Patent Title: Polymerized liposomes targeted to M cells and useful for oral or mucosal drug delivery
Inventors and Affiliation – Hongming Chen (Director of Formulation, Transform Pharmaceuticals), Robert S Langer (Institute Professor, MIT).
Key Words- Liposome, polymerized, lectin, vaccine, targeted delivery
The main focus of the patent
The patent describes a method to make micro vesicles called liposomes that are used to encapsulate drugs and vaccines for uptake by cells. Previously developed liposomes had to be administered by injection since they were destroyed by the harsh environment in the gastric tract when given orally. However the liposomes described in this patent have been chemically modified (by polymerization) to make the coating strong enough resist destruction by the gastric acid and intestinal enzymes. Additionally, carbohydrate molecules called lectins have been attached on their surface that help them bind to and be taken up by specific immune cells in the intestine. As a result, these vesicles can be designed to contain different vaccines, allergens and drugs and given orally without destruction and leakage of the agents before they reach and concentrate at the site of intended action.
Limited technical details
The drug delivery system patented comprises mainly of 3 components.
- At the core is a drug or vaccine (in which case it comprises of an antigen to evoke the immune response and an adjuvant to facilitate it). These are typically hydrophobic and need to be encapsulated in a lipid bilayer in order to be taken up by cells.
- The core is encapsulated in an envelope that has phospholipid molecules covalently bonded to each other at varying degrees thereby increasing its ability to withstand destruction by gastric acid and intestinal enzymes.
- The targeting molecule may be, for example, a carbohydrate (lectin) attached to the surface of the capsule that is recognized and bound by specific cells (in this case immune cells in the Peyer’s patch of the intestine) thereby facilitating the uptake of these vesicles by them. Other targeting molecules can include various carbohydrates, monoclonal antibodies, antibody fragments, viral proteins, bacterial proteins and magnetic particles.
Implications/applications and sectors that are addressed by patent/technology
This technology offers a drug delivery system to target specific cell or organs as intact particles where they can release the drug/antigen after uptake by the cells. Based on a variety of agents that can serve as the core (different drugs, vaccines, antigens etc) and the possible modifications on the surface to target various cells or tissues, a wide variety of applications can be approached with this patent. It will be specifically useful in offering orally or mucosally administrable alternatives in conditions where the agent needs to bypass gastric and intestinal destruction and targeted to specific cells. The patent describes the delivery of a wide variety of compounds, allergens and antigens, including, but not limited to insulin peptides, diphtheria toxin antigens and influenza antigens as well as chemotherapy agents for the treatment of cancer; cytokines, including interferon; and hormones including insulin, human growth hormone (HGH), fertility drugs, calcitonin, calcitriol and other bioactive steroids.
History of the Inventors:
Hongming Chen: Chen was involved in founding TransForm Pharmaceuticals, a company engaged in the development of pharmaceutical products and based in Lexington, MA in 1999. Chen is currently the director of formulation development at Transform (which is now a subsidiary of the Johnson & Johnson group of companies).
Robert Langer: Langer is an extremely successful inventor and holds more than 600 granted or pending patents. He has been involved in the creation of about 25 companies and serves as a director on the boards of Echo Therapeutics, Inc., a medical device and pharmaceutical company, Momenta Pharmaceuticals, Inc., a biotechnology company developing drugs based on sugar sequencing technology, Alseres, Inc., a company focused on research and development of therapeutic and diagnostic products, and Wyeth, a pharmaceutical and consumer healthcare products company.
Similar Patents
US Patent Application 20090162424: Compositions and methods for making and using multifunctional polymerized liposomes
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US Patent 6350466: Targeted polymerized liposome diagnostic and treatment agents
Patentgo’s opinion:
Liposomes which are microscopic phospholipid bubbles are an innovative form of drug delivery to administer a wide range of drugs and vaccines that would otherwise be easily degraded in the blood. There is an attraction in developing orally administrable forms of liposomes that resist the gastric acid to avoid the necessity of parenteral administration. The current invention not only offers resistance to gastric acid, but also combines a targeting molecule to selectively concentrate the drug at specific cell types. However the applications tried by the inventors have only been partially successful and they need to explore alternate applications since the model of combining the liposome with different drugs in the core and targeting molecules on the surface offers a lot of possibilities. Simultaneously they would have to compete with alternate technologies such as chitosan coated liposomes, ganglioside containing liposomes and PEG coated liposomal preparations that are also designed for oral liposome delivery.
