Home Physical Sciences A study on the bacterial adhesion of Streptococcus mutans in various dental ceramics: In vitro study
Article Open Access

A study on the bacterial adhesion of Streptococcus mutans in various dental ceramics: In vitro study

  • Fuat Bislimi EMAIL logo , Jagoda Bajevska , Mrinmoy Garai and Arianit A. Reka
Published/Copyright: November 4, 2020

Abstract

Streptococcus mutans (S. mutans) has been identified as a major etiologic agent of human dental caries and forms a significant proportion of oral streptococci in carious lesions. This study investigates the correlation of surface properties (effect of contact angle [CA] and free surface energy) on three restorative materials (zirconia, nickel–chromium–molybdenum alloy and composites) used in dental prosthetics with bacterial adhesion to S. mutans. Ten samples of each material (zirconia, nickel–chromium–molybdenum alloy and composites) of 8 mm diameter and 2.5 mm thickness were used. Aqueous CA measurements, free surface energy and bacterial adhesion to the sample surfaces were performed. Bacterial adhesion is determined by planting samples in the blood agar cultures and using an electron microscope (scanning electron microscopy [SEM]). The highest values of bacterial adhesion are found in composites, followed by the metal alloy, while the lowest values are observed in zirconia. Measurements show that zirconia has 17 bacteria; Ni–Cr–Mo alloy has 65, while the composite has 80 bacteria. The composites showed the highest degree of bacterial adhesion, compared to the other investigated materials, which correlates with the free surface energy of the samples (24.31 mJ/m2 for zirconia, 31.78 mJ/m2 for Ni–Cr–Mo alloy and 48.82 mJ/m2 for the composite).

1 Introduction

Dental implants and prosthodontic restorations are one of the most routinely used treatment options for the replacement of missing teeth [1,2,3]. The oral microflora and its interactions with the implant substrata seem to have a crucially impact on the long-term success or failure of dental implants. Once the implant surfaces are exposed to the human oral cavity, they are promptly colonized by microorganisms [4,5,6,7].

The biological response to the dental implants or prosthodontic restorations is determined by a number of physical and chemical features. These features include mechanical properties and physiochemical properties such as chemical composition, surface energy, surface wettability and surface topography [8].

Surface topography plays a very important role in bacterial adhesion, such as hydrophobicity, free surface energy, chemical composition and smoothness or roughness of surfaces. Microscopic studies of early dental plaque formations have shown adhesion of the initial colonized bacteria along the cracks and pits in the enamel, indicating the influence of surface structure on bacterial adhesion [9].

The success of esthetic restorations on a long-term basis depends on the quality and quantity of the attached biofilm. Initial attachment and subsequent colonization of bacteria on the surface of restorative materials is key to the pathogenesis of secondary caries promoted in particular by S. mutans and Streptococcus sobrinus (S. sobrinus). S. mutans has been identified as the major etiologic agent of human dental caries and forms a significant proportion of oral streptococci in carious lesions [10,11].

The various types of materials and their specific textures and physicochemical surface properties influence the quantity and quality of microbial colonization [12,13,14,15]. Therefore, knowledge of bacterial adhesion and subsequent biofilm formation (multicellular structures with microbial cells embedded in the extracellular matrix) is important for the study of bacterial pathogenicity. The human mouth provides a unique environment for the formation of complex biofilms; for example, it hosts more than 1,000 species of microorganisms [16]. Among several microorganisms, bacteria are a major group and are capable of forming biofilms. Thus, it is important to know the mechanisms involved in bacterial adhesion in various materials used.

Today, in dental prosthetics, different materials are used, which have different physicochemical properties and act differently on the bacterial adhesion of S. mutans. In nickel–chromium alloys, despite the good physical chemical properties of the material, biofilm formation on its surface is crucial. The same problem is present in composite resins used in dentistry; as in some complex resins, bacterial adhesion is stimulated by the released residual monomer [17].

This study investigates the correlation of surface characteristics (effect of contact angle [CA] and free surface energy) on three restorative materials (zirconia, nickel–chromium–molybdenum alloy and composites) used in dental prosthetics with bacterial adhesion (by means of the test specie S. mutans).

2 Materials and methods

For the purpose of studying the bacterial adhesion of S. mutans in various dental ceramics, three various starting materials were used: zirconium (Ceramill, Zolid FX White, Germany), metal alloy (Kera N, Eisenbacher Dentalwaren ED-GMBH, Germany) and composite (Sr ADORO – Ivoclar Vivadent, Liechtenstein). Ten specimens in cylindrical shape (dimensions: 8 mm in diameter and 2.5 mm in thickness) from all three types of starting are used during this research. The surfaces of the specimens were treated with standard polishing methods as specified by the material manufacturer.

