2024 & Beyond: Navigating Promising Frontiers in 3D Printed Medical Applications

In a time when technological advances and healthcare innovations intersect, the domain of 3D printed medical applications stands at the forefront of a transformative wave. While some of the most anticipated advances in 2024 promise the widespread use of custom-designed implants and prosthetics, advanced drug delivery systems, 3D printed models of patient-specific anatomies, bioresorbable devices, and wearable sensors, the field of 3D printing is rapidly evolving elsewhere, too.

The potential for unforeseen breakthroughs in the next decade is on the rise, promising to further expand the capabilities and applications of this technology in healthcare. As the industry grapples with challenges like an aging population, rising healthcare costs, and the need for personalized treatments, 3D printing stands out as an innovative force. Today, 3D printing extends beyond its initial novelty in healthcare practices, offering applications with the potential to broaden the scope of patient care. While this field’s expansion is remarkable, it’s not without challenges, such as regulatory hurdles, technological constraints, and ethical debates. However, the ongoing drive towards medical advances and enhancing patient outcomes strengthens the momentum in 3D printing.

Here, we delve into three innovations in 3D printed medical applications that could turn the tables for patients this decade, paving the way for a new chapter in medical science.

Tiny Titans

When it comes to minimally invasive surgery, 3D printed microbots are a strong innovation. Leading the charge in this revolutionary field is Brad Nelson of ETH Zurich, a robotics and intelligent systems veteran who recently elucidated his two-decade-long journey in a December 2023 paper in the journal Science. His microrobots have the potential to redefine the delivery of drugs within the human body, targeting illnesses with unprecedented precision. These microrobots, ranging in size from a micron to a few millimeters, can consist of synthetic, biological, or biohybrid materials. They would potentially “navigate to disease sites” – such as tumors or thrombi – to release drugs directly, reducing the systemic toxicity commonly associated with drug treatments. According to Nelson, “biomedical microrobots could overcome current challenges in targeted therapies.”

However, this pioneering work is not isolated. Other institutes worldwide are contributing to this niche. For example, Tufts University and Harvard’s Wyss Institute are looking into 3D printed microrobots that can autonomously move and stimulate neuron growth. University Of California, Berkeley, and Johns Hopkins University are all part of this global pursuit, each exploring unique elements of microrobotics in medicine. Seoul National University’s work on microrobots capable of navigating bodily fluids underlines the international collaborative effort towards revolutionizing this niche within minimally invasive surgeries.

Nelson points out that when translating microrobots from the lab to clinics, “It is important to focus on simplicity, at least for the first attempts.” The medical microrobots field has progressed in preclinical settings after researchers in South Korea demonstrated 3D printed minirobot’s capability to navigate autonomously through blood vessels and perform surgical tasks in pigs. Published in IEEE Robotics and Automation Letters, this development addressed challenges in treating occlusive vascular diseases, major causes of death.

However, despite these promising developments, technical and regulatory challenges line the path to widespread clinical use. As medical devices and drug delivery systems, microrobots face a unique regulatory landscape, requiring further studies to meet the U.S. Food and Drug Administration (FDA) standards and other bodies, mainly due to their novel drug-device combination nature.

Neural Nexus

Current research in neural 3D printed bioelectronic interfaces shows tangible progress, particularly in developing implants for the nervous system. Bioelectronic interfaces, designed as devices, link electronic systems with biological functions, thereby bridging the gap between technology and the human body. Teams from the University of Oxford and the University of Sheffield are pioneering this area. Oxford’s team has successfully 3D printed human stem cells to create tissue structures that integrate with mouse brain tissue. This suggests potential for repairing brain injuries and enhancing understanding of the human brain.

Instead, Sheffield’s team focuses on customizing implants for spinal cord stimulation in animal models, which indicates possible future applications in treating paralysis. These developments, primarily in preclinical stages, are steps towards more personalized and effective treatments for neurological conditions. However, the transition from laboratory to clinical application remains a work in progress, with ongoing efforts to refine these technologies for practical use in human patients.

