1
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Takematsu E, Murphy M, Hou S, Steininger H, Alam A, Ambrosi TH, Chan CKF. Optimizing Delivery of Therapeutic Growth Factors for Bone and Cartilage Regeneration. Gels 2023; 9:gels9050377. [PMID: 37232969 DOI: 10.3390/gels9050377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 04/23/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Bone- and cartilage-related diseases, such as osteoporosis and osteoarthritis, affect millions of people worldwide, impairing their quality of life and increasing mortality. Osteoporosis significantly increases the bone fracture risk of the spine, hip, and wrist. For successful fracture treatment and to facilitate proper healing in the most complicated cases, one of the most promising methods is to deliver a therapeutic protein to accelerate bone regeneration. Similarly, in the setting of osteoarthritis, where degraded cartilage does not regenerate, therapeutic proteins hold great promise to promote new cartilage formation. For both osteoporosis and osteoarthritis treatments, targeted delivery of therapeutic growth factors, with the aid of hydrogels, to bone and cartilage is a key to advance the field of regenerative medicine. In this review article, we propose five important aspects of therapeutic growth factor delivery for bone and cartilage regeneration: (1) protection of protein growth factors from physical and enzymatic degradation, (2) targeted growth factor delivery, (3) controlling GF release kinetics, (4) long-term stability of regenerated tissues, and (5) osteoimmunomodulatory effects of therapeutic growth factors and carriers/scaffolds.
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Affiliation(s)
- Eri Takematsu
- Department of Surgery, Stanford Medicine, Stanford, CA 94305, USA
| | - Matthew Murphy
- Blond McIndoe Laboratories, School of Biological Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PR, UK
| | - Sophia Hou
- Department of Surgery, Stanford Medicine, Stanford, CA 94305, USA
| | - Holly Steininger
- School of Medicine, University of California, San Francisco, CA 94143, USA
| | - Alina Alam
- Department of Surgery, Stanford Medicine, Stanford, CA 94305, USA
| | - Thomas H Ambrosi
- Department of Orthopaedic Surgery, University of California, Davis, CA 95817, USA
| | - Charles K F Chan
- Department of Surgery, Stanford Medicine, Stanford, CA 94305, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford Medicine, Stanford, CA 94305, USA
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Luo Z, Chen S, Zhou J, Wang C, Li K, Liu J, Tang Y, Wang L. Application of aptamers in regenerative medicine. Front Bioeng Biotechnol 2022; 10:976960. [PMID: 36105606 PMCID: PMC9465253 DOI: 10.3389/fbioe.2022.976960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/08/2022] [Indexed: 12/03/2022] Open
Abstract
Regenerative medicine is a discipline that studies how to use biological and engineering principles and operation methods to repair and regenerate damaged tissues and organs. Until now, regenerative medicine has focused mainly on the in-depth study of the pathological mechanism of diseases, the further development and application of new drugs, and tissue engineering technology strategies. The emergence of aptamers has supplemented the development methods and types of new drugs and enriched the application elements of tissue engineering technology, injecting new vitality into regenerative medicine. The role and application status of aptamers screened in recent years in various tissue regeneration and repair are reviewed, and the prospects and challenges of aptamer technology are discussed, providing a basis for the design and application of aptamers in long-term transformation.
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Affiliation(s)
- Zhaohui Luo
- Youjiang Medical University for Nationalities, Baise, Guangxi, China
- Guangxi Key Laboratory of basic and translational research of Bone and Joint Degenerative Diseases, Guangxi Biomedical Materials Engineering Research Center for Bone and Joint Degenerative Diseases, Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Shimin Chen
- Guangxi Botanical Garden of Medicinal Plants, Nanning, China
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Jing Zhou
- Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Chong Wang
- School of Mechanical Engineering, Dongguan University of Technology, Dongguan, Guangdong, China
| | - Kai Li
- Academy of Orthopedics, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China
- *Correspondence: Kai Li, ; Jia Liu, ; Yujin Tang,
| | - Jia Liu
- Guangxi Key Laboratory of basic and translational research of Bone and Joint Degenerative Diseases, Guangxi Biomedical Materials Engineering Research Center for Bone and Joint Degenerative Diseases, Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
- *Correspondence: Kai Li, ; Jia Liu, ; Yujin Tang,
| | - Yujin Tang
- Guangxi Key Laboratory of basic and translational research of Bone and Joint Degenerative Diseases, Guangxi Biomedical Materials Engineering Research Center for Bone and Joint Degenerative Diseases, Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China
- *Correspondence: Kai Li, ; Jia Liu, ; Yujin Tang,
| | - Liqiang Wang
- State Key Laboratory of Metal Matrix Composites, School of Material Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
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3
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Yang M, Li CJ, Sun X, Guo Q, Xiao Y, Su T, Tu ML, Peng H, Lu Q, Liu Q, He HB, Jiang TJ, Lei MX, Wan M, Cao X, Luo XH. MiR-497∼195 cluster regulates angiogenesis during coupling with osteogenesis by maintaining endothelial Notch and HIF-1α activity. Nat Commun 2017; 8:16003. [PMID: 28685750 PMCID: PMC5504303 DOI: 10.1038/ncomms16003] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 05/17/2017] [Indexed: 02/07/2023] Open
Abstract
A specific bone vessel subtype, strongly positive for CD31 and endomucin (CD31hiEmcnhi), is identified as coupling angiogenesis and osteogenesis. The abundance of type CD31hiEmcnhi vessels decrease during ageing. Here we show that expression of the miR-497∼195 cluster is high in CD31hiEmcnhi endothelium but gradually decreases during ageing. Mice with depletion of miR-497∼195 in endothelial cells show fewer CD31hiEmcnhi vessels and lower bone mass. Conversely, transgenic overexpression of miR-497∼195 in murine endothelium alleviates age-related reduction of type CD31hiEmcnhi vessels and bone loss. miR-497∼195 cluster maintains the endothelial Notch activity and HIF-1α stability via targeting F-box and WD-40 domain protein (Fbxw7) and Prolyl 4-hydroxylase possessing a transmembrane domain (P4HTM) respectively. Notably, endothelialium-specific activation of miR-195 by intravenous injection of aptamer-agomiR-195 stimulates CD31hiEmcnhi vessel and bone formation in aged mice. Together, our study indicates that miR-497∼195 regulates angiogenesis coupled with osteogenesis and may represent a potential therapeutic target for age-related osteoporosis. H-type endothelium, defined by the high expression of CD31 and endomucin, is found in the bone where it promotes angiogenesis and osteogensis. Here Yang et al. show that the miR-497∼195 cluster regulates the generation and maintenance of the H-type endothelium by controlling the levels of Notch regulator Fbxw7 and the HIF regulator P4HTM.
