Exploring the design space of AAV transient-transfection in suspension cell lines.

The safety and utility of adeno-associated virus (AAV) to modulate target gene expression has been well demonstrated, and AAV vectors are a leading gene therapy platform. However, manufacturing presents challenges in terms of productivity and scalability as compared to incumbent therapeutic modalities. In particular, a pivot from adherent cell- to suspension culture-based AAV manufacturing processes requires enhanced study of the transfection step. For the method proposed herein, a Response Surface Design of Experiments is suggested to explore the role of five transfection factors-cell density at transfection, DNA concentration, ratio of complexing reagent to DNA, and molar ratios of the transfecting plasmids-influencing viral genome titer and biological potency. Additionally, an AAV categorical factor matrix is presented for developing a workflow to interrogate the impact of AAV permutations for different capsid serotypes, harbored genes of interest, and inverted terminal repeat configurations on transfection process parameters.

Interplay of Dynamical Properties between Ionic Liquids and Ionic Surfactants: Mechanism and Aggregation.

The dynamical and aggregation behaviors of sodium dodecyl sulfate (SDS) in 1-ethyl-3-methylimidazolium ethylsulfate [EMIM+][EtSO4­] are characterized experimentally and computationally. A retardation of the ionic liquid (IL) and SDS diffusion coefficients with a concentration increase of SDS is observed. In agreement with experiments, aggregation is detected for concentrations higher than the experimental critical micelle concentration (CMC), which is mostly driven by alkyl tail aggregation. Solvent-exposed hydrophobic patches are observed on the micelle's surfaces. The hydrophobic tails of the IL molecules are found to fill those micelle's hydrophobic patches. Also, penetration of the IL is found in the SDS micelles, indicating that the IL acts as a cosurfactant, allowing the formation of "mixed" micelles. A higher level of Na+ counterion dissociation compared to previous studies of SDS micelles in aqueous solutions is also observed. A multilayering effect of alternating IL anions and cations is detected at the surface of the formed aggregates. The observed increase in system ordering with SDS concentration is what hinders the mobility of each chemical species.