Nanofiber scaffold gradients for interfacial tissue engineering

Abstract

We have designed a 2-spinnerette device that can directly electrospin nanofiber scaffolds containing a gradient in composition that can be used to engineer interfacial tissues such as ligament and tendon. Two types of nanofibers are simultaneously electrospun in an overlapping pattern to create a nonwoven mat of nanofibers containing a composition gradient. The approach is an advance over previous methods due to its versatility - gradients can be formed from any materials that can be electrospun. A dye was used to characterize the 2-spinnerette approach and applicability to tissue engineering was demonstrated by fabricating nanofibers with gradients in amorphous calcium phosphate nanoparticles (nACP). Adhesion and proliferation of osteogenic cells (MC3T3-E1 murine pre-osteoblasts) on gradients was enhanced on the regions of the gradients that contained higher nACP content yielding a graded osteoblast response. Since increases in soluble calcium and phosphate ions stimulate osteoblast function, we measured their release and observed significant release from nanofibers containing nACP. The nanofiber-nACP gradients fabricated herein can be applied to generate tissues with osteoblast gradients such as ligaments or tendons. In conclusion, these results introduce a versatile approach for fabricating nanofiber gradients that can have application for engineering graded tissues.

Nanoengineered biomaterials for repair and regeneration of orthopedic tissue interfaces

“…[113] A two-spinneret system was developed to fabricate a nanofiber scaffold gradient in another study. [114][115][116] The nanofibers were fabricated from PCL modified with amorphous calcium phosphate nanoparticles (nACP). PCL scaffolds have shown to support osteogenesis and addition of calcium phosphate can further promote deposition of mineralized ECM.…”

“…This trend is similar to the noncalcified to calcified transition in the native ligament-bone interfaces. [116] This study, however, did not consider any structural aspects of native tissue and additional experiments to investigate the effect of mechanical loading on ECM production need to be investigated.…”

“…[113] PCL nanofibers with nACP PCL nanofibers Two-spinneret approach for direct nanofiber gradient without additional modification. [116] Scaffold ECM production and mechanical loading were not evaluated. [116] PLGA randomly oriented nanofibers PCL aligned nanofibers Electrospun 2D meshes and 3D cylindrical composites with controlled fiber orientation, diameter, chemistry, and mechanical properties.…”

Airbrushed Composite Polymer Zr-ACP Nanofiber Scaffolds with Improved Cell Penetration for Bone Tissue Regeneration

“…26 In vitro studies indicate that ACP composites can support mouse osteoblastic cell growth and differentiation. [27][28][29] In addition, recent studies have shown that poly(lactic-co-glycolic acid) microspheres coated with zirconium-modified amorphous calcium phosphate (Zr-ACP) promoted preosteoblast cell attachment and supported cell differentiation. 28,30 Although electrospinning provides fine control over nanofiber synthesis, there are some limitations to applications in tissue engineering such as the inability to deposit fibers without an electric field, slow deposition rates, complex synthesis setups, and poor cell penetration within a fibrous network.…”

Fabrication of Magnetite/Pla Composite Nanofiber Sheet and Evaluation of Its Mechanical Properties

“…Due to special characteristics of nanofibers such as nanometer sized diameter, high surface area to volume ratio and higher alignment of molecular chains [1], [2], nanofibers are expected to be widely used in many applications such as filter medias [3], drug delivery systems [4] and scaffolds [5]. Nanofibers containing magnetic nanoparticles have potential uses as functional nanofibers for many applications such as sensors and materials for drug delivery systems.…”