Inovação sustentável em cosméticos: aplicações da nanocelulose bacteriana em biomáscaras e emulsões

Abstract

The growing demand for sustainable and innovative cosmetic products is driving the use of natural biopolymers such as bacterial nanocellulose (BCN). Produced by the biosynthesis of cellulose by bacteria such as Komagataeibacter xylinus, NCB is a promising material for applications in biocosmetics, such as biomasks and stabilized emulsions. The aim of this work was to develop cosmetic products based on NCB, functionalized with extracts of native Brazilian fruits, offering an innovative, high-quality and competitive alternative on the market. The research was divided into two main areas: (1) the production of face masks incorporated with plant extracts of jabuticaba and red araçá; and (2) the development of Pickering emulsions stabilized by oxidized NCB (NCB-OX). In Chapter 1, extracts were developed using the peels and seeds of red araçá and jabuticaba. These extracts were used to functionalize the NCB biomasks. The physical and structural properties were analyzed using water retention capacity, porosity, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Antioxidant activity and phenolic compounds were also determined. In Chapter 2, a Pickering emulsion was prepared by oxidizing NCB with the TEMPO reagent (2,2,6,6-Tetramethylpiperidine 1-oxyl). For characterization, stability tests were carried out by centrifugation, thermal stress and droplet size analysis, in addition to evaluating the rheological behaviour. In the results of Chapter 1, the biomasks showed high water retention capacity (99.10%) and high porosity (96.81%), essential characteristics for prolonged and effective skin hydration. Functionalization with plant extracts added significant antioxidant properties, with activity of over 75% in free radical inhibition tests. In chapter 2, the development of Pickering emulsions, the oxidation of NCB was decisive for its functionality as a stabilizer, promoting efficient stabilization of oil-water interfaces without the use of synthetic surfactants. The emulsions exhibited thermal and mechanical stability in the preliminary evaluations. The rheological behavior indicated that the emulsion is a nonNewtonian fluid with pseudoplastic behavior. This characteristic is ideal for dermal applications, as it improves its spreadability on the skin. Microscopic analysis revealed a homogeneous distribution of the droplets with an average diameter ranging from 11.53 nm to 39.52 nm over the course of 150 days, demonstrating that it is a nanoemulsion. The addition of jaboticaba extract contributed to the antioxidant capacity, resulting in 41.99 µmol ET.g-1. The results reinforce the versatility of NCB as a sustainable and efficient material for cosmetic applications. The bio-masks and emulsions developed stand out not only for meeting market demands for natural products, but also for promoting the use of renewable resources, such as agricultural by-products. It is concluded that bacterial nanocellulose, both in its pure and functionalized state, is a promising material for creating innovative cosmetics.