In the last decade,the use of magnesium and its alloys as biodegradable implant materials has become increasingly accepted.However,surface modification of these materials to control the degradation rate in the early s...In the last decade,the use of magnesium and its alloys as biodegradable implant materials has become increasingly accepted.However,surface modification of these materials to control the degradation rate in the early stages of healing and improve their biocompatibility is crucial to the successful implementation of magnesium alloy implants in medicine.Cell adhesion and proliferation at the implant surface is a vital factor for successful integration of a biomaterial within the body.Cells accomplish this task by binding to ligands such as the arginine-glycine-aspartic acid peptide sequence(RGD)commonly found on adhesive proteins present in the extracellular matrix.In this paper,we report a biomimetic surface modification strategy involving deposition of a mixed organosilane layer on Mg AZ31 followed by covalent immobilization of RGD peptides through a heterobifunctional cross-linker molecule.Our results indicate that with optimized deposition conditions uniform organosilane coatings were successfully deposited on the Mg AZ31 substrate.Furthermore,we have demonstrated that the surface density of immobilized RGD can be varied by depositing organosilane layers from solutions containing two different organosilanes in specified ratios.Increases in cell adhesion and cell proliferation were observed on the surface modified substrates.展开更多
The integration of implants or medical devices into the body tissues requires of good cell–material interactions.However,most polymeric materials used for these applications lack on biological cues,which enhanced mid...The integration of implants or medical devices into the body tissues requires of good cell–material interactions.However,most polymeric materials used for these applications lack on biological cues,which enhanced mid-and long-term implant failure due to weak integration with the surrounding tissue.Commonly used strategies for tissue–material integration focus on functionalization of the material surface by means of natural proteins or short peptides.However,the use of these biomolecules involves major drawbacks such as immunogenic problems and oversimplification of the constructs.Here,designed elastin-like recombinamers(ELRs)are used to enhance poly(methyl methacrylate)surface properties and compared against the use of short peptides.In this study,cell response has been analysed for different functionalization conditions in the presence and absence of a competing protein,which interferes on surface–cell interaction by unspecific adsorption on the interface.The study has shown that ELRs can induce higher rates of cell attachment and stronger cell anchorages than short peptides,being a better choice for surface functionalization.展开更多
Anisotropic surface topography is known to induce the contact guidance of cells, and facile and biocompatible approaches of the physical modification of the pertinent matrix surfaces are thus meaningful for biomateria...Anisotropic surface topography is known to induce the contact guidance of cells, and facile and biocompatible approaches of the physical modification of the pertinent matrix surfaces are thus meaningful for biomaterials. Herein, we put forward a sugar-fiber imprinting technique to generate microgrooves on hydrophobic polymers demonstrated by the poly（lactic-eo-glycolic acid） （PLGA） films. Microgrooves were conveniently generated after removing sugar fibers simply by water. The resulting locally anisotropic microgrooves were confirmed to elongate the cells cultured on the surface.展开更多
Cell adhesion to extracellular matrices(ECM)is critical to physiological and pathological processes as well as biomedical and biotechnological applications.It has been known that a cell can adhere on an adhesive micro...Cell adhesion to extracellular matrices(ECM)is critical to physiological and pathological processes as well as biomedical and biotechnological applications.It has been known that a cell can adhere on an adhesive microisland only over a critical size.But no publication has concerned critical adhesion areas of cells on microislands with nanoarray decoration.Herein,we fabricated a series of micro-nanopatterns with different microisland sizes and arginine-glycine-aspartate(RGD)nanospacings on a nonfouling poly(ethylene glycol)background.Besides reproducing that nanospacing of RGD,a ligand of its receptor integrin(a membrane protein),significantly influences specific cell adhesion on bioactive nanoarrays,we confirmed that the concept of critical adhesion area originally suggested in studies of cells on micropatterns was justified also on the micro-nanopatterns,yet the latter exhibited more characteristic behaviors of cell adhesion.We found increased critical adhesion areas of human mesenchymal stem cells(hMSCs)on nanoarrayed microislands with increased RGD nanospacings.However,the numbers of nanodots with respect to the critical adhesion areas were not a constant.A unified interpretation was then put forward after combining nonspecific background adhesion and specific cell adhesion.We further carried out the asymptotic analysis of a series of micro-nanopatterned surfaces to obtain the effective RGD nanospacing on unpatterned free surfaces with densely grafted RGD,which could be estimated nonzero but has never been revealed previously without the assistance of the micro-nanopatterning techniques and the corresponding analysis.展开更多
基金The authors gratefully acknowledge the support of the Natural Sciences and Engineering Research Council of Canada(RGPIN/298348-2010)the Laurentian University Research Fund.
