Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( ...Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( PBS) and silk fibroin(SF) to produce fiber-based finely tuned porous architectures by weft and warp knittings. The obtained knitted constructs are described in terms of their morphology, mechanical properties,swelling ability,degradation behaviour,and cytotoxicity. Each type of polymer fibers allows for the processing of a very reproducible intra-architectural scaffold geometry,with distinct characteristics in terms of the surface physicochemistry,mechanical performance,and degradation capability,which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening shows that both materials can support cell adhesion and proliferation. Furthermore, different surface modifications were performed( acid /alkaline treatment, UV radiation,and plasma) for modulating cell behavior. An increase of cell-material interactions were observed,indicating the important role of materials surface in the first hours of culturing. Human adipose-derived stem cells( hASCs) became an emerging possibility for regenerative medicine and tissue replacement therapies. The potential of the recently developed silk-based biotextile structures to promote hASCs adhesion,proliferation,and differentiation is also evaluated. The obtained results validate the developed constructs as viable matrices for TE applications. Given the processing efficacy and versatility of the knitting technology, and the interesting structural and surface properties of the proposed polymer fibers,it is foreseen that our developed systems can be attractive for the functional engineering of tissues such as bone,skin,ligaments or cartilage and also for develop more complex systems for further industrialization of TE products.展开更多
In the last years,much work has shown that the most effective repair system of the body is represented by stem cells,which are defined as undifferentiated precursors that own unlimited or prolonged self-renewal abilit...In the last years,much work has shown that the most effective repair system of the body is represented by stem cells,which are defined as undifferentiated precursors that own unlimited or prolonged self-renewal ability,which also have the potential to transform themselves into various cell types through differentiation.All tissues that form the body contain many different types of somatic cells,along with stem cells that are called‘mesenchymal stem(or stromal)cells’(MSC).In certain circumstances,some of these MSC migrate to injured tissues to replace dead cells or to undergo differentiation to repair it.The discovery of MSC has been an important step in regenerative medicine because of their high versatility.Moreover,the finding of a method to isolate MSC from adipose tissue,so called‘adipose-derived mesenchymal stem cells’(ASC),which share similar differentiation capabilities and isolation yield that is greater than other MSC,and less bioethical concerns compared to embryonic stem cells,have created self-praised publicity to procure almost any treatment with them.Here,we review the current techniques for isolation,culture and differentiation of human ASC(hASC),and describe them in detail.We also compile some advantages of the hASC over other stem cells,and provide some concepts that could help finding strategies to promote their therapeutic efficiency.展开更多
Administrative units reflect the territorial hierarchies established within all countries of the world.The units are addressable with geocodes that provide a bijective mapping between territories and unique identifica...Administrative units reflect the territorial hierarchies established within all countries of the world.The units are addressable with geocodes that provide a bijective mapping between territories and unique identification codes.Early warning systems for natural or man-made hazards often map affected or threatened areas to administrative units to establish a spatial reference that is comprehensible to all parts of the population.Addressing these territories in an international context has several requirements,such as worldwide coverage,completeness and topicality,which must be met by geocode standards.In this paper,the practicability and suitability of international geocode standards are examined in the context of the requirements of large-scale early warning systems.This paper exposes the insufficiencies and limitations of existing geocode standards International Organization for Standardization(ISO)-3166,Second Administrative Level Boundaries data set project(SALB)and Nomenclature of the Territorial Units for Statistics(NUTS)and emphasises the suitability of the non-official hierarchical administrative subdivision codes(HASC).The analysis is framed in the context of addressing affected areas for an Indian Ocean tsunami early warning system.This system was developed within the Distant Early Warning Systems project according to the requirements of the United Nations Educational,Scientific and Cultural Organization(UNESCO)Intergovernmental Oceanic Commission for Regional Tsunami Watch Providers(RTWPs).展开更多
文摘Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( PBS) and silk fibroin(SF) to produce fiber-based finely tuned porous architectures by weft and warp knittings. The obtained knitted constructs are described in terms of their morphology, mechanical properties,swelling ability,degradation behaviour,and cytotoxicity. Each type of polymer fibers allows for the processing of a very reproducible intra-architectural scaffold geometry,with distinct characteristics in terms of the surface physicochemistry,mechanical performance,and degradation capability,which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening shows that both materials can support cell adhesion and proliferation. Furthermore, different surface modifications were performed( acid /alkaline treatment, UV radiation,and plasma) for modulating cell behavior. An increase of cell-material interactions were observed,indicating the important role of materials surface in the first hours of culturing. Human adipose-derived stem cells( hASCs) became an emerging possibility for regenerative medicine and tissue replacement therapies. The potential of the recently developed silk-based biotextile structures to promote hASCs adhesion,proliferation,and differentiation is also evaluated. The obtained results validate the developed constructs as viable matrices for TE applications. Given the processing efficacy and versatility of the knitting technology, and the interesting structural and surface properties of the proposed polymer fibers,it is foreseen that our developed systems can be attractive for the functional engineering of tissues such as bone,skin,ligaments or cartilage and also for develop more complex systems for further industrialization of TE products.
基金supported by grants from ANPCyT(PICT-141659)CONICET(PIP-13CO01),SeCTyP-UNCuyo(J051)the Roemmers Foundation.DM,MU and DMB are members of CONICET.YRFL and ADG,are fellows of the same institution.
文摘In the last years,much work has shown that the most effective repair system of the body is represented by stem cells,which are defined as undifferentiated precursors that own unlimited or prolonged self-renewal ability,which also have the potential to transform themselves into various cell types through differentiation.All tissues that form the body contain many different types of somatic cells,along with stem cells that are called‘mesenchymal stem(or stromal)cells’(MSC).In certain circumstances,some of these MSC migrate to injured tissues to replace dead cells or to undergo differentiation to repair it.The discovery of MSC has been an important step in regenerative medicine because of their high versatility.Moreover,the finding of a method to isolate MSC from adipose tissue,so called‘adipose-derived mesenchymal stem cells’(ASC),which share similar differentiation capabilities and isolation yield that is greater than other MSC,and less bioethical concerns compared to embryonic stem cells,have created self-praised publicity to procure almost any treatment with them.Here,we review the current techniques for isolation,culture and differentiation of human ASC(hASC),and describe them in detail.We also compile some advantages of the hASC over other stem cells,and provide some concepts that could help finding strategies to promote their therapeutic efficiency.
基金the DEWS Project funded by the sixth Framework Programme of the European Commission(contract number 045453).
文摘Administrative units reflect the territorial hierarchies established within all countries of the world.The units are addressable with geocodes that provide a bijective mapping between territories and unique identification codes.Early warning systems for natural or man-made hazards often map affected or threatened areas to administrative units to establish a spatial reference that is comprehensible to all parts of the population.Addressing these territories in an international context has several requirements,such as worldwide coverage,completeness and topicality,which must be met by geocode standards.In this paper,the practicability and suitability of international geocode standards are examined in the context of the requirements of large-scale early warning systems.This paper exposes the insufficiencies and limitations of existing geocode standards International Organization for Standardization(ISO)-3166,Second Administrative Level Boundaries data set project(SALB)and Nomenclature of the Territorial Units for Statistics(NUTS)and emphasises the suitability of the non-official hierarchical administrative subdivision codes(HASC).The analysis is framed in the context of addressing affected areas for an Indian Ocean tsunami early warning system.This system was developed within the Distant Early Warning Systems project according to the requirements of the United Nations Educational,Scientific and Cultural Organization(UNESCO)Intergovernmental Oceanic Commission for Regional Tsunami Watch Providers(RTWPs).
