Deciphering physical and functional properties of chitosan-based particles for agriculture applications

Abstract

Traditional methods for controlling plant pathogens rely on toxic chemicals, posing environmental and healthrisks. Developing sustainable, eco-friendly alternatives is crucial. Chitosan (CS)-based materials offer promisingsolutions for sustainable agriculture. We aimed to synthesize and characterize CS-based microparticles withvarying properties and assess their antimicrobial performance to establish correlations between variations inphysicochemical characteristics and their impact on performance within biological systems. We adjusted thesynthesis parameters, producing particles labeled P1, P2, and P3, which have sizes of 0.19 ± 0.07 μm, 0.45 ±0.32 μm, and 1.22 ± 0.32 μm, and zeta potentials of +7.6 ± 4.25 mV, +22 ± 3.51 mV, and + 12.9 ± 4.54 mV,respectively. Extensive toxicological screenings showed that these CS-based microparticles were non-toxic acrosscell cultures, mouse red blood cells, soil microbiota, nitrogen-cycling bacteria, and plant toxicity assays.Encouraged by these results, we evaluated their antimicrobial potential against economically important croppathogens. The CS-based microparticles exhibited antimicrobial effects against the bacterium Pseudomonassyringae pv. tomato DC3000 and the fungus Fusarium solani f. sp. eumartii. Higher zeta potentials correlated withgreater antimicrobial efficacy, evidenced by lower IC50 and minimum inhibitory concentration (MIC) values.These findings indicate that all three microparticles analyzed displayed antimicrobial activity against twoeconomically significant crop pathogens, with P2 showing solid performance attributed to its physicochemicalcharacteristics. Therefore, CS-based microparticles represent a promising, nontoxic, and environmentallyfriendly alternative for modern agriculture, with their biological activities potentially predictable through carefulselection of physicochemical properties before the synthesis process.