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Swenson TL, Ehsanian R, Tran RT, Petersen TR, Kennedy DJ, Roche M, Oppezzo M, Noordsy DL, Fredericson M. The Association Between Well-Being and Empathy in Medical Residents: A Cross-Sectional Survey. J Integr Complement Med 2024. [PMID: 38416862 DOI: 10.1089/jicm.2023.0116] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
Objective: To evaluate the extent to which personal well-being may be associated with empathy, while controlling for potential confounders. Settings/Location: Residency programs throughout the United States. Subjects: A total of 407 medical residents from residencies including general medicine, surgery, specialized and diagnostic medicine participated in this study. Outcome Measures: Well-being was measured using the modified existential well-being subscale of the spiritual well-being scale. Empathy was measured using the Jefferson Scale of Empathy. Results: Well-being was found to be positively correlated with empathy when adjusted for possible confounders (p < 0.001). In addition to well-being, other factors noted to be statistically significant contributors to higher empathy scores while controlling for the others included age, gender, year in residency, specialty, and work-hours (p < 0.05 for each). After controlling for these factors, a resident's year in residency was not found to be a statistically significant contributor to empathy score. Conclusions: In this study, well-being was associated with empathy in medical and surgical residents. Empathy is a fundamental component of physician competency, and its development is an essential aspect of medical training. These findings suggest that efforts to increase well-being may promote empathy among medical residents.
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Affiliation(s)
- Theodora L Swenson
- Department of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Reza Ehsanian
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Richard T Tran
- University of Colorado School of Medicine, Aurora, CO, USA
| | - Timothy R Petersen
- Department of Anesthesiology and Critical Care Medicine, Department of Obstetrics and Gynecology, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - David J Kennedy
- Department of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Megan Roche
- Stanford University School of Medicine, Stanford, CA, USA
| | - Marily Oppezzo
- Division of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Douglas L Noordsy
- Division of Psychiatry, Stanford University School of Medicine, Stanford, CA, USA
| | - Michael Fredericson
- Division of Physical Medicine and Rehabilitation, Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA, USA
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Tran RT, Swenson TL. Pain, Palliative Care, and Practicing Empathy. Acad Med 2024; 99:159. [PMID: 37910848 DOI: 10.1097/acm.0000000000005541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
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Swenson TL, Roehmer C, Tran RT, Schaaf S. Longitudinal Cadaver-Based Training Curriculum for Musculoskeletal Ultrasound-Guided Procedures Among Physical Medicine and Rehabilitation Residents. Am J Phys Med Rehabil 2023; 102:e36-e39. [PMID: 36166655 DOI: 10.1097/phm.0000000000002113] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
ABSTRACT Musculoskeletal ultrasound has become a fundamental diagnostic and treatment tool in the field of physical medicine and rehabilitation. However, there is no standardized curriculum for teaching and practicing musculoskeletal ultrasound during physical medicine and rehabilitation residency. The objective of this study was to describe a longitudinal curriculum using unembalmed fresh frozen cadavers to teach physical medicine and rehabilitation residents ultrasound-guided procedures. This protocol can help guide residents to begin learning how to independently identify important musculoskeletal structures and perform some of the most common musculoskeletal procedures relevant to clinical practice. Residents performed a procedure on average 6.99 times per block, and residents' self-reported confidence in various aspects of ultrasound practice significantly improved after this curriculum ( P < 0.005). Hence, a cadaver-based training curriculum may be a worthwhile tool for preparing physical medicine and rehabilitation residents to perform musculoskeletal ultrasound-guided procedures in the clinical setting.
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Affiliation(s)
- Theodora L Swenson
- From the Division of Physical Medicine and Rehabilitation, Vanderbilt University School of Medicine, Nashville, Tennessee (TLS, CR, SS); and University of Colorado School of Medicine, Aurora, Colorado (RTT)
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Tan X, Gerhard E, Wang Y, Tran RT, Xu H, Yan S, Rizk EB, Armstrong AD, Zhou Y, Du J, Bai X, Yang J. Development of Biodegradable Osteopromotive Citrate-Based Bone Putty. Small 2022; 18:e2203003. [PMID: 35717669 PMCID: PMC9463100 DOI: 10.1002/smll.202203003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Indexed: 05/30/2023]
Abstract
The burden of bone fractures demands development of effective biomaterial solutions, while additional acute events such as noncompressible bleeding further motivate the search for multi-functional implants to avoid complications including osseous hemorrhage, infection, and nonunion. Bone wax has been widely used in orthopedic bleeding control due to its simplicity of use and conformation to irregular defects; however, its nondegradability results in impaired bone healing, risk of infection, and significant inflammatory responses. Herein, a class of intrinsically fluorescent, osteopromotive citrate-based polymer/hydroxyapatite (HA) composites (BPLP-Ser/HA) as a highly malleable press-fit putty is designed. BPLP-Ser/HA putty displays mechanics replicating early nonmineralized bone (initial moduli from ≈2-500 kPa), hydration induced mechanical strengthening in physiological conditions, tunable degradation rates (over 2 months), low swelling ratios (<10%), clotting and hemostatic sealing potential (resistant to blood pressure for >24 h) and significant adhesion to bone (≈350-550 kPa). Simultaneously, citrate's bioactive properties result in antimicrobial (≈100% and 55% inhibition of S. aureus and E. coli) and osteopromotive effects. Finally, BPLP-Ser/HA putty demonstrates in vivo regeneration in a critical-sized rat calvaria model equivalent to gold standard autograft. BPLP-Ser/HA putty represents a simple, off-the-shelf solution to the combined challenges of acute wound management and subsequent bone regeneration.
