Nguyen, Kianna M

This review describes approaches for encapsulation of pluripotent stem cells, the biomaterials used, strategies for differentiation into hepatocytes and β cells, and the impact of microencapsulation on cellular therapy.

Human pluripotent stem cells (hPSCs) are capable of unlimited proliferation and can undergo differentiation to give rise to cells and tissues of the three primary germ layers. While directing lineage selection of hPSCs has been an active area of research, improving the efficiency of differentiation remains an important objective. In this study, we describe a two-compartment microfluidic device for co-cultivation of adult human hepatocytes and stem cells. Both cell types were cultured in a 3D or spheroid format. Adult hepatocytes remained highly functional in the microfluidic device over the course of 4 weeks and served as a source of instructive paracrine cues to drive hepatic differentiation of stem cells cultured in the neighboring compartment. The differentiation of stem cells was more pronounced in microfluidic co-cultures compared to a standard hepatic differentiation protocol. In addition to improving stem cell differentiation outcomes, the microfluidic co-culture system described here may be used for parsing signals and mechanisms controlling hepatic cell fate.

Background: Concern exists that the clinical trial populations differ from respective cancer populations in terms of their age distribution affecting the generalizability of the results, especially in underrepresented minorities. We hypothesized that the clinical trials that do not report race are likely to suffer from a higher degree of age disparity. Methods: Food and Drug Administration (FDA) drug approvals from July 2007 to June 2019 were reviewed to identify oncology approvals, and trials with age details were selected. The outcomes studied were the weighted mean difference in age between the clinical trial population and real-world population for various cancers, the prevalence of race reporting and association of age and race reporting with each other. Results: Of the 261 trials, race was reported in 223 (85.4%) of the trials, while 38 trials (14.6%) had no mention of race. Race reporting improved minimally over time: 29 (85.3%) in 2007–2010 vs. 49 (80.3%) in 2011–2014 vs. 145 (85.4%) during the period 2015–2019 (p-value = 0.41). Age discrepancy between the clinical trial population and the real-world population was higher for studies that did not report race (mean difference −8.8 years (95% CI −12.6 to −5.0 years)) vs. studies that did report it (mean difference −5.1 years, (95% CI −6.4 to −3.7 years), p-value = 0.04). Conclusion: The study demonstrates that a significant number of clinical trials leading to cancer drug approvals suffer from racial and age disparity when compared to real-world populations, and that the two factors may be interrelated. We recommend continued efforts to recruit diverse populations.