Density functional methods have been used for the calculation of electronic structures, electronic transitions, vertical electron affinities and intermolecular reorganization energies for tri-aryl substituted dibenzot...Density functional methods have been used for the calculation of electronic structures, electronic transitions, vertical electron affinities and intermolecular reorganization energies for tri-aryl substituted dibenzothiophenes. These model compounds were then compared to the predicted values for dibenzo[b,d]thiophen-2-yltriphenylsilane (DBTSI 2) and to dibenzo[b,d]thiophene-2,8-diylbis(diphenylphosphine oxide) (PO15), known electron transport molecules. The results indicate that these model compounds can be used in a blue OLED system.展开更多
Cancer is considered one of the most lethal diseases responsible for causing deaths worldwide.Although there have been many breakthroughs in anticancer development,cancer remains the major cause of death globally.In t...Cancer is considered one of the most lethal diseases responsible for causing deaths worldwide.Although there have been many breakthroughs in anticancer development,cancer remains the major cause of death globally.In this regard,targeting cancer-causing enzymes is one of the efficient therapeutic strategies.Biological functions like cell cycle,transcription,metabolism,apoptosis,and other depend primarily on cyclin-dependent kinases(CDKs).These enzymes help in the replication of DNA in the normal cell cycle process,and deregulation in the functioning of any CDK can cause abnormal cell growth,which leads to cancer.This review is focused on anticancer drug discovery against cell cycle CDK enzyme using an in silico technique,i.e.,molecular docking studies.Molecular docking helps in deciphering the key interactions formed within the inhibitor and the respective enzyme.This concise study provides an overview of the most current in silico research advancements made in the field of anticancer drug discovery.The findings presented in the current review article can help in understanding the nature of inhibitor-target interactions and provide information on the structural and molecular prerequisites for the inhibition of cell cycle CDKs.展开更多
This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The...This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The addition of non-halogen flame retardants(FRs)including aluminum trihydroxide(ATH),triphenyl phosphate(TPP),and diammonium phosphate(DAP)leads to markedly enhanced thermal sta-bility and fire resistance of the PU/nSiO_(2)/FRs nanocomposites,resulting in achieving UL-94 HB standard.In particular,the nanocomposites met the UL-94 V-0 criteria thanks to the inclusion of DAP at 25 phr.The LOI value of the nanocomposites reached 26%which is much higher than that of PU/nSiO_(2)nanocompos-ite,about 20%.In order to further understand the fire-proof mechanism,the residue char layer remaining of the PU/nSiO_(2)/FRs nanocomposites after being burned was also investigated by scanning electron mi-croscopy(SEM)and Fourier transform infrared(FTIR).In addition,the microstructure,thermal stability,thermal conductivity,and mechanical properties of nanocomposites were also evaluated in this study.展开更多
α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commerciall...α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commercially available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and surface morphologies were used as starting materials to synthesize high percentage α-HH via a hydrothermal method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size distribution, morphology and phase composition of the raw materials were evaluated before synthesis. SEM results revealed that DH-L consisted of irregular large particles, while DH-M and DH-S were composed of plate-like particles with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal method, specifically, 105 °C/90 min for DH-L (achieving 98.8% HH), 105°C/30 min for DH-M (achieving 96.7% HH) and 100°C/45 min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material (DH) have significant influences on not only the rate of phase transition but also the morphology of the synthesized α-HH. Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation of high percentage α-HH is feasible via a hydrothermal method and the process can be further scaled up to industrial scale production.展开更多
Conductivity dopants with processing properties suitable for industrial applications are of importance to the organic electronics field. However, the number of commercially available organic molecular dopants is limit...Conductivity dopants with processing properties suitable for industrial applications are of importance to the organic electronics field. However, the number of commercially available organic molecular dopants is limited. The electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4-TCNQ) is the most utilized P-dopant;however, it has high volatility and a poor sticking coefficient, which makes it difficult to control doping levels and prevent vacuum system contamination. A design concept for P-type molecular dopants based on the TCNQ core which are substituted to improve processing properties without sacrificing the electronic properties necessary is presented. The correlation between the lowest unoccupied molecular orbital (LUMO) energy and the position of substitution as well as the choice of linker is evaluated. The position of substitution as well as the choice of linker has a significant effect on the electronic properties. However, the geometry of the substituted molecules was not significantly distorted from that of the parent F4-TCNQ, and the electron density was delocalized on the TCNQ core. We also put forward four possible molecular dopants with suitable energy levels.展开更多