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Affiliation(s)
- Xinyu Tan
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
- Academy of Orthopedics, Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong Province, 510280, China
| | - Ethan Gerhard
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yuqi Wang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Richard T. Tran
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Hui Xu
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Su Yan
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Elias B. Rizk
- Department of Neurosurgery, College of Medicine, The Pennsylvania State University, Hershey, PA 17033, USA
| | - April D. Armstrong
- Department of Orthopaedics and Rehabilitation, College of Medicine, The Pennsylvania State University, Hershey, PA 17033, USA
| | - Yuxiao Zhou
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jing Du
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, 510515, China
- Academy of Orthopedics, Provincial Key Laboratory of Bone and Joint Degenerative Diseases, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong Province, 510280, China
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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Swenson TL, Tran RT. What we learn by taking a social history. J Am Geriatr Soc 2022; 70:2710-2711. [DOI: 10.1111/jgs.17790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/12/2022] [Accepted: 03/27/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Theodora Lananh Swenson
- Department of Physical Medicine & Rehabilitation, Vanderbilt University Medical Center Nashville Tennessee USA
| | - Richard T. Tran
- University of Colorado School of Medicine Aurora Colorado USA
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Swenson TL, Tran RT. A fracture of the fifth metacarpal. Acad Emerg Med 2022; 29:518. [PMID: 34751989 DOI: 10.1111/acem.14413] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/02/2021] [Accepted: 11/06/2021] [Indexed: 11/30/2022]
Abstract
When the fifteen-year-old quarterback walks into the emergency department, he doesn't attract the same amount of attention compared to the moment when he had fumbled. His jersey is drenched in sweat and his cleats are covered in grass stains, but his vitals are perfectly normal. Not much about him is medically noteworthy except for his right hand, wrapped in an ACE bandage and slung across his chest. When the triage nurse gives the signal, his stepfather escorts him to the other side of the screen, past the families huddled around stretchers in the trauma bay and past the wails and cheers emanating from pod A. For some, Friday nights are spent on the field; for others, they are spent waiting in the emergency department.
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Affiliation(s)
- Theodora L. Swenson
- Department of Physical Medicine and Rehabilitation Vanderbilt University Medical Center Nashville Tennessee USA
| | - Richard T. Tran
- University of Colorado School of Medicine Aurora Colorado USA
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Tran RT, Rankin AJ, Abdul-Rahim AH, Lip GYH, Rankin AC, Lees KR. Short Runs of Atrial Arrhythmia and Stroke Risk: A European-Wide Online Survey among Stroke Physicians and Cardiologists. J R Coll Physicians Edinb 2016. [DOI: 10.1177/147827151604600205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- RT Tran
- Clinical Fellow in Acute Medicine, Queen Elizabeth University Hospital, Glasgow, UK
| | - AJ Rankin
- Medical Registrar, Acute Stroke Unit, Queen Elizabeth University Hospital, Glasgow, UK
| | - AH Abdul-Rahim
- Medical Registrar, Acute Stroke Unit, Queen Elizabeth University Hospital, Glasgow, UK
| | - GYH Lip
- Clinical Research Fellow in Stroke Medicine
| | - AC Rankin
- Consultant Cardiologist and Professor of Cardiovascular Medicine, University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Birmingham, UK
| | - KR Lees
- Professor of Cerebrovascular Medicine, Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK
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Tran RT, Rankin AJ, Abdul-Rahim AH, Lip GYH, Rankin AC, Lees KR. Short runs of atrial arrhythmia and stroke risk: a European-wide online survey among stroke physicians and cardiologists. J R Coll Physicians Edinb 2016; 46:87-92. [DOI: 10.4997/jrcpe.2016.204] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering.
