A new nano hyperbranched ß-pinene polymer: Controlled synthesis and nonviral gene delivery.

Recently, an extensive research effort has been directed toward the improvement of nonviral transfection vectors, such as polymeric materials. The macromolecular structure of polymers has a substantial effect on their transfection efficacy. In this context, the modern advances in polymer production techniques, such as the deactivation-enhanced radical atom transfer polymerization (DE-ATRP), have been fundamental for the synthesis of controlled architecture nanomaterials. In this study, hyperbranched poly(ß-pinene)-PDMAEMA-PEGDMA nanometric copolymers were synthesised at high conversion via DE-ATRP using different concentrations of ß-pinene for gene delivery applications. The structural characterization and the biological performance of the materials were investigated. The copolymers' molar mass (10,434-16,438 mol l-1), dispersity, and conversion (90-95%) varied significantly with ß-pinene proportion on the polymerizations. The polymer-gene complexes generated (280-110 nm) presented excellent solution stability due to the ß-pinene segment on the copolymers. Gene delivery and transfection were highly dependent on the copolymer composition. The copolymers containing the highest ß-pinene proportions exhibited the best results with high transfection effectivity. In conclusion, the incorporation of ß-pinene in DMAEMA-PEGMA copolymer formulations is a renewable option to improve the materials' branching ratio, polyplex stability, and gene delivery performance without causing cytotoxic effects.

Simultaneous production of polyhydroxyalkanoate and xanthan gum: From axenic to mixed cultivation.

In the present study, mixed and axenic submerged cultures of Cupriavidus necator and Xanthomonas campestris were performed for simultaneous and individual PHA and XG productions using palm oil (Elaeis guineensis) as substrate. Rotational Central Compound Design (RCCD) was successfully used in the optimization of individual productions of PHA (3.39 g L-1, Mw = 692.6 kDa) and XG (1.77 g L-1, Mw = 36.6 × 105 kDa). Novel simultaneous production of PHA (6.43 g L-1, Mw = 629.2 kDa) and XG (1.98 g L-1, Mw = 25.0 × 105 kDa), executed in bacterial co-cultivation, revealed to be a successful strategy to increment polymer synthesis, especially PHA. XG bioconversions followed a general trend of lower production in co-culture. Culture configurations also altered polymers properties and characteristics.

Evaluation of buriti endocarp as lignocellulosic substrate for second generation ethanol production.

The production of lignocellulosic ethanol is one of the most promising alternatives to fossil fuels; however, this technology still faces many challenges related to the viability of the lignocellulosic alcohol in the market. In this paper the endocarp of buriti fruit was assessed for ethanol production. The fruit endocarp was characterized physically and chemically. Acid and alkaline pre-treatments were optimized by surface response methodology for removal of hemicellulose and lignin from the biomass. Hemicellulose content was reduced by 88% after acid pretreatment. Alkaline pre-treatment reduced the lignin content in the recovered biomass from 11.8% to 4.2% and increased the concentration of the cellulosic fraction to 88.5%. The pre-treated biomass was saccharified by the action of cellulolytic enzymes and, under optimized conditions, was able to produce 110 g of glucose per L of hydrolyzate. Alcoholic fermentation of the enzymatic hydrolyzate performed by Saccharomyces cerevisiae resulted in a fermented medium with 4.3% ethanol and a yield of product per substrate (YP/S) of 0.33.