Conductive gradient hydrogels allow spatial control of adult stem cell fate.

Electrical gradients are fundamental to physiological processes including cell migration, tissue formation, organ development, and response to injury and regeneration. Current electrical modulation of cells is primarily studied under a uniform electrical field. Here we demonstrate the fabrication of conductive gradient hydrogels (CGGs) that display mechanical properties and varying local electrical gradients mimicking physiological conditions. The electrically-stimulated CGGs enhanced human mesenchymal stem cell (hMSC) viability and attachment. Cells on CGGs under electrical stimulation showed a high expression of neural progenitor markers such as Nestin, GFAP, and Sox2. More importantly, CGGs showed cell differentiation toward oligodendrocyte lineage (Oligo2) in the center of the scaffold where the electric field was uniform with a greater intensity, while cells preferred neuronal lineage (NeuN) on the edge of the scaffold on a varying electric field at lower magnitude. Our data suggest that CGGs can serve as a useful platform to study the effects of electrical gradients on stem cells and potentially provide insights on developing new neural engineering applications.

Wirelessly Powered-Electrically Conductive Polymer System for Stem Cell Enhanced Stroke Recovery.

Effective stroke recovery therapeutics remain limited. Stem cell therapies have yielded promising results, but the harsh ischemic environment of the post-stroke brain reduces their therapeutic potential. Previously, we developed a conductive polymer scaffold system that enabled stem cell delivery with simultaneous electrical modulation of the cells and surrounding neural environment. This wired polymer scaffold proved efficacious in optimizing ideal conditions for stem cell mediated motor improvements in a rodent model of stroke. To further enable preclinical studies and enhance translational potential, we identified a method to improve this system by eliminating its dependence upon a tethered power source. We have herein developed a wirelessly powered, electrically conductive polymer system that eases therapeutic application and enables full mobility. As a proof of concept, we demonstrate that the wirelessly powered scaffold is able to stimulate neural stem cells in vitro, as well as in vivo in a rodent model of stroke. This system modulates the stroke microenvironment and increases the production of endogenous stem cells. In summation, this novel, wirelessly powered conductive scaffold can serve as a mobile platform for a wide variety of therapeutics involving electrical stimulation.

Electrical modulation of transplanted stem cells improves functional recovery in a rodent model of stroke.

Stroke is a leading cause of long-term disability worldwide, intensifying the need for effective recovery therapies. Stem cells are a promising stroke therapeutic, but creating ideal conditions for treatment is essential. Here we developed a conductive polymer system for stem cell delivery and electrical modulation in animals. Using this system, electrical modulation of human stem cell transplants improve functional stroke recovery in rodents. Increased endogenous stem cell production corresponds with improved function. Transcriptome analysis identified stanniocalcin 2 (STC2) as one of the genes most significantly upregulated by electrical stimulation. Lentiviral upregulation and downregulation of STC2 in the transplanted stem cells demonstrate that this glycoprotein is an essential mediator in the functional improvements seen with electrical modulation. Moreover, intraventricular administration of recombinant STC2 post-stroke confers functional benefits. In summation, our conductive polymer system enables electrical modulation of stem cells as a potential method to improve recovery and identify important therapeutic targets.

Modulating the Electrical and Mechanical Microenvironment to Guide Neuronal Stem Cell Differentiation.

The application of induced pluripotent stem cells (iPSCs) in disease modeling and regenerative medicine can be limited by the prolonged times required for functional human neuronal differentiation and traditional 2D culture techniques. Here, a conductive graphene scaffold (CGS) to modulate mechanical and electrical signals to promote human iPSC-derived neurons is presented. The soft CGS with cortex-like stiffness (≈3 kPa) and electrical stimulation (±800 mV/100 Hz for 1 h) incurs a fivefold improvement in the rate (14d) of generating iPSC-derived neurons over some traditional protocols, with an increase in mature cellular markers and electrophysiological characteristics. Consistent with other culture conditions, it is found that the pro-neurogenic effects of mechanical and electrical stimuli rely on RhoA/ROCK signaling and de novo ciliary neurotrophic factor (CNTF) production respectively. Thus, the CGS system creates a combined physical and continuously modifiable, electrical niche to efficiently and quickly generate iPSC-derived neurons.

FDA Approval Summary: Selumetinib for Plexiform Neurofibroma.

