Evaluation of contact angle and mechanical properties of resin monomers filled with graphene oxide nanofibers

Abstract This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior.

Resumo Este estudo in vitro sintetizou nanofibras híbridas embebidas em óxido de grafeno (GO), incorporando-as à uma resina composta experimental de monômeros para avaliar suas propriedades físico-mecânicas. Nanofibras híbridas inorgânica-orgânicas foram produzidas com soluções precursoras de fibras poli (d, l-lactídeo, PLA) preenchidas com GO a 1% em peso e microscopia eletrônica de varredura (MEV) e espectroscopia de raio-X de energia dispersiva (EDS) caracterizaram a morfologia e composição química das fibras. Monômeros de resina composta foram desenvolvidos e um total de 5% de nanofibras foi incorporado aos materiais experimentais. Três grupos foram desenvolvidos: G1 (monômeros de resina controle), G2 (monômeros de resina/ nanofibras de PLA) e G3 (monômeros de resina/nanofibras híbridas inorgânico-orgânicas). Ângulo de contato (n=3), resistência à flexão (n=22), módulo de elasticidade (n=22) e dureza Knoop (n=6) foram avaliados. A média das três endentações foi obtida para cada amostra. A normalidade dos dados foi avaliada pelo QQ Plot com envelopes simulados e analisada pelo método de Welch (p<0,05). No geral, as imagens de MEV mostraram forma regular de nanofibras, mas não alinhadas. A análise composicional de EDS (n=6) revelou a presença de carbono e oxigênio (presentes na composição do GO) e Si resultante do processo de funcionalização. Os resultados do ângulo de contato (°) e dureza (Kg/mm2) para cada grupo foram os seguintes, respectivamente: G1 (59,65±2,90; 37,48±1,86a), G2 (67,99±3,93; 50,56±1,03b) e G3 (62,52±7,40; 67,83±1,01c). G3 apresentou os maiores valores de dureza Knoop (67,83 kg/mm2), e a resistência à flexão de todos os grupos foi prejudicada. A resina composta experimental composta por nanofibras híbridas com GO apresentou maiores valores de dureza e comportamento hidrofílico.

Identification of Traditional Chinese Medicine Seahorses Using Graphene Oxide-based Fluorescent Sensing Technology / 中国实验方剂学杂志

ObjectiveTo establish a method for seahorse identification based on graphene oxide fluorescence sensing technology， and to provide a new research idea for identification of traditional Chinese medicine. MethodThe fluorophore FAM was labeled at the 5' end of the specificity upstream primer Ja-F of Hippocampus japonicus as the nucleic acid probe FAM-ssDNA （single strand DNA）. The recognition site of RNA polymerase Ⅱ was added to its specific downstream primer Ja-R as Ja-R1. The seahorse samples were amplified with Ja-F/Ja-R1 primers， and the ssDNA of H. japonicus was obtained by reverse transcription of the amplification products using vitro transcription method. The 20 μL nucleic acid probe FAM-ssDNA （500 nmol·L-1） was incubated at 90 ℃ for 5 min， and was gradually cooled to room temperature. Different volume of graphene oxide solution （100 mg·L-1） and Tris hydroxymethyl amino methane HCl （Tris-HCl） buffer （50 mmol·L-1） were added into each probe solution to make a final reaction volume of 1 mL. The fluorescence intensity of each sample was measured after mixing and placing different times at room temperature away from the light. So that the most appropriate graphene oxide concentration and reaction time were screened for constructing the best nucleic acid probe-graphene oxide biosensor. Adding probe complementary sequence FAM-ssDNA-match solution into the nucleic acid probe-graphene oxide solution， the fluorescence intensity of the reaction mixture was measured after being placed different times at room temperature. Therefore， the optimal reaction time of fluorescence recovery was screened and the feasibility of the sensor was tested. The sensitivity was detected via adding ddH2O as the blank control and different concentration H. japonicus ssDNA into each nucleic acid probe-graphene oxide solution， respectively. Finally， the commercial hippocampal were identified using the optimal experimental condition， and the feasibility of this method for the identification of Chinese medicinal materials was verified. ResultThe fluorescence of 1 mL reaction mixture including 10 nmol·L-1 nucleic acid probe FAM-ssDNA and 12 mg·L-1 go solution for 20 min at room temperature away from the light could be completely quenched. Feasibility test of the biosensor showed that when probe complementary sequence FAM-ssDNA-match solution （final concentration 90 nmol·L-1） was added to the biosensor solution and reacted 1 h reaction at room temperature， the fluorescence signal was significantly enhanced. Sensitivity test showed that the minimum concentration of ssDNA detected by this method was about 10 mg·L-1. This method was used to detect commercial seahorses， and only H. japonicus samples had obvious fluorescence signal. ConclusionThe graphene oxide-based fluorescent sensing technology could be used for zoological origin survey of commercial hippocampus.

