Tissue engineering is rapidly progressing toward clinical application.In the musculoskeletal field,there has been an increasing necessity for bone and cartilage replacement.Despite the promising translational potentia...Tissue engineering is rapidly progressing toward clinical application.In the musculoskeletal field,there has been an increasing necessity for bone and cartilage replacement.Despite the promising translational potential of tissue engineering approaches,careful attention should be given to the quality of developed constructs to increase the real applicability to patients.After a general introduction to musculoskeletal tissue engineering,this narrative review aims to offer an overview of methods,starting from classical techniques,such as gene expression analysis and histology,to less common methods,such as Raman spectroscopy,microcomputed tomography,and biosensors,that can be employed to assess the quality of constructs in terms of viability,morphology,or matrix deposition.A particular emphasis is given to standards and good practices(GXP),which can be applicable in different sectors.Moreover,a classification of the methods into destructive,noninvasive,or conservative based on the possible further development of a preimplant quality monitoring system is proposed.Biosensors in musculoskeletal tissue engineering have not yet been used but have been proposed as a novel technology that can be exploited with numerous advantages,including minimal invasiveness,making them suitable for the development of preimplant quality control systems.展开更多
Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between...Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with SLG.Na diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs.Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 pm.We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing.The diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 lines.Na-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na diffusion.Our results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.展开更多
Beyond traditional rooftop and building-integrated photovoltaics(BIPV),photovoltaic(PV)devices find applications in agrivoltaics,space,and indoor settings.However,the underwater(UW)environment remains largely unexplor...Beyond traditional rooftop and building-integrated photovoltaics(BIPV),photovoltaic(PV)devices find applications in agrivoltaics,space,and indoor settings.However,the underwater(UW)environment remains largely unexplored.Below 50 m,the solar spectrum shifts dramatically,with only blue-green light(400–600 nm)available.Perovskite solar cells(PSCs),known for their high-power conversion efficiencies(PCEs)and tunable bandgaps,offer potential for this environment.Initially,simulations compared the intensity of the solar radiation based on three models,each based on a different water body,down to a depth of 10 m.展开更多
The current research is devoted to the study of the modification of the titanium implants by the micro-arc oxidation with bioactive calcium phosphate coatings containing Ag or Sr and Si elements.The coatings’microstr...The current research is devoted to the study of the modification of the titanium implants by the micro-arc oxidation with bioactive calcium phosphate coatings containing Ag or Sr and Si elements.The coatings’microstructure,phase composition,morphology,physicochemical and biological properties were examined by scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy(EDX)and X-ray diffraction(XRD).Ag-containing and Sr-Si-incorporated coatings were formed in alkaline and acid electrolytes,respectively.The formation of the coatings occurred at different ranges of the applied voltages,which led to the significant difference in the coatings properties.The trace elements Ag,Sr and Si participated intensively in the plasma-chemical reactions of the micro-arc coatings formation.Ag-containing coatings demonstrated strong antibacterial effect against Staphylococcus aureus AТСС6538-P.MTT in vitro test with 3T3-L1 fibroblasts showed no cytotoxicity appearance on Sr-Si-incorporated coatings.展开更多
The biocompatibility of biphasicα,β-tricalcium phosphate ceramics,obtained by annealing a compact preform based onβ-tricalcium phosphate powder,was studied in vitro.It was found that within 10–30 days the adhesion...The biocompatibility of biphasicα,β-tricalcium phosphate ceramics,obtained by annealing a compact preform based onβ-tricalcium phosphate powder,was studied in vitro.It was found that within 10–30 days the adhesion of primary dental pulp stem cells located on the surface of biphasicα,β-tricalcium phosphate ceramics is suppressed.Decrease of the cell number on the surface of biphasicα,β-tricalcium phosphate ceramics,most likely,can be associated with both the pH level(acidic)as a result of hydrolysis of the more soluble phase ofα-tricalcium phosphate and with the nature of surface that changes as a result of the formation and growth of hydroxyapatite crystals.展开更多
