Microfluidic three-dimensional cell culture of stem cells for high-throughput analysis

Although the recent advances in stem cell engineering have gained a great deal of attention due to their high potential in clinical research,the applicability of stem cells for preclinical screening in the drug discovery process is still challenging due to difficulties in controlling the stem cell microenvironment and the limited availability of high-throughput systems.Recently,researchers have been actively developing and evaluating three-dimensional(3D)cell culture-based platforms using microfluidic technologies,such as organ-on-a-chip and organoid-on-a-chip platforms,and they have achieved promising breakthroughs in stem cell engineering.In this review,we start with a comprehensive discussion on the importance of microfluidic 3D cell culture techniques in stem cell research and their technical strategies in the field of drug discovery.In a subsequent section,we discuss microfluidic 3D cell culture techniques for high-throughput analysis for use in stem cell research.In addition,some potential and practical applications of organ-on-a-chip or organoid-on-a-chip platforms using stem cells as drug screening and disease models are highlighted.

Effect of Graphene Nanoribbons (TexasPEG) on locomotor function recovery in a rat model of lumbar spinal cord transection

A sharply transected spinal cord has been shown to be fused under the accelerating influence of membrane fusogens such as polyethylene glycol （PEG） （GEMINI protocol）. Previous work provided evidence that this is in fact possible. Other fusogens might improve current results. In this study, we aimed to assess the effects of PEGylated graphene nanoribons （PEG-GNR, and called ＂TexasPEG＂ when prepared as lwt% dispersion in PEG600） versus placebo （saline） on locomotor function recovery and cellular level in a rat model of spinal cord transection at lumbar segment 1 （L1） level. In vivo and in vitro experiments （n -- 10 per experiment） were designed. In the in vivo experiment, all rats were submitted to full spinal cord transection at L1 level. Five weeks later, behavioral assessment was performed using the Basso Beattie Bresnahan （BBB） locomotor rating scale. Immunohistochemical staining with neuron marker neurofilament 200 （NF200） antibody and astrocyt- ic scar marker glial fibrillary acidic protein （GFAP） was also performed in the injured spinal cord. In the in vitro experiment, the effects of TexasPEG application for 72 hours on the neurite outgrowth of SH-SYSY cells were observed under the inverted microscope. Results of both in vivo and in vitro experiments suggest that TexasPEG reduces the formation of glial scars, promotes the regeneration of neurites, and thereby contributes to the recovery of locomotor function of a rat model of spinal cord transfection.

利用载体基因增强电介导基因传递的研究

在临床治疗中,靶基因的低转染和表达一直是基因传递中的一个重要问题。本研究提出了一种用载体基因电穿孔增强靶基因转染效率的方法。为了检测转染效率,试验用荧光基因(pGL3-control)转染HeLa细胞,用原核表达载体pCR2.1作为电介导基因传递的一个载体基因,对荧光素酶活性进行了测定。结果表明,在载体基因的作用下,荧光素酶基因成功转入细胞膜内,且有载体基因的荧光素酶活性是无载体基因的2～3倍。此外,试验还通过计算荧光素酶基因/载体基因的比值分析了其转染效率,发现两者之间无显著差异。因此,在生物学研究中,载体基因的使用有利于增强靶基因的转染和表达。