jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Timo Froyen | Niels Geysmans | Ulrique Vounckx | An Hardy
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2021-02-26)
Field: Materials Science — Materials Chemistry

Multilamellar mesoporous silica nanoparticles using a cationic co-surfactant dual-templating method ABSTRACT The utility of mesoporous silica nanoparticles (MSNs) has been repeatedly proven in a wide range of biomedical applications. The general morphology of these particles is easily modifiable by various post-grafting possibilities and adjustments within the surfactant-based template. The synthesis of multilamellar vesicular silica nanoparticles has led to the discovery of beneficial attributes regarding said particles. Depending on the synthesis process, various parameters are affected including packaging capacity, stability, drug adsorption and release. This research focused on synthesis and characterization of multilamellar MSNs using a cationic-cationic co-surfactant templating route testing various ratios of cetyltrimethylammonium bromide (CTAB) and didodecyldimethylammonium bromide (DDAB). TEM imaging showed clear differences in size and morphology between the different samples, and was further characterized by BET and BJH analysis. All multilamellar nanoparticles did exhibit a similar pore size distribution and overall gradual release of drug contents. However, the degree of drug adsorption and overtime drug release was clearly influenced by the number of layers of the MSNs, proving the utility of adjusting the template. Further experiments could be conducted to validate the utility of beta-cyclodextrin as a template regulator and to investigate both biocompatibility and biodegradability of the multilamellar MSNs. Cationic polymerization ; Mesoporous silica ; Nanoparticle ; Bromide ; Pulmonary surfactant ; Chemical engineering ; Mesoporous material ; Materials science ; Adsorption ; Nanotechnology ; Biocompatibility ; Micelle ; Drug delivery ; Chemistry ; Organic chemistry ; Polymer chemistry ; Aqueous solution ; Catalysis Mesoporous Materials and Catalysis ; Nanoparticle-Based Drug Delivery ; Surfactants and Colloidal Systems
Authors: M. H. Badr | M. H. Nasr | M. M. Elkholy | L.M. Sharaf El-Deen | Gamal Turky | Mohamed Moustafa | A. S. Abouhaswa | A. A. EL Hamalawy
Source: Research Square (preprint, 2021-08-12)
Field: Materials Science — Materials Chemistry

Investigation of Crystal Structure, Electrical and Magnetic Properties of Spinel Mn-Cd Ferrite Nanoparticles Abstract Fe2Cd1-xMnxO4 (x= 0, 0.25, 0.5, 0.75, 1) spinel ferrite nanoparticle samples were synthesized using a flash auto-combustion technique and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The inspection of dielectric and magnetic properties of the prepared ferrites was carried out by using broadband dielectric spectroscopy (BDS) and vibration sample magnetometer (VSM) measurements, respectively. X-ray diffraction analysis verified the formation of the main cubic phase with space group Fd3m and a decrease in lattice constants with the increase in Mn-content. FTIR study revealed the two characteristic absorption bands of spinel ferrites and their dependence on Mn-content was investigated and explained. Elastic moduli such as Longitudinal, transverse and mean elastic wave velocities (𝑉𝑙 , 𝑉𝑡 𝑉𝑚), bulk modulus (𝐵), rigidity modulus (𝐺), Young modulus (𝐸) and calculated Debye temperature (θD) have been studied and found to decrease with the increase in Mn-content. SEM analysis revealed nanoparticles agglomeration of uniform grains with increasing in the average grain size as Mn-content increased. The VSM measurements showed an increase in saturation magnetization (Ms) accompanied by a decrease in coercivity (Hc) as Mn-content increased. Dielectric investigations showed very high values of permittivity and dielectric loss at lower frequencies reflecting the combination of exchange of electrons between ferrous and ferric ions and ions’ transport. The ac-conductivity showed a plateau that yields the dc-conductivity (σdc) at lower frequencies followed by a characteristic frequency (νc) at which it tends out to follow a power law. The relation between these two parameters confirms the empirical BNN-relation. Materials science ; Analytical Chemistry (journal) ; Dielectric ; Coercivity ; Spinel ; Ferrite (magnet) ; Fourier transform infrared spectroscopy ; Dielectric loss ; Scanning electron microscope ; Nuclear magnetic resonance ; Mineralogy ; Condensed matter physics ; Composite material ; Chemistry ; Optics ; Metallurgy Magnetic Properties and Synthesis of Ferrites ; Magnetic Properties and Applications ; Magneto-Optical Properties and Applications
Authors: Janesline Fernandes | Teotone Vaz | S. M. Gurav | Tushar Anvekar
Source: Journal of Scientific Research (article, 2021-09-01)
Field: Materials Science — Biomaterials

