OBJECTIVE: To investigate the biocompatibility of porous WE43 magnesium alloy scaffolds manufactured by 3D printing technology and to observe its effect in treating femoral defects in New Zealand white rabbits. METHODS: In vitro cytotoxicity test was performed using bone marrow mesenchymal stem cells from Sprague Dawley (S-D) rats. According to the different culture media, the cells were divided into 100% extract group, 50% extract group, 10% extract group and control group. After culturing for 1, 3 and 7 days, the cell activity of each group was determined by cell counting kit-8 (CCK-8). In the in vivo experiment, 3.0-3.5 kg New Zealand white rabbits were randomly divided into three groups: Experimental group, bone cement group and blank group, with 9 rabbits in each group. Each rabbit underwent surgery on the left lateral femoral condyle, and a bone defect with a diameter of 5 mm and a depth of 6 mm was created using a bone drill. The experimental group was implanted with WE43 magnesium alloy scaffolds, the bone cement group was implanted with calcium sulfate bone cement, and the blank group was not implanted. Then 4, 8 and 12 weeks after surgery, 3 rabbits in each group were euthanized by carbon dioxide anesthesia, and the femur and important internal organs were sampled. Micro-computed tomography (Micro-CT) scanning was performed on the left lateral femoral condyle. Sections of important internal organs were prepared and stained with hematoxylin-eosin (HE). Hard tissue sections were made from the left lateral femoral condyle and stained with methylene blue acid fuchsin and observed under a microscope. RESULTS: In the cytotoxicity test, the cell survival rate in the 100% extract group was higher than that in the control group (140.56% vs. 100.00%, P < 0.05) on 1 day of culture; there was no statistically significant difference (P>0.05) in cell survival rate among the groups on 3 days of culture; the cell survival rate in the 100% extract group was lower than that in the control group (68.64% vs. 100.00%, P < 0.05) on 7 days of culture. Micro-CT scanning in the in vivo experiment found that most of the scaffolds in the experimental group had been degraded in 4 weeks, with very few high-density scaffolds remaining. In 12 weeks, there was no obvious stent outline. In 4 weeks, a certain amount of gas was generated around the WE43 magnesium alloy scaffold, and the gas was significantly reduced from 8 to 12 weeks. Hard tissue sections showed that a certain amount of extracellular matrix and osteoid were generated around the scaffolds in the experimental group in 4 weeks. In the bone cement group, most of the calcium sulfate bone cement had been degraded. In 8 weeks, the osteoid around the scaffold and its degradation products in the experimental group increased significantly. In 12 weeks, new bone was in contact with the scaffold around the scaffold in the experimental group. There was less new bone in the bone cement group and the blank group. CONCLUSION The porous WE43 magnesium alloy scaffold fabricated by 3D printing process has good biocompatibility and good osteogenic properties, and has the potential to become a new material for repairing bone defects.
Animals ; Rabbits ; Printing, Three-Dimensional ; Alloys/chemistry* ; Tissue Scaffolds/chemistry* ; Magnesium/chemistry* ; Rats, Sprague-Dawley ; Biocompatible Materials ; Mesenchymal Stem Cells/cytology* ; Femur/surgery* ; Rats ; Absorbable Implants ; Male ; Bone Regeneration ; Tissue Engineering/methods* ; Cells, Cultured

Due to their good properties of elastic modulus, degradability and ability to promote bone repair, magnesium alloys have become a research hotspot in research of orthopedic implants. Nevertheless, most of the biomedical magnesium alloys currently available fail to meet the requirements in orthopedics because of their rapid degradation after implantation. Rare earth-magnesium alloys possess excellent corrosion resistance and are expected to become important materials as clinical orthopedic implants. This review summarizes the recent progress in studies of the physiological functions of rare earth elements, the effects of supplementation of rare earth elements on biomechanical properties and the in vitro and in vivo biocompatibility of magnesium alloys, and their contribution to tendon-bone healing, addressing also the current clinical orthopedic applications of different rare earth-magnesium alloys, challenges, and future strategies for improving these alloys.
Alloys/chemistry* ; Magnesium/chemistry* ; Metals, Rare Earth/chemistry* ; Humans ; Biocompatible Materials ; Prostheses and Implants

