HER2-Targeting RK Polypeptide Dimer for Noninvasive Tumor Imaging
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Solution Overview
Problem
Current methods for diagnosing HER2-positive breast cancer, such as biopsies, are invasive and have inconsistencies in assessing HER2 expression levels, and existing molecular probes lack specificity and stability for real-time monitoring of trastuzumab treatment efficacy.
Innovation Solution
A novel rk polypeptide radiopharmaceutical comprising a dimerized rk polypeptide with a D-amino acid sequence and a radionuclide labeled by a bifunctional chelating agent, optimized with a PKM linker for improved targeting and pharmacokinetics, allowing for precise HER2 diagnosis and treatment monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If biopsy is used to determine HER2 expression level, then HER2 expression can be assessed, but the method is invasive and has high inconsistency rate between primary and metastatic lesions
Solution Approach 1:
The patent replaces the mechanical/invasive biopsy system with a molecular imaging system using radiopharmaceuticals. The rk polypeptide radiopharmaceutical targets HER2 receptors in vivo, allowing non-invasive visualization and quantification of HER2 expression levels in both primary and metastatic lesions through nuclear medicine imaging, thereby eliminating the need for repeated invasive biopsies while improving measurement consistency
Solution Approach 2:
The patent introduces an intermediary molecular probe (rk polypeptide radiopharmaceutical) that specifically binds to HER2 receptors. This intermediary enables indirect assessment of HER2 expression levels through imaging, avoiding direct tissue sampling while providing consistent measurements across different lesion sites
2Reliability
If conventional molecular probes are used for HER2 targeting, then tumor detection is possible, but they lack specificity and stability for real-time monitoring of trastuzumab treatment efficacy
Solution Approach 1:
The patent modifies the molecular probe structure by using D-amino acid sequence (rnwelrlk) instead of conventional L-amino acids, which confers resistance to proteolytic degradation and dramatically improves in vivo stability. The dimeric structure with optimized linker length enhances binding affinity and specificity for HER2 receptors, enabling reliable real-time monitoring of trastuzumab treatment efficacy
Solution Approach 2:
The patent creates a composite radiopharmaceutical structure combining the rk polypeptide targeting moiety with a radionuclide (99mTc) through a bifunctional chelating agent (HYNIC). This composite structure integrates the specificity of the polypeptide-HER2 interaction with the detectability of the radionuclide, achieving both high targeting specificity and treatment monitoring stability
3Reliability
If radionuclide is labeled to rk polypeptide monomer, then HER2 targeting is achieved, but metabolic stability in vivo is insufficient
Solution Approach 1:
The patent merges two rk polypeptide monomers into a dimeric structure, which significantly enhances metabolic stability in vivo. The dimeric configuration provides increased resistance to proteolytic degradation and improves pharmacokinetic properties while maintaining HER2 targeting capability, making the radiopharmaceutical suitable for clinical imaging applications
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 rk polypeptide radiopharmaceutical enhances metabolic stability, tumor uptake, and specificity, enabling accurate HER2-positive tumor diagnosis and real-time monitoring of trastuzumab efficacy with high sensitivity and specificity.
Implementation Method 1
a radionuclide (99mTc, 68Ga, 64Cu, 111In, 90Y or 177Lu), and in particular, to radionuclide 99mTc
Implementation Method 2
wherein the radionuclide labels the rk polypeptide dimer through a chelating agent
Data Source
AI summary
Disclosed are an rk polypeptide radiopharmaceutical targeting HER2, and a preparation method therefor. The rk polypeptide radiopharmaceutical comprises an rk polypeptide dimer and a radionuclide, wherein the radionuclide marks the rk polypeptide dimer by means of a chelating agent, the rk polypeptide dimer is a polypeptide dimer formed by connecting PKM and rk polypeptide monomers and then dimerizing two rk polypeptide monomers connected to the PKM; each rk polypeptide monomer is a D-type amino acid linear eight-membered polypeptide, and the sequence of the rk polypeptide monomer is as follows: Arg-Asn-Trp-Glu-Leu-Arg-Leu-Lys; and the PKM represents a pharmacokinetic modifying molecule. The radiopharmaceutical is used for imaging diagnosis of HER2-positive tumor patients, and medication guidance and real-time therapeutic effect monitoring of patients treated by monoclonal antibodies of the anti-cancer drug trastuzumab.