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1.
Int J Mol Sci ; 25(19)2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39408866

ABSTRACT

Cancer therapy is constantly evolving, with a growing emphasis on targeted and efficient treatment options. In this context, graphene quantum dots (GQDs) have emerged as promising agents for precise drug and gene delivery due to their unique attributes, such as high surface area, photoluminescence, up-conversion photoluminescence, and biocompatibility. GQDs can damage cancer cells and exhibit intrinsic photothermal conversion and singlet oxygen generation efficiency under specific light irradiation, enhancing their effectiveness. They serve as direct therapeutic agents and versatile drug delivery platforms capable of being easily functionalized with various targeting molecules and therapeutic agents. However, challenges such as achieving uniform size and morphology, precise bandgap engineering, and scalability, along with minimizing cytotoxicity and the environmental impact of their production, must be addressed. Additionally, there is a need for a more comprehensive understanding of cellular mechanisms and drug release processes, as well as improved purification methods. Integrating GQDs into existing drug delivery systems enhances the efficacy of traditional treatments, offering more efficient and less invasive options for cancer patients. This review highlights the transformative potential of GQDs in cancer therapy while acknowledging the challenges that researchers must overcome for broader application.


Subject(s)
Drug Delivery Systems , Gene Transfer Techniques , Graphite , Neoplasms , Quantum Dots , Quantum Dots/chemistry , Graphite/chemistry , Humans , Neoplasms/therapy , Neoplasms/drug therapy , Neoplasms/genetics , Drug Delivery Systems/methods , Carbon/chemistry , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry
2.
Nanotechnology ; 36(2)2024 Oct 21.
Article in English | MEDLINE | ID: mdl-39389086

ABSTRACT

Reduced graphene oxide (rGO) has unique physicochemical properties that make it suitable for therapeutic applications in neurodegenerative scenarios. This study investigates the therapeutic potential of rGO in a cuprizone-induced demyelination model in mice through histomorphological techniques and analysis of biochemical parameters. We demonstrate that daily intraperitoneal administration of rGO (1 mg ml-1) for 21 days tends to reduce demyelination in theCorpus callosumby decreasing glial cell recruitment during the repair mechanism. Additionally, rGO interferes with oxidative stress markers in the brain and liver indicating potential neuroprotective effects in the central nervous system. No significant damage to vital organs was observed, suggesting that multiple doses could be used safely. However, further long-term investigations are needed to understand rGO distribution, metabolism, routes of action and associated challenges in central neurodegenerative therapies. Overall, these findings contribute to the comprehension of rGO effectsin vivo, paving the way for possible future clinical research.


Subject(s)
Cuprizone , Demyelinating Diseases , Graphite , Oxidative Stress , Animals , Graphite/chemistry , Demyelinating Diseases/chemically induced , Demyelinating Diseases/drug therapy , Demyelinating Diseases/pathology , Mice , Oxidative Stress/drug effects , Male , Neuroprotective Agents/pharmacology , Neuroprotective Agents/chemistry , Brain/pathology , Brain/drug effects , Brain/metabolism , Disease Models, Animal , Mice, Inbred C57BL , Liver/drug effects , Liver/pathology , Liver/metabolism , Corpus Callosum/drug effects , Corpus Callosum/pathology , Corpus Callosum/metabolism
3.
Environ Sci Pollut Res Int ; 31(44): 55958-55973, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39251534

ABSTRACT

Advanced oxidation processes (AOP) stood out as an efficient alternative for the treatment of organic contaminants. In this work, there were proposed syntheses of mixed catalysts of pyrite and graphene oxide and pyrite and zinc oxide to treat a mixture of the drugs atenolol and propranolol in aqueous solution through the photo-Fenton process with ultraviolet radiation. The efficiency of the methodologies used in the syntheses was confirmed through different characterization analyses. It was verified that the pyrite and zinc oxide catalyst led to the best contaminant degradation percentages with values equal to 88 and 84% for the groups monitored at the wavelengths (λ) of 217 and 281 nm. The degradation kinetics presented a good fit to the kinetic model proposed by Chan and Chu (2003) with R2 equal to 0.99, indicating a pseudo-first-order degradation profile. Finally, toxicity tests were carried out with two types of seeds, watercress and cabbage, for the solution before and after treatment. The cabbage seeds showed a reduction in germination percentages for the samples after treatments, while no toxicity was observed for watercress ones. This highlights the importance of evaluating the implications caused by products in relation to different organisms representing the biota.


