Two-component collagen nerve guides support axonal regeneration in the rat peripheral nerve injury model.

Progress in material development has enabled the production of nerve guides that increasingly resemble the characteristics of an autologous nerve graft. In the present study, 20 mm adult rat sciatic nerve defects were bridged with the collagen-based, two-component nerve guide 'Neuromaix', the commercially available NeuraGen® nerve tube or an autologous nerve graft. Neuromaix was able to support structural as well as functional regeneration across this gap. The majority of the axons grew across the scaffold into the distal nerve segment and retrograde tracing confirmed that these axons were of somatosensory and motor origin. Histomorphology revealed that axons regenerating through Neuromaix exhibited reduced myelin sheath thickness, whereas axon diameter and axon density were comparable to those of the autograft. Neuromaix implantation resulted in reinnervation of the gastrocnemius muscle to a level that was not significantly different from that supported by the autograft, as demonstrated by electrophysiology. Our findings show that the use of the Neuromaix scaffold not only allowed axonal regeneration across large nerve gaps, but that the regenerating axons were also able to functionally reinnervate the muscles. These data provide a promising perspective for the first in human application of the materials. Copyright © 2016 John Wiley & Sons, Ltd.

A new approach of in vivo musculoskeletal tissue engineering using the epigastric artery as central core vessel of a 3-dimensional construct.

The creation of musculoskeletal tissue represents an alternative for the replacement of soft tissue in reconstructive surgery. However, most of the approaches of creating artificial tissue have their limitations in the size as the maximally obtainable dimension of bioartificial tissue (BAT) is limited due to the lack of supporting vessels within the 3-dimensional construct. The seeded myoblasts require high amounts of perfusion, oxygen, and nutrients to survive. To achieve this, we developed a 3-dimensional scaffold which features the epigastric artery as macroscopic core vessel inside the BAT in a rat model (perfused group, n = 4) and a control group (n = 3) without the epigastric vessels and, therefore, without perfusion. The in vivo monitoring of the transplanted myoblasts was assessed by bioluminescence imaging and showed both the viability of the epigastric artery within the 3-dimensional construct and again that cell survival in vivo is highly depending on the blood supply with the beginning of capillarization within the BAT seven days after transplantation in the perfused group. However, further studies focussing on the matrix improvement will be necessary to create a transplantable BAT with the epigastric artery as anastomosable vessel.