Christos Boutopoulos

Université de Montréal | UdeM · Department of Ophthalmology

We present a drop-on-demand (DOD) bioprinting method based on a novel implementation of laser-induced side transfer (LIST). Our approach involves continuous bioink perfusion through a glass capillary featuring a laser-machined hole in the capillary wall, serving as a nozzle. Focused low-energy nanosecond laser pulses are employed for precise drople...

Cell bioprinting technologies aim to fabricate tissue-like constructs by delivering biomaterials layer-by-layer. Bioprinted constructs can reduce the use of animals in drug development and hold promise for addressing the shortage of organs for transplants. We recently introduced a laser-assisted drop-on-demand bioprinting technology termed Laser In...

The ability to bioprint microvasculature networks is central for drug screening and for tissue engineering applications. Here we used a newly developed bioprinting technology, termed laser-induced side transfer (LIST), to print human umbilical vein endothelial cells (HUVECs) and to spatially guide endothelial tubulogenesis. We investigated the effe...

Nociceptor Neuron Silencing In article number 2103364, Sebastien Talbot, Christos Boutopoulos, and co‐workers report a nanotechnology‐enabled strategy to silence subsets of unmodified nociceptor neurons. It uses laser stimulation of neurons targeted with gold nanoparticles to heat‐activate TRPV1, turning this channel into a cell‐specific entry port...

The sensory nervous and immune systems work in concert to preserve homeostasis. While this endogenous interplay protects from danger, it may drive chronic pathologies. Currently, genetic engineering of neurons remains the primary approach to interfere selectively with this potentially deleterious interplay. However, such manipulations are not feasi...

We introduced and validated a method to encase guiding optical coherence tomography (OCT) probes into clinically relevant 36G polyimide subretinal injection (SI) cannulas. Modified SI cannulas presented consistent flow capacity and tolerated the typical mechanical stress encountered in clinical use without significant loss of sensitivity. We also d...

Parkinson’s disease (PD) is the second most common neurodegenerative disorder, affecting 1–2% of the population aged 65 and over. Additionally, non-motor symptoms such as pain and gastrointestinal dysregulation are also common in PD. These impairments might stem from a dysregulation within the gut-brain axis that alters immunity and the inflammator...

Purpose: The occurrence of iatrogenic retinal breaks (RB) in pars plana vitrectomy (PPV) is a complication that compromises the overall efficacy of the surgery. A subset of iatrogenic RB occurs when the retina (rather than the vitreous gel) is cut accidentally by the vitrector. We developed a smart vitrector that can detect in real-time potential...

We demonstrate that nanosecond laser-induced bubbles, generated in sealed containers, can experience self-limiting effects. We experimentally study such effects using simultaneous pressure and bubble dynamics recordings. We show that self-limiting effects can be drastic for mm-sized bubbles generated in sub-cm 3 sized containers, resulting in 0.5-f...

Cell bioprinting technologies aim to fabricate tissuelike constructs by delivering biomaterials layer-by-layer. Bioprinted constructs can reduce the use of animals in drug development and hold promise for addressing the shortage of organs for transplants. Here, we sought to validate the feasibility of bioprinting primary adult sensory neurons using...

Validation of a modified version of an NCCA (NCCAm) and comparison with the Cochet Bonnet Aesthesiometer (CBA) in subjects with normal corneas. The NCCA device described by Murphy et al (1996, 1998) to measure corneal sensitivity was modified as follows: The air reservoir was placed outside the enclosure and the fan inside, and a 3-way solenoid val...

We present a 41G subretinal injection cannula integrating a guiding OCT probe. The guiding system includes a micromanipulator and a user-friendly interface. Ex-vivo validation indicated successful guidance of injections in porcine eyes.

We introduced and validated a drop-on-demand method to print cells. The method uses low energy nanosecond laser (wavelength: 532 nm) pulses to generate a transient microbubble at the distal end of a glass microcapillary supplied with bio-ink. Microbubble expansion results in the ejection of a cell-containing micro-jet perpendicular to the irradiati...

We introduced and validated a method to miniaturize graded-index (GRIN) fiber-based optical coherence tomography (OCT) probes down to 70 μm in diameter. The probes consist in an assembly of single-mode (SM), coreless (CL), and graded-index (GRIN) fibers. We opted for a probe design enabling controlled size reduction by hydrogen fluoride etching. Th...

Intracellular delivery of molecular cargo is the basis for a plethora of therapeutic applications, including gene therapy and cancer treatment. A very efficient method to perform intracellular delivery is the photo-activation of nanomaterials that have been previously directed to the cell vicinity and bear releasable molecular cargo. However, poten...

