Optical transfection using an endoscope-like system

Abstract

Optical transfection is a powerful method for targeted delivery of therapeutic agents to biological cells. A tightly focused pulsed laser beam may transiently change the permeability of a cell membrane to facilitate the delivery of foreign genetic material into cells. We report the first realization of an endoscope-like integrated system for optical transfection. An imaging fiber (coherent optical fiber bundle) with ∼ 6000 cores (pixels) embedded in a fiber cladding of ∼ 300 μm in diameter, produces an image circle (area) of ∼ 270 μm diam. This imaging fiber, with an ordered axicon lens array chemically etched at its exit face, is used for the delivery of a femtosecond laser to the cell membrane for optical transfection along with subcellular resolution imaging. A microcapillary-based microfluidic system for localized drug delivery was also combined in this miniature, flexible system. Using this novel system, a plasmid transfection efficiency up to ∼ 72% was obtained for CHO-K1 cells. This endoscope-like system opens a range of exciting applications, in particular, in the targeted in vivo optical microsurgery area.

Characterization of the cellular response triggered by gold nanoparticle–mediated laser manipulation

“…2 Femtosecond single-cell laser transfection is reviewed in detail by Stevenson et al 3 Further, several experimental settings based on femtosecond laser transfection were evaluated, including the application of femtosecond laser pulses via endoscopic systems, the use of a spatial light modulator to specifically target cells, or microfluidic platforms to enhance the throughput of the method. [8][9][10] Although single-cell laser transfection is well suited to follow individual cells' fates after transfection, the technique does not allow to transfect a high cell number in reasonably short time scales. However, high efficiencies are required in high-throughput screening of pharmaceutically or therapeutically active compounds or to manipulate high cell numbers for cell reconstructive therapies.…”

Characterization of nanoparticle mediated laser transfection by femtosecond laser pulses for applications in molecular medicine

“…a high penetration depth and the avoidance of photo thermal effects) indicate the great potential of fs laser for in vivo manipulation. Furthermore the development of endoscopic systems for ultrafast laser microsurgery [ 45 ] or fiber based approaches [ 46 ] makes the application of ultrashort laser pulses potentially suitable for fs laser in vivo cell manipulation. Additionally, first in vivo experiments showed the generation of nanobubbles around AuNP clusters for selective cancer cell killing using short, 780 nm laser pulses [ 47 ].…”

Cell Signaling Experiments Driven by Optical Manipulation

“…Recently, photoporation was used to introduce biomolecules into the cells of living animals, thus providing an alternative to genetic manipulation of developing embryos via functional modulation of individual cells under sterile conditions [99]. To achieve single-cell photoporation in thick non-transparent tissues, the use of optical fibers in conjunction with a miniaturized microfluidic system for localized drug delivery has been proposed, paving the way for the clinical application of this nanosurgical tool [15]. However, the microfluidic system requires a considerable number of molecules and does not allow control over the number of delivered factors.…”

“…The use of laser microsurgery in cell and developmental biology was introduced during the same period as OT as a result of investigations into the potential applications of lasers [14]. The laser microsurgery technique has evolved in parallel with that of OT [15], and it can be implemented jointly with optical trapping on the same microscope platform for single-cell signaling experiments.…”