Thick-tissue bioreactor as a platform for long-term organotypic culture and drug delivery

Abstract

We have developed a novel, portable, gravity-fed, microfluidics-based platform suitable for optical interrogation of long-term organotypic cell culture. This system is designed to provide convenient control of cell maintenance, nutrients, and experimental reagent delivery to tissue-like cell densities housed in a transparent, low-volume microenvironment. To demonstrate the ability of our Thick-Tissue Bioreactor (TTB) to provide stable, long-term maintenance of high-density cellular arrays, we observed the morphogenic growth of human mammary epithelial cell lines, MCF-10A and their invasive variants, cultured under three-dimensional (3D) conditions inside our system. Over the course of 21 days, these cells typically develop into hollow “mammospheres” if cultured in standard 3D Matrigel. This complex morphogenic process requires alterations in a variety of cellular functions, including degradation of extracellular matrix that is regulated by cell-produced matrix proteinases. For our “drug” delivery testing and validation experiments we have introduced proteinase inhibitors into the fluid supply system, and we observed both reduced proteinase activity and inhibited cellular morphogenesis. The size inhibition results correlated well with the overall proteinase activities of the tested cells.

Advances in multicellular spheroids formation

“…It has been documented that this micro moulding method can significantly reduce consumption of reagents, create desired concentration gradients of growth/signal factors and nutrients, allow high-density culture at a high cell-to-fluid volume ratio and decrease shear stress under the laminar condition in micro-scale structures [111]. Du et al [112] proposed a method to fabricate different micro-scale structures with PEG-based cell laden hydrogels to form MCSs from NIH 3T3 mouse fibroblasts.…”

“…A portable bioreactor was developed to maintain a sterile microenvironment and sustain cell growth, maturation and organ formation [111]. MCF-AT1 cells were encapsulated into the Matrigel that is placed at the bottom part of the PDMS bioreactor.…”

Towards personalized computational oncology: from spatial models of tumour spheroids, to organoids, to tissues

“…Additionally, microfluidics can provide a wide range of physical and chemical stimuli through precise control of the shear stresses and flow switching [162,163]. Unlike animal model systems, most microfluidic devices are fabricated from optically transparent materials that permit visualization of various cellular processes (sometimes in real time) through bright field and fluorescent imaging [164,165]. The choice of softer fabrication materials offers further control of such mechanical stresses as tension or compression.…”

“…These microphysiological systems are capable of maintaining live cultures for weeks and even months and can replicate complex organ environments, including 3D multicellular organ structures, nutrient supply and waste removal, oxygenation states, interstitial flows and a variety of microenvironmental gradients [163,165]. These systems are composed of individually addressable micro-compartments to permit precise regulation of a specific organ layer or tissue area and individualized tissue perfusion [166,167].…”

Programming microphysiological systems for children’s health protection

“…Mammary microbioreactors, hollow mammospheres coupled with microfluidics, provide novel research models to probe disease pathways in a human system. 26 Mammosphere formation requires diverse cellular functions, including extracellular matrix remodeling. Introducing various drugs/chemicals into the fluid supply system provides an approach to probe a developmental response to chemicals such as endocrine disrupters that may increase the risk of breast cancer and other disease outcomes dependent on the timing of exposure.…”