News Column

Patent Issued for Composition for Nucleic Acid Delivery Using Metal Nanoparticles and Preparing Method

June 26, 2014



By a News Reporter-Staff News Editor at Gene Therapy Weekly -- From Alexandria, Virginia, NewsRx journalists report that a patent by the inventors Hahn, Sei Kwang (Pohang, KR); Lee, Min-Young (Pohang, KR); Park, Kitae (Jeonju, KR); Kim, Ki Su (Pohang, KR); Lee, Hwiwon (Daegu, KR), filed on March 27, 2012, was published online on June 10, 2014 (see also Postech Academy-Industry Foundation).

The patent's assignee for patent number 8747903 is Postech Academy-Industry Foundation (Pohang, KR).

News editors obtained the following quote from the background information supplied by the inventors: "(a) Field of the Invention

"The present invention relates to a composition for nucleic acid delivery and a method for preparing the same, more particularly to a composition for nucleic acid delivery, which has excellent stability in the body environment and excellent intracellular nucleic acid delivery efficiency, and is capable of target directed delivery of nucleic acid, and a method for preparing the same.

"(b) Description of the Related Art

"Recently, industrial importances of small interfering ribonucleic acid (siRNA), antisense oligonucleic acids, plasmid deoxyribonucleic acid, and the like as nucleic acid-based drugs are highlighted. However, to develop nucleic acids as drugs, efficient delivery to cells or tissues should be solved first.

"For intracellular delivery of nucleic acids, studies on viral vectors or non-viral vectors using polymer or nanoparticles are under progress. Among them, a viral vector has higher gene delivery efficiency than a non-viral vector, but its application to humans is very limited due to safety problem of using virus. Thus, development of non-viral vectors as a safer alternative to viral vectors is under progress.

"Currently, cationic liposome, TAT peptide, or cationic polymer such as polyethylenimine (PEI) is largely used as delivery system for nucleic acid, particularly siRNA. Particularly, it has been reported that cationic polymer of polyethyleneimine (PEI) compresses negatively charged nucleic acids to form colloidal particles, and holds pH buffering capacity even in lysosome in the cells, and thus, delivers plasmid deoxyribonucleic acids to various cells (Boussif et al., Proc. Natl. Acad. Sci. USA 92 (1995) 7297-7301; Godbey et al., J. Controlled Release 60 (1999)149-160).

"However, it was found that the cationic polymer causes cell aggregation in the body and binds electrostatically to blood protein to lower siRNA activity, and causes fatal toxicity to body organs such as liver, lung, and the like. Thus, it is known that the cationic polymer is difficult to be utilized alone as siRNA delivery system. And, regarding the use of polyethyleneimine, there are remaining problems relating to intracellular gene delivery efficiency and cytotoxicity, and thus, many studies for solving these problems are under progress. For example, to reduce cytotoxicity of polyethyleneimine (PEI), a method of modification with dextran sulfate, human serum albumin, polyethylene glycol, and the like has been attempted, but the modified PEIs commonly exhibited lower gene delivery efficiency than PEI itself.

"Accordingly, there is a need for technology of efficient intracellular delivery of small interfering ribonucleic acid, oligonucleic acid such as antisense oligonucleic acid, and the like, having excellent stability in the body.

"Meanwhile, gold nanoparticles are known to have excellent biocompatibility, and the particle size may be controlled and the surface modification is easy, and thus, many studies on binding biomolecules to them are under progress. And, hyaluronic acid is linear polymer polysaccharide consisting of alternating .beta.-D-N-acetylglucosamine and .beta.-D-glucuronic acid, it does not have species- and organ-specificity, and it is known to exhibit excellent biocompatibility even when implanted or injected in the body."

As a supplement to the background information on this patent, NewsRx correspondents also obtained the inventors' summary information for this patent: "In order to overcome the problems of the prior art, it is an object of the present invention to provide a composition for nucleic acid delivery having excellent stability in the body environment and excellent intracellular nucleic acid delivery efficiency, and capable of target directed delivery of nucleic acid, a method for preparing the same, and a method for delivering nucleic acid using the composition for nucleic acid delivery.

"To achieve the object, as results of studies on technology relating to nucleic acid delivery system having excellent stability in the body and capable of efficiently delivering nucleic acid in the cell, the inventors confirmed that when a polymer self assembled composite that is prepared by sequentially coating nucleic acid, cationic polymer, and anionic polymer on metal nanoparticles by electrostatic layer by layer self assembly so as to protect nucleic acid from the external environment is used as intracellular nucleic acid delivery system, nucleic acid stability in the body and intracellular nucleic acid delivery efficiency may be remarkably improved, and completed the invention.

"Therefore, according to one embodiment of the invention, there is provided a composition for nucleic acid delivery comprising positively charged metal nanoparticles; and a nucleic acid layer, a cationic polymer layer and an anionic polymer layer, formed by coating of nucleic acid, cationic polymer and anionic polymer on the surface of the metal nanoparticles by electrostatic layer by layer self assembly.

"According to another embodiment of the invention, there is provided a method for preparing a composition for nucleic acid delivery, comprising: reacting metal nanoparticles with positive charge introducing material to introduce positive charge on the surface of the metal nanoparticles; coating nucleic acid on the surface of the positive charge introduced metal nanoparticle surface to form a metal nanoparticle/nucleic acid composite; coating cationic polymer on the metal nanoparticle/nucleic acid composite to form a metal nanoparticle/nucleic acid/cationic polymer composite; and coating anionic polymer on the metal nanoparticle/nucleic acid/cationic polymer composite to form a metal nanoparticle/nucleic acid/cationic polymer/anionic polymer composite, wherein the nucleic acid, cationic polymer, and anionic polymer is coated by electrostatic layer by layer self assembly.

"According to yet another embodiment, there is provided a method for delivering nucleic acid using a composition for nucleic acid delivery comprising positively charged metal nanoparticles; and a nucleic acid layer, a cationic polymer layer and an anionic polymer layer, formed by coating of nucleic acid, cationic polymer and anionic polymer on the surface of the metal nanoparticles by electrostatic layer by layer self assembly."

For additional information on this patent, see: Hahn, Sei Kwang; Lee, Min-Young; Park, Kitae; Kim, Ki Su; Lee, Hwiwon. Composition for Nucleic Acid Delivery Using Metal Nanoparticles and Preparing Method. U.S. Patent Number 8747903, filed March 27, 2012, and published online on June 10, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8747903.PN.&OS=PN/8747903RS=PN/8747903

Keywords for this news article include: Biotechnology, Viral, Virus, Gene Therapy, Nanoparticle, Bioengineering, Nanotechnology, Emerging Technologies, Postech Academy-Industry Foundation.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Gene Therapy Weekly


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters