No abstract

Background: Lipidic nanocarriers have great potential for the encapsulation and delivery of numerous bioactive compounds. They have demonstrated significant benefits over traditional disease management and conventional therapy. The benefits associated with the particular properties of lipidic nanocarriers include site-specific drug deposition, improved pharmacokinetics and pharmacodynamics, enhanced internalization and intracellular transport, biodegradability, and decreased biodistribution. These properties result in the alleviation of the harmful consequences of conventional treatment protocols. Scope and approach: The administration of various bioactive molecules has been extensively investigated using nanostructured lipid carriers. In this article, theranostic applications of novel formulations of lipidic nanocarriers combined or complexed with quantum dots, certain polymers such as chitosan, and metallic nanoparticles (particularly gold) are reviewed. These formulations have demonstrated better controlled release features, improved drug loading capability, as well as a lower burst release rate. As a recent innovation in the field of drug delivery, tocosomes and their unique advantages are also explained in the final section of this entry. Key findings and conclusions: Theranostic medicine requires nanocarriers with improved target-specific accumulation and bio-distribution. Towards this end, lipid-based nanocarrier systems and tocosomes combined with unique properties of quantum dots, biocompatible polymers, and metallic nanoparticles seem to be ideal candidates to be considered for safe and efficient drug delivery.

No abstract

Exosomes are natural membrane-enclosed nanovesicles (30–150 nm) involved in cell-cell communication. Recently, they have garnered considerable interest as nanocarriers for the controlled transfer of therapeutic agents to cells. Here, exosomes were derived from bone marrow mesenchymal stem cells (BM-MSCs) using three different isolation methods, and the size exclusion chromatography (SEC) led to the isolation with the highest purity. The limitation of using pure exosomes for encapsulating large nucleic acids was then addressed by the development of exosome-liposome hybrids. The efficiency of these hybrids to transfer the Cas9-green fluorescent protein plasmid (pCas9-GFP) into the human embryonic kidney 293T (HEK293T) cells were evaluated compared to the pure exosomes. The method of combining exosomes with liposomes (freeze-thaw vs. direct mixing) was proved to be more decisive in determining the size of the vesicular hybrids. In contrast, the ionic nature of the liposomes (lipoplex vs. cationic) in these hybrids was proved to be more important in determining the transfection efficiency. Both Cas9-GFP-loaded exosomes and exosome-liposome hybrids were taken up well by the HEK293T and were able to transfect them with their plasmid loads; however, the pure exosome and then the vesicular hybrids incorporating lipoplex transfected the cells more efficiently than those containing cationic liposomes.