Encapsulation of Hydrophobic Phthalocyanine with Poly(N-isopropylacrylamide)/Lipid Composite Microspheres for Thermo-Responsive Release and Photodynamic Therapy

Abstract

Phthalocyanine (Pc) is a type of promising sensitizer molecules for photodynamic therapy (PDT), but its hydrophobicity substantially prevents its applications. In this study, we efficiently encapsulate Pc into poly(N-isopropylacrylamide) (pNIPAM) microgel particles, without or with lipid decoration (i.e., Pc@pNIPAM or Pc@pNIPAM/lipid), to improve its water solubility and prevent aggregation in aqueous medium. The incorporation of lipid molecules significantly enhances the Pc loading efficiency of pNIPAM. These Pc@pNIPAM and Pc@pNIPAM/lipid composite microspheres show thermo-triggered release of Pc and/or lipid due to the phase transition of pNIPAM. Furthermore, in the in vitro experiments, these composite particles work as drug carriers for the hydrophobic Pc to be internalized into HeLa cells. After internalization, the particles show efficient fluorescent imaging and PDT effect. Our work demonstrates promising candidates in promoting the use of hydrophobic drugs including photosensitizers in tumor therapies.

Microparticles-in-Thermoresponsive/Bioadhesive Hydrogels as a Novel Integrated Platform for Effective Intra-articular Delivery of Triamcinolone Acetonide

“…The characteristic bands of plain G-1 and G-2 formulations and TA-loaded MPs, previously published, were maintained nearly unchanged in both LG-1 and LG-2 formulations and no new bands were detected, as shown in Figure . , This confirms the absence of any new bonds that could be formed within the MPs–hydrogel formulations, indicating that the interaction between TA-loaded MPs and both G-1 and G-2 hydrogels is most probably hydrophobic in nature. Similar results were previously obtained by Liu et al…”

“…17,27 This confirms the absence of any new bonds that could be formed within the MPs−hydrogel formulations, indicating that the interaction between TAloaded MPs and both G-1 and G-2 hydrogels is most probably hydrophobic in nature. Similar results were previously obtained by Liu et al 52 3.4.4. Viscosity Measurements.…”

Kinetic Control in the Regioselective Alkylation of Pterin Sensitizers: A Synthetic, Photochemical, and Theoretical Study

“…One reason the solubility enhancement is so beneficial is that the reactions of pterins are not amenable to common organic solvents and purification techniques. In addition to solubility enhancements, it is logical to suggest an increase in the pterins' resistance against forming of aggregates due to alkylation, similar instances of deaggregation of porphyrins and other aromatics due to alkylation in organic solvents (57)(58)(59)(60)(61)(62)(63)(64)(65). This decrease in aggregation has proven necessary to improve sensitizer performance (66)(67)(68).…”

Recent Progress in Phthalocyanine-Polymeric Nanoparticle Delivery Systems for Cancer Photodynamic Therapy

“…Additionally, Liu et al [ 88 ] reported microgel particles consisting of poly(N-isopropylacrylamide)/lipid (pNIPAM/lipid) composite for thermo-responsive release of PDT agents. Microgel particles have emerged as an interesting system for drug delivery because they combine the unique properties of a gel with those of micro-/nanoparticles.…”