Light-Responsive and pH-Responsive DNA Microcapsules for Controlled Release of Loads

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Stimuli-responsive drug delivery systems are crucial for targeted therapies.
• Developing microcapsules with controlled release mechanisms remains a challenge.

Purpose of the Study:

• To develop a method for assembling light- and pH-responsive microcapsules.
• To load microcapsules with various payloads, including therapeutic agents.
• To evaluate the selective cytotoxicity of drug-loaded microcapsules.

Main Methods:

• Layer-by-layer deposition of nucleic acids on CaCO3 core microparticles.
• Functionalization of DNA shells for light-responsiveness (o-nitrobenzyl-phosphate) or pH-responsiveness (cytosine-rich layer).
• Dissolution of CaCO3 cores using EDTA to yield stimuli-responsive microcapsules.
• Controlled release of payloads upon light irradiation (365 nm) or acidic pH (pH 5.0).

Main Results:

• Successfully assembled light- and pH-responsive microcapsules loaded with TMR-D, MP-11, quantum dots, or DOX-D.
• Demonstrated payload release triggered by specific light wavelengths or pH conditions.
• DOX-D-loaded microcapsules exhibited selective cytotoxicity against MDA-MB-231 breast cancer cells compared to normal MCF-10A cells.

Conclusions:

• The described method provides a versatile platform for creating stimuli-responsive microcapsules.
• These microcapsules offer potential for targeted drug delivery with controlled release kinetics.
• Preliminary in vitro studies support the potential of DOX-D-loaded microcapsules in selective cancer therapy.