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Poss pcu

Camilo Chaves, Feras Alshomer, Robert G Palgrave, Deepak M Kalaskar
This study present amino functionalization of biocompatible polymer polyhedral oligomeric silsequioxane-poly(carbonate-urea) urethane (POSS-PCU) using plasma polymerization process to induce osteogenic differentiation of adipose derived stem cells (ADSCs). Optimization of plasma polymerization process was carried out keeping cell culture application in mind. Thus, samples were rigorously tested for retention of amino groups under both dry and wet conditions. Physio-chemical characterization was carried out using ninhydrin test, X-ray photon spectroscopy, scanning electron microscopy, and static water contact analysis...
July 27, 2016: ACS Applied Materials & Interfaces
Michelle Griffin, Leila Nayyer, Peter E Butler, Robert G Palgrave, Alexander M Seifalian, Deepak M Kalaskar
We demonstrate an efficient method to produce mechano-responsive polymeric scaffolds which can alter cellular functions using two different functionalized (OH and NH2) silica nano-fillers. Fumed silica-hydroxyl and fumed silica-amine nano-fillers were mixed with a biocompatible polymer (POSS-PCU) at various wt% to produce scaffolds. XPS and mechanical testing demonstrate that bulk mechanical properties are modified without changing the scaffold's surface chemistry. Mechanical testing showed significant change in bulk properties of POSS-PCU scaffolds with an addition of silica nanofillers as low as 1% (P<0...
August 2016: Nanomedicine: Nanotechnology, Biology, and Medicine
Leila Nayyer, Gavin Jell, Ali Esmaeili, Martin Birchall, Alexander M Seifalian
Current biomaterials for auricular replacement are associated with high rates of infection and extrusion. The development of new auricular biomaterials that mimic the mechanical properties of native tissue and promote desirable cellular interactions may prevent implant failure. A porous 3D nanocomposite scaffold (NS) based on POSS-PCU (polyhedral oligomeric silsesquioxane nanocage into polycarbonate based urea-urethane) is developed with an elastic modulus similar to native ear. In vitro biological interactions on this NS reveal greater protein adsorption, increased fibroblast adhesion, proliferation, and collagen production compared with Medpor (the current synthetic auricular implant)...
May 2016: Advanced Healthcare Materials
Claire Crowley, Poramate Klanrit, Colin R Butler, Aikaterini Varanou, Manuela Platé, Robert E Hynds, Rachel C Chambers, Alexander M Seifalian, Martin A Birchall, Sam M Janes
Polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) is a versatile nanocomposite biomaterial with growing applications as a bioscaffold for tissue engineering. Integration of synthetic implants with host tissue can be problematic but could be improved by topographical modifications. We describe optimization of POSS-PCU by dispersion of porogens (sodium bicarbonate (NaHCO3), sodium chloride (NaCl) and sucrose) onto the material surface, with the principle aim of increasing surface porosity, thus providing additional opportunities for improved cellular and vascular ingrowth...
March 2016: Biomaterials
Hossein Ghanbari, Dina Radenkovic, Sayed Mahdi Marashi, Shirin Parsno, Nima Roohpour, Gaetano Burriesci, Alexander M Seifalian
In the cardiovascular system, the endothelial layer provides a natural antithrombogenic surface on the inner portion of the heart and associated vessels. For a synthetic material therefore, the ability to attract and retain endothelial or endothelial progenitor cells (EPCs), ultimately creating a single endothelial layer on its surface, is of prime importance. The authors have developed a nanocomposite polymer, based on a combination of polyhedral oligomeric silsesquioxane nanoparticles and polycarbonate urea urethane (POSS-PCU), which is biocompatible and has been used in human for the world's first synthetic trachea, tear duct, and bypass graft...