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Affiliation(s)
- Richard T. Tran
- Department of Biomedical Engineering, Materials Research Institute, and The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, and The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Guillermo A. Ameer
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208
- Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208
- Simpson Querrey Institute for Bionanotechnology, Northwestern University, Chicago, Illinois 60611
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Xie D, Guo J, Mehdizadeh M, Tran RT, Chen R, Sun D, Qian G, Jin D, Bai X, Yang J. Development of Injectable Citrate-Based Bioadhesive Bone Implants. J Mater Chem B 2015; 3:387-398. [PMID: 25580247 PMCID: PMC4286886 DOI: 10.1039/c4tb01498g] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Injectable bone implants have been widely used in bone tissue repairs including the treatment of comminuted bone fractures (CBF). However, most injectable bone implants are not suitable for the treatment of CBF due to their weak tissue adhesion strengths and minimal osteoinduction. Citrate has been recently reported to promote bone formation through enhanced bioceramic integration and osteoinductivity. Herein, a novel injectable citrate-based mussel-inspired bioadhesive hydroxyapatite (iCMBA/HA) bone substitute was developed for CBF treatment. iCMBA/HA can be set within 2-4 minutes and the as-prepared (wet) iCMBA/HA possess low swelling ratios, compressive mechanical strengths of up to 3.2±0.27 MPa, complete degradation in 30 days, suitable biocompatibility, and osteoinductivity. This is also the first time to demonstrate that citrate supplementation in osteogenic medium and citrate released from iCMBA/HA degradation can promote the mineralization of osteoblastic committed human mesenchymal stem cells (hMSCs). In vivo evaluation of iCMBA/HA in a rabbit comminuted radial fracture model showed significantly increased bone formation with markedly enhanced three-point bending strength compared to the negative control. Neovascularization and bone ingrowth as well as highly organized bone formation were also observed showing the potential of iCMBA/HA in treating CBF.
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Affiliation(s)
- Denghui Xie
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China ; Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Jinshan Guo
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Mohammadreza Mehdizadeh
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Richard T Tran
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Ruisong Chen
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Dawei Sun
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Guoying Qian
- Department of Biology, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
| | - Dadi Jin
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Xiaochun Bai
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Jian Yang
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China ; Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
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Sun D, Chen Y, Tran RT, Xu S, Xie D, Jia C, Wang Y, Guo Y, Zhang Z, Guo J, Yang J, Jin D, Bai X. Citric acid-based hydroxyapatite composite scaffolds enhance calvarial regeneration. Sci Rep 2014; 4:6912. [PMID: 25372769 PMCID: PMC4220725 DOI: 10.1038/srep06912] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [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: 06/09/2014] [Accepted: 10/15/2014] [Indexed: 12/17/2022] Open
Abstract
Citric acid-based polymer/hydroxyapatite composites (CABP-HAs) are a novel class of biomimetic composites that have recently attracted significant attention in tissue engineering. The objective of this study was to compare the efficacy of using two different CABP-HAs, poly (1,8-octanediol citrate)-click-HA (POC-Click-HA) and crosslinked urethane-doped polyester-HA (CUPE-HA) as an alternative to autologous tissue grafts in the repair of skeletal defects. CABP-HA disc-shaped scaffolds (65 wt.-% HA with 70% porosity) were used as bare implants without the addition of growth factors or cells to renovate 4 mm diameter rat calvarial defects (n = 72, n = 18 per group). Defects were either left empty (negative control group), or treated with CUPE-HA scaffolds, POC-Click-HA scaffolds, or autologous bone grafts (AB group). Radiological and histological data showed a significant enhancement of osteogenesis in defects treated with CUPE-HA scaffolds when compared to POC-Click-HA scaffolds. Both, POC-Click-HA and CUPE-HA scaffolds, resulted in enhanced bone mineral density, trabecular thickness, and angiogenesis when compared to the control groups at 1, 3, and 6 months post-trauma. These results show the potential of CABP-HA bare implants as biocompatible, osteogenic, and off-shelf-available options in the repair of orthopedic defects.
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Affiliation(s)
- Dawei Sun
- 1] Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China [2] Department of Orthopaedics &Microsurgery, Guangdong No. 2 Provincial People's Hospital, Guangzhou, 510317, China
| | - Yuhui Chen
- Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China
| | - Richard T Tran
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, U.S.A
| | - Song Xu
- 1] Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China [2] State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China
| | - Denghui Xie
- 1] Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China [2] Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, U.S.A
| | - Chunhong Jia
- State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China
| | - Yuchen Wang
- Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China
| | - Ying Guo
- Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China
| | - Zhongmin Zhang
- Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China
| | - Jinshan Guo
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, U.S.A
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802, U.S.A
| | - Dadi Jin
- Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China
| | - Xiaochun Bai
- 1] Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510665, China [2] State Key Laboratory of Organ Failure Research, Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China
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Rankin AJ, Tran RT, Abdul-Rahim AH, Rankin AC, Lees KR. Clinically important atrial arrhythmia and stroke risk: a UK-wide online survey among stroke physicians and cardiologists. QJM 2014; 107:895-902. [PMID: 25174048 DOI: 10.1093/qjmed/hcu177] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A recording of ≥30 s is required for diagnosis of paroxysmal atrial fibrillation (AF) when using ambulatory electrocardiography (ECG) monitoring. It is unclear if shorter runs of atrial arrhythmia are relevant with regard to stroke risk. AIM To assess current management of patients with atrial arrhythmia of <30 s duration detected on ambulatory ECG. DESIGN Online survey. METHODS An online survey was sent to cardiologists and stroke physicians in the UK, via their national societies. RESULTS A total of 205 clinicians responded to the survey (130 stroke physicians, 64 cardiologists, 11 other). Regarding diagnosis of AF, 87% of responders would accept a single 12-lead ECG. In contrast, only 45% would accept a single episode lasting <30 s detected on ambulatory monitoring. There was more agreement with regard to the decision to anticoagulate. When asked whether they would anticoagulate eight hypothetical patients with non-diagnostic paroxysms of AF, there was a mean agreement of responses of 78.6%, with up to 94.1% agreement for high-risk patients. There was a trend suggesting that stroke physicians were more likely to accept an atrial arrhythmia of <30 s as 'AF' than cardiology specialists [OR 1.63 (95% CI 0.88-3.01), P = 0.12]. CONCLUSIONS There is a lack of consensus on the diagnosis and management of patients with brief runs of atrial arrhythmia detected on ambulatory ECG. Further research is needed to clarify the risk of stroke in this unique population of patients.