Subject(s)
Graphite , Oxidation-Reduction , Zinc Oxide , Graphite/chemistry , Catalysis , Zinc Oxide/chemistry , Sulfides/chemistry , Water Pollutants, Chemical/chemistry , Iron/chemistry , Kinetics
4.
Biomater Sci ; 12(21): 5547-5561, 2024 Oct 22.
Article in English | MEDLINE | ID: mdl-39292186

ABSTRACT

Carbon-derived compounds are gaining traction in the scientific community because of their unique properties, such as conductivity and strength, and promising innovations in technology and medicine. Graphitic nitride carbon (g-C3N4) stands out among these compounds because of its potential in antitumor therapies. This study aimed to assess g-C3N4's antitumor potential and cytotoxic mechanisms. Prostate cancer (DU-145) and glioblastoma (U87) cell lines were used to evaluate antitumor effects, whereas RAW 264.7 and HFF-1 non-tumor cells were used for selectivity evaluation. The synthesized g-C3N4 particles underwent comprehensive characterization, including the assessment of particle size, morphology, and oxygen content, employing various techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The results indicated that g-C3N4 significantly affected tumor cell proliferation and viability, exhibiting high cytotoxicity within 48 h. In non-tumor cells, minimal effects on proliferation were observed, except for damage to the cell membranes of RAW 264.7 cells. Moreover, g-C3N4 changed the cell morphology and ultrastructure, affecting cell migration in U87 cells and potentially enhancing migration in RAW 264.7 cells. Biochemical assays in Balb/C mice revealed alterations in alanine aminotransferase, aspartate aminotransferase, and amylase levels. In conclusion, g-C3N4 demonstrated promising antitumor effects with minimal toxicity to non-tumor cells, suggesting its potential in neoplasm treatment.


Subject(s)
Antineoplastic Agents , Cell Proliferation , Glioblastoma , Graphite , Nitrogen Compounds , Prostatic Neoplasms , Graphite/chemistry , Graphite/pharmacology , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/administration & dosage , Male , Animals , Mice , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/pathology , Glioblastoma/drug therapy , Glioblastoma/pathology , Glioblastoma/metabolism , Nitrogen Compounds/chemistry , Nitrogen Compounds/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , RAW 264.7 Cells , Cell Survival/drug effects , Cell Movement/drug effects
5.
Anal Methods ; 16(40): 6793-6801, 2024 Oct 17.
Article in English | MEDLINE | ID: mdl-39248289

ABSTRACT

Laser scribing is a promising technology for the rapid and large-scale production of low-cost electrochemical sensors from diverse substrates. Polyimide has been the most popular so far because of its low cost, flexibility and capability of generating high-quality porous graphene films, known as laser-induced graphene (LIG). Herein we report the electrochemistry of chloramphenicol (CAP) on LIG electrodes and its determination in honey samples. LIG electrodes were fabricated by the photothermal conversion of sp3 carbon within the polymeric matrix into sp2 carbon using a CO2 laser cutter. The LIG electrode associated with differential pulse voltammetry (DPV) showed good linearity (R2 > 0.99) in the range from 10 to 160 µmol L-1 with a limit of detection of 1.0 µmol L-1 and good precision (RSD < 5%) for the electrochemical reduction of CAP species. Detection was possible free from the interference of other antibiotics, such as amoxicillin, tetracycline, sulfanilamide, and sulfamethoxazole. Spiked honey samples were analyzed by the standard-addition method and recovery values between 86 and 109% were obtained, which confirmed the absence of sample matrix effects. Therefore, the proposed sensor is an alternative, feasible, low-cost, and powerful analytical tool for the determination of CAP in honey.