The synthesis of <span>nitrogen containing</span> heterocycles is of particular interest in the pharmaceutical industry due to the range of biological activities exhibited by such compounds. Their synthesi...The synthesis of <span>nitrogen containing</span> heterocycles is of particular interest in the pharmaceutical industry due to the range of biological activities exhibited by such compounds. Their synthesis using multicomponent reactions saves steps and minimizes waste generation. The bismuth (III) chloride multicomponent synthesis of a series of hexahydroimidazo[1, 2-</span></span><span><span><span style="font-family:""><i></span></span></span><span><span><i><span style="font-family:"">a</span></i></span></span><span><span><i><span style="font-family:""></i></span></i></span></span><span><span><span style="font-family:"">]pyridines is reported. <span>Bismuth (III) compounds are especially attractive from a green chemistry perspective because they are remarkably nontoxic, non-corrosive <span>and</span> relatively </span>inexpensive. The reported method avoids chromatography and an aqueous waste stream to afford the products in a very <span>mass efficient</span> manner.展开更多
Composite materials are becoming essential in solving medical technology challenges due to their ability to integrate the functional advantages of ceramics,polymers,metals,and natural components.Unlike monolithic mate...Composite materials are becoming essential in solving medical technology challenges due to their ability to integrate the functional advantages of ceramics,polymers,metals,and natural components.Unlike monolithic materials,composites offer tunability,making them central to emerging innovations in medical devices,tissue engineering,and drug delivery.This commentary explores how composites can pave the way for next-generation biomedical technologies and highlights current translational bottlenecks.展开更多
Increasing interest in the role of ions such as calcium and strontium in bone formation has called for the investigation of multifunctional ion-doped implant coatings. Mesoporous titania coatings incorporating calcium...Increasing interest in the role of ions such as calcium and strontium in bone formation has called for the investigation of multifunctional ion-doped implant coatings. Mesoporous titania coatings incorporating calcium or strontium enabled a unique pore morphology and potential for drug delivery. Coatings were produced on titanium by an evaporation induced self-assembly method with the addition of calcium or strontium to the sol causing a shift in morphology from a hexagonally-packed to a worm-like porous network. Pore sizes ranged from 3.8 - 5 nm and coatings exhibited high surface areas between 181 - 215.5 m2/g, as measured by N2 adsorption-desorption. Coatings were loaded with 1 mg/ml Cephalothin, and showed sustained release of the antibiotic over one week in vitro. Cell studies confirmed that the ion addition had no toxic effect on human-like osteoblastic SaOS-2 cells. The results of this study suggest the potential for mesoporous coatings with calcium or strontium incorporation for direct bone-interfacing and combined drug delivery implant applications.展开更多
The synthesis and structures of two novel zwitterionic ruthenium triazolato complexes are reported. The treatment of the ruthenium azido complex [Ru]-N3 (1, [Ru] = (η5-C5H5)(dppe)Ru, dppe = Ph2PCH2CH2PPh2) with an ex...The synthesis and structures of two novel zwitterionic ruthenium triazolato complexes are reported. The treatment of the ruthenium azido complex [Ru]-N3 (1, [Ru] = (η5-C5H5)(dppe)Ru, dppe = Ph2PCH2CH2PPh2) with an excess of ethyl propiolate in CHCl3 or CH2Cl2 under ambient conditions for 15 days results in the formation of a mixture of the Z- and E-forms of N(1)-bound ruthenium 3-ethylacryl-4-carboxylate-3H-1,2,3-triazolato complexes [Ru]N3(CH=CHCO2Et)C2H(CO2) (Z-3) and (E-3) in a ratio of ca. 5:2. The structures of E-3 and Z-3 were confirmed by single-crystal X-ray diffraction analysis and fully characterized by 1H, 31P, 13C NMR and IR spectroscopy, mass spectrometry, and elemental analysis. The negatively charged carboxylate moieties of the zwitterionic ruthenium triazolato complexes Z-3 and Z-3 are highly nucleophilic and reactive toward a variety of electrophiles, making Z-3 and Z-3 potential starting materials for the development of biologically active 1,2,3-triazole derivatives.展开更多
Nanotopographical features are found to have significant effects on bone behavior. In the present study, nanoporous aluminas with different pore sizes (20, 100 and 200 nm in diameter), were evaluated for their osteoin...Nanotopographical features are found to have significant effects on bone behavior. In the present study, nanoporous aluminas with different pore sizes (20, 100 and 200 nm in diameter), were evaluated for their osteoinductive and drug eluting properties. W20-17 marrow stromal cells were seeded on nanoporous alumina with and without the addition of BMP-2. Although cell proliferation was not affected by pore size, osteogenic differentiation was 200 nm as compared to 20 and 100 nm pores induced higher alkaline phosphatase activity (ALP) and osteocalcin expression levels, thus indicating osteoblastic differentiation. Cell morphology revealed that cells cultured on 20 nm pores adopted a rounded shape, while larger pores (200 nm) elicited an elongated morphology. Furthermore, ALP expression levels were consistently higher on BMP-2 loaded nanoporous alumina surfaces compared to unloaded surfaces, indicating that not only is nanoporous alumina osteoinductive, but also has the potential to be used as a drug eluting bone-implant coating.展开更多
