As a leading CRO, BOC Sciences is dedicated to providing custom conjugation services. We are able to provide antibody-liposome conjugation services to meet your unique project needs.
Antibody-targeted liposomes are also known as immunoliposomes (immunoliposomes, ILs). It has the ability to recognize target cells at the molecular level and effectively kill the diseased cells. As a new type of drug delivery system, immunoliposomes have the advantages of both liposomes and targeted antibodies, reducing the accumulation of drugs in normal tissues, increasing efficacy and reducing toxicity. Immunoliposomes can be used as carriers of tumor chemotherapy drugs, radiotherapy drugs, gene therapy drugs and tumor imaging diagnostic agents, and can be applied for targeted therapy and detection of tumors, showing broad application prospects in tumor clinical treatment and diagnosis.
There are many targeting molecules linked to liposomes, including antibodies, antibody fragments, small molecule polypeptides, glycoproteins or receptor ligands. The targeting antibodies of immunoliposomes can be monoclonal antibodies (mAbs), antibody Fab fragments and single-chain antibodies (scFv), etc. Factors such as ability to mediate adipocyte action, immunogenicity, stability, and purification should be considered when selecting antibodies.
There are various methods for binding antibodies or fragments thereof to liposomes, among which the chemical coupling method through reactive functional groups is the most commonly used. Antibodies can be directly linked with lipid materials such as phospholipids by using their own functional groups or by cross-linking agents with active groups. Phospholipid materials can be attached to antibodies directly by using functionalized phospholipid derivatives or cross-linking agents with active groups.
The formation of thioether bonds between ligands and liposomes is a common coupling method. The maleimide group at the end of the phospholipid-derived material is usually attached to the thiolated antibody to form a thioether linkage. Moreover, thioether linkages can be generated by reducing the pyridinedisulfide propylamide (PDP) of phospholipid-derived materials to generate free sulfhydryl groups, which are then attached to antibodies that introduce maleimide groups via thioether linkages. Disulfide coupling is typically accomplished by attaching a PDP-containing phospholipid-derived material to a thiolated antibody, followed by removal of the 2-thiopyridone to form a disulfide bond.
As the carrier of tumor chemotherapeutic drugs, immunoliposomes can encapsulate chemotherapeutic drugs and transport them to corresponding tissues or organs, so that they accumulate in tumor cells, improve the selectivity of tumor cells, and reduce toxic and side effects. Immunoliposomes smaller than 200 nm can aggregate within the tumor stroma with enhanced osmotic retention and allow the drug to be widely distributed in tumor tissue. In addition, receptor-mediated endocytosis of liposomes can significantly increase the concentration of drugs in tumor cells.
Immunoliposomes play a role as carriers of radiotherapy drugs and imaging agents. When immunoliposomes are linked or encapsulated with imaging agents, tumor tissue can be targeted at the cellular or subcellular level to monitor tumor lesions and therapeutic effects at the molecular level.
Immunoliposomes can be used as carriers of gene drugs. Positively charged cationic liposomes can form liposome complexes with negatively charged DNA or RNA through electrostatic interactions, enhancing their capillary permeability at tumor sites. Immunoliposomes have gradually been widely used in gene therapy due to their good stability, strong targeting and high transfection efficiency.