02440nas a2200373   4500000000100000000000100001008004100002260000900043653001900052653002200071653002300093653001600116653001400132653002100146653002000167100001500187700001600202700001700218700001400235700002000249700001700269700002300286700002400309700002900333700002200362700002100384700001700405245011700422856006700539300001200606490000700618520142700625022001402052       2024                            d  c202410a3D bioprinting10acancer metastasis10adirect ink writing10aorgan model10aperfusion10asacrificial-free10avascularization1 aDongwei Wu1 aShumin Pang1 aJohanna Berg1 aYikun Mei1 aAhmed S. M. Ali1 aViola Röhrs1 aBeatrice Tolksdorf1 aJudith Hagenbuchner1 aMichael J. Ausserlechner1 aHedwig E. Deubzer1 aAleksander Gurlo1 aJens Kurreck00aBioprinting of Perfusable Vascularized Organ Models for Drug Development via Sacrificial-Free Direct Ink Writing  uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202314171  a23141710 v343 a3D bioprinting enables the fabrication of human organ models that can be used for various fields of biomedical research, including oncology and infection biology. An important challenge, however, remains the generation of vascularized, perfusable 3D models that closely simulate natural physiology. Here, a novel direct ink writing (DIW) approach is described that can produce vascularized organ models without using sacrificial materials during fabrication. The high resolution of the method allows the one-step generation of various sophisticated hollow geometries. This sacrificial-free DIW (SF-DIW) approach is used to fabricate hepatic metastasis models of various cancer types and different formats for investigating the cytostatic activity of anti-cancer drugs. To this end, the models are incorporated into a newly developed perfusion system with integrated micropumps and an agar casting step that improves the physiological features of the bioprinted tissues. It is shown that the hepatic environment of the tumor models is capable of activating a prodrug, which inhibits breast cancer growth. This versatile SF-DIW approach is able to fabricate complicated perfusable constructs or microfluidic chips in a straightforward and cost-efficient manner. It can also be easily adapted to other cell types for generating vascularized organ tissues or cancer models that may support the development of new therapeutics.  a1616-3028