Smart Peptide Hydrogel Activates in Tumors to Deliver Triple Cancer Therapy

The MMP-2 responsive hydrogel achieved 3.5-fold and 5.2-fold increases in CD8+ T cell infiltration in primary and distant tumors respectively, effectively suppressing primary, distant, and recurrent tumor growth through combined photothermal-chemo-immunotherapy.

Designed peptide hydrogel (aP/IR@FMKB) with MMP-2-cleavable and tumor-penetrating peptides. Loaded with bufalin nanoparticles, IR820, and anti-PD-L1. Tested in 4T1 cells (cytotoxicity, ICD induction), 3D spheroids (penetration), and primary/recurrent/distant tumor mouse models.

Cancer often requires multiple treatment modalities, but combining them causes severe side effects. A peptide-based platform that activates only at the tumor site delivers triple therapy locally while minimizing systemic toxicity — a major advance in precision oncology.

The future of cancer therapy lies in smart delivery systems that combine multiple treatment approaches with tumor-specific activation. This peptide hydrogel exemplifies the trend — using enzyme-responsive peptides as molecular switches that turn on therapy precisely where it is needed while leaving healthy tissue unharmed.

Preclinical mouse study with 4T1 breast cancer model — may not translate to all cancer types. Complex manufacturing could hinder clinical development. Photothermal component requires external near-infrared light, limiting treatment to accessible tumors. Long-term safety and immunological consequences unknown.