Vaterite submicron particles designed for photodynamic therapy in cells

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Calcium carbonate (CaCO3) exists in multiple crystalline phases, including vaterite, calcite, and aragonite.
• Controlling polymorphism, particle size, and morphology is crucial for CaCO3 microparticle preparation.
• Vaterite CaCO3 microparticles are investigated for encapsulating photosensitizers for photodynamic therapy (PDT).

Purpose of the Study:

• To develop porous vaterite calcium carbonate (CaCO3) microparticles.
• To encapsulate chloro-aluminum phthalocyanine (ClAlPc) as a photosensitizer (PS).
• To evaluate the potential of ClAlPc-loaded CaCO3 microparticles in photodynamic therapy (PDT).

Main Methods:

• Spherical vaterite CaCO3 microparticles synthesized via precipitation with polycarboxylate superplasticizer (PSS).
• CaCO3 prepared by reacting Na2CO3 and CaCl2 solutions at 25 °C with PSS stabilizer.
• ClAlPc photosensitizer incorporated via adsorption; characterization by SEM, photophysical studies, and in vitro cytotoxicity assays.

Main Results:

• Synthesized uniform, non-aggregated, highly porous CaCO3 microparticles (3 μm) with 30-40 nm pores.
• Encapsulated ClAlPc retained photophysical properties and localized within cells.
• ClAlPc-loaded CaCO3 microparticles demonstrated significant phototoxicity, killing ~80% of cancer cells at specific concentrations and light doses, with no dark cytotoxicity.

Conclusions:

• Phthalocyanine-loaded CaCO3 microparticles show promise as a drug delivery system.
• The developed system is suitable for photodynamic therapy (PDT) applications.
• These microparticles are also suitable for other photoprocesses.