1
|
Boodagh P, Johnson R, Maly C, Ding Y, Tan W. Soft-sheath, stiff-core microfiber hydrogel for coating vascular implants. Colloids Surf B Biointerfaces 2019; 183:110395. [PMID: 31386934 DOI: 10.1016/j.colsurfb.2019.110395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/17/2019] [Accepted: 07/23/2019] [Indexed: 12/27/2022]
Abstract
Vascular implants remain clinically challenged due to often-occurring thrombosis and stenosis. Critical to addressing these complications is the design of implant material surfaces to inhibit the activities of platelets, smooth muscle cells (SMCs) and inflammatory cells. Recent mechanobiology studies accentuate the significance of material elasticity to cells and tissues. We thus developed and characterized an implant coating composed of hybrid, viscoelastic microfibers with coaxial core-sheath nanostructure. The coating over metallic stent material was formed by first depositing coaxially-electrospun fibers of poly(L-lactic acid) core and polyethylene glycol dimethacrylate sheath, and then polymerizing fibers with various UV times. Material characterizations were performed to evaluate the coating structure, mechanical property and biocompatibility. Results showed that coaxial microfibers exhibited arterial-like mechanics. The soft surface, high water content and swelling ratio of the coaxial fibers resemble hydrogels, while they are mechanically strong with an elastic modulus of 172-729 kPa. The coating strength and surface elasticity were tunable with the photopolymerization time. Further, the elastic fibers, as conformal coating on stent metal, strongly reduced SMC overgrowth and discouraged platelet adhesion and activation, compared to bare metals. Importantly, after 7-day subcutaneous implantation, coaxial fiber-coated implants showed more favorable in vivo responses with reduced tissue encapsulation, compared to bare stent metals or those coated with a two-layered fiber mixture composed of fibers from individual polymers. The excellent biocompatibility aroused from nanostructural interfaces of hybrid fibers offering hydrated, soft, nonfouling microenvironments. Such integrated fiber system may allow creation of advanced vascular implants that possess physico-mechanical properties of native arteries.
Collapse
Affiliation(s)
- P Boodagh
- Department of Mechanical Engineering, University of Colorado at Boulder, CO, USA; Section of Cardiovascular Medicine and Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, CT, USA; Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA.
| | - R Johnson
- Department of Mechanical Engineering, University of Colorado at Boulder, CO, USA
| | - C Maly
- Department of Mechanical Engineering, University of Colorado at Boulder, CO, USA
| | - Y Ding
- Department of Mechanical Engineering, University of Colorado at Boulder, CO, USA
| | - W Tan
- Department of Mechanical Engineering, University of Colorado at Boulder, CO, USA
| |
Collapse
|
2
|
Peng J, Rochow N, Dabaghi M, Bozanovic R, Jansen J, Predescu D, DeFrance B, Lee SY, Fusch G, Ravi Selvaganapathy P, Fusch C. Postnatal dilatation of umbilical cord vessels and its impact on wall integrity: Prerequisite for the artificial placenta. Int J Artif Organs 2018; 41:393-399. [PMID: 29562805 DOI: 10.1177/0391398818763663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION A lung assist device, which acts as an artificial placenta, can provide additional gas exchange for preterm and term newborns with respiratory failure. The concept of the lung assist device requires a large bore access via umbilical vessels to allow pumpless extracorporeal blood flow rates up to 30 mL/kg/min. After birth, constricted umbilical vessels need to be reopened for vascular access. The objective is to study the impact of umbilical vessel expansion on vessel integrity for achieving large bore access. METHODS Umbilical cords from healthy term deliveries were cannulated and dilatated with percutaneous transluminal angioplasty catheters in 1 mm increments from 4 to 8 mm for umbilical artery and from 4 to 15 mm for umbilical vein, n = 6 per expansion diameter. Paraffin-embedded transverse sections of dilated and control samples were HE & Van Gieson stained. Effects of dilatation, shown by splitting, were measured. RESULTS Umbilical vessel expansion led to concentric splitting, shown by areas devoid of extracellular matrix and nuclei in the tunica intima and media. No radial splitting was observed. Results suggest an expansion threshold of umbilical artery at 6 mm and umbilical vein at 7 mm, while maximal splitting was observed above this threshold (3.6 ± 0.8%, p = 0.043 for umbilical artery 7 mm and 6.3 ± 1.8%, p = 0.048 for umbilical vein 8 mm). Endothelial cell sloughing was present in all dilated samples but not in the control samples. CONCLUSION The suggested thresholds for safe expansions are similar to in utero umbilical vessel diameters and demonstrate a proof of concept for attaining large bore access for the lung assist device.
