Synthetic Conjugated Oligoelectrolytes Are Effective siRNA Transfection Carriers: Relevance to Pancreatic Cancer Gene Therapy.

Conjugated oligoelectrolyte COE-S6 contains an elongated conjugated core with three cationic charges at each termini of the internal core. As an analogue of bolaamphiphiles, these structural attributes lead to the formation of spherical nanoplexes with Dh = 205 ± 5.0 nm upon mixing with small interfering RNA (siRNA). COE-S6/siRNA nanocomplexes were shown to be protective toward RNase, stimulate endosome escape, and achieve transfection efficiencies comparable to those achieved with commercially available LIP3000. Moreover, COE-S6/siRNA nanocomplexes enabled efficient silencing of the K-ras gene in pancreatic cancer cells and significant inhibition of cancer tumor growth with negligible in vitro toxicities. More importantly, cell invasion and colony formation of the Panc-1 cells were significantly inhibited, and apoptosis of the pancreatic cancer cells was also promoted. We also note that COE-S6 is much less toxic relative to commercial lipid formulations, and it provides optical signatures that can enable subsequent mechanistic work without the need to label nucleotides. COE-S6-based nanoplexes are thus a promising candidate as nonviral vectors for gene delivery.

Role of microfluidics in accelerating new space missions.

Numerous revolutionary space missions have been initiated and planned for the following decades, including plans for novel spacecraft, exploration of the deep universe, and long duration manned space trips. Compared with space missions conducted over the past 50 years, current missions have features of spacecraft miniaturization, a faster task cycle, farther destinations, braver goals, and higher levels of precision. Tasks are becoming technically more complex and challenging, but also more accessible via commercial space activities. Remarkably, microfluidics has proven impactful in newly conceived space missions. In this review, we focus on recent advances in space microfluidic technologies and their impact on the state-of-the-art space missions. We discuss how micro-sized fluid and microfluidic instruments behave in space conditions, based on hydrodynamic theories. We draw on analyses outlining the reasons why microfluidic components and operations have become crucial in recent missions by categorically investigating a series of successful space missions integrated with microfluidic technologies. We present a comprehensive technical analysis on the recently developed in-space microfluidic applications such as the lab-on-a-CubeSat, healthcare for manned space missions, evaluation and reconstruction of the environment on celestial bodies, in-space manufacturing of microfluidic devices, and development of fluid-based micro-thrusters. The discussions in this review provide insights on microfluidic technologies that hold considerable promise for the upcoming space missions, and also outline how in-space conditions present a new perspective to the microfluidics field.