Light-induced Hyperthermia for oncology and disinfection
Speaker: Prof. Romain Quidant (ICFO)
Recent years have witnessed a growing interest in controlling temperature on the nanoscale motivated by applications to different fields, including information technology, chemistry and medicine. Under illumination at its plasmon resonance, a metal nanoparticle features enhanced light absorption, acting as an ideal nano-source of heat, remotely controllable by light. Such a powerful and flexible photothermal scheme sets the basis of the emerging and fast-growing field of thermoplasmonics. In this talk, we first briefly present the specificities of heat generation in metal nanoparticles compared to standard macroscopic heating. We then focus on two different biomedical applications, namely less-invasive cancer treatment and disinfection of surgical implants.
In the first application, PEG-coated gold nanorods (PEG-GNRs) are tail-injected into an orthoxenograph mouse model of clear cell renal cell carcinoma. Due to their small size, PEG-GNRs can penetrate through the leaky tumor neovasculatures and eventually accumulate in the cancer tissue. This accumulation is non-invasively monitored over time using diffuse optics. Local hyperthermia is then locally induced upon a suitable NIR laser illumination. We study the nature of the cancer tissue damage and demonstrate tumor shrinking.
The second application relates to the prevention of biofilm formation at the surface of surgical implants. In our experiment, a surgical mesh, used for hernia surgery, is coated with a high density of GNRs. We demonstrate that under suitable illumination parameters, bacteria adhesion is reduced preventing the biofilm to form.
On-a-chip Biosensing with optical nanoresonators
Optical biosensing based on optical nanoresonators, either dielectric or metallic, potentially offers great opportunities for compact, sensitive and low-cost diagnostic devices. While last two decades have witnessed the emergence of a diversity of nano-optical systems with outstanding sensitivities, their implementation into real analytical platforms, fulfilling biological samples requirements, is only at its infancy. In this context, we present here our latest advances in the development of on-a-chip nanooptical biosensing devices.
We first demonstrate the capability of our platform to detect clinically relevant concentrations of protein cancer markers in human serum with low unspecific binding and high repeatability. Our design, based on plasmonic nanoresonators integrated into a state-of-the-art microfluidic chip, enables to simultaneously determine the absolute concentration of four different target molecules from an unknown serum sample. The system is validated in the framework of breast cancer, as a potential strategy to monitor cancer activity and assess the risk for brain metastasis.
Next, we explore how the unique optical properties of all dielectric nano-resonators can contribute to molecular biosensing. We discuss the pros and cons of silicon nanostructures over their metallic counterpart and perform a direct comparison of their sensing performance for the detection of proteins markers in human serum.
Finally, in the last part of the talk, we discuss the use of optical nano-antennas for on-a-chip chiral sensing. We present different configuration where nanoptical resonators can be engineered to reliably discern between two molecular enantiomers.