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Affiliation(s)
- Mi Yang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Chang-Jun Li
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Xi Sun
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Department of Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Qi Guo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha 410008, China
| | - Ye Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
| | - Tian Su
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
| | - Man-Li Tu
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Hui Peng
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China.,Department of Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Qiong Lu
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
| | - Qing Liu
- Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Hong-Bo He
- Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Tie-Jian Jiang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
| | - Min-Xiang Lei
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
| | - Mei Wan
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Xu Cao
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Xiang-Hang Luo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, China
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Newman MR, Benoit DS. Local and targeted drug delivery for bone regeneration. Curr Opin Biotechnol 2016; 40:125-132. [PMID: 27064433 DOI: 10.1016/j.copbio.2016.02.029] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 02/17/2016] [Accepted: 02/23/2016] [Indexed: 01/08/2023]
Abstract
While experimental bone regeneration approaches commonly employ cells, technological hurdles prevent translation of these therapies. Alternatively, emulating the spatiotemporal cascade of endogenous factors through controlled drug delivery may provide superior bone regenerative approaches. Surgically placed drug depots have clinical indications. Additionally, noninvasive systemic delivery can be used as needed for poorly healing bone injuries. However, a major hurdle for systemic delivery is poor bone biodistribution of drugs. Thus, peptides, aptamers, and phosphate-rich compounds with specificity toward proteins, cells, and molecules within the regenerative bone microenvironment may enable the design of targeted carriers with bone biodistribution greater than that achieved by drug alone. These carriers, combined with osteoregenerative drugs and/or stimuli-sensitive linkers, may enhance bone regeneration while minimizing off-target tissue effects.
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Affiliation(s)
- Maureen R Newman
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA; Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA
| | - Danielle Sw Benoit
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA; Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, USA; Department of Chemical Engineering, University of Rochester, Rochester, NY, USA.
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5
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Stoll H, Kiessling H, Stelzle M, Wendel HP, Schütte J, Hagmeyer B, Avci-Adali M. Microfluidic chip system for the selection and enrichment of cell binding aptamers. BIOMICROFLUIDICS 2015; 9:034111. [PMID: 26180568 PMCID: PMC4474950 DOI: 10.1063/1.4922544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/03/2015] [Indexed: 06/04/2023]
Abstract
Aptamers are promising cell targeting ligands for several applications such as for the diagnosis, therapy, and drug delivery. Especially, in the field of regenerative medicine, stem cell specific aptamers have an enormous potential. Using the combinatorial chemistry process SELEX (Systematic Evolution of Ligands by Exponential enrichment), aptamers are selected from a huge oligonucleotide library consisting of approximately 10(15) different oligonucleotides. Here, we developed a microfluidic chip system that can be used for the selection of cell specific aptamers. The major drawbacks of common cell-SELEX methods are the inefficient elimination of the unspecifically bound oligonucleotides from the cell surface and the unspecific binding/uptake of oligonucleotides by dead cells. To overcome these obstacles, a microfluidic device, which enables the simultaneous performance of dielectrophoresis and electrophoresis in the same device, was designed. Using this system, viable cells can be selectively assembled by dielectrophoresis between the electrodes and then incubated with the oligonucleotides. To reduce the rate of unspecifically bound sequences, electrophoretic fields can be applied in order to draw loosely bound oligonucleotides away from the cells. Furthermore, by increasing the flow rate in the chip during the iterative rounds of SELEX, the selection pressure can be improved and aptamers with higher affinities and specificities can be obtained. This new microfluidic device has a tremendous capability to improve the cell-SELEX procedure and to select highly specific aptamers.
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Affiliation(s)
- Heidi Stoll
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen , Calwerstraße 7/1, 72076 Tuebingen, Germany
| | - Heiko Kiessling
- BioMEMS and Sensors Department, Natural and Medical Sciences Institute at the University of Tübingen , Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Martin Stelzle
- BioMEMS and Sensors Department, Natural and Medical Sciences Institute at the University of Tübingen , Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Hans Peter Wendel
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen , Calwerstraße 7/1, 72076 Tuebingen, Germany
| | - Julia Schütte
- BioMEMS and Sensors Department, Natural and Medical Sciences Institute at the University of Tübingen , Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Britta Hagmeyer
- BioMEMS and Sensors Department, Natural and Medical Sciences Institute at the University of Tübingen , Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Meltem Avci-Adali
- Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen , Calwerstraße 7/1, 72076 Tuebingen, Germany
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6
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Li CJ, Cheng P, Liang MK, Chen YS, Lu Q, Wang JY, Xia ZY, Zhou HD, Cao X, Xie H, Liao EY, Luo XH. MicroRNA-188 regulates age-related switch between osteoblast and adipocyte differentiation. J Clin Invest 2015; 125:1509-22. [PMID: 25751060 DOI: 10.1172/jci77716] [Citation(s) in RCA: 391] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 01/15/2015] [Indexed: 12/22/2022] Open
Abstract
Bone marrow mesenchymal stem cells (BMSCs) exhibit an age-dependent reduction in osteogenesis that is accompanied by an increased propensity toward adipocyte differentiation. This switch increases adipocyte numbers and decreases the number of osteoblasts, contributing to age-related bone loss. Here, we found that the level of microRNA-188 (miR-188) is markedly higher in BMSCs from aged compared with young mice and humans. Compared with control mice, animals lacking miR-188 showed a substantial reduction of age-associated bone loss and fat accumulation in bone marrow. Conversely, mice with transgenic overexpression of miR-188 in osterix+ osteoprogenitors had greater age-associated bone loss and fat accumulation in bone marrow relative to WT mice. Moreover, using an aptamer delivery system, we found that BMSC-specific overexpression of miR-188 in mice reduced bone formation and increased bone marrow fat accumulation. We identified histone deacetylase 9 (HDAC9) and RPTOR-independent companion of MTOR complex 2 (RICTOR) as the direct targets of miR-188. Notably, BMSC-specific inhibition of miR-188 by intra-bone marrow injection of aptamer-antagomiR-188 increased bone formation and decreased bone marrow fat accumulation in aged mice. Together, our results indicate that miR-188 is a key regulator of the age-related switch between osteogenesis and adipogenesis of BMSCs and may represent a potential therapeutic target for age-related bone loss.
