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1.
Talanta ; 243: 123356, 2022 Jun 01.
Article in English | MEDLINE | ID: covidwho-1778464

ABSTRACT

The increasing mutation frequency of the SARS-CoV-2 virus and the emergence of successive variants have made correct diagnosis hard to perform. Developing efficient and accurate methods to diagnose infected patients is crucial to effectively mitigate the pandemic. Here, we developed an electrochemical immunosensor based on SARS-CoV-2 antibody cocktail-conjugated magnetic nanoparticles for the sensitive and accurate detection of the SARS-CoV-2 virus and its variants in nasopharyngeal swabs. The application of the antibody cocktail was compared with commercially available anti-SARS-CoV-2 S1 (anti-S1) and anti-S2 monoclonal antibodies. After optimization and calibration, the limit of detection (LOD) determination demonstrated a LOD = 0.53-0.75 ng/mL for the antibody cocktail-based sensor compared with 0.93 ng/mL and 0.99 ng/mL for the platforms using anti-S1 and anti-S2, respectively. The platforms were tested with human nasopharyngeal swab samples pre-diagnosed with RT-PCR (10 negatives and 40 positive samples). The positive samples include the original, alpha, beta, and delta variants (n = 10, for each). The polyclonal antibody cocktail performed better than commercial anti-S1 and anti-S2 antibodies for all samples reaching 100% overall sensitivity, specificity, and accuracy. It also showed a wide range of variants detection compared to monoclonal antibody-based platforms. The present work proposes a versatile electrochemical biosensor for the indiscriminate detection of the different variants of SARS-CoV-2 using a polyclonal antibody cocktail. Such diagnostic tools allowing the detection of variants can be of great efficiency and economic value in the fight against the ever-changing SARS-CoV-2 virus.


Subject(s)
Biosensing Techniques , COVID-19 , Magnetite Nanoparticles , COVID-19/diagnosis , Humans , Immunoassay , SARS-CoV-2/genetics
2.
IET Nanobiotechnol ; 16(3): 85-91, 2022 May.
Article in English | MEDLINE | ID: covidwho-1758388

ABSTRACT

Mesoporous magnetic nanoparticles of haematite were synthesised using plant extracts according to bioethics principles. The structural, physical and chemical properties of mesoporous Fe2 O3 nanoparticles synthesised with the green chemistry approach were evaluated by XRD, SEM, EDAX, BET, VSM and HRTEM analysis. Then, their toxicity against normal HUVECs and MCF7 cancer cells was evaluated by MTT assay for 48 h. These biogenic mesoporous magnetic nanoparticles have over 71% of doxorubicin loading efficiency, resulting in a 50% reduction of cancer cells at a 0.5 µg.ml-1 concentration. Therefore, it is suggested that mesoporous magnetic nanoparticles be used as a multifunctional agent in medicine (therapeutic-diagnostic). The produced mesoporous magnetic nanoparticles with its inherent structural properties such as polygonal structure (increasing surface area to particle volume) and porosity with large pore volume became a suitable substrate for loading the anti-cancer drug doxorubicin.


Subject(s)
Nanoparticles , Silicon Dioxide , Doxorubicin/chemistry , Doxorubicin/pharmacology , Drug Carriers/chemistry , Drug Delivery Systems/methods , Drug Liberation , Humans , Nanoparticles/chemistry , Porosity , Silicon Dioxide/chemistry
3.
Non-conventional in English | National Technical Information Service, Grey literature | ID: grc-753648

ABSTRACT

Traumatic brain injury (TBI) currently afflicts 357,000 enlisted military men and women in the US Armed Services. For the most common form of TBI, Mild Traumatic Brain Injury (mTBI) most patients recover within a year following the incident, but 10-20 of mild cases result in a long-term disability including seizures and emotional and behavioral issues. Although much has been learned about molecular changes in the brain following injury, access to these biomarkers following mTBI is lacking. The accurate diagnosis and precise individual clinical management of traumatic brain injury (TBI) is limited by the lack of accessible molecular biomarkers that are informative regarding the unique mixture of injury mechanisms in each TBI patient.