Effect of graphene-oxide-modified osteon-like concentric microgrooved surface on the osteoclastic differentiation of macrophages / 华西口腔医学杂志

OBJECTIVES@#This study aimed to investigate the effect of new biomimetic micro/nano surfaces on the osteoclastic differentiation of RAW264.7 macrophages by simulating natural osteons for the design of concentric circular structures and modifying graphene oxide (GO).@*METHODS@#The groups were divided into smooth titanium surface group (SS), concentric microgrooved titanium surface group (CMS), and microgroove modified with GO group (GO-CMS). The physicochemical properties of the material surfaces were studied using scanning electron microscopy (SEM), contact-angle measurement, atomic force microscopy, X-ray photoelectron spectroscopy analysis, and Raman spectroscopy. The effect of the modified material surface on the cell biological behavior of RAW264.7 was investigated by cell-activity assay, SEM, and laser confocal microscopy. The effect on the osteoclastic differentiation of macrophages was investiga-ted by tartrate-resistant acid phosphatase (TRAP) immunofluorescence staining and quantitative real-time polymerase chain reaction (qRT-PCR) experiments.@*RESULTS@#Macrophages were arranged in concentric circles along the microgrooves, and after modification with GO, the oxygen-containing groups on the surface of the material increased and hydrophilicity increased. Osteoclasts in the GO-CMS group were small in size and number and had the lowest TRAP expression. Although it promoted the proliferation of macrophages in the GO-CMS group, the expression of osteoclastic differentiation-related genes was lower than that in the SS group, and the difference was statistically significant (P<0.05).@*CONCLUSIONS@#Concentric circular microgrooves restricted the fusion of osteoclasts and the formation of sealing zones. Osteomimetic concentric microgrooves modified with GO inhibited the osteoclastic differentiation of RAW 264.7 macrophages.

Analysis of anticancer compound,indole-3-carbinol,in broccoli using a new ultrasound-assisted dispersive-filter extraction method based on poly(deep eutectic solvent)-graphene oxide nanocomposite / 药物分析学报

Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature.In this study,a rapid,accurate,and low-cost ultrasound-assisted dispersive-filter extraction(UADFE)technique based on poly(deep eutectic solvent)-graphene oxide(PDES-GO)adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time.PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption.UADFE was developed by combining dispersive solid-phase extraction(DSPE)and filter solid-phase extraction(FSPE)to realize rapid extraction and separation.Based on the above two strategies,the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography(HPLC)allowed the rapid(15-16 min),accurate(84.3％-96.4％),and low-cost(adsorbent:3.00 mg)analysis of I3C in broccoli and was superior to solid-phase extraction,DSPE,and FSPE methods.The proposed method showed remarkable linearity(r=0.9998;range:0.0840-48.0 μg/g),low limit of quantification(0.0840 μg/g),and high precision(relative standard deviation≤5.6％).Therefore,the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.

Accurate construction of cell membrane biomimetic graphene nanodecoys via purposeful surface engineering to improve screening efficiency of active components of traditional Chinese medicine

Biomimetic nanoengineering presents great potential in biomedical research by integrating cell membrane (CM) with functional nanoparticles. However, preparation of CM biomimetic nanomaterials for custom applications that can avoid the aggregation of nanocarriers while maintaining the biological activity of CM remains a challenge. Herein, a high-performance CM biomimetic graphene nanodecoy was fabricated via purposeful surface engineering, where polyethylene glycol (PEG) was used to modifying magnetic graphene oxide (MGO) to improve its stability in physiological solution, so as to improve the screening efficiency to active components of traditional Chinese medicine (TCM). With this strategy, the constructed PEGylated MGO (PMGO) could keep stable at least 10 days, thus improving the CM coating efficiency. Meanwhile, by taking advantage of the inherent ability of HeLa cell membrane (HM) to interact with specific ligands, HM-camouflaged PMGO showed satisfied adsorption capacity (116.2 mg/g) and selectivity. Finally, three potential active components, byakangelicol, imperatorin, and isoimperatorin, were screened from Angelica dahurica, whose potential antiproliferative activity were further validated by pharmacological studies. These results demonstrated that the purposeful surface engineering is a promising strategy for the design of efficient CM biomimetic nanomaterials, which will promote the development of active components screening in TCM.

