Scientists Develop 3D-Printable Tissue Glue for Quick Sealing in Surgical Situations

A 3D-printable tissue glue with exceptional tissue adhesion, quick sealing in a variety of surgical situations, and a special blood-repelling property has been created by MIT researchers. The technique has enormous potential to transform applications for biomedical devices and wound care. 

Nature Communications has published the research. Tissue adhesives offer advantages over more conventional wound closure techniques like staples and sutures, including faster application times, less scarring, and less tissue damage. Even while conventional adhesives work well, patients’ discomfort and the time-consuming, skill-dependent application process have led to a search for more creative solutions.  

For example, their efficacy may be lower when sealing highly mobile or irregularly shaped tissues. Furthermore, traditional adhesive application can be labor-intensive, resulting in longer surgical times. These techniques may also result in tissue damage, and the materials used may not always blend in perfectly with the body. Tissue adhesive innovations seek to address these shortcomings by offering more adaptable, effective, and patient-friendly options. The creation of 3D printable tissue adhesives, as demonstrated by the MIT study, opens new possibilities for tissue repair and wound closure.  

“The manufacturing flexibility that 3D printing offers has also captivated me as a mechanical engineer. We were inspired to investigate novel material solutions by the potential applications of 3D printable tissue adhesive, including personalized patches and soft bio-integrated devices.” 
“Our research focused on developing a 3D printable tissue adhesive capable of creating custom-sealing patches and devices,” Wu stated. A tissue adhesive ink made of poly (acrylic acid) grafted to polyurethane was created by the researchers. With certain chemical functional groups that are important for creating a strong bond with biological tissues, this composition’s uniqueness is essential for delivering strong adherence to tissues.  

The scientists added a blood-repelling hydrophobic matrix to the adhesive structure to improve its functioning. In difficult situations like those present in bleeding tissues, the matrix serves as a barrier that keeps the adhesive from coming into direct touch with body fluids and preserves its integrity. The precise start of the complex procedure involves 3D printing the tissue adhesive ink onto a glass slide covered in hydrophobic material to create a pattern with circular gaps for electrodes. This layer is essential to maintaining the adhesive’s performance, particularly when biological fluids are present.  

After that, an insulator layer made of polyurethane is printed on top of the adhesive layer. The adhesive’s effectiveness and stability during application are improved by this insulator layer. After that, the researcher’s 3D printed electrodes and circuits onto the structure using silver conductive ink. This stage demonstrates the adhesive’s versatility by permitting the possible integration of electronic components, should they be needed for certain applications.  

Using a tiny bit of silver ink, the researchers also integrated light-emitting LEDs into the circuit. This addition exemplifies the adhesive’s versatility and raises the possibility of its use in bio-integrated devices.  
 
After adhering the created bioelectronic patch to an ex vivo pig heart, a power source is used to pass current through the tissue, verifying the LEDs’ illumination and emphasizing the adhesive’s bioelectronic properties.  

The researchers carefully and methodically fitted the manufactured patches to various tissue abnormalities and then put them through a series of tests. These include characterization of adhesion, evaluations of rheology and mechanics, and biocompatibility investigations carried out using a rat battery in vivo test.  
When compared to currently available commercial materials, the tissue adhesive that can be printed in 3D showed great superiority in tissue adhesion performance. This accomplishment is highlighted by its quick tissue-sealing abilities in a range of surgical situations.  

An unexpected discovery made during the investigation could potentially add a blood-repellent solution to the adhesive. “Adhesion even to severely bleeding tissues was made possible by the ability to introduce a blood-repellent solution into the porous structure of our printed adhesive. Hemostasis is difficult to achieve in bloody situations because most tissue adhesive materials frequently fail,” Wu said. By forming a barrier that protects it from human fluids—a vital component for preserving the adhesive’s integrity, particularly in difficult bleeding situations—the use of a protective hydrophobic matrix improved the adhesive’s functioning even more.  

Their 3D printable tissue adhesive is at the forefront of biomedical materials because to its revolutionary blood-repellent infusion. It solves major problems that current adhesives have in blood-flowing settings, leading to a wide range of applications, from wound closure to possible bio-integrated devices.  

The bio adhesive, three-dimensionally printed tissue patches demonstrated exceptional durability and strength in various tissues. Mechanical testing showed they were resistant to tensile loads, burst pressures, and shear stresses, suggesting they might be used in various physiological settings. Their safety was validated by biocompatibility experiments, which showed little cytotoxicity. Additionally, in vivo models, such as those for trachea, colon, liver, and femoral artery repairs, demonstrated successful adhesion and integration into the surrounding tissue.  

The robustness and efficacy of these patches were established by quantitative insights into tissue regeneration obtained from micro-CT imaging following surgery. 

Journal Reference  

Sarah J. Wu et al, A 3D printable tissue adhesive, Nature Communications (2024). DOI: 10.1038/s41467-024-45147-9