New methods to improve the bone response to metallic implants are still emerging, ranging from surface modifications of the metal to coatings and drug delivery. One further development of coatings on implants is to in...New methods to improve the bone response to metallic implants are still emerging, ranging from surface modifications of the metal to coatings and drug delivery. One further development of coatings on implants is to incorporate bioactive ions in order to stimulate the bone response without the need of drug delivery. The aim of the current study is to prepare apatite coatings containing Sr and Si using a solution method, for the purpose of further optimising the bone response to metal implants. Titanium substrates were activated to induce the formation of coatings in modified PBS solutions. Soaking in PBS solutions with different concentrations of strontium and silicate at 37℃ or 60℃ produced coatings with different morphologies, thicknesses and compositions. Ion release experiments showed simultaneous release of Sr and Si from the coatings both in PBS and Tris-HCl. Analysis of the results using the Korsmeyer-Peppas model indicate that the release of ions from the coatings was a combination of Fickian diffusion and degradation of the coatings. This study shows that it is possible to coat Ti substrates with modified apatite with ion release functionality and thereby increase the possibilities for a tailored bone response in vivo.展开更多
Herein, we show that incorporation of ions during biomimetic coating deposition may be utilized to tailor the drug loading capacity of hydroxyapatite (HA) coatings. Pure biomimetic HA (HA-B) and Si-doped equivalents (...Herein, we show that incorporation of ions during biomimetic coating deposition may be utilized to tailor the drug loading capacity of hydroxyapatite (HA) coatings. Pure biomimetic HA (HA-B) and Si-doped equivalents (SiHA-B) where deposited by a biomimetic process onto titanium dioxide covered titanium substrates. The antibiotic Cephalothin was incorporated into the coatings by adsorptive loading and the release was studied in-vitro. SiHA-B coatings exhibited superior drug incorporation capacity compared to pure HA-B coatings, resulting in a drug release profile dominated by an initial 10 min burst effect while a more prolonged 10 hour release was observed from HA-B coatings. The results emphasize the possibility to impact the drug release kinetics from implant coatings by selective doping elements and the use of thin, biomimetic HA-coatings as drug delivery vehicles. Functionalizing metal implants with SiHA-B coatings presents an interesting strategy towards creating synergetic effects through ion- and antibiotic release and, hence, contributing both towards preventing post-surgical infections while at the same time enhancing the bone-bonding ability.展开更多
Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite co...Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite coatings through a biomineralization method, which mimics an in vitro mineralization process. The surface composition is tested with X-ray diffraction and X-ray photoelectron spectroscopy, and the surface morphology is characterized with scanning electron microscopy. Compared with pure hydroxyapatite coating, the strontium, silicon, and fluoride substituted apatite coatings show different morphology as spherical, needle-like, and nano-flake-like, individually. The crystal size of these biomimetic hydroxyapatite coatings decreased after ion substitution. The results of the analysis of surface composition present the ion substitutions are increased with the increasing of ion concentrations in the soaking solution. That means the ion incorporation into the apatite structure based on the biomineralization method could not only vary the ion content in but also change the morphology of the apatite coatings. Herein, the role of ion substitution is considered from the point of view of materials science at the micro structural and surface chemistry levels.展开更多
The early fixation of bone screws after surgical implantation still remains a challenge in the field of traumatology. Whilst hydroxyapatite (HA) coatings are known to enhance the fixation of implants;their removal at ...The early fixation of bone screws after surgical implantation still remains a challenge in the field of traumatology. Whilst hydroxyapatite (HA) coatings are known to enhance the fixation of implants;their removal at a later time-point may be problematic. An HA coating has been developed to demonstrate that both implant fixation and safe removal are feasible in the same design. Accordingly the aim of this study was to compare the In-Vivo performance of thin biomimetic HA coated titanium screws to uncoated counterparts used as control after bilateral implantation in the femoral condyle of 36 New Zealand White Rabbits. The screws were analysed macroscopically, by histology, micro-CT and biomechanically at both two and six weeks post-implantation. The HA coated screws demonstrated excellent biocompatibility. At two weeks the HA coated screws demonstrated a significant increase in removal torque values as well as a strong trend towards higher pull-out forces. In addition histology confirmed a higher degree of osseointegration and direct bone to implant contact. At six weeks no difference in pull-out force and removal torque could be detected. SEM images confirmed the absence of any residual HA coating indicating a fast coating degradation In-Vivo. The low level of removal torque after full osseointegration at 6 weeks supports the feasibility of safe and easy removal of the implant. The HA coating under study appears to offer a unique characteristic of enhanced fixation with a minimal increase in removal torque after full osseointegration. This may be of value in clinical applications where it is necessary to assure both screw fixation and later removal.展开更多
