This study introduces a nanostructured MgO coating fabricated via anodization in a non-aqueous electrolyte,offering a novel approach to addressing the challenges of corrosion resistance and biofunctionality.The surfac...This study introduces a nanostructured MgO coating fabricated via anodization in a non-aqueous electrolyte,offering a novel approach to addressing the challenges of corrosion resistance and biofunctionality.The surface was characterized before and after immersion testing using field emission scanning electron microscopy(FESEM),energy-dispersive X-ray spectroscopy(EDX),and X-ray diffraction(XRD).Electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization tests demonstrated a 2-fold reduction in the corrosion resistance compared to untreated magnesium.Biomineralization studies demonstrated the uniform formation of apatite with a Ca/P ratio of 1.35 on the nanostructured surface after 14 days in simulated body fluid(SBF),surpassing that of microstructured MgO.Hydrogen evolution decreased from 912±38μL cm^(-2)for untreated Mg to 615±32μL cm^(-2)for the Mg/MgO nanostructure and 545±29μL cm^(-2)for the Mg/Mg O/HA sample.These findings highlight the potential of nanostructured MgO coatings to advance Mg-based implants by providing enhanced corrosion protection,improved biomineralization,reduced hemolysis and increased cell viability,and reduced H_(2)generation.展开更多
Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinem...Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.展开更多
Titanium and its alloys have been widely applied in many biomedical fields because of its excellent mechanical properties,corrosion resistance and good biocompatibility.However,problems such as rejection,shedding and ...Titanium and its alloys have been widely applied in many biomedical fields because of its excellent mechanical properties,corrosion resistance and good biocompatibility.However,problems such as rejection,shedding and infection will occur after titanium alloy implantation due to the low biological activity of titanium alloy surface.The structures with specific functions,which can enhance osseointegration and antibacterial properties,are fabricated on the surface of titanium implants to improve the biological activity between the titanium implants and human tissues.This paper presents a comprehensive review of recent developments and applications of surface functional structure in titanium and titanium alloy implants.The applications of surface functional structure on different titanium and titanium alloy implants are introduced,and their manufacturing technologies are summarized and compared.Furthermore,the fabrication of various surface functional structures used for titanium and titanium alloy implants is reviewed and analyzed in detail.Finally,the challenges affecting the development of surface functional structures applied in titanium and titanium alloy implants are outlined,and recommendations for future research are presented.展开更多
In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessme...In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.展开更多
Ta-based materials have gained significant interest for bioimplantable scaffolds because of their appropriate mechanical characteristics and biocompatibility.To overcome the serious limitation of bioinertness,there ha...Ta-based materials have gained significant interest for bioimplantable scaffolds because of their appropriate mechanical characteristics and biocompatibility.To overcome the serious limitation of bioinertness,there have been many efforts to enhance the bioactivity and osseointegration of Ta-based scaffolds through morphostructural and surface modifications.As scaffolds are implantable devices,sufficient bioactivity is needed to trigger the cellular functions required for tissue engineering.Consequently,a combination of materials and bioscience is needed to develop efficient Ta-based scaffolds,although reviews of this interdisciplinary field remain limited.This review aims to provide an overview of the main strategies to enhance the bioactivity of Ta-based scaffolds,describing the basic mechanisms and research methods of osseointegration,and the approaches to enhance bioactivity and osseointegration.These approaches are divided into three main sections:(i)alteration of the micromorphology,(ii)customization of the scaffold structure,and(iii)functionalization modifications(through alloying or the addition of surface coatings).Also provided are recent advances regarding biocompatibility assessment in vitro,osseointegration properties in vivo,and clinical trial results.展开更多
The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on...The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium alloy.The obtained coatings demonstrate in vivo biocompatibility and in vitro bioactivity.Compared to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the coatings.It was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in vivo.Based on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen evolution.The results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.展开更多
Surface modification of medical implants was considered as an effective method to improve the cellular behaviors and the integration of tissue onto materials. The micro-nanostructured surface on the titanium alloy was...Surface modification of medical implants was considered as an effective method to improve the cellular behaviors and the integration of tissue onto materials. The micro-nanostructured surface on the titanium alloy was prepared by laser treatment and multiple acid etching. The surface morphologies of different titanium alloy substrates were characterized by scanning electron microscopy (SEM). The effects of micro-nanostructured surfaces on the cellular responses were investigated in vitro by observing hydroxyapatite formation, cell morphology and cell adhesion. The results indicate that the micro-sized structure promoted the adhesion and proliferation of cultured osteoblasts. Furthermore, the micro-nanostructured surface was more conducive to cell adhension stretching compared with the micro-structured surface. All results suggest that the micro-nanostructured surface improved the biocompatibility and integration of tissue onto titanium alloy implants.展开更多
