Do microplastics accumulate in penguin internal organs? Evidence from Svenner island, Antarctica.

The prevalence of microplastics (MPs, <5 mm) in natural environments presents a formidable global environmental threat MPs can be found from the Arctic to Antarctica, including glaciers. Despite their widespread distribution, studies on MP accumulation in apex predators inhabiting Polar Regions remain limited. The objective of this study was to conduct a comprehensive examination, for the first time, of MP bioaccumulation in various organs and tissue of Adélie penguins.

Developing Supramolecular Metallogel Derived from PdL Cage Molecule for Delivering an Anti-Cancer Drug to Melanoma Cell B16-F10.

Supramolecular gels are an important class of materials that are promising for its wide range of applications including drug delivery. While supramolecular gels are intrinsically porous because of the 3D nano-matrix (gel matrix) that is being formed due to supramolecular self-assembly process involving the gelator molecules during gelation, additional nanopores can be introduced to the overall gel if the gelator molecule itself holds molecular cavity such as metal-organic-cage (MOC) molecules. A MOC having the molecular formula [(PdL2).

Impact of calcium hydroxide and 2-hydroxyisocaproic acid on the microhardness of root dentine: an in vitro study.

To evaluate and compare the effect of calcium hydroxide [Ca(OH)] and 2-hydroxyisocaproic acid (HICA) on the microhardness of root dentine. Fifty-one matured maxillary central incisors with straight root and type I canal configuration were decoronated to a standardized length of 16 mm. The root canals were cleaned and shaped using rotary instruments up to size F5.

Antibacterial Hydrogel as a Self-Drug-Delivery System Derived from Zn(II)-bis-imidazole/NSAID-Based Organic-Inorganic Hybrids.

A skin wound is prone to bacterial infection and growth. An antibacterial topical hydrogel that can act as a self-drug-delivery (SDD) system is reported here. Two bidentate ligands () derived from imidazole/benzimidazole derivatives when reacted with Zn(NO) and a series of nonsteroidal-anti-inflammatory drugs (NSAIDs) produced crystalline products, which were characterized by single-crystal X-ray diffraction (SXRD).

Designing a vehicle-free anti-bacterial topical hydrogel from Fmoc-diphenylalanine.

A supramolecular synthon-based salt formation strategy has been employed to afford an anti-bacterial topical hydrogel from Fmoc-diphenylalanine (FmocFF). The nontrivial steps (pH/solvent switch along with heat-cool protocol) required for making the hydrogel from FmocFF were successfully avoided following this strategy.

An injectable supramolecular hydrogel as a self-drug-delivery system for local chemoimmunotherapy against melanoma.

Skin-cancer melanoma caused 57k death in 2020. Some of the available therapies are: topical application of a gel loaded with an anti-skin cancer drug and intravenous injection of immune cytokines; however, both the approaches have drawbacks such as inefficient internalization of the drug in cancer cells and a short half-life with severe side effects, respectively. Interestingly, we observed for the first time that a subcutaneously implanted hydrogel designed and synthesized by coordinating NSAIDs and 5-AP with Zn(II) can effectively combat melanoma cell (B16-F10)-induced tumors in C57BL/6 mice.

Real-time Observation of Macroscopic Helical Morphologies under Optical Microscope: A Curious Case of π-π Stacking Driven Molecular Self-assembly of an Organic Gelator Devoid of Hydrogen Bonding.

Supramolecular assemblies such as tubules/helix/double helix/helical tape etc. are usually submicron objects preventing direct observation under optical microscope. Chiral-pure form of these assemblies is important for potential applications.

Selective Separation of Hazardous Chemicals from Vapor Phase by an Easily Accessible Breathing Coordination Polymer Derived from Terpyridyl/terephthalate Mixed Ligands.

Coordination polymers are extensively studied materials because of their various potential applications. Amongst them, breathing coordination polymers that are capable of exchanging lattice occluded guest molecules with other guests via single-crystal-to-single-crystal (SC-SC) fashion are particularly intriguing. Herein, we disclose an easily accessible breathing coordination polymer namely DMF@Zn-CP capable of exchanging as many as 23 guest molecules of various kinds in SC-SC fashion when the crystals of the coordination polymer were exposed to the corresponding vapor of the guests.

Designing coordination polymers as multi-drug-self-delivery systems for tuberculosis and cancer therapy: viability and toxicity assessment.

A proof of concept for designing multi-drug-delivery systems suitable for self-drug-delivery is disclosed. Simple coordination chemistry was employed to anchor two kinds of drugs namely isoniazid (IZ - anti-tuberculosis), various non-steroidal-anti-inflammatory-drugs (NSAIDs) namely ibuprofen-IBU, fenoprofen-FEN, naproxen-NAP, diclofenac-DIC and mefenamic acid-MEF and Zn(NO) to synthesize a series of 1D coordination polymers namely IZIBU, IZFEN, IZNAP, IZDIC and IZMEF which were structurally characterized by single crystal X-ray diffraction (SXRD). The coordination polymers wherein both types of drugs were anchored to Zn(II) metal centers could easily be ground to nano-sized particles suitable for biological studies by hand grinding in a mortar and pestle.

