Alternative Controlling Agent of Theobroma grandiflorum Pests: Nanoscale Surface and Fractal Analysis of Gelatin/PCL Loaded Particles Containing Lippia origanoides Essential Oil

Abstract

A new systematic structural study was performed using the Atomic Force Microscopy (AFM) reporting statistical parameters of polymeric particles based on gelatin and poly-ε-caprolactone (PCL) containing essential oil from Lippia origanoides. The developed biocides are efficient alternative controlling agents of Conotrachelus humeropictus and Moniliophtora perniciosa, the main pests of Theobroma grandiflorum. 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−1 (P1000 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 P1000 system. The essential oil release was evaluated up to 80 h, with maximum release concentrations of 63% and 95% for P500 and P1000, respectively. The best fit for the release profiles was obtained using the Korsmeyer–Peppas mathematical model. Loaded particles resulted in 100% mortality of C. humeropictus up to 48 h. The antifungal tests against M. perniciosa resulted in a minimum inhibitory concentration of 250 µg·mL−1, and the P1000 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.

Electrolyte pH dependence of composition, roughness parameters, particle diameter and magnetic features of nanostructured Fe‐Co‐Ni/ITO deposits prepared by electrochemical deposition method

“…The obtained surface skewness values (> 0) indicate the presence of a spiky surface with sharp peaks and low valleys in all films 48–52 . The resulting surface kurtosis values (> 3) show that all film surfaces exhibit leptokurtic height distribution with sharp peaks 50,53 . Besides, the surface skewness and surface kurtosis increase slightly as the electrolyte pH is decreased from 4.7 to 3.9, and then increase sharply when the pH of the electrolyte is decreased from 3.9 to 3.2.…”

“…[48][49][50][51][52] The resulting surface kurtosis values (> 3) show that all film surfaces exhibit leptokurtic height distribution with sharp peaks. 50,53 Besides, the surface skewness and surface kurtosis increase slightly as the electrolyte pH is decreased from 4.7 to 3.9, and then increase sharply when the pH of the electrolyte is decreased from 3.9 to 3.2. This means that the surface of the film manufactured at low electrolyte pH of 3.2 exhibits sharper protruding proper- ties than the surface of the films produced at high pH values.…”

Biodefensive Based on Piper nigrum Essential Oil for Controlling of Anopheles aquasalis Larvae: Influence of Temperature (35 °C) and Preservatives

“…The numerous advantages of biodefensives have stimulated a growing interest in the development of novel formulations based on bioactive molecules such as plant secondary metabolites [ 8 , 9 ]. For this reason, essential oils have been extensively investigated as alternative controlling agent due to their important fungicide, insecticide and larvicidal properties [ 8 , 10 , 11 , 12 ]. The effectiveness of the essential oil from black pepper ( Piper nigrum L.; Piperaceae), known in Brazil as “pimenta-do-reino”, was evaluated herein against Anopheles aquasalis (Diptera: Culicidae) larvae.…”

Development of Functional Nanomaterials for Applications in Chemical Engineering

“…Nanomaterials have also found extensive applications in the fields of daily chemical products, cosmetics, pesticides, biomedicine etc., where the nanomaterials can be used as nanocarriers to load various active components for targeted delivery and controlled release. Rocha et al [ 13 ] performed a systematic study on polymeric particles based on gelatin and poly- ε -caprolactone (PCL) containing essential oil from Lippia origanoides . The developed biocides have high physical stability and particle surface microtexture as well as pronounced bioactivity, which are efficient alternative controlling agents of Conotrachelus humeropictus and Moniliophtora perniciosa , the main pests of Theobroma grandiflorum .…”