RGD-Modified Nanofibers Enhance Outcomes in Rats after Sciatic Nerve Injury

Abstract

Nerve injuries requiring surgery are a significant problem without good clinical alternatives to the autograft. Tissue engineering strategies are critically needed to provide an alternative. In this study, we utilized aligned nanofibers that were click-modified with the bioactive peptide RGD for rat sciatic nerve repair. Empty conduits or conduits filled with either non-functionalized aligned nanofibers or RGD-functionalized aligned nanofibers were used to repair a 13 mm gap in the rat sciatic nerve of animals for six weeks. The aligned nanofibers encouraged cell infiltration and nerve repair as shown by histological analysis. RGD-functionalized nanofibers reduced muscle atrophy. During the six weeks of recovery, the animals were subjected to motor and sensory tests. Sensory recovery was improved in the RGD-functionalized nanofiber group by week 4, while other groups needed six weeks to show improvement after injury. Thus, the use of functionalized nanofibers provides cues that aid in in vivo nerve repair and should be considered as a future repair strategy.

Fabrication of Biomedical Scaffolds Using Biodegradable Polymers

“…Synthetic polymers, on the other hand, do not possess specific cell adhesion sequences and are often passivated using physiologic proteins to facilitate cell adhesion or they need to be extensively functionalized, for instance, through the addition of RGD sequences or other biologically active moieties. This has frequently been done for synthetic hydrogels, such as PEG and PVA, , as well as other synthetic polymers, such as PCL. , Aside from the RGD peptide, the Tyr-Ile-Gly-Ser-Arg (YIGSR) peptide derived from laminin, was also shown to promote cell attachment and laminin receptor binding and was used to functionalize PLLA nanofiber scaffolds …”

Repair of Peripheral Nerve Injury Using Hydrogels Based on Self-Assembled Peptides

“…IKVAV can promote the adhesion, differentiation, and axon growth of neurons in the injured peripheral nerve area, inhibit the adhesion and differentiation of glial cells, and simulate the appropriate microenvironment needed for nerve cell growth during the process of peripheral nerve repair [23]. RGD and YIGSR can promote cell adhesion [24][25][26][27]. A self-assembled peptide was designed by Professor Zhai to better control the mechanical strength of the matrix and RGD concentrations, reaching conditions close to those in the extracellular matrix [28].…”

Next Stage Approach to Tissue Engineering Skeletal Muscle

“…During scaffold fabrication, the structural properties of the scaffold can be further fine-tuned by functionalizing with RGD [ 44 ] or crosslinking with molecules [ 45 ] nanoparticles [ 46 , 47 ] and proteins such as laminin [ 8 , 48 ]. The protein fiber length, pore size, orientation and stiffness [ 49 ], to name a few, demonstrate the infinite variables to be considered.…”