To form biofilm formations for further analysis, we used S. mutans bacteria, reference strain ATCC 35668, which according to the manufacturer’s instructions was developed in laboratory conditions in Petri dishes with 5% blood agar incubation of the plates at 37°C in an incubator with microaerophilic conditions at 10% CO2 for 24 h. Bacteria obtained in culture are used to make a bacterial suspension at a concentration of 0.5 Mc Farland. The concentration of bacteria in the suspension is measured with the DensiCHEK Plus-bio Merieux apparatus. The samples will then be cleaned and sterilized in an autoclave for 30 min at 121°C. Each set of samples (3 sets of 10 samples) will be covered with the bacterial suspension for 15 min at 37°C; the samples were removed from the suspension and washed with physiological solution, then incubated in Petri dishes containing the blood agar culture at 37°C for 48 h under microaerophilic conditions with 10% CO2. Then, after 48 h, specimens are prepared for scanning electron microscopy (SEM).

The CA measurements were performed on the basis of an average of three consecutive measurements of each sample according to a standard procedure with distilled water droplets, ethylene glycol and glycerol. CA measurements were made using the See System E instrument with Software 7.0, Advex Instrument. Measurements were performed on three types of samples, and the results were obtained by averaging three consecutive measurements of each sample according to the standard distilled water drop procedure.

Surface-free energy (SFE) calculations are performed according to the Owens–Wendt Regression model. For this purpose, CA measurements were performed on the basis of an average of three consecutive measurements of each sample according to a standard procedure with distilled water droplets, ethylene glycol and glycerol.

To observe the morphology of bacterial adhesion, specimens are prepared for SEM. The samples were fixed in 2% glutaraldehyde for 24 h at room temperature, washed three times with buffer phosphate solution (pH 7.4) and dehydrated through a series of sorted ethanol solutions (20%, 40%, 60%, 80% and 100%). The samples are then dried, coated with gold spray and scanned using an electron microscope VEGA3 LMU coupled with energy-dispersive X-ray spectroscopy (INCA Energy 250 Microanalysis System). The accelerating voltage of the SE detector was set to 20 kV.

XRPD analysis was performed on Rigaku Ultima IV X-ray diffractometer equipped with D/teX high-speed 1-dimensional detector using CuKα radiation (λ = 1.54178 Å) in 2θ range from 5° to 60°. The accelerating voltage and the current power were set to 40 kV and 40 mA, respectively.

The chemical compositions of the starting materials as provided by the producer for all three starting materials are shown below (Table 1).

Table 1

Chemical composition of starting materials

MaterialsManufacturerComposition
ZirconiumCeramill* Zolid fx white, GermanyY2O3 (9.15–9.55%), HfO2 (<5%), Al2O3 (<0.5), others (0.1%)
Metal alloyKera N, Eisenbacher-Dentalwaren ED-GMBH, GermanyNi (61.4%), Cr (25.9%), Mo (11%), Si (1.5%), others (<0.1%)
CompositesSr ADORO, Ivoclare Vivadent, LiechtensteinUretan dimetakrilat (UDMA), (SiO2, 70%)
  1. Ethical approval: The conducted research is not related to either human or animal use.

3 Results and discussion

3.1 XRPD analysis of the starting materials

The XRPD analysis (Figure 1a) shows the presence of amorphous phase present in the sample, manifested with a wide bump in the region 15–30° 2θ. This bump is due to the amorphous silica [18,19]. Evident is the presence of crystalline phases: quartz in the following 2θ 26.58° (d 3.35 Å), 50.10° (d 1.81 Å) and 59.70° (d 1.54 Å) [20,21]; peaks at 30.10° (d 2.96 Å) and 34.82° (d 2.57 Å) due to the presence of cubic zirconia. Figure 1b shows the presence of two peaks at 43.86° (d 2.06 Å) and 50.86° (d 1.79 Å) as a result of the Ni–Cr–Mo alloy present in the sample. Figure 1c depicts crystalline behavior of the sample manifested by the appearance of peaks characteristic for cubic zirconia as well as quartz peaks. The peaks at 2θ 20.92° (d 4.24 Å) and 26.70° (d 3.34 Å) are due to the presence of quartz, while 30.20° (d 2.95 Å), 35.06° (d 2.55 Å), 50.26° (d 1.81 Å), 59.82° (d 1.54 Å) and 62.72° (d 1.47 Å) are as a result of cubic zirconia [20,21,22].