Natural biominerals such as bone and teeth show how composite structures can combine organic and inorganic components to achieve both strong mechanical performance and essential biological functions.Inspired by these ...Natural biominerals such as bone and teeth show how composite structures can combine organic and inorganic components to achieve both strong mechanical performance and essential biological functions.Inspired by these systems,composite materials are becoming an increasingly important class of biomaterials capable of meeting the growing complexity of biomedical challenges.展开更多
There is a constant need for materials that combine hemostasis and osteogenesis in orthopedic surgery.Current hemostatic materials lack biodegradability,osteogenic properties,and hemostatic efficacy.In this study,we d...There is a constant need for materials that combine hemostasis and osteogenesis in orthopedic surgery.Current hemostatic materials lack biodegradability,osteogenic properties,and hemostatic efficacy.In this study,we developed a wax-like co-doped polyphosphate(CoPPW)by chelating sodium polyphosphate with cationic ions(Ca^(2+),Mg^(2+),and Sr^(2+)).Our results demonstrate that CoPPW was malleable and degraded optimally,releasing Mg^(2+)and Sr^(2+)ions initially and losing weight over 4 weeks.In vitro,CoPPW promoted better cell proliferation and osteogenic differentiation than beeswax,likely due to ion release.RT-PCR and transcriptome sequencing revealed that CoPPW significantly upregulated osteogenesis-related genes and bone-related protein expression.The activation of the PI3K/AKT signalling pathway confirmed osteogenesis,while the coagulation cascade pathway indicated effective hemostasis.In vivo,CoPPW was more effective in promoting bone regeneration and hemostasis compared to bone wax.Overall,CoPPW exhibits excellent hemostatic and osteogenic effects,making it a promising candidate for bone repair applications.展开更多
Repositioning and securing the cranial bone flap after craniotomy remain significant challenges in neurosurgery.Traditional fixation methods often suffer from weak mechanical strength,bioinertness,limited osteogenic c...Repositioning and securing the cranial bone flap after craniotomy remain significant challenges in neurosurgery.Traditional fixation methods often suffer from weak mechanical strength,bioinertness,limited osteogenic ca-pacity,and a lack of antibacterial properties,complicating clinical outcomes.Recent medical adhesives offer superior fixation but face significant limitations in cranial bone applications.In this study,we explored the application of PAH(Poly(allylamine)hydrochloride)-TPP(Tripolyphosphate)coacervate(PT)as a bone adhe-sive.The PT coacervate demonstrated excellent anti-swelling(anti-swelling ratio less than 1%),self-healing,and injectable properties,as well as exceptional shape adaptability and cytocompatibility.Adhesion tests revealed its outstanding adhesion(99.06±11.76 kPa for lap shear and 121.42±16.73 kPa for end to end),long-term durability,and tunable adhesion strength.Furthermore,the coacervate demonstrated broad-spectrum antibac-terial activity against both Gram-positive and Gram-negative bacteria(antibacterial rate more than 90%),with mechanistic studies revealing promising strategies to address localized and systemic drug-resistant infections.Additionally,the coacervate’s self-mineralizing properties significantly enhanced its osteogenic performance.In vivo studies confirmed its effective fixation,robust antibacterial activity,and improved osteogenesis,under-scoring its suitability for cranial bone flap repositioning and fixation after craniotomy.In summary,this coac-ervate adhesive offers a promising therapeutic solution for addressing the challenges of cranial flap fixation in neurosurgery.展开更多
The dual role of reactive oxygen and nitrogen species(RONS)in physiological and pathological processes in biological systems has been widely reported.It has been recently suggested that the regulation of RONS levels u...The dual role of reactive oxygen and nitrogen species(RONS)in physiological and pathological processes in biological systems has been widely reported.It has been recently suggested that the regulation of RONS levels under physiological and pathological conditions is a potential therapy to promote health and treat diseases,respectively.Injectable hydrogels have been emerging as promising biomaterials for RONS-related biomedical applications owing to their excellent biocompatibility,three-dimensional and extracellular matrix-mimicking structures,tunable properties and easy functionalization.These hydrogels have been developed as advanced injectable platforms for locally generating or scavenging RONS,depending on the specific conditions of the target disease.In this review article,the design principles and mechanism by which RONS are generated/scavenged from hydrogels are outlined alongside a discussion of their in vitro and in vivo evaluations.Additionally,we highlight the advantages and recent developments of these injectable RONS-controlling hydrogels for regenerativemedicines and tissue engineering applications.展开更多
文摘Density functional methods have been used for the calculation of electronic structures, electronic transitions, vertical electron affinities and intermolecular reorganization energies for tri-aryl substituted dibenzothiophenes. These model compounds were then compared to the predicted values for dibenzo[b,d]thiophen-2-yltriphenylsilane (DBTSI 2) and to dibenzo[b,d]thiophene-2,8-diylbis(diphenylphosphine oxide) (PO15), known electron transport molecules. The results indicate that these model compounds can be used in a blue OLED system.