Subject(s)
Chloramphenicol , Electrochemical Techniques , Electrodes , Graphite , Honey , Honey/analysis , Graphite/chemistry , Chloramphenicol/analysis , Chloramphenicol/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Lasers , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/chemistry , Limit of Detection
6.
Int J Mol Sci ; 25(18)2024 Sep 11.
Article in English | MEDLINE | ID: mdl-39337305

ABSTRACT

Graphene nanoplatelets (UGZ-1004) are emerging as a promising biomaterial in regenerative medicine. This study comprehensively evaluates UGZ-1004, focusing on its physical properties, cytotoxicity, intracellular interactions, and, notably, its effects on mesenchymal stem cells (MSCs). UGZ-1004 was characterized by lateral dimensions and layer counts consistent with ISO standards and demonstrated a high carbon purity of 0.08%. Cytotoxicity assessments revealed that UGZ-1004 is non-toxic to various cell lines, including 3T3 fibroblasts, VERO kidney epithelial cells, BV-2 microglia, and MSCs, in accordance with ISO 10993-5:2020/2023 guidelines. The study focused on MSCs and revealed that UGZ-1004 supports their gene expression alterations related to self-renewal and proliferation. MSCs exposed to UGZ-1004 maintained their characteristic surface markers. Importantly, UGZ-1004 promoted significant upregulation of genes crucial for cell cycle regulation and DNA repair, such as CDK1, CDK2, and MDM2. This gene expression profile suggests that UGZ-1004 can enhance MSC self-renewal capabilities, ensuring robust cellular function and longevity. Moreover, UGZ-1004 exposure led to the downregulation of genes associated with tumor development, including CCND1 and TFDP1, mitigating potential tumorigenic risks. These findings underscore the potential of UGZ-1004 to not only bolster MSC proliferation but also enhance their self-renewal processes, which are critical for effective regenerative therapies. The study highlights the need for continued research into the long-term impacts of graphene nanoplatelets and their application in MSC-based regenerative medicine.


Subject(s)
Cell Proliferation , Graphite , Mesenchymal Stem Cells , Cell Proliferation/drug effects , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/cytology , Animals , Graphite/chemistry , Graphite/pharmacology , Mice , Chlorocebus aethiops , Cell Self Renewal/drug effects , Cell Self Renewal/genetics , Vero Cells , Gene Expression Regulation/drug effects , Nanoparticles/chemistry , Cell Line , Nanostructures/chemistry
7.
Anal Bioanal Chem ; 416(24): 5233-5253, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39158631

ABSTRACT

Liquid chromatography-mass spectrometry (LC-MS) has emerged as a powerful analytical technique for analyzing complex biological samples. Among various chromatographic stationary phases, porous graphitic carbon (PGC) columns have attracted significant attention due to their unique properties-such as the ability to separate both polar and non-polar compounds and their stability through all pH ranges and to high temperatures-besides the compatibility with LC-MS. This review discusses the applicability of PGC for SPE and separation in LC-MS-based analyses of human biological samples, highlighting the diverse applications of PGC-LC-MS in analyzing endogenous metabolites, pharmaceuticals, and biomarkers, such as glycans, proteins, oligosaccharides, sugar phosphates, and nucleotides. Additionally, the fundamental principles underlying PGC column chemistry and its advantages, challenges, and advances in method development are explored. This comprehensive review aims to provide researchers and practitioners with a valuable resource for understanding the capabilities and limitations of PGC columns in LC-MS-based analysis of human biological samples, thereby facilitating advancements in analytical methodologies and biomedical research.


Subject(s)
Graphite , Mass Spectrometry , Humans , Graphite/chemistry , Chromatography, Liquid/methods , Porosity , Mass Spectrometry/methods , Solid Phase Extraction/methods , Biomarkers/analysis , Proteins/analysis , Polysaccharides/analysis , Liquid Chromatography-Mass Spectrometry
8.
Anal Methods ; 16(35): 6011-6019, 2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39171860

ABSTRACT

The potential impact on human health and the environment has spurred significant interest in detecting and quantifying pharmaceutical compounds across various matrices, from environmental to biological samples. Here, we present an electrochemical approach for determining levofloxacin in drug, synthetic urine, water, and breast milk samples. An affordable sensor was constructed using 3D printing and composite material based on nail polish, graphite, and aluminum oxide. The conductive composite material was characterized spectroscopically, electrochemically, and by imaging techniques. Subsequently, an electrochemical method based on square wave voltammetry was optimized and applied. The method exhibited good sensitivity (5.11 ± 0.0912 µA L µmol-1 cm-2) and enhanced stability (RSD = 7.2%), with electrochemical responses correlating with the concentration of levofloxacin in the samples tested, yielding recovery values in the range of 98 to 111%. The developed method demonstrated a robust linear working range from 2 to 100 µmol L-1 and a nanomolar detection limit of 128 nmol L-1, rendering it suitable for quantitative analysis. The sensor also shows promise as a platform for the sensitive detection of pharmaceutical compounds, contributing to greater safety and sustainability in these domains.