Biological and physico-mechanical properties of poly (methyl methacrylate) enriched with graphene oxide as a potential biomaterial / Propiedades físicas-mecánicas-biológicas del poli (metilmetacrilato) enriquecido con óxido de grafeno como potencial biomaterial

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulp-dental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: The GO was characterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's posthoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 µm. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical mechanical properties of PMMA.

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulpdental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: T he G O w as c haracterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical-mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's post-hoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 ?m. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical-mechanical properties of PMMA.

A sensitive electrochemical detection of metronidazole in synthetic serum and urine samples using low-cost screen-printed electrodes modified with reduced graphene oxide and C60 / 药物分析学报

Monitoring the concentration of antibiotics in body fluids is essential to optimizing the therapy and minimizing the risk of bacteria resistance,which can be made with electrochemical sensors tailored with appropriate materials.In this paper,we report on sensors made with screen-printed electrodes(SPE)coated with fullerene(C60),reduced graphene oxide(rGO)and Nafion(NF)(C60-rGO-NF/SPE)to determine the antibiotic metronidazole(MTZ).Under optimized conditions,the C60-rGO-NF/SPE sensor exhibited a linear response in square wave voltammetry for MTZ concentrations from 2.5×10-7 to 34×10-6 mol/L,with a detection limit of 2.1×10-7 mol/L.This sensor was also capable of detecting MTZ in serum and urine,with recovery between 94％and 100％,which are similar to those of the standard chromatographic method(HPLC-UV).Because the C60-rGO-NF/SPE sensor is amenable to mass pro-duction and allows for MTZ determination with simple principles of detection,it fulfills the requirements of therapeutic drug monitoring programs.

Synthesis and electrochemical properties of environmental free L-glutathione grafted graphene oxide/ZnO nanocomposite for highly selective piroxicam sensing / 药物分析学报

A simple and reliable strategy was proposed to engineer the glutathione grafted graphene oxide/ZnO nanocomposite(glutathione-GO/ZnO)as electrode material for the high-performance piroxicam sensor.The prepared glutathione-GO/ZnO nanocomposite was well characterized by X-ray diffraction(XRD),Fourier transform infrared spectrum(FTIR),X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FE-SEM),cyclic voltammetry(CV),electrochemical impedance spectros-copy(EIS)and differential pulse voltammetry(DPV).The novel nanocomposite modified electrode showed the highest electrocatalytic activity towards piroxicam(oxidation potential is 0.52 V).Under controlled experimental parameters,the proposed sensor exhibited good linear responses to piroxicam concentrations ranging from 0.1 to 500 μM.The detection limit and sensitivity were calculated as 1.8 nM and 0.2 μA/μM·cm2,respectively.Moreover,it offered excellent selectivity,reproducibility,and long-term stability and can effectively ignore the interfering candidates commonly existing in the pharmaceutical tablets and human fluids even at a higher concentration.Finally,the reported sensor was successfully employed to the direct determination of piroxicam in practical samples.

Removal of Shield Needles from Graphene Oxide Thrombus and Preparation / 中国医疗器械杂志

Atherosclerosis is a chronic inflammatory disease commonly seen in clinical practice. It can lead to thickening of vascular intima, occlusion of lumen stenosis and thrombosis, leading to angina pectoris, hypertension, myocardial infarction and other diseases, posing a serious threat to human life and health. This study provides a method for removing shield needles from graphene oxide thrombus and its preparation. The graphene oxide shield needle mainly includes flexible rotating shaft, radial flexible rod, rotating needle, adsorption main pipe and dosing main pipe, laser measuring device, high definition camera and other structures, which has the following advantages:firstly, it achieves multi-angle rotation grinding thrombosis, precise rotation grinding, avoids vascular damage and infection; secondly, thrombolytic drugs can be applied in the process of rotary grinding and small thrombus can be adsorbed to effectively avoid secondary embolization of blood vessels; thirdly, it a coating of graphene oxide on a rotating needle, which protects against bacteria and infection. This study has practical reference value for the development of thrombotherapy and the application of graphene in the medical field.

