][3][4][5][6][7][8][9][10]. Most of these activities are driven by the self-assembly and self-organization properties of molecules and require the incorporation of functional building blocks through a well-defined controlled process.…”