Browsing by Author "Zhou, Shukui"

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A Graphene Oxide Coated Gold Nanostar Based Sensing Platform for Ultrasensitive Electrochemical Detection of Circulating Tumor DNA
(Analytical Methods, 2020) Rahman, Mahbubur; Cui, Daxiang; Zhou, Shukui; Zhang, Amin; Chen, Di
A high-performance electrochemical sensing platform inspired by a functional ‘green’ electrochemical reduction pathway was developed to identify and detect circulating tumor DNA (ctDNA) of gastric carcinoma in peripheral blood. The assembly of the biosensor, consisting of graphene oxide-wrapped gold nanostars (GO-AuNSs), was fabricated on a glassy carbon electrode using the surface chemistry of ‘layer-by-layer’ modification via an electrochemical route. The electrodeposition of the GO-AuNS nanocomposite on the electrode's surface effectively improved its electrochemical response and enhanced its immobilization pathway. At the same time, it demonstrated the electrochemical phenomena caused by DNA immobilization and hybridization events sans complex labelling or other indicators. The immobilization of the probe DNA occurred due to the π–π (weak) interactions between the GO-AuNS composite and the DNA bases. The hybridization of the probe DNA with ctDNA resulted in the formation of a helix structure, which precipitated the release of the resulting dsDNA from the electrode's surface. The immobilization and hybridization events caused a ‘signal off’ and ‘signal on’ model by respectively decreasing and increasing the signal current. The prepared composite nanostructure and the subsequently modified electrodes were characterized using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The electrochemical response of the biosensor was elucidated using Differential Pulse Voltammetry (DPV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS). A linear relationship was established between the oxidation peak currents (DPV) and the different concentrations of ctDNA within the range of 1.0 × 10−20 M to 1.0 × 10−12 M (R2 = 0.998), with a detection limit (LOD) of 1.0 × 10−20 M (S/N = 3). The developed method shows translational prospects in ctDNA detection.
Magnetic Targeting of Super-paramagnetic Iron Oxide Nanoparticle Labeled Myogenic-induced Adipose-derived Stem Cells in a Rat Model of Stress Urinary Incontinence
(Nanomedicine: Nanotechnology, Biology, and Medicine, Elsevier, 2020-08-05) Wang, Ying; Zhou, Shukui; Yang, Ranxing; Rahman, Mahbubur; Sequeira, Russel Clive; Cao, Nailong; Zhang, Yang; Zhao, Weixin; Fu, Qiang
Cell-based injectable therapy utilizing stem cells is a promising approach for the treatment of stress urinary incontinence (SUI). Applying a magnetically controlled cell delivery approach has enormous potential to enhance cell retention capability within the specified site. To assess the therapeutic efficacy of cellular magnetic targeting, we applied an external magnetic force to target an adipose-derived stem cell based therapy in a rat model of SUI. The results revealed that magnetic attraction of transplanted cells under the magnetic field was generated by cell uptake of superparamagnetic iron oxide nanoparticles in vitro. More importantly, magnetic targeting improved the retention rate of transplanted cells and facilitated the restoration of sphincter structure and function in a rat SUI model according to the results of histological examination and urodynamic testing. Therefore, magnetically guided targeting strategy might be a potential therapy method for treatment of SUI.
The Fabrication and Evaluation of a Potential Biomaterial Produced with Stem Cell Sheet Technology for Future Regenerative Medicine
(Scopus, 2020) Zhou, Shukui; Wang, Ying; Zhang, Kaile; Cao, Nailong; Yang, Ranxing; Huang, Jianwen; Zhao, Weixin; Rahman, Mahbubur; Liao, Hong; Fu, Qiang
To date, the decellularized scaffold has been widely explored as a source of biological scaffolds for regenerative medicine. However, the acellular matrix derived from natural tissues and organs has a lot of defects, including the limited amount of autogenous tissue and surgical complication such as risk of blood loss, wound infection, pain, shock, and functional damage in the donor part of the body. In this study, we prepared acellular matrix using adipose-derived stem cell (ADSC) sheets and evaluate the cellular compatibility and immunoreactivity. The ADSC sheets were fabricated and subsequently decellularized using repeated freeze-thaw, Triton X-100 and SDS decellularization. Oral mucosal epithelial cells were seeded onto the decellularized ADSC sheets to evaluate the cell replantation ability, and silk fibroin was used as the control. Then, acellular matrix was transplanted onto subcutaneous tissue for 1 week or 3 weeks; H&E staining and immunohistochemical analysis of CD68 expression and quantitative real-time PCR (qPCR) were performed to evaluate the immunogenicity and biocompatibility. The ADSC sheet-derived ECM scaffolds preserved the three-dimensional architecture of ECM and retained the cytokines by Triton X-100 decellularization protocols. Compared with silk fibroin in vitro, the oral mucosal epithelial cells survived better on the decellularized ADSC sheets with an intact and consecutive epidermal cellular layer. Compared with porcine small intestinal submucosa (SIS) in vivo, the homogeneous decellularized ADSC sheets had less monocyte-macrophage infiltrating in vivo implantation. During 3 weeks after transplantation, the mRNA expression of cytokines, such as IL-4/IL-10, was obviously higher in decellularized ADSC sheets than that of porcine SIS. A Triton X-100 method can achieve effective cell removal, retain major ECM components, and preserve the ultrastructure of ADSC sheets. The decellularized ADSC sheets possess good recellularization capacity and excellent biocompatibility. This study demonstrated the potential suitability of utilizing acellular matrix from ADSC sheets for soft tissue regeneration and repair.
Use of Bioactive Extracellular Matrix Fragments as a Urethral Bulking Agent to Treat Stress Urinary Incontinence
(Scopus, 2020) Wang, Ying; Duan, Meng; Rahman, Mahbubur; Yang, Ming; Zhao, Weixin; Zhou, Shukui; Gao, Guo; Fu, Qiang
Injection of urethral bulking agents is a low-risk, minimally invasive surgical procedure to treat stress urinary incontinence (SUI). In this study, we developed a promising injectable bulking agent comprising extracellular matrix fragments of adipose-derived stem cell sheets (ADSC ECM) and investigated its effectiveness in urethral bulking therapy. The structural integrity and proteins of ADSC sheet ECM were well retained in decellularized ADSC ECM fragments. To locate transplanted ADSC ECM fragments, they were labeled with ultrasmall super-paramagnetic iron oxide nanoparticles, which enabled in vivo monitoring after implantation in a SUI rat model for up to 4 weeks. When ADSC ECM fragments were injected into the rat urethra, they became fully integrated with the surrounding tissue within 1 week. Four weeks after transplantation, host cells had regenerated within the ADSC ECM fragment injection area. Moreover, new smooth muscle tissue had formed around the ADSC ECM fragments, as confirmed by positive staining of myosin. These results indicate that injection of ECM fragments may be a promising minimally invasive approach for treating SUI.