A bioinspired 4D printed hydrogel capsule for smart controlled drug release. (June 2022)

• Record Type: Journal Article
• Authors: Zu, S.; Wang, Z.; Zhang, S.; Guo, Y.; Chen, C.; Zhang, Q.; Wang, Z.; Liu, T.; Liu, Q.; Zhang, Z.
• Is Part Of: Materials today chemistry. Volume 24(2022)
• Publication Date: 2022-06
• Subjects: 4D printing -- Controlled release -- Drug delivery -- Macroporous hydrogels -- Poly(N-isopropylacrylamide) (PNIPAM); Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2022.100789
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: With the ever-increasing demands for personalized drugs, disease-specific and condition-dependent drug delivery systems, four-dimensional (4D) printing can be used as a new approach to develop drug capsules that display unique advantages of self-changing drug release behavior according to the actual physiological circumstances. Herein, a plant stomata-inspired smart hydrogel capsule was developed using an extrusion-based 4D printing method, which featured with UV cross-linked poly(N-isopropylacrylamide) (PNIPAM) hydrogel as the capsule shell. The lower critical solution temperature (LCST) of the PNIPAM hydrogels was approximately 34.9 °C and macroporous PNIPAM hydrogels were prepared with higher molecular weight polyethylene glycols (PEGs) as the pore-forming agents. Owing to the LCST-induced shrinking/swelling properties, the prepared PNIPAM hydrogel capsules exhibited temperature-responsive drug release along with the microstructure changes in the PNIPAM hydrogels. The in vitro drug release test confirmed that the PNIPAM hydrogel capsules can autonomously control their drug release behaviors on the basis of ambient temperature changes. Moreover, the increased PEG molecular weights in the macroporous PNIPAM hydrogel capsules caused an obvious improvement of drug release rate, distinctly indicating that the drug release profiles can be well programmed by adjusting the internal pore size of the hydrogel capsules. In vitro biocompatibility studies confirmed that the PNIPAM hydrogel capsules have great potential for biomedical applications. The bioinspired 4D printed hydrogel capsules pioneer the paradigm of smart controlled drug release. Graphical abstract: Image 1 Highlights: Through a 4D printing method to produce bioinspired hydrogel capsules for smart controlled drug release. The 4D printed capsules featured with PNIPAM hydrogel as the shell, and the types and doses of drugs can be freely loaded. Drug release profiles can be well programmed by adjusting the internal pore size of the hydrogel capsules. In contrast to common 4D external shape change, we used 4D printing to produce change in internal material structure.