基金the financial supports from the Natural Science Foundation of Hunan Province, China (Nos. 2020JJ4114, 2016JJ3151)the National Natural Science Foundation of China (No. 51601229)+2 种基金the Young Elite Scientist Sponsorship Program by CAST, China (No. 2015QNRC001)the Hunan Province Innovation Platform and Talent Plan Project, China (No. 2015RS4001)the Open-end Fund for the Valuable and Precision Instruments of Central South University, China (No. CSUZC201815)。
基金financially supported by the Natural Science Foundation of Hunan Province,China(Nos.2020JJ4114,2016JJ3151)the National Natural Science Foundation of China(No.51601229)+2 种基金the Young Elite Scientist Sponsorship Program by CAST,China(No.2015QNRC001)the Hunan Province Innovation Platform and Talent Plan,China(No.2015RS4001)the Open-End Fund for the Valuable and Precision Instruments of Central South University,China(No.CSUZC201815)。
文摘Cancer is considered one of the most lethal diseases responsible for causing deaths worldwide.Although there have been many breakthroughs in anticancer development,cancer remains the major cause of death globally.In this regard,targeting cancer-causing enzymes is one of the efficient therapeutic strategies.Biological functions like cell cycle,transcription,metabolism,apoptosis,and other depend primarily on cyclin-dependent kinases(CDKs).These enzymes help in the replication of DNA in the normal cell cycle process,and deregulation in the functioning of any CDK can cause abnormal cell growth,which leads to cancer.This review is focused on anticancer drug discovery against cell cycle CDK enzyme using an in silico technique,i.e.,molecular docking studies.Molecular docking helps in deciphering the key interactions formed within the inhibitor and the respective enzyme.This concise study provides an overview of the most current in silico research advancements made in the field of anticancer drug discovery.The findings presented in the current review article can help in understanding the nature of inhibitor-target interactions and provide information on the structural and molecular prerequisites for the inhibition of cell cycle CDKs.
基金funded by the Vietnam National University Ho Chi Minh City(VNU-HCM)under grant number C2022-18-41.
文摘This study focuses on the improvement of the thermal stability and flame-retardant performance of polyurethane(PU)foam by using effective flame-retardant additives and nano silica(nSiO_(2))particles from rice husk.The addition of non-halogen flame retardants(FRs)including aluminum trihydroxide(ATH),triphenyl phosphate(TPP),and diammonium phosphate(DAP)leads to markedly enhanced thermal sta-bility and fire resistance of the PU/nSiO_(2)/FRs nanocomposites,resulting in achieving UL-94 HB standard.In particular,the nanocomposites met the UL-94 V-0 criteria thanks to the inclusion of DAP at 25 phr.The LOI value of the nanocomposites reached 26%which is much higher than that of PU/nSiO_(2)nanocompos-ite,about 20%.In order to further understand the fire-proof mechanism,the residue char layer remaining of the PU/nSiO_(2)/FRs nanocomposites after being burned was also investigated by scanning electron mi-croscopy(SEM)and Fourier transform infrared(FTIR).In addition,the microstructure,thermal stability,thermal conductivity,and mechanical properties of nanocomposites were also evaluated in this study.
基金financial support from the Swedish Innovation Agency(VINNOVA)and China Scholarship Council(CSC).
文摘α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commercially available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and surface morphologies were used as starting materials to synthesize high percentage α-HH via a hydrothermal method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size distribution, morphology and phase composition of the raw materials were evaluated before synthesis. SEM results revealed that DH-L consisted of irregular large particles, while DH-M and DH-S were composed of plate-like particles with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal method, specifically, 105 °C/90 min for DH-L (achieving 98.8% HH), 105°C/30 min for DH-M (achieving 96.7% HH) and 100°C/45 min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material (DH) have significant influences on not only the rate of phase transition but also the morphology of the synthesized α-HH. Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation of high percentage α-HH is feasible via a hydrothermal method and the process can be further scaled up to industrial scale production.
文摘Conductivity dopants with processing properties suitable for industrial applications are of importance to the organic electronics field. However, the number of commercially available organic molecular dopants is limited. The electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4-TCNQ) is the most utilized P-dopant;however, it has high volatility and a poor sticking coefficient, which makes it difficult to control doping levels and prevent vacuum system contamination. A design concept for P-type molecular dopants based on the TCNQ core which are substituted to improve processing properties without sacrificing the electronic properties necessary is presented. The correlation between the lowest unoccupied molecular orbital (LUMO) energy and the position of substitution as well as the choice of linker is evaluated. The position of substitution as well as the choice of linker has a significant effect on the electronic properties. However, the geometry of the substituted molecules was not significantly distorted from that of the parent F4-TCNQ, and the electron density was delocalized on the TCNQ core. We also put forward four possible molecular dopants with suitable energy levels.