Effects of Oridonin-loaded Chitosan Graphene Oxide on the Proliferation and Apoptosis of A 549 Cells / 中国药房

OBJECTIVE：To study the effects of chitosan graphene oxide car rier（CS-GO）loaded with oridonin （CS-GO- oridonin）on the proliferation and apoptosis of human lung cancer A 549 cells. METHODS ：Taking A 549 cells as objects ，the survival rate of cells were detected by CCK- 8 method after treated with different concentrations of CS-GO （3，6，12，24，48 μg/mL）and CS-GO-oridonin loaded with same mass of oridonin （3，6，12，24，48 μg/mL，by the weight of oridonin ，the same below）. IC 50 of CS-GO-oridonin was calculated. The cell morphology were observed by microscope after treated with CS-GO and CS-GO-oridonin（both 32 μg/mL）for 2，4，10，24 h. The uptake of CS-GO ，oridonin，CS-GO-orionin（all 32 μg/mL）by cells was observed with fluorescence labeling method. The apoptosis of cells and the content of ROS were observed by flow cytometry after treated with different concentrations of CS-GO （16，32，64 μg/mL）and CS-GO-oridonin （16，32，64 μg/mL）. The expression of anti-apoptosis related proteins （Mcl-1，Bax and Bak ）were detected by Western blot. RESULTS ：After treated with different concentrations of CS-GO ，the survival rate of cells was still above 90％ ；after treated with different concentrations of CS-GO-oridonin，the survival rate of cells showed a downward trend ，and was significantly lower than that of CS-GO group （P＜ 0.01）；IC50 of CS-GO-oridonin was 32.61 μg/mL. After CS-GO treatment，the cell morphology did not change significantly ；after CS-GO-oridonin treatment ，the cells shrunk and fell off in clusters ，and the suspended matter increased ；the fluorescence of oridonin and CS-GO-orionin taken up by cells was enhanced than CS-GO. Compared with blank group ，there was no significant change in the apoptosis rate ，the content of ROS and the expression of apoptosis-related protein in 16，32，64 μg/mL CS-GO groups（P＞0.05）；apoptosis rate ，the content of ROS ，the protein expression of Bax and Bak in 16，32，64 μg/mL CS- GO-oridonin groups were increased significantly ，while the protein expression of Mcl- 1 were decreased significantly. Above indexes were significantly high er or lower than the same concentration CS-GO group （P＜0.05）. CONCL USIONS：CS-GO dose not affect the proliferation and apoptosis of A 549 cells；CS-GO-oridonin has obvious inhibition and apoptosis promoting effect on cells ，which may be related to increasing ROS production and regulating the expression of apoptosis related proteins.

Effects of graphene on the proliferation, migration and morphology of dental pulp stem cells / 口腔疾病防治

Objective@# To investigate the effects of graphene on the proliferation, migration and cell morphology of dental pulp stem cells (DPSCs).@*Methods@#Graphene powder was prepared by the oxidation-reduction method, and a 0.5 mg/mL graphene dispersion was prepared. Raman spectroscopy and atomic force microscopy were used to characterize the structure and surface morphology of graphene. DPSCs were isolated and cultured in vitro. MTT assay was used to detect the effects of different concentrations of graphene dispersions (0, 1, 5, 10, 20, 50, 100 μg/mL) on the proliferation and wound healing assay was used to detected the migration abilities of DPSCs. The effects of graphene on the morphology of DPSCs were observed by immunofluorescence staining. @*Results @# In the present study, compared with the control group (0 μg/mL), the proliferation of DPSCs in the 100 μg/mL group was inhibited at 72 h (P < 0.05), and the proliferation of DPSCs in the other groups was not significantly affected (P > 0.05). Graphene dispersions at 10 and 20 μg/mL promoted the migration of DPSCs (P < 0.05). After being cultured in 20 μg/mL graphene dispersions for 3 days, the DPSCs showed a large and orderly cytoskeletal structure, and the spread area of cells was not significantly different from that of the control group (0 μg/mL) (P > 0.05), while some cells had the morphological characteristics of nerve cells.@* Conclusion @# Graphene has good biocompatibility and is expected to be a suitable material for tissue engineering within fitting concentration.

