Engineering Cellular Membrane for Dual Mode Therapy Using NIR Responsive Photosensitizer and Reversible Topoisomerase Inhibition Activity

Erythrocyte membrane vesicles as drug delivery systems: A systematic review of preclinical studies on biodistribution and pharmacokinetics

This systematic review aims to summarize the development of erythrocyte membrane vesicles (EMVs) as drug delivery carriers, with a focus on elucidating their fate in terms of biodistribution and pharmacokinetics in preclinical studies. The PubMed database was systematically reviewed to search for original peer-reviewed published studies on the use of EMVs for drug delivery to summarize the preclinical findings, following the PRISMA guidelines. A total of 142 articles matched the selection criteria and were included in the review. For each study, the following parameters were extracted: type of active pharmaceutical ingredient (API) encapsulated into EMVs, EMVs-API formulation method and final particle size, EMVs surface modifications for active targeting, cell lines and animal models used in the study, crucial treatment data, biodistribution data and finally, where applicable, data about the EMVs circulation time and blood half-life. EMVs size did not vary significantly among the different formulation methods. A complete list of cell lines and animal models used is provided. Circulation times and data for blood half-life were grouped per animal type. For the most commonly used animal type, BALB/c mice, the average half-life of EMV-API was calculated to be 10.4 h, and in all cases, up to a 10-fold increase was observed compared with that of free API. Surface modifications did not drastically change the circulation time but did improve target tissue accumulation. The most critical weaknesses in the analysed studies were identified. Key points for future studies are provided to fill the current knowledge gaps and improve the quality of publications.

Phytochemicals and Cancer Treatment: Cell-Derived and Biomimetic Vesicles as Promising Carriers

The majority of anticancer agents currently used derive from natural sources: plants, frequently the ones employed in traditional medicines, are an abundant source of mono- and diterpenes, polyphenols, and alkaloids that exert antitumor activity through diverse mechanisms. Unfortunately, many of these molecules are affected by poor pharmacokinetics and limited specificity, shortcomings that may be overcome by incorporating them into nanovehicles. Cell-derived nanovesicles have recently risen to prominence, due to their biocompatibility, low immunogenicity and, above all, targeting properties. However, due to difficult scalability, the industrial production of biologically-derived vesicles and consequent application in clinics is difficult. As an efficient alternative, bioinspired vesicles deriving from the hybridization of cell-derived and artificial membranes have been conceived, revealing high flexibility and appropriate drug delivery ability. In this review, the most recent advances in the application of these vesicles to the targeted delivery of anticancer actives obtained from plants are presented, with specific focus on vehicle manufacture and characterization, and effectiveness evaluation performed through in vitro and in vivo assays. The emerging overall outlook appears promising in terms of efficient drug loading and selective targeting of tumor cells, suggesting further engrossing developments in the future.

Spontaneous Transfer of Indocyanine Green from Liposomes to Albumin Is Inhibited by the Antioxidant α-Tocopherol

Indocyanine Green (ICG) is a clinically approved organic dye with near-infrared absorption and fluorescence. Over the years, many efforts to improve the photophysical and pharmacokinetic properties of ICG have investigated numerous nanoparticle formulations, especially liposomes with membrane-embedded ICG. A series of systematic absorption and fluorescence experiments, including FRET experiments using ICG as a fluorescence energy acceptor, found that ICG transfers spontaneously from liposomes to albumin protein residing in the external solution with a half-life of ∼10 min at 37 °C. Moreover, transfer of ICG from liposome membranes to external albumin reduces light-activated leakage from thermosensitive liposomes with membrane-embedded ICG. A survey of lipophilic liposome additives discovered that the presence of clinically approved antioxidant, α-tocopherol, greatly increases ICG retention in the liposomes (presumably by forming favorable aromatic stacking interactions), inhibits ICG photobleaching and prevents albumin-induced reduction of light-triggered liposome leakage. This new insight will help researchers with the specific task of optimizing ICG-containing liposomes for fluorescence imaging or phototherapeutics. More broadly, the results suggest a broader design concept concerning light triggered liposome leakage, that is, proximity of the light absorbing dye to the bilayer membrane is a critical design feature that impacts the extent of liposome leakage.

Comparative analysis of PEG-liposomes and RBCs-derived nanovesicles for anti-tumor therapy

Lipid-based vesicular nanoparticles, for instance liposomes, conjugated with polyethylene glycol (PEG) have proven to be the closest to an ideal drug delivery vehicle, making way for several PEG-liposomes based nanomedicines in market. However, the synthetic nature of the nanomaterial poses a threat to stimulate immune system. Alternatively, nanovesicles derived from mammalian cells, such as RBCs, have gained interests as they may not elicit much immune response due to the presence of host specific self-recognition markers on their surface. While several reports demonstrating the superior efficacy of these naturally derived vesicles have come out in the last few years, a comparison with clinically established liposomes is still missing. Thus, we conducted an in-vitro and in-vivo comparative studies between PEG-Liposomes and nanovesicles (NVEs) derived from red blood cell (RBC) membrane with an aim to establish a biocompatible nanocarrier for efficient delivery of chemotherapeutic drugs and photothermal agents.