4D printing of core–shell hydrogel capsules for smart controlled drug release

4D bioprinting of programmed dynamic tissues

“…Making use of this feature, some schemes have been proposed for developing shape morphing hydrogels (SMHs) by introducing uneven swelling or shrinking into different parts of the hydrogels, leading to nonuniform internal stress and shape-morphing process for the hydrogels. While most SMHs respond to water, however, their shape morphing behavior can also be triggered by other stimuli, such as temperature [ 126 ], ions [ 43 , 127 ], pH [ 45 ], and charge interactions [ 128 , 129 ]. SMHs are appealing candidates for 4D bioprinting due to their unique advantages, such as excellent biocompatibility, good biodegradability, similarity to extracellular matrix (ECM), ability to support cell survival and growth, and crosslinking ability [ 20 , 33 , 130 ].…”

Advances in antimicrobial hydrogels for dental tissue engineering: regenerative strategies for endodontics and periodontics

“…185,187 Moreover, 4D-printed hydrogels have been receiving attention for disease-specific and condition-dependent drug delivery formulations involving the precise release of multiple bioactive agents and control over the release time and the targeted local release region in an intelligent manner. [186][187][188] Such kind of drug delivery platforms or stimuli-responsive biomaterials sensitive to intrinsic ( pH, enzyme, ROS, etc.) and extrinsic (temperature, light, ultrasound, mechanical force, electric or magnetic fields, etc.)…”

Development of digital light processing-based multi-material bioprinting for fabrication of heterogeneous tissue constructs

“…4,5 LBB employs laser energy to pattern cells and fabricate 3D tissue constructs, and can be categorized into two submodalities which are based on vat photopolymerization and cell transfer. 6,7 Multi-material bioprinting using these techniques has been studied, and bioprinted constructs exhibited functional gradients in terms of mechanical, 8,9 chemical, 10,11 or biological properties, [12][13][14] due to the presence of multiple materials. In recent years, several new strategies for multi-material 3D printing using different processes have been reported.…”