Collapse
Affiliation(s)
- Jenny Peng
- 1 Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada.,2 Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Niels Rochow
- 1 Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | | | - Radenka Bozanovic
- 4 Department of Pathology and Molecular Medicine, Pediatric Pathology, McMaster University, Hamilton, ON, Canada
| | - Jan Jansen
- 4 Department of Pathology and Molecular Medicine, Pediatric Pathology, McMaster University, Hamilton, ON, Canada
| | - Dragos Predescu
- 5 Division of Cardiology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Bryon DeFrance
- 6 Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, McMaster University, Hamilton, ON, Canada
| | - Sau-Young Lee
- 1 Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Gerhard Fusch
- 1 Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Ponnambalam Ravi Selvaganapathy
- 3 Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada.,7 School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada
| | - Christoph Fusch
- 1 Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada.,8 Department of Pediatrics, Paracelsus Medical School, General Hospital of Nuremberg, Nuremberg, Germany
| |
Collapse
|
3
|
Danon S, Gray RG, Crystal MA, Morgan G, Gruenstein DH, Goldstein BH, Gordon BM. Expansion Characteristics of Stents Used in Congenital Heart Disease: Serial Dilation Offers Improved Expansion Potential Compared to Direct Dilation: Results from a Pediatric Interventional Cardiology Early Career Society (PICES) Investigation. CONGENIT HEART DIS 2016; 11:741-750. [DOI: 10.1111/chd.12399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Saar Danon
- Division of Pediatric Cardiology; Saint Louis University; St. Louis Mo USA
| | - Robert G. Gray
- Division of Pediatric Cardiology; University of Utah; Salt Lake City Utah USA
| | - Matthew A. Crystal
- Division of Pediatric Cardiology; Columbia University Medical Center; New York NY USA
| | - Gareth Morgan
- Division of Pediatric Cardiology; Guy's and St Thomas' Hospital; London United Kingdom
| | | | - Bryan H. Goldstein
- The Heart Institute, Cincinnati Children's Hospital Medical Center; Cincinnati Ohio USA
| | - Brent M. Gordon
- Division of Pediatric Cardiology; Loma Linda University Children's Hospital; Loma Linda Calif USA
| |
Collapse
|
4
|
Farhatnia Y, Tan A, Motiwala A, Cousins BG, Seifalian AM. Evolution of covered stents in the contemporary era: clinical application, materials and manufacturing strategies using nanotechnology. Biotechnol Adv 2013; 31:524-42. [DOI: 10.1016/j.biotechadv.2012.12.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/20/2012] [Accepted: 12/30/2012] [Indexed: 12/24/2022]
|
5
|
Bruckheimer E, Birk E, Santiago R, Dagan T, Esteves C, Pedra CAC. Coarctation of the aorta treated with the Advanta V12 large diameter stent: acute results. Catheter Cardiovasc Interv 2010; 75:402-6. [PMID: 19885914 DOI: 10.1002/ccd.22280] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To report on the early results of treatment of coarctation of the aorta by dilation with a new polytetrafluoroethylene covered stent. BACKGROUND Transcatheter dilation of aortic coarctation carries the risk of aneurysm or rupture. Covered stent implantation reduces this risk but requires a large delivery system. The Advanta V12 LD covered stent is premounted and requires a 9-11 Fr delivery system. METHODS Covered stents on balloons of a diameter sufficient to anchor the stent in the coarctation were implanted using the smallest available delivery system. Secondary dilation with larger diameter balloons was performed until the pressure gradient was <20 mm Hg and the stent was opposed to the aortic wall. RESULTS Twenty-five patients with aortic coarctation underwent stent implantation. Coarctation diameter increased from (6.3 + or - 3.5) mm to (14.4 + or - 2.3) mm (P < 0.0001). Peak pressure gradient decreased from (25.3 + or - 11.6) mm Hg to (2.5 + or - 3.0) mm Hg (P < 0.0001). The stent achieved the desired diameter in all cases. There were no complications. At short-term median follow-up of 4.9 months, all patients are alive and well with no evidence of recoarctation or aneurysm. CONCLUSIONS These initial results show that the covered Advanta V12LD stent is safe and effective in the immediate treatment of coarctation of the aorta through a low profile delivery system of 8-11 Fr. Long term follow up is required.
Collapse
Affiliation(s)
- Elchanan Bruckheimer
- Pediatric Cardiac Catheterization, Schneider Children's Medical Center Israel, Kaplan 14, Petach Tikva, Israel.
| | | | | | | | | | | |
Collapse
|