Cancer is a disease that involves abnormal cell growth with the potential to spread to other parts of the body. Cancerous cells grow and divide without regulation, creating aggregates of cells called tumors. Although scientific knowledge surrounding cancer continues to grow, there is still much to learn about tumor activity. Cancer is the second leading cause of death. Approximately 1 in 6 deaths around the world is due to some form of cancer. In 2018, cancer was responsible for an estimated 9.6 million deaths.
Bioprinting has become increasingly useful in cancer research. Cancer cells can be biopsied from a patient, purified, and mixed with a bioprinting material, then bioprinted into 3D structures to test new drugs and study tumor activity.
Using bioprinting for tumor model generation offers the ability to form highly controllable cancer tissue models. The tumor microenvironment (TME) has long been established to play a critical role in cancer development and resistance to anti-cancer drugs. The TME contains a host of well-organized biochemical factors that help the cancer cells continue to grow rapidly and provides protection from the immune system. The distribution of biochemical factors in bioprinted constructs can be controlled in a way that creates a structure that mimics the native TME. The ability to mimic native tumor tissue shows potential to significantly accelerate cancer research.
Another huge advancement of cancer research made possible by bioprinting is the integration of perfusable vascular networks. The ability to generate blood vessels inside the tumor is a key characteristic of cancer. Tumor vascular networks allow for better transport of nutrients, waste, and biochemical factors, helping the tumor to grow and spread even faster. These hallmark features of cancer are what cancer cells depend on to adequately supply oxygen and nutrients and remove waste products. Historically, creating a tumor complete with vasculature has been very difficult as blood vessel networks are complex and delicate. However, with the advancement of bioprinting, researchers can now develop a vascular network embedded in the printed tumor to more closely mimic its natural structure. The incorporation of perfusable vascular structures in 3D architecture is highly useful for studying the invasion of cancer cells through vessels. Tumor models with vasculature increase the similarities between biological tumors and bioprinted copies, increasing the validity of results obtained from 3D cancer studies. It allows researchers to study how the tumor operates with a level of detail not possible before. Research into the development of perfusable vascular structures in cancerous tumors through bioprinting will provide the scientific community with an understanding of how heavily tumors rely on their vascular networks. When bioprinting, changing network parameters is an excellent way to determine which factors of vascular growth and structure have the greatest effect on tumor viability. With this knowledge, anti-cancer pharmaceuticals and chemotherapy treatments can be better developed. However, the inclusion of vascular networks in bioprinted tumor models is no easy feat; each component must be created individually and then pieced together. Vascular structures are highly delicate and contain significant detail, not to mention a variety of cells, each with a specialized function. Nevertheless, bioprinting makes it possible.
High-throughput Model Generation
Another example of bioprinting in cancer research is the high-throughput generation of cancer models. It often costs the healthcare system hundreds of thousands of dollars to treat each patient, especially for late-stage cancers. Research into cancer initiation and early diagnosis strategies can benefit both treatment cost and treatment outcome.
Bioprinting is one tool that has the potential to facilitate large-scale, high-throughput generation of cancer models, allowing faster production of cancer models and for more research to be widely conducted. High-throughput capabilities of bioprinting can facilitate easy production of many identical models with specific characteristics depending on the goal of the research project. Bioprinting can also create microtumor models, tumor-like structures that behave like cancer, but are smaller and can be bioprinted faster. Microtumor models provide data about the general behavior of a cancer without needing to spend extra time developing large models. The high-throughput nature of bioprinting allows data to be generated at a rate not possible before, helping to expedite cancer research and make treatments available faster.
Patient-Specific Cancer Models
Fabrication of patient-specific cancer models can expedite decisions on which treatment pathways to choose depending on how a patient’s specific cancer reacts to various treatments. Instead of subjecting a cancer patient to multiple therapeutics with no idea of their efficacy, cancer models can be bioprinted using cells from the patient’s own cancer. These models can be treated to determine how a patient’s cancer will react to different treatments. Individualized patient care has a large role to play in the development of western medicine, and high throughput bioprinting is one means through which this is becoming possible.
Bioprinting can be used by researchers in a multitude of ways to increase cancer research efficiencies and improve patient outcomes. These strategies still have a long way to go before they can be used in the clinic, but many believe that bioprinting is the future of medicine. We’re doing our part to support researchers in this field by making GelMA accessible to researchers everywhere.