Lipidoids: A Combinatorial Approach to siRNA Delivery

Targeted siRNA nanotherapeutics against breast and ovarian metastatic cancer: a comprehensive review of the literature

Metastasis is considered the major cause of unsuccessful cancer therapy. The metastatic development requires tumor cells to leave their initial site, circulate in the blood stream, acclimate to new cellular environments at a remote secondary site and endure there. There are several steps in metastasis, including invasion, intravasation, circulation, extravasation, premetastatic niche formation, micrometastasis and metastatic colonization. siRNA therapeutics are appreciated for their usefulness in treatment of cancer metastasis. However, siRNA therapy as a single therapy may not be a sufficient option for control of metastasis. By combining siRNA with targeting, functional agents or small-molecule drugs have shown potential effects that enhance therapeutic effectiveness. This review addresses multidrug resistance and metastasis in breast and ovarian cancers and highlights drug-delivery strategies using siRNA therapeutics.

Formulation of RNA interference-based drugs for pulmonary delivery: challenges and opportunities

With recent advances in the field of RNAi-based therapeutics, it is possible to make any target gene 'druggable', at least in principle. The present review focuses on aspects critical for pulmonary delivery of formulations of nucleic acid-based drugs. The first part introduces the therapeutic potential of RNAi-based drugs for the treatment of lung diseases. Subsequently, we discuss opportunities for formulation-enabled pulmonary delivery of RNAi drugs in light of key physicochemical properties and physiological barriers. In the following section, an overview is included of methodologies for imparting inhalable characteristics to nucleic acid formulations. Finally, we review one of the bottlenecks in the early preclinical testing of inhalable nucleic acid-based formulations, in other words, devices suitable for pulmonary administration of powder-based formulations in rodents.

Combinatorial library strategies for synthesis of cationic lipid-like nanoparticles and their potential medical applications

The past two decades have witnessed the high efficiency and efficacy of cationic lipids and liposomal formations for drug delivery. The tedious synthesis of conventional lipids and the inefficiency in studying structure-activity relationships, however, have hindered the clinical translation of lipid nanoparticle delivery systems. Combinatorial synthesis of lipid-like nanoparticles ('lipidoids') has recently emerged as an approach to accelerate the development of these delivery platforms. Utilizing a high-throughput screening strategy, the libraries of lipidoids are sorted and prime candidates for the delivery in the intended application can be identified and optimized for the next generation. In this review, we outline methods used for combinatorial lipidoid synthesis, the application of high-throughput screening, and the current medical applications of candidate lipidoids.