Objective
The first objective of the LIGHTGRAFT project is to create a reliable and scalable way to produce therapeutic cells for 3D bioprinting. This involves setting up an automated, high-capacity system for creating key cell types from human stem cells: islet cells (for insulin production), blood vessel cells, and supportive cells. Using advanced robotic equipment, the team will monitor and optimize cell growth conditions to ensure high-quality production. We will also use design of experiments methods to fine-tune machine settings at every step to increase efficiency.
The second objective of the project is to develop complex, mature islet tissues with built-in blood vessels that can be used for transplantation. To achieve this, the team will embed these cells in a special 3D-printable hydrogel designed to support both cell function and blood vessel formation. This tissue will be printed with channels of different sizes that mimic blood vessels, allowing nutrients to flow and reach all cells effectively. Advanced techniques like volumetric bioprinting and multiphoton printing will help create these structures quickly and safely. By combining these printed channels with natural cell growth, the result will be a connected network of blood vessels across multiple scales, supporting the islet cells much like a natural pancreas.
The third objective is to test how well these bioprinted tissues work, both in lab settings and in living organisms. In the lab, the printed tissues will be grown in a system that mimics blood flow, helping cells mature and allowing scientists to monitor insulin production under different conditions. The most promising tissue designs will then be implanted in diabetic mice to test their ability to control blood glucose levels. Special reinforcement techniques will ensure the tissue stays in place after implantation. The team will closely study how quickly these bioprinted tissues connect to the bloodstream and how well they help restore normal blood glucose levels in these models.
Overall, this project aims to develop functional, implantable pancreatic tissue for potential diabetes treatments, focusing on creating a supportive environment for long-term cell survival and insulin production.
Background Rationale
A big challenge with current stem cell-derived islet (SC-islet) transplants for diabetes treatment is that the transplanted cells take a long time to connect to the patient’s blood vessels and become fully functional—often taking weeks or even months. To improve this, the LIGHTGRAFT project is developing new methods to speed up the integration of these SC-islets and make them last longer in the body. LIGHTGRAFT’s approach uses two advanced types of 3D bioprinting—volumetric bioprinting (which works quickly and without harming the cells) and multiphoton ablation (which creates tiny, precise structures). Together, these methods allow the team to create a protective capsule around SC-islets with materials that help the cells mature and function. The bioprinted structure includes a network of small channels that act like blood vessels, allowing the SC-islets to connect quickly to the body’s blood supply and start working faster. This multi-layered setup aims to make the transplants more durable and efficient. The project also focuses on making this process automatable and scalable, meaning it could be produced on a large scale to meet medical demand. LIGHTGRAFT leverages innovations like volumetric bioprinting, which prints complex cell structures without damaging them, at a speed faster than traditional extrusion-based 3D printing methods. Early tests show that these bioprinted SC-islets have better glucose sensitivity (a key to effective blood glucose regulation) and show signs of maturing more fully when printed in a supportive, 3D gel structure. LIGHTGRAFT builds on recent bioprinting advances and partnerships, like the collaboration between NovoNordisk and Aspect Biosystems, highlighting the growing importance of bioprinting in diabetes research. By creating reliable, quick-to-integrate, and durable SC-islet transplants, LIGHTGRAFT hopes to expand tools and methods in the field of pancreatic tissue engineering for future diabetes treatments.
Description of Project
LIGHTGRAFT aims to advance towards a cure for type 1 diabetes (T1D) by developing transplantable pancreatic tissue that can make insulin, using advanced 3D printing technology. This involves generating insulin-producing cells from human stem cells, which could be used as a treatment to replace damaged islet cells in the pancreas. However, there are current limitations: these lab-made islet cells often aren’t mature enough, don’t connect well to blood vessels, and lack supportive tissue needed for cell development. LIGHTGRAFT plans to overcome these challenges by bringing together experts in areas like human islet biology, stem cells, materials science, and bioprinting. The team has two main hypothesis:
- First, that by exposing the developing islet cells to signals from surrounding tissues, we can guide their growth and maturity.
- Second, that using a new type of 3D bioprinting to create connected blood vessels will help the cells connect to the body more quickly and allow for better blood glucose control.