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7
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He X, Chen J, Yie SM, Ye SR, Dong DD, Li K. Using a sequence of estrogen response elements as a DNA aptamer for estrogen receptors in vitro. Nucleic Acid Ther 2015; 25:152-61. [PMID: 25734367 DOI: 10.1089/nat.2014.0521] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Estrogen receptors (ERs) are overexpressed in approximately 70% of breast cancer cases, and they play an important role in tumorigenesis. ERs are strong predictive factors for measuring responses to hormonal therapies. Aptamers are short and single stranded oligonucleotides that are able to recognize target molecules with high affinity. In the present study, we selected and synthesized an oligonucleotide, which has a similar sequence to estrogen response element in the Xenopus Vitellogenin A2 gene. The synthesized oligonucleotide was evaluated by using immunostaining of paraffin-embedded breast cancer tissues and treating MCF-7 human mammary carcinoma cell line in vitro. We found that the synthesized oligonucleotide had a high binding affinity to ER similar to estradiol. Using a specific anti-ER antibody as a standard control, we showed that the synthesized oligonucleotide specifically recognized and immunostained tumor cells of breast cancer without cross-reaction with normal tissues. The overall agreement of ER detection between the anti-ER antibody and the ER aptamer was 97.1% (kappa value=0.943; 95% CI=0.879-1.006; p<0.002). Similar to tamoxifen or fulvestrant, the oligonucleotide also had an inhibitory effect on cell proliferation of MCF-7 cell line in a dose- and time-dependent fashion but had no cytotoxic effect on human normal mammary epithelial cells. Therefore, the synthesized oligonucleotide may be used as an aptamer for immunostaining of paraffin-embedded tissue sections for breast cancer diagnosis, as well as a potential ER antagonist in the treatment of breast cancer.
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Affiliation(s)
- Xu He
- 1Core Laboratory, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Jie Chen
- 1Core Laboratory, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Shang-mian Yie
- 1Core Laboratory, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.,2Research and Development Center, Sichuan HeLi Bio-pharmaceutical Co. Ltd., Sichuan HeBang Group, Chengdu, Sichuan, China
| | - Shang-rong Ye
- 2Research and Development Center, Sichuan HeLi Bio-pharmaceutical Co. Ltd., Sichuan HeBang Group, Chengdu, Sichuan, China
| | - Dan-Dan Dong
- 3Department of Pathology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Ke Li
- 3Department of Pathology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
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Avci-Adali M, Mludek K, Perle N, Stoll H, Schlensak C, Wendel HP. Importance of rigorous in vitro evaluation of prospective cell binding aptamers. Nucleic Acid Ther 2014; 24:250-7. [PMID: 25054517 DOI: 10.1089/nat.2014.0487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hitherto, several aptamers have been selected against cell surface molecules. The use of these aptamers for in vivo applications requires the prior in-depth in vitro evaluation of cell specific binding. Here, we demonstrate the in vitro tests, which are imperatively necessary to evaluate aptamers prior to in vivo applications. Exemplarily, the target binding of a chemically synthesized model aptamer containing phosphorothioate linkages was tested after the induction of the target protein expression on the cell surface by using flow cytometry. Furthermore, different cell types were used to compare the binding of the aptamer. Different single stranded DNA oligonucleotides were selected as negative controls to evaluate sequence specific binding of the aptamer to the cells. In further experiments, the aptamer binding to the target cells was determined in a mixture containing human plasma and peripheral blood cells to simulate the binding of the aptamer to target cells in human whole blood. In this study, we demonstrated the compelling necessity of the in vitro binding tests with the selected aptamers using target and non-target cells, the use of appropriate nonsense aptamers to validate the sequence specific binding of aptamers, and the evaluation of target binding in human plasma containing blood proteins and cells. Thus, we recommend the use of described methods to validate the target specific binding of newly selected aptamers prior to in vivo applications.
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Affiliation(s)
- Meltem Avci-Adali
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen , Tuebingen, Germany
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Wiraja C, Yeo D, Lio D, Labanieh L, Lu M, Zhao W, Xu C. Aptamer technology for tracking cells' status & function. MOLECULAR AND CELLULAR THERAPIES 2014; 2:33. [PMID: 26056599 PMCID: PMC4452066 DOI: 10.1186/2052-8426-2-33] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 10/16/2014] [Indexed: 02/07/2023]
Abstract
In fields such as cancer biology and regenerative medicine, obtaining information regarding cell bio-distribution, tropism, status, and other cellular functions are highly desired. Understanding cancer behaviors including metastasis is important for developing effective cancer treatments, while assessing the fate of therapeutic cells following implantation is critical to validate the efficacy and efficiency of the therapy. For visualization purposes with medical imaging modalities (e.g. magnetic resonance imaging), cells can be labeled with contrast agents (e.g. iron-oxide nanoparticles), which allows their identification from the surrounding environment. Despite the success of revealing cell biodistribution in vivo, most of the existing agents do not provide information about the status and functions of cells following transplantation. The emergence of aptamers, single-stranded RNA or DNA oligonucleotides of 15 to 60 bases in length, is a promising solution to address this need. When aptamers bind specifically to their cognate molecules, they undergo conformational changes which can be transduced into a change of imaging contrast (e.g. optical, magnetic resonance). Thus by monitoring this signal change, researchers can obtain information about the expression of the target molecules (e.g. mRNA, surface markers, cell metabolites), which offer clues regarding cell status/function in a non-invasive manner. In this review, we summarize recent efforts to utilize aptamers as biosensors for monitoring the status and function of transplanted cells. We focus on cancer cell tracking for cancer study, stem cell tracking for regenerative medicine, and immune cell (e.g. dendritic cells) tracking for immune therapy.
