Porous yet dense matrices: using ice to shape collagen 3D cell culture systems with increased physiological relevance

Abstract

Standard in vitro cell culture is one of the pillars of biomedical science. However, there is increasing evidence that 2D systems provide biological responses that are often in disagreement with...

Circulating Tumor Cells in Cancer Diagnostics and Prognostics by Single-Molecule and Single-Cell Characterization

“…Recently, synthetic polymer-based materials produced via ice templating were used to reproduce bone tissue and model osteosarcoma cell colonization and proliferation, which highlighted the influence of substrate stiffness on cell behavior . Recent results have shown that freeze-casting can be adapted to develop macroporous fibrillar collagen-based materials which are suitable for use in the 3D cell culture of normal human dermal fibroblasts (NHDFs) . This scalable system combines the macroscale control over the porosity of type I collagen with the accurate reproduction of the subtle architectures of the ECM.…”

“…Among these techniques is freeze-casting (also known as ice templating or directional freezing). This fabrication strategy, which was initially used to prepare lightweight ceramic materials, has gained attention as a novel approach to produce macroporous bioinspired and biomimetic materials. − The composition, morphological features (pore size and morphology, wall thickness), and mechanics of these materials are controllable and can be adapted for cell culture. − The technique is based on growing an oriented freezing front inside a naturally derived or synthetic polymer solution induced by a controlled temperature gradient. The phase segregation caused by controlled ice growth, followed by lyophilization, results in a macroporous ordered structure that reproduces the structural and mechanical properties of natural materials .…”

“…90 Recent results have shown that freeze-casting can be adapted to develop macroporous fibrillar collagen-based materials which are suitable for use in the 3D cell culture of normal human dermal fibroblasts (NHDFs). 85 This scalable system combines the macroscale control over the porosity of type I collagen with the accurate reproduction of the subtle architectures of the ECM. Although no explicit examples are nowadays available for the culture of CTCs using scaffolds obtained via freeze casting, the technique constitutes an exciting alternative for the elaboration of new materials relevant for ex vivo propagation of CTCs.…”

Innovative Approaches and Advances for Hair Follicle Regeneration

“…Pfizer’s Gelfoam Absorbable Collagen Sponge USP is a sterile collagen sponge on which human hair follicles at various stages of growth are tissue cultured and produce hair follicle-associate-pluripotent stem cells with hair follicle-derived hair stems . An appropriate concentration of human DPCs or dermal sheath cells can be added to the interior of the gel to form “a gel containing cells” as type I collagen can facilitate the production of a porous but dense sponge that accelerates cell migration and nutrient exchange, and therefore, the dense collagen wall can mimic the ECM well locally . The dermal equivalent structures obtained from human neonatal foreskin keratinocytes that contain DPCs expressed the human DPC-specific protein versican on type I collagen gel scaffolds.…”

“…140 An appropriate concentration of human DPCs or dermal sheath cells can be added to the interior of the gel to form "a gel containing cells" as type I collagen can facilitate the production of a porous but dense sponge that accelerates cell migration and nutrient exchange, and therefore, the dense collagen wall can mimic the ECM well locally. 141 The dermal equivalent structures obtained from human neonatal foreskin keratinocytes that contain DPCs expressed the human DPCspecific protein versican on type I collagen gel scaffolds. Moreover, the epithelial and dermal cells in the vicinity of the new HFs are of human origin with a complete structure of bulb, dermal sheath, hair stroma, and cortex.…”