Chitosan-Alginate-Loaded Spinosad: Enhanced Cytotoxicity and Insecticidal Activity against Spodoptera frugiperda

Area of Science:

• Agricultural Science
• Materials Science
• Environmental Science

Background:

• Spinosad is an effective insecticide but suffers from poor environmental stability, limiting its practical application.
• Developing stable and efficient pesticide delivery systems is crucial for sustainable agriculture.

Purpose of the Study:

• To fabricate and characterize spinosad-loaded chitosan-sodium alginate particles (CS-ALG@Spi).
• To evaluate the enhanced stability, controlled release, and insecticidal efficacy of the CS-ALG@Spi formulation.
• To investigate the underlying mechanisms of its cytotoxicity against Spodoptera frugiperda.

Main Methods:

• Fabrication of spinosad-loaded chitosan-sodium alginate particles.
• Characterization of particle morphology, size, dispersion, and stability.
• Assessment of UV stability and acid-responsive release kinetics.
• Bioassays against Spodoptera frugiperda larvae and in vitro cytotoxicity assays.

Main Results:

• CS-ALG@Spi microspheres showed regular morphology, suitable size, and good dispersion.
• The formulation exhibited enhanced UV stability and acid-responsive release compared to free spinosad.
• CS-ALG@Spi significantly improved insecticidal activity against Spodoptera frugiperda, causing midgut damage.
• In vitro assays revealed cytotoxic effects including ROS generation, cell cycle arrest, and mitochondrial dysfunction.

Conclusions:

• The developed CS-ALG@Spi formulation offers enhanced stability and efficacy for spinosad.
• This study presents a viable and eco-friendly strategy for advanced pesticide delivery systems.
• The formulation's mechanism involves inducing oxidative stress and disrupting cellular processes in target pests.