Nanoscale bubbles generated around laser-excited metallic nanoparticles are promising candidates for targeted drug and gene delivery in living cells. The development of new nanomaterials for efficient nanobubble-based therapy is however limited by the lack of reliable computational approaches for the prediction of their size and dynamics, due to th...

Precise spatial and temporal control of pressure stimulation at the nanometer scale is essential for the fabrication and manipulation of nano-objects, and for exploring single-molecule behaviour of matter under extreme conditions. However, state-of-the-art nano-mechanical transducers require sophisticated driving hardware and are currently limited...

Photons interaction with metallic nanoparticles can excite a resonant plasmon that concentrates energy at the nanoscale. At high intensity, this quasi-particle decays into a photo-excited nanoplasma that triggers the generation of nanobubbles, which can be used for imaging and therapeutic purposes. This highly non-linear wavelength-dependent proces...

Gold and silver plasmonic nanoparticles (NPs) are widely used as a contrast agent for photoacoustic (PA) imaging, taking advantage of the strong optical absorption cross-section of these particles due to their localized surface-plasmon resonance. Inspired by recent developments in ultra-high frequency wide-bandwidth transducers, we propose utilizin...

Gold nanoparticles (AuNPs) have found numerous applications in nanomedicine in view of their robustness, ease of functionalization and low toxicity. Upon irradiation of AuNPs by a pulsed ultrafast laser, various highly localized phenomena can be obtained including a temperature rise, pressure wave, charge injection and production of nanobubbles clo...

Metallic nanoparticles are routinely used as nanoscale antenna capable of absorbing and converting photon energy with sub-wavelength resolution. Many applications, notably in nanomedicine and nanobiotechnology, benefit from the enhanced optical properties of these materials, which can be exploited to image, damage or destroy targeted cells and sub-...

Selective targeting of diseased cells can increase therapeutic efficacy and limit off-target adverse effects. We developed a new tool to selectively perforate living cells with functionalized gold nanoparticles (AuNPs) and near-infrared (NIR) femtosecond (fs) laser. The receptor CD44 strongly expressed by cancer stem cells was used as a model for s...

We report on transient membrane perforation of living cancer cells using plasmonic gold nanoparticles (AuNPs) enhanced single near infrared (NIR) femtosecond (fs) laser pulse. Under optimized laser energy fluence, single pulse treatment (τ = 45 fs, λ = 800 nm) resulted in 77% cell perforation efficiency and 90% cell viability. Using dark field and...

Plasmonic nanoparticles can lead to extreme confinement of the light in the near field. This unique ability of plasmonic nanoparticles can be used to generate nanobubbles in liquid. In this work, we demonstrate with single-particle monitoring that 100 nm gold nanoparticles (AuNPs) irradiated by off-resonance femtosecond (fs) laser in the tissue the...

Plasmonic enhanced ultrafast laser-induced cell nanosurgery

Laser-triggered gold nanoparticle-assisted cell poration for selective gene delivery

Plasmonic enhanced ultrafast laser-induced cell nanosurgery

Laser-triggered gold nanoparticle-assisted cell poration for selective gene delivery

In this work, we present the generation of high velocity liquid jets of a photosynthetic biomaterial in buffer solution (i.e. thylakoid membranes) and a test solution, using the laser-induced forward transfer (LIFT) technique. The high impact pressure of the collision of the jets on solid substrates, ranging from 0.045 MPa–35 MPa, resulted in stron...

Femtosecond (fs) laser generation of submicron bubbles around plasmonic nanoparticles (NPs) plays a key role in advanced laser nanosurgery applications such as cell membrane perforation and cell transfection. In this context, we have developed a pump-probe shadowgraphic ultrafast imaging technique capable of tracking transient bubbles generated by...

Liquid jets created by the Laser Induced Forward Transfer (LIFT) technique can reach extremely high speeds exceeding 270 m/s. The impact of such a jet on a solid surface can create a dynamic pressure of 35 MPa, enabling the LIFT process to stick liquid droplets on highly slippery superhydrophobic surfaces. In this letter, we demonstrate how LIFT pr...

The development of organic electronic requires a non contact digital printing process. The European funded e-LIFT project investigated the possibility of using the Laser Induced Forward Transfer (LIFT) technique to address this field of applications. This process has been optimized for the deposition of functional organic and inorganic materials in...

In this work, we used time-resolved imaging to study the dynamics of the laser-induced forward transfer (LIFT) process of a silver nanoparticle (NP) ink (NP size: 30–50 nm). LIFT is a versatile direct write technique in which a variety of functional materials can be transferred from a donor substrate to a receiving substrate with high spatial resol...

Applied Surface Science j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / a p s u s c a b s t r a c t The dynamics of liquid phase laser induced forward transfer (LIFT) of silver nanoparticle (NP) ink (particle size 30–50 nm) was investigated by time-resolved shadowgraphic imaging. LIFT was carried out by a KrF excimer...

