Novel morphology change of Au-Methotrexate conjugates: From nanochains to discrete nanoparticles

Multi-shell gold nanoparticles functionalized with methotrexate: a novel nanotherapeutic approach for improved antitumoral and antioxidant activity and enhanced biocompatibility

Methotrexate (MTX) is a folic acid antagonist routinely used in cancer treatment, characterized by poor water solubility and low skin permeability. These issues could be mitigated by using drug delivery systems, such as functionalized gold nanoparticles (AuNPs), known for their versatility and unique properties. This study aimed to develop multi-shell AuNPs functionalized with MTX for the improvement of MTX antitumoral, antioxidant, and biocompatibility features. Stable phosphine-coated AuNPs were synthesized and functionalized with tailored polyethylene glycol (PEG) and short-branched polyethyleneimine (PEI) moieties, followed by MTX covalent binding. Physicochemical characterization by UV-vis and Fourier-transform infrared spectroscopy (FTIR) spectroscopy, dynamic light scattering (DLS), scanning transmission electron microscopy (STEM), and X-ray photoelectron spectroscopy (XPS) confirmed the synthesis at each step. The antioxidant activity of functionalized AuNPs was determined using DPPH radical scavenging assay, ferric ions' reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. Biocompatibility and cytotoxicity were assessed using MTT and LDH assays on HaCaT human keratinocytes and CAL27 squamous cell carcinoma. MTX functionalized AuNPs demonstrated enhanced antioxidant activity and a pronounced cytotoxic effect on the tumoral cells compared to their individual components, highlighting their potential for improving cancer therapy.

Methotrexate Gold Nanocarriers: Loading and Release Study: Its Activity in Colon and Lung Cancer Cells

In the present study, the synthesis of gold nanoparticles (AuNPs) loaded with methotrexate (MTX) has been carried out in order to obtain controlled size and monodispersed nanocarriers of around 20 nm. The characterization study shows metallic AuNPs with MTX polydispersed on the surface. MTX is linked by the replacement of citrate by the MTX carboxyl group. The drug release profiles show faster MTX release when it is conjugated, which leads to the best control of plasma concentration. Moreover, the enhanced release observed at pH 5 could take advantage of the pH gradients that exist in tumor microenvironments to achieve high local drug concentrations. AuNP–MTX conjugates were tested by flow cytometry against lung (A-549) and colon (HTC-116) cancer cell lines. Results for A-549 showed a weaker dose–response effect than for colon cancer ones. This could be related to the presence of folate receptors in line HTC-116 in comparison to line A-549, supporting the specific uptake of folate-conjugated AuNP–MTX by folate receptor positive tumor cells. Conjugates exhibited considerably higher cytotoxic effects compared with the effects of equal doses of free MTX. Annexin V-PI tests sustained the cell death mechanism of apoptosis, which is normally disabled in cancer cells.

Folic Acid/Methotrexate Functionalized Mesoporous Silica Nanoflakes from Different Supports: Comparative Study

Herein, we present a facile synthesis route for the mesoporous silica nanoflakes on two types of templates and evaluate their potential as potential drug delivery systems. Silica materials are attractive due to their biocompatibility, low cytotoxicity, high surface area, and tunable pores. In addition, they can be multifunctionalized. These properties were used to create multifunctional drug delivery systems combining folic acid as a target molecule and methotrexate (MTX) as an anticancer drug. The silica nanoflakes were formed using graphene oxide and double-layered hydroxide as templates, respectively. After the removal of matrices, the silica flakes were functionalized by folic acid and loaded with methotrexate. The differences in drug release performance and structural stability were analyzed with respect to the detailed physicochemical characterization of the produced silica nanoflakes.

Photothermally Controlled Methotrexate Release System Using β-Cyclodextrin and Gold Nanoparticles

The inclusion compound (IC) of cyclodextrin (CD) containing the antitumor drug Methotrexate (MTX) as a guest molecule was obtained to increase the solubility of MTX and decrease its inherent toxic effects in nonspecific cells. The IC was conjugated with gold nanoparticles (AuNPs), obtained by a chemical method, creating a ternary intelligent delivery system for MTX molecules, based on the plasmonic properties of the AuNPs. Irradiation of the ternary system, with a laser wavelength tunable with the corresponding surface plasmon of AuNPs, causes local energy dissipation, producing the controlled release of the guest from CD cavities. Finally, cell viability was evaluated using MTS assays for β-CD/MTX and AuNPs + β-CD/MTX samples, with and without irradiation, against HeLa tumor cells. The irradiated sample of the ternary system AuNPs + β-CD/MTX produced a diminution in cell viability attributed to the photothermal release of MTX.

Induction of Au-methotrexate conjugates by sugar molecules: production, assembly mechanism, and bioassay studies

Au-methotrexate (Au-MTX) conjugates induced by sugar molecules were produced by a simple, one-pot, hydrothermal growth method. Herein, the Au(III)-MTX complexes were used as the precursors to form Au-MTX conjugates. Addition of different types of sugar molecules with abundant hydroxyl groups resulted in the formation of Au-MTX conjugates featuring distinct characteristics that could be explained by the diverse capping mechanisms of sugar molecules. That is, the instant-capping mechanism of glucose favored the generation of peanut-like Au-MTX conjugates with high colloidal stability while the post-capping mechanism of dextran and sucrose resulted in the production of Au-MTX conjugates featuring excellent near-infrared (NIR) optical properties with a long-wavelength plasmon resonance near 630-760 nm. Moreover, in vitro bioassays showed that cancer cell viabilities upon incubation with free MTX, Au-MTX conjugates doped with glucose, dextran and sucrose for 48 h were 74.6%, 55.0%, 62.0%, and 63.1%, respectively. Glucose-doped Au-MTX conjugates exhibited a higher anticancer activity than those doped with dextran and sucrose, therefore potentially presenting a promising treatment platform for anticancer therapy. Based on the present study, this work may provide the first example of using biocompatible sugars as regulating agents to effectively guide the shape and assembly behavior of Au-MTX conjugates. Potentially, the synergistic strategy of drug molecules and sugar molecules may offer the possibility to create more gold-based nanocarriers with new shapes and beneficial features for advanced anticancer therapy.

Effect of in situ modification of bacterial cellulose with carboxymethylcellulose on its nano/microstructure and methotrexate release properties

Bacterial cellulose/carboxymethylcelullose (BC/CMC) biocomposites with different DS-CMC (DS from 0.7 to 1.2) were developed in order to evaluate their impact as a drug delivery system. Biocomposites were loaded with methotrexate (MTX) as an alternative for the topical treatment of psoriasis. Scanning electron microscopy and atomic force microscopy showed that the CMC coated the cellulose nanofibers, leading to the decrease of the elastic modulus as the DS of CMC increased. BC/CMC0.9 exhibited the lower liquid uptake (up to 11 times lower), suggesting that the more linear structure of the intermediate substitute CMC grade (0.9) was able to interact more strongly with BC, resulting in a denser structure. All samples showed a typical burst release effect in the first 15min of test, however the BC/CMC0.9 biocomposite promoted a slight lowering of MTX release rates, suggesting that the DS of CMC can be considered the key factor to modulate the BC properties.