The generation of chemically engineered essential oils(CEEOs)prepared from bi-heteroatomic reactions using ammonium thiocyanate as a source of bioactive compounds is described.The impact of the reaction on the chemica...The generation of chemically engineered essential oils(CEEOs)prepared from bi-heteroatomic reactions using ammonium thiocyanate as a source of bioactive compounds is described.The impact of the reaction on the chemical composition of the mixtures was qualitatively demonstrated through GC-MS,utilizing univariate and multivariate analysis.The reaction transformed most of the components in the natural mixtures,thereby expanding the chemical diversity of the mixtures.Changes in inhibition properties between natural and CEEOs were demonstrated through acetylcholinesterase TLC autography,resulting in a threefold increase in the number of positive events due to the modification process.The chemically engineered Origanum vulgare L.essential oil was subjected to bioguided fractionation,leading to the discovery of four new active compounds with similar or higher potency than eserine against the enzyme.The results suggest that the directed chemical transformation of essential oils can be a valuable strategy for discovering new acetylcholinesterase(AChE)inhibitors.展开更多
In order to develop a new plant-source insecticide,some active components from Cichorium intybus L.were extracted with mineral ether,ethyl ether,ethyl acetate,respectively.It were testified the effects of the componen...In order to develop a new plant-source insecticide,some active components from Cichorium intybus L.were extracted with mineral ether,ethyl ether,ethyl acetate,respectively.It were testified the effects of the components on the development of Mythimna separate Walker and anti-feeding by feeding and weighting method.The results showed that the body weight of the larvae fed by the extracts with organic solvents was significantly lower than the control;the body weight of the larvae fed by the extracts with organic solvents was significantly different in different solvents in 3-5 days.The corrected mortality of the ethyl acetate treatment was the highest（52.05%）,and the development period of the larvae treated by ethyl acetate was about 4-10 days longer than the control and the corresponding pupating rate was the lowest（43.30%）.Therefore,the effect of ethyl acetate extract was most significant.Moreover,the pupa weight of the treatments was little more than the control.The extracts from Cichorium intybus L.leaves had highest bioactivity mainly in anti-feeding activity on Mythimna separate Walker.展开更多
Preparation of Fe^2＋ chelate of fish protein hydrolysate （Fe-FPH） obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate...Preparation of Fe^2＋ chelate of fish protein hydrolysate （Fe-FPH） obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate chelating Fe^2＋ are DH （degree of hydrolysis） at 5%, pH 7.0, 20℃ and 15 min chelating time for FM （material not being defatted）. Four types of Fe-FPH including CA （deposit after chelating）, CB （deposit in 50% of absolute ethanol solution）, CC （suspended deposit in 80% of absolute ethanol solution）, and CD （bottom deposit in 80% of absolute ethanol solution） were fractionated with absolute ethanol from FM. Structural analysis through infra-red spectrum revealed that Fe^2＋ was combined strongly with amino-group and carboxyl-group in each chelate and each Fe^2＋ could form two five-member ring structures. All of the four chelates were shown more significant antioxidative activity and can be used as natural hydrophobic and hydrophilic antioxidant. Among all the chelates, the CB possesses the most effective antioxidative activity at 92% as high as that of a-tocopherol. Among all Fe-FPHs, only CD showed the most effective antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis and can be used as natural antibacterial. It provides a more effective way for utilization of low value fish proteins and key information of Fe-FPH as additive in food industry.展开更多
Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite（Ag-Zeo-HAp） coat...Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite（Ag-Zeo-HAp） coating was synthesized on Ti O2-coated Mg alloy by physical vapour deposition（PVD） assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction（XRD） analysis and field emission scanning electron microscopy（FE-SEM） images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the Ti O2 film with a thickness of 1 μm. The potentiodynamic polarization（PDP） and electrochemical impedance spectroscopy（EIS） tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid（SBF） solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone（3.86 mm） towards Escherichia coli（E. coli） compared with the Ti O2-coated Mg alloy（2.61 mm）. The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.展开更多
The work aims to characterize the structure and to evaluate in vitro the effect of different surface treatments on the bioactivity of medical grade Ti6Al7 Nb alloy implants manufactured by selective laser melting. In ...The work aims to characterize the structure and to evaluate in vitro the effect of different surface treatments on the bioactivity of medical grade Ti6Al7 Nb alloy implants manufactured by selective laser melting. In order to improve the bioactivity of these samples, they were subjected to heat treatment,chemical treatment, and impregnation with bioactive materials. To evaluate the apatite forming ability, the samples were immersed in simulated body fluid solution) and characterized before and after immersion by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy.The composition and the texture of the surfaces after the applied treatments have a selective effect on apatite layer development on the surface of samples.展开更多
