N. Huynh: Engineering cellulose nanofibril hydrogels with bioactive phytochemicals: toward functional biomaterials

Abstract: 

Animal-derived biomaterials are currently the gold standard for cell culture and tissue engineering due to their biological relevance. However, their use entails high costs, ethical concerns as well as safety risks related to cross-species pathogen transmission. In contrast, plants represent an underutilized source of bioactive compounds and materials.

In this dissertation, Ngoc Huynh developed novel plant-based hydrogels by combining cellulose nanofibrils (CNF) with extracts from willow bark (WBE) and Aloe vera (AV). These hydrogels demonstrated enhanced mechanical strength and bioactivity. By exploring structure–property relationships, the study illustrates how material performance can be tailored through the strategic selection and ratio of components based on their interactions. Enhanced mechanical properties were observed in both hydrogels, though the mechanisms differed due to the distinct effects of WBE and AV.

The development process also involved investigating key aspects of CNFs, including their interactions with water and living cells. A quantitative analysis of cell-cell and cell-material interactions was conducted using atomic force microscopy-based techniques, to evaluate the suitability of CNFs as 3D cell culture environment. Results indicated that CNFs provide a biomimetic platform that supports cell viability and maintains crucial cell-cell adhesion.

In conclusion, this work demonstrates that high-performance, plant-based hydrogels can be engineered through novel design strategies. These materials show strong potential for biomedical applications and contribute to the replacement, reduction and refinement of animal use in biomedical research.

Keywords: Plant extracts, hydrogels, polysaccharides, cellulose nanofibrils, bioactive compounds, cell-material interactions

Opponent: Professor Kristin Syverud, Norwegian University of Science and Technology, Norway

Supervisor: Professor Monika Österberg, Aalto University School of Chemical Engineering

Link to electronic thesis: LINK

Link to the remote defense: LINK