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Affiliation(s)
- A J Rankin
- From the Acute Stroke Unit, Western Infirmary Glasgow, G11 6NT, UK Institute of Cardiovascular and Medical Sciences, University of Glasgow, G12 8QQ, UK and School of Medicine, University of Glasgow, G12 8QQ, UK
| | - R T Tran
- From the Acute Stroke Unit, Western Infirmary Glasgow, G11 6NT, UK Institute of Cardiovascular and Medical Sciences, University of Glasgow, G12 8QQ, UK and School of Medicine, University of Glasgow, G12 8QQ, UK
| | - A H Abdul-Rahim
- From the Acute Stroke Unit, Western Infirmary Glasgow, G11 6NT, UK Institute of Cardiovascular and Medical Sciences, University of Glasgow, G12 8QQ, UK and School of Medicine, University of Glasgow, G12 8QQ, UK
| | - A C Rankin
- From the Acute Stroke Unit, Western Infirmary Glasgow, G11 6NT, UK Institute of Cardiovascular and Medical Sciences, University of Glasgow, G12 8QQ, UK and School of Medicine, University of Glasgow, G12 8QQ, UK
| | - K R Lees
- From the Acute Stroke Unit, Western Infirmary Glasgow, G11 6NT, UK Institute of Cardiovascular and Medical Sciences, University of Glasgow, G12 8QQ, UK and School of Medicine, University of Glasgow, G12 8QQ, UK
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Su LC, Xu H, Tran RT, Tsai YT, Tang L, Banerjee S, Yang J, Nguyen KT. In situ re-endothelialization via multifunctional nanoscaffolds. ACS Nano 2014; 8:10826-36. [PMID: 25222570 PMCID: PMC4212783 DOI: 10.1021/nn504636n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/11/2014] [Indexed: 05/25/2023]
Abstract
The endothelium monolayer lining in the luminal side of blood vessels provides critical antithrombotic functions. Damage to these cells will expose a highly thrombogenic subendothelium, which leads to pathological vascular changes. Using combined tissue engineering and ligand-receptor targeting strategy, we developed a biodegradable urethane-doped polyester (UPE) multifunctional targeting nanoparticle (MTN) scaffold system with dual ligands: (1) glycoprotein 1b (GP1b) to target the injured arterial endothelium and subendothelium and (2) anti-CD34 antibodies to capture endothelial progenitor cells for endothelium regeneration. The fabricated spherical MTNs of 400 nm were found to be cytocompatible and hemocompatible. Both the in vitro and ex vivo targeting of these nanoscaffolds not only showed binding specificity of MTNs onto the von Willebrand factor -coated surfaces that simulate the injured arterial walls but also competed with platelets for binding onto these injured sites. Further in vivo study has revealed that a single delivery of MTNs upon vascular injury reduced neointimal hyperplasia by 57% while increased endothelium regeneration by ∼ 60% in 21 days. These results support the promise of using MTN nanoscaffolds for treating vascular injury in situ.
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Affiliation(s)
- Lee-Chun Su
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
| | - Hao Xu
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, United States
| | - Richard T. Tran
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yi-Ting Tsai
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
| | - Liping Tang
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
| | - Subhash Banerjee
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, United States
| | - Jian Yang
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kytai T. Nguyen
- Department of Bioengineering, University of Texas at Arlington, Arlington, Texas 76010, United States
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Guo Y, Tran RT, Xie D, Wang Y, Nguyen DY, Gerhard E, Guo J, Tang J, Zhang Z, Bai X, Yang J. Citrate-based biphasic scaffolds for the repair of large segmental bone defects. J Biomed Mater Res A 2014; 103:772-81. [PMID: 24829094 DOI: 10.1002/jbm.a.35228] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [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: 03/15/2014] [Revised: 05/05/2014] [Accepted: 05/13/2014] [Indexed: 12/29/2022]
Abstract
Attempts to replicate native tissue architecture have led to the design of biomimetic scaffolds focused on improving functionality. In this study, biomimetic citrate-based poly (octanediol citrate)-click-hydroxyapatite (POC-Click-HA) scaffolds were developed to simultaneously replicate the compositional and architectural properties of native bone tissue while providing immediate structural support for large segmental defects following implantation. Biphasic scaffolds were fabricated with 70% internal phase porosity and various external phase porosities (between 5 and 50%) to mimic the bimodal distribution of cancellous and cortical bone, respectively. Biphasic POC-Click-HA scaffolds displayed compressive strengths up to 37.45 ± 3.83 MPa, which could be controlled through the external phase porosity. The biphasic scaffolds were also evaluated in vivo for the repair of 10-mm long segmental radial defects in rabbits and compared to scaffolds of uniform porosity as well as autologous bone grafts after 5, 10, and 15 weeks of implantation. The results showed that all POC-Click-HA scaffolds exhibited good biocompatibility and extensive osteointegration with host bone tissue. Biphasic scaffolds significantly enhanced new bone formation with higher bone densities in the initial stages after implantation. Biomechanical and histomorphometric analysis supported a similar outcome with biphasic scaffolds providing increased compression strength, interfacial bone ingrowth, and periosteal remodeling in early time points, but were comparable to all experimental groups after 15 weeks. These results confirm the ability of biphasic scaffold architectures to restore bone tissue and physiological functions in the early stages of recovery, and the potential of citrate-based biomaterials in orthopedic applications.