Cephalotaxus is the only genus of Cephalotaxaceae family,and its natural resources are declining due to habitat fragmentation,excessive exploitation and destruction.In many areas of China,folk herbal doctors tradition...Cephalotaxus is the only genus of Cephalotaxaceae family,and its natural resources are declining due to habitat fragmentation,excessive exploitation and destruction.In many areas of China,folk herbal doctors traditionally use Cephalotaxus plants to treat innominate swollen poison,many of which are cancer.Not only among Han people,but also among minority ethnic groups,Cephalotaxus is used to treat various diseases,e.g.,cough,internal bleeding and cancer in Miao medicine,bruises,rheumatism and pain in Yao medicine,and ascariasis,hookworm disease,scrofula in She medicine,etc.Medicinal values of some Cephalotaxus species and compounds are acknowledged officially.However,there is a lack of comprehensive review summarizing the ethnomedicinal knowledge o f Cephalotaxus,relevant medicinal phytometabolites and their bioactivities.The research progresses in ethnopharmacology,chemodiversity,and bioactivities of Cephalotaxus medicinal plants are reviewed and commented here.Knowledge gaps are pinpointed and future research directions are suggested.Classic medicinal books,folk medicine books,herbal manuals and ethnomedicinal publications were reviewed for the genus Cephalotaxus(Sanjianshan in Chinese).The relevant data about ethnobotany,phytochemistry,and pharmacology were collected as comprehensively as possible from online databases including Scopus,NCBI PubMed,Bing Scholar,and China National Knowledge Infrastructure(CNKI).44 Cephalotaxus"',and the respective species name were used as keywords in database search.The obtained articles of the past six decades were collated and analyzed.Four Cephalotaxus species are listed in the official medicinal book in China.They are used as ethnomedicines by many ethnic groups such as Miao,Yao,Dong,She and Han.Inspirations are obtained from traditional applications,and Cephalotaxus phytometabolites are developed into anticancer reagents.Cephalotaxine-type alkaloids,homoerythrina-type alkaloids and homoharringtonine(HHT)are abundant in Cephalotaxus,e.g.,C.lanceolata,C.fortunei var.alpina,C.griffithii,and C.hainanensis,etc.New methods of alkaloid analysis and purification are continuously developed and applied.Diterpenoids,sesquiterpenoids,flavonoids,lignans,phenolics,and other components are also identified and isolated in various Cephalotaxus species.Alkaloids such as HHT,terpenoids and other compounds have anticancer activities against multiple types of human cancer.Cephalotaxus extracts and compounds showed anti-inflammatory and antioxidant activities,immunomodulatory activity,antimicrobial activity and nematotoxicity,antihyperglycemic effect,and bone effect,etc.Drug metabolism and pharmacokinetic studies o f Cephalotaxus are increasing.We should continue to collect and sort out folk medicinal knowledge of Cephalotaxus and associated organisms,so as to obtain new enlightenment to translate traditional tips into great therapeutic drugs.Transcriptomics,genomics,metabolomics and proteomics studies can contribute massive information for bioactivity and phytochemistry of Cephalotaxus medicinal plants.We should continue to strengthen the application of state-of-the-art technologies in more Cephalotaxus species and for more useful compounds and pharmacological activities.展开更多
It is well established that various mental stress conditions contribute, or at least influence, underlying pathophysiological mechanisms in somatic, as well as in psychiatric disorders; blood platelets are supposed to...It is well established that various mental stress conditions contribute, or at least influence, underlying pathophysiological mechanisms in somatic, as well as in psychiatric disorders; blood platelets are supposed to represent a possible link in this respect. The anculeated platelets are the smallest corpuscular elements circulating in the human blood. They display different serotonergic markers which seem to reflect the central nervous serotonin metabolism. They are known as main effectors in haematological processes but recent research highlights their role in the innate and adaptive immune system. Platelets are containing a multitude of pro-inflammatory and immune-modulatory bioactive compounds in their granules and are expressing immune-competent surface markers. Research gives hint that platelets activation and reactivity is increased by mental stress. This leads to enhanced cross talk with the immune system via paracrine secretion, receptor interaction and formation of platelet leucocyteaggregates. Recently it has been demonstrated that the immune system can have a remarkable impact in the development of psychiatric disorders. Thereforeplatelets represent an interesting research area in psychiatry and their role as a possible biomarker has been investigated. We review the influence of mental stress on what is termed platelet bioactivity in this article, which subsumes the mainly immune-modulatory activity of platelets in healthy volunteers, elderly persons with chronic care-giving strain, patients with cardiovascular diseases who are prone to psychosocial stress, as well as in patients with posttraumatic stress disorder. Research data suggest that stress enhances platelet activity, reactivity and immune-modulatory capacities.展开更多
Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis o...Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPM alpha FP)(2)en(NO3)(2)]NO3(RE = La, Pr, Nd, Sm, Eu, Th, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, H-1 NMR, C-13 NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E. carotovora, C. flaccumfaciens.展开更多
The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte cont...The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte containing calcium and phosphate,a hydrothermal treatment enabled secondary microporous hydroxyapatite(HA)coating,and a further bone morphogenetic protein-2(BMP-2)loading treatment through immersion and freeze-drying.The treatment led to an orderly secondary microporous coating containing HA nano-particles and evenly distributed BMP-2 in the porous coatings.As a result,osteoblasts could adhere and grow well on the coatings with a high cell adhesion rate and cell functional activity.The in-situ shear testing indicated that the interfacial strength had been enhanced significantly.Improvement of the bond formation and osseointegration with the titanium implant is attributed to increased surface area for the cell to attach,creating voids for the cell to grow in,and activating titanium surface by introducing bioactive ingredients such as HA and BMP-2.展开更多