On April 10, 2020, the FDA approved selumetinib (KOSELUGO, AstraZeneca) for the treatment of pediatric patients 2 years of age and older with neurofibromatosis type 1 who have symptomatic, inoperable plexiform neurofibromas. Approval was based on demonstration of a durable overall response rate per Response Evaluation in Neurofibromatosis and Schwannomatosis criteria and supported by observed clinical improvements in plexiform neurofibroma-related symptoms and functional impairments in 50 pediatric patients with inoperable plexiform neurofibromas in a single-arm, multicenter trial. The overall reponse rate per NCI investigator assessment was 66% (95% confidence interval, 51-79) with at least 12 months of follow-up. The median duration of response was not reached, and 82% of responding patients experienced duration of response ≥12 months. Clinical outcome assessment endpoints provided supportive efficacy data. Risks of selumetinib are consistent with MAPK (MEK) inhibitor class effects, including ocular, cardiac, musculoskeletal, gastrointestinal, and dermatologic toxicities. Safety was assessed across a pooled database of 74 pediatric patients with plexiform neurofibromas and supported by adult and pediatric selumetinib clinical trial data in cancer indications. The benefit-risk assessment for selumetinib in patients with inoperable plexiform neurofibromas was considered favorable.

Single-Cell Encapsulation via Click-Chemistry Alters Production of Paracrine Factors from Neural Progenitor Cells.

Extracellular matrix (ECM) properties affect multiple cellular processes such as cell survival, proliferation, and protein synthesis. Thus, a polymeric-cell delivery system with the ability to manipulate the extracellular environment can act as a fundamental regulator of cell function. Given the promise of stem cell therapeutics, a method to uniformly enhance stem cell function, in particular trophic factor release, can prove transformative in improving efficacy and increasing feasibility by reducing the total number of cells required. Herein, a click-chemistry powered 3D, single-cell encapsulation method aimed at synthesizing a polymeric coating with the optimal thickness around neural progenitor cells is introduced. Polymer encapsulation of neural stem cells significantly increases the release of neurotrophic factors such as VEGF and CNTF. Cell encapsulation with a soft extracellular polymer upregulates the ADCY8-cAMP pathway, suggesting a mechanism for the increase in paracrine factors. Hence, the described single-cell encapsulation technique can emerge as a translatable, nonviral cell modulation method and has the potential to improve stem cells' therapeutic effect.

Controlling properties of human neural progenitor cells using 2D and 3D conductive polymer scaffolds.

Human induced pluripotent stem cell-derived neural progenitor cells (hNPCs) are a promising cell source for stem cell transplantation to treat neurological diseases such as stroke and peripheral nerve injuries. However, there have been limited studies investigating how the dimensionality of the physical and electrical microenvironment affects hNPC function. In this study, we report the fabrication of two- and three-dimensional (2D and 3D respectively) constructs composed of a conductive polymer to compare the effect of electrical stimulation of hydrogel-immobilized hNPCs. The physical dimension (2D vs 3D) of stimulating platforms alone changed the hNPCs gene expression related to cell proliferation and metabolic pathways. The addition of electrical stimulation was critical in upregulating gene expression of neurotrophic factors that are important in regulating cell survival, synaptic remodeling, and nerve regeneration. This study demonstrates that the applied electrical field controls hNPC properties depending on the physical nature of stimulating platforms and cellular metabolic states. The ability to control hNPC functions can be beneficial in understanding mechanistic changes related to electrical modulation and devising novel treatment methods for neurological diseases.

Conductive polymers to modulate the post-stroke neural environment.

Despite the prevalence of stroke, therapies to augment recovery remain limited. Here we focus on the use of conductive polymers for cell delivery, drug release, and electrical stimulation to optimize the post-stroke environment for neural recovery. Conductive polymers and their interactions with in vitro and in vivo neural systems are explored. The ability to continuously modify the neural environment utilizing conductive polymers provides applications in directing stem cell differentiation and increasing neural repair. This exciting class of polymers offers new approaches to optimizing the post-stroke brain to improve functional recovery.

Engineered stem cell mimics to enhance stroke recovery.

