Radachlorin-Containing Microparticles for Photodynamic Therapy.

Area of Science:

• Biomaterials Science
• Photodynamic Therapy
• Drug Delivery Systems

Background:

• Photodynamic therapy (PDT) faces challenges with systemic side effects.
• Microparticles (MPs) can encapsulate photosensitizers to improve PDT efficacy and localization.
• Radachlorin (RC) is a natural photosensitizer with potential therapeutic applications.

Purpose of the Study:

• To prepare biocompatible, biodegradable MPs incorporating the natural photosensitizer Radachlorin (RC).
• To evaluate the potential of these RC-loaded MPs for targeted photodynamic therapy.
• To characterize the physical properties, drug release, and in vitro efficacy of the developed MPs.

Main Methods:

• Preparation of RC-containing MPs (RC MPs) using poly(lactic-co-glycolic acid) (PLGA) via double emulsion solvent evaporation.
• Characterization of RC MPs size, morphology, and RC content using SEM, CLSM, DLS, and optical spectroscopy.
• In vitro assessment of cellular uptake, prolonged RC release, singlet oxygen generation, and photocytotoxic effect on tumor cells.

Main Results:

• PLGA RC MPs were successfully prepared with an average diameter of 2-3 μm.
• The water/oil/oil method yielded significantly higher RC loading (1.74 μg/mg) compared to water/oil/water (0.089 μg/mg).
• RC MPs exhibited sustained RC release over two weeks, generated singlet oxygen upon light exposure, and demonstrated a photoactivated cytotoxic effect on tumor cells.

Conclusions:

• PLGA-based RC MPs are effective in delivering Radachlorin for photodynamic therapy.
• These MPs show potential for localized PDT applications, reducing systemic toxicity.
• The developed RC MPs offer a promising strategy for enhanced tumor treatment via PDT.