Immunoliposomes

• Amine Reactive Liposomes

• Azide Reactive Liposomes

• Biotinylated Liposomes

• Carboxylic Acid Reactive Liposomes

• DBCO Reactive Liposomes

• Folate Liposomes

• Metal Chelating Liposomes

• Sulfhydryl Reactive Liposomes

BOC Sciences develops a variety of immunoliposomes for use in areas such as tumor therapy, inflammation therapy, and vaccine delivery.

What are Immunoliposomes?

Immunoliposomes are liposomes on which antibodies are attached to the surface of the liposome to recognize the target cells and enhance the targeting of the liposome. For example, monoclonal antibody 3G against gastric cancer cell surface antigen was conjugated to mitomycin (MMC) liposome to make immunoliposome, and in vivo, the immunoliposome had 4-fold higher M85 killing effect on gastric cancer target cells than free MMC.

Fig 1. Immunoliposome formation. (Parveen et al., 2022)

Development of Immunoliposomes

• First generation immunoliposomes (IML)

The first generation IML are liposomes with monoclonal antibodies attached. Through the specific binding of monoclonal antibodies to target cells, the liposome-encapsulated drug is directed to the target tissue, giving the liposome active targeting properties.

• Second generation immunoliposomes

Second-generation IML includes PEG-containing, long-circulating liposomes that enable binding of antibodies or ligands to the liposome surface.

• Third generation immunoliposomes

In order to increase the targeting properties of long-lived liposomes, a new type of liposome is obtained by attaching antibodies or other ligands to the ends of polymer (e.g., PEG) chains on the surface of the long-lived liposome, thus avoiding the interference of the PEG chains with the recognition of the target site.

Immunoliposomes Product Types

• Amine Reactive Liposomes

Amine reactive liposomes are functionalized liposomes whose molecules or portions can react with amine groups to facilitate binding reactions with amine-containing biomolecules such as proteins, peptides, and antibodies, and are important precursors for the preparation of immunoliposomes.

• Azide Reactive Liposomes

Azide reactive liposomes can react with other molecules or compounds having complementary reactive groups, such as alkyne groups (-C = CH), to form covalent bonds via copper-free click chemistry.

• Biotinylated Liposomes

Biotinylated liposomes have a biotinylated portion and are primarily used for coupling to proteins or biotinylates (e.g., antibodies) with affinity (streptavidin).

• Carboxylic Acid Reactive Liposomes

Carboxylic acid reactive liposomes are a special type of liposomal nanocarrier designed to selectively interact with molecules or surfaces containing carboxylic acid groups.

• DBCO Reactive Liposomes

DBCO reactive liposomes can be used to deliver a wide range of payloads including chemotherapeutic agents, probes, siRNAs, aptamers, antibodies, etc.

• Folate Liposomes

Folate liposomes can be synthesized by utilizing the carboxyl group of folic acid to react with complementary reactive groups of lipids, cholesterol and proteins.

• Metal Chelating Liposomes

Metal chelating liposomes are a special class of liposomes that contain a metal chelating agent as well as appropriate lipid components.

• Sulfhydryl Reactive Liposomes

Sulfhydryl reactive liposomes contain groups that react with sulfhydryl (thiol) groups to link molecules containing sulfhydryl or thiol groups.

Characteristics of Immunoliposomes

• Immunoliposomes are modified with specific antigenic antibodies or antibody fragments on their surface, allowing selective recognition and targeted delivery against specific cells or tissues.
• Liposomes have good drug carrier properties and can encapsulate a variety of water-soluble and fat-soluble drugs.
• Immunoliposomes can deliver drugs to tumor cells, inflammatory sites, or other antigens expressed on the surface of specific cells through the specific recognition of antigens and antibodies.
• Immunoliposomes can carry not only chemical drugs, but also carrier genes, nucleic acids and other biologically active substances.

Applications of Immunoliposomes

• Tumor therapy

Through surface modification of antibodies or antibody fragments specific to tumor antigens, immunoliposomes are able to target tumor cells and release drugs, genes or other therapeutic substances to achieve targeted tumor therapy.

• Inflammation therapy

It can be used to treat various inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease.

• Vaccine delivery

Immunoliposomes can mimic pathogens and activate the immune system to generate specific immune responses.

• Diagnostic imaging

Immunoliposomes can be used for targeted imaging of specific cells or tissues by combining markers such as fluorescent dyes, radioisotopes or magnetic resonance contrast agents with immunoliposomes.

Reference

1. Parveen N, et al. Immunoliposomes as an emerging nanocarrier for breast cancer therapy[J]. European Polymer Journal, 2022: 111781.