Fluorescent compound comprising a fluorophore conjugated to a pH-triggered polypeptide
Inventors
Reshetnyak, Yana K. • Andreev, Oleg A. • Engelman, Donald M.
Assignees
Yale University • Rhode Island University
Publication Number
US-12290575-B2
Publication Date
2025-05-06
Expiration Date
2037-09-22
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Abstract
The present subject matter provides compounds, compositions, and methods for identifying, monitoring, treating, and removing diseased tissue. Compounds, compositions, and methods for identifying, monitoring, and detecting circulating fluids such as blood are also provided.
Core Innovation
The invention discloses fluorescent compounds and compositions comprising a pH-triggered polypeptide (pHLIP® peptide) covalently linked to a fluorophore, such as indocyanine green (ICG). These compounds demonstrate increased fluorescence when the conjugate is inserted into cell membranes, enabling the identification, monitoring, and removal of diseased tissue, including cancerous and precancerous lesions. The core technology exploits the property that pHLIP® peptides insert into membrane bilayers at low pH — a characteristic of diseased tissues like tumors.
The invention addresses the problem of inadequate specificity and rapid clearance of conventional fluorescent dyes such as free ICG, which limits their use in diagnostic imaging and intraoperative procedures. In particular, current methodologies for detecting bladder cancer and other malignancies rely on non-targeted dyes, which cannot selectively mark early-stage lesions or persist long enough for extended imaging sessions, thus requiring high or repeated doses with associated side effects and workflow disruptions.
By conjugating ICG or similar fluorophores to pH-responsive polypeptides, the compounds provided selectively target and illuminate acidic, diseased tissues, while exhibiting prolonged retention in circulation. This technology allows for improved tumor visualization, enhanced differentiation of diseased versus healthy tissue, and the ability to guide surgical removal of malignancies or conduct in vivo/ex vivo diagnostics with high sensitivity and specificity.
Claims Coverage
The independent claims focus on inventive features related to methods for removing diseased or damaged tissue using pH-triggered polypeptide fluorophore compounds, including their application in both in vivo and ex vivo settings.
Method for removing diseased or damaged tissue using a pH-triggered polypeptide fluorophore compound
A method comprising administering a pH-triggered polypeptide fluorophore compound having a specified structure to a subject, enabling removal of diseased or damaged tissue. The method includes: - Administering the compound. - Exposing the subject to electromagnetic radiation suitable for the compound's excitation. - Detecting the emitted electromagnetic radiation from the compound in tissue. - Utilizing the detected signal for removal or guidance of removal of diseased or damaged tissue. The method includes administration by instillation, injection, topical, mucosal, or oral routes, the option to wash the subject to remove excess compound, and detection both in vivo and ex vivo.
Method for ex vivo removal of diseased or damaged tissue using a pH-triggered polypeptide fluorophore compound
A method comprising contacting a biological sample from a subject, ex vivo, with a pH-triggered polypeptide fluorophore compound having a specified structure. The steps include: - Contacting the sample (which may be a tissue biopsy, surgically removed tissue, or blood) with the compound. - Washing the sample to remove excess compound before detection. - Detecting emitted radiation to distinguish diseased or damaged from normal tissue for subsequent removal. The method further covers use of a pharmaceutically acceptable carrier with the compound and application for surgical margin determination.
In summary, the inventive features center on methods using pH-triggered polypeptide fluorophore compounds for detecting and enabling removal of diseased or damaged tissue, with claims spanning both in vivo and ex vivo applications, including provisions for various modes of administration, detection techniques, and use in surgical guidance.
Stated Advantages
Allows more specific and efficient targeting of diseased, acidic tissues such as tumors and precancerous lesions, improving detection and aiding surgical removal.
Prolongs circulation time and imaging window of fluorophores like ICG compared to free dye, enabling imaging over 2–3 hours rather than 2–5 minutes.
Enhances fluorescence intensity (up to 25-fold) upon membrane insertion, resulting in higher tumor to background contrast.
Reduces the effective dose of fluorophore required for imaging, potentially lowering side effects and minimizing phototoxicity compared to administration of free ICG.
Improves early detection of cancer and precancerous lesions, including carcinoma in situ and dysplasia, providing higher sensitivity and specificity than standard methods.
Facilitates intraoperative, real-time surgical guidance, enabling more complete and precise tumor removal based on fluorescence.
Simplifies workflow by potentially requiring only a single administration for an entire procedure, reducing the need for repeated dye injections and minimizing disruption.
Enables rapid, ex vivo assessment of surgical specimens or biopsies without the delay and complexity of traditional pathological staining methods.
Has applicability to a broad range of diseases and tissue types, including both cancerous and non-cancerous but acidic or damaged tissues.
Documented Applications
In vivo detection, imaging, and removal of cancerous and precancerous tissue in organs such as the bladder, upper urinary tract, kidney, prostate, breast, head and neck, oral cavity, pancreas, lungs, liver, cervix, ovaries, brain, and lymph nodes.
Fluorescence angiography for visualization of blood vessels and assessment of blood flow and tissue perfusion in ophthalmologic procedures, cardiothoracic surgery, neurosurgery, hepatobiliary surgery, reconstructive surgery, cholecystectomy, colorectal resection, brain surgery, muscle perfusion, wound, trauma, and laparoscopic surgery.
Visualization, mapping, and detection of lymph nodes, including those with metastatic cancer cells.
Ex vivo imaging and staining of human specimens, including tissue biopsies, surgically removed tissues, surgically removed liquids, and blood, for diagnostic purposes.
Use in fluorescence-guided surgery to determine tumor margins and guide resection.
Assessment and imaging of tissue perfusion, hemodynamics, burns, trauma, and sites of infection during surgical or diagnostic procedures.
Localization of lesions for surgery or monitoring, and marking of lesions for subsequent identification.
Monitoring treatment response or disease progression after surgical or therapeutic interventions.
Topical administration to detect cancers and precancerous lesions in the bladder (by instillation), oral cavity (mouthwash or spray), skin (spray), cervix (spray), colon (spray), and airway passages (spray or inhalation for lung).
Research use as a diagnostic, imaging, or ex vivo imaging agent and as a research tool for tissue, vascular, or renal studies.
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