Multi-layered electrospinning and electrospraying approach: Effect of polymeric supplements on chondrocyte suspension

Abstract

Articular cartilage was expected to be one of the first tissues to be successfully engineered, but replicating the complex fibril architecture and the cellular distribution of the native cartilage has proven difficult. While electrospinning has been widely used to reproduce the depth-dependent fibre architecture in 3D scaffolds, the chondrocyte-controlled distribution remains an unsolved problem. To incorporate cells homogeneously through the depth of scaffolds, a combination of polymer electrospinning and cell seeding is necessary. A multi-layer approach alternating between polymer electrospinning with chondrocyte electrospraying can be a solution. Still, the success of this process is related to the survival rate of the electrosprayed chondrocytes embedded within the electrospun mesh. In this regard, the present study investigated the impact of the multi-layered process and the supplementation of the electrospray chondrocyte suspension with different concentrations of Gelatin and Alginate on the viability of electrosprayed chondrocytes embedded within a Polycaprolactone/Gelatin electrospun mesh and on the mechanical properties of the resulting meshes. The addition of Gelatin in the chondrocyte suspension did not increase significantly ( p > 0.05) the percentage of viable electrosprayed chondrocytes (25%), while 3 wt% Alginate addition led to a significant ( p < 0.05) increase in chondrocyte viability (50%) relative to the case without polymer supplement (15%). Furthermore, the addition of both polymer supplements increased the mechanical properties of the multi-layer construct. These findings imply that this multi-layered approach can be applied to cartilage TE allowing for automated chondrocyte integration during scaffolds creation.

Fabrication of Customizable and Reproducible 3D Chondrocyte-Laden Nanofibrous Architectures: Effect of Specific Fiber Alignments and Porosities on Chondrocyte Response under Cyclic Compression

“…10,45 Nonetheless, prior work has shown that combining the chondrocyte suspension with a polymeric hydrogel such as ALG was highly efficient in preventing cell death in this instance. 22 Indeed, a substantial percentage of chondrocytes was viable after 24 h of the fabrication process, particularly on the PG_D360. This metabolic behavior persisted and intensified during the course of 21 days in culture.…”

“…Three distinct scaffold architectures with controlled fiber alignment and porosity were fabricated with specific programmed fiber placements and characterized in terms of topography, water absorption capacity, and mechanical behavior. Similar to previous reports, 10,22,25,45 a cellular microintegration approach was also used in this work to seed cells directly onto the fibrous layers during scaffold's fabrication to obtain cell-laden constructs with a homogeneous cellular distribution. Chondrocytes were selected as the cell model, at this point, due to their low proliferative rate, and their subsequent difficulty in fully colonizing a 3D scaffold.…”

“…Concerning three-dimensionality, considerable efforts have been made to develop or modify existing electrospinning setups in order to obtain 3D nanofibrous structures, such as self-assembly, , template- , and liquid-assisted collection, , postprocessing after electrospinning, , and multilayered electrospinning, , among others. Despite the substantial progress reported using these strategies, it is still a challenge to fabricate highly reproducible 3D electrospun scaffolds with controlled macro- and microporosity because of (1) the difficulty in precisely controlling the final 3D shape, particularly in self-assembled, wet-electrospun, gas-expanded, and manually processed scaffolds ,− or (2) the need for customized collectors to control the shape and structure of template-assisted-based scaffolds. , In this regard, multilayer electrospinning emerges as an approach with a higher degree of flexibility in the control of composition, fiber arrangement, porosity, pore size, and interconnectivity, depending on each layer’s features .…”

“…Despite the substantial progress reported using these strategies, it is still a challenge to fabricate highly reproducible 3D electrospun scaffolds with controlled macro- and microporosity because of (1) the difficulty in precisely controlling the final 3D shape, particularly in self-assembled, wet-electrospun, gas-expanded, and manually processed scaffolds ,− or (2) the need for customized collectors to control the shape and structure of template-assisted-based scaffolds. , In this regard, multilayer electrospinning emerges as an approach with a higher degree of flexibility in the control of composition, fiber arrangement, porosity, pore size, and interconnectivity, depending on each layer’s features . Furthermore, it can combine nanofibrous, 3D-printed, electrosprayed, and cell layers in a single construct. ,, …”

Novel In Situ-Cross-Linked Electrospun Gelatin/Hydroxyapatite Nonwoven Scaffolds Prove Suitable for Periodontal Tissue Engineering

“…Multifunctional composite materials that consist of different components can be fabricated reliably at the nanometer scale [43][44][45][46]. Because of its many advantages, electrospinning has already been experimentally applied to bone [47,48], cartilage [49,50], tendon/ligament [51,52], skin [53,54], and cardiovascular [55,56] tissue engineering, as well as for wound dressings [57][58][59]. To date, however, no FDA-approved electrospun regenerative tissue engineering biomaterial is available commercially [42].…”