Optics in the Life Sciences
- 14 - 18 April 2013
Waikoloa Beach Marriott Resort and Spa, Waikoloa Beach, Hawaii, USA
Significant advances in the development of optical techniques have led to an ever increasing role of optics in the study of and treatment of various problems in the life sciences ranging from molecular level investigations to clinical treatment of patients. In this Congress, the latest advances in molecular probe development, life science imaging, novel and more powerful optical instrumentation and its application to study fundamental biological processes and clinical investigations will be presented. This progress in instrumentation development and its rapid application represents important enablers that permit studies not possible a few years ago. The upcoming group of meetings is a forum designed to report on this progress and brings together leaders in the field whose contributions are significantly advancing the state of the art in biological and medical research through the use of optical technologies.
Strong Attendance and Innovative Technologies Mark The OSA 2013 Optics in Life Science Congress
Snorkeling, glass bottom boats and a luau were just part of the fun enjoyed by attendees of the Optics in Life Sciences Congress in Hawaii April 14-18. The meeting, which included four co-located meetings—Optical Trapping Applications (OTA), Novel Techniques in Microscopy (NTM), Bio-Optics Design and Application (BODA), and Optical Molecular Probes, Imaging and Drug Delivery (OMP) featured outstanding presentations on a range of novel optical techniques for biomedical applications.
With a generous amount of time allotted for individual meetings, the Congress’s joint sessions—the plenary, a special symposium “Photons Across Medicine,” and BODA’s combined sessions with OTA and OMP—demonstrated the importance of interdisciplinary collaboration. The plenary session featuring talks by Elizabeth Hillman (Columbia University) and Duco Jansen (Vanderbilt University) offered a look at current research on optical techniques for brain imaging. “These talks were very timely and a great way to kick off the congress,” says Adam Wax, chair of OSA’s Bio-medical Optics Division. The session came just days after the White House announced a $100 million BRAIN Initiative aimed improving brain research through innovative neurotechnologies. The session also included a talk by microscopy pioneer Sunney Xie (Harvard University) who described recent advances in stimulated Raman microscopy, a label-free imaging technique that uses vibrational spectroscopy for contrast.
The “Photons Across Medicine” symposium, which resulted from a partnership between OSA and the Society of Nuclear Medicine and Molecular Imaging, was very well attended and “not the usual thing at an OSA meeting,” says Wax. The National Institutes of Health’s Robert Nordstrom moderated the session which highlighted progress in developing molecular imaging agents and instrumentation for clinical applications. Optical molecular probe pioneer Eva Sevick-Muraca (University of Texas Health Science Center at Houston) discussed ways to quantify how well near-infrared fluorescence imaging detects cancer margins during surgery. Simon Cherry (University of California, Davis) followed and described the convergence of photonic-based technologies with nuclear imaging modalities while Ali Azhdarina covered hybrid imaging agent development for combined optical/nuclear imaging.
The session concluded with Henry VanBrocklin (University of California, San Francisco) offering insights into the developmental and regulatory challenges nuclear medicine faced in trying to become a clinical modality. One of the critical aspects of converting a promising research technique into a clinical tool is the clinical trial. For a company to support a trial, VanBrocklin noted that the technique would need to offer unique capabilities and be used in 200,000 to 300,000 procedures a year. This translates roughly into peak annual sales of $100 to 150 million. “This talk provided an illustrative example for optical imaging technologies as they move into the clinic,” says Wax.
Deeper, clearer, smaller
Key trends running throughout the congress’s four meetings related to methods to handle scattering to improve deep tissue imaging, approaches to modulate signals as they enter and return from a sample, ways to modify tissue to make it more transparent and efforts to use scattering as an advantage such as wavefront conditioning.
The packed BODA/OTA session featured talks on methods to manipulate quantum dots, single-cell organisms, and proteins. “There was a lot of cross over with microscopy and imaging tissue properties,” says OTA co-chair Carlos Lopez-Mariscal. Using a combination of adaptive optics and a 3D holographic optical trapping microscope, Yael Roichman (Tel Aviv University) described positioning quantum dots within 40 nm of each to make photonic waveguides. Alexander Rohrbach (University of Freiburg) discussed tracking ultra-small bacteria as they propel themselves along using a time-multiplexed optical trap and super-resolution imaging. Ana Zehtabi-Oskuie and Reuven Gordon (University of Victoria) explained trapping a protein and antibody with a microfluidically integrated nanoaperture. “This pushes the scale of the size of items an optical trap can handle,” says Lopez-Mariscal.
