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…
Non-viral gene delivery systems have emerged as a significant area of research due to their potential advantages over viral vectors, including lower immunogenicity, larger cargo capacity, and potential for repeat administration. Here are some non-viral gene delivery systems specifically used for liver-specific gene expression: Despite the potential advantages, non-viral gene delivery systems also face challenges…
Gene delivery to the liver is a complex process and faces many challenges due to both biochemical and biophysical barriers that exist at multiple levels. Here are some of these barriers: Different strategies are being developed to overcome these barriers, such as designing vectors with improved targeting and endosomal escape capabilities, using tissue-specific promoters to…
