Biomaterial-driven lymphangiogenesis using click-crosslinked gelatin hydrogels
File(s)
Author(s)
E. Al-Ansari, Dana
Type
Thesis
Abstract
Lymphatic vessels play a crucial role in maintaining tissue fluid balance and immune function. Despite advances in understanding the mechanisms driving lymphangiogenesis, most studies use conventional two-dimensional cell cultures, which limit cell migration and adhesion. In contrast, three-dimensional (3D) cell cultures can replicate the tissue microenvironment by enhancing cell–extracellular matrix (ECM) interactions. Here, I established a 3D lymphangiogenesis model using bioorthogonal click-crosslinked gelatin hydrogels (GelTN).
GelTN’s physico-mechanical properties were tailored to closely mimic the endothelium’s elastic modulus, testing a range of 1.2 – 6 kPa. A spheroid-based lymphangiogenesis assay was developed to model cell–ECM interactions in a physiologically relevant 3D environment. The model was further advanced to include dynamic mechanical stimulation using a custom-built uniaxial cell-stretcher device, to model cardiac lymphatics. Additionally, GelTN’s potential in promoting in vivo lymphangiogenesis was demonstrated through its injectability and ability to sustain the release of vascular endothelial growth factor – C (VEGF-C) in a mouse model.
The tunable properties of GelTN allowed for the identification of key factors that influence lymphatic endothelial cell (LEC) sprouting in response to matrix stiffness. This robust platform was utilised in various in vitro applications, including the study of genetic variants in lymphangiogenesis by modelling lymphoedema patient-derived endothelial colony-forming cells, or LEC following siRNA gene inhibition. Additionally, GelTN was shown to sustain the release of VEGF-C for up to three weeks and support neo-vessel formation following subcutaneous injection in vivo. A dynamic model of lymphangiogenesis was optimised to replicate cardiac lymphatics, although future studies will be required to refine the assay to fully elucidate the effects of GelTN cyclic stretch on LEC mechanosensitive genes. Overall, these findings underscore the potential of GelTN as a valuable tool in both basic research and clinical applications, particularly in tissue engineering and regenerative medicine.
GelTN’s physico-mechanical properties were tailored to closely mimic the endothelium’s elastic modulus, testing a range of 1.2 – 6 kPa. A spheroid-based lymphangiogenesis assay was developed to model cell–ECM interactions in a physiologically relevant 3D environment. The model was further advanced to include dynamic mechanical stimulation using a custom-built uniaxial cell-stretcher device, to model cardiac lymphatics. Additionally, GelTN’s potential in promoting in vivo lymphangiogenesis was demonstrated through its injectability and ability to sustain the release of vascular endothelial growth factor – C (VEGF-C) in a mouse model.
The tunable properties of GelTN allowed for the identification of key factors that influence lymphatic endothelial cell (LEC) sprouting in response to matrix stiffness. This robust platform was utilised in various in vitro applications, including the study of genetic variants in lymphangiogenesis by modelling lymphoedema patient-derived endothelial colony-forming cells, or LEC following siRNA gene inhibition. Additionally, GelTN was shown to sustain the release of VEGF-C for up to three weeks and support neo-vessel formation following subcutaneous injection in vivo. A dynamic model of lymphangiogenesis was optimised to replicate cardiac lymphatics, although future studies will be required to refine the assay to fully elucidate the effects of GelTN cyclic stretch on LEC mechanosensitive genes. Overall, these findings underscore the potential of GelTN as a valuable tool in both basic research and clinical applications, particularly in tissue engineering and regenerative medicine.
Version
Open Access
Date Issued
2024-08-22
Date Awarded
01/10/2024
License URL
Advisor
Birdsey, Graeme
Celiz, Adam
Sponsor
Qatar Research, Development and Innovation
Grant Number
WHCV_I26030
Publisher Department
National Heart & Lung Institute
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)