1
|
Abstract
The global incidence and prevalence of paediatric inflammatory bowel disease (IBD) is increasing, with a notable emergence in developing countries with historically low rates. This suggests that environmental and epigenetic factors may play an important role in the pathogenesis and progression of IBD. Epigenetics refers to the study of biological mechanisms that result in a change of phenotype, without an change in the underlying DNA sequence. Epigenetic mechanisms drive many biological processes that occur in health, such as development and ageing, and are also implicated in disease, including cancer and other inflammatory diseases. Importantly, identification of cell-type-specific epigenetic mechanisms could lead to the identification of molecular disease subtypes allowing a personalised treatment approach. In this short review, we provide a summary of epigenetic mechanisms operative in mammals, and their potential involvement in IBD pathogenesis. Furthermore, we discuss key challenges associated with investigating epigenetics in IBD and provide potential strategies to overcome these, such as through the use of 'omics' and organoid technologies.
Collapse
Affiliation(s)
- Natasha G
- Paediatrics, Cambridge University, Cambridge, UK
| | | |
Collapse
|
2
|
Affiliation(s)
- Natasha G
- Department of Infectious Diseases, Addenbrookes Hospital, Cambridge, UK
| | - Elinor Moore
- Department of Infectious Diseases, Addenbrookes Hospital, Cambridge, UK
| | - Nyarie Sithole
- Department of Infectious Diseases, Addenbrookes Hospital, Cambridge, UK
| |
Collapse
|
3
|
G N, Hourston G, Thahir A, Carrothers A. Pushing the Surgical Limits: Primary Total Knee Arthroplasty Using Rotational Prosthesis in a 96-Year-Old Lady with End-Stage Osteoarthritis. Cureus 2021; 13:e13294. [PMID: 33738148 PMCID: PMC7958796 DOI: 10.7759/cureus.13294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
We present the case of a 96-year-old patient treated for severe osteoarthritis with primary total knee arthroplasty (TKA) using a rotational prosthesis. The patient had significant medical comorbidities and her independence was limited due to her severe functional immobility. This case demonstrates that TKA can be a safe procedure with good outcomes in nonagenarians with severe osteoarthritis. Thorough discussion of treatment options is crucial for elderly patients with multiple medical comorbidities. TKA in the nonagenarian population can restore function and independence for patients which may reduce the burden on social care.
Collapse
Affiliation(s)
- Natasha G
- Trauma and Orthopaedic Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambrige, GBR
| | - George Hourston
- Trauma and Orthopaedic Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, GBR
| | - Azeem Thahir
- Trauma and Orthopaedic Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, GBR
| | - Andrew Carrothers
- Trauma and Orthopaedic Surgery, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, GBR
| |
Collapse
|
4
|
G N, Chan M, Gue YX, Gorog DA. Fatal heart block from intentional yew tree ( Taxus baccata) ingestion: a case report. Eur Heart J Case Rep 2020; 4:1-4. [PMID: 32128497 PMCID: PMC7047065 DOI: 10.1093/ehjcr/ytz226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 08/15/2019] [Accepted: 11/21/2019] [Indexed: 11/14/2022]
Abstract
BACKGROUND Taxus baccata, also known as English yew, is a poison that causes cardiac arrhythmias and can result in death from cardiogenic shock. CASE SUMMARY A 49-year-old gentleman was admitted following yew ingestion with suicidal intent. He was bradycardic at 30 b.p.m. and hypotensive on arrival. Electrocardiography revealed complete heart block with broad complex ventricular escape rate of 30 b.p.m. Bedside echocardiography revealed severe global impairment of right and left ventricular systolic function. Urgent temporary transvenous pacing was instituted, and the patient was considered for veno-arterial extracorporeal membrane oxygenation. Unfortunately, he deteriorated rapidly and cardiorespiratory arrest ensued, and despite prolonged in-hospital resuscitation, the patient died. Post-mortem examination revealed small needle-shaped plant leaves together with seeds found in the stomach. Ante mortem serum sample analysis sent to the Royal Botanical Gardens and revealed the presence of taxine Type B alkaloids in the patient's blood. DISCUSSION Yew poisoning is a rare occurrence, and there is currently no effective antidote. Treatment involves supportive management, comprising prolonged effective cardiopulmonary resuscitation, pacing, and mechanical cardiac support. This case illustrates the importance of prompt recognition of yew poisoning, alongside early consideration of pacing and mechanical cardiac support. Due to the rarity of this cause of heart block, and since patients may not always volunteer a history of yew ingestion, yew poisoning is something that physicians should be aware of and this should be considered in the differential diagnosis in patients with unexpected heart block. Serum analysis for taxine alkaloids can be used to confirm the diagnosis.
