CellStretch - UV light opens door to artificial tendons

With the aid of UV light, it was possible to significantly improve the cell compatibility of polymer films as support material for cell cultures. A model to grow artificial tendons for reconstructive medicine was created for the first time.

Short Description

Reconstructive medicine is already able to create artificial body tissue by means of tissue engineering. To control the growth of the tissue cells, medicine uses so-called cell stretchers. The cells are seeded onto polymer films, which serve as the substrate for the cell cultures that undergo mechanical resilience testing in the cell stretcher. Formerly, the obstacle encountered in this procedure was the polymer films’ limited cell compatibility.

This is the issue the industrial research project Cellstretch - a cooperation with university and ambitious, small companies - addresses. With the aid of ultraviolet irradiation, the researchers succeeded in making the surface of ductile polymer films biocompatible, so that they may be used as substrates during mechanical stimulation of the cells in a cell stretcher.

The films were irradiated in a reactive atmosphere using a Xe2* Excimer lamp in deep UV light, changing the chemical composition of the surface and making the films particularly hydrophilic (water-receptive). Thus, the polymer films’ cell compatibility was significantly improved.

Incubator for artificial tendons

As “proof of principle,” CellStretch developed an artificial tendon model. This project was also successful. The cell stretcher was modified in such a way that it can also be operated in a cell incubator. This makes oscillating stretching over several days possible, and cells extracted in skin biopsies can be aligned on the polymer surface and stimulated to produce collagen fibers such as those found in tendons.

Therefore CellStretch has succeeded in establishing, for the first time, a model to grow artificial tendons for reconstructive medicine. Moreover, the project achieved a record in that the resulting cell stretcher can be operated for several days or even weeks in a cell incubator, so that the cells can be stimulated mechanically much longer than in the past.

Project Partners


Johannes Kepler Universität Linz, Institut für Angewandte Physik

Weitere Konsortialpartner

  • Innerbichler GmbH
  • Innovacell Biotechnologie AG

Contact Address


a. Univ.-Prof. Dr. Johannes Heitz
E-mail: johannes.heitz@jku.at