Advanced Microtexture Evaluation of Dextran Biofilms Obtained from Low Cost Substrate Loaded with Maytenus rigida Extract

Abstract

We have obtained kefir biofilms loaded with Maytenus rigida extract. The main goal was to evaluate the influence of the addition of the extract on the biofilms microtexture using stereometric and fractal parameters. Atomic force microscopy, Fourier transform infrared spectroscopy, and contact angle tecniques were used to evaluate the topography, chemical interation and wettability of the biofilms. Chemical evaluation showed that the extract interacts with the polymeric matrix of the biofilms, changing their structure. This behavior affected the surface energy because the wettability decreased when the Maytenus content increased. The surface morphology was also affected and suggested the prevalence of bacteria and yeast at lower and higher extract concentrations, respectively. The surface roughness increased according to the increase in the extract concentration. Texture parameters revealed that the biofilm with lowest concentration had deeper furrows than for higher concentration. Advanced fractal parameters revealed that topographic uniformity, percolation and texture homogeneity were more suitable for the biofilm with 0.25 g.L^-1 of extract. These results indicate that this biofilm have promising 3D micromorphology for regenerative medicine application. Furthermore, the physics tools used revealed to be very useful for characterizing of the microtexture of polymeric-based biological materials.

Keywords:
Kefir Biofilms; Maytenus rigida; Atomic force microscopy; Stereometric; Fractal parameters