Figure 1 XRPD of a – composite (Q – quartz, Z – zirconia), b – alloy (A – Ni–Cr–Mo alloy) and c – zirconium (Q – quartz, Z – zirconia).
Figure 1

XRPD of a – composite (Q – quartz, Z – zirconia), b – alloy (A – Ni–Cr–Mo alloy) and c – zirconium (Q – quartz, Z – zirconia).

3.2 CAs and free surface energy

Table 2 shows the results of the CA for the three tested samples (zirconium, alloy and composite). Based on the CA measurements, the following is observed: the highest CA is observed with zirconium sample. The CA of the metal alloy is characterized by a CA lower by 4.35% than the zirconium sample, while the CA of the composite material is characterized by an even lower angle by 3.04%. This observed difference is not statistically significant. Therefore, based on the measurements made, the following can be concluded: based on the CA measurements, it can be concluded that the most hydrophobic characteristics are the samples with ordinal numbers: 1, 3 and 2.

Table 2

CA of zirconium, metal alloy and composite

SpecimenCA (°)
Zirconium90.34
Metal alloy (Ni–Cr–Mo alloy)86.41
Composite87.59

Table 3 shows the results of the SFE of three tested samples subject of this in vitro study. The data obtained from the SFE according to the OWR model show highly significant differences among the different materials. From the measurements of the SFE, it can be concluded that the highest values show the samples in ordinal numbers: 3, 2 and 1. These results, especially the CA for the composite, are most likely due to the amorphous matter present in the sample (Figure 1a).

Table 3

SFE of zirconium, metal alloy and composite

SpecimenSFE according to OWR model [mJ/m2]
Zirconium24.31
Metal alloy (Ni–Cr–Mo alloy)31.78
Composite48.82

3.3 SEM analysis

The SEM micrographs of the surfaces of zirconium, metal alloy and the composite are shown in Figure 2. Based on the provided results, it is observed that the surfaces of all three materials are remarkably different. The composite seems to be with the smoothest surface, while zirconia has a rigid surface topography.

Figure 2 SEM micrographs of a – zirconia composite, b – metal alloy, c – composite.
Figure 2

SEM micrographs of a – zirconia composite, b – metal alloy, c – composite.

While surface morphology plays a crucial role in the process of bacterial adhesions; in this study, the opposite is observed. Although the rigidness of the surface of zirconia is clearly observable compared to the other two, yet the average number of bacteria is observed to be significantly higher in the composite material. Table 4 shows the results obtained based on the number of bacteria developed in all three specimens. It is evident that the number of bacteria in metal alloys is around 3.8 times higher than zirconia, while this number is around 4.5 times higher in the composite material.

Table 4

Number of bacteria in different specimens (zirconium, metal alloy and composite)

SpecimenNumber of bacteria
Zirconium17
Metal alloy (Ni–Cr–Mo alloy)65
Composite80

4 Conclusions

This in vitro study evaluated the bacterial adhesion of S. mutans to zirconia, nickel–chromium–molybdenum alloys and composite materials. The obtained results show different values of CA, free surface energy and bacterial adhesion for all three materials. No correlation was found between CA and bacterial adhesion, whereas SFE correlated with bacterial adhesion, so that with increasing free surface energy, the bacterial adhesion of S. mutans increased. The analysis of the susceptibility of the selected dental materials to the adhesion of microorganisms as part of this study showed that the composite material is more susceptible to the adhesion of microorganisms. The hydrophobicity of the surfaces shows no association with bacterial adhesion in the test materials, whereas the free surface energy is correlated with the bacterial adhesion of S. mutans. Differences in the adhesion of microorganisms to the surface zirconia vs composite were statistically significant. Based on the above-mentioned results, it can be concluded that zirconia as dental ceramics has the lowest values for the presence of bacteria, followed by nickel–chromium–molybdenum alloy, while the highest values are found in the composites.

Acknowledgment

The authors thank the Ministry of Education and Science of North Macedonia and the Chemists Society of Turkey and for providing the financial support. The authors also thank Professor Blazo Boev and Mr. sc. Maja Lazarova for their support during the process of characterization of the samples with SEM, and Professor Metodija Najdovski for performing the XRPD analysis.

