Kati Rinnekari: Nanocellulose-based bioinks for in vitro tissue engineering

The development of physiologically relevant in vitro tissue models is essential for advancing our understanding of tissue development, disease mechanisms, and therapeutic discovery. This doctoral research focuses on engineering three-dimensional tissue models using animal-free, nanocellulose-based hydrogels as biomimetic extracellular matrices. The overarching aim is to enhance the structural and functional resemblance of in vitro models to native human itissues by developing bone, vasculature, and vascularized adipose tissue models. 

The work is divided into three parts, all utilizing extrusion-based 3D bioprinting with nanocellulose-based bioinks. In the first part, bone tissue models are fabricated using nanocellulose- and hyaluronic acid-based bioinks combined with human bone marrow-derived stem/stromal cells (hBMSCs), with osteogenic differentiation further enhanced by bioactive glass dissolution products. The second part focuses on investigating cell–material interactions and vascularization using nanocellulose-based bioinks in combination with human umbilical vein endothelial cells (HUVECs) and human adipose derived stem/stromal cells (hASCs). In the third part, vascularized adipose tissue models are developed through dual-printing strategies that enable spatial organization of adipogenic and vascular components within the constructs. 

Nanocellulose is explored as a sustainable and functional biomaterial with the potential to improve bioink printability, mechanical properties, and angiogenic performance. The engineered models are characterized through comprehensive analyses of both cellular responses and material properties. It is hypothesized that nanocellulose-based hydrogels will promote vascularization, enhance tissue maturation, and support prolonged culture conditions.

Overall, this work aims to contribute to the development of advanced, animal-free tissue models that better replicate human physiology, thereby supporting applications in disease modeling, drug testing, and regenerative medicine.