Femke Mathot

Chapter 10 178 Figure 1. Illustration of the hypothesized synergistic effect on axon regeneration between surgical angiogenesis and MSC-seeding. Local delivery of Tacrolimus would therefore be ideal. 71 Hydrogel is described to facilitate this local delivery, containing microspheres that encapsulate Tacrolimus. 72 Hydrogel delivery of Tacrolimus has resulted in improved in vitro and in vivo outcomes after peripheral nerve repair 73 , but uncertainties like its mechanism of action, ideal dosage, duration of treatment and their interaction with MSCs remain to be studied before clinical translation can be considered. 74 Cell delivery Besides factors like Tacrolimus, NGF and BDNF 75 , microspheres have shown to be able to encapsulate MSCs 76 , potentially facilitating local delivery of MSCs to regenerating nerves. Since MSC-delivery in peripheral nerve repair is a rather underexposed research topic, it would be interesting to directly compare delivery efficiencies of different strategies like MSC- injection and microsphere encapsulation to that of dynamic seeding. IN CONCLUSION Contemplating the described outcomes, correlations and limitations, the chapters of this thesis have demonstrated that undifferentiated and differentiated MSCs can be efficiently seeded onto processed nerve allografts. Both cell types can interact with the extracellular matrix of processed nerve allografts, mostly leading to an upregulation of neurotrophic, angiogenic and extracellular matrix genes. Compared to unseeded processed nerve