4.
Applied Sciences ; 11(21):9786, 2021.
Article in English | ProQuest Central | ID: covidwho-1674438

ABSTRACT

Frequent tests for CD4+ T cell counting are important for the treatment of patients with immune deficiency;however, the routinely used fluorescence-activated cell-sorting (FACS) gold standard is costly and the equipment is only available in central hospitals. In this study, we developed an alternative simple approach (shortly named as the MACS-Countess system) for CD4+ T cell counting by coupling magnetic activated cell sorting (MACS) to separate CD4+ T cells from blood, followed by counting the separated cells using CountessTM, an automated cell-counting system. Using the cell counting protocol, 25 µL anti-CD4 conjugated magnetic nanoparticles (NP-CD4, BD Bioscience) were optimized for separating CD4+ T cells from 50 µL of blood in PBS using a DynamagTM-2 magnet, followed by the introduction of 10 µL separated cells into a CountessTM chamber slide for automated counting of CD4+ T cells. To evaluate the reliability of the developed method, 48 blood samples with CD4+ T cell concentrations ranging from 105 to 980 cells/µL were analyzed using both MACS-Countess and FACS. Compared with FACS, MACS-Countess had a mean bias of 3.5% with a limit of agreement (LoA) ranging from −36.4% to 43.3%, which is close to the reliability of the commercial product, PIMA analyzer (Alere), reported previously (mean bias 0.2%;LoA ranging from −42% to 42%, FACS as reference). Further, the MACS-Countess system requires very simple instruments, including only a magnet and an automated cell counter, which are affordable for almost every lab located in a limited resource region.

5.
Nanomaterials (Basel) ; 12(2)2022 Jan 08.
Article in English | MEDLINE | ID: covidwho-1637239

ABSTRACT

Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia. One of the critical characteristics of nanoparticles to adjust to the biomedical needs of each application is their polymeric coating. Fatty acid coatings are known to contribute to colloidal stability and good surface crystalline quality. While monolayer coatings make the particles hydrophobic, a fatty acid double-layer renders them hydrophilic, and therefore suitable for use in body fluids. In addition, they provide the particles with functional chemical groups that allow their bioconjugation. This work analyzes three types of self-assembled bilayer fatty acid coatings of superparamagnetic iron oxide nanoparticles: oleic, lauric, and myristic acids. We characterize the particles magnetically and structurally and study their potential for resonance imaging, magnetic hyperthermia, and labeling for biosensing in lateral flow immunoassays. We found that the myristic acid sample reported a large r2 relaxivity, superior to existing iron-based commercial agents. For magnetic hyperthermia, a significant specific absorption rate value was obtained for the oleic sample. Finally, the lauric acid sample showed promising results for nanolabeling.

6.
Talanta ; 241: 123243, 2022 May 01.
Article in English | MEDLINE | ID: covidwho-1633997

ABSTRACT

Viral diseases are the primary source of death, making a worldwide influence on healthcare, social, and economic development. Thus, diagnosis is the vital approach to the main aim of virus control and elimination. On the other hand, the prompt advancement of nanotechnology in the field of medicine possesses the probability of being beneficial to diagnose infections normally in labs as well as specifically. Nanoparticles are efficiently in use to make novel strategies because of permitting analysis at cellular in addition to the molecular scale. Henceforth, they assist towards pronounced progress concerning molecular analysis at the nanoscale. In recent times, magnetic nanoparticles conjugated through covalent bonds to bioanalytes for instance peptides, antibodies, nucleic acids, plus proteins are established like nanoprobes aimed at molecular recognition. These modified magnetic nanoparticles could offer a simple fast approach for extraction, purification, enrichment/concentration, besides viruses' recognition precisely also specifically. In consideration of the above, herein insight and outlook into the limitations of conventional methods and numerous roles played by magnetic nanoparticles to extract, purify, concentrate, and additionally in developing a diagnostic regime for viral outbreaks to combat viruses especially the ongoing novel coronavirus (COVID-19).


