Laser-activated Polymer Devices for Intracellular Delivery

A challenge in the biomedical field to advancing fundamental studies of biologically interesting molecules for clinical use is the direct delivery into the cytoplasm in an efficient way. Established methods such as electroporation and viral transduction each come with respective strengths and weaknesses that fit different application needs. We present a delivery method that combines 11-ns laser pulses of 1064 nm wavelength and polymer substrates to create transient pores in cells. These polymer devices are are low-cost, biocompatible, and have simple fabrication techniques. Adherent cells are grown on the substrates, and pores only form on the cells in localized regions excited with the laser pulses, allowing spatial selectivity. The medium surrounding the cell contain the cargos, and they diffuse into the cell before the transient pores self-seal. We are able to deliver membrane-impermeable cargos of sizes up to 40 kDa. We obtained efficiencies of up to 40% with viabilities of 60% for calcein green in HeLa and Panc-1 cells. Scanning electron microscopy and optical profilometry are used to study the substrate surface morphology. This laser-activated polymer device can deliver important material directly into cells, furthering the field of nanomedicine in a cost-effective manner.