Bioengineered glial strands for nerve regeneration.

Nerve guide implants approved for human application in the peripheral nervous system generally fail to bridge lesion gaps longer than 2 cm and cannot match the clinical performance of autologous nerve transplants. Since current synthetic implants are simply hollow tubes, we aim to recreate the native microarchitecture of nerves inside the tubular implants. Most importantly, in the regenerating nerve, dedifferentiated Schwann cells align to form thousands of long glial strands, which act as guiding structures for the regrowing axons.

A novel gelatin sponge for accelerated hemostasis.

To more effectively manage the substantial bleeding encountered during surgical procedures in oto-rhino-laryngology, we developed a novel hemostatic sponge made of pharmaceutical grade, chemically cross-linked gelatin. The sponge is characterized by a high pore density, reduced ligaments, and a high nanoscale roughness of lamella surfaces in the matrix. In vitro blood uptake assays revealed a very rapid absorption of human blood, which was two to three times faster than that measured with comparative hemostyptic devices.

A novel microsurgical nerve implantation technique preserving outer nerve layers.

A novel epineural tube implantation paradigm in the adult rat was designed for the analysis of regulatory cell interactions in peripheral nerves and for the development of therapeutic implants. The aim was to allow the integration of synthetic regenerative structures and cells into the nerve interior while preserving an outer nerve tissue layer with a supportive vasculature. The microsurgical technique allowed us to remove the interfascicular epineurium, leaving behind an epineural tube with an intact tissue wall of about 0.

Permeability testing of biomaterial membranes.

The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts.