Search

Nanosized extracellular vesicles (nEV) are released by all the eukaryotic cells into the extracellular spaces. They serve as crucial mediators of intercellular communication, and their presence has been detected in a variety of body fluids. nEV carry nucleic acids, lipids, proteins, and metabolites from the donor cells and transfer them to the recipient cells in the vicinity or distant locations to cause changes in their biological phenotypes. This very property of nEV makes them a suitable carrier of the drugs for therapeutic applications. The use of nEV as a drug delivery system offers several advantages over synthetic nanoparticles, including biocompatibility, natural targeting ability, and long-term safety. Further, nEV can be isolated from various biological sources, quickly loaded with the drug of choice, and modified to further enhance their utility as targeted drug delivery vehicles. Here we review these aspects of nEV and discuss the parameters that should be kept in mind while choosing the nEV source, drug loading method, and surface modification strategies. We also discuss the challenges associated with the nEV-based drug delivery platforms that must be overcome before realizing their full potential in clinical applications.

The aim of this research work is to develop polyesteramide [LMPEA] nanocomposite coating material [LMPEA/Ag] using N,N-bis(2-hydroxyethyl) fatty amide obtained from non-edible Leucaena leucocephala [LL] seed oil [LLO], and maleic anhydride, reinforced with silver nanoparticles [SNPs], biosynthesized in Leucaena leucocephala leaf extract. UV, XRD, TEM, and particle size analyses confirmed the biosynthesis of NP (37.55 nm). FTIR and NMR established the structure of LMPEA formed by esterification reaction, without any solvent/diluent. Coatings were mechanically strong, well adherent to substrate, flexibility retentive, hydrophobic, and antimicrobial as evident from good scratch hardness (2-3 kg), impact resistance (150 lb per inch), bend test (1/8 inch), high water contact angle measurement value (109°) relative to pristine LMPEA coating (89°), and broad-spectrum antimicrobial behavior against MRSA, P. aeruginosa, E. coli, A. baumannii, and C. albicans. LMPEA and LMPEA/Ag exhibited high corrosion protection efficiencies, 99.81% and 99.94%, respectively, in (3.5% w/v) NaCl solution for 20 days and safe usage up to 200 °C. The synthesized nanocomposite coatings provide an alternate pathway for utilization of non-edible Leucaena leucocephala seed oil through a safer chemical synthesis route, without the use/generation of any harmful solvent/toxic products, adopting "Green Chemistry" principles.

Honokiol is a phytochemical isolated from the Magnolia plant. It exhibits significant antitumor activity against a variety of cancer cell types via targeting of critical mediators of tumor progression, stromal remodeling, and chemoresistance. However, poor bioavailability and inefficient tumor uptake remain some of the hurdles in its translation as a therapeutically useful drug. Here, we developed a nanoformulation of honokiol using mesenchymal stem cell-derived exosomes, which are nonimmunogenic and express surface markers to support their tumor-targeted delivery. Maximum entrapment of honokiol occurred when it was mixed in a 1:4 weight ratio with exosomes and subjected to six cycles of sonication. Dynamic light scattering analysis demonstrated that the average size (∼175.3 nm), polydispersity (∼0.11), and integrity (∼12.9 mV) of exosomes remained in the desirable range post honokiol encapsulation. Exosome-encapsulated honokiol exhibited significantly higher therapeutic efficacy over the free honokiol in WST-1 growth and long-term clonogenicity assays. Flow cytometry-based cell cycle and live/dead cell assay, respectively, confirmed the enhanced effect of exosomal honokiol formulation on cell cycle arrest and apoptosis induction. More significant alterations in the expression of cell cycle- and survival-associated proteins were also observed in cancer cells treated with exosomal honokiol over free honokiol. Higher intracellular accumulation of honokiol was recorded in cancer cells treated with equivalent doses of honokiol as compared to the free honokiol. Together, our work is the first demonstration of exosomal encapsulation of honokiol and its improved antitumor efficacy resulting from improved cellular uptake.