Portable smartphone-enabled dydrogesterone sensors based on biomimetic polymers for personalized gynecological care.

Dydrogesterone, a frequently prescribed synthetic hormone integral to the treatment of diverse gynecological conditions, necessitates precise quantification in complex human plasma. In this study, the development of a portable, smartphone-based electrochemical sensor employing screen-printed gold electrodes (SPAuEs) modified with a biomimetic, molecularly imprinted poly(methacrylic acid-co-methyl methacrylate) (MIP) is presented for dydrogesterone detection in human plasma. FTIR spectroscopy illustrates the transformation of a pre-polymer mixture into a polymerized matrix, while SEM reveals a uniform MIP/SPAuE surface morphology. The sensor fabrication protocol, encompassing MIP/SPAuE composition, polymerization solvent, incubation time, and scan rate, is optimized to achieve enhanced sensitivity. The MIP/SPAuEs sensor exhibits a linear sensor response to dydrogesterone within the concentration range of 1-500 nM, as evidenced by cyclic and differential pulse voltammetry. The MIP/SPAuE sensor demonstrates exceptional sensitivity, recording 8.2 × 10-3 µA nM-1, with a sub-nanomolar limit of detection (LOD = 370 pM), and low limit of quantification (LOQ = 1.12 nM), along with appreciable selectivity over common interferents. In real-world clinical applications, the designed sensor is effectively employed for the rapid and precise determination of dydrogesterone in human blood plasma, achieving a remarkable recovery of 81%. Furthermore, MIP/SPAuE coatings possess suitable stability over 15 days, indicating the robustness of the sensor material for multiple rounds of analysis. The developed sensor provides a sensitive, selective, and cost-effective solution for monitoring dydrogesterone in plasma during various gynecological disorders, allowing for personalized healthcare applications.

Cupric oxide nanoparticles incorporated poly(hydroxybutyrate) nanocomposite for potential biosensing application.

We report the synthesis of a novel electrochemical biosensor comprising of cupric oxide (CuO) nanoparticles (NPs) mediated poly(hydroxybutyrate) (PHB) composite film with polyvinyl alcohol (PVA) as a binder/template support using the solution casting method for the detection of a biomolecule i.e., ascorbic acid (AA). The specimens were characterized for surface, chemical, mechanical, optical, and electrochemical attributes. The results expressed regular mediation of CuO NPs in the PHB/PVA matrix towards nanobiocomposite formation with enhanced crystallinity, inter-molecular interactions, mechanical, and electrochemical attributes, and decreased hydrophilicity and bandgap, thus being useful in potential optoelectronic devices. The synthesized biocomposite film exhibited a tensile strength of 86.24 ± 4.10 N which might be due to reinforcement/uniform dispersion of the CuO nanofiller in the PHB-based matrix. The PHB/CuO composite, then, deposited on a glassy carbon electrode surface exhibited good electrocatalytic activity towards the AA in the aqueous media even at low analyte concentrations. Such modified electrode surfaces with metal/biopolymer complex could find possible applications in the detection of other bioactive molecules.

Development of a LAMP assay using a portable device for the real-time detection of cotton leaf curl disease in field conditions.

Cotton production is seriously affected by the prevalent cotton leaf curl disease (CLCuD) that originated from Nigeria (Africa) to various parts of Asia including Pakistan, India, China and Philippines. Due to CLCuD, Pakistan suffers heavy losses approximately 2 billion USD per annum. Numerous reports showed that CLCuD is associated with multiple species of begomoviruses, alphasatellites and a single species of betasatellite, that is 'Cotton leaf curl Multan betasatellite' (CLCuMuB). The most prevalent form of CLCuD is the combination of 'Cotton leaf curl Kokhran virus'-Burewala strain (CLCuKoV-Bur) and CLCuMuB. Thus, the availability of an in-field assay for the timely detection of CLCuD is important for the control and management of the disease. In this study, a robust method using the loop-mediated isothermal amplification (LAMP) assay was developed for the detection of CLCuD. Multiple sets of six primers were designed based on the conserved regions of CLCuKoV-Bur and CLCuMuB-ßC1 genes. The results showed that the primer set targeting the CLCuMuB-ßC1 gene performed best when the LAMP assay was performed at 58°C using 100 ng of total plant tissue DNA as a template in a 25 µl reaction volume. The limit of detection for the assay was as low as 22 copies of total purified DNA template per reaction. This assay was further adapted to perform as a colorimetric and real-time LAMP assay which proved to be advantageously applied for the rapid and early point-of-care detection of CLCuD in the field. Application of the assay could help to prevent the huge economic losses caused by the disease and contribute to the socio-economic development of underdeveloped countries.