Subject(s)
Aluminum Oxide , Electrochemical Techniques , Electrodes , Graphite , Levofloxacin , Graphite/chemistry , Levofloxacin/analysis , Humans , Aluminum Oxide/chemistry , Electrochemical Techniques/methods , Electrochemical Techniques/instrumentation , Limit of Detection , Cost-Benefit Analysis , Printing, Three-Dimensional , Nails/chemistry , Anti-Bacterial Agents/analysis
9.
Int J Artif Organs ; 47(8): 633-641, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39113566

ABSTRACT

Cardiovascular diseases, particularly myocardial infarction, have significant healthcare challenges due to the limited regenerative capacity of injured heart tissue. Cardiac tissue engineering (CTE) offers a promising approach to repairing myocardial damage using biomaterials that mimic the heart's extracellular matrix. This study investigates the potential of graphene nanopowder (Gnp)-enhanced polycaprolactone (PCL) scaffolds fabricated via electrospinning to improve the properties necessary for effective cardiac repair. This work aimed to analyze scaffolds with varying graphene concentrations (0.5%, 1%, 1.5%, and 2% by weight) to determine their morphological, chemical, mechanical, and biocompatibility characteristics. The results presented that incorporating graphene improves PCL scaffolds' mechanical properties and cellular interactions. The optimal concentration of 1% graphene significantly enhanced mechanical properties and biocompatibility, promoting cell adhesion and proliferation. These findings suggest that Gnp-enhanced PCL scaffolds at this concentration can serve as a potent substrate for CTE providing insights into designing more effective biomaterials for myocardial restoration.


Subject(s)
Cell Proliferation , Graphite , Nanofibers , Polyesters , Tissue Engineering , Tissue Scaffolds , Tissue Engineering/methods , Graphite/chemistry , Polyesters/chemistry , Cell Proliferation/drug effects , Biocompatible Materials , Cell Adhesion/drug effects , Materials Testing , Animals , Myocytes, Cardiac/drug effects , Humans , Myocardium/pathology
10.
Bioelectrochemistry ; 160: 108795, 2024 Dec.
Article in English | MEDLINE | ID: mdl-39146929

ABSTRACT

E6 and E7 oncogenes are pivotal in the carcinogenic transformation in HPV infections and efficient diagnostic methods can ensure the detection and differentiation of HPV genotype. This study describes the development and validation of an electrochemical, label-free genosensor coupled with a microfluidic system for detecting the E6 and E7 oncogenes in cervical scraping samples. The nanostructuring employed was based on a cysteine and graphene quantum dots layer that provides functional groups, surface area, and interesting electrochemical properties. Biorecognition tests with cervical scraping samples showed differentiation in the voltammetric response. Low-risk HPV exhibited a lower biorecognition response, reflected in ΔI% values of 82.33 % ± 0.29 for HPV06 and 80.65 % ± 0.68 for HPV11 at a dilution of 1:100. Meanwhile, high-risk, HPV16 and HPV18, demonstrated ΔI% values of 96.65 % ± 1.27 and 93 % ± 0.026, respectively, at the same dilution. Therefore, the biorecognition intensity followed the order: HPV16 >HPV18 >HPV06 >HPV11. The limit of detection and the limit of quantification of E6E7 microfluidic LOC-Genosensor was 26 fM, and 79.6 fM. Consequently, the E6E7 biosensor is a valuable alternative for clinical HPV diagnosis, capable of detecting the potential for oncogenic progression even in the early stages of infection.