  1. Conflict of interest: The authors declare no conflict of interest.

References

[1] Wassmann T, Kreis S, Behr M, Buergers R. The influence of surface texture and wettability on initial bacterial adhesion on titanium and zirconium oxide dental implants. Int J Implant Dent. 2017;3:32.10.1186/s40729-017-0093-3Search in Google Scholar

[2] Poon CY, Bhushan B. Comparison of surface roughness measurements by stylus profiler, AFM and non-contact profiler. Wear. 1995;190:76–88.10.1016/0043-1648(95)06697-7Search in Google Scholar

[3] Hahnel S, Rosentritt M, Handel G, Bürgers R. Surface characterization of dental ceramics and initial streptococcal adhesion in vitro. Dent Mater. 2009;25:969–75.10.1016/j.dental.2009.02.003Search in Google Scholar PubMed

[4] Abrahamsson I, Berglundh T, Lindhe J. Soft tissue response to plaque formation at different implant systems. A comparative study in the dog. Clin Oral Implants Res. 1998;9:73–9.10.1034/j.1600-0501.1998.090202.xSearch in Google Scholar PubMed

[5] Scarano A, Piattelli M, Caputi S, Favero GA, Piattelli A. Bacterial adhesion on commercially pure titanium and zirconium oxide disks: an in vivo human study. J Periodontol. 2004;75:292–6.10.1902/jop.2004.75.2.292Search in Google Scholar PubMed

[6] Elter C, Heuer W, Demling A, Hannig M, Heidenblut T, Bach FW. Supra and subgingival biofilm formation on implant abutments with different surface characteristics. Int J Oral Maxillofac Implants. 2008;23:327–34.Search in Google Scholar

[7] Oh TJ, Yoon J, Misch CE, Wang HL. The causes of early implant bone loss: myth or science? J Periodontol. 2002;73:322–33.10.1902/jop.2002.73.3.322Search in Google Scholar PubMed

[8] Mabbouxa F, Ponsonnetb L, Morriera J, Jaffrezicb N, Barsottia O. Surface free energy and bacterial retention to salivacoated dental implant materials – an in vitro study. Colloids Surf B. 2004;39:199–205.10.1016/j.colsurfb.2004.08.002Search in Google Scholar PubMed

[9] Lee BC, Jung GY, Kim DJ, Han JS. Initial bacterial adhesion on resin, titanium and zirconia in vitro. J Adv Prosthodont. 2011;3:81–4.10.4047/jap.2011.3.2.81Search in Google Scholar PubMed PubMed Central

[10] Soliman WE, Ali AI. Adhesion of Streptococcus mutans biofilm on the surface of indirect resin composites restoration. Int J Adv Res. 2017;5:1217–23.10.21474/IJAR01/3626Search in Google Scholar

[11] Fontana M, Gffel LE, Gregory RL. Characterization of preparations enriched for Streptococcus mutans fimbriae: salivary immunoglobulin A antibodies in caries-free and caries-active subjects. Clin Diagnolab Immunol. 1995;2:719–25.10.1128/cdli.2.6.719-725.1995Search in Google Scholar PubMed PubMed Central

[12] Van Brakel R, Cune MS, Van Winkelhoff AJ, De Putter C, Verhoeven JW, Van Der Reijden W. Early bacterial colonization and soft tissue health around zirconia and titanium abutments: an in vivo study in man. Clin Oral Implants Res. 2011;22:571–7.10.1111/j.1600-0501.2010.02005.xSearch in Google Scholar

[13] Al-Ahmad A, Wiedmann-Al-Ahmad M, Faust J, Bachle M, Follo M, Wolkewitz M. Biofilm formation and composition on different implant materials in vivo. J Biomed Mater Res B Appl Biomater. 2010;95:101–9.10.1002/jbm.b.31688Search in Google Scholar

[14] Teughels W, Van Assche N, Sliepen I, Quirynen M. Effect of material characteristics and/or surface topography on biofilm development. Clin Oral Implants Res. 2006;17:68–81.10.1111/j.1600-0501.2006.01353.xSearch in Google Scholar

[15] Quirynen M, Bollen CM. The influence of surface roughness and surface-free energy on supra and subgingival plaque formation in man, a review of the literature. J Clin Periodontol. 1995;22:1–14.10.1111/j.1600-051X.1995.tb01765.xSearch in Google Scholar

[16] Flemming HC, Wingender J. The biofilm matrix. Nat Rev Microbiol. 2010;8:623–33.10.1038/nrmicro2415Search in Google Scholar

[17] Aykent F, Gunal S, Avunduk M, Ozkan S. Effect of different finishing techniques for restorative materials on surface roughness and bacterial adhesion. J Prosthet Dent. 2010;103:221–7.10.1016/S0022-3913(10)60034-0Search in Google Scholar

[18] Reka AA, Anovski T, Bogoevski S, Pavlovski B, Boškovski B. Physical-chemical and mineralogical-petrographic examinations of diatomite from deposit near village of Rožden, Republic of Macedonia. Geologica Macedonica. 2014;28:121–6.Search in Google Scholar

[19] Reka AA, Pavlovski B, Makreski P. New optimized method for low-temperature hydrothermal production of porous ceramics using diatomaceous earth. Ceram Int. 2017;43:12572–78.10.1016/j.ceramint.2017.06.132Search in Google Scholar

