Valve leaflet‐inspired elastomeric scaffolds with tunable and anisotropic mechanical properties

Abstract

Fibrous scaffolds, which can mimic the elastic and anisotropic mechanical properties of native tissues, hold great promise in recapitulating the native tissue microenvironment. We previously fabricated electrospun fibrous scaffolds made of hybrid synthetic elastomers (poly(1,3‐diamino‐2‐hydroxypropane‐co‐glycerol sebacate)‐co‐poly (ethylene glycol) (APS‐co‐PEG) and polycaprolactone (PCL)) to obtain uniaxial mechanical properties similar to those of human aortic valve leaflets. However, conventional electrospinning process often yields scaffolds with random alignment, which fails to recreate the anisotropic nature of most of the soft tissues such as native heart valves. Inspired by the structure of native valve leaflet, we designed a novel valve leaflet‐inspired ring‐shaped collector to modulate the electrospun fiber alignment and studied the effect of polymer formulation (PEG amount [mole %] in APS‐co‐PEG; ratio between APS‐co‐PEG and PCL; and total polymer concentration) in tuning the biaxial mechanical properties of the fibrous scaffolds. The fibrous scaffolds collected on the ring‐shaped collector displayed anisotropic biaxial mechanical properties, suggesting that their biaxial mechanical properties are closely associated with the fiber alignment in the scaffold. Additionally, the scaffold stiffness was easily tuned by changing the composition and concentration of the polymer blend. Human valvular interstitial cells (hVICs) cultured on these anisotropic scaffolds displayed aligned morphology as instructed by the fiber alignment. Overall, we generated a library of biologically relevant fibrous scaffolds with tunable mechanical properties, which will guide the cellular alignment.

Elastomeric Trilayer Substrates with Native-like Mechanical Properties for Heart Valve Leaflet Tissue Engineering

“…Cell and ECM morphology and orientation are impacted by the orientation of the fibers in electrospun substrates . Also, substrates with native-like anisotropy and mechanical properties could enhance cell proliferation and ECM production. , Thus, the PCL and PCL/PLCL cell-cultured constructs were stained with H&E, Masson’s trichrome, or Alcian blue to confirm the presence and orientation of cells, collagen fibrils, and GAG, respectively. Further, staining of the constructs was used to verify the formation of circumferential, random, and radial orientations in three layers mimicking the native leaflet tissue structure.…”

Poly(Glycerol Sebacate) in Biomedical Applications—A Review of the Recent Literature

“…Modified PGS, i.e., poly(1,3‐diamino‐2‐hydroxypropane‐ co ‐glycerol sebacate)‐ co ‐PEG, has also been electrospun together with PCL in order to obtain fiber mats exhibiting uniaxial mechanical properties required for human aortic valve leaflets. [ 171 ]…”

“…Modified PGS, i.e., poly(1,3-diamino-2-hydroxypropane-co-glycerol sebacate)-co-PEG, has also been electrospun together with PCL in order to obtain fiber mats exhibiting uniaxial mechanical properties required for human aortic valve leaflets. [171] Furthermore, PGS/PCL electrospun fibers have been used as reinforcement for methacrylated gelatin/hyaluronic acid hydrogels via immersion technique. [146] PGS/PCL fiber/hydrogel composite scaffolds showed higher metabolic activity of valvular interstitial cells compared to the fiber mat and the hydrogel alone.…”

A Comprehensive Review on Bio-Nanomaterials for Medical Implants and Feasibility Studies on Fabrication of Such Implants by Additive Manufacturing Technique

“…For example, Puperi et al used the combination of electrospun polyurethane with a PEG-based hydrogel to recreate the heterogeneous structure of a heart-valve tissue [74]. Xue et al studied the impact of the polymer formulation on the fiber morphology and the biaxial mechanical properties of elastomeric fibrous scaffolds made of PEG-based hydrogels and PCL blends [75]. Ravichandran et al analyzed the potential of a core-shell nanofibrous cardiac patch as a regenerative technique after myocardial infarction [76].…”