Delivery of Foreign Materials into Adherent Cells by Gold Nanoparticle-Mediated Photoporation

A mini-review on gene delivery technique using nanoparticles-mediated photoporation induced by nanosecond pulsed laser

Nanosecond pulsed laser induced photoporation has gained increasing attention from scholars as an effective method for delivering the membrane-impermeable extracellular materials into living cells. Compared with femtosecond laser, nanosecond laser has the advantage of high throughput and low costs. It also has a higher delivery efficiency than continuous wave laser. Here, we provide an extensive overview of current status of nanosecond pulsed laser induced photoporation, covering the photoporation mechanism as well as various factors that impact the delivery efficiency of photoporation. Additionally, we discuss various techniques for achieving photoporation, such as direct photoporation, nanoparticles-mediated photoporation and plasmonic substrates mediated photoporation. Among these techniques, nanoparticles-mediated photoporation is the most promising approach for potential clinical application. Studies have already been reported to safely destruct the vitreous opacities in vivo by nanosecond laser induced vapor nanobubble. Finally, we discuss the potential of nanosecond laser induced phototoporation for future clinical applications, particularly in the areas of skin and ophthalmic pathologies. We hope this review can inspire scientists to further improve nanosecond laser induced photoporation and facilitate its eventual clinical application.

Microfluidic device-fabricated spiky nano-burflower shape gold nanomaterials facilitate large biomolecule delivery into cells using infrared light pulses

Photothermal nanoparticle-sensitised photoporation is an emerging approach, which is considered an efficient tool for the intracellular delivery of biomolecules. Nevertheless, using this method to achieve high transfection efficiency generally compromises cell viability and uneven distribution of nanoparticles results in non-uniform delivery. Here, we show that high aspect ratio gold nano-burflowers, synthesised in a microfluidic device, facilitate highly efficient small to very-large cargo delivery uniformly using infrared light pulses without sacrificing cell viability. By precisely controlling the flow rates of shaping reagent and reducing agent, high-density (24 numbers) sharply branched spikes (∼80 nm tip-to-tip length) of higher aspect ratios (∼6.5) with a small core diameter (∼45 nm) were synthesised. As produced gold burflower-shape nanoparticles are biocompatible, colloidally stable (large surface zeta potential value), and uniform in morphology with a higher plasmonic peak (max. 890 nm). Theoretical analysis revealed that spikes on the nanoparticles generate a higher electromagnetic field enhancement upon interaction with light pulses. It induces plasmonic nanobubbles in the vicinity of the cells, followed by pore formation on the membrane leading to diverse biomolecular delivery into cells. Our platform has been successfully implemented for uniform delivery of small to very large biomolecules, including siRNA (20-24 bp), plasmid DNA expressing green fluorescent protein (6.2 kbp), Cas-9 plasmid (9.3 kbp), and β-galactosidase enzyme (465 kDa) into diverse mammalian cells with high transfection efficiency and cell viability. For very large biomolecules such as enzymes, the best results were achieved as ∼100% transfection efficiency and ∼100% cell viability in SiHa cells. Together, our findings demonstrate that the spiky gold nano-burflower shape nanoparticles manufactured in a microfluidic system exhibited excellent plasmonic behaviour and could serve as an effective tool in manipulating cell physiology.

Nanomaterial-mediated photoporation for intracellular delivery

Translocation of extrinsic molecules into living cells is becoming increasingly crucial in biological studies ranging from cell engineering to biomedical applications. The concerns regarding biosafety and immunogenicity for conventional vectors and physical methods yet challenge effective intracellular delivery. Here, we begin with an overview of approaches for trans-membrane delivery up to now. These methods are featured with a relatively mature application but usually encounter low cell survival. Our review then proposes an advanced application for nanomaterial-sensitized photoporation triggered with a laser. We cover the mechanisms, procedures, and outcomes of photoporation-induced intracellular delivery with a highlight on its versatility to different living cells. We hope the review discussed here encourages researchers to further improvement and applications for photoporation-induced intracellular delivery. STATEMENT OF SIGNIFICANCE.