Collapse
Affiliation(s)
- Natasha G
- Department of Cardiology, Lister Hospital, East and North Hertfordshire NHS Trust, Coreys Mill Lane, Stevenage SG1 4AB, UK
| | - Mark Chan
- Department of Cardiology, Lister Hospital, East and North Hertfordshire NHS Trust, Coreys Mill Lane, Stevenage SG1 4AB, UK
| | - Ying X Gue
- Department of Cardiology, Lister Hospital, East and North Hertfordshire NHS Trust, Coreys Mill Lane, Stevenage SG1 4AB, UK.,Department of Postgraduate Medicine, University of Hertfordshire, Hatfield, Hertfordshire AL10 9AB, UK
| | - Diana A Gorog
- Department of Cardiology, Lister Hospital, East and North Hertfordshire NHS Trust, Coreys Mill Lane, Stevenage SG1 4AB, UK.,Department of Postgraduate Medicine, University of Hertfordshire, Hatfield, Hertfordshire AL10 9AB, UK.,Faculty of Medicine, National Heart & Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK
| |
Collapse
|
5
|
Abstract
We present a rare case of a 4-year-old boy with newly diagnosed Henöch-Schonlein purpura (HSP) affecting the scrotum and penis. The patient presented to the emergency department with palpable purpura symmetrically distributed over the lower limbs. This was associated with arthritis of the right knee, abdominal pain and scrotal swelling. These symptoms were preceded by an upper respiratory tract infection (URTI). The patient was initially treated with empirical oral antibiotics for epididymitis and was discharged. He subsequently re-presented 12 days later with penile swelling, erythema and tenderness. An ultrasound scan of the penis revealed grossly oedematous subcutaneous tissue with normal penile architecture. His symptoms resolved spontaneously and the patient remains under close follow-up by the paediatric team for further sequelae of HSP.
Collapse
Affiliation(s)
- Andrew Brodie
- Department of Urology, Lister Hospital, Stevenage, UK
| | - Natasha G
- Department of Urology, Lister Hospital, Stevenage, UK
| | | | | |
Collapse
|
6
|
Kumar A, Tan A, Wong J, Spagnoli JC, Lam J, Blevins BD, G N, Thorne L, Ashkan K, Xie J, Liu H. Nanotechnology for Neuroscience: Promising Approaches for Diagnostics, Therapeutics and Brain Activity Mapping. Adv Funct Mater 2017; 27:1700489. [PMID: 30853878 PMCID: PMC6404766 DOI: 10.1002/adfm.201700489] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Unlocking the secrets of the brain is a task fraught with complexity and challenge - not least due to the intricacy of the circuits involved. With advancements in the scale and precision of scientific technologies, we are increasingly equipped to explore how these components interact to produce a vast range of outputs that constitute function and disease. Here, an insight is offered into key areas in which the marriage of neuroscience and nanotechnology has revolutionized the industry. The evolution of ever more sophisticated nanomaterials culminates in network-operant functionalized agents. In turn, these materials contribute to novel diagnostic and therapeutic strategies, including drug delivery, neuroprotection, neural regeneration, neuroimaging and neurosurgery. Further, the entrance of nanotechnology into future research arenas including optogenetics, molecular/ion sensing and monitoring, and piezoelectric effects is discussed. Finally, considerations in nanoneurotoxicity, the main barrier to clinical translation, are reviewed, and direction for future perspectives is provided.
