Soy protein isolate-carboxymethyl cellulose conjugates with pH sensitivity for sustained avermectin release

Area of Science:

• Materials Science
• Biotechnology
• Agricultural Chemistry

Background:

• Soy protein isolate (SPI) and carboxymethyl cellulose (CMC) are biocompatible polymers.
• Avermectin (AVM) is a widely used insecticide facing challenges with stability and delivery.
• Developing advanced delivery systems is crucial for enhancing pesticide efficacy and reducing environmental impact.

Purpose of the Study:

• To synthesize and characterize soy protein isolate-carboxymethyl cellulose conjugate (SPC) for drug encapsulation.
• To encapsulate avermectin (AVM) into SPC to create SPC@AVM microspheres.
• To evaluate the physicochemical properties, stability, and efficacy of SPC@AVM as a pesticide formulation.

Main Methods:

• Grafting CMC onto SPI to form SPC, followed by hydrophobic encapsulation of AVM.
• Characterization using infrared spectroscopy, thermal analysis, SDS-PAGE, and scanning electron microscopy.
• Evaluation of zeta potential, wettability, liquid holding capacity, UV photolysis resistance, and pH-responsive release.

Main Results:

• SPC@AVM microspheres exhibited an average particle size of 129 nm and spherical morphology.
• Enhanced stability (zeta potential > 15 mV), improved leaf wettability (contact angle reduced to 57.33°), and increased liquid holding capacity.
• Significantly prolonged AVM half-life under UV light (from 18 to 68 min), retaining insecticidal activity and demonstrating pH-responsive release.

Conclusions:

• The developed SPC@AVM conjugate provides a stable and effective delivery system for avermectin.
• This formulation enhances pesticide performance by improving leaf adhesion, UV protection, and controlled release.
• The findings suggest a promising approach for developing advanced, eco-friendly pesticide formulations.