Subject(s)
COVID-19 , Viruses , Humans , Magnetic Phenomena , Magnetics , SARS-CoV-2 , Viruses/genetics
7.
Anal Biochem ; 635: 114445, 2021 12 15.
Article in English | MEDLINE | ID: covidwho-1565506

ABSTRACT

The outbreak of COVID-19 makes epidemic prevention and control become a growing global concern. Nucleic acid amplification testing (NAAT) can realize early and rapid detection of targets, thus it is considered as an ideal approach for detecting pathogens of severe acute infectious diseases. Rapid acquisition of high-quality target nucleic acid is the prerequisite to ensure the efficiency and accuracy of NAAT. Herein, we proposed a simple system in which magnetic nanoparticles (MNPs) based nucleic acid extraction was carried out in a plastic Pasteur pipette. Different from traditional approaches, this proposed system could be finished in 15 min without the supports of any electrical instruments. Furthermore, this system was superior to traditional MNPs based extraction methods in the aspects of rapid extraction and enhancing the sensitivity of a NAAT method, accelerated denaturation bubbles mediated strand exchange amplification (ASEA), to the pathogens from various artificial samples. Finally, this Pasteur pipette system was utilized for pathogen detection in actual samples of throat swabs, cervical swabs and gastric mucosa, the diagnosis results of which were identical with that provided by hospital. This rapid, easy-performing and efficiency extraction method ensures the applications of the NAAT in pathogen detection in regions with restricted resources.


Subject(s)
Infections/diagnosis , Magnetite Nanoparticles , Nucleic Acid Amplification Techniques/methods , Nucleic Acids/isolation & purification , COVID-19/diagnosis , Helicobacter Infections/diagnosis , Helicobacter pylori/isolation & purification , Human papillomavirus 16/isolation & purification , Humans , Papillomavirus Infections/diagnosis , Pneumonia, Mycoplasma/diagnosis , SARS-CoV-2/isolation & purification
8.
Appl Phys A Mater Sci Process ; 127(12): 960, 2021.
Article in English | MEDLINE | ID: covidwho-1536297

ABSTRACT

Genetic variants of the COVID-19 causative virus have been arising and circulating globally. In many countries, especially in developing ones with a huge population, vaccination has become one of the major challenges. SARS-CoV-2 variants' fast transmission rate has an upsurge in the COVID cases, leading to more stress on health systems. In the current COVID-19 scenario, there is the requirement of more adequate diagnostic approaches to check the COVID-19 spread. Out of many diagnostic approaches, a magnetic nanoparticle-based reverse transcription polymerase chain reaction could be nontrivial. The use of magnetic nanoparticles is to separate nucleic acid of SARS-CoV-2 from the patient samples and apply for SARS-CoV-2 detection in an easy and more effective way. Herein, the magnetic nanoparticles are synthesized using the solgel autocombustion methods and then successfully coated with biopolymer (chitosan) using ultrasonication. Chitosan-coated nanoparticles are successfully integrated into the graphene oxide sheets to introduce carboxyl groups. Crystallite size calculation, morphological and magnetic studies of synthesized magnetic nanoparticles, and multifunctional magnetic nanoparticles are done using XRD, SEM, TEM, and VSM, respectively. Besides, the potentiality of the fabricated nanocomposites in RNA extraction protocol is also discussed with schematic representation.

