No abstract

PVA‐based hydrogels with tissue engineered scaffolds application commonly need further modification to improve cell‐matrix interactions with respect to subsequent cell proliferation and differentiation. In this study, PVA‐modified hydrogels were formed by subjecting the solutions of PVA/Poly (R‐3‐hydroxybutyrate) (PHB), PVA/Extracellular Matrix (ECM), and PVA/PHB/ECM to freeze–thaw cycles and additive materials effect on cell supporting potential of the hydrogels was investigated. As, limited cell attachment and spreading were observed on PVA blended hydrogels, air plasma surface modification has been performed to promote cell attachment. Attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy revealed the presence of some reactive bonds such as carbonyl on pure and amide on ECM‐coated PVA after plasma exposure. Atomic force microscopy (AFM) also proved increased roughness of hydrogel surface due to the plasma treatment. Plasma modification positive effect on cytoskeleton arrangement of cultured equine adipose derived stem cells (eASCs) was then confirmed by DAPI/phalloidin staining and scanning electron microscopy (SEM) imaging. In summary, among different physical modification approaches, coating with ECM fallowed by air plasma treatment had the most significant effect on cell‐hydrogel interactions. Thus, this combined modification method can be utilized to improve initial attachment and subsequent phenotype of cultured cells on PVA hydrogels for tissue engineering applications.

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In regenerative medicine, extracellular matrix (ECM)‐inspired materials are currently being explored to imitate mechanotransduction pathways and control cell fate. In musculoskeletal tissue regeneration, enhancing mechano‐biological signals require biomaterials that are both biocompatible and viscoelastic and can retain water content. Herein, based on these requirements, various polyvinyl alcohol (PVA)‐based composite hydrogels, reinforced by polyhydroxy butyrate (PHB) nanofibers, are proposed to differentiate equine adipose‐derived stem cells for musculoskeletal regeneration. To study the role of fiber embedding in improving scaffold properties, different nanofiber assemblies, including chopped short ones with random orientation (PVAS), single‐layer (PVAL1), and double‐layer membranes (PVAL2) are positioned into the PVA matrix. PHB reinforcements negatively affect swelling and positively enhanced phase transition temperatures and crystallinity of PVA hydrogel. According to mechanical analysis results, compositing with PHB nanofibrous layers strengthen the PVA matrix due to some restrictions on PVA chain mobility. Gene expression investigations also reveal that higher matrix stiffness after layering with two PHB membranes (PVAL2) promotes osteogenesis, while the random addition of short‐chapped fibers (PVAS) facilitate tenogenic differentiation. As a consequence of the findings, fiber placement is crucial to the mechanical properties of composite hydrogels that ultimately control musculoskeletal differentiation signals through mechanosensing pathways.