Thanks to their biocompatibility,biodegradability,injectability and self-setting properties,calcium phosphate cements(CPCs)have been the most economical and effective biomaterials of choice for use as bone void filler...Thanks to their biocompatibility,biodegradability,injectability and self-setting properties,calcium phosphate cements(CPCs)have been the most economical and effective biomaterials of choice for use as bone void fillers.They have also been extensively used as drug delivery carriers owing to their ability to provide for a steady release of various organic molecules aiding the regeneration of defective bone,including primarily antibiotics and growth factors.This review provides a systematic compilation of studies that reported on the controlled release of drugs from CPCs in the last 25 years.The chemical,compositional and microstructural characteristics of these systems through which the control of the release rates and mechanisms could be achieved have been discussed.In doing so,the effects of(i)the chemistry of the matrix,(ii)porosity,(iii)additives,(iv)drug types,(v)drug concentrations,(vi)drug loading methods and(vii)release media have been distinguished and discussed individually.Kinetic specificities of in vivo release of drugs from CPCs have been reviewed,too.Understanding the kinetic and mechanistic correlations between the CPC properties and the drug release is a prerequisite for the design of bone void fillers with drug release profiles precisely tailored to the application area and the clinical picture.The goal of this review has been to shed light on these fundamental correlations.展开更多
New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues.Taking inspiration from basic composi...New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues.Taking inspiration from basic composition of the mammalian bones,composed of collagen,apatite and a number of substitution ions,among them magnesium(Mg2+),in this work,novel composite scaffolds composed of collagen(10%)-hydroxyapatite(HAp)(90%)and collagen(10%)-HAp(80%)-Mg(10%)were developed.The lyophilization was used for composites preparation.An insight into the nanostructural nature of the developed scaffolds was performed by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray and Transmission Electron Microscopy coupled with Energy Dispersive X-Ray.The HAp nanocrystallite clusters and Mg nanoparticles were homogeneously distributed within the scaffolds and adherent to the collagen fibrils.The samples were tested for degradation in Simulated Body Fluid(SBF)solution by soaking for up to 28 days.The release of Mg from collagen(10%)-HAp(80%)-Mg(10%)composite during the period of up to 21 days was attested,this composite being characterized by a decreased degradation rate with respect to the composite without Mg.The developed composite materials are promising for applications as bone substitute materials favouring bone healing and regeneration.展开更多
Bioactive calcium phosphate coatings were deposited by radio-frequency magnetron sputtering from biphasic targets of hydroxyapatite and tricalcium phosphate,sintered at different mass%ratios.According to Raman scatter...Bioactive calcium phosphate coatings were deposited by radio-frequency magnetron sputtering from biphasic targets of hydroxyapatite and tricalcium phosphate,sintered at different mass%ratios.According to Raman scattering and X-ray diffraction data,the deposited hydroxyapatite coatings have a disordered structure.High-temperature treatment of the coatings in air leads to a transformation of the quasi-amorphous structure into a crystalline one.A correlation has been observed between the increase in the Ca content in the coatings and a subsequent decrease in Ca in the biphasic targets after a series of deposition processes.It was proposed that the addition of tricalcium phosphate to the targets would led to a finer coating's surface topography with the average size of 78 nm for the structural elements.展开更多
A technique for colloidal forming of Ca2P2O7 macroporous bioceramics,based on low-pressure injection molding(LPIM)of a glycerol-water slip containing Ca2P2O7 and Ca(Н2PO4)2 into a plastic mold fabricated via FDM 3Dpr...A technique for colloidal forming of Ca2P2O7 macroporous bioceramics,based on low-pressure injection molding(LPIM)of a glycerol-water slip containing Ca2P2O7 and Ca(Н2PO4)2 into a plastic mold fabricated via FDM 3Dprinting,was proposed.Chemical reaction between the solid phases of the water containing slip-Ca2P2O7 and Ca(Н2PO4)2,resulting in brushite(CaHPO4·2H2O)formation,led to consolidation of the casting and preserved its complex architecture in the course of mold burning-out.Macroporous ceramics of Kelvin structure(70%macropores with the sizes from 2 up to 4 mm),based on a pre-defined composition with 10 wt%Ca(PO3)2 and sintered in liquid-phase regime,demonstrated a compressive strength of 1.4±0.1 MPa at a density of 22±2%.In vitro tests on bioactivity in SBF solution,as well as on resorption of the ceramics in model solution of citric acid,were carried out.展开更多
