Long-term vascular contractility assay using genipin-modified muscular thin films

Abstract

Vascular disease is a leading cause of death globally and typically manifests chronically due to long-term maladaptive arterial growth and remodeling. To date, there is no in vitro technique for studying vascular function over relevant disease time courses that both mimics in vivo-like tissue structure and provides a simple readout of tissue stress. We aimed to extend tissue viability in our muscular thin film contractility assay by modifying the polydimethylsiloxane (PDMS) substrate with micropatterned genipin, allowing extracellular matrix turnover without cell loss. To achieve this, we developed a microfluidic delivery system to pattern genipin and extracellular matrix proteins on PDMS prior to cell seeding. Tissues constructed using this method showed improved viability and maintenance of in vivo-like lamellar structure. Functional contractility of tissues fabricated on genipin-modified substrates remained consistent throughout two weeks in culture. These results suggest that muscular thin films with genipin-modified PDMS substrates are a viable method for conducting functional studies of arterial growth and remodeling in vascular diseases.

Vascular smooth muscle cell functional contractility depends on extracellular mechanical properties

“…Thus, it is important to recapitulate in vivo structure to study VSMC function in vitro. W e have previously developed vascular muscular thin film (vMTF) (Alford et al, 2010) technology to evaluate VSMC stress generation in aligned, confluent vascular lamellae mimics, but to date all vMTF studies have been performed with a single substrate modulus (Alford et al, 2011a; Alford et al, 2011b; Hald et al, 2014; Win et al, 2014). Thus, it is unclear how extracellular mechanical properties affect contractile function in confluent VSMCs with in vivo -like structure.…”

Microfluidic Genipin Deposition Technique for Extended Culture of Micropatterned Vascular Muscular Thin Films

“…Using deposition of genipin onto PDMS substrates, we have demonstrated extended cell viability and maintenance of vascular smooth muscle function over two weeks. This is a significant improvement over previous fabrication techniques, which can lead to delamination of tissues and cell death after 4 -7 days in culture 19 , and may aid development of more robust artery-on-a-chip methods. Due to the chronic nature of most vascular diseases, this advance provides the framework for a variety of future investigations into the contractile mechanisms involved in specific vascular pathologies.…”

Microfluidic Organ/Body-on-a-Chip Devices at the Convergence of Biology and Microengineering

“…As soon as the vascular component of the cardiovascular system is taken into account, reproducing the complexity of the system itself becomes more and more challenging. Several research groups are interested in the development of microfluidic devices in which angiogenesis [ 58 , 59 ], artery structure [ 68 ] and network [ 69 ], vascular endothelial function [ 70 ] growth and remodeling [ 71 ] can be studied. More directed to vascular pathologies, other groups are focused in highlighting vaso‑occlusive processes [ 72 ] ( Figure 1 A) and thrombosis [ 73 ], evaluating hypertensive micro vessels [ 74 ] and antihypertensive drug effects [ 65 ], or studying long-term vascular contractility [ 71 ].…”