Exosome-integrated bioinks for 3D bioprinting in regenerative medicine: Design strategies and applications
Exosome-containing “hybrid bioinks” integrate the mechanical properties of 3D bioinks with the bioactive contents of extracellular vesicles, enabling the fabrication of bioactive tissue constructs amenable to 3D printing. Here, we summarize how 3D bioprinting hybrid bioinks can develop tissue constructs with regeneration capacity, immunomodulatory function, angiogenic ability, and cell differentiation guidance. Despite recent advances in integrating exosomes into bioinks, the rational design of these systems remains underdeveloped. This limitation arises not only from the intrinsic complexity of vesicle–matrix interactions, but also from the lack of standardized design principles and unified performance evaluation frameworks. This challenge is further compounded by source-dependent heterogeneity in exosomal composition and function. In addition, current systems offer limited control over loading efficiency, spatial distribution, and release kinetics, and there is still no consensus on how to assess post-fabrication vesicle stability, bioactivity retention, or therapeutic performance. Together, these limitations hinder reproducibility, cross-study comparability, and the establishment of predictive design rules for clinically translatable exosome-integrated bioinks. Therefore, this review critically discusses recent trends in the design of exosome-laden bioconstructs, including their major advantages and drawbacks. From a design perspective, key considerations include bioactive matrix engineering, exosome loading, triggered release, and construct integrity during biofabrication. Design parameters affecting the overall performance of the construct are discussed in light of the challenges and standardization issues of developing clinically relevant exosome-loaded bioengineered constructs. Moreover, recent progress in exosome isolation and characterization and state-of-the-art enabling technologies are discussed. Therapeutic applications reviewed here include wound healing, musculoskeletal tissue engineering, neural repair, and cardiac regeneration, highlighting the diverse therapeutic potential of exosomes. In the last section, we outline programmable bioink integration, stimuli-responsive materials, and computational design approaches toward the future generation of biofabrication technologies for regenerative medicine and precision therapeutics.
