Introduction

Stroke and cerebral small vessel disease (CSVD) are major causes of death and disability worldwide. Cerebral Small Vessel Disease is a group of conditions that affects the stability of cerebral micro-vessels, manifesting in a variety of clinical syndromes, including vascular cognitive impairment, dementia, and stroke.  CSVD accounts for a quarter of the 12 million global stroke cases, and ~45% of the 35–42 million new cases of dementia each year (Bos et al, 2018). Despite the world-wide importance of CSVD and stroke there are no current treatments beyond risk factor modification and restoration of blood flow. A major barrier to developing new therapies is a lack of relevant human in vitro models that capture the form and function of brain blood vessels. Our lab is developing new models of both stroke and CSVD that enable the study of cerebral blood vessel function and dysfunction.

Aims

To develop a suit of microfluidic cell culture models that replicate blood vessel dysfunction in CSVD and stroke.

Methods

We have used soft-lithography micro-fabrication techniques to produce microfluidic cell culture devices that can pattern a cell laden hydrogel and stimulate vasculogenesis to create a capillary network mimetic. To model stroke, human primary brain endothelial cells, pericytes and astrocytes were co-cultured and allowed to form vessel like structures before being subjected to oxygen glucose deprivation. Vessel integrity was measured using fluorescent tracer dyes. For CSVD models, induced pluripotent stem cells were derived from patients with monogenic forms of CSVD and differentiated to endothelial cells, pericytes and astrocytes for co-culture in microfluidic devices. Barrier integrity of the resulting in vitro vessels was measured using fluorescent tracers and compared to isogenic disease corrected controls.

Results

Both stroke mimicking conditions and CSVD causing mutations disrupted barrier function of in vitro brain capillary networks.

Conclusions

Microfluidic cell culture approaches can be used to create brain capillary mimetics that recapitulate barrier disruption relating to stroke and CSVD.