Another specific example of this technological innovation is evident in the work carried out at Lancaster University, also in the U.K. Here, researchers, under the guidance of John Hardy, have developed an advanced 3D printing method to integrate flexible electronics into biocompatible materials. Published in Advanced Materials Technologies, this project represents a leap in manufacturing complex 3D electronics for surgical implants and medical device repairs. The team’s success in embedding an electrical circuit within a silicone-based flexible matrix and attaching it to a mouse brain slice to stimulate neuronal responses shows the potential of this technology. The researchers have even extended this to printing conducting structures directly into worms, demonstrating compatibility with living organisms.

Although further progress in laser technology and ink formulation is needed for clinical application, Lancaster University’s pioneering work opens new avenues for creating tailor-made bioelectronic devices for neural monitoring and personalized medical treatments. This indicates a promising future for bioelectronic interfaces in medicine.

It’s a Heart Thing

Heart diseases, among the leading causes of mortality worldwide, could see transformative treatments thanks to 3D printing technologies in bioengineering. Customized 3D printed heart valves are at the forefront of this revolution. A beacon of hope for over 30 million people suffering from valvular heart diseases, this innovation represents a significant stride in tackling some of the most pressing health challenges of our times. Although the FDA approval status for these valves is still pending, and their clinical application is in the developmental stages, their potential is immense.

With over 182,000 valve replacements performed annually in the United States alone, it’s clear why the market is moving towards minimally invasive solutions. By 2026, the number of heart valve replacements in the U.S. will exceed 240,000. Tailored to individual patient anatomy, 3D printed valves can improve surgical outcomes and reduce the need for future surgeries, especially in pediatric patients.

Current heart valves are typically permanent devices with critical limitations. In pediatric patients who grow at rapid rates, they quickly become too small, which increases the need for replacements. Although 3D printed heart valves exist and bioresorbable materials have been used for implants, the two have not been combined.

Researchers at the Georgia Institute of Technology spearhead patient-specific, bioresorbable heart valves designed to reduce complications and reinterventions. Unlike permanent devices, these 3D printed valves are designed to be absorbed and replaced by the body’s tissue over time. This technology is particularly beneficial for children, as the valves can adapt and grow with the patient, potentially reducing the need for multiple surgeries. The valves are crafted using a combination of polymeric and metallic materials, each selected to match the specific mechanical behavior of the patient’s tissue. The design process involves detailed consideration of the patient’s anatomy, age, condition, and the required delivery mechanism.

An iteration of the prototype (left). The valve can be seen closing (center) and opening (right) under physiological aortic flow conditions via a pulse duplicator. Image courtesy of Georgia Tech.

In addition to functional benefits, manufacturers can customize these valves at the surface level to enhance integration with surrounding tissues and promote cell growth. Researchers at Canada’s Sainte-Justine Hospital are exploring using hydrogels and patient-derived stem cells in these valves to create a fully personalized solution less prone to rejection. This “personalized medicine” approach could revolutionize the treatment of various cardiovascular diseases and conditions.

These 3D printed heart valves are still in the experimental phase, with ongoing animal studies and human trials expected to begin in about a decade. This breakthrough could significantly improve the quality of life and treatment outcomes for millions of heart disease patients worldwide. The ability to tailor these valves to individual patient anatomy and conditions enhances the success rate of surgeries. It opens up new possibilities for treating a wide range of cardiovascular diseases, including congenital heart defects and valve stenosis.

Researchers at Canada’s Sainte-Justine Hospital produce 3D printed heart valves. Image courtesy of Sainte-Justine Hospital.

Together, this progress in 3D printed medical applications illustrates the potential of 3D printing in medicine and the collaborative and dynamic nature of research that spans continents and institutes, heralding a new era in medical treatments and patient care.

Featured image courtesy of Stratasys.