Controlled Cell Alignment Using Two‐Photon Direct Laser Writing‐Patterned Hydrogels in 2D and 3D

Abstract

Direct laser writing (DLW) via two‐photon polymerization is an emerging highly precise technique for the fabrication of intricate cellular scaffolds. Despite recent progress in using two‐photon‐polymerized scaffolds to probe fundamental cell behaviors, new methods to direct and modulate microscale cell alignment and selective cell adhesion using two‐photon‐polymerized microstructures are of keen interest. Here, a DLW‐fabricated 2D and 3D hydrogel microstructures, with alternating soft and stiff regions, for precisely controlled cell alignment are reported. The use of both cell‐adhesive and cell‐repellent hydrogels allows selective adhesion and alignment of human mesenchymal stem cells within the printed structure. Importantly, DLW patterning enables cell alignment on flat surfaces as well as irregular and curved 3D microstructures, which are otherwise challenging to pattern with cells.

From the Matrix to the Nucleus and Back: Mechanobiology in the Light of Health, Pathologies, and Regeneration of Oral Periodontal Tissues

“…This enables researchers to generate a broad variety of biomaterials with complex 3D nanotopographies. Other possibilities for scaffold preparation include freeze-drying, electrospinning, or 3D printing [387]. Consequently, cell behavior changes upon contact with the material in response to the geometry and physical properties.…”

“…Therefore, this technique offers the possibility for 3D spatial control of cell behavior [388]. Controlled cell-alignment, which is important for tissue organization, especially in complex composite organs such as the periodontium, is also achievable on such substrates [387]. By using materials with varying matrix stiffnesses, an effect called durotaxis can be observed, meaning that cells migrate from softer to stiffer regions.…”

Visible-Light Stiffness Patterning of GelMA Hydrogels Towards In Vitro Scar Tissue Models

“…Photopatterning, or photolithography, is another method for patterning the stiffness of hydrogels by spatially varying the light irradiance. Photopatterning can be performed in a straightforward manner by using a physical photomask ( Rape et al, 2015 ; Tomba and Villard, 2015 ; Kim et al, 2020 ; Li and Bratlie, 2021 ; Mgharbel et al, 2022 ), via direct laser writing ( Song et al, 2021 ; Jagiełło et al, 2022 ), or by spatially varying the light source itself ( Norris et al, 2016 ; Oh et al, 2022 ). The latter can be achieved using digital micromirror devices (DMDs), such as those contained in some video projectors.…”

Unraveling the Mechanisms Governing Anisotropy in Accordion‐Shaped Honeycomb Microlattice Fabricated by Two‐Photon Polymerization

“…[18][19][20][21] Such scaffolds should be able to guide and support contracting cardiomyocytes. [22][23][24] We sought to fabricate scaffolds that mimic cardiac anisotropy with sub-micrometer control over structural features and mechanical characteristics. Accordion-like honeycomb architecture, which comprises high-aspect-ratio unit cells, has attracted attention for inducing mechanical anisotropy.…”