Subject(s)
Biosensing Techniques , Oncogene Proteins, Viral , Biosensing Techniques/methods , Humans , Oncogene Proteins, Viral/genetics , Female , Limit of Detection , Papillomavirus E7 Proteins/genetics , Cervix Uteri/virology , Graphite/chemistry , Papillomavirus Infections/diagnosis , Papillomavirus Infections/virology , Electrochemical Techniques/methods , Repressor Proteins/genetics , Microfluidic Analytical Techniques/methods , Microfluidic Analytical Techniques/instrumentation , Quantum Dots/chemistry , Lab-On-A-Chip Devices , Papillomaviridae/genetics , Papillomaviridae/isolation & purification
11.
Sensors (Basel) ; 24(15)2024 Aug 04.
Article in English | MEDLINE | ID: mdl-39124094

ABSTRACT

Graphene-based surface plasmon resonance (SPR) biosensors have emerged as a promising technology for the highly sensitive and accurate detection of biomolecules. This study presents a comprehensive theoretical analysis of graphene-based SPR biosensors, focusing on configurations with single and bimetallic metallic layers. In this study, we investigated the impact of various metallic substrates, including gold and silver, and the number of graphene layers on key performance metrics: sensitivity of detection, detection accuracy, and quality factor. Our findings reveal that configurations with graphene first supported on gold exhibit superior performance, with sensitivity of detection enhancements up to 30% for ten graphene layers. In contrast, silver-supported configurations, while demonstrating high sensitivity, face challenges in maintaining detection accuracy. Additionally, reducing the thickness of metallic layers by 30% optimizes light coupling and enhances sensor performance. These insights highlight the significant potential of graphene-based SPR biosensors in achieving high sensitivity of detection and reliability, paving the way for their application in diverse biosensing technologies. Our findings pretend to motivate future research focusing on optimizing metallic layer thickness, improving the stability of silver-supported configurations, and experimentally validating the theoretical findings to further advance the development of high-performance SPR biosensors.


Subject(s)
Biosensing Techniques , Gold , Graphite , Silver , Surface Plasmon Resonance , Graphite/chemistry , Surface Plasmon Resonance/methods , Silver/chemistry , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Gold/chemistry
12.
Braz J Biol ; 84: e279967, 2024.
Article in English | MEDLINE | ID: mdl-39140500

ABSTRACT

Scaffolds are 3D biomaterials that provide an environment for cell regeneration. In the context of bone remodeling, poly(e-caprolactone) (PCL) combined with graphene has been developed as the scaffold. It is imperative for scaffolds to possess antibacterial properties in order to properly reduce the risk of potential infections.Therefore, this study aims to analyze the antibacterial characteristics of PCL/graphene scaffolds against Staphylococcus aureus (S. aureus) and Porphyromonas gingivalis (P. gingivalis) in vitro. In this study, five different groups were used, including PCL (K-), Amoxicillin (K+), PCL/Graphene 0.5 wt%, PCL/graphene 1 wt% and PCL/Graphene 1.5 wt%. All experiments were performed in triplicates and were repeated three times, and the diffusion method by Kirby-Bauer test was used. The disc was incubated with S. aureus and P. gingivalis for 24 hours and then the diameter of the inhibition zone was measured. The results showed that the PCL/graphene scaffolds exhibited dose-dependent antibacterial activity against S. aureus and P. gingivalis. The inhibition zone diameter (IZD) against S. aureus of PCL/graphene 1 wt% was 9.53 ± 0.74 mm, and increased to 11.93 ± 0.92 mm at a concentration of 1.5 wt% of graphene. The PCL/graphene scaffold with 1.5 wt% exhibited a greater inhibitory effect, with an IZD of 12.56 ± 0.06 mm against P. gingivalis, while the inhibitory activity of the 1 wt% variant was relatively lower at 10.46 ± 0.24 mm. The negative control, PCL, and PCL/graphene 0.5 wt% exhibited no antibacterial activity sequentially (p = 1). Scaffolds of poly(e-caprolactone)/graphene exhibited an antibacterial activity at 1, and 1.5 wt% on S. aureus and P. gingivalis. The antibacterial properties of this scaffold make it a promising candidate for regenerating bone tissue.


