Novel conductive polypyrrole/silk fibroin scaffold for neural tissue repair.

Three dimensional (3D) bioprinting, which involves depositing bioinks (mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration.

A partition-type tubular scaffold loaded with PDGF-releasing microspheres for spinal cord repair facilitates the directional migration and growth of cells.

The best tissue-engineered spinal cord grafts not only match the structural characteristics of the spinal cord but also allow the seed cells to grow and function in situ. Platelet-derived growth factor (PDGF) has been shown to promote the migration of bone marrow stromal cells; however, cytokines need to be released at a steady rate to maintain a stable concentration in vivo. Therefore, new methods are needed to maintain an optimal concentration of cytokines over an extended period of time to effectively promote seed cell localization, proliferation and differentiation.

The High-Frequency Ultrasound Detection of Rat Sciatic Nerve in a Crushed Injury Model.

Objective: This study aimed to visualize sciatic nerve injury in rats using ultrasound imaging in a crushed injury model.

Methods: Adult male Sprague-Dawley rats were subjected to a left sciatic nerve crush operation. Then, high-frequency ultrasound was used to image both sciatic nerves at 2 days and at 1, 2, 3, 4, and 6 weeks after surgery.

The Effect of Low-Intensity Ultrasound on Brain-Derived Neurotropic Factor Expression in a Rat Sciatic Nerve Crushed Injury Model.

Low-intensity ultrasound (LIU) can improve nerve regeneration and functional recovery after peripheral nerve crush injury, but the underlying mechanism is not clear. The objective of this study was to examine the effects of LIU on rat sciatic crush injury and to investigate a possible molecular mechanism. Adult male Sprague-Dawley rats underwent left sciatic nerve crush surgery and were then randomized into two groups: a treatment group that received LIU every other d, and a control group that received sham exposure.

Angiogenesis in tissue-engineered nerves evaluated objectively using MICROFIL perfusion and micro-CT scanning.

Angiogenesis is a key process in regenerative medicine generally, as well as in the specific field of nerve regeneration. However, no convenient and objective method for evaluating the angiogenesis of tissue-engineered nerves has been reported. In this study, tissue-engineered nerves were constructed in vitro using Schwann cells differentiated from rat skin-derived precursors as supporting cells and chitosan nerve conduits combined with silk fibroin fibers as scaffolds to bridge 10-mm sciatic nerve defects in rats.

Controlling the release of bFGF from silk fibroin membrane.

Since neurotrophic factor is easy to degrade and aggregate, it usually has a short half-life in vitro. To overcome this shortage, neurotrophic factor has been combined with the silk fibroin (SF) membrane to realize less degradation, optimal loading efficiency, sustained release, and good adsorption. By optimizing its binding conditions, main parameters were investigated and its optimal loading efficiency was obtained.

Nanoparticle mediated controlled delivery of dual growth factors.

Peripheral nerve functional recovery after nerve injury generally requires multiple growth factors by synergistic effect. However, the optical combination of multiple synergistic growth factors for axonal regeneration has been scarcely considered up to now. Meanwhile, the use of growth factors in promoting nerve regeneration was limited by its short biological half-life in vivo, its vulnerability to structure disruption or hydrolyzation, leading to loss of bioactivity.