9.
Inorg Chem Commun ; 134: 108995, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1458846

ABSTRACT

In recent decades, the use of engineered nanoparticles has been increasing in various sectors, including biomedicine, diagnosis, water treatment, and environmental remediation leading to significant public concerns. Among these nanoparticles, magnetic nanoparticles (MNPs) have gained many attentions in medicine, pharmacology, drug delivery system, molecular imaging, and bio-sensing due to their various properties. In addition, various studies have reviewed MNPs main applications in the biomedical engineering area with intense progress and recent achievements. Nanoparticles, especially the magnetic nanoparticles, have recently been confirmed with excellent antiviral activity against different viruses, including SARS-CoV-2(Covid-19) and their recent development against Covid-19 also has also been discussed. This review aims to highlight the recent development of the magnetic nanoparticles and their biomedical applications such as diagnosis of diseases, molecular imaging, hyperthermia, bio-sensing, gene therapy, drug delivery and the diagnosis of Covid-19.

10.
ACS Appl Bio Mater ; 4(8): 5839-5870, 2021 08 16.
Article in English | MEDLINE | ID: covidwho-1345532

ABSTRACT

Precisely engineered magnetic nanoparticles (MNPs) have been widely explored for applications including theragnostic platforms, drug delivery systems, biomaterial/device coatings, tissue engineering scaffolds, performance-enhanced therapeutic alternatives, and even in SARS-CoV-2 detection strips. Such popularity is due to their unique, challenging, and tailorable physicochemical/magnetic properties. Given the wide biomedical-related potential applications of MNPs, significant achievements have been reached and published (exponentially) in the last five years, both in synthesis and application tailoring. Within this review, and in addition to essential works in this field, we have focused on the latest representative reports regarding the biomedical use of MNPs including characteristics related to their oriented synthesis, tailored geometry, and designed multibiofunctionality. Further, actual trends, needs, and limitations of magnetic-based nanostructures for biomedical applications will also be discussed.


Subject(s)
Magnetics , Magnetite Nanoparticles/chemistry , Animals , COVID-19/diagnosis , COVID-19/virology , Drug Carriers/chemistry , History, 17th Century , Humans , Magnetite Nanoparticles/history , SARS-CoV-2/isolation & purification , Theranostic Nanomedicine , Tissue Engineering
11.
Biosens Bioelectron ; 192: 113536, 2021 Nov 15.
Article in English | MEDLINE | ID: covidwho-1330665

ABSTRACT

The ongoing COVID-19 pandemic stresses the need for widely available diagnostic tests for the presence of SARS-CoV-2 in individuals. Due to the limited availability of vaccines, diagnostic assays which are cheap, easy-to-use at the point-of-need, reliable and fast, are currently the only way to control the pandemic situation. Here we present a diagnostic assay for the detection of pathogen-specific nucleic acids based on changes of the magnetic response of magnetic nanoparticles: The target-mediated hybridization of modified nanoparticles leads to an increase in the hydrodynamic radius. This resulting change in the magnetic behaviour in an ac magnetic field can be measured via magnetic particle spectroscopy (MPS), providing a viable tool for the accurate detection of target nucleic acids. In this work we show that single stranded DNA can be detected in a concentration-dependent manner by these means. In addition to detecting synthetic DNA with an arbitrary sequence in a concentration down to 500 pM, we show that RNA and SARS-CoV-2-specific DNA as well as saliva as a sample medium can be used for an accurate assay. These proof-of-principle experiments show the potential of MPS based assays for the reliable and fast diagnostics of pathogens like SARS-CoV-2 in a point-of-need fashion without the need of complex sample preparation.


Subject(s)
Biosensing Techniques , COVID-19 , Nucleic Acids , Humans , Magnetic Phenomena , Pandemics , RNA, Viral , SARS-CoV-2 , Sensitivity and Specificity , Spectrum Analysis
12.
Sci Total Environ ; 784: 147174, 2021 Aug 25.
Article in English | MEDLINE | ID: covidwho-1189000

ABSTRACT

Psychological disorders due to the COVID-19 pandemic have increased the consumption of psychiatric pharmaceuticals on a global scale in last year. These compounds reach wastewater treatment plants (WWTP) through sewerage system and are not sufficiently removed by using conventional treatment process. Psychiatric drugs released with WWTP effluent may cause possible risks to the receiving aquatic environment. Also, two antidepressants have been included in the "watch list" in 2020. Therefore, simple and relatively cost effective removal of psychiatric drugs from wastewaters becomes important. Magnetite red mud nanoparticles (RM-NPs) synthesized was applied for the removal of psychiatric drugs (fluoxetine, paroxetine, carbamazepine, diazepam, and lorazepam) in WWTP effluent first time in this study. The adsorption of carbamazepine as a model compound was fitted well with pseudo-second-order kinetic model. The Freundlich isotherm model better represented the sorption data than the Langmuir model. High adsorption capacity (90.5 mg/g) was reached at 30 min contact time at pH 6.5-7.0 at 25 °C. The adsorption rate was described by the pseudo second order model and its rate control mechanism was controlled by film diffusion. The magnetite RM-NPs were efficiently used for the removal of carbamazepine from real WWTP effluents. The adsorption capacity and the magnetic separability of the regenerated magnetite RM-NPs were unaffected five cycles. Due to its simple application, low cost and high adsorption capacity, magnetite RM-NPs can be recommended as a better adsorbent comparing to commercial adsorbents to remove psychiatric drugs from WWTP effluents.


Subject(s)
COVID-19 , Magnetite Nanoparticles , Pharmaceutical Preparations , Water Pollutants, Chemical , Water Purification , Adsorption , Ferrosoferric Oxide , Humans , Hydrogen-Ion Concentration , Kinetics , Pandemics , SARS-CoV-2 , Water Pollutants, Chemical/analysis
13.
Pharmaceuticals (Basel) ; 14(4)2021 Apr 06.
Article in English | MEDLINE | ID: covidwho-1178382

ABSTRACT

Human induced pluripotent stem cells (hiPSCs) and hiPSCs-derived cells have the potential to revolutionize regenerative and precision medicine. Genetically reprograming somatic cells to generate hiPSCs and genetic modification of hiPSCs are considered the key procedures for the study and application of hiPSCs. However, there are significant technical challenges for transgene delivery into somatic cells and hiPSCs since these cells are known to be difficult to transfect. The existing methods, such as viral transduction and chemical transfection, may introduce significant alternations to hiPSC culture which affect the potency, purity, consistency, safety, and functional capacity of hiPSCs. Therefore, generation and genetic modification of hiPSCs through non-viral approaches are necessary and desirable. Nanotechnology has revolutionized fields from astrophysics to biology over the past two decades. Increasingly, nanoparticles have been used in biomedicine as powerful tools for transgene and drug delivery, imaging, diagnostics, and therapeutics. The most successful example is the recent development of SARS-CoV-2 vaccines at warp speed to combat the 2019 coronavirus disease (COVID-19), which brought nanoparticles to the center stage of biomedicine and demonstrated the efficient nanoparticle-mediated transgene delivery into human body. Nanoparticles have the potential to facilitate the transgene delivery into the hiPSCs and offer a simple and robust approach. Nanoparticle-mediated transgene delivery has significant advantages over other methods, such as high efficiency, low cytotoxicity, biodegradability, low cost, directional and distal controllability, efficient in vivo applications, and lack of immune responses. Our recent study using magnetic nanoparticles for transfection of hiPSCs provided an example of the successful applications, supporting the potential roles of nanoparticles in hiPSC biology. This review discusses the principle, applications, and significance of nanoparticles in the transgene delivery to hiPSCs and their successful application in the development of COVID-19 vaccines.

