Open AccessThree-dimensional characterization of collagen remodeling in cell-seeded collagen scaffolds via polarization second harmonic generation
Author(s) -
Dionysios Xydias,
Georgios Ziakas,
Sotiris Psilodimitrakopoulos,
Andreas Lemonis,
Eleni Bagli,
Theodore Fotsis,
Achille Gravanis,
Dimitrios S. Tzeranis,
Emmanuel Stratakis
Publication year - 2021
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.411501
Subject(s) - scaffold , second harmonic generation , umbilical vein , microscopy , materials science , biomedical engineering , fluorescence microscope , 3d cell culture , mesenchymal stem cell , fluorescence , biophysics , tissue engineering , seeding , fluorescence lifetime imaging microscopy , chemistry , in vitro , optics , laser , microbiology and biotechnology , biology , biochemistry , medicine , physics , agronomy
In this study, we use non-linear imaging microscopy to characterize the structural properties of porous collagen-GAG scaffolds (CGS) seeded with human umbilical vein endothelial cells (HUVECs), as well as human mesenchymal stem cells (hMSCs), a co-culture previously reported to form vessel-like structures inside CGS. The evolution of the resulting tissue construct was monitored over 10 days via simultaneous two- and three-photon excited fluorescence microscopy. Time-lapsed 2- and 3-photon excited fluorescence imaging was utilized to monitor the temporal evolution of the vascular-like structures up to 100 µm inside the scaffold up to 10 days post-seeding. 3D polarization-dependent second harmonic generation (PSHG) was utilized to monitor collagen-based scaffold remodeling and determine collagen fibril orientation up to 200 µm inside the scaffold. We demonstrate that polarization-dependent second harmonic generation can provide a novel way to quantify the reorganization of the collagen architecture in CGS simultaneously with key biomechanical interactions between seeded cells and CGS that regulate the formation of vessel-like structures inside 3D tissue constructs. A comparison between samples at different days in vitro revealed that gradually, the scaffolds developed an orthogonal net-like architecture, previously found in real skin.