In this work, we have considered a new multimodality imaging for macroscopy based on Second Harmonic Generation (SHG) method to monitor invasivelessly the matrix collagen. As the triple helicoidally structure of colla...In this work, we have considered a new multimodality imaging for macroscopy based on Second Harmonic Generation (SHG) method to monitor invasivelessly the matrix collagen. As the triple helicoidally structure of collagen molecules appearing as not centrosymetric, very organized and spatially oriented, collagen fibrils give rise to a very strong SHG signal and can be imaged without any exogenous dye. To integrate a multidimensional scale with a large field of view (non-sliced samples), we have adapted and validated an instrumental coupling between a two photon excitation laser and a macroscope to collect cartography of SHG signal. We introduced an index (F-SHG) based on decay time response measured by TCSPC for respectively Fluorescence (F) and Second Harmonic Generation (SHG) values. For various sample where protein collagen is the major component of extracellular matrix (vessel, skin, carotide vessel, rat femoral head cartilage, mouse tumor, human wharton’s jelly and rat tendon) or not (nacre), we compared the index distribution obtained with MacroSHG. In this work, we showed for the first time that multiscale large field imaging (Macroscopy) combined to Multimodality approaches (SHG-TCSPC) could be an innovative and non-invasive technique to detect and identify some biological interest molecules (collagen) in biomedical topics.展开更多
1 Introduction Obstructive atherosclerosis vascular disease remains one of the greatest public health threats in the world.Sur2 gical treatment to replace diseased blood vessels is usually done using major human allog...1 Introduction Obstructive atherosclerosis vascular disease remains one of the greatest public health threats in the world.Sur2 gical treatment to replace diseased blood vessels is usually done using major human allografts(veins or arteries)or synthetic prosthesis(PTFE,Dacron).However,these substitutes have not a good patency,because of the lack of endothelial cell s(ECs)layer,which prevent s thrombus formation.The challenge of tissue engineering vessel s i s to build2up blood/substitute interface near native vessels.In order to improve ECs adhesion,it is necessary to pre2 coat the intra2luminal vessel.Recently,a new surface modification technique arose,based on the alternate ad2 sorption of oppositely charged polyelectrolytes.Our objec2 tive was to favour the endothelialization of the cryo2pre2 served allografts,treated with a thin polyelectrolyte multi2 layered film,made of PSS(poly(sodium242styrenesul2 fonate))or PAH(poly(allylamine hydrochloride)).展开更多
1 Introduction A method in vascular tissue engineering to obtain hemocompatible synthetic prosthesis consist s to cover the luminal surface by a monolayer of endothelial cell s(ECs).Nevertheless,the surface of current...1 Introduction A method in vascular tissue engineering to obtain hemocompatible synthetic prosthesis consist s to cover the luminal surface by a monolayer of endothelial cell s(ECs).Nevertheless,the surface of current prosthesi s does not favour the development of an ECs monolayer.Recently,a new versatile method of self2assembled archi2 tectures based on the alternate adsorption of polycations and polyanions has been developed to lead to the build2up of multilayered polyelectrolyte films(MPF).This new type of surface modification offers also large possibilities for varying the physico2chemical properties such as rough2 ness or surface charges,film thickness and viscoelastic properties.展开更多
Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrF...Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrFE））, a piezoelectric polymer, is widely used in biomaterial applications. We hypothesized that incorporation of zinc oxide （ZnO） nanoparticles into the P（VDF-TrFE） matrix could promote adhesion, migration, and proliferation of cells, as well as blood vessel formation （angiogenesis）. In this study, we fabricated and comprehensively characterized a novel electrospun P（VDF-TrFE）/ZnO nanocomposite tissue engineering scaffold. We analyzed the morphological features of the polymeric matrix by scanning electron microscopy, and utilized Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to examine changes in the crystalline phases of the copolymer due to addition of the nanoparticles. We detected no or minimal adverse effects of the biomaterials with regard to blood compatibility in vitro, biocompatibility, and cytotoxicity, indicating that P（VDF-TrFE）/ZnO nanocomposite scaffolds are suitable for tissue engineering applications. Interestingly, human mesenchymal stem cells （hMSCs） and human umbilical vein endothelial cells cultured on the nanocomposite scaffolds exhibited higher cell viability, adhesion, and proliferation compared to cells cultured on tissue culture plates or neat P（VDF-TrFE） scaffolds. Nanocomposite scaffolds implanted into rats with or without hMSCs did not elicit immunological responses, as assessed by macroscopic analysis and histology. Importantly, nanocomposite scaffolds promoted angiogenesis, which was increased in scaffolds pre-seeded with hMSCs. Overall, our results highlight the potential of these novel P（VDF-TrFE）/ZnO nanocomposites for use in tissue engineering, due to their biocompatibility and ability to promote cell adhesion and angiogenesis.展开更多
文摘In this work, we have considered a new multimodality imaging for macroscopy based on Second Harmonic Generation (SHG) method to monitor invasivelessly the matrix collagen. As the triple helicoidally structure of collagen molecules appearing as not centrosymetric, very organized and spatially oriented, collagen fibrils give rise to a very strong SHG signal and can be imaged without any exogenous dye. To integrate a multidimensional scale with a large field of view (non-sliced samples), we have adapted and validated an instrumental coupling between a two photon excitation laser and a macroscope to collect cartography of SHG signal. We introduced an index (F-SHG) based on decay time response measured by TCSPC for respectively Fluorescence (F) and Second Harmonic Generation (SHG) values. For various sample where protein collagen is the major component of extracellular matrix (vessel, skin, carotide vessel, rat femoral head cartilage, mouse tumor, human wharton’s jelly and rat tendon) or not (nacre), we compared the index distribution obtained with MacroSHG. In this work, we showed for the first time that multiscale large field imaging (Macroscopy) combined to Multimodality approaches (SHG-TCSPC) could be an innovative and non-invasive technique to detect and identify some biological interest molecules (collagen) in biomedical topics.