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Affiliation(s)
- Ying Guo
- Department of Orthopedic, Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510280, China; Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China
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15
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Guo J, Xie Z, Tran RT, Xie D, Yang J. Click chemistry plays a dual role in biodegradable polymer design. Adv Mater 2014; 26:1906-11. [PMID: 24375469 PMCID: PMC3969723 DOI: 10.1002/adma.201305162] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/15/2013] [Indexed: 05/03/2023]
Abstract
Click chemistry plays a dual role in the design of new citrate-based biodegradable elastomers (CABEs) with greatly improved mechanical strength and easily clickable surfaces for biofunctionalization. This novel chemistry modification strategy is applicable to a number of different types of polymers for improved mechanical properties and biofunctionality.
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Affiliation(s)
- Jinshan Guo
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Zhiwei Xie
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Richard T. Tran
- Department of Biomedical Engineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Denghui Xie
- Academy of Orthopedics of Guangdong Province, Guangzhou, 510630, China, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510630, China, Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jian Yang
- Corresponding author: Jian Yang, W340 Millennium Science Complex, University Park, PA 16802. Tel.: (+1) 814-865-1278;
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16
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Gyawali D, Zhou S, Tran RT, Zhang Y, Liu C, Bai X, Yang J. Fluorescence imaging enabled biodegradable photostable polymeric micelles. Adv Healthc Mater 2014; 3:182-6. [PMID: 23983129 PMCID: PMC3844036 DOI: 10.1002/adhm.201300145] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 05/14/2013] [Indexed: 11/06/2022]
Abstract
Amphiphilic biodegradable photoluminescent polymers (ABPLPs) composed of a biodegradable fluorescent polymer and methoxy poly (ethyleneglycol) demonstrate intrinsic bright, tunable, and stable fluorescence emission. ABPLP micelles elicit minor cellular toxicity and can be used for cell and tissue imaging both in vitro and in vivo.
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Affiliation(s)
- Dipendra Gyawali
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010
| | - Shengyuan Zhou
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010
| | - Richard T. Tran
- Department of Bioengineering, Materials Research Institute, Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Yi Zhang
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010
| | - Chao Liu
- Department of Bioengineering, Materials Research Institute, Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Xiaochun Bai
- Academy of Orthopedics of Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou 510280, China
| | - Jian Yang
- Department of Bioengineering, Materials Research Institute, Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, PA 16802
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17
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Tran RT, Choy WM, Cao H, Qattan I, Chiao JC, Ip WY, Yeung KWK, Yang J. Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester tissue engineered nerve guides. J Biomed Mater Res A 2013; 102:2793-804. [PMID: 24115502 DOI: 10.1002/jbm.a.34952] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [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: 06/13/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 01/06/2023]
Abstract
Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering.
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Affiliation(s)
- Richard T Tran
- Department of Bioengineering, Materials Research Institute, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802
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18
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Tran RT, Wang L, Zhang C, Huang M, Tang W, Zhang C, Zhang Z, Jin D, Banik B, Brown JL, Xie Z, Bai X, Yang J. Synthesis and characterization of biomimetic citrate-based biodegradable composites. J Biomed Mater Res A 2013; 102:2521-32. [PMID: 23996976 DOI: 10.1002/jbm.a.34928] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [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: 07/14/2013] [Revised: 08/07/2013] [Accepted: 08/12/2013] [Indexed: 12/27/2022]
Abstract
Natural bone apatite crystals, which mediate the development and regulate the load-bearing function of bone, have recently been associated with strongly bound citrate molecules. However, such understanding has not been translated into bone biomaterial design and osteoblast cell culture. In this work, we have developed a new class of biodegradable, mechanically strong, and biocompatible citrate-based polymer blends (CBPBs), which offer enhanced hydroxyapatite binding to produce more biomimetic composites (CBPBHAs) for orthopedic applications. CBPBHAs consist of the newly developed osteoconductive citrate-presenting biodegradable polymers, crosslinked urethane-doped polyester and poly (octanediol citrate), which can be composited with up to 65 wt % hydroxyapatite. CBPBHA networks produced materials with a compressive strength of 116.23 ± 5.37 MPa comparable to human cortical bone (100-230 MPa), and increased C2C12 osterix gene and alkaline phosphatase gene expression in vitro. The promising results above prompted an investigation on the role of citrate supplementation in culture medium for osteoblast culture, which showed that exogenous citrate supplemented into media accelerated the in vitro phenotype progression of MG-63 osteoblasts. After 6 weeks of implantation in a rabbit lateral femoral condyle defect model, CBPBHA composites elicited minimal fibrous tissue encapsulation and were well integrated with the surrounding bone tissues. The development of citrate-presenting CBPBHA biomaterials and preliminary studies revealing the effects of free exogenous citrate on osteoblast culture shows the potential of citrate biomaterials to bridge the gap in orthopedic biomaterial design and osteoblast cell culture in that the role of citrate molecules has previously been overlooked.
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Affiliation(s)
- Richard T Tran
- Department of Bioengineering, Materials Research Institute, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, 16802
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19
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Su LC, Xu H, Tran RT, Tsai YT, Tang L, Yang JI, Nguyen KT. Abstract 291: In Situ Re-endothelialization via Multifunctional Nanoscaffolds. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The endothelium monolayer lining in the luminal side of blood vessels provides critical anti-thrombotic activities. Damage to these cells will expose a highly thrombogenic subendothelium that stimulates thrombosis. Standing on the concept of tissue engineering and ligand-receptor targeting strategy, we developed a novel biodegradable urethane-doped polyester (UPE) multifunctional targeting nanoparticle (MTN) scaffold system with dual ligands: 1) GP1b-α to target the injured arterial endothelium and subendothelium and 2) anti-CD34 antibodies to capture endothelial progenitor cells (EPCs) for endothelium regeneration. The fabricated spherical MTNs of 400 nm were shown to be biocompatible and hemocompatible. Both the
in vitro
and
ex vivo
targeting of these nanoscaffolds not only showed improved binding efficiency of MTNs onto the von Willebrand Factor (vWF) coated surfaces presented as the injured arterial walls, but also outperformed platelets for binding onto these injured sites. Our
in vivo
study further showed 57% neointimal hyperplasia suppression and a 70% increase in endothelium regeneration within 21 days after delivering of MTNs upon vascular injury. These results indicate that our injectable MTN nanoscaffolds show a potential non-invasive way for endothelium regeneration
in situ
.
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Affiliation(s)
- Lee-Chun Su
- Bioengineering, The Univ of Texas at Arlington, Arlington, TX
| | - Hao Xu
- Cardiology, The Univ of Texas Southwestern Med Cntr at Dallas, Dallas, TX
| | - Richard T Tran
- Bioengineering, The Pennsylvania State Univesity, Univ Park, PA
| | - Yi-Ting Tsai
- Bioengineering, The Univ of Texas at Arlington, Arlington, TX
| | - Liping Tang
- Bioengineering, The Univ of Texas at Arlington, Arlington, TX
| | - JIan Yang
- Bioengineering, The Pennsylvania State Univ, Univ Park, PA
| | - Kytai T Nguyen
- Bioengineering, The Univ of Texas at Arlington, Arlington, TX
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20
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Abstract
Recently, magnetic-based theranostic nanoparticle (MBTN) systems have been studied, researched, and applied extensively to detect and treat various diseases including cancer. Theranostic nanoparticles are advantageous in that the diagnosis and treatment of a disease can be performed in a single setting using combinational strategies of targeting, imaging, and/or therapy. Of these theranostic strategies, magnetic-based systems containing magnetic nanoparticles (MNPs) have gained popularity because of their unique ability to be used in magnetic resonance imaging, magnetic targeting, hyperthermia, and controlled drug release. To increase their effectiveness, MNPs have been decorated with a wide variety of materials to improve their biocompatibility, carry therapeutic payloads, encapsulate/bind imaging agents, and provide functional groups for conjugation of biomolecules that provide receptor-mediated targeting of the disease. This review summarizes recent patents involving various polymer coatings, imaging agents, therapeutic agents, targeting mechanisms, and applications along with the major requirements and challenges faced in using MBTN for disease management.
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Affiliation(s)
- Aniket S Wadajkar
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019 ; Joint Biomedical Engineering Program between The University of Texas at Arlington and The University of Texas Southwestern Medical Center, Dallas, TX 75390
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21
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Jiao Y, Gyawali D, Stark JM, Akcora P, Nair P, Tran RT, Yang J. A Rheological Study of Biodegradable Injectable PEGMC/HA Composite Scaffolds. Soft Matter 2012; 8:1499-1507. [PMID: 25309615 PMCID: PMC4193808 DOI: 10.1039/c1sm05786c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Injectable biodegradable hydrogels, which can be delivered in a minimally invasive manner and formed in situ, have found a number of applications in pharmaceutical and biomedical applications, such as drug delivery and tissue engineering. We have recently developed an in situ crosslinkable citric acid-based biodegradable poly (ethylene glycol) maleate citrate (PEGMC)/hydroxyapatite (HA) composite, which shows promise for use in bone tissue engineering. In this study, the mechanical properties of the PEGMC/HA composites were studied in dynamic linear rheology experiments. Critical parameters such as monomer ratio, crosslinker, initiator, and HA concentrations were varied to reveal their effect on the extent of crosslinking as they control the mechanical properties of the resultant gels. The rheological studies, for the first time, allowed us investigating the physical interactions between HA and citric acid-based PEGMC. Understanding the viscoelastic properties of the injectable gel composites is crucial in formulating suitable injectable PEGMC/HA scaffolds for bone tissue engineering, and should also promote the other biomedical applications based on citric acid-based biodegradable polymers.
