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.

Pathogenic bacteria have the ability to develop antibiotic resistance mechanisms. Their action consists mainly in the production of bacterial enzymes that inactivate antibiotics or the appearance of modifications that prevent the arrival of the drug at the target point or the alteration of the target point itself, becoming a growing problem for health systems. Chitosan–gold nanoparticles (Cs-AuNPs) have been shown as effective bactericidal materials avoiding damage to human cells. In this work, Cs-AuNPs were synthesized using chitosan as the reducing agent, and a systematic analysis of the influence of the synthesis parameters on the size and zeta potential of the Cs-AuNPs and their UV-vis spectra was carried out. We used a simulation model to characterize the interaction of chitosan with bacterial membranes, using a symmetric charged bilayer and two different chitosan models with different degrees of the chitosan amine protonation as a function of pH, with the aim to elucidate the antibacterial mechanism involving the cell wall disruption. The Cs-AuNP antibacterial activity was evaluated to check the simulation model.

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.

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.

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.