A cationic lipid with advanced membrane fusion performance for pDNA and mRNA delivery

Leveraging high-throughput screening technologies in targeted mRNA delivery

Messenger ribonucleic acid (mRNA) has emerged as a promising molecular preventive and therapeutic approach that opens new avenues for healthcare. Although the use of delivery systems, especially lipid nanoparticles (LNPs), greatly improves the efficiency and stability of mRNA, mRNA tends to accumulate in the liver and hardly penetrates physiological barriers to reach the target site after intravenous injection. Hence, the rational design of targeting strategies aimed at directing mRNA to specific tissues and cells remains an enormous challenge in mRNA therapy. High-throughput screening (HTS) is a cutting-edge targeted technique capable of synthesizing chemical compound libraries for the large-scale experiments to validate the efficiency of mRNA delivery system. In this review, we firstly provide an overview of conventional low-throughput targeting strategies. Then the latest advancements in HTS techniques for mRNA targeted delivery, encompassing optimizing structures of large-scale delivery vehicles and developing large-scale surface ligands, as well as the applications of HTS techniques in extrahepatic systemic diseases are comprehensively summarized. Moreover, we illustrate the selection of administration routes for targeted mRNA delivery. Finally, challenges in the field and potential solutions to tackle them are proposed, offering insights for future development toward mRNA targeted therapy.

Fibrous topology promoted pBMP2-activated matrix on titanium implants boost osseointegration

Titanium (Ti) implants have been extensively used after surgical operations. Its surface bioactivity is of importance to facilitate integration with surrounding bone tissue, and ultimately ensure stability and long-term functionality of the implant. The plasmid DNA-activated matrix (DAM) coating on the surface could benefit osseointegration but is still trapped by poor transfection for further application, especially on the bone marrow mesenchymal stem cells (BMSCs) in vivo practical conditions. Herein, we constructed a DAM on the surface of fibrous-grained titanium (FG Ti) composed of phase-transition lysozyme (P) as adhesive, cationic arginine-rich lipid (RLS) as the transfection agent and plasmid DNA (pDNA) for bone morphology protein 2 (BMP2) expression. The cationic lipid RLS improved up to 30-fold higher transfection than that of commercial reagents (Lipofectamine 2000 and polyethyleneimine) on MSC. And importantly, Ti surface topology not only promotes the DAM to achieve high transfection efficiency (∼75.7% positive cells) on MSC due to the favorable combination but also reserves its contact induction effect for osteoblasts. Upon further exploration, the fibrous topology on FG Ti could boost pDNA uptake for gene transfection, and cell migration in MSC through cytoskeleton remodeling and induce contact guidance for enhanced osteointegration. At the same time, the cationic RLS together with adhesive P were both antibacterial, showing up to 90% inhibition rate against Escherichia coli and Staphylococcus aureus with reduced adherent microorganisms and disrupted bacteria. Finally, the FG Ti-P/pBMP2 implant achieved accelerated bone healing capacities through highly efficient gene delivery, aligned surface topological structure and increased antimicrobial properties in a rat femoral condylar defect model.

Cellular Trafficking of Nanotechnology-Mediated mRNA Delivery

Messenger RNA (mRNA)-based therapy has emerged as a powerful, safe, and rapidly scalable therapeutic approach that involves technologies for both mRNA itself and the delivery vehicle. Although there are some unique challenges for different applications of mRNA therapy, a common challenge for all mRNA therapeutics is the transport of mRNA into the target cell cytoplasm for sufficient protein expression. This review is focused on the behaviors at the cellular level of nanotechnology-mediated mRNA delivery systems, which have not been comprehensively reviewed yet. First, the four main therapeutic applications of mRNA are introduced, including immunotherapy, protein replacement therapy, genome editing, and cellular reprogramming. Second, common types of mRNA cargos and mRNA delivery systems are summarized. Third, strategies to enhance mRNA delivery efficiency during the cellular trafficking process are highlighted, including accumulation to the cell, internalization into the cell, endosomal escape, release of mRNA from the nanocarrier, and translation of mRNA into protein. Finally, the challenges and opportunities for the development of nanotechnology-mediated mRNA delivery systems are presented. This review can provide new insights into the future fabrication of mRNA nanocarriers with desirable cellular trafficking performance.

Aged-Signal-Eliciting Nanoparticles Stimulated Macrophage-Mediated Programmed Removal of Inflammatory Neutrophils

Excessive infiltration of activated neutrophils is regarded as a predominant cause of tissue injury in neutrophilic inflammation. Although programmed cell death like apoptosis maintains the homeostasis of activated neutrophils, this process is disrupted by an abnormal inflammatory response. Unlike endogenous calreticulin exposed during apoptosis, exogenous calreticulin acts as an "aged" signal and initiates premature macrophage-mediated programmed cell removal (PrCR), which is independent of apoptosis. Here, we report a nano-mediated strategy to stimulate the precise clearance of activated neutrophils initiated with artificial aged signal and alleviated inflammation. Polymeric nanoparticles PC@PLGA were fabricated by cloaking poly(lactic-co-glycolic acid) (PLGA) with a hybrid membrane derived from platelet-derived extracellular vesicles (PEVs, denoted by P) and the calreticulin-expressed membrane obtained from doxorubicin-treated cells (denoted by C). P-selectin in PEVs favors PC@PLGA to anchor activated neutrophils, while calreticulin mimics exogenous "aged" signal secreted by macrophages to trigger PrCR. We showed that PC@PLGA specifically targeted activated neutrophils and misled macrophages to recognize them as "aged" neutrophils and then initiated premature PrCR and prevented proinflammatory response and tissue damage in a mouse model of acute lung injury and severe acute pancreatitis. The collective findings indicate the efficiency of specific elimination of activated neutrophils with exogenous aged signal in improving inflammation therapy.