[20] Reka AA, Pavlovski B, Ademi E, Jashari A, Boev B, Boev I, et al. Effect of thermal treatment of trepel at temperature range 800–1200°C. Open Chem. 2019;17:1235–43.10.1515/chem-2019-0132Search in Google Scholar

[21] Cekova B, Pavlovski B, Spasev D, Reka A. Structural examinations of natural raw materials pumice and trepel from Republic of Macedonia. Proceedings of the XV Balkan Mineral Processing Congress. Sozopol, Bulgaria; 2013. p. 73–75.Search in Google Scholar

[22] Reka AA, Pavlovski B, Cekova B. Special ceramics based on partially stabilized ZrO2. Proceedings Symposium of novel technologies and economic development; 2013. p. 73–81.Search in Google Scholar

Received: 2020-04-08
Revised: 2020-08-20
Accepted: 2020-08-21
Published Online: 2020-11-04

© 2020 Fuat Bislimi et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Regular Articles
  2. Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)
  3. Kinetic models of the extraction of vanillic acid from pumpkin seeds
  4. On the maximum ABC index of bipartite graphs without pendent vertices
  5. Estimation of the total antioxidant potential in the meat samples using thin-layer chromatography
  6. Molecular dynamics simulation of sI methane hydrate under compression and tension
  7. Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia
  8. Amino-functionalized graphene oxide for Cr(VI), Cu(II), Pb(II) and Cd(II) removal from industrial wastewater
  9. Chemical composition and in vitro activity of Origanum vulgare L., Satureja hortensis L., Thymus serpyllum L. and Thymus vulgaris L. essential oils towards oral isolates of Candida albicans and Candida glabrata
  10. Effect of excess Fluoride consumption on Urine-Serum Fluorides, Dental state and Thyroid Hormones among children in “Talab Sarai” Punjab Pakistan
  11. Design, Synthesis and Characterization of Novel Isoxazole Tagged Indole Hybrid Compounds
  12. Comparison of kinetic and enzymatic properties of intracellular phosphoserine aminotransferases from alkaliphilic and neutralophilic bacteria
  13. Green Organic Solvent-Free Oxidation of Alkylarenes with tert-Butyl Hydroperoxide Catalyzed by Water-Soluble Copper Complex
  14. Ducrosia ismaelis Asch. essential oil: chemical composition profile and anticancer, antimicrobial and antioxidant potential assessment
  15. DFT calculations as an efficient tool for prediction of Raman and infra-red spectra and activities of newly synthesized cathinones
  16. Influence of Chemical Osmosis on Solute Transport and Fluid Velocity in Clay Soils
  17. A New fatty acid and some triterpenoids from propolis of Nkambe (North-West Region, Cameroon) and evaluation of the antiradical scavenging activity of their extracts
  18. Antiplasmodial Activity of Stigmastane Steroids from Dryobalanops oblongifolia Stem Bark
  19. Rapid identification of direct-acting pancreatic protectants from Cyclocarya paliurus leaves tea by the method of serum pharmacochemistry combined with target cell extraction
  20. Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)
  21. Assessment of methyl 2-({[(4,6-dimethoxypyrimidin-2-yl)carbamoyl] sulfamoyl}methyl)benzoate through biotic and abiotic degradation modes
  22. Stability of natural polyphenol fisetin in eye drops Stability of fisetin in eye drops
  23. Production of a bioflocculant by using activated sludge and its application in Pb(II) removal from aqueous solution
  24. Molecular Properties of Carbon Crystal Cubic Structures
  25. Synthesis and characterization of calcium carbonate whisker from yellow phosphorus slag
  26. Study on the interaction between catechin and cholesterol by the density functional theory
  27. Analysis of some pharmaceuticals in the presence of their synthetic impurities by applying hybrid micelle liquid chromatography
  28. Two mixed-ligand coordination polymers based on 2,5-thiophenedicarboxylic acid and flexible N-donor ligands: the protective effect on periodontitis via reducing the release of IL-1β and TNF-α
  29. Incorporation of silver stearate nanoparticles in methacrylate polymeric monoliths for hemeprotein isolation
  30. Development of ultrasound-assisted dispersive solid-phase microextraction based on mesoporous carbon coated with silica@iron oxide nanocomposite for preconcentration of Te and Tl in natural water systems
  31. N,N′-Bis[2-hydroxynaphthylidene]/[2-methoxybenzylidene]amino]oxamides and their divalent manganese complexes: Isolation, spectral characterization, morphology, antibacterial and cytotoxicity against leukemia cells
  32. Determination of the content of selected trace elements in Polish commercial fruit juices and health risk assessment
  33. Diorganotin(iv) benzyldithiocarbamate complexes: synthesis, characterization, and thermal and cytotoxicity study
  34. Keratin 17 is induced in prurigo nodularis lesions
