Enhanced Protein Adsorption,Cell Attachment,and Neural Differentiation with the Help of Amine Functionalized Polycaprolactone Scaffolds

Today, neurodegenerative diseases are very common among people. As a result, researchers are investigating methods for treatment of these diseases. One therapeutic approach is differentiating stem cells into neural cells to replace damaged areas of the brain. Cell attachment is the first, necessary step for the process of differentiation. Hence, we tried to enhance cell adhesion and proliferation of bone marrow stem cells on poly(?-caprolactone) (PCL) scaffolds through modifying this substrate with amine functional groups. The presence of amine groups was confirmed by Fourier transform infrared spectrometry (FTIR). Protein adsorption was measured at 280 nm via UV-spectrometry. The proliferation of differentiated neurons was assessed by 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (a dye) and cresyl violet staining. Finally, the morphology of differentiated neurons was shown by scanning electron microscopy (SEM). Results showed that amine modification of PCL scaffolds enhanced protein absorption and, consequently, cell adhesion and proliferation.     

A priming role of local estrogen on exogenous estrogen-mediated synaptic plasticity and neuroprotection

The localization of estrogen (E2) has been clearly shown in hippocampus, called local hippocampal E2. It enhanced neuronal synaptic plasticity and protected neuron form cerebral ischemia, similar to those effects of exogenous E2. However, the interactive function of hippocampal and exogenous E2 on synaptic plasticity activation and neuroprotection is still elusive. By using hippocampal H19-7 cells, we demonstrated the local hippocampal E2 that totally suppressed by aromatase inhibitor anastrozole. Anastrozole also suppressed estrogen receptor (ER)β, but not ERα, expression. Specific agonist of ERα (PPT) and ERβ (DPN) restored ERβ expression in anastrozole-treated cells. In combinatorial treatment with anastrozole and phosphoinositide kinase-3 (PI-3K) signaling inhibitor wortmannin, PPT could not improve hippocampal ERβ expression. On the other hand, DPN induced basal ERβ translocalization into nucleus of anastrozole-treated cells. Exogenous E2 increased synaptic plasticity markers expression in H19-7 cells. However, exogenous E2 could not enhance synaptic plasticity in anastrozoletreated group. Exogenous E2 also increased cell viability and B-cell lymphoma 2 (Bcl2) expression in H(2)O(2)-treated cells. In combined treatment of anastrozole and H(2)O(2), exogenous E2 failed to enhance cell viability and Bcl2 expression in hippocampal H19-7 cells. Our results provided the evidence of the priming role of local hippocampal E2 on exogenous E2-enhanced synaptic plasticity and viability of hippocampal neurons.     

参数未知神经元模型的全阶与降阶最优同步

基于Lyapunov稳定性理论、最优控制原理以及分步设计方法, 为神经元系统设计了非线性反馈控制器和最优控制器. 其中非线性反馈控制器能使得两个神经元系统之间的轨道误差趋于零, 最优控制器使得在同步过程中所花费的能量达到最低. 本文以Cable模型为例, 实现了两个神经元模型的全阶最优同步; 以Cable 模型和Hindmarsh-Rose (HR)模型为例, 实现了两个神经元模型的降阶最优同步; 同时, 均能有效地辨识出系统参数. 最后通过数值模拟进一步验证了本方案的有效性.     

Influence of 40 Hz and 100 Hz Vibration on SH-SY5Y Cells Growth and Differentiation—A Preliminary Study

(1) Background: A novel bioreactor platform of neuronal cell cultures using low-magnitude, low-frequency (LMLF) vibrational stimulation was designed to discover vibration influence and mimic the dynamic environment of the in vivo state. To better understand the impact of 40 Hz and 100 Hz vibration on cell differentiation, we join biotechnology and advanced medical technology to design the nano-vibration system. The influence of vibration on the development of nervous tissue on the selected cell line SH-SY5Y (experimental research model in Alzheimer’s and Parkinson’s) was investigated. (2) Methods: The vibration stimulation of cell differentiation and elongation of their neuritis were monitored. We measured how vibrations affect the morphology and differentiation of nerve cells in vitro. (3) Results: The highest average length of neurites was observed in response to the 40 Hz vibration on the collagen surface in the differentiating medium, but cells response did not increase with vibration frequency. Also, vibrations at a frequency of 40 Hz or 100 Hz did not affect the average density of neurites. 100 Hz vibration increased the neurites density significantly with time for cultures on collagen and non-collagen surfaces. The exposure of neuronal cells to 40 Hz and 100 Hz vibration enhanced cell differentiation. The 40 Hz vibration has the best impact on neuronal-like cell growth and differentiation. (4) Conclusions: The data demonstrated that exposure to neuronal cells to 40 Hz and 100 Hz vibration enhanced cell differentiation and proliferation. This positive impact of vibration can be used in tissue engineering and regenerative medicine. It is planned to optimize the processes and study its molecular mechanisms concerning carrying out the research.