Characterization of microfluidic human epidermal keratinocyte culture

Abstract

Human epidermal keratinocytes (HEK) are skin cells of primary importance in maintaining the body's defensive barrier and are used in vitro to assess the irritation potential and toxicity of chemical compounds. Microfluidic systems hold promise for high throughput irritant and toxicity assays, but HEK growth kinetics have yet to be characterized within microscale culture chambers. This research demonstrates HEK patterning on microscale patches of Type I collagen within microfluidic channels and maintenance of these cells under constant medium perfusion for 72 h. HEK were shown to maintain 93.0%-99.6% viability at 72 h under medium perfusion ranging from 0.025-0.4 ll min -1 . HEK maintained this viability while *100% confluent-a level not possible in 96 well plates. Microscale HEK cultures offer the ability to precisely examine the morphology, behavior and viability of individual cells which may open the door to new discoveries in toxicological screening methods and wound healing techniques.

A Review of the Role of Mechanical Forces in Cutaneous Wound Healing

“…Microfluidic channels are an emerging technology [130,131] that will allow for the precision delivery of cytokines, growth factors and even cells in response to changes sensed within a wound microenvironment. Smart biomaterials including biodegradable matrices (cell delivery vehicles) and biogels that integrate into a healing wound and recruit endogenous stem cells from local reservoirs to the site of injury show much promise.…”

In vitro skin three-dimensional models and their applications

“…Hence, all systems have a perfusion whereby shear stress is produced which in turn increases cell viability and proliferation in contrast to static cultures [68]. Additionally, almost all systems offer an air-liquid-interface culture [69].…”

“…Additionally, almost all systems offer an air-liquid-interface culture [69]. Depending on the application, either skin biopsies, primary cells or cell lines can be used [66,68,69]. Also, human induced pluripotent stem cells provide a source to mimic healthy and diseased skin models as they can be differentiated into keratinocytes [70], fibroblasts [71], melanocytes [72] and endothelial cells [67].…”

From Microscale Devices to 3D Printing

“…Studies using these cells may lead to the development of personalized ‘humans-on-chips’ systems with all cellular components derived from a patient. Over the past decade researchers have constructed organ-on-chip model systems for studying functions of different organs including kidney 10–13 , intestine 14, 15 , lung, 16–18 , liver 19–23 , heart 9, 24, 25 , smooth and striated muscle tissue 26 , fat 27–29 , bone 30 , marrow 29, 31 , cornea 32 , skin 33 , blood vessels 34–36 , nerves 37, 38 and even blood-brain barrier 39, 40 . However, due to the single cell type composition, many of the above systems cannot be considered organ models.…”