文摘The synthesis of <span>nitrogen containing</span> heterocycles is of particular interest in the pharmaceutical industry due to the range of biological activities exhibited by such compounds. Their synthesis using multicomponent reactions saves steps and minimizes waste generation. The bismuth (III) chloride multicomponent synthesis of a series of hexahydroimidazo[1, 2-</span></span><span><span><span style="font-family:""><i></span></span></span><span><span><i><span style="font-family:"">a</span></i></span></span><span><span><i><span style="font-family:""></i></span></i></span></span><span><span><span style="font-family:"">]pyridines is reported. <span>Bismuth (III) compounds are especially attractive from a green chemistry perspective because they are remarkably nontoxic, non-corrosive <span>and</span> relatively </span>inexpensive. The reported method avoids chromatography and an aqueous waste stream to afford the products in a very <span>mass efficient</span> manner.
文摘Composite materials are becoming essential in solving medical technology challenges due to their ability to integrate the functional advantages of ceramics,polymers,metals,and natural components.Unlike monolithic materials,composites offer tunability,making them central to emerging innovations in medical devices,tissue engineering,and drug delivery.This commentary explores how composites can pave the way for next-generation biomedical technologies and highlights current translational bottlenecks.
基金supported by BIOMATCELL,VINN Excellence Center of Biomaterials and Cell Therapy,Gothenburg,Sweden and a VINNOVA VINNMER[grant 2010-01907]a STINT Institutional Grant for Younger Researchers.
文摘Increasing interest in the role of ions such as calcium and strontium in bone formation has called for the investigation of multifunctional ion-doped implant coatings. Mesoporous titania coatings incorporating calcium or strontium enabled a unique pore morphology and potential for drug delivery. Coatings were produced on titanium by an evaporation induced self-assembly method with the addition of calcium or strontium to the sol causing a shift in morphology from a hexagonally-packed to a worm-like porous network. Pore sizes ranged from 3.8 - 5 nm and coatings exhibited high surface areas between 181 - 215.5 m2/g, as measured by N2 adsorption-desorption. Coatings were loaded with 1 mg/ml Cephalothin, and showed sustained release of the antibiotic over one week in vitro. Cell studies confirmed that the ion addition had no toxic effect on human-like osteoblastic SaOS-2 cells. The results of this study suggest the potential for mesoporous coatings with calcium or strontium incorporation for direct bone-interfacing and combined drug delivery implant applications.
文摘The synthesis and structures of two novel zwitterionic ruthenium triazolato complexes are reported. The treatment of the ruthenium azido complex [Ru]-N3 (1, [Ru] = (η5-C5H5)(dppe)Ru, dppe = Ph2PCH2CH2PPh2) with an excess of ethyl propiolate in CHCl3 or CH2Cl2 under ambient conditions for 15 days results in the formation of a mixture of the Z- and E-forms of N(1)-bound ruthenium 3-ethylacryl-4-carboxylate-3H-1,2,3-triazolato complexes [Ru]N3(CH=CHCO2Et)C2H(CO2) (Z-3) and (E-3) in a ratio of ca. 5:2. The structures of E-3 and Z-3 were confirmed by single-crystal X-ray diffraction analysis and fully characterized by 1H, 31P, 13C NMR and IR spectroscopy, mass spectrometry, and elemental analysis. The negatively charged carboxylate moieties of the zwitterionic ruthenium triazolato complexes Z-3 and Z-3 are highly nucleophilic and reactive toward a variety of electrophiles, making Z-3 and Z-3 potential starting materials for the development of biologically active 1,2,3-triazole derivatives.
基金funded by Ollie och Elof Ericssons Stifelse for vetenskaplig forskning,Stiftelsen Lars Hiertas Minne and STINT(Stiftelsen for internationalisering av hogre utbildning och forskning).
文摘Nanotopographical features are found to have significant effects on bone behavior. In the present study, nanoporous aluminas with different pore sizes (20, 100 and 200 nm in diameter), were evaluated for their osteoinductive and drug eluting properties. W20-17 marrow stromal cells were seeded on nanoporous alumina with and without the addition of BMP-2. Although cell proliferation was not affected by pore size, osteogenic differentiation was 200 nm as compared to 20 and 100 nm pores induced higher alkaline phosphatase activity (ALP) and osteocalcin expression levels, thus indicating osteoblastic differentiation. Cell morphology revealed that cells cultured on 20 nm pores adopted a rounded shape, while larger pores (200 nm) elicited an elongated morphology. Furthermore, ALP expression levels were consistently higher on BMP-2 loaded nanoporous alumina surfaces compared to unloaded surfaces, indicating that not only is nanoporous alumina osteoinductive, but also has the potential to be used as a drug eluting bone-implant coating.