Recently,zinc and its alloys have been proposed as promising candidates for biodegradable metals(BMs),owning to their preferable corrosion behavior and acceptable biocompatibility in cardiovascular,bone and gastrointe...Recently,zinc and its alloys have been proposed as promising candidates for biodegradable metals(BMs),owning to their preferable corrosion behavior and acceptable biocompatibility in cardiovascular,bone and gastrointestinal environments,together with Mg-based and Fe-based BMs.However,there is the desire for surface treatment for Zn-based BMs to better control their biodegradation behavior.Firstly,the implantation of some Zn-based BMs in cardiovascular environment exhibited intimal activation with mild inflammation.Secondly,for orthopedic applications,the biodegradation rates of Zn-based BMs are relatively slow,resulting in a long-term retention after fulfilling their mission.Meanwhile,excessive Zn2+release during degradation will cause in vitro cytotoxicity and in vivo delayed osseointegration.In this review,we firstly summarized the current surface modification methods of Zn-based alloys for the industrial applications.Then we comprehensively summarized the recent progress of biomedical bulk Zn-based BMs as well as the corresponding surface modification strategies.Last but not least,the future perspectives towards the design of surface bio-functionalized coatings on Zn-based BMs for orthopedic and cardiovascular applications were also briefly proposed.展开更多
Graphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifica...Graphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifications. These are not limited to the conventional armchair, zigzag, and cove edges, but also possible through incorporation of non-hexagonal rings. On-surface synthesis enables the fabrication and visualization of GNRs with atomically precise chemical structures, but strategies for the incorporation of non-hexagonal rings have been underexplored. Herein, we describe the on-surface synthesis of armchair-edged GNRs with incorporated five-membered rings through the C-H activation and cyclization of benzylic methyl groups. Ortho-Tolyl-substituted dibromobianthryl was employed as the precursor monomer, and visualization of the resulting structures after annealing at 300 °C on a gold surface by high-resolution noncontact atomic force microscopy clearly revealed the formation of methylene-bridged pentagons at the GNR edges. These persisted after annealing at 340 °C, along with a few fully conjugated pentagons having singly-hydrogenated apexes. The benzylic methyl groups could also migrate or cleave-off, resulting in defects lacking the five-membered rings. Moreover, unexpected and unique structural rearrangements, including the formation of embedded heptagons, were observed. Despite the coexistence of different reaction pathways that hamper selective synthesis of a uniform structure, our results provide novel insights into on-surface reactions en route to functional, non-benzenoid carbon nanomaterials.展开更多
This special issue is dedicated to the selected papers of the 1st biennial International Conference BioMaH-BioMaterials for Healthcare“Biomaterials for Tissue and Genetic Engineering and the Role of Nanotechnology”h...This special issue is dedicated to the selected papers of the 1st biennial International Conference BioMaH-BioMaterials for Healthcare“Biomaterials for Tissue and Genetic Engineering and the Role of Nanotechnology”held in Rome(Italy)in October 17-20,2016.The special issue is focused on the new frontiers of bioactive materials facing challenges and embracing opportunities in the field of tissue regeneration and repair.The focus includes a wide range of chemical,physical,and biological aspects,with the scope of exploring emerging technologies for a large variety of engineered materials,their combinations,and interfaces with specific biofunctionality.展开更多
On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited ...On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited success.Herein,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended ZGNRs.Characterization by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused ZGNRs.Unique skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder cycloaddition.Theoretical calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.展开更多
