Biofabrication approaches and regulatory framework of metastatic tumor-on-a-chip models for precision oncology

Immunocompetent tumor-on-a-chip: A translational tool for drug screening and cancer therapy

Tumor is one of the major diseases endangering human health while establishing an efficient in vitro tumor microenvironment (TME) model, which is an effective way to reveal the nature of the tumor and develop therapeutic methods. In recent years, due to the continuous development of lab-on-a-chip technology and tumor biology, various tumor-on-a-chip models applied to oncology research have emerged. Among them, the Immunotherapy-on-a-chip (ITOC) platform stands out with its ability to reflect immunological behavior in the TME. It is a class of in vitro tumor-on-a-chip with immune activity, which has good performance and the ability to reproduce TME. It can highly simulate the complex pathophysiological characteristics of tumors and be used to study various features related to tumor biological behavior. Currently, many advantageous functions and application values of ITOC platforms have been discovered and applied to tumor drug screening and development, tumor immunotherapy, and personalized therapy. In conclusion, the tumor-on-a-chip platform is a highly promising model for medical oncology research. In this review, the background of the ITOC platform, key factors for constructing an ideal ITOC platform, and the specific applications of ITOC platforms in tumor research and treatment are introduced.

Triplicate Dynamic Cell Culture Platform for Enhanced Reproducibility in Anti-Cancer Drug Testing

The development of stable and standardized in vitro cytotoxicity testing models is essential for drug discovery and personalized medicine. Microfluidic technologies, recognized for their small size, reduced reagent consumption, and control over experimental variables, have gained considerable attention. However, challenges associated with external pumps, particularly inconsistencies between individual pumping systems, have limited the real-world application of cancer-on-a-chip technology. This study introduces a novel triplicate cell culture system (Tri-CS) that simultaneously supports dynamic cultures in three independent units using a single peristaltic pump, ensuring consistent flow conditions. Our findings demonstrate that the Tri-CS significantly reduces variability compared to individual pump systems, enhancing the reliability of anticancer drug cytotoxicity testing. Furthermore, we evaluated gemcitabine cytotoxicity, which shows enhanced drug efficacy in dynamic conditions. Fluorescein diffusion tests revealed greater diffusion efficiency in dynamic cultures, which contributed to the higher observed drug efficacy. The potential for broader application of the Tri-CS, including its compatibility with commercially available transwells and the opportunity for use in more complex cancer-on-chip models, positions this system as a valuable tool for advancing microphysiological systems in preclinical research.

A systematic review on the culture methods and applications of 3D tumoroids for cancer research and personalized medicine

Cancer is a highly heterogeneous disease, and thus treatment responses vary greatly between patients. To improve therapy efficacy and outcome for cancer patients, more representative and patient-specific preclinical models are needed. Organoids and tumoroids are 3D cell culture models that typically retain the genetic and epigenetic characteristics, as well as the morphology, of their tissue of origin. Thus, they can be used to understand the underlying mechanisms of cancer initiation, progression, and metastasis in a more physiological setting. Additionally, co-culture methods of tumoroids and cancer-associated cells can help to understand the interplay between a tumor and its tumor microenvironment. In recent years, tumoroids have already helped to refine treatments and to identify new targets for cancer therapy. Advanced culturing systems such as chip-based fluidic devices and bioprinting methods in combination with tumoroids have been used for high-throughput applications for personalized medicine. Even though organoid and tumoroid models are complex in vitro systems, validation of results in vivo is still the common practice. Here, we describe how both animal- and human-derived tumoroids have helped to identify novel vulnerabilities for cancer treatment in recent years, and how they are currently used for precision medicine.

Bioprinting of Cells, Organoids and Organs-on-a-Chip Together with Hydrogels Improves Structural and Mechanical Cues

The 3D bioprinting technique has made enormous progress in tissue engineering, regenerative medicine and research into diseases such as cancer. Apart from individual cells, a collection of cells, such as organoids, can be printed in combination with various hydrogels. It can be hypothesized that 3D bioprinting will even become a promising tool for mechanobiological analyses of cells, organoids and their matrix environments in highly defined and precisely structured 3D environments, in which the mechanical properties of the cell environment can be individually adjusted. Mechanical obstacles or bead markers can be integrated into bioprinted samples to analyze mechanical deformations and forces within these bioprinted constructs, such as 3D organoids, and to perform biophysical analysis in complex 3D systems, which are still not standard techniques. The review highlights the advances of 3D and 4D printing technologies in integrating mechanobiological cues so that the next step will be a detailed analysis of key future biophysical research directions in organoid generation for the development of disease model systems, tissue regeneration and drug testing from a biophysical perspective. Finally, the review highlights the combination of bioprinted hydrogels, such as pure natural or synthetic hydrogels and mixtures, with organoids, organoid-cell co-cultures, organ-on-a-chip systems and organoid-organ-on-a chip combinations and introduces the use of assembloids to determine the mutual interactions of different cell types and cell-matrix interferences in specific biological and mechanical environments.

Beyond stiffness: deciphering the role of viscoelasticity in cancer evolution and treatment response

There is increasing evidence that cancer progression is linked to tissue viscoelasticity, which challenges the commonly accepted notion that stiffness is the main mechanical hallmark of cancer. However, this new insight has not reached widespread clinical use, as most clinical trials focus on the application of tissue elasticity and stiffness in diagnostic, therapeutic, and surgical planning. Therefore, there is a need to advance the fundamental understanding of the effect of viscoelasticity on cancer progression, to develop novel mechanical biomarkers of clinical significance. Tissue viscoelasticity is largely determined by the extracellular matrix (ECM), which can be simulatedin vitrousing hydrogel-based platforms. Since the mechanical properties of hydrogels can be easily adjusted by changing parameters such as molecular weight and crosslinking type, they provide a platform to systematically study the relationship between ECM viscoelasticity and cancer progression. This review begins with an overview of cancer viscoelasticity, describing how tumor cells interact with biophysical signals in their environment, how they contribute to tumor viscoelasticity, and how this translates into cancer progression. Next, an overview of clinical trials focused on measuring biomechanical properties of tumors is presented, highlighting the biomechanical properties utilized for cancer diagnosis and monitoring. Finally, this review examines the use of biofabricated tumor models for studying the impact of ECM viscoelasticity on cancer behavior and progression and it explores potential avenues for future research on the production of more sophisticated and biomimetic tumor models, as well as their mechanical evaluation.

The Edifice of Vasculature-On-Chips: A Focused Review on the Key Elements and Assembly of Angiogenesis Models

The conception of vascularized organ-on-a-chip models provides researchers with the ability to supply controlled biological and physical cues that simulate the in vivo dynamic microphysiological environment of native blood vessels. The intention of this niche research area is to improve our understanding of the role of the vasculature in health or disease progression in vitro by allowing researchers to monitor angiogenic responses and cell-cell or cell-matrix interactions in real time. This review offers a comprehensive overview of the essential elements, including cells, biomaterials, microenvironmental factors, microfluidic chip design, and standard validation procedures that currently govern angiogenesis-on-a-chip assemblies. In addition, we emphasize the importance of incorporating a microvasculature component into organ-on-chip devices in critical biomedical research areas, such as tissue engineering, drug discovery, and disease modeling. Ultimately, advances in this area of research could provide innovative solutions and a personalized approach to ongoing medical challenges.