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Affiliation(s)
- Christian Wiraja
- />Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457 Singapore
| | - David Yeo
- />Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457 Singapore
| | - Daniel Lio
- />Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457 Singapore
| | - Louai Labanieh
- />Department of Pharmaceutical Sciences, Sue and Bill Gross Stem Cell Research Center, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697 USA
- />Department of Biomedical Engineering, Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697 USA
| | - Mengrou Lu
- />Department of Pharmaceutical Sciences, Sue and Bill Gross Stem Cell Research Center, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697 USA
- />Department of Biomedical Engineering, Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697 USA
| | - Weian Zhao
- />Department of Pharmaceutical Sciences, Sue and Bill Gross Stem Cell Research Center, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA 92697 USA
- />Department of Biomedical Engineering, Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697 USA
| | - Chenjie Xu
- />Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457 Singapore
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Avci-Adali M, Hann L, Michel T, Steinle H, Stoppelkamp S, Stang K, Narita M, Schlensak C, Wendel HP. In vitrotest system for evaluation of immune activation potential of new single-stranded DNA-based therapeutics. Drug Test Anal 2014; 7:300-8. [DOI: 10.1002/dta.1670] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 04/14/2014] [Accepted: 04/14/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Meltem Avci-Adali
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Ludmilla Hann
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Tatjana Michel
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Heidrun Steinle
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Sandra Stoppelkamp
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Katharina Stang
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Miwako Narita
- Laboratory of Hematology and Oncology, Graduate School of Health Sciences; Niigata University; Niigata Japan
| | - Christian Schlensak
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
| | - Hans P. Wendel
- Department of Thoracic, Cardiac, and Vascular Surgery; University Hospital Tuebingen; Tuebingen Germany
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11
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Avci-Adali M, Steinle H, Michel T, Schlensak C, Wendel HP. Potential capacity of aptamers to trigger immune activation in human blood. PLoS One 2013; 8:e68810. [PMID: 23935890 PMCID: PMC3720859 DOI: 10.1371/journal.pone.0068810] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/31/2013] [Indexed: 01/08/2023] Open
Abstract
Target specific short single-stranded DNA (ssDNA) molecules, called aptamers, are auspicious ligands for numerous in vivo applications. However, aptamers are synthetic molecules, which might be recognized by the immune cells in vivo and induce an activation of the innate immune system. Thus, immune activation potential of synthetic ssDNA oligonucleotides (ODNs) was determined using a well established closed-loop circulation model. Fresh human blood was incubated at 37°C for 2 or 4 hours with ssDNA ODNs (SB_ODN) or CpG ODN as positive control. Transcriptional changes were determined by microarray analyses. Blood samples containing SB_ODN demonstrated after 4 hours a significant regulation of 295 transcripts. Amongst others, CCL8, CXCL10, CCL7 and CXCL11 were highest regulated genes. Gene Ontology terms and KEGG pathway analyses exhibited that the differentially expressed genes belong to the transcripts that are regulated during an immune and inflammatory response, and were overrepresented in TLR signaling pathway. This study shows for the first time the potential of aptamers to activate immune system after systemic application into the human blood. Thus, we highly recommend performing of these preclinical tests with potential aptamer-based therapeutics.
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Affiliation(s)
- Meltem Avci-Adali
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Heidrun Steinle
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Tatjana Michel
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Christian Schlensak
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Hans P. Wendel
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen, Tuebingen, Germany
- * E-mail:
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12
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Tan W, Donovan MJ, Jiang J. Aptamers from cell-based selection for bioanalytical applications. Chem Rev 2013; 113:2842-62. [PMID: 23509854 PMCID: PMC5519293 DOI: 10.1021/cr300468w] [Citation(s) in RCA: 469] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Weihong Tan
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Biology and College of Chemistry and Chemical Engineering, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha 410082, People’s Republic of China
- Center For Research at Bio/nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611, United States
| | - Michael J. Donovan
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Biology and College of Chemistry and Chemical Engineering, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha 410082, People’s Republic of China
- Center For Research at Bio/nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611, United States
| | - Jianhui Jiang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Biology and College of Chemistry and Chemical Engineering, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha 410082, People’s Republic of China
- Center For Research at Bio/nano Interface, Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611, United States
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Abstract
Aptamers are molecules identified from large combinatorial nucleic acid libraries by their high affinity to target molecules. Due to a variety of desired properties, aptamers are attractive alternatives to antibodies in molecular biology and medical applications. Aptamers are identified through an iterative selection–amplification process known as systematic evolution of ligands by exponential enrichment (SELEX). Although SELEX is typically carried out using purified target molecules, whole live cells are also employable as selection targets. This technology, Cell-SELEX, has several advantages. For example, generated aptamers are functional with a native conformation of the target molecule on live cells, and thus, cell surface transmembrane proteins would be targets even when their purifications in native conformations are difficult. In addition, cell-specific aptamers can be obtained without any knowledge about cell surface molecules on the target cells. Here, I review the progress of Cell-SELEX technology and discuss advantages of the technology.
