In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide

Peptide-based fluorescent probes for the diagnosis of tumor and image-guided surgery

Fluorescent contrast agents are instrumental in amplifying signals, thereby enhancing the sensitivity and accuracy of live optical imaging. However, a significant proportion of traditional fluorescent contrast agents exhibit drawbacks such as short half-life, suboptimal biocompatibility, and inadequate tumor targeting, all of which impede effective imaging guidance. Peptides, derived from natural structures, offer a flexible modular design that can be precisely engineered and adjusted using synthetic methods to achieve specific biological activity and pharmacokinetic properties. They bind with designated receptors to exert their effects, demonstrating high specificity. The development of fluorescent probes based on peptides significantly overcomes the limitations of conventional contrast agents, offering superior performance. This article provides a comprehensive review of three strategies for constructing peptide-based fluorescent probes, delving into their distinct design concepts, mechanisms of action, and innovative aspects. It also highlights the potential applications of peptide-based fluorescent probes in tumor diagnosis and image-guided surgery, offering insights into their future clinical transformation.

Innovative Diagnostic Peptide-Based Technologies for Cancer Diagnosis: Focus on EGFR-Targeting Peptides

Active targeting using biological ligands has emerged as a novel strategy for the targeted delivery of diagnostic agents to tumor cells. Conjugating functional targeting moieties with diagnostic probes can increase their accumulation in tumor cells and tissues, enhancing signal detection and, thus, the sensitivity of diagnosis. Due to their small size, ease of chemical synthesis and site-specific modification, high tissue penetration, low immunogenicity, rapid blood clearance, low cost, and biosafety, peptides offer several advantages over antibodies and proteins in diagnostic applications. Epidermal growth factor receptor (EGFR) is one of the most promising cancer biomarkers for actively targeting diagnostic and therapeutic agents to tumor cells due to its active involvement and overexpression in various cancers. Several peptides for EGFR-targeting have been identified in the last decades, which have been obtained by multiple means including derivation from natural proteins, phage display screening, positional scanning synthetic combinatorial library, and in silico screening. Many studies have used these peptides as a targeting moiety for diagnosing different cancers in vitro, in vivo, and in clinical trials. This review summarizes the progress of EGFR-targeting peptide-based assays in the molecular diagnosis of cancer.

A narrative review of near-infrared fluorescence imaging in hepatectomy for hepatocellular carcinoma

Hepatectomy is a main therapeutic strategy for hepatocellular carcinoma (HCC), which requires removal of primary and disseminated tumors and maximum preservation of normal liver tissue. However, in a clinical operation, it is difficult to recognize the tumor tissue and its boundary with the naked eye and palpation, which often leads to insufficient or excessive resection. Near-infrared fluorescence (NIRF) imaging, a non-invasive, real-time, low-cost, and highly sensitive imaging technique has been extensively studied in surgical navigation. With the development of fluorescence imaging system and fluorescent probe, intraoperative tumor detection and margin definition can be achieved, making the operation more accurate. Advances in fluorescence imaging of HCC in the NIR region have focused on the traditional first NIR window (NIR-I, 700–900 nm), and have recently been extended to the second NIR window (NIR-II, 1,000–1,700 nm). Compared with NIR-I imaging, fluorescence imaging in the NIR-II exhibits great advantages, including higher spatial resolution, deeper penetration depth, and lower optical absorption and scattering from biological substrates with minimal tissue autofluorescence. There is no doubt that developing novel NIRF probes for in vivo imaging of HCC has high significance and direct impact on the field of liver surgery. In this article, the development of various NIRF probes for fluorescence image guided HCC hepatectomy is reviewed, and current challenges and potential opportunities of these imaging probes are discussed.

Fluorescence Image-Guided Surgery - a Perspective on Contrast Agent Development

In the past several decades, a number of novel fluorescence image-guided surgery (FGS) contrast agents have been under development, with many in clinical translation and undergoing clinical trials. In this review, we have identified and summarized the contrast agents currently undergoing clinical translation. In total, 39 novel FGS contrast agents are being studied in 85 clinical trials. Four FGS contrast agents are currently being studied in phase III clinical trials and are poised to reach FDA approval within the next two to three years. Among all novel FGS contrast agents, a wide variety of probe types, targeting mechanisms, and fluorescence properties exists. Clinically available FGS imaging systems have been developed for FDA approved FGS contrast agents, and thus further clinical development is required to yield FGS imaging systems tuned for the variety of contrast agents in the clinical pipeline. Additionally, study of current FGS contrast agents for additional disease types and development of anatomy specific contrast agents is required to provide surgeons FGS tools for all surgical specialties and associated comorbidities. The work reviewed here represents a significant effort from many groups and further development of this promising technology will have an enormous impact on surgical outcomes across all specialties.