Detecting a secreted gastric cancer biomarker molecule by targeted nanoparticles for real-time diagnostics.

PURPOSE: A real time detection of gastric cancer-associated biomarker molecules in the lumen of the stomach could assist in early detection of this multi-step malignancy. METHODS: Employing α1-antitrypsin precursor (A1AT) as a secreted biomarker model, a platform with immunoassay capabilities, comprising sensing and detecting compartments was developed. It was made of a microarray-type functionalized glass, containing a high density of amine groups. Trypsin, the capturing moiety, was immobilized to the glass surface with the aid of a PEG-based spacer mixture, identified as being crucial for both capturing and detecting properties. The detecting compartment contained near infrared fluorescently labeled nanoparticles conjugated to A1AT-specific antibodies, aimed at generating an optical signal, detectable by a conventional endoscope or a video capsule. RESULTS: The specific recognition reaction between the captured A1AT and the immuno-nanoparticles generated a profound fluorescence with a signal to noise ratio (SNR) of 12-32, in a biomarker-concentration dependent manner. Moreover, the optical recognition signal was intense enough to be detected by a video capsule simulator (with optical detection capabilities of a video capsule) with a SNR of 6-20. CONCLUSIONS: This platform could serve as a real time diagnostic kit for early detection of a secreted biomarker of gastric cancer.

Inspection of the human stomach using remote-controlled capsule endoscopy: a feasibility study in healthy volunteers (with videos).

BACKGROUND: Remote control of capsule endoscopes might allow reliable inspection of the human stomach. OBJECTIVE: To assess the safety and efficacy of manipulation of a modified capsule endoscope with magnetic material (magnetic maneuverable capsule [MMC]) in the human stomach by using a handheld external magnet. DESIGN: Open clinical trial. SETTING: Academic hospital. PATIENTS: Ten healthy volunteers. INTERVENTIONS: Subjects swallowed the MMC and sherbet powder for gastric distention. An external magnetic paddle (EMP-2) was used to manipulate the MMC within the stomach. MMC responsiveness was evaluated on a screen showing the MMC film in real time. MAIN OUTCOME MEASUREMENTS: Safety and tolerability (questionnaire), gastric residence time of the MMC, its responsiveness to the EMP-2, area of gastric mucosa visualized. RESULTS: There were no adverse events. The MMC was always clearly attracted by the EMP-2 and responded to its movements. It remained in the stomach for 39 ± 24 minutes. In 7 subjects, both the cardia and the pylorus were inspected and 75% or more of the gastric mucosa was visualized (≥50% in all of the remaining subjects). A learning curve was clearly recognizable (identification of MMC localization, intended movements). LIMITATIONS: Small amounts of fluid blocked the view of apical parts of the fundus; gastric distention was not sufficient to flatten all gastric folds. CONCLUSIONS: Remote control of the MMC in the stomach of healthy volunteers using a handheld magnet is safe and feasible. Responsiveness of the MMC was excellent, and visualization of the gastric mucosa was good, although not yet complete, in the majority of subjects. The system appeared to be clinically valuable and should be developed further. ( CLINICAL TRIAL REGISTRATION NUMBER: DE/CA05/2009031008.).

Remote magnetic control of a wireless capsule endoscope in the esophagus is safe and feasible: results of a randomized, clinical trial in healthy volunteers.

BACKGROUND: Remote control of esophageal capsule endoscopes could enhance diagnostic accuracy. OBJECTIVE: To assess the safety and efficacy of remote magnetic manipulation of a modified capsule endoscope (magnetic maneuverable capsule [MMC]; Given Imaging Ltd, Yoqneam, Israel) in the esophagus of healthy humans. DESIGN: Randomized, controlled trial. SETTING: Academic hospital. PATIENTS: This study involved 10 healthy volunteers. INTERVENTION: All participants swallowed a conventional capsule (ESO2; Given Imaging) and a capsule endoscope with magnetic material, the MMC, which is activated by a thermal switch, in random order (1 week apart). An external magnetic paddle (EMP; Given Imaging) was used to manipulate the MMC within the esophageal lumen. MMC responsiveness was evaluated on a screen showing the MMC film in real time. MAIN OUTCOME MEASUREMENTS: Safety and tolerability of the procedure (questionnaire), responsiveness of the MMC to the EMP, esophageal transit time, and visualization of the Z-line. RESULTS: No adverse events occurred apart from mild retrosternal pressure (n = 5). The ability to rotate the MMC around its longitudinal axis and to tilt it by defined movements of the EMP was clearly demonstrated in 9 volunteers. Esophageal transit time was highly variable for both capsules (MMC, 111-1514 seconds; ESO2, 47-1474 seconds), but the MMC stayed longer in the esophagus in 8 participants (P < .01). Visualization of the Z-line was more efficient with the ESO2 (inspection of 73% ± 18% of the circumference vs 33% ± 27%, P = .01). LIMITATIONS: Magnetic forces were not strong enough to hold the MMC against peristalsis when the capsule approached the gastroesophageal junction. CONCLUSION: Remote control of the MMC in the esophagus of healthy volunteers is safe and feasible, but higher magnetic forces may be needed.