Heart-Targeting Peptide Shows No Toxicity in Comprehensive Safety Testing

CTP (sequence: APHLSSQYSRT) showed no decrease in human cardiomyocyte viability in vitro. Of 78 protein channels tested, only OPRM1 and COX2 showed any interaction, and neither was expressed in mouse heart tissue. In 60 mice followed for up to 14 days, CTP caused no changes in blood pressure, blood counts, liver function, kidney function, thyroid function, or cardiac size/function on MRI. The peptide appears safe as a cardiac delivery vector.

Combined in vitro and in vivo toxicity assessment. Cell viability tested in human left ventricular myocyte cell line. Ion channel and GPCR profiling across 78 targets. In vivo: 60 CD1 mice (male/female) received CTP at 150 µg/kg, with cohorts euthanized at days 0, 1, 2, 7, and 14 for blood counts, metabolic profiling, and organ function tests. Blood pressure monitored acutely at 10 mg/kg dose. Cardiac MRI before and after injection.

Delivering drugs specifically to the heart while avoiding other organs is a major unmet need in cardiology. CTP already delivers imaging agents, drugs, nanoparticles, and even miRNA to heart cells within minutes. Demonstrating safety clears a critical hurdle toward human clinical trials.

Heart-targeting peptides could transform cardiology by enabling precise drug delivery to heart muscle cells. If CTP advances to human trials, it could make heart failure treatments more effective with fewer side effects by concentrating drugs where they're needed.

Only acute single-dose toxicity tested — chronic administration effects unknown. Mice were tested with CTP alone, not conjugated to any therapeutic cargo (which could change the safety profile). Only 14-day follow-up. No human pharmacokinetic or toxicity data. GLP (good laboratory practice) studies still needed before human trials.