Orthopedic infections pose severe societal and economic burden and interfere with the capability of the implanted devices to integrate in the host bone,thus significantly increasing implants failure rate.To address in...Orthopedic infections pose severe societal and economic burden and interfere with the capability of the implanted devices to integrate in the host bone,thus significantly increasing implants failure rate.To address infection and promote integration,here nanostructured antibacterial and bioactive thin films are proposed,obtained,for the first time,by Ionized Jet Deposition(IJD)of silver-substituted tricalcium phosphate(Ag-TCP)targets on titanium.Coatings morphology,composition and mechanical properties are characterized and proof-of-concept of biocompatibility is shown.Antimicrobial efficacy is investigated against four Gram positive and Gram negative bacterial strains and against C.albicans fungus,by investigating the modifications in planktonic bacterial growth in the absence and presence of silver.Then,for all bacterial strains,the capability of the film to inhibit bacterial adhesion is also tested.Results indicate that IJD permits a fine control over films composition and morphology and deposition of films with suitable mechanical properties.Biological studies show a good efficacy against Escherichia coli,Staphylococcus aureus,Pseudomonas aeruginosa,Enterococcus faecalis and against fungus Candida albicans,with evidences of efficacy against planktonic growth and significant reduction of bacterial cell adhesion.No cytotoxic effects are evidenced for equine adipose tissue derived mesenchymal stem cells(ADMSCs),as no reductions are caused to cells viability and no interference is assessed in cells differentiation towards osteogenic lineage,in the presence of silver.Instead,thanks to nanostructuration and biomimetic composition,tricalcium phosphate(TCP)coatings favor cells viability,also when silver-substituted.These findings show that silver-substituted nanostructured coatings are promising for orthopedic implant applications.展开更多
On-surface synthesis is a rapidly developing field involving chemical reactions on well-defined solid surfaces toaccess synthesis of low-dimensional organic nanostructures which cannot be achieved via traditional solu...On-surface synthesis is a rapidly developing field involving chemical reactions on well-defined solid surfaces toaccess synthesis of low-dimensional organic nanostructures which cannot be achieved via traditional solutionchemistry. On-surface reactions critically depend on a high degree of chemoselectivity in order to achieve anoptimum balance between target structure and possible side products. Here, we demonstrate synthesis of graphenenanoribbons with a large unit cell based on steric hindrance-induced complete chemoselectivity as revealed byscanning probe microscopy measurements and density functional theory calculations. Our results disclose thatcombined molecule-substrate van der Waals interactions and intermolecular steric hindrance promote a selectivearyl-aryl coupling, giving rise to high-quality uniform graphene nanostructures. The established coupling strategyhas been used to synthesize two types of graphene nanoribbons with different edge topologies inducing apronounced variation of the electronic energy gaps. The demonstrated chemoselectivity is representative forn-anthryl precursor molecules and may be further exploited to synthesize graphene nanoribbons with novelelectronic, topological and magnetic properties with implications for electronic and spintronic applications.展开更多
文摘Tissue engineering is rapidly progressing toward clinical application.In the musculoskeletal field,there has been an increasing necessity for bone and cartilage replacement.Despite the promising translational potential of tissue engineering approaches,careful attention should be given to the quality of developed constructs to increase the real applicability to patients.After a general introduction to musculoskeletal tissue engineering,this narrative review aims to offer an overview of methods,starting from classical techniques,such as gene expression analysis and histology,to less common methods,such as Raman spectroscopy,microcomputed tomography,and biosensors,that can be employed to assess the quality of constructs in terms of viability,morphology,or matrix deposition.A particular emphasis is given to standards and good practices(GXP),which can be applicable in different sectors.Moreover,a classification of the methods into destructive,noninvasive,or conservative based on the possible further development of a preimplant quality monitoring system is proposed.Biosensors in musculoskeletal tissue engineering have not yet been used but have been proposed as a novel technology that can be exploited with numerous advantages,including minimal invasiveness,making them suitable for the development of preimplant quality control systems.
