Melt Electrowritten In Vitro Radial Device to Study Cell Growth and Migration

Abstract

of these scenarios. [1] Migration is influenced by chemotactic, topographical, and mechanotransductive cues from the extracellular matrix. [2] Moreover, cell migration in the context of cancer metastasis is a complex and important factor for understanding tumor progression. [3] The most aggressive form of a primary brain tumor is glioblastoma multiforme (GBM) which are highly invasive heterogenous tumors with a very low survival rate. [4] Surgical resection and chemo-or radiotherapy is commonly used for patient treatment, however, tumor recurrence is very frequent. Importantly, GBM cells invade and migrate along white matter tracts and brain blood vessels which promote tumor dissemination. [5] Hence, it is critical to understand the basic process of tumor migration and progression in order to develop new therapeutic drugs and treatment regimens. While therapeutic approaches that minimize GBM migration are logical, another approach focuses on guiding these cells away from the tumor into biomaterial reservoirs with the goal to reduce tumor size. [6] This diversional approach is based on the placement of a tube filled with a matrix and oriented substrate that provides topographical guidance cues at the tumor site. This results in the attraction and guidance of migration of GBM cells into the tube, effectively reducing overall tumor size. Therefore, in line with this study and the fact that GBM cells have an affinity for white brain matter and blood vessels, it is important to develop new 3D in vitro cell culture models to determine the optimal matrix composition that drives GBM migration. Novel research methods and tools provide an opportunity to study cell migration during cancer metastasis [7] where loss of cell adhesion from the primary tumor along with increased cell motility and invasion occurs. There is evidence from 3D microfluidic devices and microchips that matrix stiffness influences the migratory and invasive capabilities of tumor cells through the structure characteristics. [8] There have been significant advances to understand the process of cell migration using in vitro models, which are cost effective and easier to use compared to in vivo studies. With existing in vitro assays, cell migration conditions are welldefined with many based on the traditional 2D cell culture methods. [9] While simple to use, they are challenged to recapitulate the 3D in vivo microenvironment.

Melt Electrowriting of Poly(vinylidene Fluoride-Co-Trifluoroethylene)

“…When measuring the fiber diameter of the top and bottom layers of the scaffold (Figure S2B), no significant decrease or increase was observed. When inspecting the turns of the lines within the scaffolds (Figure 3E-F), the jet lag is pulling the fibers at the turns inwards, as previously observed for radial structures printed using medical-grade PCL [33]. Therefore, the position of the fiber changes with the number of layers when the directing of writing is substantially changing.…”

Melt Electrowriting of Amphiphilic Physically Crosslinked Segmented Copolymers

“…The results show that the inter‐layer bonding was improved with the consisting of bisurea and PPO‐PEG‐PPO segments and the increasing printing speed. [ 42 ] The copolymer 4 could not be performed for this test because this copolymer shows an adhesive behavior on the printed surface and could not be removed without damage.…”

Fiber Bridging during Melt Electrowriting of Poly(ε‐Caprolactone) and the Influence of Fiber Diameter and Wall Height

“…The pauses are important to minimize the lag effect on the accuracy of the design. [ 22,23 ] We found that the duration of the pauses is dependent on the fiber diameter: fibers with larger diameter required longer pauses than those with smaller diameter (Table S1, Supporting Information). The two pauses can be optimized to yield the ideal circular shape of the turning loop as presented in Figure 4A.…”