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Affiliation(s)
- Yang Jiao
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Dipendra Gyawali
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010, USA
- Joint Biomedical Engineering Program, The University of Texas Southwestern Medical Center and The University of Texas at Arlington, Dallas, TX 75390, USA
| | - Joseph M. Stark
- Department of Chemical Engineering, University of Missouri, Columbia, MO 65211, USA
| | - Pinar Akcora
- Department of Chemical Engineering & Materials Science, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Parvathi Nair
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010, USA
- Joint Biomedical Engineering Program, The University of Texas Southwestern Medical Center and The University of Texas at Arlington, Dallas, TX 75390, USA
| | - Richard T. Tran
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010, USA
- Joint Biomedical Engineering Program, The University of Texas Southwestern Medical Center and The University of Texas at Arlington, Dallas, TX 75390, USA
| | - Jian Yang
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76010, USA
- Joint Biomedical Engineering Program, The University of Texas Southwestern Medical Center and The University of Texas at Arlington, Dallas, TX 75390, USA
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22
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Dey J, Tran RT, Shen J, Tang L, Yang J. Development and long-term in vivo evaluation of a biodegradable urethane-doped polyester elastomer. Macromol Mater Eng 2011; 296:1149-1157. [PMID: 22184499 PMCID: PMC3241003 DOI: 10.1002/mame.201100074] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have recently reported upon the development of crosslinked urethane-doped polyester (CUPE) network elastomers, which was motivated by the desire to overcome the drawbacks presented by crosslinked network polyesters and biodegradable polyurethanes for soft tissue engineering applications. Although the effect of the isocyanate content and post-polymerization conditions on the material structure-property relationship was examined in detail, the ability of the diol component to modulate the material properties was only studied briefly. Herein, we present a detailed report on the development of CUPE polymers synthesized using diols 4, 6, 8, 10, or 12 methylene units in length in order to investigate what role the diol component plays on the resulting material's physical properties, and assess their long-term biological performance in vivo. An increase in the diol length was shown to affect the physical properties of the CUPE polymers primarily through lowered polymeric crosslinking densities and elevated material hydrophobicity. The use of longer chain diols resulted in CUPE polymers with increased molecular weights resulting in higher tensile strength and elasticity, while also increasing the material hydrophobicity to lower bulk swelling and prolong the polymer degradation rates. Although the number of methylene units largely affected the physical properties of CUPE, the choice of diol did not affect the overall polymer cell/tissue-compatibility both in vitro and in vivo. In conclusion, we have established the diol component as an important parameter in controlling the structure-property relationship of the polymer in addition to diisocyanate concentration and post-polymerization conditions. Expanding the family of CUPE polymers increases the choices of biodegradable elastomers for tissue engineering applications.
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23
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Tran RT, Naseri E, Kolasnikov A, Bai X, Yang J. A new generation of sodium chloride porogen for tissue engineering. Biotechnol Appl Biochem 2011; 58:335-44. [DOI: 10.1002/bab.44] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 07/13/2011] [Indexed: 01/01/2023]
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24
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Tran RT, Gyawali D, Nair P, Yang J. Chapter 14. Biodegradable Injectable Systems for Bone Tissue Engineering. Green Chemistry Series 2011. [DOI: 10.1039/9781849733458-00419] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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25
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Zhang Y, Tran RT, Gyawali D, Yang J. Development of Photocrosslinkable Urethane-Doped Polyester Elastomers for Soft Tissue Engineering. Int J Biomater Res Eng 2011; 1:18-31. [PMID: 23565318 PMCID: PMC3615254 DOI: 10.4018/ijbre.2011010102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Finding an ideal biomaterial with the proper mechanical properties and biocompatibility has been of intense focus in the field of soft tissue engineering. This paper reports on the synthesis and characterization of a novel crosslinked urethane-doped polyester elastomer (CUPOMC), which was synthesized by reacting a previously developed photocrosslinkable poly (octamethylene maleate citrate) (POMC) prepolymers (pre-POMC) with 1,6-hexamethylene diisocyanate (HDI) followed by thermo- or photo-crosslinking polymerization. The mechanical properties of the CUPOMCs can be tuned by controlling the molar ratios of pre-POMC monomers, and the ratio between the prepolymer and HDI. CUPOMCs can be crosslinked into a 3D network through polycondensation or free radical polymerization reactions. The tensile strength and elongation at break of CUPOMC synthesized under the known conditions range from 0.73±0.12MPa to 10.91±0.64MPa and from 72.91±9.09% to 300.41±21.99% respectively. Preliminary biocompatibility tests demonstrated that CUPOMCs support cell adhesion and proliferation. Unlike the pre-polymers of other crosslinked elastomers, CUPOMC pre-polymers possess great processability demonstrated by scaffold fabrication via a thermally induced phase separation method. The dual crosslinking methods for CUPOMC pre-polymers should enhance the versatile processability of the CUPOMC used in various conditions. Development of CUPOMC should expand the choices of available biodegradable elastomers for various biomedical applications such as soft tissue engineering.