Subject(s)
Anti-Bacterial Agents , Graphite , Polyesters , Porphyromonas gingivalis , Staphylococcus aureus , Tissue Scaffolds , Graphite/chemistry , Graphite/pharmacology , Porphyromonas gingivalis/drug effects , Staphylococcus aureus/drug effects , Tissue Scaffolds/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Polyesters/chemistry , Polyesters/pharmacology , Bone Regeneration/drug effects , Biocompatible Materials/pharmacology , Biocompatible Materials/chemistry , Microbial Sensitivity Tests
13.
Biosensors (Basel) ; 14(8)2024 Aug 16.
Article in English | MEDLINE | ID: mdl-39194623

ABSTRACT

Herein, we present a novel approach to quantify ferritin based on the integration of an Enzyme-Linked Immunosorbent Assay (ELISA) protocol on a Graphene Field-Effect Transistor (gFET) for bioelectronic immunosensing. The G-ELISA strategy takes advantage of the gFET inherent capability of detecting pH changes for the amplification of ferritin detection using urease as a reporter enzyme, which catalyzes the hydrolysis of urea generating a local pH increment. A portable field-effect transistor reader and electrolyte-gated gFET arrangement are employed, enabling their operation in aqueous conditions at low potentials, which is crucial for effective biological sample detection. The graphene surface is functionalized with monoclonal anti-ferritin antibodies, along with an antifouling agent, to enhance the assay specificity and sensitivity. Markedly, G-ELISA exhibits outstanding sensing performance, reaching a lower limit of detection (LOD) and higher sensitivity in ferritin quantification than unamplified gFETs. Additionally, they offer rapid detection, capable of measuring ferritin concentrations in approximately 50 min. Because of the capacity of transistor miniaturization, our innovative G-ELISA approach holds promise for the portable bioelectronic detection of multiple biomarkers using a small amount of the sample, which would be a great advancement in point-of-care testing.


Subject(s)
Biosensing Techniques , Enzyme-Linked Immunosorbent Assay , Ferritins , Graphite , Transistors, Electronic , Ferritins/analysis , Graphite/chemistry , Limit of Detection , Humans
14.
Sci Rep ; 14(1): 18916, 2024 08 14.
Article in English | MEDLINE | ID: mdl-39143177

ABSTRACT

The global concern over water pollution caused by contaminants of emerging concern has been the subject of several studies due to the complexity of treatment. Here, the synthesis of a graphene oxide-based magnetic material (GO@Fe3O4) produced according to a modified Hummers' method followed by a hydrothermal reaction was proposed; then, its application as a photocatalyst in clonazepam photo-Fenton degradation was investigated. Several characterization analyses were performed to analyze the structure, functionalization and magnetic properties of the composite. A 23 factorial design was used for the optimization procedure to investigate the effect of [H2O2], GO@Fe3O4 dose and pH on clonazepam degradation. Adsorption experiments demonstrated that GO@Fe3O4 could not adsorb clonazepam. Photo-Fenton kinetics showed that total degradation of clonazepam was achieved within 5 min, and the experimental data were better fitted to the PFO model. A comparative study of clonazepam degradation by different processes highlighted that the heterogeneous photo-Fenton process was more efficient than homogeneous processes. The radical scavenging test showed that O 2 · - was the main active free radical in the degradation reaction, followed by hydroxyl radicals (•OH) and holes (h+) in the valence layer; accordingly, a mechanism of degradation was proposed to describe the process.


Subject(s)
Clonazepam , Graphite , Photolysis , Water Pollutants, Chemical , Graphite/chemistry , Clonazepam/chemistry , Water Pollutants, Chemical/chemistry , Hydrogen Peroxide/chemistry , Adsorption , Water Purification/methods , Kinetics
15.
ACS Appl Bio Mater ; 7(8): 5530-5540, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-39093994

ABSTRACT

This study reports on the modification of bacterial cellulose (BC) membranes produced by static fermentation of Komagataeibacter xylinus bacterial strains with graphene oxide-silver nanoparticles (GO-Ag) to yield skin wound dressings with improved antibacterial properties. The GO-Ag sheets were synthesized through chemical reduction with sodium citrate and were utilized to functionalize the BC membranes (BC/GO-Ag). The BC/GO-Ag composites were characterized to determine their surface charge, morphology, exudate absorption, antimicrobial activity, and cytotoxicity by using fibroblast cells. The antimicrobial activity of the wound dressings was assessed against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The results indicate that the BC/GO-Ag dressings can inhibit ∼70% of E. coli cells. Our findings also revealed that the porous BC/GO-Ag antimicrobial dressings can efficiently retain 94% of exudate absorption after exposure to simulated body fluid (SBF) for 24 h. These results suggest that the dressings could absorb excess exudate from the wound during clinical application, maintaining adequate moisture, and promoting the proliferation of epithelial cells. The BC/GO-Ag hybrid materials exhibited excellent mechanical flexibility and low cytotoxicity to fibroblast cells, making excellent wound dressings able to control bacterial infectious processes and promote the fast healing of dermal lesions.