基金the Jardine Foundation and Cambridge Trust for a doctoral scholarshipthe European Union(EU)Horizon 2020 research and innovation program under grant No.764047(ESPResSo)+12 种基金funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No.823717-ESTEEM3.J.F.Oacknowledges funding from the Engineering and Physical Sciences Research Council(EPSRC)Nano Doctoral Training Centre(EP/L015978/1)J.F.O.,G.K.,and R.A.O.acknowledge Attolight and EPSRC(EP/R025193/1)for funding and supporting the SEM-CL systemE.M.T.thanks the EU Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no.841265.S.D.S.E.M.T.acknowledge funding from the EPSRC(EP/R023980/1)the EPSRC Centre for Advanced Materials for Integrated Energy Systems(CAM-IES,EP/P007767/1)Cambridge Royce facilities grant(EP/P024947/1)S.D.S.acknowledges funding from the Royal Society and Tata Group(UF150033)from the European Research Council under the EU Horizon 2020 research and innovation program under grant No.756962(HYPERION)W.L.and J.L.M.-D.acknowledge support from the EPSRC(EP/L011700/1,EP/N004272/1)the Leverhulme Trust(RPG-2015-017)the Royal Academy of Engineering Chair in Emerging Technologies(CiET1819_24)We wish to acknowledge the support of the Henry Royce Institute(HRI)for F.U.K.through the Royce PhD Equipment Access Scheme enabling access to the NanoSIMS facility at Manchester.The NanoSIMS was funded by UK Research Partnership Investment Funding(UKRPIF)Manchester RPIF Round 2.This work was supported by the HRI,funded through EPSRC grants EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1
文摘Most thin-film photovoltaic modules are constructed on soda-lime glass(SLG)substrates containing alkali oxides,such as Na_(2)O.Na may diffuse from SLG into a module's active layers through P1 lines,an area between a module's constituent cells where the substrate-side charge transport layer(CTL)is in direct contact with SLG.Na diffusion from SLG is known to cause several important effects inⅡ-Ⅵand chalcogenide solar modules,but it has not been studied in perovskite solar modules(PSMs).In this work,we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs.Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 pm.We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing.The diffused Na preferentially binds with Br,forming Br-poor,l-rich perovskite and a species rich in Na and Br(Na-Br)close to P1 lines.Na-Br passivates defect sites,reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5×.Na-Br is observed to be stable after 12 weeks of device storage,suggesting long-lasting effects of Na diffusion.Our results not only point to a potential avenue to increase PSM performance but also highlight the possibility of unabated Na diffusion throughout a module's lifetime,especially if accelerated by the electric field and elevated temperatures achievable during device operation.
基金the support of the Project“Network 4 Energy Sustainable Transition─NEST”,Spoke 1,Project code PE0000021funded under the National Recovery and Resilience Plan(NRRP),Mission 4,Component 2,Investment 1.3-Cal for tender No.1561 of 11.10.2022 of Ministero del’Universita e del a Ricerca(MUR)funded by the European Union-Next Generation EU。
文摘Beyond traditional rooftop and building-integrated photovoltaics(BIPV),photovoltaic(PV)devices find applications in agrivoltaics,space,and indoor settings.However,the underwater(UW)environment remains largely unexplored.Below 50 m,the solar spectrum shifts dramatically,with only blue-green light(400–600 nm)available.Perovskite solar cells(PSCs),known for their high-power conversion efficiencies(PCEs)and tunable bandgaps,offer potential for this environment.Initially,simulations compared the intensity of the solar radiation based on three models,each based on a different water body,down to a depth of 10 m.
基金supported by the Fundamental Research Program of the State Academies of Sciences for 2013-2020,direction of research Ⅲ.23.2.
文摘The current research is devoted to the study of the modification of the titanium implants by the micro-arc oxidation with bioactive calcium phosphate coatings containing Ag or Sr and Si elements.The coatings’microstructure,phase composition,morphology,physicochemical and biological properties were examined by scanning electron microscopy(SEM),transmission electron microscopy(TEM),energy-dispersive X-ray spectroscopy(EDX)and X-ray diffraction(XRD).Ag-containing and Sr-Si-incorporated coatings were formed in alkaline and acid electrolytes,respectively.The formation of the coatings occurred at different ranges of the applied voltages,which led to the significant difference in the coatings properties.The trace elements Ag,Sr and Si participated intensively in the plasma-chemical reactions of the micro-arc coatings formation.Ag-containing coatings demonstrated strong antibacterial effect against Staphylococcus aureus AТСС6538-P.MTT in vitro test with 3T3-L1 fibroblasts showed no cytotoxicity appearance on Sr-Si-incorporated coatings.
文摘The biocompatibility of biphasicα,β-tricalcium phosphate ceramics,obtained by annealing a compact preform based onβ-tricalcium phosphate powder,was studied in vitro.It was found that within 10–30 days the adhesion of primary dental pulp stem cells located on the surface of biphasicα,β-tricalcium phosphate ceramics is suppressed.Decrease of the cell number on the surface of biphasicα,β-tricalcium phosphate ceramics,most likely,can be associated with both the pH level(acidic)as a result of hydrolysis of the more soluble phase ofα-tricalcium phosphate and with the nature of surface that changes as a result of the formation and growth of hydroxyapatite crystals.