  35. Anticancer, antioxidant, and acute toxicity studies of a Saudi polyherbal formulation, PHF5
  36. LaCoO3 perovskite-type catalysts in syngas conversion
  37. Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity
  38. Fragmentation pattern of certain isatin–indole antiproliferative conjugates with application to identify their in vitro metabolic profiles in rat liver microsomes by liquid chromatography tandem mass spectrometry
  39. Investigation of polyphenol profile, antioxidant activity and hepatoprotective potential of Aconogonon alpinum (All.) Schur roots
  40. Lead discovery of a guanidinyl tryptophan derivative on amyloid cascade inhibition
  41. Physicochemical evaluation of the fruit pulp of Opuntia spp growing in the Mediterranean area under hard climate conditions
  42. Electronic structural properties of amino/hydroxyl functionalized imidazolium-based bromide ionic liquids
  43. New Schiff bases of 2-(quinolin-8-yloxy)acetohydrazide and their Cu(ii), and Zn(ii) metal complexes: their in vitro antimicrobial potentials and in silico physicochemical and pharmacokinetics properties
  44. Treatment of adhesions after Achilles tendon injury using focused ultrasound with targeted bFGF plasmid-loaded cationic microbubbles
  45. Synthesis of orotic acid derivatives and their effects on stem cell proliferation
  46. Chirality of β2-agonists. An overview of pharmacological activity, stereoselective analysis, and synthesis
  47. Fe3O4@urea/HITh-SO3H as an efficient and reusable catalyst for the solvent-free synthesis of 7-aryl-8H-benzo[h]indeno[1,2-b]quinoline-8-one and indeno[2′,1′:5,6]pyrido[2,3-d]pyrimidine derivatives
  48. Adsorption kinetic characteristics of molybdenum in yellow-brown soil in response to pH and phosphate
  49. Enhancement of thermal properties of bio-based microcapsules intended for textile applications
  50. Exploring the effect of khat (Catha edulis) chewing on the pharmacokinetics of the antiplatelet drug clopidogrel in rats using the newly developed LC-MS/MS technique
  51. A green strategy for obtaining anthraquinones from Rheum tanguticum by subcritical water
  52. Cadmium (Cd) chloride affects the nutrient uptake and Cd-resistant bacterium reduces the adsorption of Cd in muskmelon plants
  53. Removal of H2S by vermicompost biofilter and analysis on bacterial community
  54. Structural cytotoxicity relationship of 2-phenoxy(thiomethyl)pyridotriazolopyrimidines: Quantum chemical calculations and statistical analysis
  55. A self-breaking supramolecular plugging system as lost circulation material in oilfield
  56. Synthesis, characterization, and pharmacological evaluation of thiourea derivatives
  57. Application of drug–metal ion interaction principle in conductometric determination of imatinib, sorafenib, gefitinib and bosutinib
  58. Synthesis and characterization of a novel chitosan-grafted-polyorthoethylaniline biocomposite and utilization for dye removal from water
  59. Optimisation of urine sample preparation for shotgun proteomics
  60. DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases
  61. Treatment of Parkinson’s disease using focused ultrasound with GDNF retrovirus-loaded microbubbles to open the blood–brain barrier
  62. New derivatives of a natural nordentatin
  63. Fluorescence biomarkers of malignant melanoma detectable in urine
  64. Study of the remediation effects of passivation materials on Pb-contaminated soil
  65. Saliva proteomic analysis reveals possible biomarkers of renal cell carcinoma
  66. Withania frutescens: Chemical characterization, analgesic, anti-inflammatory, and healing activities
  67. Design, synthesis and pharmacological profile of (−)-verbenone hydrazones
  68. Synthesis of magnesium carbonate hydrate from natural talc
  69. Stability-indicating HPLC-DAD assay for simultaneous quantification of hydrocortisone 21 acetate, dexamethasone, and fluocinolone acetonide in cosmetics
  70. A novel lactose biosensor based on electrochemically synthesized 3,4-ethylenedioxythiophene/thiophene (EDOT/Th) copolymer
  71. Citrullus colocynthis (L.) Schrad: Chemical characterization, scavenging and cytotoxic activities
  72. Development and validation of a high performance liquid chromatography/diode array detection method for estrogen determination: Application to residual analysis in meat products
  73. PCSK9 concentrations in different stages of subclinical atherosclerosis and their relationship with inflammation
  74. Development of trace analysis for alkyl methanesulfonates in the delgocitinib drug substance using GC-FID and liquid–liquid extraction with ionic liquid
  75. Electrochemical evaluation of the antioxidant capacity of natural compounds on glassy carbon electrode modified with guanine-, polythionine-, and nitrogen-doped graphene
  76. A Dy(iii)–organic framework as a fluorescent probe for highly selective detection of picric acid and treatment activity on human lung cancer cells