Amelogenin（AMG） is a cell adhesion molecule that has an important role in the mineralization of enamel and regulates events during dental development and root formation. The purpose of the present study was to inves...Amelogenin（AMG） is a cell adhesion molecule that has an important role in the mineralization of enamel and regulates events during dental development and root formation. The purpose of the present study was to investigate the effects of recombinant human AMG（rhAMG） on mineralized tissue-associated genes in cementoblasts. Immortalized mouse cementoblasts（OCCM-30）were treated with different concentrations（0.1, 1, 10, 100, 1 000, 10 000, 100 000 ng · mL^-1） of recombinant human AMG（rhAMG）and analyzed for proliferation, mineralization and mRNA expression of bone sialoprotein（BSP）, osteocalcin（OCN）, collagen type I（COL I）, osteopontin（OPN）, runt-related transcription factor 2（Runx2）, cementum attachment protein（CAP）, and alkaline phosphatase（ALP） genes using quantitative RT-PCR. The dose response of rhAMG was evaluated using a real-time cell analyzer.Total RNA was isolated on day 3, and cell mineralization was assessed using von Kossa staining on day 8. COL I, OPN and lysosomalassociated membrane protein-1（LAMP-1）, which is a cell surface binding site for amelogenin, were evaluated using immunocytochemistry. F-actin bundles were imaged using confocal microscopy. rhAMG at a concentration of 100 000 ng · mL^-1 increased cell proliferation after 72 h compared to the other concentrations and the untreated control group. rhAMG（100 000 ng · mL^-1） upregulated BSP and OCN mRNA expression levels eightfold and fivefold, respectively. rhAMG at a concentration of 100 000 ng · mL^-1 remarkably enhanced LAMP-1 staining in cementoblasts. Increased numbers of mineralized nodules were observed at concentrations of 10 000 and 100 000 ng · mL^-1 rhAMG. The present data suggest that rhAMG is a potent regulator of gene expression in cementoblasts and support the potential application of rhAMG in therapies aimed at fast regeneration of damaged periodontal tissue.展开更多
Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits wi...Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.展开更多
Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of tita...Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V（TC4） surface with calcium phosphate （Ca-P） bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth （RE）, on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, thermogravimetric analysis and Different-thermal Scanning （TG-DSC）, and Energy Dispersive X-ray Detection （EDX）. The results show that these laser ceramics include hydroxyapatite （HA）, tricalcium phosphate （TCP）, Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.展开更多
Objective:To isolate and characterize antidiabetic component（bioactivity-guided fractionation） from hydro alcoholic extract of Ocimum sanctum（O.sanctum） aerial part.Methods:Ten fractions（F1 - F10） were isolated ...Objective:To isolate and characterize antidiabetic component（bioactivity-guided fractionation） from hydro alcoholic extract of Ocimum sanctum（O.sanctum） aerial part.Methods:Ten fractions（F1 - F10） were isolated from hydro alcoholic extract of O.sanctum aerial part by column chromatography.All the fractions Fl to F10 were screened for antidiabetic activity in alloxan induced diabetic rats by estimating serum glucose level and lipid parameters.The isolated bioactive component was elucidated on the basis of extensive spectroscopic(UV,IR,MS,<sup>1</sup>H and <sup>13</sup>C NMR) data analysis.Results:The bioactive fraction（F5） was found to be potent antidiabetic by ameliorating glucose and lipid parameters（total cholesterol,triglycerides,low and high density lipoprotein cholesterol）.The extensive spectroscopic data analysis reveals that,the isolated bioactive compound elucidated as tetracyclic triterpenoid[16-Hydroxy-4,4,10,13-tetramethyl- 17-（4-methyI-pentyl）-hexadecahydro-cyclopenta[a]phenanthren-3-one].Conclusions:Our present study concluded that,tetracyclic triterpenoid isolated from aerial part of O.sanctum has a great anti-diabetic potential.展开更多
基金The authors thank the DFG(KI 2169/2-1)the European Union(EU-RIA NOMAD,101091669)for funding this work+1 种基金The Micro and Nanoanalytics Facility(MNaF),funded by the DFG(DFG INST 221/131-1)at the University of Siegen,and the Materials Science Faculty of the Isfahan University of Technology(IUT)were utilized for some of the work and analysis,respectively.
文摘This study introduces a nanostructured MgO coating fabricated via anodization in a non-aqueous electrolyte,offering a novel approach to addressing the challenges of corrosion resistance and biofunctionality.The surface was characterized before and after immersion testing using field emission scanning electron microscopy(FESEM),energy-dispersive X-ray spectroscopy(EDX),and X-ray diffraction(XRD).Electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization tests demonstrated a 2-fold reduction in the corrosion resistance compared to untreated magnesium.Biomineralization studies demonstrated the uniform formation of apatite with a Ca/P ratio of 1.35 on the nanostructured surface after 14 days in simulated body fluid(SBF),surpassing that of microstructured MgO.Hydrogen evolution decreased from 912±38μL cm^(-2)for untreated Mg to 615±32μL cm^(-2)for the Mg/MgO nanostructure and 545±29μL cm^(-2)for the Mg/Mg O/HA sample.These findings highlight the potential of nanostructured MgO coatings to advance Mg-based implants by providing enhanced corrosion protection,improved biomineralization,reduced hemolysis and increased cell viability,and reduced H_(2)generation.