文摘Thanks to their biocompatibility,biodegradability,injectability and self-setting properties,calcium phosphate cements(CPCs)have been the most economical and effective biomaterials of choice for use as bone void fillers.They have also been extensively used as drug delivery carriers owing to their ability to provide for a steady release of various organic molecules aiding the regeneration of defective bone,including primarily antibiotics and growth factors.This review provides a systematic compilation of studies that reported on the controlled release of drugs from CPCs in the last 25 years.The chemical,compositional and microstructural characteristics of these systems through which the control of the release rates and mechanisms could be achieved have been discussed.In doing so,the effects of(i)the chemistry of the matrix,(ii)porosity,(iii)additives,(iv)drug types,(v)drug concentrations,(vi)drug loading methods and(vii)release media have been distinguished and discussed individually.Kinetic specificities of in vivo release of drugs from CPCs have been reviewed,too.Understanding the kinetic and mechanistic correlations between the CPC properties and the drug release is a prerequisite for the design of bone void fillers with drug release profiles precisely tailored to the application area and the clinical picture.The goal of this review has been to shed light on these fundamental correlations.
基金This work was funded by a grant of the Romanian Ministry of Research and Innovation,CCCDI-UEFISCDI,Project COFUND-M-ERA.NET Ⅱ-BiogenInk/70/2017,within PNCDI Ⅲ.
文摘New materials are required for bone healing in regenerative medicine able to temporarily substitute damaged bone and to be subsequently resorbed and replaced by endogenous tissues.Taking inspiration from basic composition of the mammalian bones,composed of collagen,apatite and a number of substitution ions,among them magnesium(Mg2+),in this work,novel composite scaffolds composed of collagen(10%)-hydroxyapatite(HAp)(90%)and collagen(10%)-HAp(80%)-Mg(10%)were developed.The lyophilization was used for composites preparation.An insight into the nanostructural nature of the developed scaffolds was performed by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray and Transmission Electron Microscopy coupled with Energy Dispersive X-Ray.The HAp nanocrystallite clusters and Mg nanoparticles were homogeneously distributed within the scaffolds and adherent to the collagen fibrils.The samples were tested for degradation in Simulated Body Fluid(SBF)solution by soaking for up to 28 days.The release of Mg from collagen(10%)-HAp(80%)-Mg(10%)composite during the period of up to 21 days was attested,this composite being characterized by a decreased degradation rate with respect to the composite without Mg.The developed composite materials are promising for applications as bone substitute materials favouring bone healing and regeneration.
基金The study was conducted as part of the program of fundamental research of the state academies of sciences(PFR SAS)for 2015e2017 No.23.2.5The project was supported by Marie Curie IRSES,project No.612691 of the EU Framework Programme-FP7The authors thank A.Sainova,Yu.Glushko,M.Surmeneva,and Prof.M.Chaikina for support to the research and fruitful discussion of the results.
文摘Bioactive calcium phosphate coatings were deposited by radio-frequency magnetron sputtering from biphasic targets of hydroxyapatite and tricalcium phosphate,sintered at different mass%ratios.According to Raman scattering and X-ray diffraction data,the deposited hydroxyapatite coatings have a disordered structure.High-temperature treatment of the coatings in air leads to a transformation of the quasi-amorphous structure into a crystalline one.A correlation has been observed between the increase in the Ca content in the coatings and a subsequent decrease in Ca in the biphasic targets after a series of deposition processes.It was proposed that the addition of tricalcium phosphate to the targets would led to a finer coating's surface topography with the average size of 78 nm for the structural elements.
基金supported by the RFBR(grants No.18-33-00789 mol_a,18-08-01473,19-03-00940)。
文摘A technique for colloidal forming of Ca2P2O7 macroporous bioceramics,based on low-pressure injection molding(LPIM)of a glycerol-water slip containing Ca2P2O7 and Ca(Н2PO4)2 into a plastic mold fabricated via FDM 3Dprinting,was proposed.Chemical reaction between the solid phases of the water containing slip-Ca2P2O7 and Ca(Н2PO4)2,resulting in brushite(CaHPO4·2H2O)formation,led to consolidation of the casting and preserved its complex architecture in the course of mold burning-out.Macroporous ceramics of Kelvin structure(70%macropores with the sizes from 2 up to 4 mm),based on a pre-defined composition with 10 wt%Ca(PO3)2 and sintered in liquid-phase regime,demonstrated a compressive strength of 1.4±0.1 MPa at a density of 22±2%.In vitro tests on bioactivity in SBF solution,as well as on resorption of the ceramics in model solution of citric acid,were carried out.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51931001,51901003)the International Cooperation and Exchange project between NSFC(China)and CNR(Italy)(NSFC-CNR Grant No.52011530392)the Open Project of NMPA Key Laboratory for Dental Materials(Grant No.PKUSS20200401).