Starting from these hypoethsis, the project has three main goals:
1) To create a reliable way to produce these therapeutic cells on a large scale. Automated lab systems will increase production speed for these stem cell-derived islets, as well as the blood vessel cells they need, while computer vision will help check quality.
2) To create fully developed, blood vessel-connected islet tissue for transplantation by using different types of 3D printing. Combining techniques, we aim to build a network of tiny and large blood vessels, producing functional tissue that is rich in islet cells.
3) To test how well these printed tissues work, both in the lab and in diabetic mice, to see if they connect quickly to the bloodstream and help control blood glucose.
Overall, LIGHTGRAFT aims to open new possibilities for diabetes treatment and research.
Anticipated Outcome
1. Automated production of insulin-producing cells and supportive blood vessel cells starting from stem cells:
The project’s first major outcome is the establishment of a highly efficient, automated system that can produce a) mature islets rich in insulin producing cells, and b) the supportive blood vessel cells they need. This system, based on human stem cells, will ensure a consistent supply of high-quality cells for future treatments. Importantly, it includes an automated quality control process to monitor each cell’s development and functionality, ensuring only the best cells are used for transplantation. With this automation, producing these vital cells becomes more scalable, and more reliable.
2. Advanced 3D bioprinted tissues with built-In blood vessels:
LIGHTGRAFT will result in 3D printed tissue structures that include both large and tiny, blood vessel-like channels to deliver nutrients and oxygen. Using an advanced bioprinting technique called volumetric printing, the team is creating detailed structures that mimic natural blood vessels, complete with interconnected channels across different ranges of sizes. This intricate network ensures the transplanted cells have access to the nutrients they need, which is crucial for their survival and rapid integration into the body. These structures will make the cell grafts more viable, functional, and long-lasting. In addition, these vessels will be laden with the cells that normally make up blood vessels. These cells produce molecules that push islets to perform more effectively their role in regulation blood glucose levels, and we expect it will enhance islet functionality after transplantation.
3. Long-term blood glucose control in animal models:
Finally, the team will test the bioprinted tissue in rodent models of diabetes to see if it can maintain normal blood sugar levels (euglycemia). Successful outcomes here would mean that the transplanted cells are not only surviving but also effectively controlling blood glucose over time. Achieving this result would be a significant step towards a treatment that could ultimately work in human patients, offering hope for a durable and functional diabetes cure.
Relevance to T1D
Using stem cells, specifically induced pluripotent stem cells (iPSCs), offers a way to create large amounts of pancreatic islets, which are critical for replacing damaged insulin-producing cells in type 1 diabetes (T1D). However, current methods have limitations. These lab-grown cells often aren’t fully mature, have mixed cell types that may interfere with function, and struggle to regulate blood glucose as effectively as natural islet cells. A key challenge is that, once transplanted, these cells need to quickly connect to the body’s blood supply to survive. Unfortunately, many fail to do this, take a long time to mature, and don’t reach full functionality until weeks or even months after implantation.
Research shows that certain cells in the pancreas, which are missing in current lab-grown islets, play a crucial role in helping islets mature. These supportive cells release signals that help the islets grow and function more like natural cells. To improve islet therapy, new methods are needed to make these lab-grown islets more mature and capable of surviving in the body, especially since effective treatment often requires a huge number of islets.
Recent advancements in 3D bioprinting hold promise for this. Bioprinting can create structures with built-in blood vessel networks, allowing cells to survive better by quickly connecting to the bloodstream after transplant. But existing bioprinting methods have limitations—they can damage delicate cell groups like islets and are too slow for producing large tissue volumes quickly. Additionally, current printing technologies struggle to make small, capillary-like blood vessels, which are essential for delivering nutrients to the cells and helping them regulate blood glucose effectively.
Another challenge is that a large quantity of cells—up to a billion cells per patient—is needed to treat diabetes. Scaling up production while keeping quality consistent is crucial to making this therapy widely available. The LIGHTGRAFT project aims to tackle these issues by using advanced, automated cell production and fast 3D bioprinting methods. This approach will enable the creation of stable, vascularized islet tissues in clinically relevant sizes, making the production process faster and ensuring the survival and functionality of the implanted cells for better diabetes treatment.