Functional consequences of glucose and oxygen deprivation on engineered mesenchymal stem cell-based cartilage constructs

Abstract

(1) Objective Tissue engineering approaches for cartilage repair have focused on the use of mesenchymal stem cells (MSCs). For clinical success, MSCs must survive and produce extracellular matrix in the physiological context of the synovial joint, where low nutrient conditions engendered by avascularity, nutrient utilization, and waste production prevail. This study sought to delineate the role of microenvironmental stressors on MSC viability and functional capacity in 3D culture. (2) Design We evaluated the impact of glucose and oxygen deprivation on the functional maturation of 3D MSC-laden agarose constructs. Since MSC isolation procedures result in a heterogeneous cell population, we also utilized micro-pellet culture to investigate whether clonal subpopulations respond to these microenvironmental stressors in a distinct fashion. (3) Results MSC health and the functional maturation of 3D constructs were compromised by both glucose and oxygen deprivation. Importantly, glucose deprivation severely limited viability, and so compromised the functional maturation of 3D constructs to the greatest extent. The observation that not all cells died suggested there exists heterogeneity in the response of MSC populations to metabolic stressors. Population heterogeneity was confirmed through a series of studies utilizing clonally derived subpopulations, with a spectrum of matrix production and cell survival observed under conditions of metabolic stress. (4) Conclusions Our findings show that glucose deprivation has a significant impact on functional maturation, and that some MSC subpopulations are more resilient to metabolic challenge than others. These findings suggest that pre-selection of subpopulations that are resilient to metabolic challenge may improve in vivo outcomes.

Engineering meniscus structure and function via multi-layered mesenchymal stem cell-seeded nanofibrous scaffolds

“…Since our intention was to capture and quantify changes with different multi-layer configurations, using only three layers allowed us to do so, without introducing additional complicating factors. In the future, it will be critical to test larger, anatomically sized scaffolds to evaluate additional factors, such as nutrient limitations, that could compromise matrix accumulation (Farrell, et al, 2014). Additionally, this study was not powered to provide quantitative data from the histological images, so we did not quantify matrix alignment or fiber/bundle size, although we note that both the fibers within the scaffold and those within the formed collagenous matrix remain quite small.…”

Hypoxic regulation of functional extracellular matrix elaboration by nucleus pulposus cells in long‐term agarose culture

“…38,39 Our own previous work has highlighted the sensitivity of mesenchymal stem cells (MSCs) to glucose concentration, 20 and ongoing work will investigate how glucose availability modulates the biosynthetic properties of both MSCs and NP cells in the context of regenerative therapeutics.…”

“…Percent viability was calculated by counting the number of dead cells (ethidium homodimer-1, red) and live cells (calcein, green) as described previously. 20 …”

Advancing cell therapies for intervertebral disc regeneration from the lab to the clinic: Recommendations of the ORS spine section

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