Aligned Polycaprolactone Nanofibers Research Articles

Functional comparison of beating cardiomyocytes differentiated from umbilical cord-derived mesenchymal/stromal stem cells and human foreskin-derived induced pluripotent stem cells.

In recent years, stem cell-based therapies shown to have promising effects on the clinical management of ischemic heart disease. Moreover, stem cells differentiation into cardiomyocytes (CMs) can overcome the cell source limitations. The current research involves the isolation and expansion of mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs), their differentiation into CMs and subsequent construction of tissue-engineered myocardium supported by random and aligned polycaprolactone (PCL) nanofibrous matrices (av. dia: 350-850 nm). Umbilical cord matrix (UCM)-derived MSCs were isolated successfully by routine enzymatic digestion and a nonenzymatic explant culture method and characterized by their morphology, differentiation into different lineages, and surface marker expression. Treatment of UCM-derived MSCs with 5-azacytidine (5 μM) induced their differentiation into putative cardiac cells, as revealed by the expression of cardiac-specific troponin T (cTnT), smooth muscles actin, myogenin (MYOG), smoothelin, cardiac α-actin genes and cTnT, α-actinin proteins by RT-PCR and immunocytochemistry, respectively. However, no beating cells were observed in differentiated MSCs. On the other hand, adult human foreskin-derived iPSCs cultured on Matrigel™-coated aligned PCL nanofibrous matrices showed anisotropic behavior along the PCL nanofibers and, upon differentiation, expressed cardiac-specific cTnT (23.34 vs. 32.55%) proteins and showed more synchronized beating than those differentiated on Matrigel™-coated tissue culture coated polystyrene surfaces. Moreover, aligned PCL nanofibers are able to promote cells orientation parallel to the fibers, thus providing an effective way to control anisotropic nature under in vitro condition.

A collagen gel-coated, aligned nanofiber membrane for enhanced endothelial barrier function

Herein, a collagen gel-coated and aligned nanofiber membrane named Col-ANM is developed, which remarkably improves endothelial barrier function by providing biochemical and topographical cues simultaneously. Col-ANM is fabricated by collagen gel coating process on an aligned polycaprolactone (PCL) nanofiber membrane, which is obtained by a simple electrospinning process adopting a parallel electrode collector. Human umbilical vein endothelial cells (HUVECs) cultured on Col-ANM exhibit remarkably enhanced endothelial barrier function with high expression levels of intercellular junction proteins of ZO-1 and VE-cadherin, a high TEER, and a cellular permeability compared with the artificial porous membranes in commercial cell culture well inserts. The enhanced endothelial barrier function is conjectured to be attributed to the synergistic effects of topographical and biochemical cues provided by the aligned PCL nanofibers and collagen gel in the Col-ANM, respectively. Finally, the reactive oxygen species is applied to the HUVEC monolayer formed on the Col-ANM to destroy the tight junctions between HUVECs. The destruction of the tight junctions is demonstrated by the decreased TEER value over time. Results indicate the potential of Col-ANM in modeling endothelial barrier dysfunction-related diseases.

Controllable Aligned Nanofiber Hybrid Yarns with Enhanced Bioproperties for Tissue Engineering

AbstractElectrospun nanofibers have large surface area, high porosity, and controllable orientation while conventional microfibers have appropriate mechanical properties such as stiffness, strength, and elasticity. Therefore, the combination of nanofibers and microfibers can provide building elements to engineer biomimetic scaffolds for tissue engineering. In this study, a core–shell structured fibrous structure with controllable surface topography is created by electrospinning polycaprolactone (PCL) nanofibers onto polyglycolic acid (PGA) microfibers. The surface morphology, surface wettability, and mechanical properties of the resultant core–shell structure are characterized. FE‐SEM images reveal that the orientation of PCL nanofibers on the yarn surface can be tuned by a fiber collector and rotating disks. Benefiting from the introduction of a shell of aligned PCL nanofibers on the core of PGA yarn, the uniaxially aligned PCL nanofiber–covered yarns (A‐PCLs) exhibit higher hydrophilicity, porosity, and mechanical properties than the core PGA yarns. Moreover, A‐PCLs promote the adhesion and proliferation of BALB/3T3 (mouse embryonic fibroblast cell line), and guide cell growth along the biotopographic cues of the PCL nanofibers with controllable alignment. The developed core–shell yarn having both the desired surface topography of PCL nanofibers and mechanical properties of PGA microfibers demonstrates great potential in constructing various tissue scaffolds.

Hybrid Additive Microfabrication Scaffold Incorporated with Highly Aligned Nanofibers for Musculoskeletal Tissues.

