The primary objective of the first year of the project has been to optimize the silk-based bioink for 3D bioprinting with the right balance of viscosity and stiffness to ensure smooth printing, precise layer formation, and gel-like consistency. The bioink has been developed to support HSPC viability, proliferation, and differentiation through appropriate biochemical cues.
Effective printing protocols have been set to ensure high repeatability, standardization, fidelity of constructs, and reliable cell culture. We demonstrated that controlled extrusion of SILKink ensures homogeneous cell embedding, spatial distribution, and efficient nutrient diffusion, vital for proper cell viability, differentiation, and function. Particularly, SILKink supports the controlled differentiation of human HSPCs into platelets. Optical transparency allows high-resolution imaging of platelet generation, and enzymatic sensors enable quantitative analysis of glycolytic metabolism during differentiation, indicated by measurable color changes. Bioprinting samples from patients affected by Inherited Platelet Disorders provided a proof-of-concept of the applicability of the soft bone marrow mode as a tool for classifying thrombocytopenia and automating the assessment of responses to treatments at an individual scale.