RESUMO
As a special kind of in vitro diagnostic devicesï¼IVDsï¼, laboratory developed testsï¼LDTsï¼ are of great significance to the development of clinical laboratories. This study aims to explore the regulatory requirements ideas of LDTs. By introducing the development of LDTs and the changing of regulatory requirements in the United States, combing the current regulatory framework and discussing relevant ideas in the regulatory requirements of LDTs.
Assuntos
Serviços de Laboratório Clínico , Laboratórios , Kit de Reagentes para Diagnóstico , Estados Unidos , United States Food and Drug AdministrationRESUMO
To review the registration and technical data for prenatal diagnosis of chromosome aneuploidy by next generation sequencing technology. On the basis of introducing declarations of the reagents, analysis registration dossier common problems. And analysis the requirement of performance evaluation, reference intervals and clinical evaluation study.
Assuntos
Aneuploidia , Sequenciamento de Nucleotídeos em Larga Escala , Diagnóstico Pré-Natal/normas , Feminino , Humanos , GravidezRESUMO
This paper aims to analysis of the general problem in the registration dossier and make recommendations on in vitro diagnostic device of tumor markers. On the basis of introducing declarations of the reagents, analysis registration dossier common problems occurs in the products intend to detect novel tumor markers and the combined detection product for multiple tumor markers, and analysis the special requirements for such products.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias/diagnóstico , Kit de Reagentes para Diagnóstico/normas , HumanosRESUMO
Nanofibrous scaffold of carbon nanotubes/polyurethane composite (MWNT/PU) with aligned topography was fabricated by electrospinning for endothelium cells growth. The diameter of the generated fiber was around 300 nm-500 nm. Experimental results indicated that the nanofibrous scaffold of MWNT/PU exhibited promotional influence on the cell proliferation. It was also observed that the scaffold possessed an advantage of supporting ECs migrating and aggregating along the axis of the aligned nanofibers, which is one of the important functions in the process of endothelium regeneration. It was also demonstrated that the endothelial cells growing on the scaffold expressed non-thrombogenic phenotype with low tissue factor released. These results indicated the favorable interactions between ECs and the nanofibrous scaffold of MWNT/PU, implying that the aligned nanofibrous scaffold has a promising potential for vascular engineering.
Assuntos
Endotélio/citologia , Nanoestruturas , Nanotubos de Carbono , Poliuretanos/química , Engenharia TecidualRESUMO
Dynamic culture conditions serve as a critical factor in constructing physiologically functional blood vessel substitutes. With the development of tissue engineering, many experiments have verified the hypothesis that proper dynamic conditions are important for cells' behaving ways such as attachment, proliferation, differentiation and the remodeling of the extracellular matrix. By means of simulating the physiological dynamic conditions, one can enhance cell growth and extracellular matrix remodeling, and further improve the function of engineered vessel. In this paper is reviewed the current state of dynamic culture conditions provided for tissue engineering vessel graft, including the effects of different dynamic culture conditions on the proliferation of vascular cells and the remodeling of extracellular matrix. The use of bioreactor in constructing tissue engineering blood vessels and the effects of dynamic culture environments are also discussed with respect to the biological properties of vascular grafts.
Assuntos
Reatores Biológicos , Prótese Vascular , Técnicas de Cultura de Células/métodos , Artéria Pulmonar/citologia , Engenharia Tecidual/métodos , Animais , Fenômenos Biomecânicos , Adesão Celular , Diferenciação Celular , Células Cultivadas , CoelhosRESUMO
Aligned or random nanofibrous meshes of multiwalled carbon nanotubes/polyurethane composite (MWCNT/PU) were fabricated by electrospinning and characterized by scanning electron microscopy (SEM). The regulatory effects of nanofibrous structure and MWCNT on the growth and anticoagulant function of human umbilical vein endothelial cells (HUVECs) were investigated by examining proliferation, type IV collagen secretion, tissue factor and plasminogen activator inhibitor-1 (PAI-1) release, and cytoskeleton arrangement, as well as via pull-down analysis. We show that aligned nanofibrous structure and MWCNT can function as extracellular signals to stimulate cell growth, proliferation, and extracellular collagen secretion, in addition to preserving anticoagulant function. The nanofibrous structures played important roles in the activation of Rac and Cdc42, while CNT regulated the activation of Rho. These two features synergistically activated Rho GTPases that transmitted cell-substrate signals to the cytoplasm. These signals were then relayed to the nucleus by the MAP kinase pathway to direct cytoskeletal arrangement and cell orientation.
Assuntos
Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Nanofibras/química , Nanotubos de Carbono/química , Poliuretanos/farmacologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Anticoagulantes/metabolismo , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Colágeno Tipo IV/metabolismo , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Células Endoteliais/enzimologia , Células Endoteliais/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Laminina/metabolismo , Nanofibras/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Tromboplastina/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
In this work, the effect of nanofibrous structure and multiwalled carbon nanotubes (MWNTs) incorporation in the polyurethane (PU) on the fibroblasts growth behavior was studied. The nanofibrous scaffold of multiwalled carbon nanotubes and polyurethane composite (MWNT/PU) with an average fiber diameter of 300-500 nm was fabricated by electrospinning technique. The nanofibrous scaffold of PU, smooth film of PU, and MWNT/PU were also prepared as controls. Cell viability assay, laser confocal microscopy, and scanning electron microscopy were applied to evaluate cell adhesion, proliferation, and cytoskeletal development on the scaffolds, respectively. Cell-released protein was analyzed by Bradford protein assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), mass spectrometry, and transwell assay, respectively. Experimental results demonstrated that the scaffold with nanofibrous structure and MWNTs incorporation exhibited highest enhancement not only to the cell adhesion and proliferation but also to the cell migration and aggregation. Besides, cells cultured on the nanofibrous scaffold of MWNT/PU released the largest amount of proteins including collagen in comparison with those on the other substrates. Hence, the nanofibrous architecture and MWNTs incorporation provided favorite interactions to the cells, which implied the application potentials of the nanofibrous composite for tissue repair and regeneration.