Collapse
Affiliation(s)
- Anil Kumar
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Aaron Tan
- UCL Medical School, University College London (UCL), London, United Kingdom
| | - Joanna Wong
- Imperial College School of Medicine, Imperial College London,London, United Kingdom
| | - Jonathan Clayton Spagnoli
- Department of Chemistry, Bio-Imaging Research Center, University of Georgia, Athens, Georgia 30602, United States
| | - James Lam
- UCL Medical School, University College London (UCL), London, United Kingdom
| | - Brianna Diane Blevins
- Department of Chemistry, Bio-Imaging Research Center, University of Georgia, Athens, Georgia 30602, United States
| | - Natasha G
- UCL Medical School, University College London (UCL), London, United Kingdom
| | - Lewis Thorne
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
| | - Keyoumars Ashkan
- Department of Neurosurgery, King's College Hospital NHS Foundation Trust, King's College London, London, United Kingdom
| | - Jin Xie
- Department of Chemistry, Bio-Imaging Research Center, University of Georgia, Athens, Georgia 30602, United States
| | - Hong Liu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| |
Collapse
|
7
|
Tan A, Chawla R, G N, Mahdibeiraghdar S, Jeyaraj R, Rajadas J, Hamblin MR, Seifalian AM. Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier. J Plast Reconstr Aesthet Surg 2015; 69:1-13. [PMID: 26422652 DOI: 10.1016/j.bjps.2015.08.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 07/08/2015] [Accepted: 08/23/2015] [Indexed: 12/28/2022]
Abstract
The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery.
Collapse
Affiliation(s)
- Aaron Tan
- UCL Medical School, University College London (UCL), London, England, UK; Biomaterials & Advanced Drug Delivery Laboratory (BioADD), Stanford University School of Medicine, Stanford University, Stanford, CA, USA.
| | - Reema Chawla
- Department of Plastic & Reconstructive Surgery, John Radcliffe Hospital, Oxford University Hospitals NHS Trust, Oxford, England, UK
| | - Natasha G
- UCL Medical School, University College London (UCL), London, England, UK
| | - Sara Mahdibeiraghdar
- UCL Institute of Child Health, University College London (UCL), Great Ormond Street Hospital for Children NHS Foundation Trust, London, England, UK; School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - Rebecca Jeyaraj
- UCL Medical School, University College London (UCL), London, England, UK
| | - Jayakumar Rajadas
- Biomaterials & Advanced Drug Delivery Laboratory (BioADD), Stanford University School of Medicine, Stanford University, Stanford, CA, USA
| | - Michael R Hamblin
- Wellman Centre for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, USA
| | - Alexander M Seifalian
- Centre for Nanotechnology & Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London (UCL), London, England, UK; NanoRegMed Ltd, London, England, UK
| |
Collapse
|
8
|
Zia S, Mozafari M, Natasha G, Tan A, Cui Z, Seifalian AM. Hearts beating through decellularized scaffolds: whole-organ engineering for cardiac regeneration and transplantation. Crit Rev Biotechnol 2015; 36:705-15. [PMID: 25739987 DOI: 10.3109/07388551.2015.1007495] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Whole-organ decellularization and tissue engineering approaches have made significant inroads during recent years. If proven to be successful and clinically viable, it is highly likely that this field would be poised to revolutionize organ transplantation surgery. In particular, whole-heart decellularization has captured the attention and imagination of the scientific community. This technique allows for the generation of a complex three-dimensional (3D) extracellular matrix scaffold, with the preservation of the intrinsic 3D basket-weave macroarchitecture of the heart itself. The decellularized scaffold can then be recellularized by seeding it with cells and incubating it in perfusion bioreactors in order to create functional organ constructs for transplantation. Indeed, research into this strategy of whole-heart tissue engineering has consequently emerged from the pages of science fiction into a proof-of-concept laboratory undertaking. This review presents current trends and advances, and critically appraises the concepts involved in various approaches to whole-heart decellularization and tissue engineering.
Collapse
Affiliation(s)
- Sonia Zia
- a Department of Cardiothoracic Transplantation & Vascular Surgery , Hannover Medical School , Hannover , Germany
| | - Masoud Mozafari
- b Bioengineering Research Group, Nanotechnology & Advanced Materials Department , Materials & Energy Research Center (MERC) , Tehran , Iran
| | - G Natasha
- c Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science , Centre for Nanotechnology & Regenerative Medicine, University College London (UCL) , London , UK .,d UCL Medical School, University College London (UCL) , London , UK
| | - Aaron Tan
- c Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science , Centre for Nanotechnology & Regenerative Medicine, University College London (UCL) , London , UK .,d UCL Medical School, University College London (UCL) , London , UK
| | - Zhanfeng Cui
- e Department of Engineering Science , Oxford Centre for Tissue Engineering & Bioprocessing, Institute of Biomedical Engineering, University of Oxford , Oxford , UK , and
| | - Alexander M Seifalian
- c Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science , Centre for Nanotechnology & Regenerative Medicine, University College London (UCL) , London , UK .,f Royal Free London NHS Foundation Trust Hospital , London , UK
| |
Collapse
|
9
|
Bartlett R, Everett W, Lim S, G N, Loizidou M, Jell G, Tan A, Seifalian AM. Personalized in vitro cancer modeling - fantasy or reality? Transl Oncol 2014; 7:657-64. [PMID: 25500073 PMCID: PMC4311045 DOI: 10.1016/j.tranon.2014.10.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/06/2014] [Accepted: 10/13/2014] [Indexed: 01/06/2023] Open
Abstract
With greater technological advancements and understanding of pathophysiology, “personalized medicine” has become a more realistic goal. In the field of cancer, personalized medicine is the ultimate objective, as each cancer is unique and each tumor is heterogeneous. For many decades, researchers have relied upon studying the histopathology of tumors in the hope that it would provide clues to understanding the pathophysiology of cancer. Current preclinical research relies heavily upon two-dimensional culture models. However, these models have had limited success in recreating the complex interactions between cancer cells and the stroma environment in vivo. Thus, there is increasing impetus to shift to three-dimensional models, which more accurately reflect this phenomenon. With a more accurate in vitro tumor model, drug sensitivity can be tested to determine the best treatment option based on the tumor characteristics. Many methods have been developed to create tumor models or “tumoroids,” each with its advantages and limitations. One significant problem faced is the replication of angiogenesis that is characteristic of tumors in vivo. Nonetheless, if three-dimensional models could be standardized and implemented as a preclinical research tool for therapeutic testing, we would be taking a step towards making personalized cancer medicine a reality.
Collapse
Affiliation(s)
- Richard Bartlett
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; UCL Medical School, University College London (UCL), London, UK
| | - William Everett
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; UCL Medical School, University College London (UCL), London, UK
| | - Santi Lim
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; UCL Medical School, University College London (UCL), London, UK
| | - Natasha G
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; UCL Medical School, University College London (UCL), London, UK
| | - Marilena Loizidou
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK
| | - Gavin Jell
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK
| | - Aaron Tan
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; UCL Medical School, University College London (UCL), London, UK; Biomaterials & Advanced Drug Delivery Laboratory (BioADD), Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Alexander M Seifalian
- Centre for Nanotechnology & Regenerative Medicine, Research Department of Nanotechnology, UCL Division of Surgery & Interventional Science, University College London (UCL), London, UK; Royal Free London NHS Foundation Trust Hospital, London, UK.