基金This work was supported by BIOMATCELL,VINN Ex-cellence Center of Biomaterials and Cell Therapy
文摘New methods to improve the bone response to metallic implants are still emerging, ranging from surface modifications of the metal to coatings and drug delivery. One further development of coatings on implants is to incorporate bioactive ions in order to stimulate the bone response without the need of drug delivery. The aim of the current study is to prepare apatite coatings containing Sr and Si using a solution method, for the purpose of further optimising the bone response to metal implants. Titanium substrates were activated to induce the formation of coatings in modified PBS solutions. Soaking in PBS solutions with different concentrations of strontium and silicate at 37℃ or 60℃ produced coatings with different morphologies, thicknesses and compositions. Ion release experiments showed simultaneous release of Sr and Si from the coatings both in PBS and Tris-HCl. Analysis of the results using the Korsmeyer-Peppas model indicate that the release of ions from the coatings was a combination of Fickian diffusion and degradation of the coatings. This study shows that it is possible to coat Ti substrates with modified apatite with ion release functionality and thereby increase the possibilities for a tailored bone response in vivo.
基金The Swedish Research Council,the Carl Trygger Foundation,the Goran Gustafsson Foundation,the Swedish Foundation for Strategic Research and Vinnova are acknowledged for financially supporting our research
文摘Herein, we show that incorporation of ions during biomimetic coating deposition may be utilized to tailor the drug loading capacity of hydroxyapatite (HA) coatings. Pure biomimetic HA (HA-B) and Si-doped equivalents (SiHA-B) where deposited by a biomimetic process onto titanium dioxide covered titanium substrates. The antibiotic Cephalothin was incorporated into the coatings by adsorptive loading and the release was studied in-vitro. SiHA-B coatings exhibited superior drug incorporation capacity compared to pure HA-B coatings, resulting in a drug release profile dominated by an initial 10 min burst effect while a more prolonged 10 hour release was observed from HA-B coatings. The results emphasize the possibility to impact the drug release kinetics from implant coatings by selective doping elements and the use of thin, biomimetic HA-coatings as drug delivery vehicles. Functionalizing metal implants with SiHA-B coatings presents an interesting strategy towards creating synergetic effects through ion- and antibiotic release and, hence, contributing both towards preventing post-surgical infections while at the same time enhancing the bone-bonding ability.
基金This work was supported by BIOMATCELL,VINN Ex-cellence Center of Biomaterials and Cell Therapy.
文摘Fabrication of trace elements incorporated apatite coating could combine the ions’ pharmaceutical effect into the materials. In this study, strontium, silicon, and fluoride ions have been incorporated into apatite coatings through a biomineralization method, which mimics an in vitro mineralization process. The surface composition is tested with X-ray diffraction and X-ray photoelectron spectroscopy, and the surface morphology is characterized with scanning electron microscopy. Compared with pure hydroxyapatite coating, the strontium, silicon, and fluoride substituted apatite coatings show different morphology as spherical, needle-like, and nano-flake-like, individually. The crystal size of these biomimetic hydroxyapatite coatings decreased after ion substitution. The results of the analysis of surface composition present the ion substitutions are increased with the increasing of ion concentrations in the soaking solution. That means the ion incorporation into the apatite structure based on the biomineralization method could not only vary the ion content in but also change the morphology of the apatite coatings. Herein, the role of ion substitution is considered from the point of view of materials science at the micro structural and surface chemistry levels.
基金part of the 7^(th) Framework programme—BIODESIGN as well as the Swedish Science Council is gratefully acknowledged for financial support
文摘The early fixation of bone screws after surgical implantation still remains a challenge in the field of traumatology. Whilst hydroxyapatite (HA) coatings are known to enhance the fixation of implants;their removal at a later time-point may be problematic. An HA coating has been developed to demonstrate that both implant fixation and safe removal are feasible in the same design. Accordingly the aim of this study was to compare the In-Vivo performance of thin biomimetic HA coated titanium screws to uncoated counterparts used as control after bilateral implantation in the femoral condyle of 36 New Zealand White Rabbits. The screws were analysed macroscopically, by histology, micro-CT and biomechanically at both two and six weeks post-implantation. The HA coated screws demonstrated excellent biocompatibility. At two weeks the HA coated screws demonstrated a significant increase in removal torque values as well as a strong trend towards higher pull-out forces. In addition histology confirmed a higher degree of osseointegration and direct bone to implant contact. At six weeks no difference in pull-out force and removal torque could be detected. SEM images confirmed the absence of any residual HA coating indicating a fast coating degradation In-Vivo. The low level of removal torque after full osseointegration at 6 weeks supports the feasibility of safe and easy removal of the implant. The HA coating under study appears to offer a unique characteristic of enhanced fixation with a minimal increase in removal torque after full osseointegration. This may be of value in clinical applications where it is necessary to assure both screw fixation and later removal.
文摘Natural biominerals such as bone and teeth show how composite structures can combine organic and inorganic components to achieve both strong mechanical performance and essential biological functions.Inspired by these systems,composite materials are becoming an increasingly important class of biomaterials capable of meeting the growing complexity of biomedical challenges.
