Spatially controlled cell adhesion on three-dimensional substrates

Abstract

The microenvironment of cells in vivo is defined by spatiotemporal patterns of chemical and biophysical cues. Therefore, one important goal of tissue engineering is the generation of scaffolds with defined biofunctionalization in order to control processes like cell adhesion and differentiation. Mimicking extrinsic factors like integrin ligands presented by the extracellular matrix is one of the key elements to study cellular adhesion on biocompatible scaffolds. By using special thermoformable polymer films with anchored biomolecules micro structured scaffolds, e.g. curved and µ-patterned substrates, can be fabricated. Here, we present a novel strategy for the fabrication of µ-patterned scaffolds based on the “Substrate Modification and Replication by Thermoforming” (SMART) technology: The surface of a poly lactic acid membrane, having a low forming temperature of 60°C and being initially very cell attractive, was coated with a photopatterned layer of poly(L-lysine) (PLL) and hyaluronic acid (VAHyal) to gain spatial control over cell adhesion. Subsequently, this modified polymer membrane was thermoformed to create an array of spherical microcavities with diameters of 300 µm for 3D cell culture. Human hepatoma cells (HepG2) and mouse fibroblasts (L929) were used to demonstrate guided cell adhesion. HepG2 cells adhered and aggregated exclusively within these cavities without attaching to the passivated surfaces between the cavities. Also L929 cells adhering very strongly on the pristine substrate polymer were effectively patterned by the cell repellent properties of the hyaluronic acid based hydrogel. This is the first time cell adhesion was controlled by patterned functionalization of a polymeric substrate with UV curable PLL-VAHyal in thermoformed 3D microstructures.

Biomimetic coating with phosphoserine‐tethered poly(epsilon‐lysine) dendrons on titanium surfaces enhances Wnt and osteoblastic differentiation

“…Some of these proteins display aminoacidic repeats that have been shown to be specifically recognized by integrin dimers (Byron et al 2010). To replicate these adhesion repeats, synthetic polypeptides have been created, such as poly(lysine) (PL), which has been shown to dramatically improve cell adhesion, and it is commonly used to coat plastic culture plates (Lu et al 2009;Zheng et al 2009;Richter et al 2010). Although not directly involved in cell adhesion, phosphoserine (PS) is known to be a potent catalyst of hydroxyapatite formation in living tissues and to enhance the spreading and ALP activities in osteoblast-like cells, including MG-63 and SAOS-2 cell lines (Merolli et al 2006;Santin et al 2006;Bosetti et al 2007).…”

The knee meniscus: Structure–function, pathophysiology, current repair techniques, and prospects for regeneration

“…Both of these approaches are highly relevant to meniscus tissue engineering, but further work is needed to explore these scaffolds in conjunction with meniscus cells. Hydrogel co-cultures may also be created by spatial patterning of different cell types [182-184], using insoluble adhesion molecules or sequential photopolymerization. Fibroblasts have been co-cultured with BMSCs in this manner [183], although the diverse meniscus cell subpopulations have not.…”

Mimicking the biological world: Methods for the 3D structuring of artificial cellular environments

“…In combination with chemical surface treatment, one can create highly complex scaffolds that are spatially attractive for dedicated cell types [50]. In combination with chemical surface treatment, one can create highly complex scaffolds that are spatially attractive for dedicated cell types [50].…”

“…Currently limits are set by the lack of suitable dropon-demand devices, biocompatibility of polymers, and by long process times. Nevertheless, the fusion of different disciplines is [41] Poly(ethyleneoxide terephthalate)-poly (butyleneterephthalate) (PEOT/PBT) copolymers [18] • Multiphoton polymerization of hydrogels/ polymers [42][43][44] -Inkjet printing -Organ printing [15,[45][46][47] Biofunctionalization of 3D substrates Chemical functionalization by patterning [48][49][50][51][52][53] Patterning of hydrogels [16,17,54] Biological application…”

“…Hepatocytes, stem cells [3] Hepatocytes [30] Cartilage [18] Hepatocytes [16], muscle [17], stem cells [50] Stem cells [55,56] moving the artificial recreation of the biological world closer to reality. We now review in detail the strategies in microfluidics and in scaffolding delineated above within the framework of cell cultivation.…”