MICRO INJECTOR BASED ON DIGITAL DRIVE AND CONTROL FOR BIOMEDICAL ENGINEERING

Liya Hou,Weiyi Zhang,Lili Mu,Li Zhu 제어로봇시스템학회 2003 제어로봇시스템학회 국제학술대회 논문집 Vol.2003 No.10

Regulated Mesenchymal Stem Cells Mediated Colon Cancer Therapy Assessed by Reporter Gene Based Optical Imaging

Kalimuthu, Senthilkumar,Zhu, Liya,Oh, Ji Min,Lee, Ho Won,Gangadaran, Prakash,Rajendran, Ramya Lakshmi,Baek, Se Hwan,Jeon, Yong Hyun,Jeong, Shin Young,Lee, Sang-Woo,Lee, Jaetae,Ahn, Byeong-Cheol MDPI 2018 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.19 No.4

<P>Colorectal cancer is the most common cancer in both men and women and the second most common cause of cancer-related deaths. Suicide gene-based therapy with suicide gene-transduced mesenchymal stem cells (MSCs) is a promising therapeutic strategy. A tetracycline-controlled Tet-On inducible system used to regulate gene expression may be a useful tool for gene-based therapies. The aim of this study was to develop therapeutic MSCs with a suicide gene that is induced by an artificial stimulus, to validate therapeutic gene expression, and to monitor the MSC therapy for colon cancer using optical molecular imaging. For our study, we designed the Tet-On system using a retroviral vector and developed a response plasmid RetroX-TRE (tetracycline response element) expressing a mutant form of herpes simplex virus thymidine kinase (HSV1-sr39TK) with dual reporters (eGFP-Fluc2). Bone marrow-derived MSCs were transduced using a RetroX-Tet3G (Clontech, CA, USA) regulatory plasmid and RetroX-TRE-HSV1-sr39TK-eGFP-IRES-Fluc2, for a system with a Tet-On (MSC-Tet-TK/Fluc2 or MSC-Tet-TK) or without a Tet-On (MSC-TK/Fluc2 or MSC-TK) function. Suicide gene engineered MSCs were co-cultured with colon cancer cells (CT26/Rluc) in the presence of the prodrug ganciclovir (GCV) after stimulation with or without doxycycline (DOX). Treatment efficiency was monitored by assessing Rluc (CT26/Rluc) and Fluc (MSC-Tet-TK and MSC-TK) activity using optical imaging. The bystander effect of therapeutic MSCs was confirmed in CT26/Rluc cells after GCV treatment. Rluc activity in CT26/Rluc cells decreased significantly with GCV treatment of DOX(+) cells (<I>p</I> < 0.05 and 0.01) whereas no significant changes were observed in DOX(−) cells. In addition, Fluc activity in also decreased significantly with DOX(+) MSC-Tet-TK cells, but no signal was observed in DOX(−) cells. In addition, an MSC-TK bystander effect was also confirmed. We assessed therapy with this system in a colon cancer xenograft model (CT26/Rluc). We successfully transduced cells and developed a Tet-On system with the suicide gene HSV1-sr39TK. Our results confirmed the therapeutic efficiency of a suicide gene with the Tet-On system for colon cancer. In addition, our results provide an innovative therapeutic approach using the Tet-On system to eradicate tumors by administration of MSC-Tet-TK cells with DOX and GCV.</P>

In Vivo Tracking of Chemokine Receptor CXCR4-Engineered Mesenchymal Stem Cell Migration by Optical Molecular Imaging

Kalimuthu, Senthilkumar,Oh, Ji Min,Gangadaran, Prakash,Zhu, Liya,Lee, Ho Won,Rajendran, Ramya Lakshmi,Baek, Se hwan,Jeon, Yong Hyun,Jeong, Shin Young,Lee, Sang-Woo,Lee, Jaetae,Ahn, Byeong-Cheol Hindawi 2017 Stem cells international Vol.2017 No.-