Currently, no medical therapies exist to augment stroke recovery. Stem cells are an intriguing treatment option being evaluated, but cell-based therapies have several challenges including developing a stable cell product with long term reproducibility. Since much of the improvement observed from cellular therapeutics is believed to result from trophic factors the stem cells release over time, biomaterials are well-positioned to deliver these important molecules in a similar fashion. Here we show that essential trophic factors secreted from stem cells can be effectively released from a multi-component hydrogel system into the post-stroke environment. Using our polymeric system to deliver VEGF-A and MMP-9, we improved recovery after stroke to an equivalent degree as observed with traditional stem cell treatment in a rodent model. While VEGF-A and MMP-9 have many unique mechanisms of action, connective tissue growth factor (CTGF) interacts with both VEGF-A and MMP-9. With our hydrogel system as well as with stem cell delivery, the CTGF pathway is shown to be downregulated with improved stroke recovery.

Electrically Conductive Scaffold to Modulate and Deliver Stem Cells.

Stem cell therapy has emerged as an exciting stroke therapeutic, but the optimal delivery method remains unclear. While the technique of microinjection has been used for decades to deliver stem cells in stroke models, this technique is limited by the lack of ability to manipulate the stem cells prior to injection. This paper details a method of using an electrically conductive polymer scaffold for stem cell delivery. Electrical stimulation of stem cells using a conductive polymer scaffold alters the stem cell's genes involved in cell survival, inflammatory response, and synaptic remodeling. After electrical preconditioning, the stem cells on the scaffold are transplanted intracranially in a distal middle cerebral artery occlusion rat model. This protocol describes a powerful technique to manipulate stem cells via a conductive polymer scaffold and creates a new tool to further develop stem cell-based therapy.

Electrical preconditioning of stem cells with a conductive polymer scaffold enhances stroke recovery.

Exogenous human neural progenitor cells (hNPCs) are promising stroke therapeutics, but optimal delivery conditions and exact recovery mechanisms remain elusive. To further elucidate repair processes and improve stroke outcomes, we developed an electrically conductive, polymer scaffold for hNPC delivery. Electrical stimulation of hNPCs alters their transcriptome including changes to the VEGF-A pathway and genes involved in cell survival, inflammatory response, and synaptic remodeling. In our experiments, exogenous hNPCs were electrically stimulated (electrically preconditioned) via the scaffold 1 day prior to implantation. After in vitro stimulation, hNPCs on the scaffold are transplanted intracranially in a distal middle cerebral artery occlusion rat model. Electrically preconditioned hNPCs improved functional outcomes compared to unstimulated hNPCs or hNPCs where VEGF-A was blocked during in vitro electrical preconditioning. The ability to manipulate hNPCs via a conductive scaffold creates a new approach to optimize stem cell-based therapy and determine which factors (such as VEGF-A) are essential for stroke recovery.

Computational Analysis on Down-Regulated Images of Macrophage Scavenger Receptor.

BACKGROUND: Thiolated-graphene quantum dots (SH-GQDs) were developed and assessed for an efficient preventive means against atherosclerosis and potential toxicity through computational image analysis and animal model studies. EXPERIMENTS: Zebrafish (wild-type, wt) were used for evaluation of toxicity through the assessment of embryonic mortality, malformation and ROS generation. The amounts of SH-GQDs uptaken by mouse macrophage cells (Raw264.7) were analyzed using a flow cytometer. For the time-dependent cellular uptake study, Raw264.7 cells were treated with SH-GQDs (200 µg/ml) at specific time intervals (0.5, 1, 2, 5, 10 and 24 h). The efficacy of SH-GQDs on DiO-oxLDL efflux by Raw264.7 cells was evaluated (DiO, 3,3'-dioctadecyl-oxacarbocyanine) based on the percentage of positive cells containing DiO-oxLDL. TEER of human primary umbilical vein endothelial cells (hUVECs) were examined to assess the barrier function of the cell layers upon being treated with oxLDL. RESULTS: SH-GQDs significantly enhanced the efflux of oxLDL and down-regulated macrophage scavenger receptor (MSR) in Raw264.7. The ROS levels stimulated by oxidative stress were alleviated by SH-GQDs. oxLDL (10 µg/ml) significantly impaired the barrier function (TEER) of adherence junctions, which was recovered by SH-GQDs (10 µg/ml) (oxLDL: 67.2 ± 2.2 Ω-cm2 for 24 h; SH-GQDs: 114.6 ± 8.5 Ω-cm2 for 24 h). The mortality rate (46% for 1 mg/ml) of the zebra fish increased, as the concentrations and exposure duration of SH-GQDs increased. SH-GQDs exerted negligible side effects. CONCLUSION: SH-GQDs have target specificity to macrophage scavenger receptor (MSR) and efficiently recovered the ROS levels and TEER. SH-GQDs did not induce endothelial cell layer disruption nor affected zebrafish larvae survival.

