Microscopy-based infrared spectroscopy as a tool to evaluate the influence of essential oil on the surface of loaded bilayered-nanoparticles

Abstract

Increasing interest in nanoparticles of technological application has been improving their fabrication processes. The encapsulation of essential oils as bioactive compounds has proved to be an excellent alternative to the use of less environment friendly compounds. However, the difficulty of identifying their constitution and interaction with carrier agents have aroused scientific interest and a problem to overcome. Bilayer-based nanoparticles were developed using gelatin and poly-ε-caprolactone (PCL) aiming the encapsulation of Piper nigrum essential oil. based on atomic force microscopy images and dynamic light scattering analysis, the size of the unloaded and loaded nanoparticles was found around (194 ± 40) and (296 ± 54) nm, respectively. The spatial patterns revealed that the surface of nanoparticles presented different surface roughness, similar shapes and height distribution asymmetry, lower dominant spatial frequencies, and different spatial complexity. Traditional infrared spectroscopy allowed the identification of the nanoparticle outermost layer formed by the gelatin carrier, but microscopy-based infrared spectroscopy revealed a band at 1742 cm−1 related to the carbonyl stretching mode of PCL, as well as a band at 1557 cm−1 due to the amide II group from gelatin. The combination of microscopy and spectroscopy techniques proved to be an efficient alternative to quickly identify differences in chemical composition by evaluating different functional groups in bilayer PLC/gelatin nanoparticles of technological application.

Pulsatile Controlled Release and Stability Evaluation of Polymeric Particles Containing Piper nigrum Essential Oil and Preservatives

“…Figure 10 schematically shows a speculative proposal for the interpretation of the controlled release of the PNE system associated with the particle design [ 26 , 114 ]. Figure 10 a shows a particle consisting mainly of gelatin, PCL, and essential oil, as well as the concentration of essential oil located within the particle.…”

“…Colloidal systems consisting of biodegradable carriers were developed herein, based on the addition of different preservatives. The combination of gelatin and poly- ε -caprolactone (PCL) represents a technological alternative for new particle designs, allowing specific release mechanisms, as well as an enhanced encapsulation efficiency and biodegradability [ 10 , 26 , 27 , 28 ]. However, specific stability tests are required to evaluate the behavior of a formulation as a function of time [ 10 , 29 ].…”

Nanoscale surface dynamics of spatial patterns of polymeric bilayered particles loaded with essential oil

“…P. nigrum essential oil was obtained through powdered seeds on a Clevenger‐type apparatus (Costa et al, 2021; da Costa et al, 2021). Colloidal systems were synthesized as follows: solution I was prepared by heating gelatin at 50°C in distilled water under constant magnetic stirring.…”

“…As a result, novel systems can be prepared with enhanced water dispersibility, specific controlled release mechanisms and surface functionalization allowing their action on targeting ligands. Moreover, some reports have also pointed to the evaluation of spatial patterns of surfaces for biotechnological applications (da Costa et al, 2021; de Oliveira et al, 2017, 2020; Matos et al, 2018; Matos, Ramos, et al, 2020).…”

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

“…The combination of biomaterials with different physicochemical properties has allowed the development of layered particles, to protect and release secondary metabolites [ 14 , 15 , 16 , 17 ]. The evaluation of surface nanotexture and fractal analyses through Atomic Force Microscopy (AFM) technique has been useful to investigate the influence of texture parameters on the controlled release mechanism and concentration of encapsulated bioactive compounds [ 18 , 19 ].…”