LSU Professor receives patent for hydrophobically modified polypeptoids designed for drug delivery and imaging agents

LSU Chemistry | November 2, 2021


schematic of the formation of mulitple-bilayer liposomesFigure 1. (a) Schematic of the formation of multiple-bilayer liposomes and the solubilization of liposomes induced by HMP. (The scale bars in all images are 50 nm.) (b) Illustration of HMP bridging the fragments and the lipid bilayer of a liposome by hydrophobe insertion forming a two-bilayer structure.  [Reprinted with permission from Zhang, Y.; Xuan, S.; Owoseni, O.; Omarova, M.; Li, X.; Saito, M.; He, J.; McPherson, G.; Raghavan, S.; Zhang, D.; John, V. Amphiphilic Polypeptoids Serve as the Connective Glue to Transform Liposomes into Multilamellar Structures with Closely Spaced Bilayers. Langmuir 2017, 33, 2780-2789. Copyright 2017 American Chemical Society.]

BATON ROUGE, LA- Due to their ability to be recognized by both water and lipids in the human body, liposomes are efficient and effective vehicles for various compounds, including drugs, diagnostic agents, and skincare products. These nano-sized vesicles are comprised of one or more lipid bilayers with aqueous internal compartments. 

For an effective delivery system, water-soluble compounds are enclosed in internal aqueous spaces. Hydrophobic compounds that are poorly water-soluble can be incorporated into the lipid bilayers, which creates disadvantages. 

“Incorporating hydrophobic compounds into a lipid bilayer limits the quantity of compounds that can be delivered. The liposome structure itself can become unstable,” said LSU Chemistry Professor Donghui Zhang. “Hydrophobically modified polypeptoids, on the other hand, have promising applications related to hydrophobic drug encapsulation and delivery.”

Professor Zhang, Chemical and Biomolecular Engineering Professor Vijay John (Tulane University), and graduate students Yueheng Zhang (Tulane University) and Sunting Xuan (LSU) recently received a patent (Patent No: US 11,123,433 B2) for various hydrophobically modified polypeptoids (HMPs), their synthetic methods, and applications for liposomal drug delivery. 

These chemically synthesized polypeptoids are biocompatible and demonstrate numerous interesting properties and effective applications, including antimicrobial compositions. For example, at low concentrations, HMPs can be used to break down lipid bilayers into small segments and attach them to other lipid bilayers or to other liposomes.  They can also be broken down into smaller parts, called lipid-polypeptoid rafts, allowing the encapsulation and delivery of one or more hydrophobic drugs. 

“HMP can be considered as macromolecular surfactants with many hydrophobic arms. They can interact with cellular membranes to enable cargo transport into the cell interior, and also induce the structural remodeling of cellular membrane causing cell death, which all depends on the formulation. The application of HMP will mainly be in the area of targeted delivery of drugs or imaging agents,” Zhang said. 

To learn more about the Zhang research group and their work on the design, synthesis, and characterization of biomimetic, bioinspired, and bio-derived functional polymers, visit their group page



Media Contact:
Gretchen Schneider
LSU Chemistry