Polysaccharides (especially chitosan) have recently attracted much attention as gene therapy delivery vehicles for their unique properties such as biocompatibility, biodegradability, low toxicity, and controlled release. Nanoparticles have strong potential as a carrier of plasmid short hairpin RNA (p-shRNA). This study aimed to find the optimum conditions for obtaining Chitosan/triphosphate (TPP)/p-shRNA nanoparticles by the ionic gelation method, and investigating the cellular uptake of the optimized nanoparticles. After applying the central composite design of response surface methodology (RSM), the optimum conditions for preparation of nanoparticles with small size and high loading efficiency were: chitosan/TPP ratio = 10, pH = 5.5 and N/P ratio = 11. The resulting nanoparticles had an average size of 172.8 ± 7 nm and loading efficiency of 71.5 ± 5%. SEM images showed spherical and smooth nanoparticles. The nanoparticles complexed with p-shRNA and may protect it against nuclease digestion. Cytotoxicity studies with HeLa and PC3 human cancer cells demonstrated that chitosan/TPP nanoparticles had low toxicity. Cellular uptake studies using HeLa cells showed that the nanoparticles entered the cells (cellular uptake) and delivered DNA, probably due to their favorable Zeta potential (approximately +28 mV) and small size.

No abstract

No abstract

Sugarcane bagasse hydrolysis was optimized by dilute‐acid pretreatment and subsequent enzymatic treatment. The studied parameters were microwave heating temperature, residence time, and enzyme dosage as the main factors in a central composite design. The amount of released total reducing sugars, glucose, pentose, phenolic compounds, and furfural were measured after each stage. The optimum conditions with suitable concentrations of inhibitors and reducing sugars were applied for bioethanol production. As an example, ethanol was obtained from reducing sugars by Pichia stipitis without detoxification.