| |
Collapse
|
10
|
G N, Tan A, Gundogan B, Farhatnia Y, Nayyer L, Mahdibeiraghdar S, Rajadas J, De Coppi P, Davies AH, Seifalian AM. Tissue engineering vascular grafts a fortiori: looking back and going forward. Expert Opin Biol Ther 2014; 15:231-44. [PMID: 25427995 DOI: 10.1517/14712598.2015.980234] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Cardiovascular diseases such as coronary heart disease often necessitate the surgical repair using conduits. Although autografts still remain the gold standard, the inconvenience of harvesting and/or insufficient availability in patients with atherosclerotic disease has given impetus to look into alternative sources for vascular grafts. AREAS COVERED There are four main techniques to produce tissue-engineered vascular grafts (TEVGs): i) biodegradable synthetic scaffolds; ii) gel-based scaffolds; iii) decellularised scaffolds and iv) self-assembled cell-sheet-based techniques. The first three techniques can be grouped together as scaffold-guided approach as it involves the use of a construct to function as a supportive framework for the vascular graft. The most significant advantages of TEVGs are that it possesses the ability to grow, remodel and respond to environmental factors. Cell sources for TEVGs include mature somatic cells, stem cells, adult progenitor cells and pluripotent stem cells. EXPERT OPINION TEVG holds great promise with advances in nanotechnology, coupled with important refinements in tissue engineering and decellularisation techniques. This will undoubtedly be an important milestone for cardiovascular medicine when it is eventually translated to clinical use.
Collapse
Affiliation(s)
- Natasha G
- University College London (UCL), Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery and Interventional Science, Research Department of Nanotechnology , London NW3 2QG , UK +44 207 830 2901 ;
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Tan A, Goh D, Farhatnia Y, G N, Lim J, Teoh SH, Rajadas J, Alavijeh MS, Seifalian AM. An anti-CD34 antibody-functionalized clinical-grade POSS-PCU nanocomposite polymer for cardiovascular stent coating applications: a preliminary assessment of endothelial progenitor cell capture and hemocompatibility. PLoS One 2013; 8:e77112. [PMID: 24116210 PMCID: PMC3793009 DOI: 10.1371/journal.pone.0077112] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/30/2013] [Indexed: 12/29/2022] Open
Abstract
In situ endothelialization of cardiovascular implants has emerged in recent years as an attractive means of targeting the persistent problems of thrombosis and intimal hyperplasia. This study aimed to investigate the efficacy of immobilizing anti-CD34 antibodies onto a POSS-PCU nanocomposite polymer surface to sequester endothelial progenitor cells (EPCs) from human blood, and to characterize the surface properties and hemocompatibility of this surface. Amine-functionalized fumed silica was used to covalently conjugate anti-CD34 to the polymer surface. Water contact angle, fluorescence microscopy, and scanning electron microscopy were used for surface characterization. Peripheral blood mononuclear cells (PBMCs) were seeded on modified and pristine POSS-PCU polymer films. After 7 days, adhered cells were immunostained for the expression of EPC and endothelial cell markers, and assessed for the formation of EPC colonies. Hemocompatibility was assessed by thromboelastography, and platelet activation and adhesion assays. The number of EPC colonies formed on anti-CD34-coated POSS-PCU surfaces was not significantly higher than that of POSS-PCU (5.0±1.0 vs. 1.7±0.6, p>0.05). However, antibody conjugation significantly improved hemocompatibility, as seen from the prolonged reaction and clotting times, decreased angle and maximum amplitude (p<0.05), as well as decreased platelet adhesion (76.8±7.8 vs. 8.4±0.7, p<0.05) and activation. Here, we demonstrate that POSS-PCU surface immobilized anti-CD34 antibodies selectively captured CD34+ cells from peripheral blood, although only a minority of these were EPCs. Nevertheless, antibody conjugation significantly improves the hemocompatibility of POSS-PCU, and should therefore continue to be explored in combination with other strategies to improve the specificity of EPC capture to promote in situ endothelialization.