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Affiliation(s)
- Shoji Ohuchi
- Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo , Tokyo, Japan
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14
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Avci-Adali M, Wilhelm N, Perle N, Stoll H, Schlensak C, Wendel HP. Absolute quantification of cell-bound DNA aptamers during SELEX. Nucleic Acid Ther 2013; 23:125-30. [PMID: 23405949 DOI: 10.1089/nat.2012.0406] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In the fields of diagnosis, imaging, regenerative medicine, and drug targeting, aptamers are promising nucleic acid ligands for specific recognition and binding of whole living cells. These aptamers are selected by a combinatorial chemistry technique called cell-SELEX (Systematic Evolution of Ligands by EXponential enrichment). During this iterative procedure of in vitro selection and enzymatic amplification, the enrichment of cell binding aptamers is generally monitored by flow cytometry. This method needs the use of fluorophore-labeled oligonucleotides for detection and allows only the relative evaluation of the aptamer binding compared with the control. Here, we describe the development and validation of a new quantitative real time polymerase chain reaction (qPCR) method for the absolute determination of cell bound aptamers during cell-SELEX. The method is based on SYBR Green I real-time PCR technology and uses an aptamer standard curve to determine the accurate aptamer amount on cells after the incubations. Lysates of cells with bound aptamers were used to identify the absolute amount of aptamers on cells. This method is highly sensitive and allows the detection of very small quantities of aptamers in cell lysate samples. The lower detection limit is 20 fg. The established qPCR method can be used as an additional monitoring tool during cell-SELEX to determine the enrichment of cell binding aptamers on cells, whereby the absolute quantity is determined. Furthermore, the contamination of the amplified aptamer pool with by-products can be prevented by prior determination of bound aptamer amount on cells.
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Affiliation(s)
- Meltem Avci-Adali
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital Tuebingen , Tuebingen, Germany
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15
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Wang P, Yang Y, Hong H, Zhang Y, Cai W, Fang D. Aptamers as therapeutics in cardiovascular diseases. Curr Med Chem 2012; 18:4169-74. [PMID: 21848510 DOI: 10.2174/092986711797189673] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 05/26/2011] [Accepted: 05/28/2011] [Indexed: 12/18/2022]
Abstract
With many advantages over other therapeutic agents such as monoclonal antibodies, aptamers have recently emerged as a novel and powerful class of ligands with excellent potential for diagnostic and therapeutic applications. Typically generated through Systematic Evolution of Ligands by EXponential enrichment (SELEX), aptamers have been selected against a wide range of targets such as proteins, phospholipids, sugars, nucleic acids, as well as whole cells. DNA/RNA aptamers are single-stranded DNA/RNA oligonucleotides (with a molecular weight of 5-40 kDa) that can fold into well-defined 3D structures and bind to their target molecules with high affinity and specificity. A number of strategies have been adopted to synthesize aptamers with enhanced in vitro/in vivo stability, aiming at potential therapeutic/diagnostic applications in the clinic. In cardiovascular diseases, aptamers can be developed into therapeutic agents as anti-thrombotics, anti-coagulants, among others. This review focuses on aptamers that were selected against various molecular targets involved in cardiovascular diseases: von Willebrand factor (vWF), thrombin, factor IX, phospholamban, P-selectin, platelet-derived growth factor, integrin α(v)β(3), CXCL10, vasopressin, among others. With continued effort in the development of aptamer-based therapeutics, aptamers will find their niches in cardiovascular diseases and significantly impact clinical patient management.
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Affiliation(s)
- P Wang
- Department of Gastroenterology, Southwest Hospital, The Third Military Medical University, Chongqing, China
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16
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Hong H, Goel S, Zhang Y, Cai W. Molecular imaging with nucleic acid aptamers. Curr Med Chem 2012; 18:4195-205. [PMID: 21838686 DOI: 10.2174/092986711797189691] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 06/22/2011] [Accepted: 06/22/2011] [Indexed: 01/16/2023]
Abstract
With many desirable properties such as ease of synthesis, small size, lack of immunogenicity, and versatile chemistry, aptamers represent a class of targeting ligands that possess tremendous potential in molecular imaging applications. Non-invasive imaging of various disease markers with aptamer-based probes has many potential clinical applications such as lesion detection, patient stratification, treatment monitoring, etc. In this review, we will summarize the current status of molecular imaging with aptamer-based probes. First, fluorescence imaging will be described which include both direct targeting and activatable probes. Next, we discuss molecular magnetic resonance imaging and targeted ultrasound investigations using aptamer-based agents. Radionuclide-based imaging techniques (single-photon emission computed tomography and positron emission tomography) will be summarized as well. In addition, aptamers have also been labeled with various tags for computed tomography, surface plasmon resonance, dark-field light scattering microscopy, transmission electron microscopy, and surface-enhanced Raman spectroscopy imaging. Among all molecular imaging modalities, no single modality is perfect and sufficient to obtain all the necessary information for a particular question. Thus, a multimodality probe has also been constructed for concurrent fluorescence, gamma camera, and magnetic resonance imaging in vivo. Although the future of aptamer-based molecular imaging is becoming increasingly bright and many proof-of-principle studies have already been reported, much future effort needs to be directed towards the development of clinically translatable aptamer-based imaging agents which will eventually benefit patients.
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Affiliation(s)
- H Hong
- Department of Radiology, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705-2275, USA
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17
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Veiseh O, Kievit FM, Ellenbogen RG, Zhang M. Cancer cell invasion: treatment and monitoring opportunities in nanomedicine. Adv Drug Deliv Rev 2011; 63:582-96. [PMID: 21295093 DOI: 10.1016/j.addr.2011.01.010] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/20/2011] [Accepted: 01/25/2011] [Indexed: 12/19/2022]
Abstract
Cell invasion is an intrinsic cellular pathway whereby cells respond to extracellular stimuli to migrate through and modulate the structure of their extracellular matrix (ECM) in order to develop, repair, and protect the body's tissues. In cancer cells this process can become aberrantly regulated and lead to cancer metastasis. This cellular pathway contributes to the vast majority of cancer related fatalities, and therefore has been identified as a critical therapeutic target. Researchers have identified numerous potential molecular therapeutic targets of cancer cell invasion, yet delivery of therapies remains a major hurdle. Nanomedicine is a rapidly emerging technology which may offer a potential solution for tackling cancer metastasis by improving the specificity and potency of therapeutics delivered to invasive cancer cells. In this review we examine the biology of cancer cell invasion, its role in cancer progression and metastasis, molecular targets of cell invasion, and therapeutic inhibitors of cell invasion. We then discuss how the field of nanomedicine can be applied to monitor and treat cancer cell invasion. We aim to provide a perspective on how the advances in cancer biology and the field of nanomedicine can be combined to offer new solutions for treating cancer metastasis.
