pH-Ultrasensitive Polyester Nanoprobe for High-Contrast Tumor Imaging with Superior Biocompatibility.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Medical Imaging

Background:

• Transistor-like nanoprobes show promise for tumor imaging via pH detection.
• Existing probes face cytotoxicity and biosafety risks due to interactions with cell membranes.

Purpose of the Study:

• To develop pH-ultrasensitive polyester nanoprobes (pUPNs) with minimal toxicity and tunable responsiveness.
• To enhance biocompatibility and tumor imaging contrast through novel nanostructure design.

Main Methods:

• Self-assembly of pH-responsive polyesters with sterically hindered backbones.
• Covalent grafting of ionizable tertiary amines and self-quenched fluorescent dyes onto side chains.
• Evaluation of nanoprobes' pH sensitivity, cytotoxicity, and in vivo biocompatibility.

Main Results:

• pUPNs demonstrated tunable pH responsiveness and minimal toxicity.
• Nanoprobes with lower transition pH showed superior tumor imaging contrast.
• pUPNs exhibited excellent biocompatibility, with no detectable hepatic or renal toxicity after intravenous administration.

Conclusions:

• A design platform for pH-ultrasensitive nanoprobes was established.
• Increased steric hindrance in polymer backbones enhances sensitivity and biocompatibility.
• pUPNs represent a promising tool for sensitive and safe tumor imaging.