Recently, decellularized extracellular matrix-based bio-ink (dECM bio-ink) derived from animal organs is attracting attention because of its excellent biocompatibility. However, its poor 3D printability and weak mechanical properties remain a challenge. Here, we developed a new dECM bio-ink with enhanced 3D printability and mechanical properties. dECM micro-particles of about 13.4 μ m in size were prepared by decellularizing a porcine liver followed by freeze-milling. The new bio-ink, named as dECM powder-based bio-ink (dECM pBio-ink), was prepared by loading the dECM micro-particles into a gelatin mixture. The usefulness of the dECM pBio-ink was evaluated by assessing its mechanical properties, printability, and cytocompatibility. The results showed that its mechanical properties and 3D printability were greatly improved. Its elastic modulus increased by up to 9.17 times that of the conventional dECM bio-ink. Micro-patterns with living cells were successfully achieved with 93% cell viability. Above all, the new bio-ink showed superior performance in stacking of layers for 3D printing, whereas the conventional bio-ink could not maintain its shape. Finally, we demonstrated that the dECM pBio-ink possessed comparable cytocompatibility with the conventional dECM bio-ink through in vitro tests with endothelial cells and primary mouse hepatocytes.

Demineralized dentin matrix (DDM)-based materials have been actively developed and are well-known for their excellent performance in dental tissue regeneration. However, DDM-based bio-ink suitable for fabrication of engineered dental tissues that are patient-specific in terms of shape and size, has not yet been developed. In this study, we developed a DDM particle-based bio-ink (DDMp bio-ink) with enhanced three-dimensional (3D) printability. The bio-ink was prepared by mixing DDM particles and a fibrinogen–gelatin mixture homogeneously. The effects of DDMp concentration on the 3D printability of the bio-ink and dental cell compatibility were investigated. As the DDMp concentration increased, the viscosity and shear thinning behavior of the bio-ink improved gradually, which led to the improvement of the ink’s 3D printability. The higher the DDMp content, the better were the printing resolution and stacking ability of the 3D printing. The printable minimum line width of 10% w/v DDMp bio-ink was approximately 252 μm, whereas the fibrinogen–gelatin mixture was approximately 363 μm. The ink’s cytocompatibility test with dental pulp stem cells (DPSCs) exhibited greater than 95% cell viability. In addition, as the DDMp concentration increased, odontogenic differentiation of DPSCs was significantly enhanced. Finally, we demonstrated that cellular constructs with 3D patient-specific shapes and clinically relevant sizes could be fabricated through co-printing of polycaprolactone and DPSC-laden DDMp bio-ink.

3D printed biomaterials have been extensively investigated and developed in the field of bone regeneration related to clinical issues. However, specific applications of 3D printed biomaterials in different dental areas have seldom been reported. In this study, we aimed to and successfully fabricated 3D poly (lactic-co-glycolic acid)/β-tricalcium phosphate (3D-PLGA/TCP) and 3D β-tricalcium phosphate (3D-TCP) scaffolds using two relatively distinct 3D printing (3DP) technologies. Conjunctively, we compared and investigated mechanical and biological responses on human dental pulp stem cells (hDPSCs). Physicochemical properties of the scaffolds, including pore structure, chemical elements, and compression modulus, were characterized. hDPSCs were cultured on scaffolds for subsequent investigations of biocompatibility and osteoconductivity. Our findings indicate that 3D printed PLGA/TCP and β-tricalcium phosphate (β-TCP) scaffolds possessed a highly interconnected and porous structure. 3D-TCP scaffolds exhibited better compressive strength than 3D-PLGA/TCP scaffolds, while the 3D-PLGA/TCP scaffolds revealed a flexible mechanical performance. The introduction of 3D structure and β-TCP components increased the adhesion and proliferation of hDPSCs and promoted osteogenic differentiation. In conclusion, 3D-PLGA/TCP and 3D-TCP scaffolds, with the incorporation of hDPSCs as a personalized restoration approach, has a prospective potential to repair minor and critical bone defects in oral and maxillofacial surgery, respectively.

Vascularization remains a critical challenge in tissue engineering, limiting graft survival, integration, and clinical translation. Although bioprinting enables spatial control over vascular architectures, many existing approaches prioritize geometric precision over biological performance. Bioprinted vasculature can be understood as a dynamic and time-dependent system that requires tissue-specific maturation. Within this framework, hydrogel systems act as active microenvironments rather than passive scaffolds. Hydrogel platforms vary from natural matrices and synthetic polymers to bioinspired or stimuli-responsive systems, each offering tunable control over stiffness, degradation, and biochemical signaling needed for vascular maturation. The design requirements of large and small vessels differ in terms of mechanical demands, remodeling capacity, and host integration. A key limitation in current models is the absence of time-resolved evaluation, as critical processes such as lumen formation, pericyte recruitment, and flow-induced remodeling occur progressively and are not captured by static endpoints. Advancements in bioprinting technologies are evaluated based on their capacity to support hydrogel-mediated vascularization across varying length scales and structural complexities. A framework for functional assessment is proposed, and translational challenges related to immunogenicity, scalability, and regulatory requirements are discussed. Such integration of hydrogel-driven biological cues and bioprinting fidelity is critical to advancing vascularized constructs toward clinical translation.

Autologous fat is widely used in soft tissue reconstruction; however, significant volume reduction owing to necrosis and degradation of the transplanted adipose tissue (AT) remains a major challenge. To address this issue, a novel live AT micro‐fragment–based bio‐ink (ATmf bio‐ink) compatible with precision 3D printing, is developed. Live AT micro‐fragments of ≈280 µm in size are prepared using a custom tissue micronizer and they are incorporated into a fibrinogen/gelatin mixture to create the ATmf bio‐ink. AT micro‐fragments exhibit high viability and preserve the heterogeneous cell population and extracellular matrix of the native AT. The developed bio‐ink enables precise micropatterning and provides an excellent adipo‐inductive microenvironment. AT grafts produced by co‐printing the bio‐ink with polycaprolactone demonstrate a 500% improvement in volume retention and a 300% increase in blood vessel infiltration in vivo compared with conventional microfat grafts. In vivo engraftment of AT grafts is further enhanced by using a stem cell–laden ATmf bio‐ink. Last, it is successfully demonstrated that the bio‐ink is enabled for the creation of clinically relevant and patient‐specific AT grafts for patients undergoing partial mastectomy. This novel ATmf bio‐ink for volumetric soft tissue reconstruction offers a pioneering solution for addressing the limitations of existing clinical techniques.