Study on the adsorption of inflammatory cytokines and blood compatibility of graphene oxide electrostatic self-assembled polyester material / 中国输血杂志

【Objective】 To investigate the removal efficacy of inflammatory cytokines and blood compatibility of modified PBTNF. 【Methods】 Acrylic acid (AA) was firstly UV-grafted onto the surface of PBTNF to negatively charge the surface of the material. Subsequently, the three positively charged polyelectrolytes, DA, PEI, and CS were respectively electrostatic self-assembled with GO on the surface of PBTNF, forming two layers of film with GO as the outer layer: PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2, PBTNF-(CS/GO)2. 【Results】 Scanning electron microscopy results showed that compared with the PBTNF grafted with AA, the adhesion of particles was observed on the surface of the three modified materials, and the photo shows that the color of the material surface was deepened after electrostatic self-assembly. The results of wettability showed that the surface hydrophilicity was significantly improved, indicating that the electrostatic self-assembled membrane was successfully immobilized on the surface of PBTNF. The removal efficiency (%) of IL-1β for PBTNF-(DA/GO)2, PBTNF-(PEI/GO)2 and PBTNF-(CS/GO)2 were 69.00±7.36 vs -2.35±2.69 vs -1.59±3.26 (P<0.05). The removal efficiency of IL-6 (%) were 40.15±1.86 vs -13.46±5.72 vs -1.21±3.41 (P<0.05). The removal efficiency of IL-8 (%) were 96.90±0.97 vs 17.84±11.74 vs 43.68±17.38 (P<0.05). The removal efficiency of TNF-α (%) was 44.46±2.50 vs 14.90±7.12 vs 20.64±1.22 (P<0.05). Plasma protein adsorption results (total protein, immunoglobulin G, albumin) and red blood cell deformability index showed that there was no statistical difference among the three modified PBTNFs and the control group (P>0.05). Although the red blood cell osmotic fragility (g/L) of the three modified PBTNFs is higher than that of the former: control group vs PBTNF-(DA/GO)2 vs PBTNF-(PEI/GO)2 vs PBTNF-(CS/GO)2: 4.39±0.05 vs 4.62±0.02 vs 4.48±0.03 vs 4.90±0.03 (P<0.05), the hemolysis rate (%) of them were all less than 5%, and PBTNF-(DA/GO)2 performed the lowest hemolysis rate which was (0.03±0.01)% (compared with PBTNF-(PEI/GO)2, P<0.05). The coagulation function test results showed that compared with the control group, the fibrinogen (g/L) of the three modified PBTNFs had no statistical difference (P>0.05); the activated partial thrombo plastin time (S) slightly extended, but all within the normal range of clinical standard; and the prothrombin time (S) of PBTNF-(CS/GO)2 was prolonged(P<0.05). 【Conclusion】 Among the three positively charged polyelectrolytes, including DA, PEI, and CS, PBTNF-(DA/GO)2 performed the best removal rate of inflammatory cytokines, and the blood compatibility evaluation results showed that PBTNF-(DA/GO)2 had no significant effect on red blood cells and coagulation function. Consequently, in the study of inflammatory cytokines adsorption, DA is expected to be the optimal polyelectrolyte assembling with GO for further research.

Effect of graphene oxide/polycaprolactone composite electrospun nanofibrous materials on the differentiation of rat brown adipose stem cells into cardiomyocytes / 国际药学研究杂志

Objective: To prepare graphene oxide(GO)/polycaprolactone(PCL)composite matrix nanomaterials with different concentrations, and investigate effects of the nanomaterials on the myocardial differentiation of rat brown adipose stem cells (BASC)in vitro. Methods: The GO/PCL composite nanofiber materials were prepared by electrospinning technology. The biocompatibility of the nanomaterials was tested by the CCK-8 assay after cultivation of the BASC on the pure PCL and GO/PCL composite nanofibers, and the characterization of the nanofiber materials was performed by the scanning electron microscopy(SEM)and electrical conductivity measurement. The expression of cardiomyocyte-related proteins was examined by the cytological method and immunofluorescence staining. The GO/PCL composite nanofiber materials were systematically evaluated for their effect on the viability, proliferation and myocardial differentiation of BASC. Results: The GO/PCL composite nanofiber materials showed no obvious cytotoxicity at the 0.1 mg/ml GO concentration. The statistical results for the protein fluorescence intensities showed that the expression of the cardiomyocyte specific protein, α-actinin, and the intercalated disc-related protein, connexin-43(CX-43), was significantly increased in the GO/PCL group than in the PCL group(P<0.05). The cytoskeletal staining results showed that, compared with the PCL group, the cells in the GO/PCL group showed a long spindle-like stretch similar to the natural myocardial cell bundle, and the growth direction had a certain polarity. Conclusion: This study successfully prepared GO/PCL composite nanomaterials, which could promote the differentiation of BASCs into cardiomyocytes and the expression of intercalated disc-related proteins.