<P>CXCR4, the stromal cell-derived factor-1 receptor, plays an important role in the migration of hematopoietic progenitor/stem cells to injured and inflamed areas. Noninvasive cell tracking methods could be useful for monitoring cell fate. Therefore, in this study, we evaluated the efficacy of an intravenous infusion of genetically engineered mesenchymal stem cells (MSCs) overexpressing CXC chemokine receptor 4 (CXCR4) to home to the tumor, by optical imaging. We constructed a retroviral vector containing CXCR with dual reporter genes, <I>eGFP</I> and <I>Fluc2</I>, under the control of an EF1<I>α</I> promoter (pBABE-EF1<I>α</I>-CXCR4-eGFP-IRES-Fluc2). We also developed an eGFP-Fluc2 construct in the Retro-X retroviral vector (Retro-X-eGFP-Fluc2). MSCs were transduced with retroviruses to generate CXCR4-overexpressing MSCs (MSC-CXCR4/Fluc2) and MSCs (MSC/Fluc2). CXCR4 mRNA and protein expression was confirmed by RT-PCR and Western blotting, respectively, and it was higher in MSC-CXCR4/Fluc2 than in naive MSCs. eGFP expression was confirmed by confocal microscopy. The transfected MSC-CXCR4/Fluc2 cells showed higher migratory capacity than naive MSCs observed in Transwell migration assay. The in vivo migration of CXCR4-overexpressing MSCs to MDAMB231/Rluc tumor model by BLI imaging was also confirmed. Intravenous delivery of genetically modified MSCs overexpressing CXCR4 with a <I>Fluc2</I> reporter gene may be a useful, noninvasive BLI imaging tool for tracking cell fate.</P>

The triply periodic minimal surface-based 3D printed engineering scaffold for meniscus function reconstruction

Lan Li,Peng Wang,Jing Jin,Chunmei Xie,Bin Xue,Jiancheng Lai,Liya Zhu,Qing Jiang 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: The meniscus injury is a common disease in the area of sports medicine. The main treatment for this disease is the pain relief, rather than the meniscal function recovery. It may lead to a poor prognosis and accelerate the progression of osteoarthritis. In this study, we designed a meniscal scaffold to achieve the purposes of meniscal function recovery and cartilage protection. Methods: The meniscal scaffold was designed using the triply periodic minimal surface (TPMS) method. The scaffold was simulated as a three-dimensional (3D) intact knee model using a finite element analysis software to obtain the results of different mechanical tests. The mechanical properties were gained through the universal machine. Finally, an in vivo model was established to evaluate the effects of the TPMS-based meniscal scaffold on the cartilage protection. The radiography and histological examinations were performed to assess the cartilage and bony structures. Different regions of the regenerated meniscus were tested using the universal machine to assess the biomechanical functions. Results: The TPMS-based meniscal scaffold with a larger volume fraction and a longer functional periodicity demonstrated a better mechanical performance, and the load transmission and stress distribution were closer to the native biomechanical environment. The radiographic images and histological results of the TPMS group exhibited a better performance in terms of cartilage protection than the grid group. The regenerated meniscus in the TPMS group also had similar mechanical properties to the native meniscus. Conclusion: The TPMS method can affect the mechanical properties by adjusting the volume fraction and functional periodicity. The TPMS-based meniscal scaffold showed appropriate features for meniscal regeneration and cartilage protection.

<i>In vivo</i> migration of mesenchymal stem cells to burn injury sites and their therapeutic effects in a living mouse model

Oh, Eun Jung,Lee, Ho Won,Kalimuthu, Senthilkumar,Kim, Tae Jung,Kim, Hyun Mi,Baek, Se Hwan,Zhu, Liya,Oh, Ji Min,Son, Seung Hyun,Chung, Ho Yun,Ahn, Byeong-Cheol Elsevier 2018 Journal of controlled release Vol.279 No.-

<P><B>Abstract</B></P> <P>Mesenchymal stem cell (MSC)-based therapy has emerged as a promising therapeutic strategy for tissue regeneration and repair. In this study, we non-invasively monitored the tracking of MSCs toward burn injury sites using MSCs expressing firefly luciferase (Fluc) gene in living mice, and evaluated the effects of the MSCs at the injury site. Murine MSCs co-expressing Fluc and green fluorescent protein (GFP) were established using a retroviral system (referred to as MSC/Fluc). To evaluate the ability of MSC migration toward burn injury sites, cutaneous burn injury was induced in the dorsal skin of mice. MSC/Fluc was intravenously administrated into the mice model and bioluminescence imaging (BLI) was performed to monitor MSC tracking at designated time points. BLI signals of MSC/Fluc appeared in burn injury lesions at 4 days after the cell injection and then gradually decreased. Immunoblotting analysis was conducted to determine the expression of neovascularization-related genes such as TGF-β1 and VEGF in burnt skin. The levels of TGF-β1 and VEGF were higher in the MSC/Fluc-treated group than in the burn injury group. Our observations suggested that MSCs might assist burn wound healing and that MSCs expressing Fluc could be a useful tool for optimizing MSC-based therapeutic strategies for burn wound healing.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>