Novel Lipid Nanoparticles Stable and Efficient for mRNA Transfection to Antigen-Presenting Cells.

mRNA vaccines have emerged as a pivotal tool in combating COVID-19, offering an advanced approach to immunization. A key challenge with these vaccines is their need for extremely-low-temperature storage, which affects their stability and shelf life. Our research addresses this issue by enhancing the stability of mRNA vaccines through a novel cationic lipid, O,O'-dimyristyl-N-lysyl aspartate (DMKD). DMKD effectively binds with mRNA, improving vaccine stability. We also integrated phosphatidylserine (PS) into the formulation to boost immune response by promoting the uptake of these nanoparticles by immune cells. Our findings reveal that DMKD-PS nanoparticles maintain structural integrity under long-term refrigeration and effectively protect mRNA. When tested, these nanoparticles containing green fluorescent protein (GFP) mRNA outperformed other commercial lipid nanoparticles in protein expression, both in immune cells (RAW 264.7 mouse macrophage) and non-immune cells (CT26 mouse colorectal carcinoma cells). Importantly, in vivo studies show that DMKD-PS nanoparticles are safely eliminated from the body within 48 h. The results suggest that DMKD-PS nanoparticles present a promising alternative for mRNA vaccine delivery, enhancing both the stability and effectiveness of these vaccines.

Tumor-Targeted Erythrocyte Membrane Nanoparticles for Theranostics of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) cells do not contain various receptors for targeted treatment, a reason behind the poor prognosis of this disease. In this study, biocompatible theranostic erythrocyte-derived nanoparticles (EDNs) were developed and evaluated for effective early diagnosis and treatment of TNBC. The anti-cancer drug, doxorubicin (DOX), was encapsulated into the EDNs and diagnostic quantum dots (QDs) were incorporated into the lipid bilayers of EDNs for tumor bio-imaging. Then, anti-epidermal growth factor receptor (EGFR) antibody molecules were conjugated to the surface of EDNs for TNBC targeting (iEDNs). According to the confocal microscopic analyses and biodistribution assay, iEDNs showed a higher accumulation in EGFR-positive MDA-MB-231 cancers in vitro as well as in vivo, compared to untargeted EDNs. iEDNs containing doxorubicin (iEDNs-DOX) showed a stronger inhibition of target tumor growth than untargeted ones. The resulting anti-EGFR iEDNs exhibited strong biocompatibility, prolonged blood circulation, and efficient targeting of TNBC in mice. Therefore, iEDNs may be used as potential TNBC-targeted co-delivery systems for therapeutics and diagnostics.

EGF Receptor-Targeting Cancer Therapy Using CD47-Engineered Cell-Derived Nanoplatforms.

Introduction: Avoiding phagocytic cells and reducing off-target toxicity are the primary hurdles in the clinical application of nanoparticles containing therapeutics. For overcoming these errors, in this study, nanoparticles expressing CD47 proteins inhibiting the phagocytic attack of immune cells were prepared and then evaluated as an anti-cancer drug delivery vehicle. Methods: The CD47+ cell-derived nanoparticles (CDNs) were prepared from the plasma membranes of human embryonic kidney cells transfected with a plasmid encoding CD47. And the doxorubicin (DOX) was loaded into the CDNs, and anti-EGF receptor (EGFR) antibodies were conjugated to the surface of the CDNs to target tumors overexpressing EGFR. Results: The CD47+iCDNs-DOX was successfully synthesized having a stable structure. The CD47+CDNs were taken up less by RAW264.7 macrophages compared to control CDNs. Anti-EGFR CD47+CDNs (iCDNs) selectively recognized EGFR-positive MDA-MB-231 cells in vitro and accumulated more effectively in the target tumor xenografts in mice. Moreover, iCDNs encapsulating doxorubicin (iCDNs-DOX) exhibited the highest suppression of tumor growth in mice, presumably due to the enhanced DOX delivery to tumor tissues, compared to non-targeting CDNs or CD47- iCDNs. Discussion: These results suggest that the clinical application of biocompatible cell membrane-derived nanocarriers could be facilitated by functionalization with macrophage-avoiding CD47 and tumor-targeting antibodies.