Preparation and Characterization of Glycyrrhetinic Acid-modified Docetaxel Magnetic Nanoparticles / 中国药房

OBJECTIVE：To pre pare Glycyrrhetinic acid-modified docetaxel magnetic nanoparticles （GA-DTX-NGO/IONP- NPs），and to evaluate its physicochemical properties. METHODS ：Magnetic nano graphene oxide （NGO/IONP）was chosen as the anti-tumor drug carrier ，docetaxel（DTX）as the model drug and glycyrrhetinic acid （GA）as the target molecule. Firstly ，NGO/ IONP was synthesized by hydrothermal method and GA-CS was synthesized by amidation reaction. Fourier IR spectrometer ，DSC and vibration sample magnetic measuring instrument were used to characterize NGO/IONP and GA-CS. GA-DTX-NGO/IONP-NPs Huperzine A in the nicotinic acetylcholine receptor alleviates Aβ -induced 1-42 treatment of Alzheimer ’s disease and vascular dementia ：a neurotoxicity via downregulation of p 38 and JNK MAPK meta-analysis[J]. Evid Based Complement Alternat Med ， signaling pathways[J]. Neurochem Int ，2018. DOI ：10. 2014. DOI ：10.1155/2014/363985. 1016/j.neuint.2018.09.005. were prepared by the ion gelation method. TEM and particle size analyzer were used to observe and determine the morphology ， particle size and Zeta potential of GA-DTX-NGO/IONP-NPs ；the ultrafiltration-centrifugation method was used to determine encapsulation efficiency and drug loading amount ；the magnetic properties were investigated by investigating the state with or without external magnetic field ；the photothermal conversion test was carried out with laser irradiation of 808 nm. RESULTS ：NGO/ IONP and GA-CS were successfully synthesized ，and NGO/IONP exhibited superparamagnetism characteristics. GA-DTX-NGO/ IONP-NPs were spherical under TEM ，the particle size was （262.8±4.23）nm and the Zeta potential was （13.6±1.51）mV. The encapsulation rate and drug loading amount were （94.29±0.50）％ and（17.12±0.12）％，respectively. GA-DTX-NGO/IONP-NPs were black in appearance and evenly dispersed. Under the external magnetic field ，the magnetic nanoparticles could move directionally，showing good magnetic properties. GA-DTX-NGO/IONP-NPs showed a good concentration- and time-dependent photothermal conversion effect under 808 nm laser irradiation. CONCLUSIONS ：GA-DTX-NGO/IONP-NPs are successfully prepared. This study could provide some theoretical basis for the combined treatment of magnetic heating-chemotherapy for liver tumors.

Fluorescent labeling application of graphene oxide quantum dots in living human periodontal ligament stem cells / 医学研究生学报

ObjectiveNano-graphene oxide quantum dots (GOQDs) can be used to target fluorescent markers. The stem cell labeling is an important method in studying stem cell treatments. Our study aims to explore the possibility of using GOQDs as living cell fluorescent marker materials for human periodontal ligament stem cells (hPDLSCs), and to evaluate the biosecurity and effect as live cell fluorescence markers of GOQDs.Methods GOQDs were testified by TEM, DLS, UV-vis, and PL spectra. hPDLSCs were obtained by tissue cultivation and separated by single cell-derived colony selection. Then the source of the cells was carried out by immunocytochemical staining of anti-vimentin, anti-cytokeratin, and multipotent differentiation was used in the identification of stem cells. hPDLSCs were incubated with different concentrations of GOODs (0, 10, 25, and 50 μg/mL) for 24h and 72 h. Cytotoxicity and proliferation effects were determined using CCK-8, and cell cycles were detected using flow cytometry after the co-culture of GOQDs and hPDLSCs. The fluorescent labeling effect of GOQDs was tested using laser scanning confocal microscopy.ResultsThe characterization of GOQDs showed that the nanoparticles were evenly dispersed in water and showing blue light at 365 nm. TEM and DLS showed GOQDs had good dispersion, and the particle size was (6.36±1.41) nm. Immunocytochemical staining of anti-vimentin was positive while anti-cytokeratin was negative. The results of cytotoxicity showed there were no significant differences in cell activity after incubated with different concentrations of GOODs (0, 5, 10, 25, 50, 100, 200, and 400 μg/mL) (P>0.05), and there was no significant decrease in cell activity between 24h and 72h (P>0.05). There was no significant difference in the proportional distribution of G1, G2, and S phases between the two concentrations of GOQDs (0 μg/mL and 50 μg/mL) (P>0.05). Fluorescent images showed that GOQDs could enter the cell membrane and increase the fluorescence intensity at the concertation of 50 μg/mL.ConclusionGOQDs were confirmed to have good biocompatibility and could be used for live cell labeling of hPDLSCs.