Supramolecular Gels from Bis-amides of L-Phenylalanine: Synthesis, Structure and Material Applications.

A series of small organic molecules having a bis-amide backbone containing hydrogen-bond functionalities were rationally designed, synthesized and characterized to examine their ability to act as potential low-molecular-weight gelators (LMWGs). All the bis-amides were decorated with identical 3-pyridyl amide of L-phenylalanine moieties along with variously substituted terminal benzoyl groups. Gelation studies revealed that only 4-methylphenyl substituted bis-amide (PME) was capable of gelling both aqueous (DMSO/water) and methyl salicylate (MS) (an important solvent for topical formulation for medical applications) solvents; whereas 4-chlorophenyl and 4-bromophenyl substituted bis-amides (PCL, PBR, respectively) acted as organogelator for various organic solvents.

Nitrile-Containing Terpyridyl Zn(II)-Coordination Polymer-Based Metallogelators Displaying Helical Structures: Synthesis, Structures, and "Druglike" Action against B16-F10 Melanoma Cells.

An attempt has been made to develop a self-drug-delivery system against melanoma from a series of metallogelators derived from coordination polymers. Thus, a series of coordination polymers (-) derived from a nitrile-containing terpyridyl ligand () and transition metal salts (Cu(I)/Zn(II)) have been synthesized and thoroughly characterized by a number of physicochemical techniques including single crystal X-ray diffraction. Reactions of the ingredients of the coordination polymers guided by their single crystal structures produced four metallogels (-) which were characterized by dynamic rheology and TEM.

Supramolecular Hydrogels Developed from Mafenide and Indomethacin as a Plausible Multidrug Self-Delivery System as Antibacterial and Anti-inflammatory Topical Gels.

Following a structural rationale, a series of simple organic salts derived from mafenide (a drug for treating burn wounds) and -alkyl carboxylic acids (Me-(CH)-COOH; = 1-3, 10-15) and various nonsteroidal anti-inflammatory drugs (NSAIDs), namely, indomethacin (, diclofenac (, meclofenamic acid (), tolfenamic acid (), and flufenamic acid () (designated as salts , respectively) were synthesized as potential hydrogelators. Gelation studies revealed that mafenide -alkyl carboxylates with = 11-14, i.e.

Multi-NSAID-based Zn(II) coordination complex-derived metallogelators/metallogels as plausible multi-drug self-delivery systems.

Metallogelators/metallogels derived from a series of multi-NSAID-based Zn(II)-coordination complexes displaying anti-cancer and anti-bacterial properties were designed based on a structural rationale as plausible multi-drug self-delivery systems.

Anchoring Drugs to a Zinc(II) Coordination Polymer Network: Exploiting Structural Rationale toward the Design of Metallogels for Drug-Delivery Applications.

A new series of coordination polymers (CPs) were synthesized and crystallographically characterized by single-crystal X-ray diffraction with the aim of developing drug-delivery systems via metallogel formation. Structural rationale was employed to design such coordination-polymer-based metallogels. As many as nine CPs were obtained by reacting two bis(pyridyl)urea ligands, namely, 1,3-dipyridin-3-ylurea () and 1,3-dipyridin-4-ylurea (), and the sodium salt of various nonsteroidal antiinflammatory drugs, namely, ibuprofen (), naproxen (), fenoprofen (), diclofenac (), meclofenamic acid (), mefenamic acid (), and Zn(NO).

Designing Metallogelators Derived from NSAID-based Zn(II) Coordination Complexes for Drug-Delivery Applications.

A crystal engineering approach has been invoked to design a new series of eight Zn(II) coordination complexes derived from various non-steroidal anti-inflammatory drugs (NSAIDs), namely diclofenac (DIC), ibuprofen (IBU), naproxen (NAP), flufenamic acid (FLU) and meclofenamic acid (MEC), and two co-ligands, namely N-phenyl-3-pyridylamide (3-Py) and N-phenyl-4-pyridylamide (4-Py), and Zn(NO ) as potential supramolecular gelators. Half of the coordination complexes thus synthesized were able to form aqueous gels (MG-3-PyMEC, MG-3-PyDIC, MG-4-PyNAP and MG-4-PyMEC). Single-crystal structures of all eight complexes revealed that they possessed a gelation-inducing 1D hydrogen-bonded network including amide…amide synthon in some cases, which supported strongly the design principles based on which these complexes were synthesized.

A supramolecular hydrogel derived from a simple organic salt capable of proton conduction.

The supramolecular hydrogel of a simple organic salt derived from a primary amine and a mono-sulfonic acid displayed a proton conductivity of 1.2 × 10 S cm. The hitherto unknown example of the supramolecular gel displaying proton conductivity provides an intriguing alternative to liquid electrolyte or polymer gel electrolytes.