  77. A Zn(ii)–organic cage with semirigid ligand for solvent-free cyanosilylation and inhibitory effect on ovarian cancer cell migration and invasion ability via regulating mi-RNA16 expression
  78. Polyphenol content and antioxidant activities of Prunus padus L. and Prunus serotina L. leaves: Electrochemical and spectrophotometric approach and their antimicrobial properties
  79. The combined use of GC, PDSC and FT-IR techniques to characterize fat extracted from commercial complete dry pet food for adult cats
  80. MALDI-TOF MS profiling in the discovery and identification of salivary proteomic patterns of temporomandibular joint disorders
  81. Concentrations of dioxins, furans and dioxin-like PCBs in natural animal feed additives
  82. Structure and some physicochemical and functional properties of water treated under ammonia with low-temperature low-pressure glow plasma of low frequency
  83. Mesoscale nanoparticles encapsulated with emodin for targeting antifibrosis in animal models
  84. Amine-functionalized magnetic activated carbon as an adsorbent for preconcentration and determination of acidic drugs in environmental water samples using HPLC-DAD
  85. Antioxidant activity as a response to cadmium pollution in three durum wheat genotypes differing in salt-tolerance
  86. A promising naphthoquinone [8-hydroxy-2-(2-thienylcarbonyl)naphtho[2,3-b]thiophene-4,9-dione] exerts anti-colorectal cancer activity through ferroptosis and inhibition of MAPK signaling pathway based on RNA sequencing
  87. Synthesis and efficacy of herbicidal ionic liquids with chlorsulfuron as the anion
  88. Effect of isovalent substitution on the crystal structure and properties of two-slab indates BaLa2−xSmxIn2O7
  89. Synthesis, spectral and thermo-kinetics explorations of Schiff-base derived metal complexes
  90. An improved reduction method for phase stability testing in the single-phase region
  91. Comparative analysis of chemical composition of some commercially important fishes with an emphasis on various Malaysian diets
  92. Development of a solventless stir bar sorptive extraction/thermal desorption large volume injection capillary gas chromatographic-mass spectrometric method for ultra-trace determination of pyrethroids pesticides in river and tap water samples
  93. A turbidity sensor development based on NL-PI observers: Experimental application to the control of a Sinaloa’s River Spirulina maxima cultivation
  94. Deep desulfurization of sintering flue gas in iron and steel works based on low-temperature oxidation
  95. Investigations of metallic elements and phenolics in Chinese medicinal plants
  96. Influence of site-classification approach on geochemical background values
  97. Effects of ageing on the surface characteristics and Cu(ii) adsorption behaviour of rice husk biochar in soil
  98. Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils
  99. Antimicrobial and antifungal activities of bifunctional cooper(ii) complexes with non-steroidal anti-inflammatory drugs, flufenamic, mefenamic and tolfenamic acids and 1,10-phenanthroline
  100. Application of selenium and silicon to alleviate short-term drought stress in French marigold (Tagetes patula L.) as a model plant species
  101. Screening and analysis of xanthine oxidase inhibitors in jute leaves and their protective effects against hydrogen peroxide-induced oxidative stress in cells
  102. Synthesis and physicochemical studies of a series of mixed-ligand transition metal complexes and their molecular docking investigations against Coronavirus main protease
  103. A study of in vitro metabolism and cytotoxicity of mephedrone and methoxetamine in human and pig liver models using GC/MS and LC/MS analyses
  104. A new phenyl alkyl ester and a new combretin triterpene derivative from Combretum fragrans F. Hoffm (Combretaceae) and antiproliferative activity
  105. Erratum
  106. Erratum to: A one-step incubation ELISA kit for rapid determination of dibutyl phthalate in water, beverage and liquor
  107. Review Articles
  108. Sinoporphyrin sodium, a novel sensitizer for photodynamic and sonodynamic therapy
  109. Natural products isolated from Casimiroa
  110. Plant description, phytochemical constituents and bioactivities of Syzygium genus: A review
  111. Evaluation of elastomeric heat shielding materials as insulators for solid propellant rocket motors: A short review
  112. Special Issue on Applied Biochemistry and Biotechnology 2019
  113. An overview of Monascus fermentation processes for monacolin K production
  114. Study on online soft sensor method of total sugar content in chlorotetracycline fermentation tank
  115. Studies on the Anti-Gouty Arthritis and Anti-hyperuricemia Properties of Astilbin in Animal Models
