PU-Based 3D-Printed Natural Tissue Substitute Developed

Researchers from the Fraunhofer Institute for Applied Polymer Research IAP and the NMI Natural and Medical Sciences Institute have developed a biomimetic tissue substitute that combines tunable mechanical strength with biological functionality, opening new possibilities for medical implants.

The material was created under the PolyKARD project, funded by the Federal Ministry of Research, Technology and Space (BMFTR). The goal was to replicate the complex mechanical behavior of natural tissues particularly the pericardium, which is flexible at low strain but stiffens significantly under higher load.

Hybrid Structure Mimics Natural Tissue

The research team designed a multilayer material that integrates structural engineering with biomaterials. The base layer consists of a dense polyurethane acrylate film, onto which a wavy metastructure is added through 3D printing. This patterned layer controls the material’s mechanical response.

To introduce biological functionality, electrospun collagen fibers are applied on top. Tests showed that the structure closely reproduces the strain and strength behavior of natural-tissue. As the material stretches, the waves unfold to maintain flexibility, while stiffness increases at higher strain levels.

Biocompatibility Confirmed

Cell–material interaction studies confirmed that the material is biocompatible. Cytotoxicity tests showed no harmful effects on cells, and experiments with human fibroblasts and epithelial cells demonstrated strong cell adhesion and growth on the collagen fiber network.

The findings indicate that engineered materials can effectively combine mechanical performance with biological compatibility, enabling the development of advanced biomimetic implants.

Ready for Medical Technology Applications

The tissue substitute is adaptable to multiple medical applications, including artificial blood vessels, stent grafts, dura mater substitutes, and artificial skin. Researchers say the technology has reached a stage where it can move toward industrial development and product applications.

A joint patent has already been filed, and the team is seeking collaborations with medical technology companies to bring the innovation to market.

Source: Fraunhofer IAP