Enhanced chondrogenic differentiation of bone marrow mesenchymal stem cells on gelatin/glycosaminoglycan electrospun nanofibers with different amount of glycosaminoglycan

Tissue engineering is a new technique to help damaged cartilage treatment using cells and scaffolds. In this study we tried to evaluate electrospun scaffolds composed of gelatin/glycosaminoglycan (G/GAG) blend nanofibers in chondrogenesis of bone marrow-derived mesenchymal stem cells (BMMSCs). Scaffolds were fabricated by electrospinning technique with different concentration of glycosaminoglycan (0, 5, 10, and 15) in gelatin matrix. BMMSCs were cultured on the scaffolds for chondrogenesis process. MTT assay was done for scaffold's biocompatibility and cells viability evaluation. Alcian blue staining was carried out to determine the release of GAG and reverse transcription polymerase chain reaction (RT-PCR) was done for expression of COL2A1 and also immunocytochemistry assay were used to confirm expression of type II collagen. Scaffold with 15 GAG showed better result for biocompatibility (p =0.02). Scanning electron microscopy (SEM) micrographs showed that MSCs have good attachment to the scaffolds. Alcian blue staining result confirmed that cells produce GAG during differentiation time different from GAG in the scaffolds. Also the results for RT-PCR showed the expression of COL2A1 marker. Immunocytochemistry assay for type II collagen confirm that this protein expressed. Scaffold comprising 15 GAG is better results for chondrogenesis and it can be a good applicant for cartilage tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 38�48, 2019. © 2018 Wiley Periodicals, Inc

Cardiac ECM/chitosan/alginate ternary scaffolds for cardiac tissue engineering application

Since cardiovascular diseases are the number one cause of death in worldwide, and the traditional treatments have limitations, the emergence of cardiac tissue engineering (CTE) can be a promising approach. In this study, scaffold fabrication from the solubilized cardiac extracellular matrix (ECM) accompanied with alginate and chitosan for CTE was carried out. The influence of blending ratios on chemical and physical properties of the scaffolds including FTIR spectroscopy, porosity, pore size, and their mechanical properties were investigated. The porosity of scaffolds was more than 96 with very high swelling rate while maintaining their stability in PBS solution. Blending ECM with chitosan and alginate significantly improve the tensile strength of ECM. FTIR spectrum of scaffolds demonstrated interaction of solubilized ECM with two opposite-charged polysaccharides. The proliferation of human mesenchymal stem cells (hMSCs) on the ternary scaffolds using MTS assay, revealed that blending ECM with polysaccharides at ratio of 75: 25 (E75/P25) led to improve the proliferation of hMSCs on scaffolds. Scanning electron microscope (SEM) revealed the porous structure and the presence of hMSCs cells inside the pores. In addition, histological analysis confirmed that cardiomyocyte penetration inside scaffolds after 7 days of culture. The immunofluorescence staining revealed that higher expression of cardiac marker (cTnT) in ternary scaffold in comparison with ECM. © 202

Polyvinyl alcohol/sulfated alginate nanofibers induced the neuronal differentiation of human bone marrow stem cells

Scaffolds that are used for neural tissue engineering are fabricated to mimic the extracellular matrix. In this paper, we have fabricated polyvinyl alcohol/sulfated alginate (PVA/SA) nanofibers with different concentrations (10, 20 and 30 wt) of sulfated alginate by electrospinning technique. The average fibers diameters of 169�488 nm were achieved by electrospinning of polymers blend (PVA/SA). The results of the MTT assay and scanning electron microscopy showed that PVA/sulfated alginate nanofibrous scaffold with 30 wt SA provided more desirable surface attachment of C6, Schwann cells (SCs) and human bone marrow mesenchymal stem cells (hBMSCs). RT-PCR and immunocytochemistry for MAP-2 marker were conducted to confirm the neural-differentiation of hBMSCs. The expression of MAP-2 confirmed neural differentiation for up to 14 days. Our results showed that PVA/SA nanofibrous scaffold with 30 wt SA is a suitable substrate for mesenchymal stem cells growth and is capable of inducing neuronal differentiation. © 2019 Elsevier B.V