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Affiliation(s)
- Yi Zhang
- University of Texas at Arlington, USA
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26
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Abstract
Citric-acid-derived thermally cross-linked biodegradable elastomers (CABEs) have recently received significant attention in various biomedical applications, including tissue-engineering orthopedic devices, bioimaging and implant coatings. However, citric-acid-derived photo-cross-linked biodegradable elastomers are rarely reported. Herein, we report a novel photo-cross-linked biodegradable elastomer, referred to as poly(octamethylene maleate citrate) (POMC), which preserves pendant hydroxyl and carboxylic functionalities after cross-linking for the potential conjugation of biologically active molecules. Pre-POMC is a low-molecular-mass pre-polymer with an average molecular mass between 701 and 1291 Da. POMC networks are soft and elastic with an initial modulus of 0.07 to 1.3 MPa and an elongation-at-break between 38 and 382%. FT-IR-ATR results confirmed the successful surface immobilization of type-I collagen onto POMC films, which enhanced in vitro cellular attachment and proliferation. Photo-polymerized POMC films implanted subcutaneously into Sprague-Dawley rats demonstrated minimal in vivo inflammatory responses. The development of POMC enriches the family of citric-acid-derived biodegradable elastomers and expands the available biodegradable polymers for versatile needs in biomedical applications.
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Affiliation(s)
- Dipendra Gyawali
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA
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27
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Abstract
Creating heterogeneous tissue constructs with an even cell distribution and robust mechanical strength remain important challenges to the success of in vivo tissue engineering. To address these issues, we are developing a scaffold sheet tissue engineering strategy consisting of thin (∼200 μm), strong, elastic, and porous crosslinked urethane-doped polyester (CUPE) scaffold sheets that are bonded together chemically or through cell culture. Suture retention of the tissue constructs (four sheets) fabricated by the scaffold sheet tissue engineering strategy is close to the surgical requirement (1.8 N) rendering their potential for immediate implantation without a need for long cell culture times. Cell culture results using 3T3 fibroblasts show that the scaffold sheets are bonded into a tissue construct via the extracellular matrix produced by the cells after 2 weeks of in vitro cell culture.
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Affiliation(s)
| | | | | | | | | | - Jian Yang
- Author to whom correspondence should be addressed: E-Mail: (J.Y.); Tel.: 817-272-0562; Fax: 817-272-2251
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28
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Tran RT, Thevenot P, Gyawali D, Chiao JC, Tang L, Yang J. Synthesis and characterization of a biodegradable elastomer featuring a dual crosslinking mechanism. Soft Matter 2010; 6:2449-2461. [PMID: 22162975 PMCID: PMC3233194 DOI: 10.1039/c001605e] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The need for advanced materials in emerging technologies such as tissue engineering has prompted increased research to produce novel biodegradable polymers elastic in nature and mechanically compliant with the host tissue. We have developed a soft biodegradable elastomeric platform biomaterial created from citric acid, maleic anhydride, and 1,8-octanediol, poly(octamethylene maleate (anhydride) citrate) (POMaC), which is able to closely mimic the mechanical properties of a wide range of soft biological tissues. POMaC features a dual crosslinking mechanism, which allows for the option of the crosslinking POMaC using UV irradiation and/or polycondensation to fit the needs of the intended application. The material properties, degradation profiles, and functionalities of POMaC thermoset networks can all be tuned through the monomer ratios and the dual crosslinking mechanism. POMaC polymers displayed an initial modulus between 0.03 and 1.54 MPa, and elongation at break between 48% and 534% strain. In vitro and in vivo evaluation using cell culture and subcutaneous implantation, respectively, confirmed cell and tissue biocompatibility. POMaC biodegradable polymers can also be combined with MEMS technology to fabricate soft and elastic 3D microchanneled scaffolds for tissue engineering applications. The introduction of POMaC will expand the choices of available biodegradable polymeric elastomers. The dual crosslinking mechanism for biodegradable elastomer design should contribute to biomaterials science.
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Affiliation(s)
- Richard T. Tran
- Department of Bioengineering, The University of Texas, Arlington, TX, 76019, USA; Fax: +817-272-2251; Tel: +817-272-0561
| | - Paul Thevenot
- Department of Bioengineering, The University of Texas, Arlington, TX, 76019, USA; Fax: +817-272-2251; Tel: +817-272-0561
| | - Dipendra Gyawali
- Department of Bioengineering, The University of Texas, Arlington, TX, 76019, USA; Fax: +817-272-2251; Tel: +817-272-0561
| | - Jung-Chih Chiao
- Department of Electrical Engineering, The University of Texas, Arlington, TX, 76019, USA
| | - Liping Tang
- Department of Bioengineering, The University of Texas, Arlington, TX, 76019, USA; Fax: +817-272-2251; Tel: +817-272-0561
| | - Jian Yang
- Department of Bioengineering, The University of Texas, Arlington, TX, 76019, USA; Fax: +817-272-2251; Tel: +817-272-0561
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