3D Druck und Health Tech Additive Verfahren mit biologischen Materialien Dr. Markus Rimann Zürcher Hochschule für Angewandte Wissenschaften (ZHAW) Fachgruppe Tissue Engineering
Background: 3D Cell Culture Why should we cultivate cells in three-dimensions (3D)? Humans are 3D Advantages of 3D cell culture Cell behavior between 2D and 3D is completely different (Proliferation, differentiation, metabolism) Different metabolic activity of 2D versus 3D, e.g. higher drug resistance of 3D Cell communication between cells is decreased in 2D, but crucial. 2D cell culture Drawbacks of current 3D cell culture technologies Limited control of cell distribution within a 3D system Integration of blood vessels difficult (to control) (Tissue size limited, O 2 - and nutrient limitation) => Artificial organs difficult Application in regenerative medicine and drug testing Provides reliable data Reduces animal experiments Accelerates cost-intensive process of drug development 3D cell culture 2
Background: Organs on demand Organs on demand Regenerative medicine Drug testing High organ structure complexity Schematc representation of kidney structure (ww.arizonatransplantassociates.com) Schematic representation of skin structure (www.intechopen.com) 3
Bioprinting Is the bioprinting technology the solution? Principle: Layer-by-layer deposition of biological material to produce 3D organotypic in vitro models Guillotin and Guillemot, 2011 3DDiscovery bioprinter, regenhu (www.regenhu.com) Flexibility in 3D shape Spatial control of cells, matrix and bioactive molecules (growth factors etc.) Standardized, automated and reproducible process High-throughput screening Integration of quality control 4
ZHAW research Standardization of a printing process for the manufacture of soft tissue models Approved printing device Cell-compatible bioink Choice of a soft tissue model as proof of concept 3DDiscovery BioInk TM Skin BioInk TM cartridge, regenhu Contraction Fibroblasts in collagen I gel Contracted collagen I gel Keratinocytes seeding User-friendly software 3DDiscovery printer, regenhu Sterile printing conditions Printing process in standard cell culture devices Air-lift....... Keratinocytes on top of dermis Keratinocytes differentiation 5
ZHAW research Bioprinter Sterile printing environment Cell-compatible printheads User-friendly software (CAD-program) Flexible system to cope with fast development of this technology Bioprinting technologies (Malda et al., 2013, Adv. Mat.) 6
ZHAW research Bioink Printable matrix to arrange cells in 3D (universal bioink) Cell-compatible, cell adhesion, cell migration Stiffness adjustable (bone, soft tissue) Fast polymerization (different modes) Ready-to-use commercial product BioInk Printed structures with bioink (Melchels et al., 2014, J. Mater. Chem. B.) 7
ZHAW research Cell-compatible printing process... BioInk TM Fibroblasts BioInk TM Human primary fibroblasts printed in BioInk TM dermis equivalents. Models stained with MTT after 2 days of culture show cell viability and a clear printing pattern The polymerization process of the matrix at 365nm ± 10nm doesn t cause DNA damages. ELISA analysis for the detection of cyclobutane pyrimidine dimers (CPD) Dermis equivalent scheme 8
International research Complex tissue structures with blood vessels Kolesky, Truby, Gladman, Busbee, Homan, Lewis Wyss Institute for Biologically Inspired Engineering, Harvard University, USA (Adv. Mat., 2014) Tissue production by extrusion technology (robotic dispensing, slide 6). Left: Principle of a printed construct (ECM: extracellular matrix), right top: Scheme of the printed structure, right bottom: Printed construct with differently colored cell types. Different bioinks are printed together Different cell types are precisely deposited within a 3D structure Blood vessel printing is feasible (not in one step) Larger tissue constructs are printable because of vasculature integration 9
International research Printed liver Printed liver harboring three different cell types. Organovo, San Diego, CA 92121, USA Liver complexity (http://www.cosmiq.de/qa/show/2802267/hat -der-mensch-eine-leber-oder-zwei/) Three different cell types were printed in the same construct Liver-specific functions were reported Liver complexity not achieved 10
International research Printed kidney Printed kidney. Atala, Wake Forest Institute for Regenerative Medicine, Winston Salem, NC 27157, USA, Printed kidney shape harboring cells Kidney complexity not achieved Kidney functionality not achieved Kidney complexity (http://www.jameda.de/gesundheitslexikon/niere/) 11
Summary Bioprinting has a huge potential in substance testing and regenerative medicine Technology is still in its infancy Printing of simple structures (resolution?) Lack of standardization and reproducibility Research groups are fabricating their own bioprinters Research groups are synthesizing their own bioinks Few commercially-available bioprinters Technology at high level Few commercially-available bioinks Cell-compatibility is important and difficult to achieve Thorough material characterization is necessary (stiffness, viscosity, degradability) Bioink properties (Malda et al., 2013, Adv. Mat.) 12
Acknowledgements Danke für Ihre Aufmerksamkeit Prof. Dr. Ursula Graf-Hausner Dr. Epifania Bono Helene Annaheim Matthias Bleisch Tissue Engineering Team Marc Thurner Michael Kuster Andreas Scheidegger 13