Detection of tetanus toxoid with iron magnetic nanobioprobe

Diagnosis of diseases with low facilities, speed, accuracy and sensitivity is an important matter in treatment. Bioprobes based on iron oxide nanoparticles are a good candidate for early detection of deadly and infectious diseases such as tetanus due to their high reactivity, biocompatibility, low production cost and sample separation under a magnetic field. In this study, silane groups were coated on surface of iron oxide nanoparticles using tetraethoxysilane (TEOS) hydrolysis. Also, NH2groups were generated on the surface of silanized nanoparticles using 3-aminopropyl triethoxy silane (APTES). Antibody was immobilized on the surface of silanized nanoparticles using TCT trichlorothriazine as activator. Silanization and stabilized antibody were investigated by using of FT-IR, EDX, VSM, SRB technique. UV/vis spectroscopy, fluorescence, agglutination test and ELISA were used for biosensor performance and specificity. The results of FT-IR spectroscopy showed that Si-O-Si and Si-O-Fe bonds and TCT chlorine and amine groups of tetanus anti-toxoid antibodies were formed on the surface of iron oxide nanoparticles. The presence of Si, N and C elements in EDX analysis confirms the silanization of iron oxide nanoparticles. VSM results showed that the amount of magnetic nanoparticles after conjugation is sufficient for biological applications. Antibody stabilization on nanoparticles increased the adsorption intensity in the uv/vis spectrometer. The fluorescence intensity of nano bioprobe increased in the presence of 10 ng ml-1. Nanobio probes were observed as agglomerates in the presence of tetanus toxoid antigen. The presence of tetanus antigen caused the formation of antigen-nanobioprobe antigen complex. Identification of this complex by HRP-bound antibody confirmed the specificity of nanobioprobe. Tetanus magnetic nanobioprobe with a diagnostic limit of 10 ng ml-1of tetanus antigen in a short time can be a good tool in LOC devices and microfluidic chips.

Optimization of Alpha-Amylase Production by a Local Bacillus paramycoides Isolate and Immobilization on Chitosan-Loaded Barium Ferrite Nanoparticles

We set out to isolate alpha-amylase producers from soil samples, optimize the production, and immobilize the enzyme on chitosan-loaded barium ferrite nanoparticles (CLBFNPs). Alpha-amylase producers were isolated on starch agar plates and confirmed by dinitrosalicylic acid assay. The potent isolate was identified by phenotypic methods, 16S-rRNA sequencing, and phylogenetic mapping. Sequential optimization of α-amylase production involved the use of Plackett–Burman (P–BD) and central composite designs (CCD), in addition to exposing the culture to different doses of gamma irradiation. Alpha-amylase was immobilized on CLBFNPs, and the nanocomposite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy, with energy-dispersive analysis of X-ray analysis. Forty-five α-amylase producers were isolated from 100 soil samples. The highest activity (177.12 ± 6.12 U/mg) was detected in the MS009 isolate, which was identified as Bacillus paramycoides. The activity increased to 222.3 ± 5.07 U/mg when using the optimal culture conditions identified by P–BD and CCD, and to 319.45 ± 4.91 U/mg after exposing the culture to 6 kGy. Immobilization of α-amylase on CLBFNPs resulted in higher activity (246.85 ± 6.76 U/mg) compared to free α-amylase (222.254 ± 4.89 U/mg), in addition to retaining activity for up to five cycles of usage. Gamma irradiation improved α-amylase production, while immobilization on CLBFNPs enhanced activity, facilitated enzyme recovery, and enabled its repetitive use.

Advances in the Synthesis and Application of Magnetic Ferrite Nanoparticles for Cancer Therapy

Cancer is among the leading causes of mortality globally, with nearly 10 million deaths in 2020. The emergence of nanotechnology has revolutionised treatment strategies in medicine, with rigorous research focusing on designing multi-functional nanoparticles (NPs) that are biocompatible, non-toxic, and target-specific. Iron-oxide-based NPs have been successfully employed in theranostics as imaging agents and drug delivery vehicles for anti-cancer treatment. Substituted iron-oxides (MFe2O4) have emerged as potential nanocarriers due to their unique and attractive properties such as size and magnetic tunability, ease of synthesis, and manipulatable properties. Current research explores their potential use in hyperthermia and as drug delivery vehicles for cancer therapy. Significantly, there are considerations in applying iron-oxide-based NPs for enhanced biocompatibility, biodegradability, colloidal stability, lowered toxicity, and more efficient and targeted delivery. This review covers iron-oxide-based NPs in cancer therapy, focusing on recent research advances in the use of ferrites. Methods for the synthesis of cubic spinel ferrites and the requirements for their considerations as potential nanocarriers in cancer therapy are discussed. The review highlights surface modifications, where functionalisation with specific biomolecules can deliver better efficiency. Finally, the challenges and solutions for the use of ferrites in cancer therapy are summarised.