Development of Thiolated-Graphene Quantum Dots for Regulation of ROS in macrophages.

PURPOSE: The current study was designed to develop thiolated-graphene quantum dots (SH-GQDs) as a theranostic nanocarrier and evaluate its potential for the optimal scavenging of reactive oxygen species (ROS) in macrophages. METHODS: SH-GQDs were prepared by hydrothermal pyrolysis of carbon source (citric acid) in the presence of reduced-glutathione (GSH). Raw264.7 cells were treated with varying concentrations of oxLDL (0.5, 1 and 2 µg/ml) in the presence or absence of SH-GQDs and cells were stained with peroxide-sensitive fluorescent dye (DCFDA). Flow cytometry analysis was performed to investigate the expression of MSR and ATP-binding cassette transporter (ABCA1) after such treatments as the negative control, oxLDL treatment and oxLDL treatment in the presence of either GQDs or SH-GQDs. RESULTS: SH-GQDs had a size ranging from 10 to 30 nm with an average size of 21.3 ± 5.2 nm. The elemental analysis indicated that SH-GQDs are mainly composed of carbon, nitrogen, oxygen and sulfur. The expression levels of ABCA1 in macrophages treated with either LDL or oxLDL were lower than those treated with the media control (the negative control: 100 ± 7.6%; LDL: 82.7 ± 1.2%; and oxLDL: 79.2 ± 1.7%). The level of ABCA1 expression increased as cells were incubated with SH-GQDs (SH-GQDs: 101.5 ± 3.1%). The level of MSR on the surface of macrophages upon being treated with SH-GQDs was lower than those with oxLDL (oxLDL: 112.1 ± 8.8% and SH-GQDs: 91.5 ± 4.2%). CONCLUSION: The enhancement of lipid efflux and down-regulation of MSR in macrophages by SH-GQDs supported its promising usage as a theranostic nanocarrier to prevent foam cell formation and plaque development.

Development of Man-rGO for Targeted Eradication of Macrophage Ablation.

This study was aimed to develop and evaluate a smart nanosystem that targeted photothermal ablation of inflammatory macrophages in atherosclerotic plaque. Mannosylated-reduced graphene oxide (Man-rGO) was synthesized using three step procedures: (1) preparation of ox-GOs, (2) microwave-assisted synthesis of PEI-rGOs, and (3) mannosylation of PEI-rGO using reductive amination reaction (Man-rGOs). The ζ-potential of Man-rGO that signifies electrophoretic mobility of the charged surface was examined using Zetasizer Nano ZS. The effects of Man-rGO on the cell viability was evaluated using LDH assay and AlamarBlue assay. The targeting efficacy of Man-rGO was assessed using the cellular uptake rate by M2-polarized (i.e., which is induced by IL-4) macrophage. The effects of NOMela loaded in Man-rGO on the enhancement of phagocytosis were evaluated by examining the phagocytic clearance rate of zymosan-FITC particles. The microwave-assisted reduction of GOs was adapted for a facile synthesis of polyethylenimine-reduced GO (PEI-rGO). The mannose functionalization (Man-rGO) of PEI-rGO produced a greater number of amide linkages formed by reductive amination reaction between PEI-rGO and mannose. The ζ-potential of PEI-rGO was +30.6 ± 3.3 mV, whereas that of Man-rGO was down to +13.1 ± 3.8 mV upon interaction with mannose mainly due to the conjugation of mannose on the PEI-rGO surface. Near-infrared (NIR) irradiation increased the temperature of Man-rGO solution to around 45 °C, suggesting that Man-rGO is more potent than ox-GO or rGO in photothermal ablation activity triggered by NIR laser irradiation (808 nm). All testing formulations at the concentrations up to 10 µg/mL exerted less than 10% of membrane disintegration. For AlamarBlue study, more than 90% of cell viability were maintained at the concentrations (up to 10 µg/mL) of all tested formulations. The fluorescent microscopy images of cells after 1 h incubation demonstrated that Man-rGO were mainly accumulated at the subcellular level where the mannose receptors were overexpressed. The cell viability of macrophages significantly decreased upon exposure to Man-rGO irradiated with NIR, but no changes were observed from that of mast cells (for mast cells, 98.3 ± 0.3%; for macrophages, 67.8 ± 1.3%, p < 0.01), indicating that Man-rGO achieved enhanced targetability toward mannose receptor mediated cellular uptake. N-Nitrosomelatonin (NOMela) loaded in macrophage exerted enhanced phagocytic activity. It was concluded that the enhanced photothermal ablation activity of Man-rGO triggered by NIR laser irradiation was mediated through their targetability toward overexpressed mannose receptor, a marker of M2-phenotype of macrophage. The results of this study supported that Man-rGO can serve as an efficient platform for the targeted therapy against atherosclerosis.

