Lead Inventor: Ponisseril Somasundaran, PhD.

Problem or Unmet Need:
Nanoparticles continue to find an ever-increasing number of uses in industry and medicine. One such use is for the controlled-delivery and/or extraction of bioactive molecules at specific sites both in vivo and in vitro. In general, nanoparticles may be constructed from either naturally-occurring or synthetic polymers, which must be crosslinked to form spherical nanoparticle structures capable of carrying molecules. The most prevalent way of crosslinking nanoparticle polymers is via reverse microemulsion methods using toxic ammonium persulfate as a catalyst. In order to synthesize nanoparticles fit for biological use, non-toxic crosslinking methods must be found.

Details of the Invention:
This invention describes a technique for crosslinking polymers using gamma radiation that renders poly(acrylic acid) nanoparticles (PAANPs) safe for in vivo use. Poly(acrylic acid) nanoparticles are formed by adding poly(acrylic acid) or hydrophobically-modified poly(acrylic acid) to a solution of hexane and a polysorbate. After nitrogen is passed through the mixture, the polymers are exposed to gamma radiation, causing them to crosslink into a polymeric nanoparticle. The nanoparticles are then precipitated out of solution using an organic solvent. Fragrance molecules such as linylacetate, for example, may be inserted into the nanoparticles by immersing the PAANPs in the fragrance and stirring for some time.

Applications:
-- Controllable release of fragrances, such as vanillin or linylacetate
-- Delivery and slow-release of pharmaceuticals, small molecules, and bioactive agents such as antimocrobials, antibiotics, antitoxins, antibodies, and proteins
-- Removal of drugs from the blood stream using nucleic acid aptamers with high affinity for targeted molecules

Advantages:
-- PAANPs are formed using gamma radiation, as opposed to significantly more toxic chemical means, as a catalyst for polymerization
-- Nanoparticles and nanogels may be engineered to carry a wide-variety of molecules, including hydrophobic, hydrophilic, and ionic substances
-- The nanoparticles are water dispersible
-- This technology allows for the controlled release of substances over a long period of time


Patent Status: Patent Pending (WO2006052285-A2, US2008260851-A1) ~ see links below.

Licensing Status: Available for Sponsored Research Support

Publications: Chakraborty, S. and P. Somasundaran. "Sequestration of drugs using poly(acrylic acid) and alkyl modified poly(acrylic acid) nanoparticles." Soft Matter. 2: 850-854 (2006).

Other Links:

• WIPO - WO/2006/052285
• USPTO - US20080260851A1

Further Information
Beth Kauderer
212.854.4941
Email: TechTransfer@columbia.edu

File Number: M04-040