Portable quantification of silver ion by using personal glucose meter (PGM) and magnetite cross-linked invertase aggregates (MCLIA)

Heavy metal detection is critical due to its harmful effects on human health and the ecosystem. Enzyme-based platforms attract attention for heavy metal detection such as silver, a toxic metal, due to being small, portable, and requiring only essential equipment compared with the basic analytical methods. In this study, magnetic cross-linked invertase aggregates (MCLIA) were developed for the first time as an enzyme-based signaling platform to detect Ag⁺ using a personal glucose meter (PGM). EDX, FTIR, and VSM results depicted that MCLIA was successfully developed and exhibits super-paramagnetism. In addition, MCLIA selectively detected the Ag⁺ at a sensitivity of 1.2 inhibition rate/μM in a linear range from 5 to 70 μM with a detection limit of 4.6 μM and IC₅₀ value of 42.3 μM. These findings strongly indicate that MCLIA is applicable as a signal platform for portable quantification of other analytes that inhibits the invertase enzyme.

Magnetite nanoparticles grafted with murexide-terminated polyamidoamine dendrimers for removal of lead (II) from aqueous solution: synthesis, characterization, adsorption and antimicrobial activity studies

In this study, new, efficient, eco-friendly and magnetically separable nanoadsorbents, MNPs-G1-Mu and MNPs-G2-Mu, were successfully prepared by covalently grafting murexide-terminated polyamidoamine dendrimers on 3-aminopropyl functionalized silica-coated magnetite nanoparticles, and used for rapid removal of lead (II) from aqueous medium. After each adsorption process, the supernatant was successfully acquired from reaction mixture by the magnetic separation, and then analyzed by employing ICP-OES. Chemical and physical characterizations of new nanomaterials were confirmed by XRD, FT-IR, SEM, TEM, and VSM. Maximum adsorption capacities (q_m) of both prepared new nanostructured adsorbents were compared with each other and also with some other adsorbents. The kinetic data were appraised by using pseudo-first-order and pseudo-second-order kinetic models. Adsorption isotherms were found to be suitable with both Langmuir and Freundlich isotherm linear equations. The maximum adsorption capacities for MNPs-G1-Mu and MNPs-G2-Mu were calculated as 208.33 mg g^-1 and 232.56 mg g^-1, respectively. Antimicrobial activities of nanoparticles were also examined against various microorganisms by using microdilution method. It was determined that MNPs-G1-Mu, MNPs-G2-Mu and lead (II) adsorbed MNPs-G2-Mu showed good antimicrobial activity against S. aureus ATTC 29213 and C. Parapsilosis ATTC 22019. MNPs-G1-Mu also showed antimicrobial activity against C. albicans ATTC 10231.

Innovative application of facile single pot green synthesized CuO and CuO@APTES nanoparticles in nanopriming of Vigna radiata seeds

Nanopriming is an emerging field of science which uses nanoparticles in solution to improve parameters of seed vigor. This leads to an initial advantage to the crop plant at the germination phase of its life cycle, which is also the most vulnerable phase and may lead to an improved yield. In this study, we have synthesized copper oxide (CuO) and (3-Aminopropyl) triethoxysilane (APTES)-coated CuO (CuO@APTES) nanoparticles via environmentally friendly green synthesis using the extract of Coriandrum sativum (coriander) herb. The synthesized nanoparticles were used as nanoprimers on Vigna radiata (moong bean), a model legume, to promote seed vigor via increase in germination. This was followed by characterization and comparison of both types of nanoparticles using various physicochemical techniques; UV-Visible (UV-Vis), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, and transmission electron microscopy (TEM). All characterization techniques pointed out to the successful synthesis and coating of CuO nanoparticles. Seed imbibition and germination assays were performed, which indicated increased imbibition potential and germination promotion at low nanoparticle concentration. Such studies can be used in the development of simple prepackaged nanoprimer products, which can be used by farmers before sowing to provide a boost to their crops and productivity.

Fabrication of copper(II)-coated magnetic core-shell nanoparticles Fe3O4@SiO2-2-aminobenzohydrazide and investigation of its catalytic application in the synthesis of 1,2,3-triazole compounds

In the present work, an attempt has been made to synthesize the 1,2,3-triazole derivatives resulting from the click reaction, in a mild and green environment using the new copper(II)-coated magnetic core-shell nanoparticles Fe3O4@SiO2 modified by isatoic anhydride. The structure of the catalyst has been determined by XRD, FE-SEM, TGA, VSM, EDS, and FT-IR analyzes. The high efficiency and the ability to be recovered and reused for at least up to 6 consecutive runs are some superior properties of the catalyst.

