Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma elec...Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma electrolytic oxidation(PEO)method is a simple strategy to deposit an oxide layer on the surface of light metals such as magnesium alloys,to control corrosion rate and promote some other properties,depending on their performances.Nevertheless,their features including their micropore size,distribution,and interconnectivity,and microcracks have not been improved to an acceptable level to support long-term performances of the magnesium-based substrates.Studies have introduced micro/nano-enabled approaches to enhance various properties of PEO coatings such as corrosion resistance,tribological properties,self-healing ability,bioactivity,biocompatibility,antibacterial properties,or catalytic performances.These strategies consist of incorporating of micro and nanoparticles into the PEO layers to produce multi-functional surfaces or the formation of multi-layered coatings to cover the defects of PEO coatings.In this perspective,the present paper aims to overview various nano/micro-enabled strategies to promote the properties of PEO coatings on magnesium alloys.The main focus is given to the functional changes that occurred in response to the incorporation of various types of nano/micro-structures into the PEO coatings on magnesium alloys.展开更多
The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders...The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.展开更多
Cartilage injuries are common problems that increase with the population aging.Cartilage is an avascular tissue with a relatively low level of cellular mitotic activity,which makes it impossible to heal spontaneously....Cartilage injuries are common problems that increase with the population aging.Cartilage is an avascular tissue with a relatively low level of cellular mitotic activity,which makes it impossible to heal spontaneously.To compensate for this problem,three-dimensional bio-printing has attracted a great deal of attention in cartilage tissue engineering.This emerging technology aims to create three-dimensional functional scaffolds by accurately depositing layer-by-layer bio-inks composed of biomaterial and cells.As a novel bio-ink,a decellularized extracellular matrix can serve as an appropriate substrate that contains all the necessary biological cues for cellular interactions.Here,this review is intended to provide an overview of decellularized extracellular matrix-based bio-inks and their properties,sources,and preparation process.Following this,decellularized extracellular matrix-based bio-inks for cartilage tissue engineering are discussed,emphasizing cell behavior and in-vivo applications.Afterward,the current challenges and future outlook will be discussed to determine the conclusing remarks.展开更多
Background:Nowadays,a wide range of wound dressings is already commercially available.The selection of the dressing is of paramount importance as inappropriate wound management and dressing selection can delay the wou...Background:Nowadays,a wide range of wound dressings is already commercially available.The selection of the dressing is of paramount importance as inappropriate wound management and dressing selection can delay the wound healing process.Not only can this be distressing for the patient,but it can also contribute to complications such as maceration and subsequent infection.Many researchers are targeting the design of dressings with superior properties over existing commercial dressings.However,reported results in the state-of-the-art are rarely benchmarked against commercial dressings.The aim of this study was to determine several characteristics of a large variety of the most frequently used commercial wound dressings,providing an overview for both practitioners and researchers.Methods:For this comparative study,11 frequently used commercial wound dressings were selected,representing the different types.The morphology was studied using scanning electron microscopy.The dressings were characterized in terms of swelling capacity(water,phosphate buffered saline and simulated wound fluid),moisture vapour transmission rate(MVTR)and moisture uptake capacity(via dynamic vapour sorption)as well as mechanical properties using tensile testing and texturometry.Results:The selected dressings showed distinctive morphological differences(fibrous,porous and/or gel)which was reflected in the different properties.Indeed,the swelling capacities ranged between 1.5 and 23.2 g/g(water),2.1 and 17.6 g/g(phosphate buffered saline)or 2.9 and 20.8 g/g(simulated wound fluid).The swelling capacity of the dressings in water increased even further upon freeze-drying,due to the formation of pores.The MVTR values varied between 40 and 930 g/m^(2)/24 h.The maximal moisture uptake capacity varied between 5.8%and 105.7%at 95%relative humidity.Some commercial dressings exhibited a superior mechanical strength,due to either being hydrophobic or multi-layered.Conclusions:The present work not only offers insight into a valuable toolbox of suitable wound dressing characterization techniques,but also provides an extensive landscaping of commercial dressings along with their physico-chemical properties,obtained through reproducible experimen-tal protocols.Furthermore,it ensures appropriate benchmark values for commercial dressings in all forthcoming studies and could aid researchers with the development of novel modern wound dressings.The tested dressings either exhibited a high strength or a high swelling capacity,suggesting that there is still a strong potential in the wound dressings market for dressings that possess both.展开更多
