Human tissues and organs are intricate structures where different biological and physical characteristics create a seamlessly functioning whole. Unlike traditional tissue engineering methods, 3D bioprinting offers an automated and highly precise method to deposit bioinks – materials containing living cells – layer-by-layer into three-dimensional tissue constructs.
Before this technology can be used to produce transplantable tissues for clinical applications, clinically compatible raw materials and cell sources must be developed. In addition, accurately mimicking the complex architecture of human tissues requires the precise placement of different cells and materials within a single tissue construct – however, the development of multi-material bioprinting techniques has received only limited attention in the field to date.
In her doctoral dissertation research, Paula Puistola applied the developed materials and methods to corneal bioprinting. The human cornea is among the tissues in critical shortage, with a lack of donor material severely limiting treatment options for corneal blindness. Corneal blindness affects millions of people worldwide and their quality of life, and these patients could be treated with bioprinted corneas.
“The human cornea consists of multiple layers and cell types, making it well-suited for multi-material bioprinting approaches. The thickest layer of the cornea, the stroma, plays a key role in maintaining its mechanical strength and transparency. These crucial properties require accurate stromal microstructure. However, this delicate microstructure has not previously been mimicked using 3D bioprinting, and my research addresses this gap in knowledge”, Puistola explains.
Current raw materials used in bioprinting are often animal-derived or non-biodegradable. The clinical translation of animal-derived biomaterials is limited due to immunological risks, ethical concerns and challenges in achieving consistent quality and standardization. Furthermore, non-biodegradable biomaterials can interfere with the body’s natural healing process, as they remain in the body during tissue regeneration. To address these challenges, Puistola developed animal-free and biodegradable, biologically relevant bioinks which support cellular growth and tissue formation. This development was conducted in close collaboration with Senior Research Fellow Anni Mörö who is one of the top names in the field.
“Although much work remains before we achieve fully functional bioprinted human tissue replicas, what once sounded like science fiction is now closer than ever. In addition to technological development, it is also essential to improve the scalability and cost-effectiveness of these methods to ensure that future treatments remain affordable”, Puistola concludes.
Paula Puistola is originally from Janakkala and currently works as COO at LifeGlue Technologies Oy, which is a spin-out company from Tampere University and founded on the novel research innovation in bioink development. Moreover, she will continue part-time as a postdoctoral researcher at Eye Regeneration Group led by Professor Heli Skottman at Tampere University, advancing the development of 3D bioprinted corneas.
Public defense on Friday 26 September
The doctoral dissertation of MSc (Tech) Paula Puistola in the field of medicine, biosciences and biomedical engineering titled Developing Clinically Compatible Bioinks and Novel Multi-material 3D Bioprinting Strategies – Applications in Human Stem Cell Based Cornea will be publicly examined at the Faculty of Medicine and Health Technology at Tampere University at 12 o’clock on Friday 26 September 2025 at Kauppi campus, Arvo building, auditorium F114 (Arvo Ylpön katu 34, Tampere). The Opponent will be Professor Sandra Van Vlierberghe from Ghent University, Belgium. The Custos will be Professor Heli Skottman from the Faculty of Medicine and Health Technology.