A Bioinspired Ultraporous Nanofiber‐Hydrogel Mimic of the Cartilage Extracellular Matrix

Abstract

A true biomimetic of the cartilage extracellular matrix (ECM) could greatly contribute to our ability to regenerate this tissue in a mechanically demanding, often inflamed environment. Articular cartilage is a composite tissue made of cells and fibrillar proteins embedded in a hydrophilic polymeric meshwork. Here, a polyanionic functionalized alginate is used to mimic the glycosaminoglycan component of the native ECM. To create the fibrillar component, cryoelectrospinning of poly(ε-caprolactone) on a -78 °C mandrel, subsequently treated by O plasma, is used to create a stable, ultraporous and hydrophillic nanofiber network. In this study, cell-laden, fiber-reinforced composite scaffolds thicker than 1.5 mm can be created by infiltrating a chondrocyte/alginate solution into the fiber mesh, which is then physically cross-linked. The fibrillar component significantly reinforces the chondroinductive, but mechanically weak sulfated alginate hydrogels. This allows the production of a glycosaminoglycan- and collagen type II-rich matrix by the chondrocytes as well as survival of the composite in vivo. To further enhance the system, the electrospun component is loaded with dexamethasone, which protected the cells from an IL-1β-mediated inflammatory insult.

Low-cost FDM 3D-printed modular electrospray/electrospinning setup for biomedical applications

“…Electrospinning is a widely used method for pharmaceutical, medicinal or biological applications [9][10][11][12] as it can process solutions, melts, or even suspensions into long nano/micro-fibers [13]. It is the only technique for scaling up continuous nanofiber production [14].…”

Polymer Fiber Scaffolds for Bone and Cartilage Tissue Engineering

“…Formica et al used polyanionic‐functionalized alginate to mimic the glycosaminoglycan components in the natural ECM. A stable network of superporous hydrophilic nanofibers was established by cryoelectrospinning PCL on a mandrel at −78 °C and subsequently treating it with O 2 plasma . The authors designed a biomimetic hybrid chondrogenic hydrogel and super porous electrospun polymer film, where the functionality of the alginate sulfate was realized by low‐temperature electrospinning and drug‐loaded porous PCL scaffolds.…”

“…Preparation and mechanism of drug‐loaded porous PCL scaffolds . Conventional electrospinning on a rotating mandrel forms a very dense polymer mesh that prevents cell and hydrogel infiltration.…”

“…A drug is also encapsulated in the PCL nanofibers prior to electrospinning for a sustained release. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”

Three‐dimensional electrospun nanofibrous scaffolds for bone tissue engineering

“…Strategies for preparing 3D electrospun nanofibrous scaffolds and the microscopic morphology: (a) sacrificial components (Wang et al, ); (b) wet‐electrospinning (Chakrapani, Kumar, Raj, & Kumary, ; Taskin et al, ); (c) cryogenic electrospinning (Formica et al, ); (d) electrohydrodynamic printing (Wu et al, ); (e) dispersion‐shaping (Xu, Miszuk, Zhao, Sun, & Fong, ); (f) gas‐foaming (Hwang et al, )…”