Polymeric Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; Conjugates with Bioactive Plant Molecules: Platforms for Antimicrobial Therapy The emerging nano biosystems are competent in diagnosis, drug delivery, and monitoring of therapeutic response. Both imaging and therapeutic functions can be achieved by using nanoplatforms. These nanoplatforms promise to revolutionize the medical management of many personalized illnesses. The well-developed surface chemistry of iron oxide (Fe3O4) makes it easy to charge them with pharmaceutics, promoting them as nanoplatforms for building up nanoparticle-based drug delivery systems. The strategy to design multifunctional Fe3O4 conjugates with bioactive molecules of plant origin to show enhanced activity is reported here. The conjugation reveals the magnetic Fe3O4 core nanoparticle surface readily link to hydroxyl sites of the Dextrin molecule, which further conjugate to conjugated with Curcumin and D-Limonene, which are powerful anti-cancer, anti-inflammatory, and antioxidant agents. The structural, morphological, optical, and magnetic properties were analyzed by X-ray diffraction, FT-Infrared, HR-Tunneling Electron Microscopy, and Vibrating Sample Magnetometer techniques. The potential drug loading was measured as Drug Entrapment Efficiency using UV-Vis spectroscopy. The antibacterial property was tested on the bacterium S. aureus and E. coli. Fe3O4-Dextrin nanoconjugates proved to be efficient for loading and stabilizing Curcumin and Limonene. Thus, multifunctional Fe3O4 conjugates are explored as exciting nano-drug carriers for targeted drug delivery. Conjugate ; Drug delivery ; Conjugated system ; Nanotechnology ; Curcumin ; Nanoparticle ; Molecule ; Chemistry ; Combinatorial chemistry ; Materials science ; Targeted drug delivery ; Organic chemistry ; Polymer ; Biochemistry Nanoparticle-Based Drug Delivery
Authors: Gökhan Demirci | Malwina Niedźwiedź | Nina Kantor-Malujdy | Mirosława El Fray
Source: Preprints.org (preprint, 2021-06-01)
Field: Materials Science — Biomaterials

Bio-Inspired Polymer-Polymer Hybrids for Medical Applications Novel bio-inspired materials have gained recently great attention, especially in medical applications. Applying sophisticated design and engineering methods, various polymer-polymer hybrid systems with outstanding performance have been developed in last decades. Hybrid systems composed of bioelastomers and hydrogels are very attractive due to their high biocompatibility and elastic nature for advanced biomaterials used in various medical applications such as drug delivery systems and scaffolds for tissue engineering. Herein, we describe the advances in current state-of-the-art design, properties and applications of polymer-polymer hybrid systems in medical applications. Bio-inspired functionalities, including bioadhesiveness, injectability, antibacterial properties and degradability applicable to advanced drug delivery systems and medical devices will be discussed in a context of future efforts towards development of bioinspired materials. Drug delivery ; Biocompatibility ; Nanotechnology ; Self-healing hydrogels ; Context (archaeology) ; Tissue engineering ; Materials science ; Polymer ; Hybrid system ; Computer science ; Systems engineering ; Engineering ; Biomedical engineering biodegradable polymer synthesis and properties ; Bone Tissue Engineering Materials ; 3D Printing in Biomedical Research
Authors: Hassnain Asgar | Sohaib Mohammed | Söenke Seifert | Greeshma Gadikota
Source: Energy & Fuels (article, 2021-11-22)
Field: Chemistry — Organic Chemistry

