The 4D-printing technology is applied to fabricate a shape memory peripheral stent with good biocompatibility, which sustains long-term drug release. The star polymer s-PCL is prepared by ring opening polymerization of -caprolactone with the -OH of -cyclodextrin ( CD) as initiator, and then the s-PCL is modified with acrylate endgroup which allows the polymerization under UV light to form the crosslinking network c-PCL. Attributed to the feature of the high crosslinked structure and chemical nature of polycaprolactone (PCL) and CD, the composite exhibits appropriate tensile strength and sufficient elasticity and bursting pressure, and it is comparable with great saphenous vein in human body. The radial support of the 4D-printed stent is 0.56 ± 0.11 N and is equivalent to that of commercial stent. The cell adhesion and proliferation results show a good biocompatibility of the stent with human umbilical vein endothelial cells. Due to the presence of CD, the wettability and biocompatibility of the materials are improved, and the sustained paclitaxel release based on the host-guest complexion shows the potential of the drug-loaded stent for long-term release. This study provides a new strategy to solve the urgent need of small-diameter scaffolds to treat critical limb ischemia.

Self-rolling allows the bilayer to transform into a 3D structure in response to specific external stimulation, such as heat, humidity, ions, etc. Herein, we report a 4D printing bilayer with a top sodium alginate layer and bottom polycaprolactone layer that could be rolled up to a tubular structure upon exposure to heat and Ca 2+ solution stimulation. The discrepancy in the swelling and thermal-responsiveness between alginate and polycaprolactone induced the self-rolling under different stimuli. The self-rolling behavior of the bilayer depends on the aspect ratio, thickness ratio of the bilayer film, the pattern, and external stimuli. Thus, a tailorable surface of the self-rolled tube was obtained by tuning the bilayer parameter and the stimuli medium to meet varied demands. This controllable shape changing provides a strategy for the preparation of well-defined tubular structures. Besides, the biocompatibility of bilayer film suggests the potential application in the field of biomedical device such as vascular stent.