Biomimicking Robust Hydrogel for the Mesenchymal Stem Cell Carrier.

PURPOSE: This study was aimed to develop a hydrogel-nanofiber as an advanced carrier for adipose derived human mesenchymal stem cells (AD-MSCs) and evaluate its potential for immunomodulatory therapies applicable to surface coating of drug eluting stent (DES) against coronary artery diseases (CAD). METHODS: A mixture of dispersing-nanofibers (dNFs) and poly (ethylene glycol)-diacrylate (PEGDA) were blended with sodium alginate to achieve robust mechanical strength. The effects of stem cell niche on cell viability and proliferation rates were evaluated using LDH assay and alamar blue assay, respectively. The amount of Nile-red microparticles (NR-MPs) remained in the hydrogel scaffolds was examined as an index for the physical strength of hydrogels. To evaluate the immunomodulatory activity of AD-MSCs as well as their influence by ROS, the level of L-Kynurenine was determined as tryptophan replacement compounds in parallel with IDO secreted from AD-MSCs using a colorimetric assay of L-amino acid. RESULTS: Both SA-cys-PEG and SA-cys-dNF-PEG upon being coated on stents using electrophoretic deposition technique displayed superior mechanical properties against the perfused flow. d-NFs had a significant impact on the stability of SA-cys-dNF-PEG, as evidenced by the substantial amount of NR-MPs remained in them. An enhanced subcellular level of ROS by spheroidal cluster yielded the high concentrations of L-Kynurenine (1.67 ± 0.6 µM without H2O2, 5.2 ± 1.14 µM with 50 µM of H2O2 and 8.8 ± 0.51 µM with 100 µM of H2O2), supporting the IDO-mediated tryptophan replacement process. CONCLUSION: The "mud-and-straw" hydrogels are robust in mechanical property and can serve as an ideal niche for AD-MSCs with immunomodulatory effects.

Nanofiber-coated drug eluting stent for the stabilization of mast cells.

PURPOSE: The nanofiber-hydrogel blend containing nitric oxide (NO) donors and reactive oxygen species (ROS) scavengers (Edaravone: EDV) was explored as an advanced strategy for stabilization of Mast cells (MCs) to achieve efficient immune-suppressive effects. METHODS: Three types of nanofiber hydrogel composites (Bare-Nanofibers (BNF), Nanofiber-Hydrogels (NF-Gel) and Cross-linked Nanofiber-Hydrogels (NF-Gel-X)), were evaluated. The degranulation rates of MCs were determined by measurement of the extracellular levels of hydrogen peroxide and the released amounts of ß-hexosaminidase from the activated-MCs (a-MCs). In addition, the effects of EDV on the selective scavenging of the oxygen radicals and prevention of peroxynitrite formation were evaluated. The roles of a-MCs in re-endothelialization and viability of coronary artery endothelial cells (hPCAECs) were defined using alamar blue and LDH assay, respectively. RESULTS: Each polymer matrix has unique morphological characteristics. The effects of EDV (~1.0 mM) on the production of NO were greatly influenced by the presence of superoxide or hydroxyl radicals. NF-G-X containing a mixture of EDV and S-Nitroglutathione (GSNO) produced the highest level of NO under the oxidative stress conditions. GSNO alone or a mixture of GSNO and EDV significantly lowered the degranulation rate of a-MCs (GSNO only: 55.8 ± 5.4%; GSNO with EDV: 50.6 ± 0.6%), indicating that NO plays an integral role in degranulation of a-MCs. There were no significant biochemical evidences of cytotoxic effects of GSNO and EDV on the hPCAECs. CONCLUSIONS: Nanofibers containing a mixture of nitric oxide donors and ROS scavengers could be used as a promising strategy to stabilize MCs from the ROS-mediated immune responses.

Advanced cardiovascular stent coated with nanofiber.

