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A grand challenge of tissue engineering is the fabrication of large constructs with a high density of living cells. By adapting the principles of pick-and-place machines used in the high-speed assembly of electronics, we have developed an innovative instrument, the Bio-Pick, Place, and Perfuse (Bio-P3), which picks up large complex multicellular building parts, transports them to a build area, and precisely places the parts at desired locations while perfusing the parts. These assembled parts subsequently fuse to form a larger contiguous tissue construct. Multicellular microtissues were formed by seeding cells into nonadhesive micro-molds, wherein cells self-assembled scaffold-free parts in the shape of spheroids, toroids, and honeycombs. After removal from the molds, the parts were gripped, transported (using an x, y, z controller), and released using the Bio-P3 with little to no effect on cell viability or part structure. As many as 16 toroids were stacked over a 170 μm diameter post where they fused over the course of 48 h to form a single tissue. Larger honeycomb parts were also gripped and stacked onto a build head that, like the gripper head, provided fluid suction to hold and perfuse the parts during assembly. Scaffold-free building parts help to address several of the engineering and biological challenges to large tissue biofabrication, and the Bio-P3 described in this article is a novel instrument for the controlled gripping, placing, stacking, and perfusing of living building parts for solid organ fabrication.

BACKGROUND: Recent literature suggests that the future of surgeon-scientists in the US has been threatened for the past several decades. However, we documented an overall increase in NIH funding for surgeon-scientists, as well as the number of NIH-funded surgeons, from 2010 to 2020. STUDY DESIGN: NIH-funded principal investigators (PIs) were identified for June 2010 and June 2020 using the NIH internal data platform iSearch Grants (version 2.4). Biographical sketches were searched for key terms to identify surgeon-scientists. Grant research types and total grant costs were collected. American Association of Medical Colleges data were used to determine total surgeon and physician populations. Bivariate chi-square analyses were performed using population totals and were corroborated using z-tests of population proportions using JMP (version 13.0.0). A 2-tailed p value <0.05 was considered significant. RESULTS:In June of 2020, a total of 1,031 surgeon-scientists held $872,456,710 in NIH funding. The percentage of funded surgeons significantly increased from 2010 (0.5%) to 2020 (0.7%) (p < 0.05), and the percentage of funded other physicians significantly decreased from 2.2% in 2010 to 1.6% in 2020 (p < 0.05). All surgeons sustained R grant funding at both time points (58% in 2020 and 60% in 2010), and specifically maintained basic science-focused R grants (73% in 2020 and 78% in 2010). CONCLUSIONS: Our study found surgeon-scientists are increasing in number and NIH funding and are becoming more diverse in their research efforts, while maintaining a focus on basic science.