基金supported by the National Natural Science Foundation Youth Fund,China(82102582)Natural Science Foundation of Beijing,China(7232119)+2 种基金European Union’s Horizon 2020 research and inno-vation program under the Marie Skłodowska-Curie(812765)Swedish Research Council(2020-04341)Carl TryggersFoundation(CTS 21:1704).
文摘There is a constant need for materials that combine hemostasis and osteogenesis in orthopedic surgery.Current hemostatic materials lack biodegradability,osteogenic properties,and hemostatic efficacy.In this study,we developed a wax-like co-doped polyphosphate(CoPPW)by chelating sodium polyphosphate with cationic ions(Ca^(2+),Mg^(2+),and Sr^(2+)).Our results demonstrate that CoPPW was malleable and degraded optimally,releasing Mg^(2+)and Sr^(2+)ions initially and losing weight over 4 weeks.In vitro,CoPPW promoted better cell proliferation and osteogenic differentiation than beeswax,likely due to ion release.RT-PCR and transcriptome sequencing revealed that CoPPW significantly upregulated osteogenesis-related genes and bone-related protein expression.The activation of the PI3K/AKT signalling pathway confirmed osteogenesis,while the coagulation cascade pathway indicated effective hemostasis.In vivo,CoPPW was more effective in promoting bone regeneration and hemostasis compared to bone wax.Overall,CoPPW exhibits excellent hemostatic and osteogenic effects,making it a promising candidate for bone repair applications.
基金supported by the National Key R&D Program of China(2023YFB3810200,2023YFB3810201)the National Natural Science Foundation of China,China(81925027,32271421)+2 种基金International Cooperation Project of Ningbo City,China(No.2023H013)the Priority Academic Program Development of Jiangsu Higher Education In-stitutions,and Major Special Projects of Science and Technology Plan of Xinjiang Uygur Autonomous Region,China(2022A03011)MJL thanks the Ministry of Science,Technological Development and Innovation of the Republic of Serbia,Serbia(Contract No:451-03-66/2024-03/200017).
文摘Repositioning and securing the cranial bone flap after craniotomy remain significant challenges in neurosurgery.Traditional fixation methods often suffer from weak mechanical strength,bioinertness,limited osteogenic ca-pacity,and a lack of antibacterial properties,complicating clinical outcomes.Recent medical adhesives offer superior fixation but face significant limitations in cranial bone applications.In this study,we explored the application of PAH(Poly(allylamine)hydrochloride)-TPP(Tripolyphosphate)coacervate(PT)as a bone adhe-sive.The PT coacervate demonstrated excellent anti-swelling(anti-swelling ratio less than 1%),self-healing,and injectable properties,as well as exceptional shape adaptability and cytocompatibility.Adhesion tests revealed its outstanding adhesion(99.06±11.76 kPa for lap shear and 121.42±16.73 kPa for end to end),long-term durability,and tunable adhesion strength.Furthermore,the coacervate demonstrated broad-spectrum antibac-terial activity against both Gram-positive and Gram-negative bacteria(antibacterial rate more than 90%),with mechanistic studies revealing promising strategies to address localized and systemic drug-resistant infections.Additionally,the coacervate’s self-mineralizing properties significantly enhanced its osteogenic performance.In vivo studies confirmed its effective fixation,robust antibacterial activity,and improved osteogenesis,under-scoring its suitability for cranial bone flap repositioning and fixation after craniotomy.In summary,this coac-ervate adhesive offers a promising therapeutic solution for addressing the challenges of cranial flap fixation in neurosurgery.
基金supported by a grant from Priority Research Centers Program(2019R1A6A1A11051471)funded by the National Research Foundation of Korea(NRF)and Korea Medical Device Development Fund grant funded by the Korea government(the Ministry of Science and ICT,the Ministry of Trade,Industry and Energy,the Ministry of Health&Welfare and the Ministry of Food and Drug Safety)(Project Number:RS-2020-KD000033)Korea Evaluation Institute of Industrial Technology(KEIT 20018560,NTIS 1415180625)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘The dual role of reactive oxygen and nitrogen species(RONS)in physiological and pathological processes in biological systems has been widely reported.It has been recently suggested that the regulation of RONS levels under physiological and pathological conditions is a potential therapy to promote health and treat diseases,respectively.Injectable hydrogels have been emerging as promising biomaterials for RONS-related biomedical applications owing to their excellent biocompatibility,three-dimensional and extracellular matrix-mimicking structures,tunable properties and easy functionalization.These hydrogels have been developed as advanced injectable platforms for locally generating or scavenging RONS,depending on the specific conditions of the target disease.In this review article,the design principles and mechanism by which RONS are generated/scavenged from hydrogels are outlined alongside a discussion of their in vitro and in vivo evaluations.Additionally,we highlight the advantages and recent developments of these injectable RONS-controlling hydrogels for regenerativemedicines and tissue engineering applications.
