A biocompatible gelatin sponge scaffold confers robust tissue remodeling after spinal cord injury in a non-human primate model.

We previously constructed a three-dimensional gelatin sponge (3D-GS) scaffold as a delivery vehicle for therapeutic cells and trophic factors in the treatment of spinal cord injury (SCI), and this study aimed to assess the biosafety and efficacy of the scaffold in a non-human primate SCI model. However, because it has only been tested in rodent and canine models, the biosafety and efficacy of the scaffold should ideally be assessed in a non-human primate SCI model before its use in the clinic. No adverse reactions were observed over 8 weeks following 3D-GS scaffold implantation into in a Macaca fascicularis with hemisected SCI. Scaffold implantation also did not add to neuroinflammatory or astroglial responses already present at the injured site, suggesting good biocompatibility. Notably, there was a significant reduction in α-smooth muscle actin (αSMA)-positive cells at the injury/implantation interface, leading to alleviation of fibrotic compression of the residual spinal cord tissue. The regenerating tissue in the scaffold showed numerous cells migrating into the implant secreting abundant extracellular matrix, resulting in a pro-regenerative microenvironment. Consequently, nerve fiber regeneration, myelination, vascularization, neurogenesis, and electrophysiological improvements were achieved. These results indicated that the 3D-GS scaffold had good histocompatibility and effectiveness in the structural repair of injured spinal cord tissue in a non-human primate and is suitable for use in the treatment of patients with SCI.

A novel three-dimensional flow-through graphite felt-matrix cathode for in-situ hydrogen peroxide generation in multi-environment systems-Multiphysics modeling for in-situ hydrogen peroxide generation.

In order to achieve in-situ H2O2 generation in multi-environment systems, polyvinylpyrrolidone (PVP) and modified carbon nitride (t-g-C3N4) are co-doped onto graphite felt-matrix (GF-matrix) by electrodeposition to develop a novel cathode electrode. By means of 3D-X-ray CT, High-Resolution Transmission Electron Microscope (HRTEM), X-ray Photoelectron Spectrometer (XPS), Raman and Electrochemical Workstation, microscopic physical-chemical properties of materials are researched to optimize the electrode structure. Results show that the optimal electrode presents over H2O2 production rate of 2000 mgL-1·h-1, and as high as current efficiency of 93% to 98% in simulated freshwater (50 mM Na2SO4, pH = 1-12) at 20 mAcm-2. Furthermore, we built an original three-dimensional (3D) flow-through GF-matrix cathode model on H2O2 generation in simulated freshwater, explaining solution pH change reasons from solution inlet to outlet.