Structure and Shape of Surface-Mediated Assembly of Surfactants Achieving controls on the self-assembly of cationic and block copolymer micelles has significant implications for advancing novel material systems for energy, environmental, and biological applications and for tuning fluid flow behavior in subsurface geologic environments. While it is known that the aggregation of micelles is influenced by the composition of the surrounding fluid, the influence of a solid interface has been less explored. In this study, we probe the organization of cetyltrimethylammonium bromide (CTAB) micelles in the absence and presence of the Pluronic P123 block copolymer and quartz substrate using transmission and grazing-incidence small-angle X-ray scattering measurements and classical molecular dynamics (MD) simulations. In the absence of the quartz interface, CTAB with and without P123 molecules assemble as ellipsoid core–shell micelles. Densification of the core on adding P123 is noted from the decrease in the core radius from 15.9 to 14.6 Å. The presence of a quartz substrate causes the micelles to elongate, which is noted by the emergence of a power-law slope in the low q region (<0.02 Å–1). Moreover, in the presence of both P123 and the quartz substrate, the micelle shape changes from ellipsoid core–shell to cylindrical core–shell, and a significantly higher number of aggregates are formed. The higher number of aggregates, and faster aggregation kinetics are linked to the organization of the solvent structures as noted from the MD simulations. These findings demonstrate the effects of adding a block copolymer and including a quartz substrate on the self-assembly of cationic (CTAB) micelles, which can be used to inform the design of functional material systems that harness surfactant chemistries. Micelle ; Copolymer ; Cationic polymerization ; Quartz ; Chemical engineering ; Chemical physics ; Materials science ; Hydrodynamic radius ; Substrate (aquarium) ; Chemistry ; Polymer chemistry ; Polymer ; Composite material ; Physical chemistry ; Aqueous solution ; Geology Surfactants and Colloidal Systems ; Pickering emulsions and particle stabilization ; Enhanced Oil Recovery Techniques
Authors: Lili He | Lijuan Zhai | Jian Sun | Jingwen Ji | Jinbo Ji | Yuanbai Liu | Yangxiu Mu | Yuanyu Gao | Dong Tang | Rui Jiang | Ko Ko Myo | Zaw Min Thu | Haikang Yang | Zafar Iqbal | Zhixiang Yang
Source: Journal of Chemistry (article, 2021-07-28)
Field: Chemistry — Organic Chemistry

Substituted-Amidine Functionalized Monocyclic β-Lactams: Synthesis and In Vitro Antibacterial Profile Background. Owing to the intrinsic stability against common β-lactamases and metallo-lactamases, monobactams gathered special attention in antibiotic drug development. However, so far, aztreonam is the only monobactam approved by FDA for clinical use. We designed new derivatives of aztreonam to enhance its antibacterial efficacy. Methods. We synthesized a series of monocyclic β-lactams by modifying mainly at the C3 position of azetidinone ring. NH2 group at C3 of azetidinone was attached to thiazole and thiadiazole which in turn was linked to nitrogenous heterocyclic rings via amidine moieties. We then investigated the in vitro antibacterial activities of synthesized compounds against ten bacterial strains of clinical interest in comparison to aztreonam and ceftazidime. Results. All compounds showed improved antibacterial activities against tested strains compared to reference drugs. Compounds 14d and 14e were most potent and showed the highest potency against all bacterial strains, with MIC values ranging from 0.25 µg/mL to 8 µg/mL, as compared to aztreonam (MIC 16 µg/mL to &gt;64 µg/mL) and ceftazidime (MIC &gt;64 µg/mL). These compounds (14d and 14e) may be valuable lead targets against multidrug-resistant Gram-negative bacteria. Aztreonam ; Chemistry ; Ceftazidime ; Antibacterial activity ; Amidine ; Potency ; Thiazole ; Antibiotics ; Antibacterial agent ; In vitro ; Stereochemistry ; Combinatorial chemistry ; Bacteria ; Biochemistry ; Antibiotic resistance ; Biology Synthesis of β-Lactam Compounds ; Antibiotic Resistance in Bacteria ; Antibiotics Pharmacokinetics and Efficacy
Authors: Sylvestre P. J. T. Bachollet | Yuriy Shpinov | Fanny Broch | Hela Benaissa | Arnaud Gautier | Jean‐Maurice Mallet | Blaise Dumat
Source: ChemRxiv (preprint, 2021-11-19)
Field: Chemistry — Spectroscopy

