Self-Assembled Nanobody-Albumin Platform with Dye Encapsulation for NIR-II Imaging-Guided Photodynamic Therapy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Oncology

Background:

• Nanobodies offer advantages over immunoglobulin G (IgG) but face challenges like low drug capacity and rapid clearance.
• Efficient delivery systems are crucial for nanobody-based therapeutics and diagnostics.

Purpose of the Study:

• To develop a tumor-targeted nanobody platform using albumin binding and dye encapsulation.
• To enhance nanobody pharmacokinetics, tumor accumulation, and theranostic capabilities.

Main Methods:

• Genetically engineered nanobodies for human serum albumin (HSA) binding to create a self-assembling carrier.
• Encapsulated cyanine dyes within albumin for enhanced near-infrared-II (NIR-II) fluorescence and singlet oxygen generation.
• Evaluated the platform in colorectal cancer xenograft models for imaging and photodynamic therapy.

Main Results:

• The nanobody-albumin platform demonstrated improved pharmacokinetics and significantly enhanced tumor accumulation.
• Achieved high-contrast NIR-II imaging and effective photodynamic therapy with a low light dose.
• The self-assembled system showed superior nanobody retention in tumors compared to clearance organs.

Conclusions:

• The engineered nanobody-albumin platform provides a viable strategy for precision theranostic agents.
• Albumin binding effectively overcomes nanobody limitations, improving delivery efficiency and therapeutic outcomes.
• This approach offers a bioderived and efficient method for cancer theranostics.