Fluorescent labeling application of graphene oxide quantum dots in living human periodontal ligament stem cells / 医学研究生学报

ObjectiveNano-graphene oxide quantum dots (GOQDs) can be used to target fluorescent markers. The stem cell labeling is an important method in studying stem cell treatments. Our study aims to explore the possibility of using GOQDs as living cell fluorescent marker materials for human periodontal ligament stem cells (hPDLSCs), and to evaluate the biosecurity and effect as live cell fluorescence markers of GOQDs.Methods GOQDs were testified by TEM, DLS, UV-vis, and PL spectra. hPDLSCs were obtained by tissue cultivation and separated by single cell-derived colony selection. Then the source of the cells was carried out by immunocytochemical staining of anti-vimentin, anti-cytokeratin, and multipotent differentiation was used in the identification of stem cells. hPDLSCs were incubated with different concentrations of GOODs (0, 10, 25, and 50 μg/mL) for 24h and 72 h. Cytotoxicity and proliferation effects were determined using CCK-8, and cell cycles were detected using flow cytometry after the co-culture of GOQDs and hPDLSCs. The fluorescent labeling effect of GOQDs was tested using laser scanning confocal microscopy.ResultsThe characterization of GOQDs showed that the nanoparticles were evenly dispersed in water and showing blue light at 365 nm. TEM and DLS showed GOQDs had good dispersion, and the particle size was (6.36±1.41) nm. Immunocytochemical staining of anti-vimentin was positive while anti-cytokeratin was negative. The results of cytotoxicity showed there were no significant differences in cell activity after incubated with different concentrations of GOODs (0, 5, 10, 25, 50, 100, 200, and 400 μg/mL) (P>0.05), and there was no significant decrease in cell activity between 24h and 72h (P>0.05). There was no significant difference in the proportional distribution of G1, G2, and S phases between the two concentrations of GOQDs (0 μg/mL and 50 μg/mL) (P>0.05). Fluorescent images showed that GOQDs could enter the cell membrane and increase the fluorescence intensity at the concertation of 50 μg/mL.ConclusionGOQDs were confirmed to have good biocompatibility and could be used for live cell labeling of hPDLSCs.

Surface-enhanced raman scattering technology-based graphene oxide/gold nanorods in detection of circulating tumor cells / 第二军医大学学报

Objective To develop a method combining surface-enhanced Raman scattering (SERS) spectrum and electrostatic adsorption for detecting circulating tumor cells. Methods Graphene oxide was non-covalently functionalized by poly(sodium-p-styrenesulfonate) (PSS), and graphene oxide/gold nanorod (GO/GNR) hybrids were in situ synthesized via gold seeding growth approach. Then, GO/GNR hybrids were non-covalently functionalized by poly dimethyl diallyl ammonium chloride (PDDAC) to make the surface of GO/GNR positively charged. GO/GNR hybrids would target the tumor cells by electrostatic interaction. SERS technology was used to detect the composites of GO/GNR-tumor cells. The blood samples of healthy volunteers were collected, and the tumor cells of different densities were added to the blood samples to make simulated blood samples. The tumor cells in simulated blood samples were detected using the above methods. Results Positively charged GO/GNR hybrids could efficiently target the tumor cells. SERS spectroscopy could detect tumor cells within 50 to 10 000 cells. However, white blood cells might interfere the detection of tumor cells. Conclusion GO/GNR hybrids may serve as SERS probes for detection of circulating tumor cells via Raman spectroscopy.

Research progress in graphene derivatives promoting bone regeneration / 中华口腔医学杂志

Graphene derivatives are the new bioactive material with good physical and chemical properties and excellent biocompatibility. It has been found that graphene derivatives can improve the mechanical properties of biomaterials and promote the adhesion, proliferation and differentiation of osteoblast-related cells, so as to promote implant-bone bonding and repair of bone defects. This makes it a research hotpot in the field of bone tissue regeneration. In this paper, the mechanism of graphene derivatives promoting bone regeneration and their application in the oral field were reviewed, so as to provide theoretical basis for their application in basic and clinical research.