基金supported by the University Malaya(Grant code:FRGS/1/2022/TK10/UM/02/6)the National Natural Science Foundation of China(Grant No.51275414,No.51605387)Deanship of Scientific Research at King Khalid University for funding this work through the Large Groups Project under grant number RGP.2/303/44。
文摘Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.
基金Supported by National Natural Science Foundation of China (Grant Nos.52235011,51905352)Shenzhen Municipal Excellent Science and Technology Creative Talent Training Program (Grant No.RCBS20210609103819021)+1 种基金Guangdong Provincial Basic and Applied Basic Research Foundation (Grant No.2023B1515120086)Shenzhen Municipal Science and Technology Planning Project (Grant No.CJGJZD20230724093600001)。
文摘Titanium and its alloys have been widely applied in many biomedical fields because of its excellent mechanical properties,corrosion resistance and good biocompatibility.However,problems such as rejection,shedding and infection will occur after titanium alloy implantation due to the low biological activity of titanium alloy surface.The structures with specific functions,which can enhance osseointegration and antibacterial properties,are fabricated on the surface of titanium implants to improve the biological activity between the titanium implants and human tissues.This paper presents a comprehensive review of recent developments and applications of surface functional structure in titanium and titanium alloy implants.The applications of surface functional structure on different titanium and titanium alloy implants are introduced,and their manufacturing technologies are summarized and compared.Furthermore,the fabrication of various surface functional structures used for titanium and titanium alloy implants is reviewed and analyzed in detail.Finally,the challenges affecting the development of surface functional structures applied in titanium and titanium alloy implants are outlined,and recommendations for future research are presented.
文摘In this study,Mg-based composites,by the addition of ZnO,Ca_(2)ZnSi_(2)O_(7),Ca_(2)MgSi_(2)O_(7),and CaSiO_(3)as bioactive agents,were fabricated using friction stir processing.The microstructure and in vitro assessment of bioactivity,biodegradation rate,and corrosion behavior of the resultant composites were investigated in simulated body fluid(SBF).The results showed that during the immersion of composites in SBF for 28 d,due to the release of Ca^(2+)and PO_(4)^(3-)ions,hydroxyapatite(HA)crystals with cauliflower shaped morphology were deposited on the surface of composites,confirming good bioactivity of composites.In addition,due to the uniform distribution of bioceramic powders throughout Mg matrix,grain refinement of the Mg matrix,and uniform redistribution of secondary phase particles,the polarization resistance increased,and the biodegradation rate of composites significantly reduced compared to monolithic Mg matrix.The polarization corrosion resistance of Mg-ZnO increased from 0.216 to 2.499 kΩ/cm^(2)compared to monolithic Mg alloy.Additionally,Mg-ZnO composite with the weight loss of 0.0217 g after 28 d immersion showed lower weight loss compared to other samples with increasing immersion time.Moreover,Mg-ZnO composite with the biodegradation rate of 37.71 mm/a exhibited lower biodegradation rate compared to other samples with increasing immersion time.
基金Financially Natural Science Foundation of Shandong Province(No.ZR2023ME181)。
文摘Ta-based materials have gained significant interest for bioimplantable scaffolds because of their appropriate mechanical characteristics and biocompatibility.To overcome the serious limitation of bioinertness,there have been many efforts to enhance the bioactivity and osseointegration of Ta-based scaffolds through morphostructural and surface modifications.As scaffolds are implantable devices,sufficient bioactivity is needed to trigger the cellular functions required for tissue engineering.Consequently,a combination of materials and bioscience is needed to develop efficient Ta-based scaffolds,although reviews of this interdisciplinary field remain limited.This review aims to provide an overview of the main strategies to enhance the bioactivity of Ta-based scaffolds,describing the basic mechanisms and research methods of osseointegration,and the approaches to enhance bioactivity and osseointegration.These approaches are divided into three main sections:(i)alteration of the micromorphology,(ii)customization of the scaffold structure,and(iii)functionalization modifications(through alloying or the addition of surface coatings).Also provided are recent advances regarding biocompatibility assessment in vitro,osseointegration properties in vivo,and clinical trial results.
基金The formation of coatings,as well as SEM,EDS,FTIR spectroscopy and mechanical studies was supported by Russian Science Foundation grant No.22-73-10149,https://rscf.ru/project/22-73-10149/The electrochemical studies,in vitro and in vivo studies was supported by the Russian Science Foundation grant No.23-13-00329,https://rscf.ru/project/23-13-00329/。
文摘The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium alloy.The obtained coatings demonstrate in vivo biocompatibility and in vitro bioactivity.Compared to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the coatings.It was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in vivo.Based on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen evolution.The results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.
