Folic Acid-Decorated Nanocrystals as Highly Loaded Trojan Horses to Target Cancer Cells.

The nanocrystal (NC) technology has become one of the most commonly used strategies for the formulation of poorly soluble actives. Given their large specific surface, NCs are mainly used to enhance the oral absorption of poorly soluble actives. Differently from conventional nanoparticles, which require the use of carrier materials and have limited drug loadings, NCs' drug loading approaches 100% since they are formed of the pure drug and surrounded by a thin layer of a stabilizer. In this work, we report the covalent decoration of curcumin NCs with folic acid (FA) using EDC/NHS chemistry and explore the novel systems as highly loaded "Trojan horses" to target cancer cells. The decorated NCs demonstrated a remarkable improvement in curcumin uptake, exhibiting enhanced growth inhibition in cancer cells (HeLa and MCF7) while sparing healthy cells (J774A.1). Cellular uptake studies revealed significantly heightened entry of FA-decorated NCs into cancer cells compared to unmodified NCs while also showing reduced uptake by macrophages, indicating a potential for prolonged circulation in vivo. These findings underline the potential of NC highly loaded nanovectors for drug delivery and, in particular, for cancer therapies, effectively targeting folate receptor-overexpressing cells while evading interception by macrophages, thus preserving their viability and offering a promising avenue for precise and effective treatments.

Synthesis and Characterization of New Ruthenium (II) Complexes of Stoichiometry [Ru(p-Cymene)Cl2L] and Their Cytotoxicity against HeLa-Type Cancer Cells.

When the [Ru(p-cymene)(µ-Cl)Cl]2 complex is made to react, in dichloromethane, with the following ligands: 2-aminobenzonitrile (2abn), 4-aminobenzonitrile (4abn), 2-aminopyridine (2ampy) and 4-aminopyridine (4ampy), after addition of hexane, the following compounds are obtained: [Ru(p-cymene)Cl2(2abn)] (I), [Ru(p-cymene)Cl2(4abn)] (II), [Ru(p-cymene)Cl2(2ampy] (III) and [Ru(p-cymene)Cl2(µ-(4ampy)] (IV). All the compounds are characterized by elemental analysis of carbon, hydrogen and nitrogen, proton nuclear magnetic resonance, COSY 1H-1H, high-resolution mass spectrometry (ESI), thermogravimetry and single-crystal X-ray diffraction (the crystal structure of III is reported and compared with the closely related literature of II). The cytotoxicity effects of complexes were described for cervical cancer HeLa cells via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay. The results demonstrate a low in vitro anticancer potential of the complexes.

p-Cymene Complexes of Ruthenium(II) as Antitumor Agents.

In this work, the cytotoxic behavior of six ruthenium(II) complexes of stoichiometry [(η6-p-cymene)RuCl2L] (I-VI), L = 4-cyanopyridine (I), 2-aminophenol (II), 4-aminophenol (III), pyridazine (IV), and [(η6-p-cymene)RuClL2]PF6; L = cyanopyridine (V), L = 2-aminophenol(VI) towards three cell lines was studied. Two of them, HeLa and MCF-7, are human carcinogenic cells from cervical carcinoma and human breast cancer, respectively. A comparison with healthy cells was carried out with BGM cells which are monkey epithelial cells of renal origin. The behavior of complex II exhibits selectivity towards healthy cells, which is a promising feature for use in cancer treatment since it might reduce the side effects of most current therapies.

Synthesis of Cellulose Nanoparticles from Ionic Liquid Solutions for Biomedical Applications.

A method for the synthesis of cellulose nanoparticles using the ionic liquid 1-ethyl-3-methylimidazolium acetate has been optimised. The use of a highly biocompatible biopolymer such as cellulose, together with the use of an ionic liquid, makes this method a promising way to obtain nanoparticles with good capability for drug carrying. The operating conditions of the synthesis have been optimised based on the average hydrodynamic diameter, the polydispersity index, determined by Dynamic Light Scattering (DLS) and the Z-potential, obtained by phase analysis light scattering (PALS), to obtain cellulose nanoparticles suitable for use in biomedicine. The obtained cellulose nanoparticles have been characterised by Fourier transform infrared spectroscopy (FTIR) with attenuated total reflectance (ATR), field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA/DTA). Finally, cell viability studies have been performed with a cancer cell line (HeLa) and with a healthy cell line (EA.hy926). These have shown that the cellulose nanoparticles obtained are not cytotoxic in the concentration range of the studied nanoparticles. The results obtained in this work constitute a starting point for future studies on the use of cellulose nanoparticles, synthesised from ionic liquids, for biomedical applications such as targeted drug release or controlled drug release.

Folic Acid-Modified Ibrutinib-Loaded Silk Fibroin Nanoparticles for Cancer Cell Therapy with Over-Expressed Folate Receptor.

The anticancer drug ibrutinib (IB), also known as PCI-32765, is a compound that irreversibly inhibits Bruton's tyrosine kinase (BTK) and was initially developed as a treatment option for B-cell lineage neoplasms. Its action is not limited to B-cells, as it is expressed in all hematopoietic lineages and plays a crucial role in the tumor microenvironment. However, clinical trials with the drug have resulted in conflicting outcomes against solid tumors. In this study, folic acid-conjugated silk nanoparticles were used for the targeted delivery of IB to the cancer cell lines HeLa, BT-474, and SKBR3 by exploiting the overexpression of folate receptors on their surfaces. The results were compared with those of control healthy cells (EA.hy926). Cellular uptake studies confirmed total internalization of the nanoparticles functionalized by this procedure in the cancer cells after 24 h, compared to nanoparticles not functionalized with folic acid, suggesting that cellular uptake was mediated by folate receptors overexpressed in the cancer cells. The results indicate that the developed nanocarrier can be used for drug targeting applications by enhancing IB uptake in cancer cells with folate receptor overexpression.