Subject(s)
Anti-Bacterial Agents , Biocompatible Materials , Cellulose , Escherichia coli , Graphite , Materials Testing , Metal Nanoparticles , Microbial Sensitivity Tests , Silver , Staphylococcus aureus , Wound Healing , Graphite/chemistry , Graphite/pharmacology , Silver/chemistry , Silver/pharmacology , Wound Healing/drug effects , Cellulose/chemistry , Cellulose/pharmacology , Metal Nanoparticles/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Staphylococcus aureus/drug effects , Escherichia coli/drug effects , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Particle Size , Pseudomonas aeruginosa/drug effects , Gluconacetobacter xylinus/chemistry , Humans , Mice , Bandages , Animals
16.
Molecules ; 29(14)2024 Jul 10.
Article in English | MEDLINE | ID: mdl-39064841

ABSTRACT

Bone tissue engineering is a promising alternative to repair wounds caused by cellular or physical accidents that humans face daily. In this sense, the search for new graphene oxide (GO) nanofillers related to their degree of oxidation is born as an alternative bioactive component in forming new scaffolds. In the present study, three different GOs were synthesized with varying degrees of oxidation and studied chemically and tissue-wise. The oxidation degree was determined through infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron (XPS), and Raman spectroscopy (RS). The morphology of the samples was analyzed using scanning electron microscopy (SEM). The oxygen content was deeply described using the deconvolution of RS and XPS techniques. The latter represents the oxidation degree for each of the samples and the formation of new bonds promoted by the graphitization of the material. In the RS, two characteristic bands were observed according to the degree of oxidation and the degree of graphitization of the material represented in bands D and G with different relative intensities, suggesting that the samples have different crystallite sizes. This size was described using the Tuinstra-Koenig model, ranging between 18.7 and 25.1 nm. Finally, the bone neoformation observed in the cranial defects of critical size indicates that the F1 and F2 samples, besides being compatible and resorbable, acted as a bridge for bone healing through regeneration. This promoted healing by restoring bone and tissue structure without triggering a strong immune response.


Subject(s)
Bone Regeneration , Graphite , Tissue Engineering , Tissue Scaffolds , Graphite/chemistry , Bone Regeneration/drug effects , Tissue Engineering/methods , Animals , Tissue Scaffolds/chemistry , Nanostructures/chemistry , Bone and Bones/drug effects , Spectrum Analysis, Raman , Oxidation-Reduction , X-Ray Diffraction , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Rats , Spectroscopy, Fourier Transform Infrared
17.
Sensors (Basel) ; 24(14)2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39066066

ABSTRACT

This work explores the transformative role of graphene in enhancing the performance of surface plasmon resonance (SPR)-based biosensors. The motivation for this review stems from the growing interest in the unique properties of graphene, such as high surface area, excellent electrical conductivity, and versatile functionalization capabilities, which offer significant potential to improve the sensitivity, specificity, and stability of SPR biosensors. This review systematically analyzes studies published between 2010 and 2023, covering key metrics of biosensor performance. The findings reveal that the integration of graphene consistently enhances sensitivity. Specificity, although less frequently reported numerically, showed promising results, with high specificity achieved at sub-nanomolar concentrations. Stability enhancements are also significant, attributed to the protective properties of graphene and improved biomolecule adsorption. Future research should focus on mechanistic insights, optimization of integration techniques, practical application testing, scalable fabrication methods, and comprehensive comparative studies. Our findings provide a foundation for future research, aiming to further optimize and harness the unique physical properties of graphene to meet the demands of sensitive, specific, stable, and rapid biosensing in various practical applications.