Alginate-magnetic short nanofibers 3D composite hydrogel enhances the encapsulated human olfactory mucosa stem cells bioactivity for potential nerve regeneration application

The design of 3D hydrogel constructs to elicit highly controlled cell response is a major field of interest in developing tissue engineering. The bioactivity of encapsulated cells inside pure alginate hydrogel is limited by its relatively inertness. Combining short nanofibers within a hydrogel serves as a promising method to develop a cell friendly environment mimicking the extracellular matrix. In this paper, we fabricated alginate hydrogels incorporating different magnetic short nanofibers (M.SNFs) content for olfactory ecto-mesenchymal stem cells (OE-MSCs) encapsulation. Wet-electrospun gelatin and superparamagnetic iron oxide nanoparticles (SPIONs) nanocomposite nanofibers were chopped using sonication under optimized conditions and subsequently embedded in alginate hydrogels. The storage modulus of hydrogel without M.SNFs as well as with 1 and 5 mg/mL of M.SNFs were in the range of nerve tissue. For cell encapsulation, OE-MSCs were used as a new hope for neuronal regeneration due to their neural crest origin. Resazurin analyses and LIVE/DEAD staining confirmed that the composite hydrogels containing M.SNFs can preserve the cell viability after 7 days. Moreover, the proliferation rate was enhanced in M.SNF/hydrogels compared to alginate hydrogel. The presence of SPIONs in the short nanofibers can accelerate neural-like differentiation of OE-MSCs rather than the sample without SPIONs. © 2020 Elsevier B.V

Chondroitin sulfate immobilized PCL nanofibers enhance chondrogenic differentiation of mesenchymal stem cells

Cold Atmospheric Plasma (CAP) is used as a promising method in surface modification for immobilization of chondroitin sulfate functional biomacromolecules on PCL nanofibrous substrates for cartilage tissue engineering. The GAG-grafted scaffolds are able to successfully support the attachment and proliferation of mesenchymal stem cells (MSCs). The seeded scaffolds show the chondro-differentiation of MSCs during a 21-days cell culture in a non-differential medium. Expression of SOX9, Collagen10 and Collagen2 proved the chondro-inductive effect of GAG-grafted scaffolds. Besides, no external chondro-genic differential agent was used in the differentiation of MSCs to chondrocyte. The cells passed the last phase of chondrogenesis after 14 days of incubation. Thus, the GAG-fabricated fibrous scaffolds using CAP are potential candidates for cartilage tissue engineering. © 201

An injectable anisotropic alginate hydrogel containing oriented fibers for nerve tissue engineering

There is a growing research interest on designing a tissue regenerative matrix that can be injected and forms an anisotropic network for effective nerve injury repair. Here, an injectable alginate hydrogel composed of magnetic polycaprolactone (PCL) short nanofibers were fabricated. Nanocomposite PCL centrifugal spun fibers containing superparamagnetic iron oxide nanoparticles (SPIONs) were cut into short nanofibers (SFs) through micro-cutting technique and subsequently incorporated into alginate hydrogels. Doping SPION into short PCL fibers allows the SFs alignment by external magnetic fields in the millitesla (mT) order within the hydrogel. The effect of SFs lengths (5, 25 and 50 µm) as well as magnetic short fibers (M.SFs) concentration (0.5, 1, 2.5, 5 and 10 mg / ml) inside alginate hydrogel on fiber orientation under external magnetic field were investigated by measuring angular deflection of nanofibers. The results revealed that 5 and 25 µm M.SFs with 5 mg/ml concentration have the lowest angular deflection of 1.1� and 6.8�, respectively. The mechanical properties of prepared hydrogels revealed that both oriented 5 and 25 µm M.SFs, have higher storage modulus (G�) and loss modulus (G�) values than the random ones and by increasing M.SFs length from 5 µm to 25 µm, G� and G� values displayed descending trend. The fluorescence microscopy of olfactory ecto-mesenchymal stem cells (OE-MSCs) encapsulated in hybrid hydrogels containing oriented M.SFs showed the possibility of preserving cell viability after 7 days. Following 14-day of induction, the oriented 25 µm M.SF led to the acceleration of neural differentiation of OE-MSCs versus the random one. Therefore, it was expected that ordered injectable alginate/M.SFs hybrid hydrogels function as a minimal invasive constructs for the regeneration of neural tissues. © 2021 Elsevier B.V

