Valorization of cellulose and lignin to produce materials with potential application in the medical and packaging areas

Abstract

Lignocellulosic materials are low-cost renewable resources that can be valued if properly used alone or as an additive in the synthesis of other materials. In this project, single-use films (with potential application in the packaging area) and two types of biomaterials (to be used in the medical area) will be developed. Nanofibrillated cellulose (CNF), bacterial cellulose (BC) and lignin (L) will be considered. Regarding the materials to be used in the medical field, as a first approach, Gallium ions (Ga+3), which have proven action against bone cancer, will be incorporated into bioactive glass (BG), already widely used in bone tissue engineering, forming Ga-BG. To reduce the fragility of Ga-BG, it will be incorporated into nanofibrillated cellulose. To further increase the functionality of this material, particles of poly(D,L-lactic-co-glycolic) acid (PLGA-NPs) carrying curcumin will also be incorporated. The action of curcumin against several types of cancer is also well reported in the literature. In a second approach, bacterial cellulose hydrogels will be produced, which will undergo chemical modification of their surface through phosphorylation, in order to improve the adhesion of hydroxyapatite (HAp) on BC. HAp is already used as a bone substitute in the dental field, with osteoconductive and osteoinductive properties. Finally, calcium oxide (CaO) will be incorporated into the CB/HAp hydrogels, forming CB/HAp/CaO. The combination of the organic structure of BC with inorganic materials (CaO and HAp) can provide characteristics similar to those of bone, and the release of calcium ions can help in the repair of bone tissue. The CB/HAp/CaO hydrogel can be dried to produce a scaffold with high porosity and surface area, which can provide structural support for cell migration, proliferation, and attachment. In the case of films, gelatin and lignin functionalized with quaternary ammonium compounds (CCA) will be used, which makes the lignin hydrophilic and potentially antimicrobial. (AU)