Advances in three-dimensional cell cultures offer new opportunities in biomedical research and drug development. However, there are still challenges to overcome, including the lack of reliability, repeatability and complexity of tissues obtained by these techniques. In this study, we describe a new bioprinting system called reactive jet impingement (ReJI) for the bioprinting of cell-laden hydrogels. Droplets of gel precursor solutions are jetted at one another such that they meet and react in mid-air before the gel droplets fall to the substrate. This technique offers a combination of deposition rate, cell density and cell viability which is not currently matched by any other bioprinting technique. The importance of cell density is demonstrated in the development of bone microtissues derived from immortalised human bone marrow stem cells. The cells were printed with high viability within a collagen-alginate-fibrin gel, and tissue specific gene expression shows significantly higher tissue maturation rates using the ability of the ReJI system to deposit gels with a high cell density.

中文翻译：

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用于骨微组织制造的高细胞密度凝胶的反应性射流撞击生物打印。

三维细胞培养的进步为生物医学研究和药物开发提供了新的机会。然而，仍有挑战需要克服，包括通过这些技术获得的组织缺乏可靠性、可重复性和复杂性。在这项研究中，我们描述了一种称为反应射流冲击 (ReJI) 的新型生物打印系统，用于对载有细胞的水凝胶进行生物打印。凝胶前体溶液的液滴相互喷射，使得它们在凝胶液滴落到基材之前在半空中相遇并反应。该技术提供了沉积速率、细胞密度和细胞活力的组合，这是目前任何其他生物打印技术都无法比拟的。细胞密度的重要性在源自永生化人骨髓干细胞的骨微组织的发育中得到证实。