The distribution of photo-crosslinkable moieties onto a protein backbone can affect a biomaterial’s crosslinking behavior, and therefore also its mechanical and biological properties. A profound insight in this respe...The distribution of photo-crosslinkable moieties onto a protein backbone can affect a biomaterial’s crosslinking behavior, and therefore also its mechanical and biological properties. A profound insight in this respect is essential for biomaterials exploited in tissue engineering and regenerative medicine. In the present work, photo-crosslinkable moieties have been introduced on the primary amine groups of: (i) a recombinant collagen peptide (RCPhC1) with a known amino acid (AA) sequence, and (ii) bovine skin collagen (COL BS) with an unknown AA sequence. The degree of substitution (DS) was quantified with two conventional techniques: an ortho-phthalic dialdehyde (OPA) assay and ^(1)H NMR spectroscopy. However, neither of both provides information on the exact type and location of the modified AAs. Therefore, for the first time, proteomic analysis was evaluated herein as a tool to identify functionalized AAs as well as the exact position of photo-crosslinkable moieties along the AA sequence, thereby enabling an in-depth, unprecedented characterization of functionalized photo-crosslinkable biopolymers. Moreover, our strategy enabled to visualize the spatial distribution of the modifications within the overall structure of the protein. Proteomics has proven to provide unprecedented insight in the distribution of photo-crosslinkable moieties along the protein backbone, undoubtedly contributing to superior functional biomaterial design to serve regenerative medicine.展开更多
文摘Magnesium(Mg)and its alloys have become a hot research topic in various industries owing to the specific physical and chemical properties.However,high corrosion rate is considered the key lifetime-limiting.Plasma electrolytic oxidation(PEO)method is a simple strategy to deposit an oxide layer on the surface of light metals such as magnesium alloys,to control corrosion rate and promote some other properties,depending on their performances.Nevertheless,their features including their micropore size,distribution,and interconnectivity,and microcracks have not been improved to an acceptable level to support long-term performances of the magnesium-based substrates.Studies have introduced micro/nano-enabled approaches to enhance various properties of PEO coatings such as corrosion resistance,tribological properties,self-healing ability,bioactivity,biocompatibility,antibacterial properties,or catalytic performances.These strategies consist of incorporating of micro and nanoparticles into the PEO layers to produce multi-functional surfaces or the formation of multi-layered coatings to cover the defects of PEO coatings.In this perspective,the present paper aims to overview various nano/micro-enabled strategies to promote the properties of PEO coatings on magnesium alloys.The main focus is given to the functional changes that occurred in response to the incorporation of various types of nano/micro-structures into the PEO coatings on magnesium alloys.
文摘The aim of this work was to study the influence of the different synthesis processes on microstructural and morphological characteristics and distribution of hydroxyapatite-bioactive glass(HAp-BG)composite nanopowders obtained by sol-gel method.HAp-BG composite nanopowders with 20 wt%bioactive glass were prepared using a sol-gel method via four routes:(I)mixing the prepared HAp solution with BG solution before aging time;(II)mixing the prepared BG solution with the prepared HAp gel after gelation;(III)mixing the calcined BG nanopowders with the prepared HAp solution;and(IV)mixing the two prepared calcined nanopowders by mechanochemical activation.The prepared nanopowders were evaluated and studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS),Fourier transform infrared(FTIR),transmission electron diffraction(TEM)and Brunauer-Emmet-Teller(BET)method to investigate the phase structure,microstructure and morphology,functional groups,and the size and distribution of nanopowders.Results indicated that morphology,crystallinity,crystallite size and specific surface area(SSA)of the powders are highly correspondent to the process and type of synthesis method.These findings suggest that the modified sol-gel derived HAp-BG composite nanopowders are expected to efficiently provide a possibility to produce a good candidate to use for fabrication of a bulk nanostructured HAp-BG composite for bone tissue engineering.
基金The work was supperted by the Alexander von Humboldt foundation(to FG).