Co-electrospun gelatin-chondroitin sulfate/polycaprolactone nanofibrous scaffolds for cartilage tissue engineering

Chondroitin sulfate and gelatin (GEL-CS) as a component of cartilage extracellular matrix were incorporated by polycaprolactone (PCL)nanofibers utilizing co-electrospinning process to fabricate composite scaffolds for inducing chondrogenesis of human bone mesenchymal stem cells (hMSCs) differentiation without using differential medium. The MTT anSSEM results illustrated supported cellular attachment and viability of hMSCs on scaffolds. Sulfated glycosaminoglycan secretion staining, genes expression of COL2a1 and SOX9 and also type ⠡ collagen protein approved the differentiation of seeded hMSCs to chondrocytes without using any external chondrogenic differential factor. The scaffolds containing the highest GEL-CS content (2/1) exhibit better chondrogenesis differentiation results and it can be introduced as acceptable potential for cartilage tissue engineering application. © 2020 Elsevier Lt

Alginate sulfate/ECM composite hydrogel containing electrospun nanofiber with encapsulated human adipose-derived stem cells for cartilage tissue engineering

Stem cell therapy is a promising strategy for cartilage tissue engineering, and cell transplantation using polymeric scaffolds has recently gained attention. Herein, we encapsulated human adipose-derived stem cells (hASCs) within the alginate sulfate hydrogel and then added them to polycaprolactone/gelatin electrospun nanofibers and extracellular matrix (ECM) powders to mimic the cartilage structure and characteristic. The composite hydrogel scaffolds were developed to evaluate the relevant factors and conditions in mechanical properties, cell proliferation, and differentiation to enhance cartilage regeneration. For this purpose, different concentrations (1–5 % w/v) of ECM powder were initially loaded within an alginate sulfate solution to optimize the best composition for encapsulated hASCs viability. Adding 4 % w/v of ECM resulted in optimal mechanical and rheological properties and better cell viability. In the next step, electrospun nanofibrous layers were added to the alginate sulfate/ECM composite to prepare different layered hydrogel-nanofiber (2, 3, and 5-layer) structures with the ability to mimic the cartilage structure and function. The 3-layer structure was selected as the optimum layered composite scaffold, considering cell viability, mechanical properties, swelling, and biodegradation behavior; moreover, the chondrogenesis potential was assessed, and the results showed promising features for cartilage tissue engineering application

Alginate sulfate-based hydrogel/nanofiber composite scaffold with controlled Kartogenin delivery for tissue engineering

In this study, we fabricated two different arrangements of laminated composite scaffolds based on Alginate:Alginate sulfate hydrogel, PCL:Gelatin electrospun mat, and Kartogenin-PLGA nanoparticles (KGN-NPs). The optimized composite scaffold revealed a range of advantages such as improved mechanical features as well as less potential of damage (less dissipated energy), interconnected pores of hydrogel and fiber with adequate pore size, excellent swelling ratio, and controlled biodegradability. Furthermore, the synthesized KGN-NPs with spherical morphology were incorporated into the composite scaffold and exhibited a linear and sustained release of KGN within 30 days with desirable initial burst reduction (12 vs. 20). Additionally, the cytotoxicity impact of the composite was evaluated. Resazurin assay and Live/Dead staining revealed that the optimized composite scaffold has no cytotoxic effect and could improve cell growth. Overall, according to the enhanced mechanical features, suitable environment for cellular growth, and sustained drug release, the optimized scaffold would be a good candidate for tissue regeneration. © 2021 Elsevier Lt