The effect of the fibre orientation of electrospun scaffolds on the matrix production of rabbit annulus fibrosus-derived stem cells

Annulus fibrosus （AF） tissue engineering has recently received increasing attention as a treatment for intervertebral disc 0VD） degeneration; however, such engineering remains challenging because of the remarkable complexity of AF tissue. In order to engineer a functional AF replacement, the fabrication of cell-scaffold constructs that mimic the cellular, biochemical and structural features of native AF tissue is critical. In this study, we fabricated aligned fibroua polyurethane scaffolds using an electrospinning technique and used them for culturing AF-derived-stem/progenitor cells （AFSCs）. Random fibrous scaffolds, also prepared via electrospinningy were used as a control. We compared the morphology, proliferation, gene expression and matrix production of AFSCs on aligned scaffolds and random scaffolds. There was no apparent difference in the attachment or proliferation of cells cultured on aligned scaffolds and random scaffolds. However, compared to cells on random scaffolds, the AFSCs on aligned scaffolds were more elongated and better aligned, and they exhibited higher gene expression and matrix production of coUagen-I and aggrecan. The gene expression and protein production of coUagen-II did not appear to differ between the two groups. Together, these findings indicate that aligned fibrous scaffolds may provide a favourable microenvironment for the differentiation of AFSCs into cells similar to outer AF cells, which predominantly produce collagen-I matrix.

Brain repair for Parkinson's disease:is the answer in the matrix?

Two hundred years after James Parkinson first described the cardinal motor symptoms of the disorder that would later bear his name,there is still an irrefutable need for a therapy that targets the underlying pathophysiology of the disease and not solely its symptoms.

Regulation of ovarian function by the matrix metalloproteinase system

In most organs of mammals, cyclic remodelling of tissues after morphogenesis is minimal; however, reproductive tissues of female animals including endometrium, mammary gland, ovarian follicle and corpus luteum undergo growth, maturation and involution at various stages in the reproductive cycle or lifespan of the animal. Reconstruction of the extracellular matrix (ECM) is required for the dynamic tissue reorganization characteristic of these tissues. The ECM consists of proteinaceous and nonproteinaceous molecules that provide the tissue-specific, extracellular architecture to which cells attach. Furthermore, interaction of cellular receptors with proteins of the ECM can regulate cellular structure, second messenger generation and gene expression. Mainte-

Parallel VLSI design for the fast 3-D DWT core algorithm

By studying the core algorithm of a three-dimensional discrete wavelet transform(3-D DWT)in depth,this paper divides it into three one-dimensional discrete wavelet transforms(1-D DWTs).Based on the implementation of a 3-D DWT software,a parallel architecture design of a very large-scale integration(VLSI)is produced.It needs three dual-port random-access memory(RAM)to store the temporary results and transpose the matrix,then builds up a pipeline model composed of the three 1-D DWTs.In the design,the finite state machine(FSM)is used well to control the flow.Compared with the serial mode,the experimental results of the post synthesized simulation show that the design method is correct and effective.It can increase the processing speed by about 66%,work at 59 MHz,and meet the real-time needs of the video encoder.

Determination of N-nitrosodimethylamine in drinking water by UPLC-MS/MS

The method for detecting N-nitrosodimethylamine （NDMA） in drinking water using ultra performance liquid chromatography （UPLC） coupled with tandem mass spectrometry （MS/MS） was improved by optimizing the clean-up procedure to remove the matrix interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68 to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment.