No abstract

Dual responsive nanoparticles are developed for co-delivery of multiple anticancer drugs to target the drug resistance mechanisms of cancer stem-like cells (CSCs). The nanoparticles consist of four polymers approved by the Food and Drug Administration (FDA) for medical use: Poly(D,L-lactide-co-glycolide) (PLGA), Pluronic F127 (PF127), chitosan, and hyaluronic acid (HA). By combining PLGA and PF127 together, more stable and uniform-sized nanoparticles can be obtained than using PLGA or PF127 alone. The HA is used for not only actively targeting CSCs to reduce their drug resistance due to dormancy (i.e., slow metabolism), but also replacing the commonly used poly(vinyl alcohol) as a stabilizing agent to synthesize the nanoparticles using the double-emulsion approach and to allow for acidic pH-triggered drug release and thermal responsiveness. Besides minimizing drug efflux from CSCs, the nanoparticles encapsulated with doxorubicin hydrochloride (DOX, hydrophilic) and irinotecan (CPT, hydrophobic) to inhibit the activity of topoisomerases II and I, respectively, can fight against the CSC drug resistance associated with their enhanced DNA repair and anti-apoptosis. Ultimately, the two drugs-laden nanoparticles can be used to efficiently destroy the CSCs both in vitro and in vivo with up to ~500 times of enhancement compared to the simple mixture of the two drugs.

Coaxial electrospray is an electrohydrodynamic process that produces multilayer microparticles and nanoparticles by introducing coaxial electrified jets. In comparison with other microencapsulation/nanoencapsulation processes, coaxial electrospray has several potential advantages such as high encapsulation efficiency, effective protection of bioactivity and uniform size distribution. However, process control in coaxial electrospray is challenged by the multiphysical nature of the process and the complex interplay of multiple design, process and material parameters. This paper reviews the previous works and the recent advances in design, modeling and control of a coaxial electrospray process. The review intends to provide general guidance for coaxial electrospray and stimulate further research and development interests in this promising microencapsulation/nanoencapsulation process.

This review presents an overview of the recent advances in the development of stimuli-responsive nanobubbles and their novel biomedical applications including bio-imaging, drug delivery and ablation of tumor tissues.