Cellular Synthesis of Targeted Ultrasound Molecular Imaging Probe and Its Application in Prostate Cancer Diagnosis

The traditional construction of targeted ultrasound molecular imaging probes relies on multistep chemical synthesis strategies, which are time-consuming and inefficient, thereby limiting technological advancements. To address this, we developed a novel genetic engineering approach for biosynthesizing targeted nanoprobes for prostate cancer diagnosis.

The anti-PSMA nanobody-encoding gene was fused to the C-terminus of the gas vesicle structural protein gene GvpC and cloned into a pBV220 plasmid with a hyperthermia-responsive gene expression circuit. This recombinant plasmid was transformed into E. coli BL21(A1) harboring pET-28a-ΔGvpC-eGVs plasmids to create PSMA-GVs@E. coli genetically engineered bacteria. The probe assembly were involved in two-step gene expression procedure. ΔGvpC-eGVs were first induced by IPTG, followed by temperature-triggered (42°C) production of PSMA-GvpC proteins that spontaneously assembled onto GVs.

The biosynthesized PSMA-eGVs probes exhibited a uniform size (100-200 nm) and demonstrated excellent targeting capability in prostate cancer cells. In vivo studies confirmed effective tumor vascular penetration and specific binding with PSMA-positive tumor cells, resulting in significantly stronger acoustic signals than the non-targeted EGFP-eGVs controls.

This cellular synthesis strategy enables efficient production of targeted ultrasound molecular imaging probes through genetically engineering technology, providing a promising platform for precision cancer diagnostics.