Accelerated Simple Preparation of Curcumin-Loaded Silk Fibroin/Hyaluronic Acid Hydrogels for Biomedical Applications.

The development of new biomaterials from natural fibres in the field of biomedicine have attracted great interest in recent years. One of the most studied fibres has been silk fibroin produced by the Bombyx mori worm, due to its excellent mechanical properties and its biodegradability and bioavailability. Among the different biomaterials that can be prepared from silk fibroin, hydrogels have attracted considerable attention due to their potential use in different fields, such as scaffolding, cell therapy and biomedical application. Hydrogels are essentially a three-dimensional network of flexible polymer chains that absorb considerable amounts of water and can be loaded with drugs and/or cells inside to be used in a wide variety of applications. Here we present a simple sonication process for the preparation of curcumin-hyaluronic acid-silk fibroin hydrogels. Different grades of hydrogels were prepared by controlling the relative amounts of their components. The hydrogels were physically and morphologically characterised by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM) and their biological activity was tested in terms of cell viability in a fibroblast cell line.

The Effect of Sterilization on the Characteristics of Silk Fibroin Nanoparticles.

In recent years, silk fibroin nanoparticles (SFNs) have been consolidated as drug delivery systems (DDSs) with multiple applications in personalized medicine. The design of a simple, inexpensive, and scalable preparation method is an objective pursued by many research groups. When the objective is to produce nanoparticles suitable for biomedical uses, their sterility is essential. To achieve sufficient control of all the crucial stages in the process and knowledge of their implications for the final characteristics of the nanoparticles, the present work focused on the final stage of sterilization. In this work, the sterilization of SFNs was studied by comparing the effect of different available treatments on the characteristics of the nanoparticles. Two different sterilization methods, gamma irradiation and autoclaving, were tested, and optimal conditions were identified to achieve the sterilization of SFNs by gamma irradiation. The minimum irradiation dose to achieve sterilization of the nanoparticle suspension without changes in the nanoparticle size, polydispersity, or Z-potential was determined to be 5 kiloGrays (kGy). These simple and safe methods were successfully implemented for the sterilization of SFNs in aqueous suspension and facilitate the application of these nanoparticles in medicine.

Antitumor Activity of Rosmarinic Acid-Loaded Silk Fibroin Nanoparticles on HeLa and MCF-7 Cells.

Rosmarinic acid (RA), one of the most important polyphenol-based antioxidants, has drawn increasing attention because of its remarkable bioactive properties, including anti-inflammatory, anticancer and antibacterial activities. The aim of this study was to synthesize and characterize RA-loaded silk fibroin nanoparticles (RA-SFNs) in terms of their physical-chemical features and composition, and to investigate their antitumor activity against human cervical carcinoma and breast cancer cell lines (HeLa and MCF-7). Compared with the free form, RA bioavailability was enhanced when the drug was adsorbed onto the surface of the silk fibroin nanoparticles (SFNs). The resulting particle diameter was 255 nm, with a polydispersity index of 0.187, and the Z-potential was -17 mV. The drug loading content of the RA-SFNs was 9.4 wt.%. Evaluation of the in vitro drug release of RA from RA-SFNs pointed to a rapid release in physiological conditions (50% of the total drug content was released in 0.5 h). Unloaded SFNs exhibited good biocompatibility, with no significant cytotoxicity observed during the first 48 h against HeLa and MCF-7 cancer cells. In contrast, cell death increased in a concentration-dependent manner after treatment with RA-SFNs, reaching an IC50 value of 1.568 and 1.377 mg/mL on HeLa and MCF-7, respectively. For both cell lines, the IC50 of free RA was higher. The cellular uptake of the nanoparticles studied was increased when RA was loaded on them. The cell cycle and apoptosis studies revealed that RA-SFNs inhibit cell proliferation and induce apoptosis on HeLa and MCF-7 cell lines. It is concluded, therefore, that the RA delivery platform based on SFNs improves the antitumor potential of RA in the case of the above cancers.

Improving Anticancer Therapy with Naringenin-Loaded Silk Fibroin Nanoparticles.

Naringenin (NAR), a flavonoid present in a variety of fruits, vegetables and herbs, exhibits a wide range of pharmacological effects, including anticancer activity. Nevertheless, its application in cancer therapy is limited due to its low bioavailability at the tumour site because of its poor solubility in water and slow dissolution rate. To improve the therapeutic efficacy of NAR, emergent research is looking into using nanocarriers. Silk fibroin (SF), from the Bombyx mori silkworm, is a biocompatible and biodegradable polymer with excellent mechanical properties and an amphiphilic chemistry that make it a promising candidate as a controlled release drug system. The aim of this work is to synthesize naringenin-loaded silk fibroin nanoparticles (NAR-SFNs) by dissolving the SF in the ionic liquid 1-ethyl-3-methylimidazolium acetate, using high-power ultrasounds and rapid desolvation in methanol followed by the adsorption of NAR. The NAR-SFNs were characterized by dynamic light scattering, Fourier transform infrared spectroscopy and thermogravimetric analysis. The drug loading content and encapsulation efficiency were calculated. The drug release profile best fitted a first order equation. The cytotoxicity effects of free NAR, bare silk fibroin nanoparticles (SFNs) and NAR-SFNs were assessed on HeLa and EA.hy926 cells via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results demonstrated the higher in vitro anticancer potential of synthesized NAR-SFNs than that of free NAR in HeLa cancer cells.