14.
Glob Chall ; : 2000068, 2021 Feb 22.
Article in English | MEDLINE | ID: covidwho-1160536

ABSTRACT

Molecular diagnosis and surveillance of pathogens such as SARS-CoV-2 depend on nucleic acid isolation. Pandemics at the scale of COVID-19 can cause a global shortage of proprietary commercial reagents and BSL-2 laboratories to safely perform testing. Therefore, alternative solutions are urgently needed to address these challenges. An open-source method, magnetic-nanoparticle-aided viral RNA isolation from contagious samples (MAVRICS), built upon readily available reagents, and easily assembled in any basically equipped laboratory, is thus developed. The performance of MAVRICS is evaluated using validated pathogen detection assays and real-world and contrived samples. Unlike conventional methods, MAVRICS works directly in samples inactivated in phenol-chloroform (e.g., TRIzol), thus allowing infectious samples to be handled safely without biocontainment facilities. MAVRICS allows wastewater biomass immobilized on membranes to be directly inactivated and lysed in TRIzol followed by RNA extraction by magnetic nanoparticles, thereby greatly reducing biohazard risk and simplifying processing procedures. Using 39 COVID-19 patient samples and two wastewater samples, it is shown that MAVRICS rivals commercial kits in detection of SARS-CoV-2, influenza viruses, and respiratory syncytial virus. Therefore, MAVRICS is safe, fast, and scalable. It is field-deployable with minimal equipment requirements and could become an enabling technology for widespread testing and wastewater monitoring of diverse pathogens.

15.
Sens Actuators B Chem ; 337: 129786, 2021 Jun 15.
Article in English | MEDLINE | ID: covidwho-1146819

ABSTRACT

The rapid and sensitive diagnosis of the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the crucial issues at the outbreak of the ongoing global pandemic that has no valid cure. Here, we propose a SARS-CoV-2 antibody conjugated magnetic graphene quantum dots (GQDs)-based magnetic relaxation switch (MRSw) that specifically recognizes the SARS-CoV-2. The probe of MRSw can be directly mixed with the test sample in a fully sealed vial without sample pretreatment, which largely reduces the testers' risk of infection during the operation. The closed-tube one-step strategy to detect SARS-CoV-2 is developed with home-made ultra-low field nuclear magnetic resonance (ULF NMR) relaxometry working at 118 µT. The magnetic GQDs-based probe shows ultra-high sensitivity in the detection of SARS-CoV-2 due to its high magnetic relaxivity, and the limit of detection is optimized to 248 Particles mL‒1. Meanwhile, the detection time in ULF NMR system is only 2 min, which can significantly improve the efficiency of detection. In short, the magnetic GQDs-based MRSw coupled with ULF NMR can realize a rapid, safe, and sensitive detection of SARS-CoV-2.

16.
ACS Sens ; 6(3): 976-984, 2021 03 26.
Article in English | MEDLINE | ID: covidwho-1047925

ABSTRACT

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global medical systems and economies and rules our daily living life. Controlling the outbreak of SARS-CoV-2 has become one of the most important and urgent strategies throughout the whole world. As of October 2020, there have not yet been any medicines or therapies to be effective against SARS-CoV-2. Thus, rapid and sensitive diagnostics is the most important measures to control the outbreak of SARS-CoV-2. Homogeneous biosensing based on magnetic nanoparticles (MNPs) is one of the most promising approaches for rapid and highly sensitive detection of biomolecules. This paper proposes an approach for rapid and sensitive detection of SARS-CoV-2 with functionalized MNPs via the measurement of their magnetic response in an ac magnetic field. For proof of concept, mimic SARS-CoV-2 consisting of spike proteins and polystyrene beads are used for experiments. Experimental results demonstrate that the proposed approach allows the rapid detection of mimic SARS-CoV-2 with a limit of detection of 0.084 nM (5.9 fmole). The proposed approach has great potential for designing a low-cost and point-of-care device for rapid and sensitive diagnostics of SARS-CoV-2.


