Title:  Process of making a compound by forming a polymer from a template drug

United States Patent:  6,126,964

Inventors:  Wolff; Jon A. (Madison, WI); Hagstrom; James E. (Madison, WI); Budker; Vladimir G. (Madison, WI); Trubetskoy; Vladimir S. (Madison, WI); Slattum; Paul M. (Madison, WI); Hanson; Lisa J. (Madison, WI)

Appl. No.:  778657

A method of forming polymers in the presence of nucleic acid using template polymerization. Also, a method of having the polymerization occur in heterophase systems. These methods can be used for the delivery of nucleic acids, for condensing the nucleic acid, for forming nucleic acid binding polymers, for forming supramolecular complexes containing nucleic acid and polymer, and for forming an interpolyelectrolyte complex.

SUMMARY OF INVENTION

A process for drug delivery is described in which polymerization and chemical reaction processes are induced in the presence of the drug in order to deliver the drug or biologically active compound. Drug delivery encompasses the delivery of a biologically active compound to a cell. A biologically active compound is a compound having the potential to react with biological components. Pharmaceuticals, proteins, peptides and nucleic acids are examples of biologically active compounds. The template polymer can be a polyanion such as a nucleic acid. The polynucleotide could be used to produce a change in a cell that can be therapeutic. The delivery of polynucleotides or genetic material for therapeutic purposes is commonly called "gene therapy".

A new method is described for forming condensed nucleic acid by having a chemical reaction take place in the presence of the nucleic acid. A process is also described of forming in the presence of the nucleic acid a polymer that has affinity to nucleic acid. Moreover, a process is described of forming an interpolyelectrolyte complex containing nucleic acids by having a chemical reaction take place in the presence of the nucleic acid. In addition, the nucleic acid-binding polymer can form as a result of template polymerization. This obviously excludes the formation of polymers such as proteins or nucleic acids or other derivatives that bind nucleic acid by Watson-Crick binding.

Previously, the occurrence of chemical reactions or the process of polymerization in the presence of the nucleic acid has been assiduously avoided when delivering nucleic acid. Perhaps, this arose out of concerns that the processes of chemical reactions or polymerization would chemically modify the nucleic acid and thereby render it not biologically active. Surprisingly, we show that we can perform polymerizations in the presence of nucleic acids without chemically modifying the nucleic acid and that the nucleic acid is still functional. For example, a plasmid construct containing a promoter and the reporter gene luciferase can still express as much luciferase as native plasmid after transfection into cells.

The process of forming a polymer in the presence of nucleic acid has several advantages. As FIG. 1 illustrates, aggregation and precipitation of the nucleic acid can be avoided by having the polymerization take place in the presence of the nucleic acid. This newly described process enabled us to form supramolecular complexes of nucleic acid and polymer rapidly, consistently, and at very high concentrations of polynucleic acid. In fact, high concentration of the template nucleic acid favors this process. In contrast, the previously described process of mixing a nucleic acid and an already-formed polycation (such as polylysine) has to be done at very dilute concentrations. In addition, the previously-described procedure requires that the mixing, salt and ionicity conditions must be carefully controlled as well. This explains why the use of polylysine-DNA complexes are not widely used for the transfer of DNA into cells and is only done in a few laboratories.

The other advantage that flows from the newly described process of having polymerization take place in the presence of nucleic acid is that polymers could form that would not be able to become associated with nucleic acids if the polymer was formed first. For example, the polymerization process could result in a hydrophobic polymer that is not soluble in aqueous solutions unless it is associated with nucleic acid. Furthermore, the process of having the polymerization taking place in organic solvents and heterophase systems enables more types and more defined types of vesicles to be formed.

This process will enable supramolecular complexes to be more easily assembled. It will also enable novel and more defined complexes to be made. Yet another advantage that flows from this invention is that nucleic acid/polymer complexes will be smaller. The size of DNA/polymer complex is critical for gene delivery especially in vivo.

These processes can be used for transferring nucleic acids into cells or an organism such as for drug delivery. They may also be used for analytical methods or the construction of new materials. They may also be used for preparative methods such as in the purification of nucleic acids. They are also useful for many types of recombinant DNA technology. For example, they may be used to generate sequence binding molecules and protect specific sequences from nuclease digestion. Protection of specific regions of DNA is useful in many applications for recombinant DNA technology.

Claim 1 of 11 Claims

We claim:

1. A method of making a complex for delivery to a cell, comprising: covalently forming a polymer, from monomers, in the presence of a polyion, wherein the polymer is formed outside of any cell, resulting in a polymer-polyion complex for delivery to a cell, wherein the polyion is not removed from the complex prior to administration.

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.