文摘Recently,zinc and its alloys have been proposed as promising candidates for biodegradable metals(BMs),owning to their preferable corrosion behavior and acceptable biocompatibility in cardiovascular,bone and gastrointestinal environments,together with Mg-based and Fe-based BMs.However,there is the desire for surface treatment for Zn-based BMs to better control their biodegradation behavior.Firstly,the implantation of some Zn-based BMs in cardiovascular environment exhibited intimal activation with mild inflammation.Secondly,for orthopedic applications,the biodegradation rates of Zn-based BMs are relatively slow,resulting in a long-term retention after fulfilling their mission.Meanwhile,excessive Zn2+release during degradation will cause in vitro cytotoxicity and in vivo delayed osseointegration.In this review,we firstly summarized the current surface modification methods of Zn-based alloys for the industrial applications.Then we comprehensively summarized the recent progress of biomedical bulk Zn-based BMs as well as the corresponding surface modification strategies.Last but not least,the future perspectives towards the design of surface bio-functionalized coatings on Zn-based BMs for orthopedic and cardiovascular applications were also briefly proposed.
基金We are grateful for the financial support by the Max Planck Society,the Swiss National Science Foundation under Grant No.200020_182015the NCCR MARVEL funded by the Swiss National Science Foundation(No.51NF40-182892)+3 种基金the European Union’s Horizon 2020 research and innovation programme under grant agreement number 785219(Graphene Flagship Core 2)the Office of Naval Research(No.N00014-18-1-2708)the Okinawa Institute of Science and Technology Graduate University(OIST)The Swiss National Supercomputing Centre(CSCS)under project ID s904 is acknowledged for computational resources.
文摘Graphene nanoribbons (GNRs) have potential for applications in electronic devices. A key issue, thereby, is the fine-tuning of their electronic characteristics, which can be achieved through subtle structural modifications. These are not limited to the conventional armchair, zigzag, and cove edges, but also possible through incorporation of non-hexagonal rings. On-surface synthesis enables the fabrication and visualization of GNRs with atomically precise chemical structures, but strategies for the incorporation of non-hexagonal rings have been underexplored. Herein, we describe the on-surface synthesis of armchair-edged GNRs with incorporated five-membered rings through the C-H activation and cyclization of benzylic methyl groups. Ortho-Tolyl-substituted dibromobianthryl was employed as the precursor monomer, and visualization of the resulting structures after annealing at 300 °C on a gold surface by high-resolution noncontact atomic force microscopy clearly revealed the formation of methylene-bridged pentagons at the GNR edges. These persisted after annealing at 340 °C, along with a few fully conjugated pentagons having singly-hydrogenated apexes. The benzylic methyl groups could also migrate or cleave-off, resulting in defects lacking the five-membered rings. Moreover, unexpected and unique structural rearrangements, including the formation of embedded heptagons, were observed. Despite the coexistence of different reaction pathways that hamper selective synthesis of a uniform structure, our results provide novel insights into on-surface reactions en route to functional, non-benzenoid carbon nanomaterials.
文摘This special issue is dedicated to the selected papers of the 1st biennial International Conference BioMaH-BioMaterials for Healthcare“Biomaterials for Tissue and Genetic Engineering and the Role of Nanotechnology”held in Rome(Italy)in October 17-20,2016.The special issue is focused on the new frontiers of bioactive materials facing challenges and embracing opportunities in the field of tissue regeneration and repair.The focus includes a wide range of chemical,physical,and biological aspects,with the scope of exploring emerging technologies for a large variety of engineered materials,their combinations,and interfaces with specific biofunctionality.
基金This work was supported by the Swiss National Science Foundation(Grant No.200020_212875)the NCCR MAR-VEL funded by the Swiss National Science Foundation(Grant No.205602)the Werner Siemens Foundation,the Max Planck Society,and the Okinawa Institute of Science and Technology Graduate University.K.M.acknowledges a fellowship from Gutenberg Research College,Johannes Gutenberg University Mainz.Computational support from the Swiss Supercomputing Center(CSCS)under project ID s1141 is gratefully acknowl-edged.We acknowledge PRACE for awarding access to the Fenix Infrastructure resources at CSCS,which are partially funded by the European Union’s Horizon 2020 research and innovation program through the ICEI project under grant agreement No.800858.Technical support from Lukas Rotach is gratefully acknowledged.
