Modeling the fabrication process of micropatterned macromolecular scaffolds for peripheral nerve regeneration

Tubular scaffolds demonstrated to be able to reconnect the proximal and distal stumps of transected peripheral nerves and induce regeneration of the lost nerve trunk. Recently, a spinning technique has been developed, able to produce tubular collagen-based scaffolds characterized by a radially patterned microporosity. The technique is based on the centrifugal sedimentation of collagen taking place when a cylinder, containing an aqueous collagen suspension, is rotated rapidly around its axis. In this work, the centrifugation process was modeled by means of the Lamm differential equation for collagen concentration, with the assumption that sedimentation and diffusion coefficients were dependent on the local concentration, according to appropriate scaling laws. With such assumptions, the model was able to predict the actual tube formation and its inner radius, in good agreement with the experimental results. The possibility to predict the final scaffold inner diameter as a function of the processing parameters has a fundamental importance for the set up of a precise fabrication method, which does not make use of any complex mold. This would significantly reduce the production complexity and the extent of scaffold manipulation during production, resulting in a cleaner production process and safety of the device.