Nanobodies: emerging tools for clinical applications

Since the introduction of heavy-chain antibodies (HcAbs) two decades ago and the explanation of nanobodies, valuable biochemical
properties of nanobodies have generated the interest of researchers on their use in diagnosis and therapy of tumor. Various specific
nanobodies (VHHs or sdAbs) have been selected from library and detected high affinity with their antigens. The small size of
nanobodies (~15 kDa, 4 nm long and 2.5 nm wide) make it easy for them to penetrate the tissue or get through the blood brain barrier
as drugs. Furthermore, nanobodies have been offered in conjugates with other effector domains and in drug delivery systems as
targeting for tumors. The nanobodies has the potential to make effective biomedical carriers in the fields of research, diagnostics and
therapy. In this review we have explained the important advances in the field of nanobodies. Nevertheless, there are many potentials
to further develop and improve nanobody-mediated tumor targeting. In the near future, new targets and their corresponding nanobodies
must be identified. Currently, some researchers exploited available nanobodies against tumor-specific receptors for delivering drugs or
toxins to tumors, therewith reducing nonspecific toxicity to normal cells and lessening side effects. In conclusion, nanobodies as
targeting carrier appear to be a promising method of tumor targeting therapy and diagnosis