Vascular stents are an essential tool in cardiovascular interventional therapy, and their demand is growing with the increasing incidence of cardiovascular diseases. Compared with permanent stents, which are prone to in-stent restenosis, and drug-eluting stents, which may cause late stent thrombosis, biodegradable stents offer advantages. After providing early radial support to prevent elastic recoil, biodegradable stents gradually degrade, allowing the vessel to regain its natural physiological contractility and undergo positive remodeling. A review of the current mainstream biodegradable metal stents, magnesium-based, iron-based, and zinc-based alloys, shows promising findings in both preclinical and clinical research. Magnesium-based stents exhibit good operability and low thrombosis rates, but their limitations include rapid degradation, hydrogen evolution, and significant pH changes in the microenvironment. Iron-based stents demonstrate excellent mechanical strength, formability, biocompatibility, and hemocompatibility, but their slow corrosion rate hampers broader clinical application; accelerating degradation remains key. Zinc-based alloys have a moderate degradation rate but relatively low mechanical strength; enhancing stent strength by alloying with other elements is the main improvement direction for zinc-based stents.
Humans ; Absorbable Implants ; Stents ; Alloys/chemistry* ; Magnesium/chemistry* ; Biocompatible Materials/chemistry* ; Zinc/chemistry* ; Drug-Eluting Stents ; Iron/chemistry* ; Metals/chemistry*

This study aims to investigate the effects of different magnesium supply levels on the growth, nutrient absorption and distribution, and quality of Panax quinquefolium, and to determine the optimum content of exchangeable magnesium in soil. Three-year-old plants of P. quinquefolium were used in this study, and eight magnesium supply gradients(CK, Mg1-Mg7) were designed for indoor pot experiment(cultivation in soil). The plant growth indexes, nutrient element content in soil and plant, and root saponin content were determined at the end of the growth period. The correlation analysis of nutrient element content in aboveground and underground parts of P. quinquefolium showed significantly negative correlations of magnesium-calcium, magnesium-potassium, and magne-sium-manganese. With the increase in magnesium supply level, the biological absorption coefficient of magnesium increased, while that of total nitrogen, potassium, iron, and manganese decreased; the biological transfer coefficient of magnesium decreased, while that of nitrogen, phosphorus, calcium, iron, and manganese increased. The saponin content was analyzed by principal component analysis, which showed the comprehensive score in the order of Mg4(2.537), Mg2(1.001), Mg3(0.600), Mg1(0), Mg7(-0.765), CK(-0.825), Mg6(-0.922), and Mg5(-1.663). The partial least squares-path modeling(PLS-PM) showed that the correlation coefficients of exchangeable magnesium and pH with quality were-0.748 and-0.755, respectively, which were significant. Magnesium-calcium, magnesium-potassium, and magnesium-manganese showed antagonism in the nutritional physiology of P. quinquefolium. Excessive application of magnesium can lead to the imbalance of nutrient elements in P. quinquefolium. The content of exchangeable magnesium in soil suitable for the quality formation of P. quinquefolium was 193.34-293.34 mg·kg~(-1). In addition to exchangeable magnesium, pH was also important to the quality formation of P. quinquefolium. Therefore, exchangeable magnesium and pH could be regarded as monitoring factors for the quality formation of P. quinquefolium.
Magnesium ; Nutrients ; Panax/chemistry* ; Phosphorus ; Soil/chemistry*

Attapulgite(ATP), as a fertilizer slow-release agent and soil conditioner, has shown remarkable effect in improving the utilization rate of fertilizer and the yield and quality of agricultural products and Chinese medicinal materials. This study aims to explore the effect of ATP on the growth and root quality of Angelica sinensis. To be specific, Mingui 1 was used, and through the pot(soil culture) experiment in the Dao-di producing area, the effects of conventional chemical fertilizer added with ATP on the morphology, photosynthesis, soil respiration, and content of ferulic acid and volatile oil in roots of Mingui 1 were detected. The underlying mechanism was discussed from the perspective of source-sink relationship. The results showed that ATP, via the fertilizer slow-release effect, could meet the needs of A. sinensis for nutrients at the root expansion stage, improve the net photosynthetic rate of leaves and aboveground biomass of plants, and promote the transfer and accumulation of nutrients from the aboveground part(source) to the underground root(sink) in advance during the dry matter accumulation period of roots, so as to improve the root weight per plant. ATP can increase the content of total ferulic acid(the sum of free ferulic acid and coniferyl ferulate), the main effective component of Angelicae Sinensis Radix, by promoting the synthesis of ferulic acid in the roots and the transformation to coniferyl ferulate. However, it had little effect on the content of volatile oil. ATP had certain influence on soil respiration, which needs to be further explored from root activity, rhizosphere microorganisms, and soil microorganisms. This study can lay a basis for soil remediation and improvement and ecological cultivation of A. sinensis.
Adenosine Triphosphate ; Angelica sinensis/chemistry* ; Coumaric Acids ; Fertilizers/analysis* ; Magnesium Compounds ; Oils, Volatile/chemistry* ; Plant Roots/chemistry* ; Silicon Compounds ; Soil