Mechanical properties and cell compatibility of a chitosan-graphene oxide guided bone regeneration composite membrane / 中华口腔医学杂志

Objective@#To explore the feasibility of graphene oxide (GO)-chitosan (CS) guided bone regeneration composite membrane being used as a new guided bone regeneration (GBR) membrane by testing its tensile strength and its effect on the proliferation of human gingival fibroblasts (HGF).@*Methods@#The CS solution and GO solution were mixed in following ratios, ultrasonically crushed and dispersed, and formed into membranes by self-evaporation. Composite membrane with 0.5%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% GO in CS was prepared. The tensile strength of the composite membranes was tested by mechanical universal testing machine (n=6). The microstructure of the composite membrane with the best tensile strength was observed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction was used to characterize the ingredients of the material. A group of samples was prepared again with the proportion of the highest tensile strength composite membrane, and were immersed in a sodium hydroxide solution for acid removal. The tensile strength of the new group of samples was tested. The newly extracted impacted teeth were collected from the Department of Oral and Maxillofacial Surgery, Stomatologic Hospital and College, Anhui Medical University, and the gingival tissues remained on the teeth were taken for primary HGF and were cultured to P2 generation, which were identified by immunocytochemical staining methods. Cell counting kit-8 (CCK-8) was applied to detect cell counts in the blank control group, the pure CS membrane group, and the composite membrane group with the highest tensile strength (n=5) and all groups co-cultured with the HGF for 24 h and 48 h.@*Results@#After adding GO, the cross-section of the composite membrane was in an ordered layer structure. X-ray diffraction analysis showed that GO could be found in the composite membrane. The tensile strength increased with the increase of GO ratio. When the mass fraction of GO in CS was 4.0%, the tensile strength reached (134.8±7.3) MPa and the tensile strength reached (144.6±8.1) MPa after deacidification of the composite membrane. The CCK-8 test of HGF showed that there was no significant difference in absorbance between the pure CS membrane group and the GO/CS composite membrane group when they were compared with the blank control group (P>0.05).@*Conclusions@#When the mass fraction of GO in CS is 4.0%, the composite membrane has the best tensile strength. The composite membrane showes good cytocompatibility, which lays a foundation for further in vivo experiments and the development of a new generation of GBR membrane.

Preparation and cytocompatibility of porous zirconia scaffold modified by graphene oxide for bone tissue engineering / 医学研究生学报

Objective In order to meet the needs of maxillofacical bone defect repair, the aim of this study was to synthesize graphene oxide(GO) modified three-dimensional conneted nano- zirconia(ZrO2) bone tissue engineering scaffold and evaluate its surface morphology, compressive strength and cytocompatibility. Methods GO was synthesized by a modified Hummers method and then was testified by scanning electron microscope, transmission electron microscopy and fourier transform infrared spectroscopy. ZrO2 scaffold was modified by different concentrations(0.5,1.0,1.5mg/mL) of GO dispersion via a silane-mediated method. The composite scaffold with uniform GO coating was chosen for compressive strength test and co-cultured with human dental pulp stem cells(hDPSCs). Actin staining was used to observe the growth of the cells on the scaffold, and MTS was used to detect the cell activity. Results The characterization results showed that, under scanning electron microscope, the GO was flaky and the surface morphology of folds could be seen. Part of the GO layer folds up at the edge. Under transmission electron microscopy, the GO was clearly observed to have a gossylike, translucent and slightly wrinkled lamellar structure. The crystal structure in this area in the high-resolution filter image showed a six-member ring structure like graphite. Under high power electron microscope, the 1.0mg/ml GO-ZrO2 scaffold could be seen to deposit a thin layer of GO at the crack of the scaffold skeleton, connecting the two ends of the crack, and lamellar GO with folds could be observed on the surface of ceramic particles. The comparison of mechanical properties showed that the compression strength of GO-ZrO2 scaffold was sgnificantly increased compared with that of ZrO2 scaffold[（1.292±0.087）vs（1.031±0.076）, P<0.05]. Compared with the simple ZrO2 scaffold, the GO-ZrO2 scaffold showed more dense extension and adhesion to the surface of scaffolds, showing more active cell proliferation. The cell viability test showed that the viability of hDPSCs was significantly improved on GO-ZrO2 scaffold after 1, 3 and 5 days of proliferation compared with the simple ZrO2 scaffold(P<0.05). Conclusion The ZrO2 scaffold modified by GO improved compressive strength, promoted the early proliferation of hDPSCs with good cytocompatibility.