Cu(II)-Metallacryptands Self-Assembled to Vesicular Aggregates Capable of Encapsulating and Transporting an Anticancer Drug Inside Cancer Cells.

Crystallographically characterized M L type cationic Cu(II)-metallacryptands [MC(X)] derived from a series of bis-pyridyl-bis-urea ligands (L ; X = O, S, C) are self-assembled to single-layered vesicular aggregates in DMSO, DMSO/water, and DMSO/DMEM (biological media). One such vesicle is MC(O)-vesicle that is demonstrated to be able to load and release (pH responsive) an anticancer drug, namely doxorubicin hydrochloride (DOX). DOX-loaded MC(O)-vesicle is also successfully transported within MDA-MB-231 cells-a highly aggressive human breast cancer cell line.

Design and Synthesis of Zn -Coordination Polymers Anchored with NSAIDs: Metallovesicle Formation and Multi-drug Delivery.

A series of coordination polymers synthesized from a bis-pyridyl linker, namely 4,4'-azopyridine (L), selected non-steroidal-anti-inflammatory drugs (NSAIDs), namely diclofenac (Dic), ibuprofen (Ibu), flurbiprofen (Flu), mefenamic acid (Mefe), and naproxen (Nap), and Zn(NO ) were characterized by single crystal X-ray diffraction. One of the coordination polymers, namely CP3 derived from Flu, was able to form metallovesicles in DMSO, DMSO/H O and DMSO/DMEM (biological media) as revealed by TEM, AFM and DLS. Metallovesicle formation by CP3 was further supported by loading a fluorescent dye, namely calcein, as well as an anti-cancer drug, doxorubicin hydrochloride (DOX), as revealed by UV-vis and emission spectra, and fluorescence microscopy.

An easy access to topical gels of an anti-cancer prodrug (5-fluorouracil acetic acid) for self-drug-delivery applications.

An easy access to topical gels (both hydro- and organogels) derived from an anti-cancer prodrug namely 5-fluorouracil acetic acid (5-FuA) achieved by exploiting a simple salt formation strategy is reported for the first time. Nearly 85% of the salts synthesized were gelators. Single crystal structures of some of the gelator salts revealed an intriguing hydrogen bonding network including double stranded 1D chains stabilized through uracil-uracil complementary interactions and the crystal structures of the gelator salts corroborated well with the hypothesis based on which the gelators were designed.

Supramolecular Gels Derived from Simple Organic Salts of Flufenamic Acid: Design, Synthesis, Structures, and Plausible Biomedical Application.

Following supramolecular synthon rationale in the context of crystal engineering, a nonsteroidal-anti-inflammatory-drug (NSAID), namely flufenamic acid () and its β-alanine monopeptide derivative (), were converted to a series of primary ammonium monocarboxylate (PAM) salts. Majority of the PAM salts (∼90%) showed gelation with various solvents including water and methyl salicylate (important solvents in topical gel formulation). Structure-property correlation studies based on single-crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) data provided intriguing insights into the structure of the gel network.

Self-Assembly of Spherical Organic Molecules to Form Hollow Vesicular Structures in Water for Encapsulation of an Anticancer Drug and Its Release.

Developing hierarchical supramolecular structures is important for better understanding of various biological functions and possibly generating new materials for biomedical applications. Herein, we report the first examples of functional vesicles derived from cationic spherical organic molecules (C -C ) which were readily synthesized by reacting a C -symmetric tris-benzimmidazole derivative (possessing a 1,3,5-ethyl substituted aromatic core) with 1,3,5-substituted tris-bromomethyl benzene derivatives. Vesicle formation by C -C was probed by high-resolution microscopy (TEM and AFM), dynamic light scattering (DLS) and fluorescence microscopic imaging of calcein-loaded vesicles.

Designing Supramolecular Gelators: Challenges, Frustrations, and Hopes.

This article is a personal account of the author, who serendipitously entered the field of supramolecular gels nearly two decades ago. A supramolecular synthon approach in the context of crystal engineering was utilized to develop a working hypothesis to design supramolecular gelators derived from simple organic salts. The activity not only provided a way to occasionally predict gelation, but also afforded clear understanding of the structural landscape of such supramolecular materials.

Diffusion tensor imaging and disability progression in multiple sclerosis: A 4-year follow-up study.

Objectives: Diffusion tensor imaging (DTI) is sensitive technique to detect widespread changes in water diffusivity in the normal-appearing white matter (NAWM) that appears unaffected in conventional magnetic resonance imaging. We aimed to investigate the prognostic value and stability of DTI indices in the NAWM of the brain in an assessment of disability progression in patients with a relapsing-onset multiple sclerosis (MS).

Methods: Forty-six MS patients were studied for DTI indices (fractional anisotropy (FA), mean diffusivity (MD), radial (RD), and axial (AD) diffusivity) in the NAWM of the corpus callosum (CC) and the internal capsule at baseline and at 1 year after.