Transfection—the introduction of exogenous DNA or RNA into cells—is a cornerstone of liver-directed gene therapy and research. However, beyond the immediate expression of delivered genes, transfection can induce epigenetic changes that regulate how long and how strongly those genes are expressed. In liver cells, epigenetic modulation following transfection encompasses chemical modifications to DNA and histones…
The CRISPR-Cas9 system has revolutionized genome editing, and applying it specifically to the liver holds promise for treating genetic liver diseases and studying gene function. Liver-specific CRISPR-Cas9 transfection involves delivering CRISPR components (Cas9 nuclease and guide RNA) in a manner that confines editing activity largely to hepatocytes. Achieving this specificity via transfection (non-viral delivery) requires…
The therapeutic potential of mRNA (messenger RNA) is now well-established, from vaccines to protein replacement therapies. However, ensuring that delivered mRNA remains stable and translatable in liver cells is a key challenge. mRNA stabilization strategies are employed to prolong the half-life of mRNA and enhance its translation efficiency within hepatocytes. These strategies include chemical modifications…
When developing liver-directed gene therapies or conducting in vitro liver research, scientists often observe that primary human hepatocytes are significantly harder to transfect than immortalized hepatocellular carcinoma (HCC) cell lines (like HepG2, Huh7, or Hep3B). These differences in transfection efficiency stem from multiple biological and physical factors: primary cells are quiescent, have intact plasma membrane…
The liver is a complex organ with not only parenchymal hepatocytes but also a rich population of non-parenchymal cells. Among these, Kupffer cells – the resident macrophages of the liver – play a major role in clearing foreign substances. When gene delivery vectors or transfection reagents are administered for liver transfection, Kupffer cells can rapidly…
Hydrodynamic tail vein injection is a unique physical method for delivering nucleic acids (DNA or RNA) to the liver. Unlike lipid nanoparticles or viral vectors that rely on cellular uptake mechanisms, hydrodynamic injection uses a rapid, high-volume infusion of solution to achieve gene transfer. This technique, often simply called hydrodynamic injection (HDI), can result in…
One of the remarkable features of many liver-directed gene delivery systems is their natural propensity to accumulate in hepatocytes. A key player in this process is Apolipoprotein E (ApoE) – a protein that circulates attached to lipoproteins and can bind to hepatocyte receptors. ApoE has emerged as a critical factor in the targeting of lipid…
Lipid nanoparticles (LNPs) have revolutionized the delivery of nucleic acids to the liver, enabling therapies like siRNA drugs and mRNA vaccines. A critical step in LNP-mediated transfection is endosomal escape – the process by which the payload (DNA or RNA) is released from endosomal vesicles into the cytosol after cellular uptake. Endosomal escape is often…
Liver-targeted gene delivery often relies on hepatocyte-specific promoters to restrict transgene expression to hepatocytes while minimizing off-target effects. These promoters are regulatory DNA sequences that drive gene transcription predominantly in liver cells, such as those controlling albumin or α<sub>1</sub>-antitrypsin genes. Optimizing such promoters is crucial for gene therapy applications aimed at the liver, ensuring high…
RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression, typically by causing the destruction of specific mRNA molecules. As such, it has the potential to be used as a therapeutic tool to silence disease-causing genes. The liver is a particularly promising target for RNAi therapies because of its high capacity…