A method for direct immobilization of biomolecules onto rough solid substrates by means of laser transfer is enclosed. The method involves the use of laser pulses for transferring biomolecules from a donor substrate onto the opposite positioned rough surface of a receiving substrate. The high kinetic energy of the transferred biomaterials enhances...

One of the limits of current electrochemical biosensors is a lack of methods providing stable and highly efficient junctions between biomaterial and solid-state devices. This paper shows how laser-induced forward transfer (LIFT) can enable efficient electron transfer from photosynthetic biomaterial immobilized on screen-printed electrodes (SPE). Th...

The growing interest in personalized medicine leads to the need for fast, cheap and portable devices that reveal the genetic profile easily and accurately. To this direction, several ideas to avoid the classical methods of diagnosis and treatment through miniaturized and label-free systems have emerged. Capacitive biosensors address these requireme...

a b s t r a c t The evaluation of a capacitive type biosensor array, consisting of a total of 256 biosensing elements, in the detection of single oligonucleotide mutations is presented. The biosensor takes advantage of surface stress changes during biological interactions and is able to translate them into a capacitive signal. The array is organize...

a zergioti@central.ntua.gr Abstract: This work presents the direct laser printing of thylakoid membranes for the fabrication of photosynthetic-based amperometric biosensors. Laser printing is an excellent tool for direct immobilization of the transferred photosynthetic material onto non-functionalized electrodes due to the high impact pressure of t...

This letter demonstrates the direct laser printing of photosynthetic material onto low cost nonfunctionalized screen printed electrodes for the fabrication of photosynthesis-based amperometric biosensors. The high kinetic energy of the transferred material induces direct immobilization of the thylakoids onto the electrodes without the use of linker...

The detection of DNA hybridization using capacitive readout and a biosensor array of ultrathin Si membranes is presented. The biosensor exploits the ability of the ultrathin membranes to deflect upon surface stress variations caused by biological interactions. Probe DNA molecules are immobilized on the membrane surface and the surface stress variat...

Investigations of the sensitivity and selectivity of a capacitive type biosensor array, consisting of a total of 256 biosensing elements, in the detection of single oligonucleotide mutations is presented. The biosensor takes advantage of surface stress changes during biological interactions and is able to translate them into a capacitive signal. Th...

The fabrication of chemical sensor arrays using laser induced forward transfer (LIFT) as a means to deposit polymer layers to be used as chemically sensitive material is presented. LIFT is a direct, maskless technique offering high spatial resolution printing of a wide range of polymers and in this work it has been applied in the fabrication of a c...

Direct and high spatial resolution printing of polymer/carbon nanotube (CNT) composite layers has been demonstrated by means of laser induced forward transfer (LIFT). Laser irradiation of composite target materials, such as poly(acrylic acid)/CNT and polyvinylpyrrolidone/CNT, enabled dry deposition of well resolved composite pixels onto glass subst...

a b s t r a c t The detection of the biotin–streptavidin interaction is presented based on surface stress changes of func-tionalized Si membranes. During the biomolecular interaction, the surface stress of the functionalized membranes alters resulting in their deflection and finally in capacitance variations. The biological inter-action on the sens...

A biosensor which takes advantage of surface stress changes during biological interactions and is able to translate them into a capacitive signal is presented. The sensor consists of an ultrathin silicon membrane on which receptor molecules are immobilized. During biomolecular interactions, the surface stress changes and the membrane deflects resul...

This letter demonstrates the direct laser printing of polymers on capacitive micromechanical arrays for the realization of a chemical sensor. Each sensor of a single chip array is composed of a thin Si membrane covered by a chemically sensitive polymer layer by means of a direct laser printing technique. We present the high spatial resolution depos...

Laser Induced Forward Transfer (LIFT) technique is a direct-write method allowing the effective deposition of a wide range of materials with high spatial resolution. In this work, we present the direct printing of microarrays from a biotin solution by using a Nd:YAG laser (266 nm wavelength, 4ns pulse duration). Standard materials of microelectroni...

Pulsed-laser-based methods have been applied for post-implant annealing of p-type Al-doped 4H–SiC wafers in order to restore the crystal structure and to electrically activate the doping species. The annealing was performed with the third harmonic (355nm) of a Nd:YAG laser at 4ns pulse duration. The epilayers were characterized by micro-Raman spect...

Pulsed-laser-based methods have been applied for post-implant annealing of p-type Al doped 4H-SiC wafers in order to restore the crystal structure and to electrically activate the doping species. The annealing was performed with the second (532nm) and third (355nm) harmonic of a Nd:YAG laser at 4ns pulse duration. The epilayers were characterized b...