A minimal data set( MDS) for soil fertility evaluation of Chrysanthemum plantation areas of Macheng city was established by principal component analysis( PCA) combined with Norm values of soil fertility indices and correlation coefficients among indices. A radar map was used to visually reflect the fertility level of individual indicators. Then,the comprehensive index model was used to calculate the soil fertility quality index( SFQI),and the values of SFQI was used to cluster,and the results showed that MDS was composed of five indicators: organic matter( OM),total phosphate( TP),available phosphorus( Av P),available magnesium( Av Mg) and available ferrum( Av Fe). Radar maps showed that the fertility of available phosphorus( Av P) and available copper( Av Cu) was mostly different in the two town,and the fertility of available ferrum( Av Fe) is smallest different. Except for the effective manganese( Av Mn) fertility level of Huangtugang town was higher than that of Futianhe town,the rest were lower than that of Futianhe town. Through analysis,the sensitivity of SFQI value calculated by taking the contribution rate of MDS index in the principal component of the whole data set( TDS) as the weight was the highest,MDS could better replace TDS. The value of SFQI-MDS ranged from 0. 353 to 0. 833,with an average value of 0. 604 and a coefficient of variation of 22%. The results of SFQI-MDS clustering showed that soil fertility could be divided into four categories: grade Ⅰ( 0. 727-0. 833) was superior,accounting for 25. 0%,grade Ⅱ( 0. 615-0. 681)was good,accounting for 29. 2%,mainly distributed in Futianhe Town,grade Ⅲ( 0. 494-0. 589) was medium,accounting for29. 1%,and grade Ⅳ( 0. 353-0. 419) was poor,accounting for 16. 7%,mainly distributed in Huangtugang town. Soil fertility of Futianhe town was better than that of Huangtugang town. It is suggested that boron fertilizer and potassium fertilizer should be supplemented to Chrysanthemum morifolium in production practice,and the amount of phosphate fertilizer,magnesium fertilizer and nitrogen fertilizer should be increased appropriately. At the same time,the amount of organic fertilizer should be increased to enhance soil fertility and improve soil physical and chemical properties.
China ; Chrysanthemum/growth & development* ; Fertilizers ; Magnesium ; Nitrogen ; Phosphates ; Phosphorus ; Plants, Medicinal/growth & development* ; Soil/chemistry*

BACKGROUND: It is known that the blood collection tube used can cause fluctuations in laboratory test results. We compared test results obtained when blood was collected in V-tube (AB Medical, Korea), BD Vacutainer Tubes (BD, USA), and Greiner Vacuette Tubes (Greiner, USA) in clinical chemistry and thyroid hormone assays. METHODS: One hundred volunteers from three hospitals were recruited and the peripheral blood samples were collected in each of the three serum separation tubes (SSTs). These samples were used for 28 routine clinical chemistry assays and three thyroid hormone assays. The results were analyzed by the Student paired t-test and the Bland-Altman plot. For stability tests, the initial results were compared with the day 1 (24±2 hours), day 3 (72±2 hours), and day 7 (168±2 hours) results, respectively. RESULTS: The difference in the test results obtained from the samples in each tube (V-Tube vs. BD-Tube, V-Tube vs. Greiner-Tube, and BD-Tube vs. Greiner-Tube) were satisfied with the Clinical Laboratory Improvement Amendments of 1988 allowable difference ranges. Except for four analytes (low-density lipoprotein cholesterol, magnesium, potassium, and thyroid-stimulating hormone), all analytes were within the allowable critical difference range based on biological variability. The paired t-test revealed significant differences between the results of nine assays for samples in V-Tube vs. BD-Tube and seven assays for samples in V-Tube vs. Greiner-Tube, but each set of results showed good correlations. The test results on different days showed a significant difference in several assays, but they were within the allowable difference range. CONCLUSIONS: The assay results for blood samples collected in SST V-Tubes were comparable to those obtained when blood was collected in BD Tubes and Greiner Tubes, and the blood collected in V-Tubes also showed excellent results in the stability tests.
Chemistry ; Chemistry, Clinical* ; Cholesterol ; Humans ; Lipoproteins ; Magnesium ; Potassium ; Thyroid Gland* ; Vacuum* ; Volunteers