文摘Cartilage injuries are common problems that increase with the population aging.Cartilage is an avascular tissue with a relatively low level of cellular mitotic activity,which makes it impossible to heal spontaneously.To compensate for this problem,three-dimensional bio-printing has attracted a great deal of attention in cartilage tissue engineering.This emerging technology aims to create three-dimensional functional scaffolds by accurately depositing layer-by-layer bio-inks composed of biomaterial and cells.As a novel bio-ink,a decellularized extracellular matrix can serve as an appropriate substrate that contains all the necessary biological cues for cellular interactions.Here,this review is intended to provide an overview of decellularized extracellular matrix-based bio-inks and their properties,sources,and preparation process.Following this,decellularized extracellular matrix-based bio-inks for cartilage tissue engineering are discussed,emphasizing cell behavior and in-vivo applications.Afterward,the current challenges and future outlook will be discussed to determine the conclusing remarks.
基金MMwould like to thank FondsWetenschappelijk Onderzoek(FWO)for financial support(SB PhD fellow at FWO,Grant No.3SB5619)AM has also received funding from Fonds Wetenschappelijk Onderzoek(Grant No.12Z2918N).
文摘Background:Nowadays,a wide range of wound dressings is already commercially available.The selection of the dressing is of paramount importance as inappropriate wound management and dressing selection can delay the wound healing process.Not only can this be distressing for the patient,but it can also contribute to complications such as maceration and subsequent infection.Many researchers are targeting the design of dressings with superior properties over existing commercial dressings.However,reported results in the state-of-the-art are rarely benchmarked against commercial dressings.The aim of this study was to determine several characteristics of a large variety of the most frequently used commercial wound dressings,providing an overview for both practitioners and researchers.Methods:For this comparative study,11 frequently used commercial wound dressings were selected,representing the different types.The morphology was studied using scanning electron microscopy.The dressings were characterized in terms of swelling capacity(water,phosphate buffered saline and simulated wound fluid),moisture vapour transmission rate(MVTR)and moisture uptake capacity(via dynamic vapour sorption)as well as mechanical properties using tensile testing and texturometry.Results:The selected dressings showed distinctive morphological differences(fibrous,porous and/or gel)which was reflected in the different properties.Indeed,the swelling capacities ranged between 1.5 and 23.2 g/g(water),2.1 and 17.6 g/g(phosphate buffered saline)or 2.9 and 20.8 g/g(simulated wound fluid).The swelling capacity of the dressings in water increased even further upon freeze-drying,due to the formation of pores.The MVTR values varied between 40 and 930 g/m^(2)/24 h.The maximal moisture uptake capacity varied between 5.8%and 105.7%at 95%relative humidity.Some commercial dressings exhibited a superior mechanical strength,due to either being hydrophobic or multi-layered.Conclusions:The present work not only offers insight into a valuable toolbox of suitable wound dressing characterization techniques,but also provides an extensive landscaping of commercial dressings along with their physico-chemical properties,obtained through reproducible experimen-tal protocols.Furthermore,it ensures appropriate benchmark values for commercial dressings in all forthcoming studies and could aid researchers with the development of novel modern wound dressings.The tested dressings either exhibited a high strength or a high swelling capacity,suggesting that there is still a strong potential in the wound dressings market for dressings that possess both.
基金The authors acknowledge the IBiSA network for financial support of the USR 3290(MSAP)proteomics facility TOP_OMICS.The mass spec-trometers were funded by the University of Lille,the CNRS,the Region Hauts-de-France and the European Regional Development Fund (ERDF).
文摘The distribution of photo-crosslinkable moieties onto a protein backbone can affect a biomaterial’s crosslinking behavior, and therefore also its mechanical and biological properties. A profound insight in this respect is essential for biomaterials exploited in tissue engineering and regenerative medicine. In the present work, photo-crosslinkable moieties have been introduced on the primary amine groups of: (i) a recombinant collagen peptide (RCPhC1) with a known amino acid (AA) sequence, and (ii) bovine skin collagen (COL BS) with an unknown AA sequence. The degree of substitution (DS) was quantified with two conventional techniques: an ortho-phthalic dialdehyde (OPA) assay and ^(1)H NMR spectroscopy. However, neither of both provides information on the exact type and location of the modified AAs. Therefore, for the first time, proteomic analysis was evaluated herein as a tool to identify functionalized AAs as well as the exact position of photo-crosslinkable moieties along the AA sequence, thereby enabling an in-depth, unprecedented characterization of functionalized photo-crosslinkable biopolymers. Moreover, our strategy enabled to visualize the spatial distribution of the modifications within the overall structure of the protein. Proteomics has proven to provide unprecedented insight in the distribution of photo-crosslinkable moieties along the protein backbone, undoubtedly contributing to superior functional biomaterial design to serve regenerative medicine.