Collapse
Affiliation(s)
- Aaron Tan
- Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, United Kingdom
- UCL Medical School, University College London, London, United Kingdom
| | - Debbie Goh
- Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, United Kingdom
- UCL Medical School, University College London, London, United Kingdom
| | - Yasmin Farhatnia
- Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, United Kingdom
| | - Natasha G
- Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, United Kingdom
- UCL Medical School, University College London, London, United Kingdom
| | - Jing Lim
- Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Swee-Hin Teoh
- Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jayakumar Rajadas
- Biomaterials and Advanced Drug Delivery Laboratory, School of Medicine, Stanford University, Stanford, California, United States of America
| | | | - Alexander M. Seifalian
- Centre for Nanotechnology and Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, United Kingdom
- Royal Free London NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
12
|
Tan A, Farhatnia Y, Goh D, G N, de Mel A, Lim J, Teoh SH, Malkovskiy AV, Chawla R, Rajadas J, Cousins BG, Hamblin MR, Alavijeh MS, Seifalian AM. Surface modification of a polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) nanocomposite polymer as a stent coating for enhanced capture of endothelial progenitor cells. Biointerphases 2013; 8:23. [PMID: 24706135 PMCID: PMC3979469 DOI: 10.1186/1559-4106-8-23] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 08/21/2013] [Indexed: 11/10/2022] Open
Abstract
An unmet need exists for the development of next-generation multifunctional nanocomposite
materials for biomedical applications, particularly in the field of cardiovascular
regenerative biology. Herein, we describe the preparation and characterization of a novel
polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU)
nanocomposite polymer with covalently attached anti-CD34 antibodies to enhance capture of
circulating endothelial progenitor cells (EPC). This material may be used as a new coating
for bare metal stents used after balloon angioplasty to improve re-endothelialization.
Biophysical characterization techniques were used to assess POSS-PCU and its subsequent
functionalization with anti-CD34 antibodies. Results indicated successful covalent
attachment of anti-CD34 antibodies on the surface of POSS-PCU leading to an increased
propensity for EPC capture, whilst maintaining in vitro biocompatibility
and hemocompatibility. POSS-PCU has already been used in 3 first-in-man studies, as a
bypass graft, lacrimal duct and a bioartificial trachea. We therefore postulate that its
superior biocompatibility and unique biophysical properties would render it an ideal
candidate for coating medical devices, with stents as a prime example. Taken together,
anti-CD34 functionalized POSS-PCU could form the basis of a nano-inspired polymer platform
for the next generation stent coatings.
Collapse
Affiliation(s)
- Aaron Tan
- Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, USA,
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
G N, Tan A, Farhatnia Y, Rajadas J, Hamblin MR, Khaw PT, Seifalian AM. Channelrhodopsins: visual regeneration and neural activation by a light switch. N Biotechnol 2013; 30:461-74. [PMID: 23664865 DOI: 10.1016/j.nbt.2013.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/28/2013] [Accepted: 04/16/2013] [Indexed: 01/09/2023]
Abstract
The advent of optogenetics provides a new direction for the field of neuroscience and biotechnology, serving both as a refined investigative tool and as potential cure for many medical conditions via genetic manipulation. Although still in its infancy, recent advances in optogenetics has made it possible to remotely manipulate in vivo cellular functions using light. Coined Nature Methods' 'Method of the Year' in 2010, the optogenetic toolbox has the potential to control cell, tissue and even animal behaviour. This optogenetic toolbox consists of light-sensitive proteins that are able to modulate membrane potential in response to light. Channelrhodopsins (ChR) are light-gated microbial ion channels, which were first described in green algae. ChR2 (a subset of ChR) is a seven transmembrane α helix protein, which evokes membrane depolarization and mediates an action potential upon photostimulation with blue (470 nm) light. By contrast to other seven-transmembrane proteins that require second messengers to open ion channels, ChR2 form ion channels themselves, allowing ultrafast depolarization (within 50 milliseconds of illumination). It has been shown that integration of ChR2 into various tissues of mice can activate neural circuits, control heart muscle contractions, and even restore breathing after spinal cord injury. More compellingly, a plethora of evidence has indicated that artificial expression of ChR2 in retinal ganglion cells can reinstate visual perception in mice with retinal degeneration.
Collapse
Affiliation(s)
- Natasha G
- Centre for Nanotechnology & Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London, UK
| | | | | | | | | | | | | |
Collapse
|