Molecularly imprinted polymeric coatings for sensitive and selective gravimetric detection of artemether.

Monitoring antimalarial drugs is necessary for clinical assays, human health, and routine quality control practices in pharmaceutical industries. Herein, we present the development of sensor coatings based on molecularly imprinted polymers (MIPs) combined with quartz crystal microbalance (QCM) for sensitive and selective gravimetric detection of an antimalarial drug: artemether. The MIP coatings are synthesized by using artemether as the template in a poly(methacrylic acid-co-ethylene glycol dimethacrylate) matrix. Artemether-MIP and the non-imprinted polymer (NIP) control or reference layers are deposited on 10 MHz dual-electrode QCM by spin coating (187 ± 9 nm layer thickness after optimization). The coatings are characterized by FTIR spectroscopy and atomic force microscopy that reveal marked differences among the MIP and NIP. The MIP-QCM sensor exhibits high sensitivity (0.51 Hz ppm-1) with sub-10 ppm detection and quantification limits. The MIP-QCM sensor also exhibits a 6-fold higher sensitivity compared to the NIP-QCM, and a dynamic working range of 30-100 ppm. The response time of MIP-QCM devices for a single cycle of analyte adsorption, signal saturation, and MIP regeneration is less than 2.5 min. The sensor also demonstrates selectivity factors of artemether-MIP of 2.2 and 4.1 compared to artemisinin and lumefantrine, respectively. Reversibility tests reveal less than 5% variation in sensor responses over three cycles of measurements at each tested concentration. The MIP-QCM showed lower detection limits than conventional HPLC-UV, and faster response time compared to HPLC-UV and liquid chromatography-mass spectrometry (LC-MS).

Synthesis of SPIONs-CNT Based Novel Nanocomposite for Effective Amperometric Sensing of First-Line Antituberculosis Drug Rifampicin.

It is necessary to study the possible interactions among various chemical surfaces and analytes before applying them to biological systems. We report the synthesis of carbon nanotubes-iron oxide (SPIONs-CNT) nanocomposite material by using lecithin stabilized superparamagnetic iron oxide nanoparticles (SPIONs) obtained by facile hydrothermal technique. Various characterizations of the obtained nanocomposite were carried out and electrochemical studies were performed further to study the interaction capabilities of the nanocomposite with anti-TB drug Rifampicin. Obtained results by cyclic voltammetric studies of SPIONs-CNT nanocomposite with limit of detection (LOD) of 1.178 µM showed the enhanced electrochemical sensitivity and selectivity of anti-tuberculosis (anti-TB) drug Rifampicin (RIF).

Assessment of Antimicrobial Features of Selenium Nanoparticles (SeNPs) Using Cyclic Voltammetric Strategy.

The emerging biomedical applications of selenium nanoparticles (SeNPs) require facile and efficient strategy to assess its interactions with cell membrane. In this study, an efficient and reproducible microwave assisted method was used to synthesize SeNPs with controllable size distributions. The physical properties of the emergent structures, such as morphology, structure, and size were studied. The antimicrobial applications of SeNPs were assessed by electrochemical analyses that entailed the systematic acquisition of cyclic voltammetry data. Our results demonstrate a straightforward method to predict the integrity of bacterial cell membranes following the administration of SeNP treatments.

Nanoparticle-based Point of Care Immunoassays for in vitro Biomedical Diagnostics.

In resource-limited settings, the availability of medical practitioners and early diagnostic facilities are inadequate relative to the population size and disease burden. To address cost and delayed time issues in diagnostics, strip-based immunoassays, e.g. dipstick, lateral flow assay (LFA) and microfluidic paper-based analytical devices (microPADs), have emerged as promising alternatives to conventional diagnostic approaches. These assays rely on chromogenic agents to detect disease biomarkers. However, limited specificity and sensitivity have motivated scientists to improve the efficiency of these assays by conjugating chromogenic agents with nanoparticles for enhanced qualitative and quantitative output. Various nanomaterials, which include metallic, magnetic and luminescent nanoparticles, are being used in the fabrication of biosensors to detect and quantify biomolecules and disease biomarkers. This review discusses some of the principles and applications of such nanoparticle-based point of care biosensors in biomedical diagnosis.

Fluorescence Guided Sentinel Lymph Node Mapping: From Current Molecular Probes to Future Multimodal Nanoprobes.