基金Projects(5117530651575320)supported by the National Natural Science Foundation of China+1 种基金Project(TS20130922)supported by the Taishan Scholar Foundation,ChinaProject(2014JC020)supported by the Fundamental Research Funds for the Central Universities of China
文摘Surface modification of medical implants was considered as an effective method to improve the cellular behaviors and the integration of tissue onto materials. The micro-nanostructured surface on the titanium alloy was prepared by laser treatment and multiple acid etching. The surface morphologies of different titanium alloy substrates were characterized by scanning electron microscopy (SEM). The effects of micro-nanostructured surfaces on the cellular responses were investigated in vitro by observing hydroxyapatite formation, cell morphology and cell adhesion. The results indicate that the micro-sized structure promoted the adhesion and proliferation of cultured osteoblasts. Furthermore, the micro-nanostructured surface was more conducive to cell adhension stretching compared with the micro-structured surface. All results suggest that the micro-nanostructured surface improved the biocompatibility and integration of tissue onto titanium alloy implants.
基金support by Universidad Nacional de Rosario(80020180300114UR and 80020180100128UR)CONICET(PIP No 11220200102423)and FONCYT(PICT2015-3574 and PICT2018-01554)for the development of this work.
文摘The generation of chemically engineered essential oils(CEEOs)prepared from bi-heteroatomic reactions using ammonium thiocyanate as a source of bioactive compounds is described.The impact of the reaction on the chemical composition of the mixtures was qualitatively demonstrated through GC-MS,utilizing univariate and multivariate analysis.The reaction transformed most of the components in the natural mixtures,thereby expanding the chemical diversity of the mixtures.Changes in inhibition properties between natural and CEEOs were demonstrated through acetylcholinesterase TLC autography,resulting in a threefold increase in the number of positive events due to the modification process.The chemically engineered Origanum vulgare L.essential oil was subjected to bioguided fractionation,leading to the discovery of four new active compounds with similar or higher potency than eserine against the enzyme.The results suggest that the directed chemical transformation of essential oils can be a valuable strategy for discovering new acetylcholinesterase(AChE)inhibitors.
基金Supported by International Cooperation Project from Ministry of Science and Technology"Cooperation Research of Chicory Natural Production Extraction and Identification"(2008DFA31650)Shaanxi International Cooperation Project"Cooperation Research of Chicory Natural Production Extraction and Identification"(2008KW-29)~~
文摘In order to develop a new plant-source insecticide,some active components from Cichorium intybus L.were extracted with mineral ether,ethyl ether,ethyl acetate,respectively.It were testified the effects of the components on the development of Mythimna separate Walker and anti-feeding by feeding and weighting method.The results showed that the body weight of the larvae fed by the extracts with organic solvents was significantly lower than the control;the body weight of the larvae fed by the extracts with organic solvents was significantly different in different solvents in 3-5 days.The corrected mortality of the ethyl acetate treatment was the highest（52.05%）,and the development period of the larvae treated by ethyl acetate was about 4-10 days longer than the control and the corresponding pupating rate was the lowest（43.30%）.Therefore,the effect of ethyl acetate extract was most significant.Moreover,the pupa weight of the treatments was little more than the control.The extracts from Cichorium intybus L.leaves had highest bioactivity mainly in anti-feeding activity on Mythimna separate Walker.
基金Supported by National Natural Science Foundation of China (No.30371123)Science and Technology Department of Zhejiang Province (No. 2007C12013)
文摘Preparation of Fe^2＋ chelate of fish protein hydrolysate （Fe-FPH） obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate chelating Fe^2＋ are DH （degree of hydrolysis） at 5%, pH 7.0, 20℃ and 15 min chelating time for FM （material not being defatted）. Four types of Fe-FPH including CA （deposit after chelating）, CB （deposit in 50% of absolute ethanol solution）, CC （suspended deposit in 80% of absolute ethanol solution）, and CD （bottom deposit in 80% of absolute ethanol solution） were fractionated with absolute ethanol from FM. Structural analysis through infra-red spectrum revealed that Fe^2＋ was combined strongly with amino-group and carboxyl-group in each chelate and each Fe^2＋ could form two five-member ring structures. All of the four chelates were shown more significant antioxidative activity and can be used as natural hydrophobic and hydrophilic antioxidant. Among all the chelates, the CB possesses the most effective antioxidative activity at 92% as high as that of a-tocopherol. Among all Fe-FPHs, only CD showed the most effective antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis and can be used as natural antibacterial. It provides a more effective way for utilization of low value fish proteins and key information of Fe-FPH as additive in food industry.
文摘Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite（Ag-Zeo-HAp） coating was synthesized on Ti O2-coated Mg alloy by physical vapour deposition（PVD） assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction（XRD） analysis and field emission scanning electron microscopy（FE-SEM） images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the Ti O2 film with a thickness of 1 μm. The potentiodynamic polarization（PDP） and electrochemical impedance spectroscopy（EIS） tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid（SBF） solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone（3.86 mm） towards Escherichia coli（E. coli） compared with the Ti O2-coated Mg alloy（2.61 mm）. The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.
