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International Journal of Bioprinting 3D printing of smart constructs for precise medicine

A C

B
D

E F

G H I

Figure 6. Potential applications of stimuli-responsive bioinks for tissue regeneration and repair. (A) AA-MA tube responsiveness in immersed solutions
and tube diameters according to printing speed. (B) Representative fluorescent images of cell-laden AA-MA tubes for 7 days: fluorescence images in green
(upper row) representing live cells, fluorescence images in red (middle row) showing dead cells within self-folded tubes, and overlays of green and red
fluorescence images (lower row) with live cells (orange) and dead cells (red) [152] . (Figure A and B reproduced with permission from Kirillova et al. [152] ;
copyright 2017, John Wiley and Sons). (C) Alteration in the fabricated 3D structure by applying a magnetic field; the originally printed shape was returned
when the magnetic field was removed (reproduced with permission from Ko et al. [113] ; copyright 2020, Elsevier). (D) Images showing the injected bioink
through a syringe to create self-supporting structure. (E) The images of magnetic ferrofluids, extrusion filament, and 3D-fabricated structure with magnetic-
responsive behavior. (F) Micro-CT images after implantation on 4 weeks and 8 weeks. (Figure D, E, and F reproduced with permission from Guo et al. [114] ;
copyright 2021, John Wiley and Sons). (G) Working principle showing drug-release through UV/green light stimulations. (H) Micropatterned patch by
3D bioprinting process. (I) Hematoxylin and eosin staining of skin tissue collected after 28 days to show the wound healing process. (Figures G, H, and I
reproduced with permission from Siebert et al. [116] ; copyright 2021, John Wiley and Sons).
4.2. Drug delivery for therapy of disease such as pH and biomolecule concentration. Therefore,

Conventional delivery systems require frequent and high- 3D-bioprinted constructs with stimuli-responsive
dose administration for success [118] . However, the adverse biomaterials are under development as smart drug
effects could badly influence the body and decrease the drug delivery systems. Wang et al. [119] proposed a hybrid bioink
efficacy. In line with precision medicine, an optimal drug with shape memory for drug delivery. Sodium alginate
delivery system should release pre-planned drugs under and Pluronic F127 diacrylate macromers (F127DA) were
harsh in vivo environmental conditions. Stimuli-responsive mixed to formulate shape-memory hydrogels (SMHs).
biomaterials have the potential to change their form in 3D printing was utilized as an effective tool to control the
response to external stimuli and changes in variables, internal structure of the shape memory hydrogels. This

Volume 9 Issue 1 (2023) 243 https://doi.org/10.18063/ijb.v9i1.638