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Affiliation(s)
- Omid Veiseh
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120, USA
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18
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Optical and magnetic resonance imaging as complementary modalities in drug discovery. Future Med Chem 2011; 2:317-37. [PMID: 21426169 DOI: 10.4155/fmc.09.175] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Imaging has the ability to study various biological and chemical processes noninvasively in living subjects in a longitudinal way. For this reason, imaging technologies have become an integral part of the drug-discovery and development program and are commonly used in following disease processes and drug action in both preclinical and clinical stages. As the domain of imaging sciences transitions from anatomical/functional to molecular applications, the development of molecular probes becomes crucial for the advancement of the field. This review summarizes the role of two complementary techniques, magnetic resonance and fluorescence optical imaging, in drug discovery. While the first approach exploits intrinsic tissue characteristics as the source of image contrast, the second necessitates the use of appropriate probes for signal generation. The anatomical, functional, metabolic and molecular information that becomes accessible through imaging can provide invaluable insights into disease mechanisms and mechanisms of drug action.
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19
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Regeneration of cartilage and bone by defined subsets of mesenchymal stromal cells--potential and pitfalls. Adv Drug Deliv Rev 2011; 63:342-51. [PMID: 21184789 DOI: 10.1016/j.addr.2010.12.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/08/2010] [Accepted: 12/10/2010] [Indexed: 01/09/2023]
Abstract
Mesenchymal stromal cells, also referred to as mesenchymal stem cells, can be obtained from various tissues. Today the main source for isolation of mesenchymal stromal cells in mammals is the bone marrow. Mesenchymal stromal cells play an important role in tissue formation and organogenesis during embryonic development. Moreover, they provide the cellular and humoral basis for many processes of tissue regeneration and wound healing in infancy, adolescence and adulthood as well. There is increasing evidence that mesenchymal stromal cells from bone marrow and other sources including term placenta or adipose tissue are not a homogenous cell population. Only a restricted number of appropriate stem cells markers have been explored so far. But routine preparations of mesenchymal stromal cells contain phenotypically and functionally distinct subsets of stromal cells. Knowledge on the phenotypical characteristics and the functional consequences of such subsets will not only extend our understanding of stem cell biology, but might allow to develop improved regimen for regenerative medicine and wound healing and novel protocols for tissue engineering as well. In this review we will discuss novel strategies for regenerative medicine by specific selection or separation of subsets of mesenchymal stromal cells in the context of osteogenesis and bone regeneration. Mesenchymal stromal cells, which express the specific cell adhesion molecule CD146, also known as MCAM or MUC18, are prone for bone repair. Other cell surface proteins may allow the selection of chondrogenic, myogenic, adipogenic or other pre-determined subsets of mesenchymal stromal cells for improved regenerative applications as well.
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21
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22
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López-Colón D, Jiménez E, You M, Gulbakan B, Tan W. Aptamers: turning the spotlight on cells. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2011; 3:328-40. [PMID: 21412992 DOI: 10.1002/wnan.133] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This article is a review of the development and application of aptamer probes for cell imaging. Aptamers selected against whole cells have been modified with different fluorescent dyes and nanomaterials, such as gold nanoparticles, quantum dots, and superparamagnetic iron oxide, for their use as imaging probes of live cells. These probes have been successfully used for cell imaging both in vitro and in vivo by optical imaging, magnetic resonance imaging (MRI), computed tomography (CT), and positron-emission tomography (PET). In this article, we discuss the development of different aptamer-based probes currently available for imaging of live cells and their applications in the biomedical field.
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Affiliation(s)
- Dalia López-Colón
- Department of Chemistry, University of Florida, Gainesville, FL, USA
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23
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Tario JD, Muirhead KA, Pan D, Munson ME, Wallace PK. Tracking immune cell proliferation and cytotoxic potential using flow cytometry. Methods Mol Biol 2011; 699:119-64. [PMID: 21116982 PMCID: PMC4371793 DOI: 10.1007/978-1-61737-950-5_7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the second edition of this series, we described the use of cell tracking dyes in combination with tetramer reagents and traditional phenotyping protocols to monitor levels of proliferation and cytokine production in antigen-specific CD8(+) T cells. In particular, we illustrated how tracking dye fluorescence profiles could be used to ascertain the precursor frequencies of different subsets in the T-cell pool that are able to bind tetramer, synthesize cytokines, undergo antigen-driven proliferation, and/or carry out various combinations of these functional responses.Analysis of antigen-specific proliferative responses represents just one of many functions that can be monitored using cell tracking dyes and flow cytometry. In this third edition, we address issues to be considered when combining two different tracking dyes with other phenotypic and viability probes for the assessment of cytotoxic effector activity and regulatory T-cell functions. We summarize key characteristics of and differences between general protein- and membrane-labeling dyes, discuss determination of optimal staining concentrations, and provide detailed labeling protocols for both dye types. Examples of the advantages of two-color cell tracking are provided in the form of protocols for (a) independent enumeration of viable effector and target cells in a direct cytotoxicity assay and (b) simultaneous monitoring of proliferative responses in effector and regulatory T cells.