文摘On-surface synthesis has emerged as a powerful strategy to fabricate unprecedented forms of atomically precise graphene nanoribbons(GNRs).However,the on-surface synthesis of zigzag GNRs(ZGNR)has met with only limited success.Herein,we report the synthesis and on-surface reactions of 2,7-dibromo-9,9′-bianthryl as the precursor towardπ-extended ZGNRs.Characterization by scanning tunneling microscopy and high-resolution noncontact atomic force microscopy clearly demonstrated the formation of anthracene-fused ZGNRs.Unique skeletal rearrangements were also observed,which could be explained by intramolecular Diels-Alder cycloaddition.Theoretical calculations of the electronic properties of the anthracene-fused ZGNRs revealed spin-polarized edge-states and a narrow bandgap of 0.20 eV.
基金Dr.Gabriela Graziani acknowledges funding from the project Starting Grant SG-2018-12367059financed by the Italian Ministry of Health(BANDO RICERCA FINALIZZATA 2018).
文摘Orthopedic infections pose severe societal and economic burden and interfere with the capability of the implanted devices to integrate in the host bone,thus significantly increasing implants failure rate.To address infection and promote integration,here nanostructured antibacterial and bioactive thin films are proposed,obtained,for the first time,by Ionized Jet Deposition(IJD)of silver-substituted tricalcium phosphate(Ag-TCP)targets on titanium.Coatings morphology,composition and mechanical properties are characterized and proof-of-concept of biocompatibility is shown.Antimicrobial efficacy is investigated against four Gram positive and Gram negative bacterial strains and against C.albicans fungus,by investigating the modifications in planktonic bacterial growth in the absence and presence of silver.Then,for all bacterial strains,the capability of the film to inhibit bacterial adhesion is also tested.Results indicate that IJD permits a fine control over films composition and morphology and deposition of films with suitable mechanical properties.Biological studies show a good efficacy against Escherichia coli,Staphylococcus aureus,Pseudomonas aeruginosa,Enterococcus faecalis and against fungus Candida albicans,with evidences of efficacy against planktonic growth and significant reduction of bacterial cell adhesion.No cytotoxic effects are evidenced for equine adipose tissue derived mesenchymal stem cells(ADMSCs),as no reductions are caused to cells viability and no interference is assessed in cells differentiation towards osteogenic lineage,in the presence of silver.Instead,thanks to nanostructuration and biomimetic composition,tricalcium phosphate(TCP)coatings favor cells viability,also when silver-substituted.These findings show that silver-substituted nanostructured coatings are promising for orthopedic implant applications.
基金support from the Swiss National Science Foundation under Grant No.200020_182015support by the Max Planck Society.CAP acknowledges the NCCR MARVEL funded by the Swiss National Science Foundation(grant no.51NF40-205602)The Swiss Supercomputing Center(CSCS)is acknowledged for computational resources(project ID s1141).
文摘On-surface synthesis is a rapidly developing field involving chemical reactions on well-defined solid surfaces toaccess synthesis of low-dimensional organic nanostructures which cannot be achieved via traditional solutionchemistry. On-surface reactions critically depend on a high degree of chemoselectivity in order to achieve anoptimum balance between target structure and possible side products. Here, we demonstrate synthesis of graphenenanoribbons with a large unit cell based on steric hindrance-induced complete chemoselectivity as revealed byscanning probe microscopy measurements and density functional theory calculations. Our results disclose thatcombined molecule-substrate van der Waals interactions and intermolecular steric hindrance promote a selectivearyl-aryl coupling, giving rise to high-quality uniform graphene nanostructures. The established coupling strategyhas been used to synthesize two types of graphene nanoribbons with different edge topologies inducing apronounced variation of the electronic energy gaps. The demonstrated chemoselectivity is representative forn-anthryl precursor molecules and may be further exploited to synthesize graphene nanoribbons with novelelectronic, topological and magnetic properties with implications for electronic and spintronic applications.
