Nerve regeneration studies should utilize an environment for both surgery and observation that has minimal impacts on biological pathways and behavior. In contrast to the conventional immobilization method using anesthetics, microfluidic devices offer several advantages, including chemical?free immobilization, ease of manipulation, and high throughput data acquisition. These devices provide a wellcontrolled microenvironment for severing axons and monitoring the animals’ neural functions. Specifically for nerve regeneration studies, we developed a new microfluidic device to immobilize the worms for surgery without using any chemicals. This microfluidic device allows us to precisely manipulate worms inside small channels and eliminates the need for anesthetics, which we have shown to interfere with the axonal regrowth process. With the recent advancements in microfluidic interfaces, now it is also feasible to automatically load large sample populations from multiwell plates. The prospective integration and full automation of such microfluidic platforms finally offers the possibility to perform high?throughput, genome?wide screening of phenotypes in living animals.

Plasmonic Laser Nanosurgery (PLN) is a novel photodisruption technique that exploits the large enhancement of femtosecond (fs) laser pulses in the near?field of metal nanoparticles for the selective and non?thermal nanoscale manipulation of biological structures. The electric field, which is amplified when the laser frequency is tuned to the plasmon frequency of a metal nanostructure, can be utilized to initiate photodamage with nanoscale precision to biological targets onto which nanoparticles are attached. The use of fs?laser pulses ensures non?thermal tissue photodisruption, while functionalized nanoparticles greatly improve the localization of the photodisruption process. Moreover, the enhanced electric field around the particle reduces the fluence necessary for material photodisruption, limiting the extent of damage to the particle near?field. Since the particles themselves act as “nano?lenses”, large volumes of tissue can be irradiated at a given time, decreasing the time of treatment. In addition, gold nanostructures exhibit minimal cellular toxicity, making the technique ideal for in vivo clinical use. .

In our own research, we have demonstrated the feasibility of plasmonic laser optoporation for both cellular death by necrosis for cancer treatment and transient pore formation for cellular transfection. In clinical medicine, PLN has the potential to treat cancers localized in sensitive regions, i.e. brain tumor, or can be utilized for the removal of small epithelial cancer lesions, i.e. breast carcinomas in situ. In biological sciences, PLN could bring significant advance in the transfection of cellular systems; this includes the transfection of cells that typically do not respond well to traditional transfection methods or that of in vivo mass transfections. On a broader spectrum, the high specificity of PLN provides the possibility for membrane? and molecular?specific phototherapy; direct therapeutic prospects extend into the fields of cancer, genetics, proteomics, virology, bacteriology, and cardiology.

Specific project: Demonstrate laser surgery at the nano-scale (about 20-50nm).