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Affiliation(s)
- Joseph D Tario
- Department of Flow and Image Cytometry, Roswell Park Cancer Institute, Buffalo, NY, USA
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24
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Avci-Adali M, Metzger M, Perle N, Ziemer G, Wendel HP. Pitfalls of cell-systematic evolution of ligands by exponential enrichment (SELEX): existing dead cells during in vitro selection anticipate the enrichment of specific aptamers. Oligonucleotides 2010; 20:317-23. [PMID: 21133818 DOI: 10.1089/oli.2010.0253] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Aptamers represent auspicious ligands for recognition of target molecules on the surface of a specific cell population, such as stem or cancer cells. These ligands are able to capture and enrich desired cells from a cell mixture, and can be used for identification of new biomarkers, development of cell-specific therapeutics, and stem cell therapy. In this study, we investigated the influence of dead cells on single-stranded DNA (ssDNA) binding and established a method to eliminate dead cells from a cell suspension. Flow cytometry analyses demonstrated that all dead cells were stained with fluorescein-labeled ssDNA molecules. The increasing of the proportion of dead cells led to an increased number of cells that were positive for ssDNA staining. Using dead cell removal microbeads, the proportion of dead cells was significantly reduced. The studies demonstrated that dead cells lead to unspecific uptake/binding of ssDNA molecules during cell-Systematic Evolution of Ligands by Exponential enrichment (SELEX) and can cause failure of the selection process. Thus, the elimination of dead cell population before incubation with ssDNA molecules will reduce the loss of target binding sequences and the contamination of the enriched aptamer pool with unspecific ssDNA molecules caused by unspecific binding to dead cells.
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Affiliation(s)
- Meltem Avci-Adali
- Clinical Research Laboratory, Department of Congenital and Pediatric Cardiac Surgery, University Children's Hospital Tuebingen, Tuebingen, Germany
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25
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Kim Y, Liu C, Tan W. Aptamers generated by Cell SELEX for biomarker discovery. Biomark Med 2010; 3:193-202. [PMID: 20477510 DOI: 10.2217/bmm.09.5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Biomarker discovery is essential to the advancement of our knowledge about diseases and to the development of new strategies for treatment and therapy. Among the newest technologies in this rapidly growing field is a process termed Cell SELEX by which a panel of aptamers can be generated to specifically target disease cells. Thus, Cell SELEX, together with the in vitro selection of aptamers, brings a promising approach to accelerate the progress of biomarker discovery. In this review, the Cell SELEX method and potential uses of selected aptamers are discussed. In addition, identification of potential biomarkers by using cell-binding aptamers is addressed. We believe that using the Cell SELEX strategy represents a significant improvement over current approaches to biomarker identification by the simplicity, efficiency and specificity of its application.
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Affiliation(s)
- Youngmi Kim
- Department of Chemistry & Department of Physiology & Functional Genomics, Department of Pathology & Laboratory Medicine, Shands Cancer Center & Center for Research at the Bio/nano Interface, UF Genetics Institute & McKnight Brain Institute, University of Florida, Gainesville, FL 32611-37200, USA
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26
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Schäfer R. Labeling and Imaging of Stem Cells - Promises and Concerns. ACTA ACUST UNITED AC 2010; 37:85-89. [PMID: 20737050 DOI: 10.1159/000287271] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 02/08/2010] [Indexed: 11/19/2022]
Abstract
For experimental and clinical applications of stem cells cell labeling and tracking is interesting to evaluate cell distribution and homing. Tracking of cells after transplantation can be performed for monitoring the delivery and faith of the graft. Furthermore, imaging techniques are part of the evaluation of the functional effects of cellular therapy in the organism of the host. Therefore, systematic investigations on the development and clinical evaluation of imaging techniques and their possible biological impact on stem cells is an emerging topic of today's applied stem cell research. This article refers to different labeling techniques of stem cells highlighting their promises for clinical use and discussing their possible risks.
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Affiliation(s)
- Richard Schäfer
- Institute of Clinical and Experimental Transfusion Medicine, University Hospital Tuebingen, Germany
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27
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Veiseh O, Gunn JW, Zhang M. Design and fabrication of magnetic nanoparticles for targeted drug delivery and imaging. Adv Drug Deliv Rev 2010; 62:284-304. [PMID: 19909778 DOI: 10.1016/j.addr.2009.11.002] [Citation(s) in RCA: 1058] [Impact Index Per Article: 75.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Accepted: 10/17/2009] [Indexed: 12/13/2022]
Abstract
Magnetic nanoparticles (MNPs) represent a class of non-invasive imaging agents that have been developed for magnetic resonance (MR) imaging. These MNPs have traditionally been used for disease imaging via passive targeting, but recent advances have opened the door to cellular-specific targeting, drug delivery, and multi-modal imaging by these nanoparticles. As more elaborate MNPs are envisioned, adherence to proper design criteria (e.g. size, coating, molecular functionalization) becomes even more essential. This review summarizes the design parameters that affect MNP performance in vivo, including the physicochemical properties and nanoparticle surface modifications, such as MNP coating and targeting ligand functionalizations that can enhance MNP management of biological barriers. A careful review of the chemistries used to modify the surfaces of MNPs is also given, with attention paid to optimizing the activity of bound ligands while maintaining favorable physicochemical properties.
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Affiliation(s)
- Omid Veiseh
- Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195-2120, USA
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28
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Paul A, Avci-Adali M, Ziemer G, Wendel HP. Streptavidin-coated magnetic beads for DNA strand separation implicate a multitude of problems during cell-SELEX. Oligonucleotides 2009; 19:243-54. [PMID: 19732022 DOI: 10.1089/oli.2009.0194] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Using whole living cells as a target for SELEX (systematic evolution of ligands by exponential enrichment) experiments represents a promising method to generate cell receptor-specific aptamers. These aptamers have a huge potential in diagnostics, therapeutics, imaging, regenerative medicine, and target validation. During the SELEX for selecting DNA aptamers, one important step is the separation of 2 DNA strands to yield one of the 2 strands as single-stranded DNA aptamer. This is being done routinely by biotin labeling of the complementary DNA strand to the desired aptamer and then separating the DNA strand by using streptavidin-coated magnetic beads. After immobilization of the double-stranded DNA on these magnetic beads and alkaline denaturation, the non-biotinylated strand is being eluted and the biotinylated strand is retarded. Using Western blot analysis, we demonstrated the detachment of covalent-bonded streptavidin from the bead surface after alkaline treatment. The eluates were also contaminated with undesired biotinylated strands. Furthermore, a streptavidin-induced aggregation of target cells was demonstrated by flow cytometry and microscopic methods. Cell-specific enrichment of aptamers was not possible due to clustering and patching effects triggered by streptavidin. Therefore, the use of streptavidin-coated magnetic beads for DNA strand separation should be examined thoroughly, especially for cell-SELEX applications.
