Targeted Liposome Development Service

A majority of drugs used for severe diseases such as cancer are cytotoxic molecules, which may distribute within the whole body and result in toxicity to normal tissues after administration. Liposomes have been recognized as a desirable drug carrier to increase the interaction or distribution between drugs and diseased tissues early in the history of its development. As a professional drug carrier provider with extensive experience in pharmaceutical and cancer research, Creative Biolabs is guaranteed to formulate the targeted liposome with the most suitable ligand according to your requirements.

Introduction to Targeted Liposomes

Passive targeting and active targeting are the two strategies for targeted liposomes. Liposomes with a specific size range of 100 to 200 nm can accumulate into the tumor interstitial space due to EPR (enhanced permeability and retention) effect, which is defined as passive targeting. Drug-loaded liposomes with this property have been clinically proved to have antitumor activity. Moreover, the ligand-mediated targeting, which is active targeting strategy, could achieve an additional level of sophistication and specificity over desired cells & tissues through selective cellular binding and ligand-receptor mediated endocytosis, and result in enhanced efficacy and reduced systemic toxicity. The targeting ligands include monoclonal antibodies, antibody fragments (fragment antigen-binding (Fab), single-chain variable fragment (scFv)), proteins, peptides, vitamins, carbohydrates, glycoproteins, and any other molecule that can target receptors overexpressed on the surface of particular cells.

Fig 1. Structure and endocytosis of targeted liposomes

Applications of Targeted Liposomes

Targeted liposomes could help accumulate in different tissues or bind to cells according to the ligands, such as liver, kidney, white adipose tissue (WAT), blood-brain barrier (BBB), and tumor tissue. An ideal target receptor or antigen should be highly expressed in target tissues but have low expression in other tissues. For example, human epidermal growth factor receptor 2 (HER2) is overexpressed 1000-fold higher in about 25% of breast cancer cases than that of normal tissue, making it a common target with positive preclinical results in targeted cancer therapy.

Ligand selection is of equal importance in the development of targeted liposomes. Antibodies or antibody fragments (Fab/scFv) are the most commonly used targeting ligands owing to their high affinity and specificity. To be more precise, antibodies are more used in the early research while antibody fragments are updated versions with reduced immunogenicity and improved pharmacokinetics profiles. In recent years, advancements in phage display libraries have enabled numerous novel peptides to be potential targeting ligands, which also possess the advantages of lower cost, lower antigenicity, and increased resistance to enzymatic degradation. Additionally, other types of ligands have also been used in various targeted liposomes (in Table 1). For example, vitamins and sugar can be recognized by the corresponding cellular transporter receptors, and transferrin can target the transferrin receptor.

Table 1 Receptors and ligands for targeted liposomes

What We Can Do about Targeted Liposome Development?

Targeted liposomes can be surface modified to enhance selective targeting and facilitate intracellular uptake after administration. The first-generation liposomes were mainly focused on reducing systemic toxicity, and now more efforts are made for a better understanding of in vivo behaviors of targeted liposomes, as well as optimization of liposome design. Creative Biolabs provides one-stop targeted liposomes development service relying on our experienced liposome research, including:

• Targeting ligands selection & design
• Liposome formulation optimization
• Liposome characterization & related tests
• Liposome manufacturing schemes
• Experimental consultation

Please feel free to contact us for more details about our service.

For Research Use Only. Not For Clinical Use