Gene therapy has been a significant development in medicine for nearly 40 years, focusing on treating genetic disorders by injecting specific genetic material into a patient to alter cell activity and address hereditary illnesses. Four fundamental gene therapy techniques include gene silencing, gene addition, gene replacement, and gene editing. Adeno-associated viruses (AAVs) are a type of gene therapy vehicle that was initially discovered as a contaminant of adenovirus preparations. The first human gene therapy study was conducted in 1970 when American physician Stanfield Rogers tried to cure argininemia with a papillomavirus-containing arginase. The primary vector for in vivo gene therapy delivery is recombinant AAVs (rAAVs). The first rAAV gene therapy treatment, Alipogene tiparvovec (Glybera), received approval in 2012 for lipoprotein lipase deficiency. In 2017, the US FDA approved Luxturna (Voretigene Neparvovec) as the first retinal gene therapy for human use, specifically for patients with LCA type 2, an inherited retinal degeneration caused by mutations in the RPE65 gene. AveXis developed Onasemnogene abeparvovec (Zolgensma®) for spinal muscular atrophy (SMA). This blog summarises the emergence and applications of AAV in gene therapy platform.
Gadolinium based Contrast Agents (GBCAs) in Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) is a crucial technique for disease diagnosis and treatment, with gadolinium-based contrast agents (GBCAs) being useful and safe in some cases. GBCAs are pharmaceuticals that enhance diagnostic image information by altering tissue properties, influencing contrast mechanisms. They are used in MRI to study proton (1H) relaxation processes in water and soft tissues in biological systems. GBCAs are administered intravenously and distributed throughout the body, with most being eliminated within hours. They shorten the T1 and T2 relaxation times of water molecules, resulting in brighter signals on T1-weighted images and darker signals on T2-weighted images. When administered at relatively low doses in individuals with normal renal function, all GBCAs approved for clinical use have a broad safety margin. Understanding an agent’s relaxivity, concentration, and chelate stability is important for radiologists as these properties impact patient safety and the effectiveness of diagnosis. This blog summarizes an overview of Gadolinium based contrast agents usage in the diagnostic MRI imaging.