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Current strategies for wound care provide limited relief to millions of patients who suffer from burns, chronic skin ulcers or surgical-related wounds. The goal of this work is to develop an in situ deposition of a personalized nanofibrous dressing via a handy electrospinning (e-spinning) device and evaluate its properties related to skin wound care. MCM-41 type mesoporous silica nanoparticles decorated with silver nanoparticles (Ag-MSNs) were prepared by a facile and environmentally friendly approach, which possessed long-term antibacterial activity and low cytotoxicity. Poly-ε-caprolactone (PCL) incorporated with Ag-MSNs was successfully electrospun (e-spun) into nanofibrous membranes. These in situ e-spun nanofibrous membranes allowed the continuous release of Ag ions and showed broad-spectrum antimicrobial activity against two common types of pathogens, Staphylococcus aureus and Escherichia coli. In addition, the in vivo studies revealed that these antibacterial nanofibrous membranes could reduce the inflammatory response and accelerate wound healing in Wistar rats. The above results strongly demonstrate that such patient-specific dressings could be broadly applied in emergency medical transport, hospitals, clinics and at the patients' home in the near future.

Extensive research has focused on transplantation of pluripotent stem cells for the treatment of central nervous system disorders, the therapeutic potential of stem cell therapy for injured peripheral nerves is largely unknown. We used a rat sciatic nerve transection model to test the ability of implanted embryonic stem (ES) cell-derived neural progenitor cells (ESNPCs) in promoting repair of a severely injured peripheral nerve. Mouse ES cells were neurally induced in vitro; enhanced expression and/or secretion of growth factors were detected in differentiating ES cells. One hour after removal of a 1-cm segment of the left sciatic nerve, ES-NPCs were implanted into the gap between the nerve stumps with the surrounding epineurium as a natural conduit. The transplantation resulted in substantial axonal regrowth and nerve repair, which were not seen in culture medium controls. One to 3 months after axotomy, co-immunostaining with the mouse neural cell membrane specific antibody M2/M6 and the Schwann cell marker S100 suggested that transplanted ES-NPCs had survived and differentiated into myelinating cells. Regenerated axons were myelinated and showed a uniform connection between proximal and distal stumps. Nerve stumps had near normal diameter with longitudinally oriented, densely packed Schwann celllike phenotype. Fluoro-Gold retrogradely labeled neurons were found in the spinal cord (T12-13) and DRG (L4-L6), suggesting reconnection of axons across the transection. Electrophysiological recordings showed functional activity recovered across the injury gap. These data suggest that transplanted neurally induced ES cells differentiate into myelin-forming cells and provide a potential therapy for severely injured peripheral nerves.