To evaluate the potential risk of arteriosclerosis caused by desalinated seawater, Wistar rats were provided desalinated seawater over a 1-year period, and blood samples were collected at 0, 90, 180, and 360 days. Blood calcium, magnesium, and arteriosclerosis-related indicators were investigated. Female rats treated with desalinated seawater for 180 days showed lower magnesium levels than the control rats (P < 0.05). The calcium and magnesium levels in female rats and the magnesium level in male rats were lower than the levels in the controls, following treatment with desalinated seawater for 360 days (P < 0.05). Blood levels of arteriosclerosis-related lipid peroxidation indicators and C-reactive protein (CRP) in the treatment group did not differ from those in the controls. The levels of lipid peroxidation indicators and CRP in rats were not significantly affected by drinking desalinated seawater, and no increase in risk of arteriosclerosis was observed.
Animals ; Arteriosclerosis ; chemically induced ; Calcium ; blood ; Female ; Lipid Peroxidation ; Magnesium ; blood ; Male ; Rats ; Rats, Wistar ; Seawater ; chemistry ; Sodium Chloride ; chemistry

Surface characteristics and cellular response to titanium surfaces that had been implanted with calcium and magnesium ions using plasma immersion ion implantation and deposition (PIIID) were evaluated. Three different titanium surfaces were analyzed: a resorbable blast media (RBM) surface (blasted with hydroxyapatite grit), a calcium ionimplanted surface, and a magnesium ion-implanted surface. The surface characteristics were investigated by scanning electron microscopy (SEM), surface roughness testing, X-ray diffraction (XRD), and Auger electron spectroscopy (AES). Human bone marrow derived mesenchymal stem cells were cultured on the 3 different surfaces. Initial cell attachment was evaluated by SEM, and cell proliferation was determined using MTT assay. Real-time polymerase chain reaction (PCR) was used to quantify osteoblastic gene expression (i.e., genes encoding RUNX2, type I collagen, alkaline phosphatase, and osteocalcin). Surface analysis did not reveal any changes in surface topography after ion implantation. AES revealed that magnesium ions were present in deeper layers than calcium ions. The calcium ion- and magnesium ion-implanted surfaces showed greater initial cell attachment. Investigation of cell proliferation revealed no significant difference among the groups. After 6 days of cultivation, the expression of RUNX2 was higher in the magnesium ion-implanted surface and the expression of osteocalcin was lower in the calcium ion-implanted surface. In conclusion, ion implantation using the PIIID technique changed the surface chemistry without changing the topography. Calcium ion- and magnesium ion-implanted surfaces showed greater initial cellular attachment.
Alkaline Phosphatase ; Bone Marrow* ; Calcium* ; Cell Proliferation ; Chemistry ; Collagen Type I ; Durapatite ; Gene Expression ; Humans* ; Immersion ; Ions* ; Magnesium* ; Mesenchymal Stromal Cells* ; Microscopy, Electron, Scanning ; Osteoblasts ; Osteocalcin ; Osteogenesis ; Plasma ; Real-Time Polymerase Chain Reaction ; Spectrum Analysis ; Titanium* ; X-Ray Diffraction

This study aimed to conduct measurement uncertainty assessment of a new method for determination of Sudan colorants (Sudan I, II, III and IV) in food by high performance liquid chromatography (HPLC). Samples were extracted with organic solvents (hexane, 20% acetone) and first purified by magnesium trisilicate (2MgO·3SiO2). The Sudan colorants (Sudan I-IV) were also initially separated on C8 by gradient elution using acetonitrile and 0.1% (v/v) formic acid aqueous solution as the mobile phases and detected with diode-array detector (DAD). The uncertainty of mathematical model of Sudan I, II, III and IV is based on EURACHEM guidelines. The sources and components of uncertainty were calculated. The experiment gave a good linear relationship over the concentration from 0.4 to 4.0 μg/mL and spiked recoveries were from 74.0% to 97.5%. The limits of determination (LOD) were 48, 61, 36, 58 μg/kg for the four analytes, respectively. The total uncertainty of Sudan colorants (Sudan I, II, III and IV) was 810±30.8, 790±28.4, 750±27.0, 730±50.0 μg/kg, respectively. The recovery uncertainty was the most significant factor contributing to the total uncertainty. The developed method is simple, rapid, and highly sensitive. It can be used for the determination of trace Sudan dyes in food samples. The sources of uncertainty have been identified and uncertainty components have been simplified and considered.
Azo Compounds ; chemistry ; isolation & purification ; Chromatography, High Pressure Liquid ; methods ; Food Analysis ; methods ; Food Coloring Agents ; chemistry ; isolation & purification ; Humans ; Limit of Detection ; Magnesium Silicates ; chemistry ; Naphthols ; chemistry ; isolation & purification