A Fibrosis-Targeting T <sub>1</sub> MRI Contrast Agent Synthesized via Photooxidative Self-Desulfurization of Porphyrin Thiourea
Bibliographic record
Abstract
Fibrosis is a silent disease that becomes untreatable and incurable in late stages, ultimately leading to organ failure. Early intervention can slow or even reverse progression, but current noninvasive tools like magnetic resonance imaging (MRI) and ultrasound are nonspecific and detect only advanced scar tissue. We present a fibrosis-targeting, nongadolinium MRI contrast agent for sensitive and specific in vivo imaging of fibrosis. Unlike conventional methods that infer scar content via stiffness or empty dead tissue space, our agent directly binds the excess collagen substrate of the scar tissue. To synthesize the agent, we conjugated an “MRI active” manganese porphyrin to a fibrosis-targeting free-base porphyrin via the first demonstration of porphyrin photooxidative self-desulfurization of aryl thiourea linkages to stable urea or guanidine linkages. The compound exhibited high affinity for acid-soluble collagen in a new scar and significantly reduced T 1 relaxation time in collagen gels. In a mouse model of diffuse myocardial fibrosis, the fibrosis-targeting agent highlighted scar tissue that was undetected by conventional late-gadolinium MRI.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".