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Affiliation(s)
- Angela Paul
- Department of Thoracic, Cardiac, and Vascular Surgery, University Hospital, Tübingen 72076, Germany
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29
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Schäfer R, Dominici M, Müller I, Horwitz E, Asahara T, Bulte JWM, Bieback K, Le Blanc K, Bühring HJ, Capogrossi MC, Dazzi F, Gorodetsky R, Henschler R, Handgretinger R, Kajstura J, Kluger PJ, Lange C, Luettichau IV, Mertsching H, Schrezenmeier H, Sievert KD, Strunk D, Verfaillie C, Northoff H. Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany. Cytotherapy 2009; 11:245-55. [PMID: 19152153 DOI: 10.1080/14653240802582117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
From 4 to 5 April 2008, international experts met for the second time in Tubingen, Germany, to present and discuss the latest proceedings in research on non-hematopoietic stem cells (NHSC). This report presents issues of basic research including characterization, isolation, good manufacturing practice (GMP)-like production and imaging as well as clinical applications focusing on the regenerative and immunomodulatory capacities of NHSC.
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Affiliation(s)
- R Schäfer
- Institute of Clinical and Experimental Transfusion Medicine, University Hospital Tubingen, Germany.
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30
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Bernsen MR, Moelker AD, Wielopolski PA, van Tiel ST, Krestin GP. Labelling of mammalian cells for visualisation by MRI. Eur Radiol 2009; 20:255-74. [DOI: 10.1007/s00330-009-1540-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 06/11/2009] [Accepted: 06/23/2009] [Indexed: 12/21/2022]
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31
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Abstract
Aptamers are small single-stranded nucleic acids that fold into a well-defined three-dimensional structure. They show a high affinity and specificity for their target molecules and inhibit their biological functions. Aptamers belong to the nucleic acids family and can be synthesized by chemical or enzymatic procedures, or a combination of the two. They can, therefore, be considered as both chemical and biological substances. This Review summarizes the most convenient approaches to their preparation and new developments in the field of aptamers. The application of aptamers in chemical biology is also discussed.
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Affiliation(s)
- Günter Mayer
- Life and Medical Sciences, Prog. Unit Chemical Biology and Medicinal Chemistry, University of Bonn c/o Kekulé-Institute for Organic Chemistry and Biochemistry, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
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33
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Rojewski MT, Weber BM, Schrezenmeier H. Phenotypic Characterization of Mesenchymal Stem Cells from Various Tissues. ACTA ACUST UNITED AC 2008; 35:168-184. [PMID: 21547115 DOI: 10.1159/000129013] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Accepted: 04/23/2008] [Indexed: 12/29/2022]
Abstract
SUMMARY: Research on expanded human stem cells has become an increasing field of interest during the last decade. The increasing interest in adult stem cells, especially mesenchymal stem and mesenchymal stromal cells, in hematology and regenerative medicine is also based on the simplicity of isolation and ex vivo expansion of these cells. These processes require an adequate quality control of source and product. In this review, we summarize various different attempts to characterize mesenchymal stem cells based on surface protein expression by flow cytometry and to define multipotent subpopulations of mesenchymal stem cells for prospective isolation. The importance of defining functional assays and a unique marker panel to characterize mesenchymal stem cells for clinical trials as well as the factors that can modulate the marker expression is discussed.
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Affiliation(s)
- Markus Thomas Rojewski
- Universität Ulm, Institut für Transfusionsmedizin und Institut für Klinische Transfusionsmedizin und Immungenetik gemeinnützige GmbH, DRK Blutspendedienst Baden-Württemberg - Hessen, Ulm, Germany
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34
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Guo KT, Paul A, Schichor C, Ziemer G, Wendel HP. CELL-SELEX: Novel perspectives of aptamer-based therapeutics. Int J Mol Sci 2008; 9:668-678. [PMID: 19325777 PMCID: PMC2635693 DOI: 10.3390/ijms9040668] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 04/03/2008] [Accepted: 04/24/2008] [Indexed: 12/15/2022] Open
Abstract
Aptamers, single stranded DNA or RNA molecules, generated by a method called SELEX (systematic evolution of ligands by exponential enrichment) have been widely used in various biomedical applications. The newly developed Cell-SELEX (cell based-SELEX) targeting whole living cells has raised great expectations for cancer biology, -therapy and regenerative medicine. Combining nanobiotechnology with aptamers, this technology opens the way to more sophisticated applications in molecular diagnosis. This paper gives a review of recent developments in SELEX technologies and new applications of aptamers.
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Affiliation(s)
- Ke-Tai Guo
- Department of Thoracic, Cardiac and Vascular surgery, University Hospital Tuebingen, Calwerstr.7/1, D72076 Tuebingen, Germany
| | - Angela Paul
- Department of Thoracic, Cardiac and Vascular surgery, University Hospital Tuebingen, Calwerstr.7/1, D72076 Tuebingen, Germany
| | - Christian Schichor
- Department of Neurosurgery, Ludwig-Maximilians-University, Klinikum Grosshadern, Marchioninistr. 15, D81377 Munich, Germany
| | - Gerhard Ziemer
- Department of Thoracic, Cardiac and Vascular surgery, University Hospital Tuebingen, Calwerstr.7/1, D72076 Tuebingen, Germany
| | - Hans P. Wendel
- Department of Thoracic, Cardiac and Vascular surgery, University Hospital Tuebingen, Calwerstr.7/1, D72076 Tuebingen, Germany
- Author to whom correspondence should be addressed; E-mail:
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