Dynamic Polymers portfolio

P03393US: Charge-Dynamic Polymers for Delivering Anionic Compounds, Such as DNA, into Cells

Overview: The safe and efficient delivery of DNA into cells is essential for the clinical success of gene therapy. Synthetic polymers are considered long-term alternatives to virus-based gene delivery agents because they exhibit low immunogenicities and can be easily modified. Of particular interest are cationic polymers. These molecules spontaneously self-assemble with anionic DNA to form condensed interpolyelectrolyte complexes (IPECs) that cells can efficiently internalize. However, once inside the cell, conventional cationic polymers cannot dissociate readily or promote the release of bound DNA.

The Invention: UW-Madison researchers have developed polymers that allow temporal control over the dissociation of DNA from polymer/DNA interpolyelectrolyte complexes. The cationic polymers undergo dynamic changes in charge states (from cationic to less cationic) to trigger the “unpackaging” of anionic molecules from IPECs. The polymers possess cationic charge densities that result from the number, type, and position of functional groups attached to the backbone; specifically, cationic charge densities decrease when one or more of the functional groups is removed.

In one embodiment, side chain esters are introduced to linear poly(ethylene imine) (PEI) via conjugate addition chemistry. The PEI is then complexed with an anionic molecule such as DNA. When the pendant ester groups are hydrolyzed, the cationic charge density of the polymer is reduced, promoting the dissociation of the polymer/DNA complex and efficient release of DNA.

Applications

• Can potentially deliver polynucleotides, proteins, small molecules, antigens or drugs to a patient
• Provides controlled, sustained release of an encapsulated agent
• Allows the initial formation of polymer/DNA complexes and later facilitates the efficient and timely unpackaging of DNA in the intracellular environment

Key Benefits

• Would allow more complete utilization of existing technologies that address other barriers to gene delivery
• Can be designed so the charge shift of the polymer occurs on a desired time scale
• Cell/tissue delivery can be in vivo or in vitro

P07251: Multilayered Film for Delivering Proteins and Other Small Molecules into Cells

Overview: The ability to deliver proteins into cells has many therapeutic and research applications. However, peptide drugs and therapeutic proteins are notoriously difficult to administer, in part because of the limited permeability and selectivity of the cell membrane.

Polyelectrolyte multilayers (PEMs) have been used to deliver biomolecules into cells. PEMs are essentially thin plastic films with alternating layers of positively and negatively charged polymers. Biomolecules, such as nucleic acids, can be integrated into PEMs, which can be designed to dissolve under physiologically relevant conditions to release the biomolecules into cells.

Previous attempts to use these films to deliver proteins focused mainly on naturally occurring, wild-type proteins. However, this approach is limited because the assembly conditions and film properties are dependent on the charge, isoelectric point and other properties of the proteins and polyelectrolytes used. Many wild-type proteins cannot successfully be integrated into PEMs.

The Invention: UW-Madison researchers have developed a new way of delivering proteins and other small molecules into cells. This approach uses a cationic “anchor” to improve incorporation of proteins into multilayered films.

Before the protein or small molecule is integrated into the film, a cationic protein transduction domain, such as nonaarginine, is attached to it. Appending short, cationic peptides or oligomers to proteins can facilitate their layer-by-layer assembly into PEMs, as well as their uptake by cells.

Then the cationic molecule is incorporated into a polyelectrolyte multilayered film, along with anionic polymers such as sodium polystyrene sulfonate, to result in a multilayered assembly that is preferably about 80 nanometers thick. When this composition is presented to a cell, the film dissolves, delivering the molecule to the cell.

Applications:

• Delivering active proteins and other biomolecules, including nucleic acids, drugs, toxins, carbohydrates or metabolites, into cells
• Coating medical devices to provide for the localized release of therapeutics
• Coating disposable research tools, such as pipette tips, tubes and petri dishes

Key Benefits:

• Enables the efficient and localized delivery of functional proteins and other biomolecules, including nucleic acids, drugs, toxins, carbohydrates or metabolites, into cells
• Attaching cationic protein transduction domains to proteins provides a straightforward method for conferring cationic charge without compromising protein function, enabling the incorporation of proteins into multilayered films under conditions for which unmodified, wild-type proteins cannot be used.
• Provides a method of controlling the speed at which protein is released
• Promotes the efficient uptake of protein from the surfaces of coated objects, including implanted materials, medical devices and disposable research tools
• Multilayered films are capable of dissolving in physiological media.
• A molecular linker may be attached to the protein transduction domain to attach other molecules for import into cells.

P08389: Novel Charge Shifting Anionic Polymers for the Controlled Release of Cationic Agents from Surfaces

Overview: The ability to deliver biomolecules, such as proteins or nucleic acids, into cells has many therapeutic and research applications. Polyelectrolyte multilayers (PEMs) have been used to deliver biomolecules into cells. PEMs essentially are thin plastic films with alternating layers of negatively charged (anionic) and positively charged (cationic) polymeric coatings. Biomolecules, such as nucleic acids, can be integrated into PEMs, which can be designed to controllably dissolve under physiologically relevant conditions to release the biomolecules into cells.

UW-Madison researchers previously developed novel charge shifting cationic polymers that can be incorporated into PEMs for the delivery of nucleic acids and other polyanions (see WARF reference number P03393US). These polymers can be used to create medical devices and research agents that provide greater control and efficiency of nucleic acid delivery into cells.

The Invention: UW-Madison researchers now have developed novel compositions and methods for creating charge shifting anionic polymers. These polymers could be used to create polymeric multilayers and thin films that can controllably release cationic agents such as proteins and peptides.

The anionic polymers are prepared by the reaction of small-molecule anhydrides, such as citraconic anhydride, with primary amine side chains on a polymer backbone, such as poly(allylamine hydrochloride), a weak polyelectrolyte widely used for the fabrication of polyelectrolyte multilayers. This reaction yields an anionic, carboxylate-functionalized polymer that can undergo a dynamic change in charge state (from anionic to less anionic) to trigger the “unpackaging” of cationic molecules.

Applications:

• Thin films and coatings that enable the controlled release of cationic agents, such as therapeutic proteins, from the surfaces of macroscopic, microscopic or nanoscopic objects
• Drug delivery

Key Benefits:

• May be used to create PEMs that remain stable at near-neutral pH but erode and release incorporated cationic molecules when exposed to acidic environments
• Enables control over film erosion and the release of cationic agents
• Synthetic polymers are anionic and may be degradable.
• May be non-immunogenic, non-toxic or both
• Also may be biodegradable and biocompatible
• Ligands that facilitate the delivery of the polymer to a specific target may be included.

Included IP

• P0339US (PAT)
• P07251US (PAT)
• P08389US (PAT)
• P08389US02 (DIV)