Polypeptide Magnetic Nanoparticles for CTC Isolation and Molecular Typing

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Solution Overview

Problem

Current tumor detection methods, such as imaging and tissue biopsy, are limited in resolution and invasiveness, and traditional pathological classification fails to predict tumor behavior accurately, necessitating molecular typing for personalized treatment, especially for circulating tumor cells (CTCs) which carry tumor genetic and protein information.

Innovation Solution

Development of magnetic nanoparticles functionalized with specific polypeptides that target CTCs, allowing for their isolation and molecular typing of markers like HER2, ER, PR, AR, PD-L1, EGFR, CXCR4, and VEGFR, using a method involving peptide-functionalized iron oxide magnetic nanoparticles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If imaging methods are used for tumor detection, then the detection process is non-invasive, but the resolution is insufficient and tumors less than 5mm cannot be detected

Engineering Contradiction:
Improvedetection resolutionVSAvoiddetection capability for small tumors
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the detection process into two stages: first using imaging to locate tumor regions, then using magnetic nanoparticle-based liquid biopsy to detect circulating tumor cells with high sensitivity. This segmentation allows combining the non-invasive advantage of imaging with the high precision of molecular detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces magnetic nanoparticles functionalized with targeting peptides as intermediaries that specifically bind to circulating tumor cells. These nanoparticles serve as mediators between the blood sample and detection system, enabling highly sensitive detection of CTCs carrying tumor genetic and protein information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If tissue biopsy is performed to obtain tumor samples, then sufficient tissue for multiple analyses can be obtained, but the procedure causes pain and risks to patients

Engineering Contradiction:
Improveamount of tumor sampleVSAvoidpatient pain and risks
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent extracts circulating tumor cells from peripheral blood instead of obtaining tissue samples through invasive biopsy. By isolating CTCs that naturally shed from the primary tumor into the bloodstream, the method obtains sufficient tumor genetic and protein information without causing patient pain or procedural risks.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent utilizes the body's natural process where tumor cells spontaneously detach and enter circulation. The detection system passively captures these self-released CTCs through magnetic nanoparticle binding, eliminating the need for active tissue extraction and reducing patient burden.

Inventive Principle:
Principle #25Self-service

3Productivity

If traditional pathological classification is used for tumor diagnosis, then the classification process is simple and quick, but the ability to predict tumor behavior and guide personalized treatment is limited

Engineering Contradiction:
Improvediagnosis speedVSAvoidtumor prediction accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent creates a multi-functional detection system using magnetic nanoparticles that can simultaneously detect multiple tumor markers and molecular characteristics of CTCs. This universal platform provides comprehensive molecular typing information including genetic mutations and protein expressions, enabling both rapid diagnosis and precise treatment guidance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent employs composite magnetic nanoparticles with dual functionality: magnetic cores for separation and peptide functionalization for specific tumor cell recognition. This composite structure enables simultaneous isolation and molecular characterization of CTCs, providing comprehensive data for personalized treatment decisions.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enables high sensitivity and specificity in detecting and typing CTCs, facilitating personalized medicine by providing real-time condition tracking and treatment guidance, avoiding invasive procedures and improving treatment efficacy.

Implementation Method 1

a magnetic nanoparticle bearing a polypeptide comprises: a specific targeting polypeptide and magnetic nanoparticle

Methodology Applied
Scientific EffectMagnetic properties: Magnetism

Implementation Method 2

peptide-based isolation of circulating tumor cells by magnetic nanoparticles

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3974830B1Polypeptide magnetic nanoparticle, preparation method therefor and use thereof
Publication Date: 2025.09.10 BEIJING NANOPEP BIOTECH CORP LTD
  • EP3974830B1 patent drawingFigure 1(A)~2(B)
  • EP3974830B1 patent drawingFigure 3~4
  • EP3974830B1 patent drawingFigure 5~6

AI summary

A polypeptide magnetic nanoparticle, comprising: a specific targeting polypeptide and a magnetic nanoparticle. The amino acid sequence of the specific targeting polypeptide is VRRDAPRFSMQGLDA-X, and the C-terminal X thereof is a sequence of 5 to 20 amino acids. The amino acid in the amino acid sequence of C-terminal X is selected from one or more of: C, G, and N. The polypeptide magnetic nanoparticle can be used for CTC detection and molecular typing of various cancer types, including esophageal cancer, liver cancer, lung cancer, stomach cancer, bladder cancer, skin cancer, melanoma, breast cancer, colorectal cancer, cervical cancer, etc. Biomarkers of CTC molecular typing include PD-L1, HER2, ER, PR, AR, EGFR, VEGFR, CXCR4, etc. The polypeptide magnetic nanoparticle is helpful for CTC detection and the qualitative and semiquantitative analysis of expression levels of biomarkers at CTC level, thereby performing precise therapy such as targeted individualized targeted therapy or immunotherapy on patients.