Subject(s)
Biosensing Techniques , Graphite , Surface Plasmon Resonance , Surface Plasmon Resonance/methods , Graphite/chemistry , Biosensing Techniques/methods , Humans
18.
Environ Sci Pollut Res Int ; 31(31): 44374-44384, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38949732

ABSTRACT

The presence of phenazopyridine in water is an environmental problem that can cause damage to human health and the environment. However, few studies have reported the adsorption of this emerging contaminant from aqueous matrices. Furthermore, existing research explored only conventional modeling to describe the adsorption phenomenon without understanding the behavior at the molecular level. Herein, the statistical physical modeling of phenazopyridine adsorption into graphene oxide is reported. Steric, energetic, and thermodynamic interpretations were used to describe the phenomenon that controls drug adsorption. The equilibrium data were fitted by mono, double, and multi-layer models, considering factors such as the numbers of phenazopyridine molecules by adsorption sites, density of receptor sites, and half saturation concentration. Furthermore, the statistical physical approach also calculated the thermodynamic parameters (free enthalpy, internal energy, Gibbs free energy, and entropy). The maximum adsorption capacity at the equilibrium was reached at 298 K (510.94 mg g-1). The results showed the physical meaning of adsorption, indicating that the adsorption occurs in multiple layers. The temperature affected the density of receptor sites and half saturation concentration. At the same time, the adsorbed species assumes different positions on the adsorbent surface as a function of the increase in the temperature. Meanwhile, the thermodynamic functions revealed increased entropy with the temperature and the equilibrium concentration.


Subject(s)
Nanostructures , Thermodynamics , Adsorption , Nanostructures/chemistry , Analgesics/chemistry , Graphite/chemistry , Water Pollutants, Chemical/chemistry , Carbon/chemistry
19.
Nanotechnology ; 35(42)2024 Aug 02.
Article in English | MEDLINE | ID: mdl-39059417

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), etiological agent for the coronavirus disease 2019 (COVID-19), has resulted in over 775 million global infections. Early diagnosis remains pivotal for effective epidemiological surveillance despite the availability of vaccines. Antigen-based assays are advantageous for early COVID-19 detection due to their simplicity, cost-effectiveness, and suitability for point-of-care testing (PoCT). This study introduces a graphene field-effect transistor-based biosensor designed for high sensitivity and rapid response to the SARS-CoV-2 spike protein. By functionalizing graphene with monoclonal antibodies and applying short-duration gate voltage pulses, we achieve selective detection of the viral spike protein in human serum within 100 µs and at concentrations as low as 1 fg ml-1, equivalent to 8 antigen molecules perµl of blood. Furthermore, the biosensor estimates spike protein concentrations in serum from COVID-19 patients. Our platform demonstrates potential for next-generation PoCT antigen assays, promising fast and sensitive diagnostics for COVID-19 and other infectious diseases.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Transistors, Electronic , Spike Glycoprotein, Coronavirus/analysis , Spike Glycoprotein, Coronavirus/immunology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Graphite/chemistry , Humans , SARS-CoV-2/isolation & purification , SARS-CoV-2/immunology , COVID-19/diagnosis , COVID-19/blood , COVID-19/virology , Sensitivity and Specificity , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/chemistry
20.
Chemosphere ; 363: 142738, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39004147

ABSTRACT

Herein, graphene oxide was used as the highly efficient phenazopyridine adsorbent from aqueous medium, synthetic, and human urine. The nanoadsorbent was characterized by different instrumental techniques. The adsorption capacity (1253.17 mg g-1) was reached at pH 5.0, using an adsorbent dosage of 0.125 g L-1 at 298 K. The Sips and Langmuir described the equilibrium data well. At the same time, the pseudo-second order was more suitable for fitting the kinetic data. Thermodynamic parameters revealed the exothermic nature of adsorption with an increase in randomness at the solid-liquid interface. The magnitude of the enthalpy variation value indicates that the process involves the physisorption phenomenon. At the same time, ab initio molecular dynamics data corroborated with the thermodynamic results, indicating that adsorbent and adsorbate establish hydrogen bonds through the amine groups (adsorbate) and hydroxyl groups on the adsorbent surface (weak interactions). Electrostatic interactions are also involved. Additionally, the adsorption assays conducted in simulated medium and human urine showed the excellent performance of adsorbent material to remove the drug in real concentrations excreted by the kidneys (removal values higher than 60%).


Subject(s)
Graphite , Phenazopyridine , Thermodynamics , Water Pollutants, Chemical , Graphite/chemistry , Adsorption , Phenazopyridine/chemistry , Phenazopyridine/urine , Humans , Water Pollutants, Chemical/chemistry , Kinetics , Density Functional Theory , Water Purification/methods , Urine/chemistry
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