Agathe Figarol
University of Toulouse, France
Title: Polymeric self-assemblies for photodynamic therapy: a critical approach
Biography
Biography: Agathe Figarol
Abstract
Statement of the Problem: The work presented here suggests a new approach in the critical development of polymeric nanovectors for photodynamic therapy (PDT) against cancer. Whereas hundreds of studies quickly jump forward from formation of self-assemblies to biological application without having a thorough examination of the vector solution, we suggest having a parallel assessment of formation/characterization of the nanovectors and their biological activity. This is possible by first conducting a careful physical chemistry characterization of the vectors by both batch techniques (light and neutron scattering, electron microscopy, atomic force microscopy) and Asymmetrical Flow Field-Flow Fractionation (AsFlFFF) coupled to adequate detectors (refractometry, light scattering). This enables us to fully characterize the vectors regarding purity, size and zeta potential. Methodology & Theoretical Orientation: Data on both polymeric micelles and polymersomes are presented here, using`poly(ethyleneoxide-b-e-caprolactone), poly(ethyleneoxide-b-D,Llactide) and poly(ethyleneoxide-b-styrene). Self-assemblies exhibiting size range of 20-200 nm are presented and reveal the possible presence of different populations of nanovectors in some cases. Controlled mixtures of different nano-objects are also studied, as well as crosslinked systems. For each new vector, its ability to carry a photosensitizer (Pheophorbide a) for PDT is examined. The activity in PDT either in 2D and 3D cell culture is presented and compared on different batches, in link with the purity analysis. Here again, it becomes highly recommended to develop a critical approach considering in vitro analyses, since different efficiencies are clearly observed depending on the vectors and the 2D or 3D culture type.Conclusion & Significance: This work shows that selected mixtures of different vectors with different morphologies or sizes may lead to synergetic effects. Also, a strong influence of the crosslinking of thevector has been observed and will be presented (Figure 1).