Reduction-responsive molecularly imprinted nanogels for drug delivery applications

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Molecularly imprinted polymers (MIPs) are synthetic receptors with tailored recognition properties.
• Developing degradable MIPs is crucial for controlled drug delivery applications.
• Disulfide bonds offer a promising strategy for creating stimuli-responsive polymer networks.

Purpose of the Study:

• To synthesize and characterize degradable MIPs for S-propranolol recognition.
• To investigate the degradation mechanism and its effect on binding properties.
• To explore the potential of these MIPs as intracellular controlled drug delivery systems.

Main Methods:

• Copolymerization of methacrylic acid and a disulfide cross-linker (DSDMA) to create MIPs.
• Bulk and high dilution polymerization techniques for nanogel synthesis.
• Batch binding experiments to assess specificity and selectivity for S-propranolol.
• Degradation studies using reducing agents (NaBH4, DTT, GSH) and analysis of polymer properties (turbidity, viscosity, size, IR spectra).

Main Results:

• DSDMA-based MIPs demonstrated specific affinity for S-propranolol, comparable to traditional EDMA-based MIPs.
• Nanosized MIPs successfully degraded upon exposure to reducing agents, cleaving disulfide bonds.
• Degradation led to a loss of binding capacity and recognition specificity.
• Controlled release of S-propranolol was achieved, with higher release rates in the presence of glutathione (GSH).

Conclusions:

• Degradable MIPs utilizing disulfide cross-linkers can be synthesized for selective S-propranolol binding.
• The cleavage of disulfide bonds provides a mechanism for controlled polymer degradation and drug release.
• These materials show potential as stimuli-responsive systems for intracellular drug delivery.