One step synthesis of tryptophan-isatin carbon nano dots and bio-applications as multifunctional nanoplatforms

The development of natural molecule-derived carbon nano dots (CNDs) marks a significant advancement in biocompatible and sustainable nanomaterials. Tryptophan, capable of crossing the blood-brain barrier (BBB), serves as a precursor to numerous pharmacologically active compounds, while isatin and its derivatives have demonstrated anti-tumor effects, including against brain cancers. This study aimed to synthesize fluorescent CNDs from tryptophan-isatin hybrid precursor and explore their applications in glioblastoma treatment. These CNDs were characterized using techniques such as TEM, SEM-EDS, FTIR, XPS, Raman spectroscopy and UV-Vis spectrophotometry. In vitro tests using the U-87 glioblastoma cell line evaluated cell viability, affinity, and BBB permeability. The CNDs, between 4 and 7 nm in size, exhibited blue and green fluorescence, with no cytotoxic effects observed at concentrations up to 25 µg/mL. The highest BBB permeability rate was determined as 4.3 × 10⁻⁵ cm/s. Additionally, the CNDs demonstrated radiotherapeutic properties, leading to a 51 % reduction in cell viability. This research contributes to nanomedicine by introducing a novel biocompatible material with potential for targeted brain cancer imaging and therapy, while also suggesting broader applications beyond glioblastoma.

In situ preparation of hetero-polymers/clay nanocomposites by CUAAC click chemistry

A series of polymer/clay nanocomposites containing mechanistically two different polymers, poly(ethylene glycol) (PEG) and poly(epsilon caprolactone) (PCL), were prepared by simultaneous copper(I)-catalyzed alkyne-azide cycloaddition click reactions. Both clickable polymers, PEG-Alkyne and PCL-Alkyne, were simultaneously clicked on to azide-functional montmorillonite (MMT-N₃) nanoclay to get corresponding PEG-PCL/MMT nanocomposites. The chemical structures of the resulting nanocomposites were verified by following azide and silicone-oxygen bands using FT-IR and characteristic bands of PEG and PCL segments using ¹H-NMR spectroscopy. The combined XRD and TEM analysis confirmed that all PEG-PCL/MMT nanocomposites had partially exfoliated/intercalated morphologies. In addition, the increase of MMT-N₃ loading not only improved the onset and maximum degradation temperatures of the nanocomposites but also their char yields. Furthermore, the incorporation of MMT-N₃ in the polymer matrix did not significantly influence the crystallization behavior of both PEG and PCL segments.

Multifunctional colloidal nanofiber composites including dextran and folic acid as electro-active platforms

This work presents the fabrication and characterization of novel colloidal multifunctional polymer nanofiber composites (NFCs) from water dispersion blends of intercalated silicate layered nanocomposites of poly (2-vinyl-N-pyrrolidone)/octadecyl amine-montmorillonite (ODA-MMT) and dextran/ODA-MMT as matrix and partner polymer intercalated nanocomposites in the presence of NaOH and folic acid (FA) as doping agents by green reactive electrospinning. Chemical and physical structures, surface morphology and electrical properties were investigated. Effects of matrix/partner polymer ratios, doping agents, absorption time of NaOH, and temperature on electrical parameters of NFCs were evaluated. The presence of FA and increasing dextran fraction in NFCs resulted in reducing fiber diameter and improving diameter distribution. High complexing behaviors of matrix/partner polymer chains, organoclay, FA, and NaOH significantly improved conductivity parameters, especially 5-min of absorption time (≈10^-2-10^-3Sm^-1). The conductivity of the samples decreased with increasing temperature. NFCs fabricated for the first time are promising candidates for various biomedical, electrochemical and electronic applications as electro-active platforms.

Polyglycolide–montmorillonite as a novel nanocomposite platform for biosensing applications

In catalytic biosensors, the immobilization of biomolecules in a suitable matrix is one of the vital parameters for obtaining improved systems.

Impregnation of zinc oxide modified clay over alginate beads: a novel material for the effective removal of congo red from wastewater

Alginate hydrogel beads were impregnated with zinc oxide (ZnO) modified sepiolite clay and applied for the removal of congo red (CR) dye from its aqueous solution in batch and packed column systems.

Non-sticky and antimicrobial zwitterionic nanocomposite dressings for infected chronic wounds

Zwitterionic poly(sulfobetaine acrylamide) (pSBAA)-based nanocomposite hydrogels can have high potential for the treatment of infected chronic wounds.

Folic acid conjugated and Ag-carrying organoclay nanoparticles and their response to L929 fibroblast and DLD-1 cancer cells

This work presents the synthesis and characterisation of intercalated nanocomposites (NCs) from dispersed water solution blends of octadecyl amine-montmorillonite (ODA-MMT) (NC-0), folic acid (FA) conjugated ODA-MMT (NC-1) and Ag-MMT clay as a stable silver carrying agent (NC-2). The composition, chemical/physical and morphology of NCs with in situ intercalating nanostructures were investigated. Effect of organoclay, FA and Ag-MMT on L929 fibroblast (control), human colon carcinoma (DLD-1) cell lines, and the cytotoxicity, apoptosis and necrosis degree were estimated via WST-1/hemocytometric, double staining (as a ribonuclease A enzyme based method) and fluorescence microscopy methods in a dose-dependent manner. The mentioned cell lines integrated with NCs resulted in remarkable change in both morphology and nuclei of DLD-1 and fibroblast cells by apoptosis analysis. The number of necrotic cells were remarkably increased, as the toxic effects of nanocomposite nanoparticles were applied to both cell lines. Finally, the molecular mechanism of anticancer action of functionalised organoclays was elucidated.

Towards the electrochemical diagnosis of cancer: nanomaterial-based immunosensors and cytosensors

In this review, nanomaterial based electrochemical biosensors including electrochemical immunosensors and cytosensors towards cancer detection are covered.

Bi-axially oriented polystyrene/montmorillonite nanocomposite films

Polystyrene (PS)/montmorillonite (MMT) nanocomposite films were prepared by bi-axially stretching compounded and extruded PS/MMT nanocomposite sheets, resulting in an improved level of exfoliation and orientation during stretching.