Cellulose nanocrystals (CNC) receive great attention for their physical and optical properties, high surface area, high tensile strength, rigidity (Young’s modulus up to 140 GPa), and ease of surface modification. However, controlling the properties of CNC is still challenging, given the wide variety of pulp sources and the complexity of finding suitable processing conditions. In the present study, acid hydrolysis efficiently isolated CNC from wood Acacia mearnsii brown kraft pulp (AMKP). Initially, the AMKP was delignified by the treatment with acidified sodium chlorite. The Acacia mearnsii kraft pulp obtained was then subjected to acid hydrolysis with sulfuric acid at concentrations of 50 to 58% 45 °C for 60 min. The hydrolysate was sonicated in an ultrasonic processor for 30 min. The chemical composition was determined by Fourier transform infrared spectroscopy (FTIR), crystallinity by X-ray diffraction (XRD), zeta potential by Zetasizer ZS equipment, thermal stability by thermogravimetric analysis (TGA), and morphology by transmission electron microscopy (TEM) to verify the effect of acid concentration on the yield and properties of CNC. The optimization of the isolation process demonstrated that the maximum yield of 41.95% can be obtained when AMWP was hydrolyzed with sulfuric acid at a concentration of 54%. It was possible to isolate CNC with a crystallinity index between 71.66% and 81.76%, with the onset of thermal degradation at 240 °C; zeta potential of −47.87 to 57.23 mV; and rod-like morphology, with lengths and widths between 181.70 nm and 260.24 nm and 10.36 nm and 11.06 nm, respectively. Sulfuric acid concentration significantly affected the yield of acid hydrolysis, allowing the isolation of CNC with variable dimensions, high thermal stability, high crystallinity index, and great colloidal stability in aqueous medium.

Background/Objectives: Cancer is a major health concern involving abnormal cell growth. Combining anticancer agents can enhance efficacy and overcome resistance by targeting multiple pathways and creating synergistic effects. Methods: This study used in silico approaches to evaluate the physicochemical and pharmacokinetic profiles of the innovative organoselenium nucleoside analog Di3a, followed by the design of two nanocarriers. Di3a-loaded PLGA nanocapsules and nanostructured lipid carriers based on compritol were prepared and evaluated alone and combined with doxorubicin (DOX) and docetaxel (DTX) for a synergistic effect. Results: Di3a subtly violated some of Lipinski’s rules, but still showed suitable pharmacokinetic properties. Both nanoparticles presented nanometric size, negative zeta potential and polydispersity index values < 0.20. Hemolysis assay suggested a pH-dependent pattern conferred by the surfactant 77KL, and evidenced the biocompatibility of the formulations, aligning with the results observed in the nontumor L929 cell line. The lack of drug release studies under varying pH conditions constitutes a limitation and warrants further investigation to validate the pH-responsive properties of the nanocarriers. MTT assay revealed that both formulations exhibited significant cytotoxic effects in the A549 cell line. However, neither formulation exhibited marked toxicity toward NCI/ADR-RES, a resistant tumor cell line. Conversely, when combined with DOX or DTX, the treatments were able to sensitize these resistant cells, achieving expressive synergistic antitumor activity. Conclusions: Despite the limitations in the in silico studies, the study highlights the potential of combining the proposed nanocarriers with conventional antitumor drugs to sensitize multidrug-resistant cancer cells and emphasizes the safety of the developed nanoformulations.

In recent years, publications on organoselenium compounds have increased markedly, expanding their applications in therapeutic, nutraceutical, agricultural, and environmental fields. However, intrinsic properties such as high lipophilicity and chemical reactivity often limit their bioavailability and therapeutic performance. Advances in self‐assembled nanostructures have enabled more efficient delivery, improving solubility and bioavailability while reducing toxicity. This review is the first to focus specifically on the physicochemical interactions governing the stability and performance of organoselenium‐based nanostructures. We analyze recent formulations, emphasizing hydrophobic, van der Waals, electrostatic, and hydrogen bonding interactions that control nanocarrier behavior. Additionally, we discuss emerging strategies and future applications for the rational design of safer and more effective organoselenium delivery systems.