Biofabrication under fluorocarbon: a novel freeform fabrication technique to generate high aspect ratio tissue-engineered constructs.
Biofabrication under fluorocarbon: a novel freeform fabrication technique to generate high aspect ratio tissue-engineered constructs.
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DOI：
10.1089/biores.2013.0031
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发表时间：
2013-10
影响因子：
--
通讯作者：
Jahnen-Dechent W
中科院分区：
文献类型：
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作者：
Blaeser A;Duarte Campos DF;Weber M;Neuss S;Theek B;Fischer H;Jahnen-Dechent W
生物打印是组织工程的最新发展，它应用快速原型技术来生成复杂的活组织。通常，根据计算机生成的三维模型逐层分配含细胞的水凝胶。打印的水凝胶缺乏机械稳定性阻碍了高纵横比构建体的制造。在这里，我们提出了浸没式生物打印，一种在液体氟碳化合物中自由成型水凝胶的新技术。碳氟化合物的高浮力密度通过漂浮支撑软水凝胶。生成高达30 mm高度的水凝胶构建体。使用3%（w/v）琼脂糖作为水凝胶和一次性注射器针头作为喷嘴，打印机产生的特征直径低至570 μm，横向点胶精度为89 μm。我们打印了薄壁水凝胶圆柱体，高度为4.8 mm，内径为2.9 mm，最小壁厚为2.65 μm。该技术已成功应用于打印动脉分叉模型。我们在碳氟化合物下挤出，细胞化藻酸盐管具有5 mm外径和3 cm长。细胞生长旺盛，在7天的培养期内形成克隆集落。因此，浸没式生物打印似乎特别适合于制造具有高纵横比的中空结构，如用于心血管组织工程的血管移植物以及分支或类血管结构，从而避免了对悬垂突起下方的固体支撑物的需要。
Bioprinting is a recent development in tissue engineering, which applies rapid prototyping techniques to generate complex living tissues. Typically, cell-containing hydrogels are dispensed layer-by-layer according to a computer-generated three-dimensional model. The lack of mechanical stability of printed hydrogels hinders the fabrication of high aspect ratio constructs. Here we present submerged bioprinting, a novel technique for freeform fabrication of hydrogels in liquid fluorocarbon. The high buoyant density of fluorocarbons supports soft hydrogels by floating. Hydrogel constructs of up to 30-mm height were generated. Using 3% (w/v) agarose as the hydrogel and disposable syringe needles as nozzles, the printer produced features down to 570-μm diameter with a lateral dispensing accuracy of 89 μm. We printed thin-walled hydrogel cylinders measuring 4.8 mm in height, with an inner diameter of ∼2.9 mm and a minimal wall thickness of ∼650 μm. The technique was successfully applied in printing a model of an arterial bifurcation. We extruded under fluorocarbon, cellularized alginate tubes with 5-mm outer diameter and 3-cm length. Cells grew vigorously and formed clonal colonies within the 7-day culture period. Submerged bioprinting thus seems particularly suited to fabricate hollow structures with a high aspect ratio like vascular grafts for cardiovascular tissue engineering as well as branching or cantilever-like structures, obviating the need for a solid support beneath the overhanging protrusions.