Efficient tuning of siRNA dose response by combining mixed polymer nanocarriers with simple kinetic modeling

Abstract

Two of the most prominent challenges that limit the clinical success of siRNA therapies are a lack of control over cargo release from the delivery vehicle and an incomplete understanding of the link between gene silencing dynamics and siRNA dosing. Herein, we address these challenges through the formulation of siRNA polyplexes containing light-responsive polymer mixtures, whose varied compositions and triggered release behavior provide enhanced gene silencing and controlled dose responses that can be predicted by simple kinetic models. Through the straightforward mixing of two block copolymers, the level of gene knockdown was easily optimized to achieve the maximum level of GAPDH protein silencing in NIH/3T3 cells (70%) using a single siRNA dose. The kinetic model was used to describe the dynamic changes in mRNA and protein concentrations in response to siRNA treatment. These predictions enabled the application of a second dose of siRNA to maximally suppress gene expression over multiple days, leading to a further 50% reduction in protein levels relative to those measured following a single dose. Furthermore, polyplexes remained dormant in cells until exposed to the photo-stimulus, demonstrating the complete control over siRNA activity as well as the stability of the nanocarriers. Thus, this work demonstrates that pairing advances in biomaterials design with simple kinetic modeling provides new insight into gene silencing dynamics and presents a powerful strategy to control gene expression through siRNA delivery.

Attenuation of Maladaptive Responses in Aortic Adventitial Fibroblasts through Stimuli‐Triggered siRNA Release from Lipid–Polymer Nanocomplexes

“…[21] None of the polyplex formulations were able to mediate efficient gene silencing in AoAFs (Figure 1). We suspected that a lack of endosomal escape might be the limiting factor, based on prior evidence demonstrating that human primary cells often are refractory to transfection.…”

“…For the on/off photo-controlled protein silencing experiments, two separate control formulations were used: lipoplexes made with Lipofectamine RNAiMAX according to the manufacturer’s protocol and polyplexes formed as described previously. [21] …”

Quercetin Inhibits Lef1 and Resensitizes Docetaxel-Resistant Breast Cancer Cells

“…Moreover, the discrete reduce in Lef1, resulted also in a very low decrease in its downstream protein expression, including ABCG2 and Vim. One possible reason for this could be the moderate half-life of Lef1 [23] and the difficulty of siRNA to eliminate proteins with long half-life times [24,25]. To overcome this problem, we decided to investigate the effects of small molecules, which could inhibit Lef1 at the protein level to exhort a stronger effect on docetaxel drug resistant cells.…”

Remote Light‐Responsive Nanocarriers for Controlled Drug Delivery: Advances and Perspectives

“…With the rapid development of nanobiotechnology, synthetic stimuli‐responsive biomaterials have drawn significant attention due to their promising applications in fields of biomedicine and pharmacy, such as drug delivery, biosensor, and tissue adhesion . Such materials display rapid changes in structure, solubility or polarity upon external (e.g., temperature, light, mechanical force, and electrical or magnetic field) or internal (e.g., pH, redox, and enzyme) triggers . The use of these materials as drug nanocarriers could accurately deliver drugs at the target sites in a controlled and safe manner, thus avoiding toxic side effects caused by damaging the healthy tissues …”