Preparation and functionalization of cellulose nanofibers using a naturally occurring acid and their application in stabilizing linseed oil/water Pickering emulsions.

Finding efficient and environmental-friendly methods to produce and chemically modify cellulose nanofibers (CNFs) remains a challenge. In this study, lactic acid (LA) treatment followed by microfluidization was employed for the isolation and functionalization of CNFs. Small amounts of HCl (0.01, 0.1, and 0.2 M) were used alongside LA to intensify cellulose hydrolysis. FTIR spectroscopy and solid-state 13C NMR confirmed the successful functionalization of CNFs with lactyl groups during isolation, while SEM, AFM, and rheological tests revealed that the addition of HCl governed the fibers' sizes and morphology. Notably, the treatment with LA and 0.2 M HCl resulted in a more efficient defibrillation, yielding smaller nanofibers sizes (62 nm) as compared to the treatment with LA or HCl alone (90 and 108 nm, respectively). The aqueous suspension of CNFs treated with LA and 0.2 M HCl showed the highest viscosity and storage modulus. LA-modified CNFs were tested as stabilizers for linseed oil/water (50/50 v/v) emulsions. Owing to the lactyl groups grafted on their surface and higher aspect ratio, CNFs produced with 0.1 and 0.2 M HCl led to emulsions with increased stability (a creaming index increase of only 3 % and 1 %, respectively, in 30 days) and smaller droplets sizes of 23.4 ± 1.2 and 35.5 ± 0.5 µm, respectively. The results showed that LA-modified CNFs are promising stabilizers for Pickering emulsions.

Polydopamine conjugated SiO2 nanoparticles as potential drug carriers for melanoma treatment.

Silica nanoparticles (SiO2) are increasingly investigated for biomedical applications. Aim: This study aimed to analyze the potential use of a SiO2 nanoparticles coated with biocompatible polydopamine (SiO2@PDA) as a potential chemotherapeutic drug carrier. Materials & methods: SiO2 morphology and PDA adhesion was analyzed by dynamic light scattering, electron microscopy and nuclear magnetic resonance. Cytotoxicity studies and morphology analyses (immunofluorescence, scanning and transmission electron microscopy) were used to assess the cellular reaction to the SiO2@PDA nanoparticles and to identify a biocompatible (safe use) window. Results & conclusion: Concentrations above 10 µg/ml and up to 100 µg/ml SiO2@PDA showed the best biocompatibility on human melanoma cells at 24 h and represent a potential drug carrier template for targeted melanoma cancer treatment.

Tiny particles can be small enough to enter cells. This is why they may be useful in the treatment of cancer. We made particles in a way that is friendly for human cells, then we analyzed their effects on cancer cells. Our tests showed that these particles could be useful for treatment because they do not worsen cancer cells. This is important because sometimes after treatment, cancer cells can become more dangerous. This way, even if the drug did not work, the cancer will not worsen.

Highly sensitive solid forms discrimination on the whole tablet of the active ingredients in quercetin dietary supplements by NMR crystallography approaches.

Similarly to synthetic drugs, the exact crystalline form of active ingredients in solid formulations of dietary supplements may directly influence the dissolution rate, bioavailability, and stability of the final product, but this information is usually not provided by manufacturers. Working on the examples of two commercial quercetin dietary supplements a quick, reliable, and sensitive method is introduced for quercetin solid forms discrimination directly on the marketed products, without the need for prior sample preparation. It exploits the complementarity between solid-state Nuclear Magnetic Resonance (ss-NMR) and Powder X-Ray Diffraction (PXRD), which proved essential for performing a complete and accurate solid-state characterization of the two commercial products, and for obtaining new insights into the complex quercetin solid-forms landscape. The method can be readily generalized also to other dietary supplements based on bio-flavonoids/polyphenols.