Latest tissue engineering strategies for musculoskeletal tissues regeneration focus on creating a biomimetic microenvironment closely resembling the natural topology of extracellular matrix. This paper presents a novel musculoskeletal tissue scaffold fabricated by hybrid additive manufacturing method. The skeleton of the scaffold was 3D printed by fused deposition modeling, and a layer of random or aligned polycaprolactone nanofibers were embedded between two frames. A parametric study was performed to investigate the effects of process parameters on nanofiber morphology. A compression test was performed to study the mechanical properties of the scaffold. Human fibroblast cells were cultured in the scaffold for 7days to evaluate the effect of scaffold microstructure on cell growth. The tip-to-collector distance showed a positive correlation with the fiber alignment, and the electrospinning time showed a negative correlation with the fiber density. With reinforced nanofibers, the hybrid scaffold demonstrated superior compression strength compared to conventional 3D-printed scaffold. The hybrid scaffold with aligned nanofibers led to higher cell attachment and proliferation rates, and a directional cell organization. In addition, there was a nonlinear relationship between the fiber diameter/density and the cell actinfilament density. This hybrid biofabrication process can be established as a highly efficient and scalable platform to fabricate biomimetic scaffolds with patterned fibrous microstructure, and will facilitate future development of clinical solutions for musculoskeletal tissue regeneration.

Osteoinductive peptide-functionalized nanofibers with highly ordered structure as biomimetic scaffolds for bone tissue engineering.

The construction of functional biomimetic scaffolds that recapitulate the topographical and biochemical features of bone tissue extracellular matrix is now of topical interest in bone tissue engineering. In this study, a novel surface-functionalized electrospun polycaprolactone (PCL) nanofiber scaffold with highly ordered structure was developed to simulate the critical features of native bone tissue via a single step of catechol chemistry. Specially, under slightly alkaline aqueous solution, polydopamine (pDA) was coated on the surface of aligned PCL nanofibers after electrospinning, followed by covalent immobilization of bone morphogenetic protein-7-derived peptides onto the pDA-coated nanofiber surface. Contact angle measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the presence of pDA and peptides on PCL nanofiber surface. Our results demonstrated that surface modification with osteoinductive peptides could improve cytocompatibility of nanofibers in terms of cell adhesion, spreading, and proliferation. Most importantly, Alizarin Red S staining, quantitative real-time polymerase chain reaction, immunostaining, and Western blot revealed that human mesenchymal stem cells cultured on aligned nanofibers with osteoinductive peptides exhibited enhanced osteogenic differentiation potential than cells on randomly oriented nanofibers. Furthermore, the aligned nanofibers with osteoinductive peptides could direct osteogenic differentiation of human mesenchymal stem cells even in the absence of osteoinducting factors, suggesting superior osteogenic efficacy of biomimetic design that combines the advantages of osteoinductive peptide signal and highly ordered nanofibers on cell fate decision. The presented peptide-decorated bone-mimic nanofiber scaffolds hold a promising potential in the context of bone tissue engineering.

Comparison of random and aligned PCL nanofibrous electrospun scaffolds on cardiomyocyte differentiation of human adipose-derived stem cells.

Cardiomyocytes have small potentials for renovation and proliferation in adult life. The most challenging goal in the field of cardiovascular tissue engineering is the creation of an engineered heart muscle. Tissue engineering with a combination of stem cells and nanofibrous scaffolds has attracted interest with regard to Cardiomyocyte creation applications. Human adipose-derived stem cells (ASCs) are good candidate for use in stem cell-based clinical therapies. They could be cultured and differentiated into several lineages such as cartilage, bone, muscle, neuronal cells, etc. In the present study, human ASCs were cultured on random and aligned polycaprolactone (PCL) nanofibers. The capacity of random and aligned PCL nanofibrous scaffolds to support stem cells for the proliferation was studied by MTT assay. The cardiomyocyte phenotype was first identified by morphological studies and Immunocytochemistry (ICC) staining, and then confirmed with evaluation of specific cardiac related gene markers expression by real-time RT-PCR. The proliferation rate of ASCs on aligned nanofibrous PCL was significantly higher than random nanofibrous PCL. ICC and morphological studies results confirmed cardiomyocyte differentiation of ASCs on the nanofibrous scaffolds. In addition, the expression rate of cardiovascular related gene markers such as GATA-4, α-MHC and Myo-D was significantly increased in aligned nanofibrous PCL compared with random nanofibrous PCL. Our results show that the aligned PCL nanofibers are suitable physical properties as polymeric artificial scaffold in cardiovascular tissue engineering application.

Electrospun fiber membranes enable proliferation of genetically modified cells

Polycaprolactone (PCL) and its blended composites (chitosan, gelatin, and lecithin) are well-established biomaterials that can enrich cell growth and enable tissue engineering. However, their application in the recovery and proliferation of genetically modified cells has not been studied. In the study reported here, we fabricated PCL-biomaterial blended fiber membranes, characterized them using physicochemical techniques, and used them as templates for the growth of genetically modified HCT116-19 colon cancer cells. Our data show that the blended polymers are highly miscible and form homogenous electrospun fiber membranes of uniform texture. The aligned PCL nanofibers support robust cell growth, yielding a 2.5-fold higher proliferation rate than cells plated on standard plastic plate surfaces. PCL-lecithin fiber membranes yielded a 2.7-fold higher rate of proliferation, while PCL-chitosan supported a more modest growth rate (1.5-fold higher). Surprisingly, PCL-gelatin did not enhance cell proliferation when compared to the rate of cell growth on plastic surfaces.