Coaxial bioprinting of hydrogel tubes has tremendous potential in the fabrication of highly complex large-scale vascularized structures, however, constructs with bioinks of simultaneous weak printability and perfusable networks have not been reported. Here, we report a coaxial printing method in which double-channel filaments are three-dimensional (3D) extrusion-bioprinted using a customized dual-core coaxial nozzle. The filament in one channel can perform core/shell role and the other channel can play a role in perfusion. These parallel channels within filaments are separated by an interval wall of alginate, whose thickness (∼50 μm) is beneficial to supplement nutrients via perfusion. Different cell-laden hydrogels of weak mechanics were used to test the adaptability and perfusability of our method, and the results showed that dynamic perfusion maintained higher viability and functions than static culture. By combining with a bioprinter, 8-layer perfusable double-channel constructs were fabricated, and the cell viabilities gradually decreased with the reduction in nutrients and oxygen in the downstream medium. Furthermore, the double-channel filaments were tested as a platform to mimic dynamic functions between cells through sequential perfusion by using Mouse insulinoma 6 (Min6) and Hepatocellular carcinoma (HepG2) as the model cells. These results demonstrated the insulin secreted by Min6 upstream simulated and increased the uptake of glucose by the downstream HepG2 cells. In conclusion, our study provided evidence for the probability of all-in-one fabrication of 3D double-channel perfusable constructs with high simplicity, expansibility, and versability. Our strategy has significant potential for building large-scale tissue constructs for applications in tissue engineering, possibly even in drug screening and regenerative medicine.

Two new abietane diterpenoids, phlecarinatone A (1) and phlecarinatone B(2), along with two known analogues (3 and 4), were isolated from Phlegmariurus carinatus. The structures of 1−4 were unambiguously elucidated by comprehensive spectroscopic analyses. Abietane diterpenoids were isolated from the plant for the first time. All isolates were tested in vitro for their neuroprotective activities, and compound 2 showed moderate effect at the concentrations ranging from 5~20 μM.

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Aptamer-drug conjugate has been developed as a potential class of targeted therapeutics, which using aptamer as tumor recognition elements could targeted deliver the conjugated chemically toxic drug to tumor site. One of the keys to the success of aptamer-drug conjugate is terminal modification of aptamer to facilitate the conjugation with drugs. Herein, a novel terminal amino-modified nucleolin aptamer which using solketal as raw material was developed. Moreover, its paclitaxel conjugate wherein the aptamer coupled with paclitaxel derivatives by amidation was also conducted. The easily available raw materials, stable structure, together with its simplicity of operation, gives it the potential for use on an industrial scale.