Wet-electrospun PHBV nanofiber reinforced carboxymethyl chitosan-silk hydrogel composite scaffolds for articular cartilage repair

Abstract

The objective of the study was to produce three-dimensional and porous nanofiber reinforced hydrogel scaffolds that can mimic the hydrated composite structure of the cartilage extracellular matrix. In this regard, wet-electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber reinforced carboxymethyl chitosan-silk fibroin (PNFs/CMCht-SF) hydrogel composite scaffolds that were chemically cross-linked by poly(ethylene glycol) diglycidyl ether (PEGDE) were produced. To the best of our knowledge, this is the first study in cartilage regeneration where a three dimensional porous spongy composite scaffold was obtained by the dispersion of wet-electrospun nanofibers within a polymer matrix. All of the produced hydrogel composite scaffolds had an interconnected microporous structure with well-integrated PHBV nanofibers on the pore walls. The scaffold comprising an equal amount of PEGDE and polymer (PNFs/CMCht-SF1:PEGDE1) demonstrated comparable water content (91.4 ± 0.7%), tan δ (0.183 at 1 Hz) and compressive strength (457 ± 85 kPa) values to that of articular cartilage. Besides, based on the histological analysis, this hydrogel composite scaffold supported the chondrogenic differentiation of bone marrow mesenchymal stem cells. Consequently, this hydrogel composite scaffold presented a great promise for cartilage tissue regeneration.

Osteochondral Tissue Engineering: The Potential of Electrospinning and Additive Manufacturing

“…The wide diversity of structures that can be generated using electrospinning has been demonstrated by several recent studies [ 286 , 287 , 288 , 289 ]. Liu et al [ 286 ] developed a multi-layered scaffold where an electrospun artificial calcified cartilage layer was included between the AC and SB phases.…”

“…Composite hydrogels fabricated with 65% PEG-PNIPAAm in the polymer blend were biocompatible and promoted a homogeneous cell distribution throughout the constructs, with the production of ECM and expression of type II collagen, aggrecan, and Sox9 coding genes [ 287 ]. Likewise, a poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) nanofibre-reinforced chitosan/silk fibroin hydrogel was produced, where the PHBV fibres were generated by wet electrospinning (fibre collection into a liquid medium) [ 288 ]. The electrospun fibres in suspension were added to chitosan:silk fibroin (1:1 v / v ) solutions, after which crosslinking by poly(ethylene glycol) diglycidyl ether (PEGDE) allowed the gelation and formation of the composite hydrogel.…”

“…Constructs with a chitosan/silk fibroin:PEGDE ratio of 1:1 ( w / w ) demonstrated an interconnected porous structure and a high-water content (~91% of the scaffold’s wet weight), and reinforcement with PHBV electrospun fibres resulted in an improvement of the hydrogel’s mechanical properties. Moreover, the composites successfully promoted proliferation and GAG production by rat BMSCs [ 288 ].…”

“…While PCL provided structural support, the thermosensitivity of PEG-PNIPAAm allowed the loading of the construct with hMSCs at room temperature and subsequent gelation at 37 °C, a characteristic of interest for in vivo and human implantation. Composite hydrogels fabricated with 65% PEG-PNIPAAm in the polymer The wide diversity of structures that can be generated using electrospinning has been demonstrated by several recent studies [286][287][288][289]. Liu et al [286] developed a multi-layered scaffold where an electrospun artificial calcified cartilage layer was included between the AC and SB phases.…”

Electrospinning nanofibers of microbial polyhydroxyalkanoates for applications in medical tissue engineering

“…Meanwhile, the PHBV/hydrogel composite scaffold supported the chondrogenic differentiation of bone marrow mesenchymal stem cells. 182 Therefore, composite scaffolds have become more important with desired biocompatibility, while maintaining high mechanical properties.…”