Subject(s)
Antibodies, Monoclonal/chemistry , Magnetite Nanoparticles/chemistry , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Antibodies, Monoclonal/immunology , Biosensing Techniques , Magnetic Phenomena , Polystyrenes/chemistry , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology
17.
Nanomaterials (Basel) ; 10(7)2020 Jun 29.
Article in English | MEDLINE | ID: covidwho-625962

ABSTRACT

The eradication of viral infections is an ongoing challenge in the medical field, as currently evidenced with the newly emerged Coronavirus disease 2019 (COVID-19) associated with severe respiratory distress. As treatments are often not available, early detection of an eventual infection and its level becomes of outmost importance. Nanomaterials and nanotechnological approaches are increasingly used in the field of viral sensing to address issues related to signal-to-noise ratio, limiting the sensitivity of the sensor. Superparamagnetic nanoparticles (MPs) present one of the most exciting prospects for magnetic bead-based viral aggregation assays and their integration into different biosensing strategies as they can be easily separated from a complex matrix containing the virus through the application of an external magnetic field. Despite the enormous potential of MPs as capture/pre-concentrating elements, they are not ideal with regard of being active elements in sensing applications as they are not the sensor element itself. Even though engineering of magneto-plasmonic nanostructures as promising hybrid materials directly applicable for sensing due to their plasmonic properties are often used in sensing, to our surprise, the literature of magneto-plasmonic nanostructures for viral sensing is limited to some examples. Considering the wide interest this topic is evoking at present, the different approaches will be discussed in more detail and put into wider perspectives for sensing of viral disease markers.

18.
Mater Today Proc ; 37: 1469-1474, 2021.
Article in English | MEDLINE | ID: covidwho-695430

ABSTRACT

Quinolines are an interesting class of moieties with various medicinal chemistry uses. The most prominent is their ability to be used as the last line of therapy for bacterial and viral infections including recent COVID-19. The synthesis of quinoline is through a cyclization reaction and overall reaction yields are about 20%. The bulky ring and the associated crowding of functional groups limit the catalyst options. In this publication, the use of Fe3O4@SiO2 for enhancing yield improvements, especially for heterocyclics is reported. The use of the 40 nm sized silica functionalized magnetite nanoparticles seems to help in both condensation and cyclization steps of representative 2-methyl-6-nitroquinoline. Reaction time reduction due to surface enabled catalysis of nanoparticles is 110 min to 80 min. The reaction yield has doubled due to the presence of catalyst and the mechanism suggests this drastic result is due to stabilization of unstable intermediate on the acidic surface of the silica coating. This near homogeneous catalysis of 40 nm sized, silica functionalized, magnetite nanoparticles have far reaching applications in bulk drug industry for drugs like chloroquine & hydroxychloroquine, the two essential drugs for prophylactic use for COVID-1.

19.
Appl Surf Sci ; 524: 146602, 2020 Sep 15.
Article in English | MEDLINE | ID: covidwho-197730

ABSTRACT

Phototherapies, including photodynamic therapy (PDT), have been widely used in the treatment of various diseases, especially for cancer. However, there is still a lack of effective, safe photosensitizers that would be well tolerated by patients. The combination of several methods (like phototherapy and hyperthermia) constitutes a modern therapeutic approach, which demands new materials based on components that are non-toxic without irradiation. Therefore, this study presents the synthesis and properties of novel, advanced nanomaterials in which the advantage features of the magnetic nanoparticles and photoactive compounds were combined. The primary purpose of this work was the synthesis of magnetic nanoparticles coated with biocompatible and antitumor polysaccharide - levan, previously unknown from scientific literature, and the deposition of potent photosensitizer - zinc(II) phthalocyanine on their surface. In order to better characterize the nature of the coating covering the magnetic core, the atomic force microscope analysis, a contact angle measurement, and the mechanical properties of pure levan and its blend with zinc(II) phthalocyanine films were investigated. This magnetic nanomaterial revealed the ability to generate singlet oxygen upon exposure to light. Finally, preliminary toxicity of obtained nanoparticles was tested using the Microtox® test - with and without irradiation.

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