Kinetic Studies on the Catalytic Degradation of Rhodamine B by Hydrogen Peroxide: Effect of Surfactant Coated and Non-Coated Iron (III) Oxide Nanoparticles

Iron (III) oxide (Fe₃O₄) and sodium dodecyl sulfate (SDS) coated iron (III) oxide (SDS@Fe₃O₄) nanoparticles (NPs) were synthesized by the co-precipitation method for application in the catalytic degradation of Rhodamine B (RB) dye. The synthesized NPs were characterized using X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infra-red (FT-IR) spectroscopy techniques and tested in the removal of RB. A kinetic study on RB degradation by hydrogen peroxide (H₂O₂) was carried out and the influence of Fe₃O₄ and SDS@Fe₃O₄ magnetic NPs on the degradation rate was assessed. The activity of magnetic NPs, viz. Fe₃O₄ and SDS@Fe₃O₄, in the degradation of RB was spectrophotometrically studied and found effective in the removal of RB dye from water. The rate of RB degradation was found linearly dependent upon H₂O₂ concentration and within 5.0 × 10^-2 to 4.0 × 10^-1 M H₂O₂, the observed pseudo-first-order kinetic rates (k_obs, s^-1) for the degradation of RB (10 mg L^-1) at pH 3 and temperature 25 ± 2 °C were between 0.4 and 1.7 × 10⁴ s^-1, while in presence of 0.1% w/v Fe₃O₄ or SDS@Fe₃O₄ NPs, k_obs were between 1.3 and 2.8 × 10⁴ s^-1 and between 2.6 and 4.8 × 10⁴ s^-1, respectively. Furthermore, in presence of Fe₃O₄ or SDS@Fe₃O₄, k_obs increased with NPs dosage and showed a peaked pH behavior with a maximum at pH 3. The magnitude of thermodynamic parameters E_a and ΔH for RB degradation in presence of SDS@Fe₃O₄ were 15.63 kJ mol^-1 and 13.01 kJ mol^-1, respectively, lowest among the used catalysts, confirming its effectiveness during degradation. Furthermore, SDS in the presence of Fe₃O₄ NPs and H₂O₂ remarkably enhanced the rate of RB degradation.

Metronidazole conjugated magnetic nanoparticles loaded with amphotericin B exhibited potent effects against pathogenic Acanthamoeba castellanii belonging to the T4 genotype

Acanthamoeba castellanii can cause granulomatous amoebic encephalitis and Acanthamoeba keratitis. Currently, no single drug has been developed to effectively treat infections caused by Acanthamoeba. Recent studies have shown that drugs conjugated with nanoparticles exhibit potent in vitro antiamoebic activity against pathogenic free-living amoebae. In this study, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with metronidazole which were further loaded with amphotericin B to produce enhanced antiamoebic effects against Acanthamoeba castellanii. The results showed that metronidazole-nanoparticles-amphotericin B (Met-MNPs-Amp) significantly inhibited the viability of these amoebae as compared to the respective controls including drugs and nanoparticles alone. Met-MNPs-Amp exhibited IC₅₀ at 50 μg/mL against both A. castellanii trophozoites and cysts. Furthermore, these nanoparticles did not affect the viability of rat and human cells and showed safe hemolytic activity. Hence, the results obtained in this study have potential utility in drug development against infections caused by Acanthamoeba castellanii. A combination of drugs can lead to successful prognosis against these largely neglected infections. Future studies will determine the value of conjugating molecules with diagnostic and therapeutic potential to provide theranostic approaches against these serious infections.

Enhancement in Oral Absorption of Ceftriaxone by Highly Functionalized Magnetic Iron Oxide Nanoparticles

The present study aims at the development, characterization, biocompatibility investigation and oral bioavailability evaluation of ceftriaxone (CFT)-loaded N′-methacryloylisonicotinohydrazide (MIH)-functionalized magnetic nanoparticles (CFT-MIH-MNPs). Atomic force microscopy (AFM) and dynamic light scattering (DLS) showed that the developed CFT loaded MIH-MNPs are spherical, with a measured hydrodynamic size of 184.0 ± 2.7 nm and negative zeta potential values (–20.2 ± 0.4 mV). Fourier transformed infrared spectroscopic (FTIR) analysis revealed interactions between the nanocarrier and the drug. Nanoparticles showed high drug entrapment efficiency (EE) of 79.4% ±1.5%, and the drug was released gradually in vitro and showed prolonged in vitro stability using simulated gastrointestinal tract (GIT) fluids. The formulations were found to be highly biocompatible (up to 100 µg/mL) and hemocompatible (up to 1.0 mg/mL). Using an albino rabbit model, the formulation showed a significant enhancement in drug plasma concentration up to 14.4 ± 1.8 µg/mL in comparison with its control (2.0 ± 0.6 µg/mL). Overall, the developed CFT-MIH-MNPs formulation was promising for provision of high drug entrapment, gradual drug release and suitability for enhancing the oral delivery of CFT.