Nanofiber was explored as a stent surface coating substance for the treatment of coronary artery diseases (CAD). Nanofibers loaded with nanoparticles containing ß-estradiol were developed and exploited to prevent stent-induced restenosis through regulation of the reactive oxygen species (ROS). Eudragit S-100 (ES), a versatile polymer, was used as a nanoparticle (NP) base, and the mixtures of hexafluoro-2-propanol (HFIP), PLGA and PLA at varying ratios were used as a nanofiber base. ß-Estradiol was used as a primary compound to alleviate the ROS activity at the subcellular level. Nile-Red was used as a visual marker. Stent was coated with nanofibers produced by electrospinning technique comprising the two-step process. Eudragit nanoparticles (ES-NP) as well as 4 modified types of NP-W (ES-NP were dispersed in H2O, which was mixed with HFIP (1:1 (v/v) and then subsequently added with 15% PLGA), NP-HW (ES-NP were dispersed in H2O, which was mixed with HFIP (1:1 (v/v)) already containing 15% PLGA), NP-CHA (ES-NP with a chitosan layer were added in H2O, which was mixed with HFIP (1:1 (v/v)) containing 15% PLGA), and NP-CHB (ES-NP with a chitosan layer were added in H2O, which was mixed with HFIP (1:1 (v/v)) containing the mixture of PLGA and PLA at a ratio of 4:1) were developed, and their properties, such as the loading capacity of ß-estradiol, the release profiles of ß-estradiol, cell cytotoxicity and antioxidant responses to ROS, were characterized and compared. Among composite nanofibers loaded with nanoparticles, NP-CHB had the maximal yield and drug-loading amount of 66.5 ± 3.7% and 147.9 ± 10.1 µg, respectively. The nanofibers of NP-CHB coated on metallic mandrel offered the most sustained release profile of ß-estradiol. In the confocal microscopy study, NP-W exhibited a low fluorescent intensity of Nile-Red as compared with NP-HW, indicating that the stability of nanoparticles decreased, as the percentage volume of the organic solvent increased. Nanofibers incorporated with ß-estradiol yielded a high endothelial proliferation rate, which was about 3-fold greater than the control (without ß-estradiol). The cells treated with the enhanced level of H2O2 (>1 mM: as ROS source) were mostly nonviable (81.1 ± 12.4%, p < 0.01), indicating that ROS induce cell apoptosis and trigger the rupture of atheroma thin layer in a concentration dependent manner. Nanofibers containing ß-estradiol (0.5 mM) lowered cellular cytotoxicity from 25.2 ± 4.9% to 8.1 ± 1.4% in the presence of 600 µM H2O2, and from 86.8 ± 8.4% to 59.4 ± 8.7% in the presence of 1.0 mM H2O2, suggesting that ß-estradiol efficiently protected hPCECs from ROS induced cytotoxicity. The level of NO production in hPCECs in the presence of ß-estradiol after 6 days of incubation was much greater than that of the control without ß-estradiol. In summary, nanofibers loaded with nanoparticles containing ß-estradiol could be used as a suitable platform for the surface coating of a cardiovascular stent, achieving enhanced endothelialization at the implanted sites of blood vessels.

Nanofiber for cardiovascular tissue engineering.

INTRODUCTION: Organ/tissue replacement therapy is inherently difficult for application in the tissue engineering field due to immune rejection that limits the long-term efficacy of implanted devices. As the application of tissue engineering in the biomedical field has steadily expanded, stem cells have emerged as a viable option to promote the immune acceptance of implantable devices and to expedite alleviation of the pathological conditions. With various novel scaffolds being introduced, nanofibers which have a three-dimensional architecture can be considered as an efficient carrier for stem cells. AREAS COVERED: This article reviews the novel tissue engineering processes involved with nanofiber and stem cells. Topics such as the fabrication of nanofiber via electrospinning techniques, the interaction between nanofiber scaffold and specific cell and advanced techniques to enhance the stability of stem cells are delineated in detail. In addition, cardiovascular applications of nanofiber scaffolds loaded with stem cells are examined from a clinical perspective. EXPERT OPINION: Electrospun nanofibers have been intensively explored as a tool for the architecture control of cardiovascular tissue engineering due to their tunable physicochemical properties. The modification of nanofiber with biological cues, which provide rapid differentiation of stem cells into a specific lineage and protect stem cells under the harsh conditions (i.e., hypoxia), will significantly enhance therapeutic efficacies of transplanted cells. A combination of nanofiber carriers and stem cell therapy for tissue regeneration seems to pose enormous potential for the treatment of cardiac diseases including atherosclerosis and myocardial infarction.