Study on the diagnosis of rabbit VX2 esophageal cancer and stent-therapy efficacy based on multiphoton microscopy

Label-free characterization of collagen fibers in cancerous esophagus tissues using ratiometric nonlinear optical microscopy

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The issue of classifying esophageal cancer at various developmental stages is crucial for determining the optimized treatment protocol for the patients, as well as the prognosis. Precision improvement in staging esophageal cancer keeps seeking quantitative and analytical imaging methods that could augment histopathological techniques. In this work, we used nonlinear optical microscopy for ratiometric analysis on the intrinsic signal of two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) from single collagen fibers only in submucosa of esophageal squamous cell carcinoma (ESCC). The blind tests of TPEF/SHG and forward (F)/backward (B) SHG were demonstrated to compare with the histology conclusion. The discussion of sensitivity and specificity was provided via statistical comparison between the four stages of esophageal cancer. To the best of our knowledge, this is the first study of using these two ratios in combination for staging ESCC.

Nanoparticle-Embedded Electrospun Fiber-Covered Stent to Assist Intraluminal Photodynamic Treatment of Oesophageal Cancer

Drug-eluting stents (DESs) are promising candidates for treating human oesophageal cancer. However, the use of DESs to assist photodynamic therapy (PDT) of orthotopic oesophageal tumors is not yet demonstrated to the best of current knowledge. Herein, through an electrospinning technology it is shown that oxygen-producing manganese dioxide nanoparticles are embedded into elelctrospun fibers, which are subsequently covered onto stents. Upon implantation, the nanoparticles are gradually released from the fibers and then diffuse into the nearby tumor tissue. Then, the hypoxic microenvironment can be effectively alleviated by reaction of MnO₂ with the endogenous H₂ O₂ within the tumor. After demonstrating the excellent PDT efficacy of the stents in a conventional subcutaneous mouse tumor model, such stents are further used for PDT treatment in a rabbit orthotopic oesophageal cancer model by inserting an optical fiber into the tumor site. Greatly prolonged survival of rabbits is observed after such intraluminal PDT treatment. Taken together, this work shows that the fiber-covered stent as a nanoparticle delivery platform can enable effective PDT as a noninvasive treatment method for patients with advanced-stage oesophageal cancer.

A Review of Self-Expanding Esophageal Stents for the Palliation Therapy of Inoperable Esophageal Malignancies

Esophageal cancer is a very deadly disease, killing more than 15,000 people in the United States annually. Almost 400,000 new cases happen in the worldwide every year. More than 50% esophageal cancer patients are diagnosed at an advanced stage when they need an esophageal stent to open the blocked esophagus for feeding and drinking. Esophageal stents have evolved in stages over the years. Current clinically used stents commonly include stainless steel or nitinol self-expandable metallic stent (SEMS) and self-expandable plastic stent (SEPS). There are many choices of different types of stents and sizes, with fierce competition among manufacturers. However, current stent technology, whether uncovered, partially covered, fully covered SEMS or SEPS, has their own advantages to solve the dysphagia, stricture, and fistula problems, but they also cause some clinical complications. The ideal stent remains elusive. New 3D printing technique may bring new promising potential to manufacturing personalized esophageal stents. Drug-eluting stents could be the new avenue to do more than just pry open a stricture or cover a defect in the esophageal lumen, a possibility of proving local anticancer therapy simultaneously. Additionally, the lack of esophageal cancer animal models also hinders the progress of stent development. This paper reviews these topics for a comprehensive understanding of this field. In a conclusion, the ultimate goal of the future esophageal stent would have multifunction to treat the underlying conditions and restore esophageal function to near normal.