In 3D (bio)printing, it is critical to optimize the printing conditions to obtain scaffolds with designed structures and good uniformities. Traditional approaches for optimizing the parameters oftentimes rely on the prior knowledge of the operators and tedious optimization experiments, which can be both time‐consuming and labor‐intensive. Moreover, with the rapid increase in the types of biomaterial inks and the geometrical complexities of the scaffolds to be fabricated, such a traditional strategy may prove less effective. To address the challenge, an artificial intelligence‐assisted high‐throughput printing‐condition‐screening system (AI‐HTPCSS) is proposed, which is composed of a programmable pneumatic extrusion (bio)printer and an AI‐assisted image‐analysis algorithm. Based on the AI‐HTPCSS, the printing conditions for obtaining uniformly structured hydrogel architectures are screened in a high‐throughput manner. The results show that the scaffolds printed under the optimized conditions demonstrate satisfying mechanical properties, in vitro biological performances, and efficacy in accelerating the diabetic wound healing in vivo. The unique AI‐HTPCSS is expected to offer an enabling platform technology on streamlining the manufacturing of tissue‐engineering scaffolds through 3D (bio)printing techniques in the future.
Tumor on a Chip
In article number 2200758, Lu Huang and co‐workers propose a pathomimetic colorectal tumor‐on‐a‐chip (CRT‐chip) that can effectively recapitulate the in vivo dynamic physiology and pathology of primary colorectal cancer (CRC). The cover figure demonstrates the analogy between the CRT‐chips and the in vivo primary CRC. The central channel seeded with epithelial cells mimics the epithelium layer of colorectum. The tumor cells loaded in the microchamber emulate the site‐specific primary CRC. The bottom channel underneath the microchamber recapitulates the in vivo tumor vessels.
Microbubbles
have been widely used as ultrasound contrast agents
in clinical diagnosis. Moreover, most current preparation methods
for microbubbles are uncontrollable, and the as-obtained microbubbles
are unstable in aqueous solution or under ultrasound. Here, we report
a strategy to prepare superiorly stable microbubbles with three-layer
structures by the ethanol–water exchange. This versatile method
can also be applied to prepare different kinds of protein microbubbles
with various sizes for advanced biomedical applications. To demonstrate
this, the protein air microbubbles are created, which is stable in
water for several days with intact structures and exhibits excellent
contrast-enhanced ultrasound imaging. Moreover, the protein air microbubbles
can also deliver a mass of drugs while maintaining their stable structures,
making them a platform for ultrasound imaging-guided drug delivery.
The versatile protein air microbubbles have great potential for the
design and application of theranostic platforms.
The development of an in vitro colorectal cancer (CRC) model that reconstructs the physiopathological microenvironment of human colorectal cancer shows great potential in accelerating the study of CRC mechanisms and the development of anti-CRC drugs. To this end, a pathomimetic colorectal tumor-on-a-chip (CRT-chip) that can effectively recapitulate the in vivo dynamic physiology and pathology of primary CRC is proposed. It not only allows controllable seeding and cultivation of CRC cells to emulate the site-specific occurrence of primary CRC, but also provides continuous low-speed flows and peristalsis-like deformation on colorectum epithelium to simulate the fluid shearing and peristalsis in human colorectum. Moreover, a channel that transports nutrients to CRC cells is designed specifically to mimic the function of tumor vessels. Based on the pathomimetic CRT-chip, the therapeutic effect of a photothermal anticancer drug was tested and quantified, exhibiting its great potentials in in vitro evaluation of anti-CRC drugs.
Cell-laden hydrogel microstructures have been used in broad applications in tissue engineering, translational medicine, and cell-based assays for pharmaceutical research. However, the construction of cell-laden hydrogel microstructures in vitro remains challenging. The technologies permitting generation of multicellular structures with different cellular compositions and spatial distributions are needed. Herein, we propose a laser-guided programmable hydrogel-microstructures-construction platform, allowing controllable and heterogeneous assembly of multiple cellular spheroids into spatially organized multicellular structures with good bioactivity. And the cell-laden hydrogel microstructures could be further leveraged for in vitro drug evaluation. We demonstrate that cells within hydrogels exhibit significantly higher half-maximal inhibitory concentration values against doxorubicin (DOX) compared with traditional 2D plate culture. Moreover, we reveal the differences in drug responses between heterogeneous and homogeneous cell-laden hydrogel microstructures, providing valuable insight into in vitro drug evaluation.
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