Strategies for optimizing polymer lipid hybrid nanoparticle mediated drug delivery
Polymer lipid hybrid nanoparticles (PLN) are an emerging nanoparticle drug delivery system made of polymers and lipids taking advantages of both materials. PLN are solid at body temperature, which is similar to solid lipid nanoparticles (SLN)[1,2] but different from the traditionally referred lipidbased nanoparticles liposomes that consist of an aqueous core enclosed in a lipid bilayer. The coexistence of polymer and lipid possessing different material properties, such as hydrophobicity and water solubility, imparts PLN versatile capability of loading varying types of payloads, which is different from SLN and nanostructured lipid carriers that are mainly for loading hydrophobic compounds. Compared to other types of nanoparticle drug carriers, PLN exhibit a number of unique advantages including (1) wide selections of biocompatible polymers and lipids and numerous polymer lipid combinations, (2) easy fabrication by a single step method, and (3) superior capability of co encapsulating therapeutic and imaging agents of different properties. PLN formulations have been demonstrated to increase drug loading efficiency, enable controlled drug release, improve drug uptake and intracellular drug transport, and circumvent membrane efflux transportermediated multidrug resistance (MDR) in cancer cells. Like other types of nanocarriers, PLN can also be conjugated with targeting moieties for targeted drug delivery to tumor vasculature and tumor cells. Because of these advantages, PLN system is of tremendous potential for delivery of a broad range of therapeutic agents. However, it is challenging to design optimal formulations with all desirable characteristics for specific applications such as cancer chemotherapy. This editorial article provides an overview of PLN formulations with a focus on injectables for cancer therapy, representative examples, and discusses the key factors, strategies, and future in the development of PLN for effective delivery of individual or combinatorial therapeutic agents.
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