News Column

Patent Issued for Modular Functional Peptides for the Intracellular Delivery of Nanoparticles

August 19, 2014

By a News Reporter-Staff News Editor at Life Science Weekly -- The United States of America, as represented by the Secretary of the Navy (Washington, DC) has been issued patent number 8796435, according to news reporting originating out of Alexandria, Virginia, by NewsRx editors (see also The United States of America, as represented by the Secretary of the Navy).

The patent's inventors are Delehanty, James B. (Washington, DC); Medintz, Igor L. (Washington, DC); Mattoussi, Hedi M. (Tallahassee, FL); Deschamps, Jeffrey R. (Laurel, MD); Dawson, Glyn (Chicago, IL); Dawson, Philip E. (San Diego, CA); Blanco-Canosa, Juan Bautista (A Coruna, ES); Boeneman, Kelly (Arlington, VA).

This patent was filed on February 22, 2013 and was published online on August 5, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "Quantum dots (QDs) provide many advantageous features that include high quantum yield, broad absorption spectra, large achievable Stokes shifts, narrow symmetric, size tunable emission spectra, and exceptional resistance to photo- and chemical degradation, making them attractive reagents for the long-term visualization of cellular structures and processes. See references 1-4.

"The methods employed to date for the intracellular delivery of QDs or other nanoparticles (NPs) can be grouped into three generalized categories based on their physicochemical nature. Passive delivery is a nonspecific process that relies on the inherent physicochemical properties of the QD (surface charge and/or functionalization) to mediate uptake.

"Facilitated delivery utilizes a delivery agent (e.g., a cationic peptide or a polymer) that is covalently attached to or electrostatically complexed with the QDs to specifically induce internalization. Both these techniques, while noninvasive, typically utilize the endocytic pathway which results in encapsulation of the QDs within intracellular endolysosomal vesicles and thus requires further strategies to liberate the sequestered QDs to the cytosol if that is ultimately desired. Examples methods of facilitated delivery include using additional chemicals such as sucrose or chloroquine or adding polymers such as polyethyleneimine during delivery to disrupt the endosomes by osmotic shock: such methods are generally quite toxic. Lastly, active delivery methods such as electroporation and microinjection deliver QDs directly to the cytosol through physical manipulation of the cell. However, these are highly invasive techniques that can often compromise the integrity of cellular structures and substantially reduce cellular viability (see reference 10). Thus, each of the previously described methods for delivery of nanoparticles (including quantum dots) is deficient in some way.

"Described herein are improvements in intracellular delivery of nanoparticles."

Supplementing the background information on this patent, NewsRx reporters also obtained the inventors' summary information for this patent: "In one embodiment, a nucleic acid encodes a polypeptide for delivery of a nanoparticle to the cytosol, the peptide comprising: (a) a nanoparticle association domain, (b) a spacer domain, © an uptake domain, and (d) a vesicle escape domain, wherein the domains (a) through (d) appear in the same order as listed above, and wherein the peptide, upon addition of a non-hydrolyzable lipophilic moiety to the vesicle escape domain and binding to a nanoparticle, is effective to induce uptake of a nanoparticle by a cell and delivery of the nanoparticle to the cytosol of the cell.

"In a further embodiment, the spacer comprises from between 6 and 15 proline residues, for example 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 proline residues.

"In another embodiment, a nanoparticle is delivered to the cytosol of a cell by providing to a cell with a nanoparticle attached to such a peptide.

"Exemplary nanoparticles include quantum dots."

For the URL and additional information on this patent, see: Delehanty, James B.; Medintz, Igor L.; Mattoussi, Hedi M.; Deschamps, Jeffrey R.; Dawson, Glyn; Dawson, Philip E.; Blanco-Canosa, Juan Bautista; Boeneman, Kelly. Modular Functional Peptides for the Intracellular Delivery of Nanoparticles. U.S. Patent Number 8796435, filed February 22, 2013, and published online on August 5, 2014. Patent URL:

Keywords for this news article include: Nanoparticle, Quantum Dots, Nanotechnology, Quantum Physics, Emerging Technologies, The United States of America as represented by the Secretary of the Navy.

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Source: Life Science Weekly

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