For SLN lymph node biopsy (SLNB), SLN mapping has become a standard of care procedure that can accurately locate the micrometastases disseminated from primary tumor sites to the regional lymph nodes. The broad array of SLN mapping has prompted the development of a wide range of SLN tracers, rationally designed for noninvasive and high-resolution imaging of SLNs. At present, conventional SLN imaging probes (blue dyes, radiocolloids, and few other small-molecular dyes), although serving the clinical needs, are often associated with major issues such as insufficient accumulation in SLN, short retention time, staining of the surgical field, and other adverse side effects. In a recent advancement, newly designed fluorescent nanoprobes are equipped with novel features that could be of high interest in SLN mapping such as (i) a unique niche that is not met by any other conventional SLN probes, (ii) their adoptable synthesis method, and (ii) excellent sensitivity facilitating high resolution SLN mapping. Most importantly, lots of effort has been devoted for translating the fluorescent nanoprobes into a clinical setup and also imparting the multimodal imaging abilities of nanoprobes for the excellent diagnosis of life-threatening diseases such as cancer. In this review, we will provide a detailed roadmap of the progress of a wide variety of current fluorescent molecular probes and emphasize the future of nanomaterial-based single/multimodal imaging probes that have true potential translation abilities for SLN mapping.

Biosurfactant coated silver and iron oxide nanoparticles with enhanced anti-biofilm and anti-adhesive properties.

Pseudomonas aeruginosa and Staphylococcus aureus are among the hazardous biofilm forming bacteria ubiquitous in industrial/clinical wastes. Serious efforts are required to develop effective strategies to control surface-growing antibiotic resistant pathogenic bacterial communities which they are emerging as a global health issue. Blocking hazardous biofilms would be a useful aspect of biosurfactant coated nanoparticles (NPs). In this regard, we report a facile method for the synthesis of rhamnolipid (RL) coated silver (Ag) and iron oxide (Fe3O4) NPs and propose the mechanism of their synergistic antibacterial and anti-adhesive properties against biofilms formed by P. aeruginosa and S. aureus. These NPs demonstrated excellent anti-biofilm activity not only during the biofilms formation but also on the pre-formed biofilms. Mechanistically, RL coated silver (35 nm) and Fe3O4 NPs (48 nm) generate reactive oxygen species, which contribute to the antimicrobial activity. The presence of RLs shell on the nanoparticles significantly reduces the cell adhesion by modifying the surface hydrophobicity and hence enhancing the anti-biofilm property of NPs against both mentioned strains. These findings suggest that RL coated Ag and Fe3O4 NPs may be used as potent alternate to reduce the infection severity by inhibiting the biofilm formation and, therefore, they possess potential biomedical applications for antibacterial coatings and wound dressings.

Hollow mesoporous hydroxyapatite nanostructures; smart nanocarriers with high drug loading and controlled releasing features.

We report the development of effective drug loaded nanocarriers to combat multidrug resistant infection especially in case of osteomyelitis. The hollow mesoporous hydroxyapatite nanoparticles (hmHANPs) and solid/non-hollow hydroxyapatite nanoparticles (sHANPs) were synthesized by core-shell and co-precipitation techniques respectively. High encapsulation of the drug (ciprofloxacin) was observed in hmHANPs as compared to sHANPs, which may be due to the hollow porous structure of hmHANPs. These nanoparticles were characterized by scanning electron microscope (FESEM), N2 adsorption/desorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). Approximately 80% of the encapsulated drug was released at pH 4.5 within 5 days in case of hmHANPs while at pH 7.4, a sustained drug release profile was obtained and only 48.73% of the drug was released after 9 days. The results of kinetic drug release revealed that drug loaded hmHANPs showed fickian diffusion and anomalous drug diffusion mechanism at pH 4.5 and 7.4 respectively. Owing to their porous structure and high drug loading capacity, hmHANPs showed enhanced antibacterial activity against Staphylococcus aureus and Escherichia coli (drug resistant strains of osteomyelitis) in comparison to that with sHANPs. In addition, hmHANPs showed a pH sensitive drug release profile, high surface area (105.33 m2/g) with increased pore volume (0.533 cm3/g) and superior antimicrobial activity against osteomyelitis as compared to sHANPs.

Lecithin-coated gold nanoflowers (GNFs) for CT scan imaging applications and biochemical parameters; in vitro and in vivo studies.

We report a novel strategy for the fabrication of lecithin-coated gold nanoflowers (GNFs) via single-step design for CT imaging application. Field-emission electron microscope confirmed flowers like morphology of the as-synthesized nanostructures. Furthermore, these show absorption peak in near-infrared (NIR) region at λmax 690 nm Different concentrations of GNFs are tested as a contrast agent in CT scans at tube voltage 135 kV and tube current 350 mA. These results are compared with same amount of iodine at same CT scan parameters. The results of in vitro CT scan study show that GNFs have good contrast enhancement properties, whereas in vivo study of rabbits CT scan shows that GNFs enhance the CT image clearly at 135 kV as compared to that of iodine. Cytotoxicity was studied and blood profile show minor increase of white blood cells and haemoglobin, whereas decrease of red blood cells and platelets.

Solid lipid nanoparticles for thermoresponsive targeting: evidence from spectrophotometry, electrochemical, and cytotoxicity studies.

Thermoresponsive drug delivery systems are designed for the controlled and targeted release of therapeutic payload. These systems exploit hyperthermic temperatures (>39°C), which may be applied by some external means or due to an encountered symptom in inflammatory diseases such as cancer and arthritis. The objective of this paper was to provide some solid evidence in support of the hypothesis that solid lipid nanoparticles (SLNs) can be used for thermoresponsive targeting by undergoing solid-liquid phase transition at their melting point (MP). Thermoresponsive lipid mixtures were prepared by mixing solid and liquid natural fatty acids, and their MP was measured by differential scanning calorimetry (DSC). SLNs (MP 39°C) containing 5-fluorouracil (5-FU) were synthesized by hot melt encapsulation method, and were found to have spherical shape (transmission electron microscopy studies), desirable size (<200 nm), and enhanced physicochemical stability (Fourier transform infrared spectroscopy analysis). We observed a sustained release pattern (22%-34%) at 37°C (5 hours). On the other hand, >90% drug was released at 39°C after 5 hours, suggesting that the SLNs show thermoresponsive drug release, thus confirming our hypothesis. Drug release from SLNs at 39°C was similar to oleic acid and linoleic acid nanoemulsions used in this study, which further confirmed that thermoresponsive drug release is due to solid-liquid phase transition. Next, a differential pulse voltammetry-based electrochemical chemical detection method was developed for quick and real-time analysis of 5-FU release, which also confirmed thermoresponsive drug release behavior of SLNs. Blank SLNs were found to be biocompatible with human gingival fibroblast cells, although 5-FU-loaded SLNs showed some cytotoxicity after 24 hours. 5-FU-loaded SLNs showed thermoresponsive cytotoxicity to breast cancer cells (MDA-MB-231) as cytotoxicity was higher at 39°C (cell viability 72%-78%) compared to 37°C (cell viability >90%) within 1 hour. In conclusion, this study presents SLNs as a safe, simple, and effective platform for thermoresponsive targeting.

Investigating the potential of multiwalled carbon nanotubes based zinc nanocomposite as a recognition interface towards plant pathogen detection.

The emergence of nanotechnology has opened new horizons for constructing efficient recognition interfaces. This is the first report where the potential of a multiwalled carbon nanotube based zinc nanocomposite (MWCNTs-Zn NPs) investigated for the detection of an agricultural pathogen i.e. Chili leaf curl betasatellite (ChLCB). Atomic force microscope analyses revealed the presence of multiwalled carbon nanotubes (MWCNTs) having a diameter of 50-100nm with zinc nanoparticles (Zn-NPs) of 25-500nm. In this system, these bunches of Zn-NPs anchored along the whole lengths of MWCNTs were used for the immobilization of probe DNA strands. The electrochemical performance of DNA biosensor was assessed in the absence and presence of the complementary DNA during cyclic and differential pulse voltammetry scans. Target binding events occurring on the interface surface patterned with single-stranded DNA was quantitatively translated into electrochemical signals due to hybridization process. In the presence of complementary target DNA, as the result of duplex formation, there was a decrease in the peak current from 1.89×10-04 to 5.84×10-05A. The specificity of this electrochemical DNA biosensor was found to be three times as compared to non-complementary DNA. This material structuring technique can be extended to design interfaces for the recognition of the other plant viruses and biomolecules.

Novel route synthesis of porous and solid gold nanoparticles for investigating their comparative performance as contrast agent in computed tomography scan and effect on liver and kidney function.

