Magnetic Platelets as a Platform for Drug Delivery and Cell Trapping

A Review: Surface Engineering of Lipid-Based Drug Delivery Systems

This review explores the evolution of lipid-based nanoparticles (LBNPs) for drug delivery (DD). Herein, LBNPs are classified into liposomes and cell membrane-based nanoparticles (CMNPs), each with unique advantages and challenges. Conventional LBNPs possess drawbacks such as poor targeting, quick clearance, and limited biocompatibility. One of the possible alternatives to overcome these challenges is surface modification of nanoparticles (NPs) with materials such as polyethylene glycol (PEG), aptamers, antibody fragments, peptides, CD44, hyaluronic acid, folic acid, palmitic acid, and lactoferrin. Thus, the main focus of this review will be on the different surface modifications that enable LBNPs to have beneficial properties for DD, such as enhancing mass transport properties, immune evasion, improved stability, and targeting. Moreover, various CMNPs are explored used for DD derived from cells such as red blood cells (RBCs), platelets, leukocytes, cancer cells, and stem cells, highlighting their unique natural properties (e.g., biocompatibility and ability to evade the immune system). This discussion extends to the biomimicking of hybrid NPs accomplished through the surface coating of synthetic (mainly polymeric) NPs with different cell membranes. This review aims to provide a comprehensive resource for researchers on recent advances in the field of surface modification of LBNPs and CMNPs. Overall, this review provides valuable insights into the dynamic field of lipid-based DD systems.

A Platelet-Powered Drug Delivery System for Enhancing Chemotherapy Efficacy for Liver Cancer Using the Trojan Horse Strategy

Optimizing the delivery and penetration of nano-sized drugs within liver cancer sites, along with remodeling the tumor microenvironment, is crucial for enhancing the efficacy of chemotherapeutic agents. For this study, a platelet (PLT)-mediated nanodrug delivery system (DASA+ATO@PLT) was developed to improve the effectiveness of chemotherapy. This system delivers nano-sized dasatinib and atovaquone specifically to liver tumor sites and facilitates intra-tumoral permeation upon release. Through JC-1, immunohistochemistry, and DNA damage analyses, the therapeutic effect of DASA+ATO@PLT was assessed. In vitro simulation and intravital imaging were carried out to determine the accumulation of dasatinib and atovaquone in liver tumor sites. The experiment demonstrated the accumulation of dasatinib and atovaquone in tumor sites, followed by deep permeation in the tumor microenvironment with the assistance of PLTs, while simultaneously revealing the ability of DASA+ATO@PLT to remodel the liver cancer microenvironment (overcoming hypoxia) and enhance chemotherapeutic efficacy. This system utilizes the natural tumor recognition ability of PLTs and enhances the chemo-immunotherapeutic effect through targeted delivery of nano-chemotherapeutic drugs to the tumor, resulting in effective accumulation and infiltration. The PLT-mediated nanodrug delivery system serves as a "Trojan horse" to carry therapeutic drugs as cargo and deliver them to target cells, leading to favorable outcomes.

Magnetically navigated microbubbles coated with albumin/polyarginine and superparamagnetic iron oxide nanoparticles

While microbubbles (MB) are routinely used for ultrasound (US) imaging, magnetic MB are increasingly explored as they can be guided to specific sites of interest by applied magnetic field gradient. This requires the MB shell composition tuning to prolong MB stability and provide functionalization capabilities with magnetic nanoparticles. Hence, we developed air-filled MB stabilized by a protein-polymer complex of bovine serum albumin (BSA) and poly-L-arginine (pArg) of different molecular weights, showing that pArg of moderate molecular weight distribution (15-70 kDa) enabled MB with greater stability and acoustic response while preserving MB narrow diameters and the relative viability of THP-1 cells after 48 h of incubation. After MB functionalization with superparamagnetic iron oxide nanoparticles (SPION), magnetic moment values provided by single MB confirmed the sufficient SPION deposition onto BSA + pArg MB shells. During MB magnetic navigation in a blood vessel mimicking phantom with magnetic tweezers and in a Petri dish with adherent mouse renal carcinoma cell line, we demonstrated the effectiveness of magnetic MB localization in the desired area by magnetic field gradient. Magnetic MB co-localization with cells was further exploited for effective doxorubicin delivery with drug-loaded MB. Taken together, these findings open new avenues in control over albumin MB properties and magnetic navigation of SPION-loaded MB, which can envisage their applications in diagnostic and therapeutic needs.