Alternative Controlling Agent of Pests: Nanoscale Surface and Fractal Analysis of Gelatin/PCL Loaded Particles Containing Essential Oil.

A new systematic structural study was performed using the Atomic Force Microscopy (AFM) reporting statistical parameters of polymeric particles based on gelatin and poly--caprolactone (PCL) containing essential oil from . The developed biocides are efficient alternative controlling agents of and , the main pests of . Our results showed that the particles morphology can be successfully controlled by advanced stereometric parameters, pointing to an appropriate concentration of encapsulated essential oil according to the particle surface characteristics. For this reason, the absolute concentration of 1000 µg·mL (P system) was encapsulated, resulting in the most suitable surface microtexture, allowing a faster and more efficient essential oil release. Loaded particles presented zeta potential around (-54.3 ± 2.3) mV at pH = 8, and particle size distribution ranging from 113 to 442 nm. The hydrodynamic diameter of 90% of the particle population was found to be up to (405 ± 31) nm in the P system. The essential oil release was evaluated up to 80 h, with maximum release concentrations of 63% and 95% for P and P, respectively. The best fit for the release profiles was obtained using the Korsmeyer-Peppas mathematical model. Loaded particles resulted in 100% mortality of up to 48 h. The antifungal tests against resulted in a minimum inhibitory concentration of 250 µg·mL, and the P system produced growth inhibition up to 7 days. The developed system has potential as alternative controlling agent, due to its physical stability, particle surface microtexture, as well as pronounced bioactivity of the encapsulated essential oil.