4D bioprintable self-healing hydrogel with shape memory and cryopreserving properties. (27th September 2021)

• Record Type: Journal Article
• Authors: Wu, Shin-Da; Hsu, Shan-hui
• Is Part Of: Biofabrication. Volume 13:Number 4(2021)
• Publication Date: 2021-09-27
• Subjects: 4D bioprinting -- biodegradable polyurethane -- self-healing -- shape memory -- cryopreservation; Biomedical engineering -- Periodicals; Tissue engineering -- Periodicals; Biomedical materials -- Microstructure -- Periodicals; Bioengineering -- Periodicals; 610.28
• DOI: 10.1088/1758-5090/ac2789
• Languages: English
• ISSNs: 1758-5082

Abstract

Abstract: Four-dimensional (4D) bioprinting is an emerging biofabrication technology that integrates time as a fourth dimension with three-dimensional (3D) bioprinting for fabricating customizable tissue-engineered implants. 4D bioprinted implants are expected to possess self-healing and shape memory properties for new application opportunities, for instance, fabrication of devices with good shape integrity for minimally invasive surgery. Herein, we developed a self-healing hydrogel composed of biodegradable polyurethane (PU) nanoparticles and photo-/thermo-responsive gelatin-based biomaterials. The self-healing property of hydrogel may be associated with the formation of reversible ionomeric interaction between the COO − group of PU nanoparticles and NH3 + group on the gelatin chains. The self-healing hydrogel demonstrated excellent 3D printability and filament resolution. The UV-crosslinked printed hydrogel showed good stackability (>80 layers), structural stability, elasticity, and tunable modulus (1−60 kPa). The shape-memorizable 4D printed constructs revealed good shape fixity (∼95%) and shape recovery (∼98%) through the elasticity as well as forming and collapsing of water lattice in the hydrogel. The hydrogel and the printing process supported the continuous proliferation of neural stem cells (NSCs) (∼3.7-fold after 14 days). Moreover, the individually bioprinted NSCs and mesenchymal stem cells in the adjacent, self-healed filaments showed mutual migration and such interaction promoted the cell differentiation behavior. The cryopreserved (−20 °C or −80 °C) 4D bioprinted hydrogel after awakening and shape recovery at 37 °C demonstrated cell proliferation similar to that of the non-cryopreserved control. This 4D bioprintable, self-healable hydrogel with shape memory and cryopreserving properties may be employed for customized biofabrication.