Biodegradable Biliverdin Nanoparticles for Efficient Photoacoustic Imaging

Abstract

Photoacoustic imaging has emerged as a promising imaging platform with a high tissue penetration depth. However, biodegradable nanoparticles, especially those for photoacoustic imaging, are rare and limited to a few polymeric agents. The development of such nanoparticles holds great promise for clinically translatable diagnostic imaging with high biocompatibility. Metabolically digestible and inherently photoacoustic imaging probes can be developed from nanoprecipitation of biliverdin, a naturally occurring heme-based pigment. The synthesis of nanoparticles composed of a biliverdin network, cross-linked with a bifunctional amine linker, is achieved where spectral tuning relies on the choice of reaction media. Nanoparticles synthesized in water or water containing sodium chloride exhibit higher absorbance and lower fluorescence compared to nanoparticles synthesized in 2-(N-morpholino) ethanesulfonic acid buffer. All nanoparticles display high absorbance at 365 and 680 nm. Excitation at near-infrared wavelengths leads to a strong photoacoustic signal, while excitation with ultraviolet wavelengths results in fluorescence emission. In vivo photoacoustic imaging experiments in mice demonstrated that the *

Systemic Review of Biodegradable Nanomaterials in Nanomedicine

“…Photoacoustic imaging has also emerged as a promising imaging platform with a high tissue penetration depth [69,70]. It applies both NIR laser and ultrasound for the imaging purpose.…”

“…Recently, not only polymers, but also natural materials are being engineered as biodegradable imaging agents. Fathi et al have recently developed a photoacoustic imaging nanoprobe from nanoprecipitation of biliverdin, a naturally occurring heme-based pigment, which can be completely biodegraded to biliverdin reductase, a ubiquitous enzyme found in the body [69]. Excitation at near-infrared wavelengths leads to a strong photoacoustic signal, while excitation with ultraviolet wavelengths results in fluorescence emission [69].…”

“…Fathi et al have recently developed a photoacoustic imaging nanoprobe from nanoprecipitation of biliverdin, a naturally occurring heme-based pigment, which can be completely biodegraded to biliverdin reductase, a ubiquitous enzyme found in the body [69]. Excitation at near-infrared wavelengths leads to a strong photoacoustic signal, while excitation with ultraviolet wavelengths results in fluorescence emission [69]. In vivo experiments demonstrated that these nanoparticles accumulate in lymph nodes, suggesting that they can be used as a means to detect metastasized cancer [69].…”

“…Excitation at near-infrared wavelengths leads to a strong photoacoustic signal, while excitation with ultraviolet wavelengths results in fluorescence emission [69]. In vivo experiments demonstrated that these nanoparticles accumulate in lymph nodes, suggesting that they can be used as a means to detect metastasized cancer [69]. Similarly, MTP1, a tumor metastasis targeting peptide, has been employed to modify the indocyanine green (ICG)-loaded PEG-PLGA micelles for targeted imaging of cervical cancer and metastasis [72].…”

Materdicine: Interdiscipline of materials and medicine

“…To compete efficiently against small‐molecule CAs, nanomaterials must cause negligible biosafety risk after in vivo administration, while furnishing at least one substantial superiority, such as improved resolution, augmented imaging sensitivity, or multiplexing capability 30 . Currently, the representative nanomaterial‐based imaging modalities in clinical settings or preclinical research include MRI, 31 positron emission tomography (PET), 32 single‐photon emission computed tomography, 33 computed tomography (CT), 34 optical fluorescence imaging, 35 PA imaging, 36 and ultrasound (US) imaging 37 …”