文摘1 Introduction Obstructive atherosclerosis vascular disease remains one of the greatest public health threats in the world.Sur2 gical treatment to replace diseased blood vessels is usually done using major human allografts(veins or arteries)or synthetic prosthesis(PTFE,Dacron).However,these substitutes have not a good patency,because of the lack of endothelial cell s(ECs)layer,which prevent s thrombus formation.The challenge of tissue engineering vessel s i s to build2up blood/substitute interface near native vessels.In order to improve ECs adhesion,it is necessary to pre2 coat the intra2luminal vessel.Recently,a new surface modification technique arose,based on the alternate ad2 sorption of oppositely charged polyelectrolytes.Our objec2 tive was to favour the endothelialization of the cryo2pre2 served allografts,treated with a thin polyelectrolyte multi2 layered film,made of PSS(poly(sodium242styrenesul2 fonate))or PAH(poly(allylamine hydrochloride)).
文摘1 Introduction A method in vascular tissue engineering to obtain hemocompatible synthetic prosthesis consist s to cover the luminal surface by a monolayer of endothelial cell s(ECs).Nevertheless,the surface of current prosthesi s does not favour the development of an ECs monolayer.Recently,a new versatile method of self2assembled archi2 tectures based on the alternate adsorption of polycations and polyanions has been developed to lead to the build2up of multilayered polyelectrolyte films(MPF).This new type of surface modification offers also large possibilities for varying the physico2chemical properties such as rough2 ness or surface charges,film thickness and viscoelastic properties.
文摘Piezoelectric materials that generate electrical signals in response to mechanical strain can be used in tissue engineering to stimulate cell proliferation. Poly （vinylidene fluoride-trifluoroethylene） （P（VDF-TrFE））, a piezoelectric polymer, is widely used in biomaterial applications. We hypothesized that incorporation of zinc oxide （ZnO） nanoparticles into the P（VDF-TrFE） matrix could promote adhesion, migration, and proliferation of cells, as well as blood vessel formation （angiogenesis）. In this study, we fabricated and comprehensively characterized a novel electrospun P（VDF-TrFE）/ZnO nanocomposite tissue engineering scaffold. We analyzed the morphological features of the polymeric matrix by scanning electron microscopy, and utilized Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to examine changes in the crystalline phases of the copolymer due to addition of the nanoparticles. We detected no or minimal adverse effects of the biomaterials with regard to blood compatibility in vitro, biocompatibility, and cytotoxicity, indicating that P（VDF-TrFE）/ZnO nanocomposite scaffolds are suitable for tissue engineering applications. Interestingly, human mesenchymal stem cells （hMSCs） and human umbilical vein endothelial cells cultured on the nanocomposite scaffolds exhibited higher cell viability, adhesion, and proliferation compared to cells cultured on tissue culture plates or neat P（VDF-TrFE） scaffolds. Nanocomposite scaffolds implanted into rats with or without hMSCs did not elicit immunological responses, as assessed by macroscopic analysis and histology. Importantly, nanocomposite scaffolds promoted angiogenesis, which was increased in scaffolds pre-seeded with hMSCs. Overall, our results highlight the potential of these novel P（VDF-TrFE）/ZnO nanocomposites for use in tissue engineering, due to their biocompatibility and ability to promote cell adhesion and angiogenesis.
