Ultrashort peptides as exogenous second harmonic probes for bioimaging applications

Patent metadata

Field	Value
Publication number	US-10105454-B2
Application number	US-201515324144-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 8, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Various aspects of the present invention relate to a peptide based biomaterial for visualization by SHG microscopy. In particular the invention relates to the use of short peptides as a non-linear optical (NLO) material for second harmonic generation (SHG) microscopy. A preferred short peptide comprises LIVAGK (LK6) and contains a non-polar aliphatic tail (with decreasing hydrophobicity) and a polar head; and can self-assemble into hydrogels; wherein which the peptide forms a tunable fibrous structure for in vitro and in vivo imaging applications and is suitable in disease diagnostics such as amyloidosis, including 1) neuro-degenerative amyloidosis, e.g. Alzheimer's (AD), Parkinson's, Huntington's (PD), 2) non-neuropathic localized amyloidosis such as in Type II Diabetes, and 3) systemic amyloidosis that occurs in multiple tissues, e.g. cataracts and lattice corneal dystrophy (LCD), as well as drug delivery and/or wound dressings.

First claim

The invention claimed is:

1. A second harmonic generation (SHG) microscopy method for imaging a sample, the method comprising:
(a) contacting with a sample or a tissue a non-linear optical material that comprises peptides and/or peptidomimetics having the general Formula I:
Z a -(X) b -(Y) c -Z′ d    (I)

wherein
Z is an N-terminal protecting group;
a is 0 or 1;
X is, at each occurrence, independently selected from the group consisting of aliphatic amino acids and aliphatic amino acid derivatives, and wherein the overall hydrophobicity decreases from N- to C-terminus;
b is an integer selected from 1 to 7;
Y is selected from the group consisting of polar amino acids and polar amino acid derivatives;
c is 1 or 2;
Z′ is a C-terminal protecting group; and
d is 0 or 1,
and b+c is at least 2; and

(b) imaging the sample or tissue under a second harmonic generation (SHG) excitation wavelength to produce a SHG signature of the sample or tissue.

2. The method according to claim 1 , wherein the non-linear optical material comprises a hydrogel, a fibrous structure, or a peptide particle wherein the hydrogel, or the fibrous structure is formed by dissolving the peptide or peptidomimetic in an aqueous solution or wherein the peptide particle is formed by evaporating the aqueous solution from the hydrogel, or the fibrous structure.

3. The method of claim 2 , wherein the at least one peptide or peptidomimetic is dissolved in an aqueous solution at a concentration of 0.01 μg/ml to 100 mg/ml.

4. The method of claim 2 , further comprising exposing the peptide or peptidomimetic in aqueous solution to a temperature of 20° C. to 90° C.

5. The method of claim 2 , wherein the aqueous buffer comprises phosphate buffered saline (PBS).

6. The method of claim 2 , wherein the hydrogel, the fibrous structure or the peptide particle are used:
(a) as probes for monitoring cells, in vitro and/or in vivo (bio-)imaging, as exogenous SHG probes or as drug or gene delivery vehicles;
(b) for visualizing peptide-based tissue engineering scaffolds, comprising studying biological processes; or
(c) as a diagnostic, for the diagnosis of diseases comprising or associated with the aggregation of peptide or protein structures of amyloidosis.

7. The method of claim 1 , wherein the aliphatic amino acids and aliphatic amino acid derivatives and the polar amino acids and polar amino acid derivatives are either D-amino acids or L-amino acids.

8. The method of claim 1 , wherein the aliphatic amino acids are selected from the group consisting of alanine (Ala, A), homoallylglycine, homopropargylglycine, isoleucine (Ile, I), norleucine, leucine (Leu, L), valine (Val, V) and glycine (Gly, G).

9. The method of claim 1 , wherein all or a portion of the aliphatic amino acids are arranged in an order of decreasing amino acid size in the direction from N- to C-terminus, wherein the size of the aliphatic amino acids is defined as I=L>V>A>G.

10. The method of claim 1 , wherein the aliphatic amino acids have a sequence selected from the group consisting of

(SEQ ID NO: 1)

LIVAG,

(SEQ ID NO: 2)

ILVAG,

(SEQ ID NO: 3)

ILVAA,

(SEQ ID NO: 4)

LIVAA,

(SEQ ID NO: 5)

LAVAG,

(SEQ ID NO: 6)

IAVAG,

(SEQ ID NO: 7)

AIVAG,

(SEQ ID NO: 8)

GIVAG,

(SEQ ID NO: 9)

VIVAG,

(SEQ ID NO: 10)

ALVAG,

(SEQ ID NO: 11)

GLVAG,

(SEQ ID NO: 12)

VLVAG,

(SEQ ID NO: 13)

IVAG,

(SEQ ID NO: 14)

LIVA,

(SEQ ID NO: 15)

LIVG,

(SEQ ID NO: 16)

ILVA,

(SEQ ID NO: 17)

ILVG,

(SEQ ID NO: 18)

LVAG,

IVA

IVG,

VIG,

IVA,

VIA,

IV 

VI

(SEQ ID NO: 19)

Assignees

• Agency Science Tech & Res

Inventors

• Hauser Charlotte
• Ni Ming

Classifications

• A61K49/00 Primary

  Preparations for testing in vivo · CPC title

• A61K47/42

  Proteins; Polypeptides; Degradation products thereof; Derivatives thereof, e.g. albumin, gelatin or zein (oligopeptides having up to five amino acids {A61K47/183}; polyamino acids A61K47/34) · CPC title

• A61L27/227

  Other specific proteins or polypeptides not covered by A61L27/222, A61L27/225 or A61L27/24 · CPC title

• A61L26/008

  Hydrogels or hydrocolloids · CPC title

• A61L27/52

  Hydrogels or hydrocolloids · CPC title