An expanded palette of fluorogenic HaloTag probes with enhanced contrast for targeted cellular imaging We report on new fluorogenic HaloTag probes based on a molecular rotor design. Thanks to their viscosity-sensitive emission, the probes light-up upon reaction with the protein self-labeling tag HaloTag. The palette of probes cover an emission range from green to red and exhibit remarkably low non-specific signal that enabled wash-free targeted imaging of intracellular organelles and proteins with good contrast in live Hela cells. Palette (painting) ; Chemistry ; Biophysics ; HeLa ; Molecular probe ; Organelle ; Intracellular ; Nanotechnology ; Materials science ; Cell ; Biochemistry ; DNA ; Biology Molecular Sensors and Ion Detection ; Luminescence and Fluorescent Materials ; Nanoplatforms for cancer theranostics
Authors: Ainash Garifullina | Amy Q. Shen
Source: Journal of Materials Chemistry B (article, 2021-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

High-throughput fabrication of high aspect ratio Ag/Al nanopillars for optical detection of biomarkers Nanomaterial-based optical techniques for biomarker detection have garnered tremendous attention from the nanofabrication community due to their high precision and enhanced limit of detection (LoD) features. These nanomaterials are highly responsive to local refractive index (RI) fluctuations, and their RI unit sensitivity can be tuned by varying the chemical composition, geometry, and dimensions of the utilized nanostructures. To improve the sensitivity and LoD values of these nanomaterials, it is common to increase both dimensions and aspect ratios of the fabricated nanostructures. However, limited by the complexity, prolonged duration, and elevated costs of the available nanofabrication techniques, mass production of these nanostructures remains challenging. To address not only high accuracy, but also speed and production effectiveness in these nanostructures' fabrication, our work reports, for the first time, a fast, high-throughput, and cost-effective nanofabrication protocol for routine manufacturing of polymer-based nanostructures with high sensitivity and calculated LoD in the pM range by utilizing anodized aluminum oxide (AAO) membranes as templates. Specifically, our developed platform consists of arrays of nearly uniform polystyrene nanopillars with an average diameter of ∼185 nm and aspect ratio of ∼11. We demonstrate that these nanostructures can be produced at a high speed and a notably low price, and that they can be efficiently applied for biosensing purposes after being coated with aluminum-doped silver (Ag/Al) thin films. Our platform successfully detected very low concentrations of human C-reactive protein (hCRP) and SARS-CoV-2 spike protein biomarkers in human plasma samples with LoDs of 11 and 5 pM, respectively. These results open new opportunities for day-to-day fabrication of high aspect ratio arrays of nanopillars that can be used as a base for nanoplasmonic sensors with competitive LoD values. This, in turn, contributes to the development of point-of-care devices and further improvement of the existing nanofabrication techniques, thereby enriching the fields of pharmacology, clinical analysis, and diagnostics. Nanopillar ; Materials science ; Fabrication ; Throughput ; Nanotechnology ; Aspect ratio (aeronautics) ; Optoelectronics ; Nanostructure ; Computer science ; Medicine ; Telecommunications Gold and Silver Nanoparticles Synthesis and Applications ; Nanowire Synthesis and Applications ; Advanced biosensing and bioanalysis techniques
Authors: Renuka Tanmay Gupta
Source:  (preprint, 2021-05-22)
Field: Materials Science — Materials Chemistry

Surface-active solid lipid nanoparticles for emulsion stabilization Solid lipid nanoparticles (SLNs) consisting of the food grade surfactant lipid glyceryl stearate citrate (GSC) were prepared using hot melt emulsification and high-pressure homogenization. Flash-cooling of the resultant oil-in-water nanoemulsions led to the formation of GSC SLNs. The effective mean particle size of the SLNs was ~180 nm by dynamic light scattering and the volume-weighted mean particle size was ~152 nm by laser diffraction, with a zeta (ζ) potential of ~-49 mV. Effective mean particle size and ζ potential were stable for 24 wk. An equilibrium contact angle of ~108.7⁰ measured through oil phase was obtained, suggesting a wettable lipid surface. The melting curve of the SLNs obtained by differential scanning calorimetry showed a significantly lower melting point and broader peak as compared to the bulk GSC, which was attributed to the nano-scale particle size. Unusually, the cooling curve showed an identical crystallization temperature as that for the bulk GSC, which suggested surface heterogeneous crystallization of the SLNs. Subsequent heating-cooling cycles confirmed the existence of nanosized particles in the sample during thermal analysis. Transmission electron (TEM) and atomic force microscopy (AFM) both revealed anisometric, flattened SLNs with circular or elliptical shapes. SLNs were studied for their effectiveness as colloidal emulsifiers in oil-in-water (o/w) emulsions. The generated o/w emulsions had a volume-weighted mean droplet size of ~459 nm by laser diffraction and ζ potential of ~-43 mV. The emulsions were stable for up to 12 wk. as observed for macroscopic changes by inverted light microscopy. TEM images pointed to the presence of a Pickering-type network stabilizing the emulsions. With time, desorption of the SLNs from the oil droplet surface into the continuous aqueous environment, coupled with Ostwald ripening, resulted in destabilization of the emulsions. Overall, these results demonstrated that stabilization of o/w emulsions was achievable using SLNs as the sole emulsifiers. Materials science ; Differential scanning calorimetry ; Particle size ; Dynamic light scattering ; Crystallization ; Zeta potential ; Contact angle ; Analytical Chemistry (journal) ; Melting point ; Solid lipid nanoparticle ; Nanoparticle ; Emulsion ; Chemical engineering ; Chromatography ; Chemistry ; Nanotechnology ; Composite material ; Thermodynamics Pickering emulsions and particle stabilization ; Food Chemistry and Fat Analysis
Authors: Benjamin Malfait | Laurent Paccou | Natália T. Correia | Yannick Guinet | Alain Hédoux
Source: Microporous and Mesoporous Materials (article, 2021-10-19)
Field: Materials Science — Materials Chemistry

Identification of an amorphous-amorphous two-step transformation in indomethacin embedded within mesoporous silica Amorphous solid ; Nanocrystal ; Materials science ; Isothermal process ; Ostwald ripening ; Mesoporous material ; Chemical engineering ; Melting point ; Nanoparticle ; Dissolution ; Chemical physics ; Nanotechnology ; Thermodynamics ; Crystallography ; Chemistry ; Organic chemistry ; Composite material ; Physics ; Catalysis Material Dynamics and Properties ; Crystallization and Solubility Studies ; Mesoporous Materials and Catalysis
Authors: Greg Bisbjerg | G. W. Brown | Kimberly S. Pham | Ryan A. de Kock | William Ramos | Jordan A. Patierno | Aleyda Bautista | Natalie M. Zawalick | Viviana Vigil | John D. Padrnos | Robert T. Mathers | Michael D. Heying | Philip R. Costanzo
Source: Journal of Polymer Science (article, 2021-10-21)
Field: Chemistry — Organic Chemistry

Exploring polymer solubility with thermally‐responsive Diels‐Alder monomers: Revisiting the monkey's fist Abstract Thermo‐responsive monomers were designed to contain a Diels‐Alder (DA) adduct such that cyclo‐reversion would yield either the maleimide or the furan unit attached to the polymer chain. These thermally responsive monomers were then copolymerized with N ‐isopropylacrylamide (NIPAM) via reversible addition‐fragmentation chain‐transfer (RAFT) polymerization to yield linear gradient‐copolymer structures as a comparison to existing nanogel/starlike systems to understand how polymer topology and composition influence solution‐state properties. Using UV–Vis spectroscopy, it was determined that solution‐state properties were thermally dependent and influenced by a number of variables such as comonomer feed ratio, polymer chain end functionality, and polymer backbone length and composition. Manipulation of the feed ratio allowed for control over the cloud point, including the breadth and location of phase separation. Thermal treatment of these copolymers revealed tunable and predictable variations in previously observed transitions, directly correlated to cleavage of the DA adducts and change in polymer backbone composition. Finally, on cooling cycles, a double sigmoid was sometimes observed, indicating a complex globule to random coil transition correlated to polymer chain end composition. These studies help understand how to untie the “monkey's fist.” Monomer ; Chain transfer ; Comonomer ; Polymer ; Polymer chemistry ; Maleimide ; Copolymer ; Raft ; Polymerization ; Methacrylate ; Materials science ; Upper critical solution temperature ; Chemistry ; Radical polymerization ; Chemical engineering ; Organic chemistry ; Lower critical solution temperature Advanced Polymer Synthesis and Characterization ; Polymer composites and self-healing