Isoniazid Conjugated Magnetic Nanoparticles Loaded with Amphotericin B as a Potent Antiamoebic Agent against Acanthamoeba castellanii

The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC₅₀ of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells.

Synthesis, Characterization, Biomedical Application, Molecular Dynamic Simulation and Molecular Docking of Schiff Base Complex of Cu(II) Supported on Fe3O4/SiO2/APTS

INTRODUCTION

Over the past several years, nano-based therapeutics were an effective cancer drug candidate in order to overcome the persistence of deadliest diseases and prevalence of multiple drug resistance (MDR).

METHODS

The main objective of our program was to design organosilane-modified Fe3O4/SiO2/APTS(~NH2) core magnetic nanocomposites with functionalized copper-Schiff base complex through the use of (3-aminopropyl)triethoxysilane linker as chemotherapeutics to cancer cells. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), TEM, and vibrating sample magnetometer (VSM) techniques. All analyses corroborated the successful synthesis of the nanoparticles. In the second step, all compounds of magnetic nanoparticles were validated as antitumor drugs through the conventional MTT assay against K562 (myelogenous leukemia cancer) and apoptosis study by Annexin V/PI and AO/EB. The molecular dynamic simulations of nanoparticles were further carried out; afterwards, the optimization was performed using MM+, semi-empirical (AM1) and Ab Initio (STO-3G), ForciteGemo Opt, Forcite Dynamics, Forcite Energy and CASTEP in Materials studio 2017.

RESULTS

The results showed that the anti-cancer activity was barely reduced after modifying the surface of the Fe3O4/SiO2/APTS nanoparticles with 2-hydroxy-3-methoxybenzaldehyde as Schiff base and then Cu(II) complex. The apoptosis study by Annexin V/PI and AO/EB stained cell nuclei was performed that apoptosis percentage of the nanoparticles increased upon increasing the thickness of Fe3O4 shell on the magnetite core. The docking studies of the synthesized compounds were conducted towards the DNA and Topoisomerase II via AutoDock 1.5.6 (The Scripps Research Institute, La Jolla, CA, USA).

CONCLUSION

Results of biology activities and computational modeling demonstrate that nanoparticles were targeted drug delivery system in cancer treatment.

Modified Fe3O4 Magnetic Nanoparticle Delivery of CpG Inhibits Tumor Growth and Spontaneous Pulmonary Metastases to Enhance Immunotherapy

As a novel toll-like receptor 9 (TLR9) agonist, synthetic unmethylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotides can stimulate a Th1 immune response and potentially be used as therapeutic agents or vaccine adjuvants for the treatment of cancer. However, some drawbacks of CpG limit their applications, such as rapid elimination by nuclease-mediated degradation and poor cellular uptake. Therefore, repeat high-dose drug administration is required for treatment. In this work, a CpG delivery system based on 3-aminopropyltriethoxysilane (APTES)-modified Fe₃O₄ nanoparticles (FeNPs) was designed and studied for the first time to achieve better bioactivity of CpG. In our results, we designed FeNP-delivered CpG particles (FeNP/CpG) with a small average size of approximately 50 nm by loading CpG into FeNPs. The FeNP/CpG particle delivery system, with enhanced cell uptake of CpG in bone marrow-derived dendritic cells (BMDCs) in vitro and through intratumoral injection, showed significant antitumor ability by stimulating better humoral and cellular immune responses in C26 colon cancer and 4T1 breast cancer xenograft models in vivo over those of free CpG. Moreover, mice treated by FeNP/CpG particles had delayed tumor growth with an inhibitory rate as high as 94.4%. In addition, approximately 50% of the tumors in the C26 model appeared to regress completely. Similarly, there were lower pulmonary metastases and a 69% tumor inhibitory rate in the 4T1 breast cancer tumor model than those in the untreated controls. In addition to their effectiveness, the easy preparation, safety, and high stability of FeNP/CpG particles also make them an attractive antitumor immunotherapy.

Synthesis of paramagnetic dendritic silica nanomaterials with fibrous pore structure (Fe3O4@KCC-1) and their application in immobilization of lipase from Candida rugosa with enhanced catalytic activity and stability

Paramagnetic mesoporous fibrous silica (Fe₃O₄@KCC-1) was prepared and its surface was functionalized with 3-aminopropyltriethoxysilane (APTES).

Chelating magnetic nanocomposite for the rapid removal of Pb(ii) ions from aqueous solutions: characterization, kinetic, isotherm and thermodynamic studies

Fe₃O₄@GMA–AAm nanocomposite as a novel adsorbent with high adsorption capacity for rapid removal of Pb²⁺ from aqueous media was synthesized.