A Microneedles Balloon Catheter for Endovascular Drug Delivery

Abstract

Disorders of the inner parts of blood vessels have been significant triggers of cardiovascular diseases (CVDs). Different interventional methods have been employed, from complex surgeries to balloon angioplasty techniques to open the narrowed blood vessels. However, CVDs continue to be the lead cause of death in the world. Delivering a therapeutic agent directly to the inner wall of affected blood vessels can be a transformative step toward a better treatment option. To open the door for such an approach, a catheter delivery system is developed based on a conventional balloon catheter where a fluidic channel and microneedles (MNs) are integrated on top of it. This enables precise and localized delivery of therapeutics directly into vessel walls. Customizable MNs are fabricated using a high‐resolution 3D printing technique where MN's height ranges from 100 to 350 µm. The MNs penetration into a synthetic vascular model is investigated with a computerized tomography scan. Ex vivo tests on rabbit aorta confirm the MN‐upgraded balloon catheter's performance on real tissue. Delivery of fluorescent dye is accomplished by injecting it through the fluidic channel and MNs into the aortic tissue. The dye is observed at up to 180 µm of depth, confirming site‐specific endovascular delivery.

Direct laser writing-enabled 3D printing strategies for microfluidic applications

“…7e). 203 Similarly, researchers have manually sealed microfluidic components with a single input and/or output port to mesoscale fluidic tubing, syringe tips, and capillaries, such as microneedles, 204,205 balloon catheters, 206 3D nozzles for droplet generation (Fig. 7f), 207 and microfluidic delivery and sampling components (Fig.…”

“…A critical caveat to the aforementioned reports for DLWprinting millimetre-and submillimetre-scale microfluidic components is that the vast majority of these approaches rely on the use of "Dip-in Laser Lithography (DiLL)" DLW configurations. [202][203][204][205][206][207][208][209][210][211][215][216][217][218][219][221][222][223] In contrast to oil-immersion DLW (Fig. 6), DiLL configurations involve immersing the objective lens directly in the photomaterial (Fig.…”

Recent strategies for improving hemocompatibility and endothelialization of cardiovascular devices and inhibition of intimal hyperplasia

“…[77][78][79] The 3D printing technique can easily tailor the dimensions and geometry of the microneedles to accommodate the targeted tissue and penetration depth. 80 Thus, they can precisely and locally deliver therapeutics directly into vessel walls. They have demonstrated great potential in the field of cardiovascular therapy.…”

3D‐Printed Microinjection Needle Arrays via a Hybrid DLP‐Direct Laser Writing Strategy

“…[53][54][55] For realizing hollow microneedles that are a requisite for microinjection applications, one key challenge inherent to the submicrometer-scale resolution of the DLW-printing volume element (i.e., "voxel") is that it is ill suited for constructing the larger macro-to-microinterfaces (e.g., input ports) required for delivering fluids to the needles. [56,57,92] To avoid the undesirable costs and time associated with fabricating macroto-microinterfaces in their entirety via DLW, [58] researchers have instead DLW-printed hollow singular microneedles (aspect ratios ≈4-5) [59] and MNAs (aspect ratios ≈2-5) [60] as isolated entities, and then used adhesives (e.g., glue) to manually connect the printed components to macroscale fluidic interfaces. Trautmann et al bypassed such protocols by employing a fabrication methodology that combines femtosecond laser irradiation, annealing, grinding, and polishing to produce microchips with external openings, and then DLW-printing truncated coneshaped MNAs (aspect ratios ≈1.3-3) directly onto the chips.…”