Will 3D Printable Tissue Adhesives Replace Stitches and Clips?

Why We Need Tissue Adhesives

Adhesives are not new in healthcare, but previous efforts to create quick, effective, and biocompatible tissue adhesives have mostly resulted in bioadhesive hydrogels cast in molds. These offer only limited material and shape options, limiting their usability.

The authors of the study therefore focused on developing a special ink for direct 3D printing, which allows the production of patches and structures with adjustable internal structure and geometry as well as satisfactory adhesiveness. Compared to traditional stitches and clips, they offer greater versatility, easier application, and a lower risk of damaging surrounding tissues.

Material and Mechanical Properties

The printable ink is based on a polymer network composed of polyacrylic acid ester and N-hydroxysuccinimide, interspersed with hydrophilic polyurethane. This prepared viscoelastic ink is suitable for direct 3D printing, which after printing on the printing substrate does not require any further processing.

After application at the site of use, the material adapts to the surrounding physiological environment. The network structures and pores increase flexibility and facilitate material exchange. Thanks to its elastomeric mechanical properties, it also adapts to different wound geometries and surrounding tissues, and evenly distributes tension and other acting forces in movable areas.

Use in Intestinal or Vascular Perforations or Severe Internal Bleeding...

The advantage of 3D printable adhesive and patch is the ability to change its internal geometric parameters, such as fiber density or angle, thereby adjusting the properties of the printed product. Since individual tissues have a wide and diverse range of properties, customizing the internal structure of the adhesive or patch can ensure a better fit between them and the adhesive surface.

According to the authors of the study, patches made of 3D printed adhesive could be suitable, for example, for intestinal perforations, blood vessels, or the trachea. Current treatment options in many of these cases are limited – stitches can tear the cartilaginous tissues of the trachea due to their high tension, while flowing adhesives can penetrate the wound and block organs. Custom-designed flexible patches from a 3D printer can adapt to the tracheal surface or other organ and securely seal the damaged area within seconds.

3D printed patches could also be useful in treating severe internal bleeding. Most current adhesives and patches exhibit significantly worse adhesive properties in the presence of blood. However, when designing the structure of the used material, it is possible to enrich the source material with hydrophobic components and pores, which repel and divert the surrounding blood, allowing the adhesive direct contact with the tissue.

... and Perhaps Even for Attaching Bioelectronics Inside the Body?

Tests ex vivo, in vitro, and in vivo on rats have shown promising capabilities of the designed materials in wound healing, adhesion, biocompatibility, and blood resistance. According to the study's authors, they are also potentially promising for attaching bioelectronics or drug delivery systems inside the body.

To fully assess the efficacy and biocompatibility of 3D printed patches and all possible modifications, further and more extensive research will be needed. However, the current study shows that the proposed methods and tools are a suitable direction for further development of 3D printing in healthcare.

(jko)

Source: Wu S. J., Wu J., Kaser S. J. et al. A 3D printable tissue adhesive. Nat Commun 2024 Feb 9; 15 (1): 1215, doi: 10.1038/s41467-024-45147-9.