Synthesis And In Vivo Imaging Application Of Functional Photoacoustic Dyes

Bio-imaging technology plays a critical role in modern medical diagnosis and treatment, it’s an important technology to study the structure and function of biological tissues and organs. For drug carrier developers, the tracking of the target molecules by biological imaging technology is an important way to study its pharmacokinetics. Development of various molecular imaging probes provides a great convenience for scientific research in the medical field.Photoacoustic imaging technology is the latest developed biological imaging technology which combines the advantages of optical imaging and acoustic imaging technology. It has a deep penetration in biological tissue while obtains high contrast, high-resolution images, indicating extensive application prospects in the field of biological nondestructive testing. Through the use of specific molecules as photoacoustic contrast agents, photoacoustic imaging can provide many important informations in novel drug delivery systems, targeted therapy, cancer detection or other fields. It’s a prerequisite for macromolecular drug carrier developers that the carrier should not only act on the tissue or organ lesions occur, but also can be completely degraded and excreted from the body. Therefor, the tracking its bio-distribution and metabolism in vivo are very important. Photoacoustic imaging technology in real-time, nondestructive detection of target molecules on the distribution and metabolism in vivo, provides researchers a more convenient and efficient means of research. However, the current molecular probes devoted to photoacoustic imaging are far from satisfactory. Near-infrared fluorescent dye can be used in photoacoustic imaging, but photoacoustic efficiency is relatively low, and their prices are usually very expensive.In this paper, near infrared absorbers widely used in computer-to-plate technology (CTP) were modified into a series of functional photoacoustic imaging dye. The photoacoustic imaging dyes prepared with amino, carboxyl and activated esters can be widely applied as markers of various biological materials. Experimental results indicated that these dyes exhibit low toxicity, efficient features in the application. These dyes can be easily bonded to various carriers with the functional groups. The study of subcutaneous injection of PEG modified photoacoustic dyes proved the feasibility of in vivo application of these dyes, and higher photoacoustic signal than near-infrared fluorescent dye (ICG). By labeling macromolecular carrier material poly (L-glutamic acid)-g-methoxy poly (ethylene glycol) with the prepared amino photoacoustic dye, we successfully tracked its bio-distribution in mice at different time points, and concluded their metabolic pathway. These studies demonstrated the feasibility of these functional photoacoustic imaging dyes in practical applications, provided convenience for drug carrier developers, promoted and expanded the scope of application of these photoacoustic imaging techniques, which has application prospects in the field of novel pharmaceutical preparations development and diagnosis and treatment of disease.The above results are expected to contribute to the promotion and application of photoacoustic imaging technology, and provide more economical, convenient and efficient research tools for researchers and developers of pharmaceutical carriers.