  116. Effects of organic fertilizer on water use, photosynthetic characteristics, and fruit quality of pear jujube in northern Shaanxi
  117. Characteristics of the root exudate release system of typical plants in plateau lakeside wetland under phosphorus stress conditions
  118. Characterization of soil water by the means of hydrogen and oxygen isotope ratio at dry-wet season under different soil layers in the dry-hot valley of Jinsha River
  119. Composition and diurnal variation of floral scent emission in Rosa rugosa Thunb. and Tulipa gesneriana L.
  120. Preparation of a novel ginkgolide B niosomal composite drug
  121. The degradation, biodegradability and toxicity evaluation of sulfamethazine antibiotics by gamma radiation
  122. Special issue on Monitoring, Risk Assessment and Sustainable Management for the Exposure to Environmental Toxins
  123. Insight into the cadmium and zinc binding potential of humic acids derived from composts by EEM spectra combined with PARAFAC analysis
  124. Source apportionment of soil contamination based on multivariate receptor and robust geostatistics in a typical rural–urban area, Wuhan city, middle China
  125. Special Issue on 13th JCC 2018
  126. The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide
  127. Preparation of magnetite-silica–cetyltrimethylammonium for phenol removal based on adsolubilization
  128. Topical Issue on Agriculture
  129. Size-dependent growth kinetics of struvite crystals in wastewater with calcium ions
  130. The effect of silica-calcite sedimentary rock contained in the chicken broiler diet on the overall quality of chicken muscles
  131. Physicochemical properties of selected herbicidal products containing nicosulfuron as an active ingredient
  132. Lycopene in tomatoes and tomato products
  133. Fluorescence in the assessment of the share of a key component in the mixing of feed
  134. Sulfur application alleviates chromium stress in maize and wheat
  135. Effectiveness of removal of sulphur compounds from the air after 3 years of biofiltration with a mixture of compost soil, peat, coconut fibre and oak bark
  136. Special Issue on the 4th Green Chemistry 2018
  137. Study and fire test of banana fibre reinforced composites with flame retardance properties
  138. Special Issue on the International conference CosCI 2018
  139. Disintegration, In vitro Dissolution, and Drug Release Kinetics Profiles of k-Carrageenan-based Nutraceutical Hard-shell Capsules Containing Salicylamide
  140. Synthesis of amorphous aluminosilicate from impure Indonesian kaolin
  141. Special Issue on the International Conf on Science, Applied Science, Teaching and Education 2019
  142. Functionalization of Congo red dye as a light harvester on solar cell
  143. The effect of nitrite food preservatives added to se’i meat on the expression of wild-type p53 protein
  144. Biocompatibility and osteoconductivity of scaffold porous composite collagen–hydroxyapatite based coral for bone regeneration
  145. Special Issue on the Joint Science Congress of Materials and Polymers (ISCMP 2019)
  146. Effect of natural boron mineral use on the essential oil ratio and components of Musk Sage (Salvia sclarea L.)
  147. A theoretical and experimental study of the adsorptive removal of hexavalent chromium ions using graphene oxide as an adsorbent
  148. A study on the bacterial adhesion of Streptococcus mutans in various dental ceramics: In vitro study
  149. Corrosion study of copper in aqueous sulfuric acid solution in the presence of (2E,5E)-2,5-dibenzylidenecyclopentanone and (2E,5E)-bis[(4-dimethylamino)benzylidene]cyclopentanone: Experimental and theoretical study
  150. Special Issue on Chemistry Today for Tomorrow 2019
  151. Diabetes mellitus type 2: Exploratory data analysis based on clinical reading
  152. Multivariate analysis for the classification of copper–lead and copper–zinc glasses
  153. Special Issue on Advances in Chemistry and Polymers
  154. The spatial and temporal distribution of cationic and anionic radicals in early embryo implantation
  155. Special Issue on 3rd IC3PE 2020
  156. Magnetic iron oxide/clay nanocomposites for adsorption and catalytic oxidation in water treatment applications
  157. Special Issue on IC3PE 2018/2019 Conference
  158. Exergy analysis of conventional and hydrothermal liquefaction–esterification processes of microalgae for biodiesel production
  159. Advancing biodiesel production from microalgae Spirulina sp. by a simultaneous extraction–transesterification process using palm oil as a co-solvent of methanol
  160. Topical Issue on Applications of Mathematics in Chemistry
  161. Omega and the related counting polynomials of some chemical structures
  162. M-polynomial and topological indices of zigzag edge coronoid fused by starphene
Downloaded on 19.12.2025 from https://www.degruyterbrill.com/document/doi/10.1515/chem-2020-0070/html
Scroll to top button