Irem Deniz Derman

Microvalve-based bioprinting (MBB) enables precise deposition of bioinks in the form of droplets through the controlled ejection of nanoliter-scale cylindrical ligaments. Despite its increasing use in tissue biofabrication, standardization criteria for assessing bioink printability remain limited. In this study, we present a quantitative printability toolbox for evaluating various bioinks, including fibrinogen, collagen type I, Matrigel, and alginate, in the context of MBB. We systematically analyzed how rheological properties and the contact angle influence ligament formation and droplet ejection. High-speed imaging captured ligament dynamics such as velocity and volume as well as droplet-substrate interactions. The role of Tween 20 (T20) surfactant was further investigated to reduce interfacial aggregation and improve droplet uniformity. Our results revealed viscosity and concentration thresholds specific to each bioink, enabling the construction of a comprehensive printability map correlating bioink properties with ligament stability and droplet printability. This framework provides a practical guide for bioink optimization in MBB towards reproducible fabrication of complex biological structures for biomedical applications.

This review examines the transformative role of artificial intelligence (AI) in 3D bioprinting, focusing on how advanced AI technologies enhance its precision, functionality, and scalability. AI, through branches, such as machine learning (ML), computer vision (CV), robotics, natural language processing (NLP), and expert systems (ES), provides critical improvements in real‐time process monitoring, error correction, and optimization of bioprinting parameters. The integration of AI enables automated quality control and predictive maintenance, improving bioprinting outcomes by increasing cell viability and structural fidelity, and reducing the amount of bioink wasted. Specifically, ML algorithms are employed to predict optimal bioprinting conditions and streamline the bioprinting workflow, while deep learning enhances the ability to process complex datasets for precision tissue biofabrication. Furthermore, AI‐powered robotics and CV systems ensure accurate bioink placement and facilitate the construction of complex tissues. Despite the remarkable progress, challenges remain, particularly in the areas of process monitoring, quality control, and the scalability of bioprinting systems. This review also aims to guide scientists, engineers, and healthcare providers in understanding the complexities and potential of AI‐enhanced bioprinting, fostering a deeper appreciation of its role in the future of regenerative medicine and personalized healthcare.

Three-dimensional (3D) bioprinting facilitates the automated patterning of biological entities (such as cells and tissue building blocks) with or without scaffolding biomaterials. The technique enables fabrication of highly organized structures that recapitulate the physiological and biological functions of native tissues. Droplet-based bioprinting (DBB) is unique among the existing bioprinting modalities in its ability to handle and manipulate bioprinting at the cellular level, as well as to develop complex 3D constructs in a high-throughput manner. As an evolving bioprinting modality, DBB has greatly advanced our understanding of cell interactions, tissue and organ formation, and human disease. This Primer gives an overview of the methodology of DBB, detailing its various modalities and its associated hardware and software, including the selection of bioinks and substrates, as well as their interactions and compatibility with different DBB sub-modalities. Finally, recent advances and several limitations of DBB are summarized and considerations are discussed for potential improvements to the technology in the future.

The epithelium is one of the important tissues in the body as it plays a crucial barrier role serving as a gateway into and out of the body. Most organs in the body contain an epithelial tissue component, where the tightly connected, organ-specific epithelial cells organize into cysts, invaginations, or tubules, thereby performing distinct to endocrine or exocrine secretory functions. Despite the significance of epithelium, engineering functional epithelium in vitro has remained a challenge due to it is special architecture, heterotypic composition of epithelial tissues, and most importantly, difficulty in attaining the apico-basal and planar polarity of epithelial cells. Bioprinting has brought a paradigm shift in fabricating such apico-basal polarized tissues. In this review, we provide an overview of epithelial tissues and provide insights on recapitulating their cellular arrangement and polarization to achieve epithelial function. We describe the different bioprinting techniques that have been successful in engineering polarized epithelium, which can serve as in vitro models for understanding homeostasis and studying diseased conditions. We also discuss the different attempts that have been investigated to study these 3D bioprinted engineered epithelium for preclinical use. Finally, we highlight the challenges and the opportunities that need to be addressed for translation of 3D bioprinted epithelial tissues towards paving way for personalized healthcare in the future.

This comprehensive review explores the multifaceted landscape of skin bioprinting, revolutionizing dermatological research. The applications of skin bioprinting utilizing techniques like extrusion-, droplet-, laser- and light-based methods, with specialized bioinks for skin biofabrication have been critically reviewed along with the intricate aspects of bioprinting hair follicles, sweat glands, and achieving skin pigmentation. Challenges remain with the need for vascularization, safety concerns, and the integration of automated processes for effective clinical translation. The review further investigates the incorporation of biosensor technologies, emphasizing their role in monitoring and enhancing the wound healing process. While highlighting the remarkable progress in the field, critical limitations and concerns are critically examined to provide a balanced perspective. This synthesis aims to guide scientists, engineers, and healthcare providers, fostering a deeper understanding of the current state, challenges, and future directions in skin bioprinting for transformative applications in tissue engineering and regenerative medicine.

In this study, we developed a three-dimensionally (3D) printed lung model that faithfully recapitulates the intricate lung environment. This 3D model incorporated alveolar and vascular components that allow for a comprehensive exploration of lung physiology and responses to infection in vitro . In particular, we investigated the intricate role of ventilation on formation of the alveolar epithelial layer and its response to viral infections. In this regard, we subjected our 3D printed, perfused lung model to a continuous respiratory cycle at the air-liquid interface (ALI) for up to 10 days followed by infection with two viruses: influenza virus (Pr8) and respiratory syncytial virus (RSV), at two different concentrations for 24 or 48 h. The results revealed that ventilation induced increased tight-junction formation with better epithelial barrier function over time, facilitated higher expression of alveolar epithelial specific genes, enabled higher level of infection with an increased progression of viral spread and replication over time, and modulated the production of pro-inflammatory cytokines and chemokines. Our findings represent a critical step forward in advancing our understanding of lung-specific viral responses and respiratory infections in response to ventilation, which sheds light on vital aspects of pulmonary physiology and pathobiology.