Biomaterial-engineering and neurobiological approaches for regenerating the injured cerebral cortex

Hippocampal acetylcholinesterase activation induced by streptozotocin in mice is protected by an organotellurium compound without evidence of toxicity

The cognitive deficit, which is like Alzheimer's disease and is associated with oxidative damage, may be induced by exposure to streptozotocin. This study aimed to evaluate if the tellurium-containing organocompound, 3j, 5'-arylchalcogeno-3-aminothymidine derivative, interferes with the effects of streptozotocin, as well as to investigate its toxicity in adult mice. Cognitive deficit was induced by two doses of streptozotocin (2.25 mg/kg/day, 48 h interval) intracerebroventricularly. After, the mice were subcutaneously treated with 3j (8.62 mg/kg/day) for 25 days. The effects were assessed by evaluating hippocampal and cortical acetylcholinesterase and behavioral tasks. 3j toxicity was investigated for 10 (0, 21.55, or 43.10 mg/kg/day) and 37 (0, 4.31, or 8.62 mg/kg/day) days by assessing biometric parameters and glucose and urea levels, and alanine aminotransferase activity in blood plasma. 3j exposure did not alter the behavioral alterations induced by streptozotocin exposure. On the other hand, 3j exposure normalized hippocampus acetylcholinesterase activity, which is enhanced by streptozotocin exposure. Toxicity evaluation showed that the administration of 3j for either 10 or 37 days did not cause harmful effects on the biometric and biochemical parameters analyzed. Therefore, 3j does not present any apparent toxicity and reverts acetylcholinesterase activity increase induced by streptozotocin in young adult mice.

The Role of Biomaterials in Implantation for Central Nervous System Injury

Permanent deficits that occur in memory, sensation, and cognition can result from central nervous system (CNS) trauma that causes dysfunction and/or unregulated CNS regeneration. Some therapeutic approaches are preferentially applied to the human body. Therefore, cell transplantation, one of the therapeutic strategies, may be used to benefit people. However, poor cell viability and low efficacy are the limitations to cell transplantation strategies. Biomaterials have been widely used in several fields (e.g., triggering cell differentiation, guiding cell migration, improving wound healing, and increasing tissue regeneration) by modulating their characteristics in chemistry, topography, and softness/stiffness for highly flexible application. We reviewed implanted biomaterials to investigate the roles and influences of physical/chemical properties on cell behaviors and applications. With their unique molecular features, biomaterials are delivered in several methods and mixed with transplanted cells, which assists in increasing postimplanted biological substance efficiency on cell survival, host responses, and functional recovery of animal models. Moreover, tracking the routes of these transplanted cells using biomaterials as labeling agents is crucial for addressing their location, distribution, activity, and viability. Here, we provide comprehensive comments and up-to-date research of the application of biomaterials.

Affinity-Immobilization of VEGF on Laminin Porous Sponge Enhances Angiogenesis in the Ischemic Brain

Ischemic brain stroke is caused by blood flow interruption, leading to focal ischemia, neuron death, and motor, sensory, and/or cognitive dysfunctions. Angiogenesis, neovascularization from existing blood vessel, is essential for tissue growth and repair. Proangiogenic therapy for stroke is promising for preventing excess neuron death and improving functional recovery. Vascular endothelial growth factor (VEGF) is a critical factor for angiogenesis by promoting the proliferation, the survival, and the migration of endothelial cells. Here, angiogenic biomaterials to support injured brain regeneration are developed. Porous laminin (LN)-rich sponge (LN-sponge), on which histidine-tagged VEGF (VEGF-Histag) is immobilized via affinity interaction is developed. In an in vivo mouse stroke model, transplanting VEGF-Histag-LN-sponge produces remarkably stronger angiogenic activity than transplanting LN-sponge with soluble VEGF. The findings indicate that using affinity interactions to immobilize VEGF is a practical approach for developing angiogenic biomaterials for regenerating the injured brain.