Single-chain variable fragment (scFv) consists of the smallest functional antigen-binding domain of an antibody, in which variable heavy and variable light chains are joined together by a flexible peptide linker.

scFv retains the binding specificity of the parent antibody and offer several advantages over monoclonal antibodies. scFv displays improved pharmacokinetic properties, such as better tissue penetration, rapid blood clearance, and low immunogenicity which makes better therapeutic agents.

Although scFv has higher tissue penetration compared to antibodies, it still requires delivery technology for higher efficacy. Delivering scFv to targeting area is one of the main obstacles in developing scFv as a therapeutic candidate. To intracellularly localize scFv, many research organizations have tried variety delivery technologies such as nanoparticles, adeno-associated virus (AAV), and cell-penetrating peptides. Cellivery applied its technology Therapeuticmolecule Systemic Delivery Technology (TSDT) to scFv and developed Cell-Permeable CV-16

Despite various advantages of scFv, it has obstacles to become a therapeutic agent due to the lack of a suitable means of delivery. CV-16 will provide efficient and effective delivery system to intracellularly localize scFv in targeted cells for its highest efficacy. CV-16 will expand applications of scFv which will ultimately help patients in need.