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Three-dimensional structural niches engineered via two-photon laser polymerization promote stem cell homing

Paper ID Volume ID Publish Year Pages File Format Full-Text
910 69 2013 6 PDF Available
Title
Three-dimensional structural niches engineered via two-photon laser polymerization promote stem cell homing
Abstract

A strategy to modulate the behavior of stem cells in culture is to mimic structural aspects of the native cell/extracellular matrix interaction. We applied femtosecond laser two-photon polymerization (2PP) to fabricate three-dimensional (3-D) microscaffolds, or “niches”, using a hybrid organic–inorganic photoresist called SZ2080. The niches, of sizes fitting in a volume of 100 × 100 × 100 μm3, were made by an external containment grid of horizontal parallel elements and by an internal 3-D lattice. We developed two niche heights, 20 and 80-100 μm, and four lattice pore dimensions (10, 20, 30 μm and graded). We used primary rat mesenchymal stem cells (MSCs) to study cell viability, migration and proliferation in the niches, up to 6 culture days. MSCs preferentially stayed on/in the structures once they ran into them through random migration from the surrounding flat surface, invaded those with a lattice pore dimension greater than 10 μm, and adhered to the internal lattice while the cell nuclei acquired a roundish morphology. In the niches, the highest MSC density was found in those areas where proliferation was observed, corresponding to the regions where the scaffold surface density available for cell adhesion was highest. The microgeometry inducing the highest cell density was 20 μm high with graded pores, in which cell invasion was favored in the central region of large porosity and cell adhesion was favored in the lateral regions of high scaffold surface density. Cell density in the niches, 17 ± 6 cells/(100 × 100 μm2), did not significantly differ from that of the flat surface colonies. This implies that MSCs spontaneously homed and established colonies within the 3-D niches. This study brings to light the crucial role played by the niche 3-D geometry on MSC colonization in culture, with potential implications for the design of biomaterial scaffolds for synthetic niche engineering.

Keywords
Two-photon polymerization; Femtosecond laser; Mesenchymal stem cell; Niche; Scaffold
First Page Preview
Three-dimensional structural niches engineered via two-photon laser polymerization promote stem cell homing
Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 9, Issue 1, January 2013, Pages 4579–4584
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering