microAB

microAB is a term used to describe a class of micro-scale antibody constructs engineered for targeted binding in biomedical research and clinical applications. These molecules are designed to retain antigen specificity while being smaller than conventional antibodies, typically under 100 kilodaltons. Common formats within microAB include nanobodies (single-domain antibodies), single-chain variable fragments (scFv), and other mini-antibodies built from modular antibody domains.

Generation and formats rely on recombinant expression in systems such as bacteria, yeast, or mammalian cells, followed by purification and quality control. MicroAB constructs can be deployed as monovalent agents or assembled into multivalent or multispecific formats to increase avidity or enable dual targeting. They can also be conjugated to imaging probes, cytotoxic drugs, radionuclides, or fluorescent labels for diagnostic and therapeutic applications.

Applications of microAB span molecular imaging, targeted drug delivery, radioligand therapy, and fluorescence-guided surgery. Their small size can enhance penetration into tissues and tumors and allow rapid clearance from non-target sites, improving signal-to-background in imaging and reducing systemic exposure in some therapeutic contexts. However, their reduced size often leads to shorter serum half-life and potential renal filtration, and immunogenicity or stability issues can arise depending on the source and modifications.

Manufacturing considerations include recombinant production, stringent characterization of binding specificity, stability, and pharmacokinetics, and adherence to regulatory requirements for biologics. Ongoing research explores half-life extension strategies, multispecific designs, and integration with imaging or therapeutic modalities to broaden clinical utility. See also: antibody fragments, nanobodies, scFv, and mini-antibodies.