文摘The work aims to characterize the structure and to evaluate in vitro the effect of different surface treatments on the bioactivity of medical grade Ti6Al7 Nb alloy implants manufactured by selective laser melting. In order to improve the bioactivity of these samples, they were subjected to heat treatment,chemical treatment, and impregnation with bioactive materials. To evaluate the apatite forming ability, the samples were immersed in simulated body fluid solution) and characterized before and after immersion by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy.The composition and the texture of the surfaces after the applied treatments have a selective effect on apatite layer development on the surface of samples.
基金the Scientific Research Funds Project of Liaoning Education Department(JDL2019012)Natural Science Fund of Liaoning Province(20180550190).
文摘Cephalotaxus is the only genus of Cephalotaxaceae family,and its natural resources are declining due to habitat fragmentation,excessive exploitation and destruction.In many areas of China,folk herbal doctors traditionally use Cephalotaxus plants to treat innominate swollen poison,many of which are cancer.Not only among Han people,but also among minority ethnic groups,Cephalotaxus is used to treat various diseases,e.g.,cough,internal bleeding and cancer in Miao medicine,bruises,rheumatism and pain in Yao medicine,and ascariasis,hookworm disease,scrofula in She medicine,etc.Medicinal values of some Cephalotaxus species and compounds are acknowledged officially.However,there is a lack of comprehensive review summarizing the ethnomedicinal knowledge o f Cephalotaxus,relevant medicinal phytometabolites and their bioactivities.The research progresses in ethnopharmacology,chemodiversity,and bioactivities of Cephalotaxus medicinal plants are reviewed and commented here.Knowledge gaps are pinpointed and future research directions are suggested.Classic medicinal books,folk medicine books,herbal manuals and ethnomedicinal publications were reviewed for the genus Cephalotaxus(Sanjianshan in Chinese).The relevant data about ethnobotany,phytochemistry,and pharmacology were collected as comprehensively as possible from online databases including Scopus,NCBI PubMed,Bing Scholar,and China National Knowledge Infrastructure(CNKI).44 Cephalotaxus"',and the respective species name were used as keywords in database search.The obtained articles of the past six decades were collated and analyzed.Four Cephalotaxus species are listed in the official medicinal book in China.They are used as ethnomedicines by many ethnic groups such as Miao,Yao,Dong,She and Han.Inspirations are obtained from traditional applications,and Cephalotaxus phytometabolites are developed into anticancer reagents.Cephalotaxine-type alkaloids,homoerythrina-type alkaloids and homoharringtonine(HHT)are abundant in Cephalotaxus,e.g.,C.lanceolata,C.fortunei var.alpina,C.griffithii,and C.hainanensis,etc.New methods of alkaloid analysis and purification are continuously developed and applied.Diterpenoids,sesquiterpenoids,flavonoids,lignans,phenolics,and other components are also identified and isolated in various Cephalotaxus species.Alkaloids such as HHT,terpenoids and other compounds have anticancer activities against multiple types of human cancer.Cephalotaxus extracts and compounds showed anti-inflammatory and antioxidant activities,immunomodulatory activity,antimicrobial activity and nematotoxicity,antihyperglycemic effect,and bone effect,etc.Drug metabolism and pharmacokinetic studies o f Cephalotaxus are increasing.We should continue to collect and sort out folk medicinal knowledge of Cephalotaxus and associated organisms,so as to obtain new enlightenment to translate traditional tips into great therapeutic drugs.Transcriptomics,genomics,metabolomics and proteomics studies can contribute massive information for bioactivity and phytochemistry of Cephalotaxus medicinal plants.We should continue to strengthen the application of state-of-the-art technologies in more Cephalotaxus species and for more useful compounds and pharmacological activities.
文摘It is well established that various mental stress conditions contribute, or at least influence, underlying pathophysiological mechanisms in somatic, as well as in psychiatric disorders; blood platelets are supposed to represent a possible link in this respect. The anculeated platelets are the smallest corpuscular elements circulating in the human blood. They display different serotonergic markers which seem to reflect the central nervous serotonin metabolism. They are known as main effectors in haematological processes but recent research highlights their role in the innate and adaptive immune system. Platelets are containing a multitude of pro-inflammatory and immune-modulatory bioactive compounds in their granules and are expressing immune-competent surface markers. Research gives hint that platelets activation and reactivity is increased by mental stress. This leads to enhanced cross talk with the immune system via paracrine secretion, receptor interaction and formation of platelet leucocyteaggregates. Recently it has been demonstrated that the immune system can have a remarkable impact in the development of psychiatric disorders. Thereforeplatelets represent an interesting research area in psychiatry and their role as a possible biomarker has been investigated. We review the influence of mental stress on what is termed platelet bioactivity in this article, which subsumes the mainly immune-modulatory activity of platelets in healthy volunteers, elderly persons with chronic care-giving strain, patients with cardiovascular diseases who are prone to psychosocial stress, as well as in patients with posttraumatic stress disorder. Research data suggest that stress enhances platelet activity, reactivity and immune-modulatory capacities.
文摘Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPM alpha FP)(2)en(NO3)(2)]NO3(RE = La, Pr, Nd, Sm, Eu, Th, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, H-1 NMR, C-13 NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E. carotovora, C. flaccumfaciens.
