02 Dec 2015
Developmental device can inspect and precision treat cancerous cells via minimally-invasive routes.Institute for Basic Science (IBS) has developed a multifunctional endoscope that integrates transparent bioelectronics such as lasers with theranostic (therapeutic-diagnostic) nanoparticles (NPs). The scientists say it opens the door to potential therapies to test new medication and tailor treatments for patients with diseases such as cancer.
The results of the work have just been published in Nature Communications.
Conventional endoscopes, say the researchers, lack the spatial resolution necessary to detect and treat small cancers and other abnormalities. Although these devices are usually equipped with a flexible tube, camera and lighting system, onboard sensors integrated with surgical and other treatment systems are not available because of the relatively large size of conventional systems. This prevents combined diagnosis and therapy of micro-scale tumors.
The IBS team, led by the director of the Center for Nanopaticle Research Professor Taeghwan Hyeon, has now demonstrated a multifunctional surgical endoscope system to diagnose and treat intestinal diseases, such as colon cancers. This smart endoscope system contains transparent bioelectronics, which provides pH-based sensing combined with radio frequency ablation (RFA); and a medical procedure in which a tumor is ablated by heat generated from a medium-frequency alternating current.
The system’s additional sensors for monitoring mechanical contacts and mapping temperatures provide accurate physiological sensing capabilities during cancer detection and ablation. The transparency of the system enables optimal integration of a number of multifunctional sensing and therapeutic components on the endoscope’s tip.
By loading transparent bioelectronics on the camera of the endoscope, the tissue observed through the camera in fluorescence mapping and phototherapies can be exactly matched with the characterized ablated tissues by transparent devices. The system can also deliver biocompatible NPs with phototherapeutic and chemotherapeutic agents, which can then be activated with light.
According to the team’s Nature Communications paper, this multifunctional endoscopic system could be useful for the detection of “flat or depressed abnormal growths”. Synergistic effects between the transparent bioelectronics and theranostic NPs can enhance the accuracy of tumor detection and provide treatment.
Controlled, in vivo laboratory experiments have been performed on mice. The team say the results highlighted the utility of this technology for its accurate detection, delineation and rapid targeted therapy of colon cancer or precancerous lesions. An intravenous injection of NPs was administered to actively target colon cancer cells. Imaging of fluorescence dyes loaded on these NPs provided optical information about the spatial distribution of cancer cells.
The endoscope allowed laser light to access suspicious sites exposed to NPs. These regions were easily observed due to the transparency of the integrated transparent bioelectronics on the endoscope camera. The transparent bioelectronics and associated sensors provided additional electrochemical analysis of the tumor distribution. After a suspicious area of tissue is optically observed and potentially cancerous tissue identified, they can be treated by several modalities.
Direct control of the laser light, which is delivered through an optical fiber and guided with the endoscope, can overcome many issues related to the penetration depth of light. Because colon cancers are normally located in superficial regions, the team’s system is less affected by the penetration depth problem of light in comparison with other tumor cases.
The results of the experiments were significant: after a two-week treatment program, the tumors significantly decreased on the mouse model. However, when tumors were treated without injecting NPs or using chemo-drugs, the tumor volume increased. The combined therapy group exhibited a marked decrease in the tumor volume.
So the IBS team concludes that multifunctional endoscope systems “have the potential to reduce the procedure time and improve the efficiency of minimally invasive surgical procedures for colon cancer treatment. Furthermore, efficient therapy can contribute to the excellent oncologic and economic yield for various gastrointestinal cancers or precancerous lesions in the future.
“Furthermore, efficient therapy can contribute to the excellent oncologic and economic yield for various gastrointestinal cancers or precancerous lesions in the future. These systems facilitate access to internal organs and provide a significant amount of diagnostic feedback during treatment routines, thus highlighting the utility of this technology in the translational medicine.”
About the Author
Matthew Peach is a contributing editor to optics.org.