HSA-ZW800-PEG for Enhanced Optophysical Stability and Tumor Targeting.

Small molecule fluorophores often face challenges such as short blood half-life, limited physicochemical and optical stability, and poor pharmacokinetics. To overcome these limitations, we conjugated the zwitterionic near-infrared fluorophore ZW800-PEG to human serum albumin (HSA), creating HSA-ZW800-PEG. This conjugation notably improves chemical, physical, and optical stability under physiological conditions, addressing issues commonly encountered with small molecules in biological applications.

Ultralow Background Near-Infrared Fluorophores with Dual-Channel Intraoperative Imaging Capability.

Two of the most pressing challenges facing bioimaging are nonspecific uptake of intravenously administered contrast agents and incomplete elimination of unbound targeted agents from the body. Designing a targeted contrast agent that shows fast clearance from background tissues and eventually the body after complete targeting is key to the success of image-guided interventions. Here, this work describes the development of renally clearable near-infrared contrast agents and their potential use for dual-channel image-guided tumor targeting.

P800SO3-PEG: a renal clearable bone-targeted fluorophore for theranostic imaging.

Background: Due to the deep tissue penetration and reduced scattering, NIR-II fluorescence imaging is advantageous over conventional visible and NIR-I fluorescence imaging for the detection of bone growth, metabolism, metastasis, and other bone-related diseases.

Methods: Bone-targeted heptamethine cyanine fluorophores were synthesized by substituting the meso-carbon with a sulfur atom, resulting in a bathochromic shift and increased fluorescence intensity. The physicochemical, optical, and thermal stability of newly synthesized bone-targeted NIR fluorophores was performed in aqueous solvents.