基金financial support of the National Natural Science Foundation of China(32071327)National Key Research and Development Program of China(2016YFC1102003)+2 种基金International Science and Technology Cooperation Base of Shaanxi Province(2017GHJD-014)Science and Technology Program of Shaanxi Province(2019GY-200)Key Research and Development Program of Shaanxi Province(2019ZDLSF03-06)。
文摘The gradient porous Ti3Zr2Sn3Mo25Nb(TLM)alloy rods were fabricated through sintering the alloyed powder to a solid core.The porous sample was then modified by a Micro Arc Oxidation(MAO)treatment in an electrolyte containing calcium and phosphate,a hydrothermal treatment enabled secondary microporous hydroxyapatite(HA)coating,and a further bone morphogenetic protein-2(BMP-2)loading treatment through immersion and freeze-drying.The treatment led to an orderly secondary microporous coating containing HA nano-particles and evenly distributed BMP-2 in the porous coatings.As a result,osteoblasts could adhere and grow well on the coatings with a high cell adhesion rate and cell functional activity.The in-situ shear testing indicated that the interfacial strength had been enhanced significantly.Improvement of the bond formation and osseointegration with the titanium implant is attributed to increased surface area for the cell to attach,creating voids for the cell to grow in,and activating titanium surface by introducing bioactive ingredients such as HA and BMP-2.
基金supported by TüBITAK SBAG108S265(Turkey)BMBF TUR08/09(Germany)
文摘Amelogenin（AMG） is a cell adhesion molecule that has an important role in the mineralization of enamel and regulates events during dental development and root formation. The purpose of the present study was to investigate the effects of recombinant human AMG（rhAMG） on mineralized tissue-associated genes in cementoblasts. Immortalized mouse cementoblasts（OCCM-30）were treated with different concentrations（0.1, 1, 10, 100, 1 000, 10 000, 100 000 ng · mL^-1） of recombinant human AMG（rhAMG）and analyzed for proliferation, mineralization and mRNA expression of bone sialoprotein（BSP）, osteocalcin（OCN）, collagen type I（COL I）, osteopontin（OPN）, runt-related transcription factor 2（Runx2）, cementum attachment protein（CAP）, and alkaline phosphatase（ALP） genes using quantitative RT-PCR. The dose response of rhAMG was evaluated using a real-time cell analyzer.Total RNA was isolated on day 3, and cell mineralization was assessed using von Kossa staining on day 8. COL I, OPN and lysosomalassociated membrane protein-1（LAMP-1）, which is a cell surface binding site for amelogenin, were evaluated using immunocytochemistry. F-actin bundles were imaged using confocal microscopy. rhAMG at a concentration of 100 000 ng · mL^-1 increased cell proliferation after 72 h compared to the other concentrations and the untreated control group. rhAMG（100 000 ng · mL^-1） upregulated BSP and OCN mRNA expression levels eightfold and fivefold, respectively. rhAMG at a concentration of 100 000 ng · mL^-1 remarkably enhanced LAMP-1 staining in cementoblasts. Increased numbers of mineralized nodules were observed at concentrations of 10 000 and 100 000 ng · mL^-1 rhAMG. The present data suggest that rhAMG is a potent regulator of gene expression in cementoblasts and support the potential application of rhAMG in therapies aimed at fast regeneration of damaged periodontal tissue.
基金This project was supported by the National Scientific Committee(969202011), the Natural Science Foundation of Hubei Province(99J
文摘Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.
基金Item Sponsored by National Natural Science Foundation of China(59571045)
文摘Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V（TC4） surface with calcium phosphate （Ca-P） bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth （RE）, on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, thermogravimetric analysis and Different-thermal Scanning （TG-DSC）, and Energy Dispersive X-ray Detection （EDX）. The results show that these laser ceramics include hydroxyapatite （HA）, tricalcium phosphate （TCP）, Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.
文摘Objective:To isolate and characterize antidiabetic component（bioactivity-guided fractionation） from hydro alcoholic extract of Ocimum sanctum（O.sanctum） aerial part.Methods:Ten fractions（F1 - F10） were isolated from hydro alcoholic extract of O.sanctum aerial part by column chromatography.All the fractions Fl to F10 were screened for antidiabetic activity in alloxan induced diabetic rats by estimating serum glucose level and lipid parameters.The isolated bioactive component was elucidated on the basis of extensive spectroscopic(UV,IR,MS,<sup>1</sup>H and <sup>13</sup>C NMR) data analysis.Results:The bioactive fraction（F5） was found to be potent antidiabetic by ameliorating glucose and lipid parameters（total cholesterol,triglycerides,low and high density lipoprotein cholesterol）.The extensive spectroscopic data analysis reveals that,the isolated bioactive compound elucidated as tetracyclic triterpenoid[16-Hydroxy-4,4,10,13-tetramethyl- 17-（4-methyI-pentyl）-hexadecahydro-cyclopenta[a]phenanthren-3-one].Conclusions:Our present study concluded that,tetracyclic triterpenoid isolated from aerial part of O.sanctum has a great anti-diabetic potential.
