Targeted Photodynamic Diagnosis and Therapy for Esophageal Cancer: Potential Role of Functionalized Nanomedicine

Abstract

Esophageal cancer is often diagnosed at the late stage when cancer has already spread and is characterized by a poor prognosis. Therefore, early diagnosis is vital for a better and efficient treatment outcome. Upper endoscopy with biopsy is the standard diagnostic tool for esophageal cancer but is challenging to diagnose at its premalignant stage, while conventional treatments such as surgery, chemotherapy, and irradiation therapy, are challenging to eliminate the tumor. Photodynamic diagnosis (PDD) and therapy (PDT) modalities that employ photosensitizers (PSs) are emerging diagnostic and therapeutic strategies for esophageal cancer. However, some flaws associated with the classic PSs have limited their clinical applications. Functionalized nanomedicine has emerged as a potential drug delivery system to enhance PS drug biodistribution and cellular internalization. The conjugation of PSs with functionalized nanomedicine enables increased localization within esophageal cancer cells due to improved solubility and stability in blood circulation. This review highlights PS drugs used for PDD and PDT for esophageal cancer. In addition, it focuses on the various functionalized nanomedicine explored for esophageal cancer and their role in targeted PDD and PDT for diagnosis and treatment.

Systematic review and meta-analysis of endoscopic ultrasonography in staging diagnosis of esophageal cancer after neoadjuvant radiotherapy and chemotherapy

“…Esophageal cancer, as a common malignant tumor of digestive tract, has a high morbidity and mortality rate (1,2). Because of its insidious onset and high malignancy, patients are often in the advanced stage at the time of seeing a doctor, and sometimes other parts are found to be invaded during surgery, so radical resection cannot be performed (3)(4)(5).…”

Phosphorescent Metal Halide Nanoclusters for Tunable Photodynamic Therapy

“…The phosphorescence and singlet oxygen formation are two reversible processes, which shows a strong oxygen dependence as shown in Figure S1. Blue light is commonly used in FDA‐approved PDT for skin cancer and pre‐cancerous lesions [58,59] as well as colorectal [60] and esophageal cancers [61,62] . The broad emission spectrum of Mo‐based NCs in the NIR region (650 ‐ 1200 nm) is in a spectroscopic window with minimal absorbance by biomolecules, reducing background noise [63] .…”

Advancements in photodynamic therapy of esophageal cancer

“…Nanotherapeutics as delivery tools for drugs have the potential to improve PDT therapeutic impact and are currently being developed and tested mostly in pre-clinical trials ( 114 ). The potential role of PDT in functionalized nanomedicine is often highlighted ( 115 , 116 ). Fluoroscopy-guided PDT by using nanoparticle albumin-bound paclitaxel for esophageal cancer after chemoradiotherapy is known and well-described ( 117 ).…”