Gradient lithography of engineered proteins to fabricate 2D and 3D cell culture microenvironments

Abstract

Spatial patterning of proteins is a valuable technique for many biological applications and is the prevailing tool for defining microenvironments for cells in culture, a required procedure in developmental biology and tissue engineering research. However, it is still challenging to achieve protein patterns that closely mimic native microenvironments, such as gradient protein distributions with desirable mechanical properties. By combining projection dynamic mask lithography and protein engineering with non-canonical photosensitive amino acids, we demonstrate a simple, scalable strategy to fabricate any userdefined 2D or 3D stable gradient pattern with complex geometries from an artificial extracellular matrix (aECM) protein. We show that the elastic modulus and chemical nature of the gradient profile are biocompatible and allow useful applications in cell biological research.

Microfluidic probes for use in life sciences and medicine

“…25 Photolithographic technologies are highly developed for patterning surfaces with complex patterns. 26,27 However, they rely on harsh chemical processes that are not compatible with biological samples. Soft lithography, a technique where structures are fabricated using elastomeric stamps or molds, has allowed for more flexible and low-cost methods for tailoring and patterning surfaces.…”

Photoreactive interpenetrating network of hyaluronic acid and Puramatrix as a selectively tunable scaffold for neurite growth

“…Our model consisted of a photocrosslinkable polyethylene glycol (PEG) that surrounded an IPN hydrogel of methacrylated-HA and PM. By projecting UV light in defined geometries onto the photocrosslinkable substrates, the DMD enabled us to create a dynamic mask that could irradiate PEG and the IPN throughout the depth of the gel [17,[20][21][22][23]. We took advantage of this method in order to create a dual hydrogel system with a 3-D microenvironment to create an ideal in vitro environment for investigating neurite growth in the presence of varying mechanical properties.…”

Electrochemical Synthesis of Gold and Protein Gradients on Particle Surfaces

“…Photoactive molecules have likewise been used on the basis of photoimmobilization techniques, in which the light intensity and exposure times 23−26 are controlled, or by employing photolithography. 27,28 More automated and computerized methods such as inkjet printing 29 and "control dipping" 30 have also been described. Gradients have also been generated with various techniques based on surface-confined electrochemistry, using in-plane electrochemical potentials for the reductive desorption of thiol layers, 31−33 corona discharge, 34 scanning electrochemical microscopy, 9,35 and bipolar electrodes.…”