Desenvolvimento de nanocompósitos de quitosana e nanocelulose obtida por liquídos iônicos para mimetização óssea

Abstract

The use of chitosan (CS) in the production of scaffolds, three-dimensional (3D), porous structures that play an important role as support for the growth of new tissues, has emerged as a promising alternative for biomedical applications, particularly in bone tissue regeneration. However, the low mechanical strength of these materials suggests the incorporation of nanomaterials, such as nanocellulose (NC), to provide structural reinforcement and broaden their application potential. NC is biodegradable, biocompatible, renewable, and exhibits a high surface area and mechanical strength, but its traditional production by acid hydrolysis (H₂SO₄ and HCl) leads to environmental impacts. In this context, ionic liquids (ILs) can be employed as a sustainable alternative for producing these nanoparticles. This study aimed to map technologies involving cellulose dissolution methods in ILs, identify major technological gaps, and develop CS-based scaffolds reinforced with NC obtained from ILs to support bone tissue regeneration. NC was produced from eucalyptus pulp using the ionic liquid 3-dimethylamino1-propylammonium hexanoate (DMAPA[Hex]) and characterized in terms of yield, zeta potential, Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). A central composite design (CCD) was used to optimize reaction time and temperature. Patent analysis indicated that the technology is in an early stage of maturity, with a predominance of applications in polymer chemistry and machinery, while uses in medical, pharmaceutical, and micro/nanotechnology fields remain incipient, representing opportunities for innovation. The optimal condition identified was 75 °C for 14.5 h, resulting in stable cellulose nanofibrils (CNF) with well-defined morphology and a zeta potential of approximately 7.0 mV, favorable for colloidal stability. The nanostructured scaffolds composed of purified chitosan (CS-P) and CNF were produced in 3D format and characterized by XRD, scanning electron microscopy (SEM), FTIR, and in vitro cell viability assays. The structures exhibited interconnected porous networks with pores larger than 100 µm, providing a voluminous matrix suitable for cell growth. CS-P improved the structural integrity of the biomaterial, and cell viability tests demonstrated high biocompatibility. The integration of technical performance, biocompatibility, and environmental responsibility positions the CNF/CS-P scaffolds as promising candidates for regenerative medicine and advanced biomaterials research.