Enzyme Scaffolds with Hierarchically Defined Properties via 3D Jet Writing

The immobilization of enzymes into polymer hydrogels is a versatile approach to improve their stability and utility in biotechnological and biomedical applications. However, these systems typically show limited enzyme activity, due to unfavorable pore dimensions and low enzyme accessibility. Here, 3D jet writing of water‐based bioinks, which contain preloaded enzymes, is used to prepare hydrogel scaffolds with well‐defined, tessellated micropores. After 3D jet writing, the scaffolds are chemically modified via photopolymerization to ensure mechanical stability. Enzyme loading and activity in the hydrogel scaffolds is fully retained over 3 d. Important structural parameters of the scaffolds such as pore size, pore geometry, and wall diameter are controlled with micrometer resolution to avoid mass‐transport limitations. It is demonstrated that scaffold pore sizes between 120 µm and 1 mm can be created by 3D jet writing approaching the length scales of free diffusion in the hydrogels substrates and resulting in high levels of enzyme activity (21.2% activity relative to free enzyme). With further work, a broad range of applications for enzyme‐laden hydrogel scaffolds including diagnostics and enzymatic cascade reactions is anticipated.In this article, the development and application of a water‐based bioink with preloaded enzymes is described. With 3D jet writing, a hydrodynamic jetting system, freestanding 3D hydrogel frameworks with defined micropores are brightened. The enzyme‐loaded scaffolds show a high enzymatic activity and can be tested for industrial use in a continuous flow reactor over several days.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162721/2/mabi202000154_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162721/1/mabi202000154.pd

Behavioral Economics and the Public Sector

This thesis consists of four essays dealing with topics that are relevant for the public sector. The essays cover diverse issues of economics partly overlapping with political science. The topics reach from the taxation of labor over monetary policy to preferences over voting institutions. Throughout this thesis it is, in contrast to classical economics, not assumed that humans are necessarily fully rational. Once full rationality is no longer assumed, experiments become an important tool to learn about human behavior. Consequently, most of the work in this thesis makes use of economic experiments