A challenge for bioprinting tissue constructs is enabling the viability and functionality of encapsulated cells. Rationally designed bioink that can create appropriate biophysical cues shows great promise for overcoming such challenges. Here, a nanoparticle-stabilized emulsion bioink for direct fabrication of porous tissue constructs by digital light processing based 3D bioprinting technology is introduced. The emulsion bioink is integrated by the mixture of aqueous dextran microdroplets and gelatin methacryloyl solution and is further rendered stable by 𝜷-lactoglobulin nanoparticles. After bioprinting, the printed tissue constructs create the macroporous structure via removal of dextran, thereby providing favorable biophysical cues to promote the viability, proliferation, and spreading of the encapsulated cells. Moreover, a trachea-shaped construct containing chondrocytes is bioprinted and implanted in vivo. The results demonstrate that the generated macroporous construct is of benefit to cartilage tissue rebuilding. This work offers an advanced bioink for the fabrication of living tissue constructs by activating the cell behaviors and functions in situ and can lead to the development of 3D bioprinting.

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In article number 2102810 by Rui Liu and co-workers, a nanoparticle-stabilized emulsion bioink via integration of two immiscible aqueous phases is developed to directly bioprint macroporous hydrogel constructs. The bioprinted macroporous hydrogel constructs do excellent service to the proliferation, spreading, and maturation of encapsulated cells in vitro and in vivo.

Subperiosteal implants represent an alternative implant approach for cases with severe bone atrophy. Although some successful clinical cases have been reported, the biomechanical stability of subperiosteal implants remains unclear, and more data are needed to confirm the feasibility of this approach. Therefore, this study investigated the biomechanical characteristics of subperiosteal implants based on histological observation, clinical cases, and finite element analysis. Finite element analysis indicated that subperiosteal implants with a lattice-like structure could better disperse the stress to the underlying bone surface. A novel customized subperiosteal implant was then digitally designed and fabricated using an additive manufacturing technology. Six beagle dogs received such customized subperiosteal implants. Histological and microcomputed tomography examination showed new bone growth into and around the implant. Patient-specific subperiosteal implants were placed into the edentulous mandibular bone, with immediate loading. The implant was functional, without pain or infection, over a 12 month observation period. Images taken 12 months post-operatively showed new bone formation and osseointegration of the device. This indicated that 3D-printed lattice-like subperiosteal implants have sufficient stability for the rehabilitation of severely atrophic ridges.