文摘In the last decade,the use of magnesium and its alloys as biodegradable implant materials has become increasingly accepted.However,surface modification of these materials to control the degradation rate in the early stages of healing and improve their biocompatibility is crucial to the successful implementation of magnesium alloy implants in medicine.Cell adhesion and proliferation at the implant surface is a vital factor for successful integration of a biomaterial within the body.Cells accomplish this task by binding to ligands such as the arginine-glycine-aspartic acid peptide sequence(RGD)commonly found on adhesive proteins present in the extracellular matrix.In this paper,we report a biomimetic surface modification strategy involving deposition of a mixed organosilane layer on Mg AZ31 followed by covalent immobilization of RGD peptides through a heterobifunctional cross-linker molecule.Our results indicate that with optimized deposition conditions uniform organosilane coatings were successfully deposited on the Mg AZ31 substrate.Furthermore,we have demonstrated that the surface density of immobilized RGD can be varied by depositing organosilane layers from solutions containing two different organosilanes in specified ratios.Increases in cell adhesion and cell proliferation were observed on the surface modified substrates.
基金This work was supported by the Spain’s Ministerio de Economı´a y Competitividad[projects MAT2008-06887-C03-01,MAT2010-15310,MAT2013-41723-R,MAT2013-42473-R,VA313U14 and VA244U13].X.P.acknowledges grant BES-2009-027524 from the Spain’s Ministerio de Economı´a y Competitividad.
文摘The integration of implants or medical devices into the body tissues requires of good cell–material interactions.However,most polymeric materials used for these applications lack on biological cues,which enhanced mid-and long-term implant failure due to weak integration with the surrounding tissue.Commonly used strategies for tissue–material integration focus on functionalization of the material surface by means of natural proteins or short peptides.However,the use of these biomolecules involves major drawbacks such as immunogenic problems and oversimplification of the constructs.Here,designed elastin-like recombinamers(ELRs)are used to enhance poly(methyl methacrylate)surface properties and compared against the use of short peptides.In this study,cell response has been analysed for different functionalization conditions in the presence and absence of a competing protein,which interferes on surface–cell interaction by unspecific adsorption on the interface.The study has shown that ELRs can induce higher rates of cell attachment and stronger cell anchorages than short peptides,being a better choice for surface functionalization.
文摘Anisotropic surface topography is known to induce the contact guidance of cells, and facile and biocompatible approaches of the physical modification of the pertinent matrix surfaces are thus meaningful for biomaterials. Herein, we put forward a sugar-fiber imprinting technique to generate microgrooves on hydrophobic polymers demonstrated by the poly（lactic-eo-glycolic acid） （PLGA） films. Microgrooves were conveniently generated after removing sugar fibers simply by water. The resulting locally anisotropic microgrooves were confirmed to elongate the cells cultured on the surface.
基金supported by the National Key R&D Program of China(No.2016YFC1100300)he National Natural Science Foundation of China(Nos.21961160721 and 21704018).
文摘Cell adhesion to extracellular matrices(ECM)is critical to physiological and pathological processes as well as biomedical and biotechnological applications.It has been known that a cell can adhere on an adhesive microisland only over a critical size.But no publication has concerned critical adhesion areas of cells on microislands with nanoarray decoration.Herein,we fabricated a series of micro-nanopatterns with different microisland sizes and arginine-glycine-aspartate(RGD)nanospacings on a nonfouling poly(ethylene glycol)background.Besides reproducing that nanospacing of RGD,a ligand of its receptor integrin(a membrane protein),significantly influences specific cell adhesion on bioactive nanoarrays,we confirmed that the concept of critical adhesion area originally suggested in studies of cells on micropatterns was justified also on the micro-nanopatterns,yet the latter exhibited more characteristic behaviors of cell adhesion.We found increased critical adhesion areas of human mesenchymal stem cells(hMSCs)on nanoarrayed microislands with increased RGD nanospacings.However,the numbers of nanodots with respect to the critical adhesion areas were not a constant.A unified interpretation was then put forward after combining nonspecific background adhesion and specific cell adhesion.We further carried out the asymptotic analysis of a series of micro-nanopatterned surfaces to obtain the effective RGD nanospacing on unpatterned free surfaces with densely grafted RGD,which could be estimated nonzero but has never been revealed previously without the assistance of the micro-nanopatterning techniques and the corresponding analysis.