Gold nanoparticles (GNPs) with dimension in the range of 1-100 nm have a prominent role in a number of biomedical applications like imaging, drug delivery, and cancer therapy owing to their unique optical features and biocompatibility. In this work, we report a novel technique for the synthesis of two types of GNPs namely porous gold nanoparticles (PGNPs) and solid gold nanoparticles (SGNPs). PGNPs of size 35 nm were fabricated by reduction of gold (III) solution with lecithin followed by addition of L-ascorbic acid and tri-sodium citrate, whereas SGNPs with a dimension of 28 nm were prepared by reflux method using lecithin as a single reducing agent. Comparative studies using PGNPs (λmax 560 nm) and SGNPs (λmax 548 nm) were conducted for evaluating their use as a contrast agent. These studies reveled that in direct computed tomography scan, PGNPs exhibited brighter contrast (45 HU) than SGNPs (26 HU). To investigate the effect of PGNPs and SGNPs on the liver and kidney profile, male rabbits were intravenously injected with an equal dose of 1 mg/kg weight of PGNPs and SGNPs. The effect on biochemical parameters was evaluated 72 hours after intravenous (IV) injection including liver function profile, renal (kidney) function biomarker, random blood glucose value, and cholesterol level. During one comparison of contrast in CT scan, PGNPs showed significantly enhanced contrast in whole-rabbit and organ CT scan as compared to SGNPs 6 hours after injection. Our findings suggested that the novel PGNPs enhance CT scan image with higher efficacy as compared to SGNPs. The results showed that IV administration of synthesized PGNPs increases the levels of aspartate aminotransferase (AST), alkaline phosphate (ALP), serum creatinine, and blood glucose, whereas that of SGNPs increases the levels of AST, ALP, and blood glucose.

Developing imprinted polymer nanoparticles for the selective separation of antidiabetic drugs.

In this study, new molecularly imprinted polymer (MIP) nanoparticles are designed for selective recognition of different drugs used for the treatment of type 2 diabetes mellitus, i.e. sitagliptin (SG) and metformin (MF). The SG- and MF-imprinted polymer nanoparticles are synthesized by free-radical initiated polymerization of the functional monomers: methacrylic acid and methyl methacrylate; and the crosslinker: ethylene glycol dimethacrylate. The surface morphology of resultant MIP nanoparticles is studied by atomic force microscopy. Fourier transform infrared spectra of MIP nanoparticles suggest the presence of reversible, non-covalent interactions between the template and the polymer. The effect of pH on the rebinding of antidiabetic drugs with SG- and MF-imprinted polymers is investigated to determine the optimal experimental conditions. The molecular recognition characteristics of SG- and MF-imprinted polymers for the respective drug targets are determined at low concentrations of SG (50-150 ppm) and MF (5-100 ppm). In both cases, the MIP nanoparticles exhibit higher binding response compared to non-imprinted polymers. Furthermore, the MIPs demonstrate high selectivity with four fold higher responses toward imprinted drugs targets, respectively. Recycled MIP nanoparticles retain 90% of their drug-binding efficiency, which makes them suitable for successive analyses with significantly preserved recognition features.

Solid and liquid lipid-based binary solid lipid nanoparticles of diacerein: in vitro evaluation of sustained release, simultaneous loading of gold nanoparticles, and potential thermoresponsive behavior.

Binary fatty acid mixture-based solid lipid nanoparticles (SLNs) were prepared for delivery of diacerein, a novel disease-modifying osteoarthritis drug, with and without simultaneously loaded gold nanoparticles (GNPs). In order to optimize SLNs for temperature-responsive release, lipid mixtures were prepared using different ratios of solid (stearic acid or lauric acid) and liquid (oleic acid) fatty acids. SLNs were prepared by microemulsification (53 nm), hot melt encapsulation (10.4 nm), and a solvent emulsification-evaporation technique (7.8 nm). The physicochemical characteristics of SLNs were studied by Zetasizer, Fourier transform infrared, and X-ray diffraction analysis. High encapsulation of diacerein was achieved with diacerein-loaded and simultaneously GNP-diacerein-loaded SLNs. In vitro dissolution studies revealed a sustained release pattern for diacerein over 72 hours for diacerein-loaded SLNs and 12 hours for GNP-diacerein-loaded SLNs. An increase in diacerein payload increased the release time of diacerein while GNPs decreased it. In addition, rapid release of diacerein over 4 hours was observed at 40°C (melting point of optimized fatty acid mixture), demonstrating that these binary SLNs could be used for thermoresponsive drug delivery. Kinetic modeling indicated that drug release followed zero order and Higuchi diffusion models (R(2)>0.9), while the Korsmeyer-Peppas model predicted a diffusion release mechanism (n<0.5).

Nanostructured materials with biomimetic recognition abilities for chemical sensing.

Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The 'harder' MoS2 yields only about 40% of the signals towards octane thiol as compared to the 'softer' Cu2S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.