Microphysiological systems (MPS), often called “organs-on-chips,” are a significant advancement in biomedical research. These platforms recreate human biology outside the body in a controlled, miniature environment. MPS are being explored for their potential to transform how we study health and disease, offering a new approach to understanding biological processes and developing therapies more accurately than traditional methods.
Understanding Microphysiological Systems
Microphysiological systems are laboratory tools that integrate living human cells within micro-engineered environments. These systems typically consist of a clear, flexible polymer device containing hollow microfluidic channels. These channels are lined with specific human organ cells, such as those from the lung, liver, heart, or kidney, and sometimes include human blood vessel cells. A supportive scaffold or matrix within the chip provides a three-dimensional structure, mimicking the natural tissue environment.
The “micro-” aspect refers to the precise, small-scale engineering that replicates the microenvironment of human tissues. Microfluidic technology enables precise control of fluid flow, delivering nutrients and removing waste, similar to how blood circulates. This dynamic environment, including mechanical cues like stretch or perfusion, allows cultured cells to exhibit functions that emulate organ-level physiology. Unlike traditional two-dimensional cell cultures, MPS provide a more physiologically relevant setting by incorporating features such as 3D structure, fluid flow, and cell-to-cell interactions.
Why They Matter: Advantages and Applications
Microphysiological systems offer several advantages over conventional research methods. One benefit is their potential to reduce or replace animal testing. Animal models have ethical considerations and species differences that can limit the translation of research findings to humans. MPS, by using human-derived cells, provide a more relevant platform for studying human physiology and disease, aligning with ethical concerns and animal welfare regulations.
These systems can improve drug development by more accurately predicting drug efficacy and toxicity in humans. Traditional drug screening often relies on 2D cell cultures and animal models, which may not reliably predict human responses, leading to high failure rates in clinical trials. MPS can screen compounds faster and at lower costs, helping to identify promising drug candidates with a greater probability of success and improving patient safety. They allow researchers to assess drug-induced side effects and adverse reactions early in development.
MPS are also valuable for understanding complex human diseases. They can mimic disease progression in a controlled environment, modeling cancer, neurodegenerative diseases, or infectious diseases. For instance, MPS have been used to study Alzheimer’s disease by integrating human neurons, astrocytes, and microglia in a 3D model. MPS also hold promise for personalized medicine. By using a patient’s own cells, researchers can create a “patient-on-a-chip” to test different drug regimens and optimize treatments. This approach allows for customized therapies based on a patient’s unique genetic makeup and disease characteristics.
The Path Forward: Challenges and Future Potential
Despite their promise, microphysiological systems face several challenges for broader adoption. Manufacturing these complex systems can be difficult and costly, requiring standardization across different laboratories. Ensuring consistent results and validating these models against human clinical data are hurdles. Replicating the full complexity of a whole human body on a chip, including intricate organ interactions and immune responses, remains a challenge. Issues like cell sourcing, reproducibility, and balancing complexity with experimental control require ongoing research.
Looking ahead, the potential of MPS is significant. Researchers are developing “body-on-a-chip” or “multi-organ systems” where multiple organ chips are connected to simulate systemic interactions. This interconnectedness allows for studying how drugs affect different organs simultaneously and how organs communicate. Such advancements could revolutionize pharmaceutical research, toxicology, and even space biology. Ongoing research focuses on overcoming current limitations, with collaborations among academia, industry, and regulatory agencies aiming to establish standardized protocols and validation criteria. The goal is to make MPS a more effective tool for drug testing and development, ultimately reducing reliance on animal models and improving human health outcomes.