Fibril bending stiffness of 3D collagen matrices instructs spreading and clustering of invasive and non-invasive breast cancer cells.

Extracellular matrix stiffening of breast tissues has been clinically correlated with malignant transformation and poor prognosis. An increase of collagen fibril diameter and lysyl-oxidase mediated crosslinking has been observed in advanced tumor stages. Many current reports suggest that the local mechanical properties of single fibrillar components dominantly regulate cancer cell behavior.

Fibril growth kinetics link buffer conditions and topology of 3D collagen I networks.

Unlabelled: Three-dimensional fibrillar networks reconstituted from collagen I are widely used as biomimetic scaffolds for in vitro and in vivo cell studies. Various physicochemical parameters of buffer conditions for in vitro fibril formation are well known, including pH-value, ion concentrations and temperature. However, there is a lack of a detailed understanding of reconstituting well-defined 3D network topologies, which is required to mimic specific properties of the native extracellular matrix.

Instructing Human Macrophage Polarization by Stiffness and Glycosaminoglycan Functionalization in 3D Collagen Networks.

Dynamic alterations of composition and mechanics of the extracellular matrix are suggested to modulate cellular behavior including plasticity of macrophages (MPhs) during wound healing. In this study, engineered 3D fibrillar matrices based on naturally occurring biopolymers (collagen I, glycosaminoglycans (GAGs)) are used to mimic matrix stiffening as well as modification by sulfated and nonsulfated GAGs at different stages of wound healing. Human MPhs are found to sensitively respond to these microenvironmental cues in terms of polarization toward proinflammatory or wound healing phenotypes over 6 days in vitro.

Surface modification of copolymerized films from three-armed biodegradable macromers - An analytical platform for modified tissue engineering scaffolds.

Unlabelled: The concept of macromers allows for a broad adjustment of biomaterial properties by macromer chemistry or copolymerization. Copolymerization strategies can also be used to introduce reactive sites for subsequent surface modification. Control over surface features enables adjustment of cellular reactions with regard to site and object of implantation.

Molecular weight specific impact of soluble and immobilized hyaluronan on CD44 expressing melanoma cells in 3D collagen matrices.

Unlabelled: Hyaluronan (HA) and its principal receptor CD44 are known to be involved in regulating tumor cell dissemination and metastasis. The direct correlation of CD44-HA interaction on proliferation and invasion of tumor cells in dependence on the molecular weight and the presentation form of HA is not fully understood because of lack of appropriate matrix models. To address this issue, we reconstituted 3D collagen (Coll I) matrices and functionalized them with HA of molecular weight of 30-50kDa (low molecular weight; LMW-HA) and 500-750kDa (high molecular weight; HMW-HA).

Glycosaminoglycan functionalization of mechanically and topologically defined collagen I matrices.

Collagen I and glycosaminoglycans (GAGs) are major components of the extracellular matrix in mammals and widely used for in vitro cell culture matrices. While composition, network microstructure and mechanics of these matrices sensitively determine cell fate, they are hard to adjust independently during matrix reconstitution. We report on a sequential preparation procedure of collagen I matrices, which allows a defined adjustment of network topology and mechanics in combination with GAG functionalization.

Topologically defined composites of collagen types I and V as in vitro cell culture scaffolds.

Cell fate is known to be triggered by cues from the extracellular matrix, including its chemical, biological and physical characteristics. Specifically, mechanical and topological properties are increasingly recognized as important signals. The aim of this work was to provide an easily accessible biomimetic in vitro platform of topologically defined collagen I matrices to dissect cell behaviour under various conditions in vitro.