The session also featured an elegant approach to using scattering to image an object. Allard Mosk (University of Twente) described how a speckle pattern help generate an image. Passing laser light moves through a diffuser to an object causing it to fluoresce. The excitation signal returns through the scattering layer and is detected. By adjusting the beam and scanning the overlap between the excitation speckle pattern and the object, Mosk can measure the intensity and then extract an image from the autocorrelate.
A variety of new trapping methods were also described in a session on interdisciplinary trapping. Ultrasound arrays are becoming a popular technology of choice to hold and manipulate particles. “Ultrasound tweezers open up a number of pathways of study,” says Lopez-Mariscal. “We’ll see a lot more of this kind of work in the future.” Another unique approach is the use of magnetic tweezers. Megan Valentine (Stanford University) has applied NdFeB-based magnetic tweezers to micron-scale particles for materials characterization. Lopez-Mariscal anticipates magnetic tweezers will “compete strongly with optical tweezers” in coming years.
As optical probes continue to evolve into clinically applicable imaging technologies, their ability to illuminate ever-smaller structures will aid disease diagnosis and treatment, especially cancer detection. Adam Wax (Duke University) described combining plasmonic nanoparticles with low-coherence interferometry to image the structure of sub-cellular organelles and components of epithelial tissue. This work may aid in early cancer detection. Another promising avenue for optical probes is their application during surgery to determine the margins of brain tumors. Kevin Seekell (Duke University) discussed his group’s research on gold nanorods in the near-infrared to help distinguish glioblastomas from normal brain tissue. Brian Applegate (Texas A&M University) explained how his group uses pump probe optical coherence tomography for label-free delineation of malignant and benign lesions.
“The best of both worlds”
Although nonlinear optical microscopy has a strong history, several new approaches are extending the reach of this imaging technique. Several groups are combining photoacoustic and optical techniques to go deeper into tissue and obtain molecular information.”This approach gives the best of both worlds,” says NTM co-chair Eric Potma. Other groups are exploring new contrast mechanisms. Rather than rely on color signals, Martin Fisher (Duke University) and colleagues are studying molecules that don’t fluoresce but do absorb. They have focused on shaping ultrafast laser pulses to visualize nonlinear signatures from tissue and are applying their technique to detect different types of melanin in human skin.
Goro Mizutuani (Japan Advanced Institute of Science and Technology) reported on a spectroscopy sensitive imaging technique that combines infrared light to excite molecular vibrations and visible light to probe the excited sample. Tung Yuen Lau (Kimani group, University of Illinois at Urbana-Champaign) is using second harmonic generation (SHG) to map the orientation of collagen in tissue. Using interferometric SHG microscopy, Francois Legare’s group is imaging tendon and muscle samples. The technique can detect the polar orientation of collagen molecules.
“People have been looking at collagen for a long time. They get great signals but it’s not clear what they mean,” says Potma. “These results, which haven’t been seen before, provide information about the actual structure of collagen that begins to explain which area give rise to the signals.” Shuo Tang (University of British Columbia) has combined multiphoton microscopy and optical coherence tomography to obtain both molecular information and characterize tissue morphology.
From bench to bedside
The OLS meeting demonstrated the great progress made in translating optical techniques from the lab to the clinic, but also pinpointed key technical hurdles that some technologies must still overcome. Perhaps one of the biggest challenges is not technical. “Many academic researchers look for the best technology but don’t consider the costs [of commercialization],” explains BODA chair Ron Liang. By fostering a greater understanding of how industry develops products, Liang hopes future meetings will help researchers shift their focus slightly so that the time to market decreases. He anticipates adding a industry committee for OLS 2015 to develop more “how-to” programming.
Aloha OLS 2013. Mark your calendars for BioMed 2014 in Miami.