Structural features and biomedical applications of nanobodies

Monoclonal antibody is an important tool in modern biomedicine, which is widely used in disease diagnosis, treatment and basic research. However, its large molecular weight, relative molecular weight and complex structure limit its ability to recognize cryptic epitopes, and it may still trigger immune responses after humanization. Therefore, novel antibodies are urgently needed to overcome these shortcomings. Nanoantibody is a single domain antibody fragment extracted from camel heavy chain antibody and a new antigen receptor immunoglobulin derived from cartilaginous fish. It has the characteristics of small molecular weight, high affinity, high specificity, excellent thermal stability and low off target effect. These characteristics make it show broad prospects in the fields of cancer treatment, diagnostic imaging and anti-inflammatory treatment. This paper reviews the structural characteristics of nanoantibodies and their advantages over traditional monoclonal antibodies, systematically discusses their application progress in tumor targeted therapy, immunotherapy, anti-inflammatory therapy and medical diagnosis, and analyzes the latest development of their screening technology, humanized transformation and production process. The review also discusses the challenges faced by the current research and the future direction, which provides a scientific reference for further research and clinical translation of nanoantibodies.