June 2016: Biointerphases
Michelle F Griffin, Robert G Palgrave, Alexander M Seifalian, Peter E Butler, Deepak M Kalaskar
Current surgical reconstruction of facial defects including nose or ear involves harvesting patient's own autologous tissue, causing donor site morbidity and is limited by tissue availability. The use of alternative synthetic materials is also limited due to complications related to poor tissue integration and angiogenesis, which lead to extrusion of implants and infection. We intend to meet this clinical challenge by using a novel nanocomposite called polyhedral oligomeric silsesquioxane poly(carbonate-urea)urethane (POSS-PCU), which has already been successfully taken to the clinical bench-side as a replacement for trachea, tear duct and vascular by-pass graft...
January 2016: Biomaterials Science
Sarwat B Rizvi, Shi Yu Yang, Mark Green, Mo Keshtgar, Alexander M Seifalian
Quantum dots (QDs) are fluorescent nanoparticles with unique photophysical properties that enable them to potentially replace traditional organic dyes and fluorescent proteins in various bioimaging applications. However, the inherent toxicity of their cores based on cadmium salts limits their widespread biomedical use. We have developed a novel nanocomposite polymer emulsion based on polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) that can be used to coat quantum dots to nullify their toxicity and enhance photostability...
December 16, 2015: Bioconjugate Chemistry
Junjie Zhao, Yasmin Farhatnia, Deepak M Kalaskar, Yanting Zhang, Peter E M Bulter, Alexander M Seifalian
BACKGROUND: The physio-chemical properties of blood contacting biomaterials play an important role in determining their hemocompatibility. It is shown in literature that surface roughness and porosity have significant effect on hemocompatibility. In this study, we use a biocompatible, low thrombogenic nanocomposite polymer called POSS-PCU to test this hypothesis: would porosity compromise the hemocompatibility of POSS-PCU. We compared the hemocompatibility of POSS-PCU films of various pore sizes with PTFE, which is a commercially available material used in most blood contacting devices...
November 2015: International Journal of Biochemistry & Cell Biology
Yasmin Farhatnia, Jun Hon Pang, Arnold Darbyshire, Ryan Dee, Aaron Tan, Alexander M Seifalian
Covered stents are stents wrapped with a thin polymeric membrane, and are typically used to treat vessel aneurysms and seal perforated arteries. Current covered stents suffer from restenosis due to limitations in material and fabrication methods which leaves metallic struts directly exposed to blood. We have developed a biocompatible and haemocompatible nanocomposite polymer, polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU). We devised a novel combination of ultrasonic spray atomisation system and dip-coating process to produce small calibre covered stents with metal struts fully embedded within the membrane, which also yields greater coating uniformity...
January 2016: Nanomedicine: Nanotechnology, Biology, and Medicine
D S T Chong, L A Turner, N Gadegaard, A M Seifalian, M J Dalby, G Hamilton
INTRODUCTION: Vascular graft materials in clinical use, such as polytetrafluoroethylene (PTFE) and Dacron, do not endothelialise and have low patency rates. The importance of an endothelial cell layer on the luminal surface of a vascular graft is well-known with surface topography and chemistry playing an important role. The aim of this study was to investigate the potential of plasma treatment and topographical structures on the luminal graft surface to enhance the self-endothelialisation potential of a nanocomposite vascular graft...
March 2015: European Journal of Vascular and Endovascular Surgery
Atefeh Solouk, Brian G Cousins, Fereshteh Mirahmadi, Hamid Mirzadeh, Mohammad Reza Jalali Nadoushan, Mohammad Ali Shokrgozar, Alexander M Seifalian
BACKGROUND: To date, there are no small internal diameter (<5mm) vascular grafts that are FDA approved for clinical use due to high failure rates from thrombosis and unwanted cell proliferation. The ideal conditions to enhance bioengineered grafts would be the blood contacting lumen of the bypass graft fully covered by endothelial cells (ECs). As a strategy towards this aim, we hypothesized that by immobilising biomolecules on the surface of the polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU) nanocomposite polymers, which contain binding sites and ligands for cell surface receptors similar to extracellular matrix (ECM) will positively influence the attachment and proliferation of ECs...
January 2015: Materials Science & Engineering. C, Materials for Biological Applications
Maqsood Ahmed, George Hamilton, Alexander M Seifalian
There is an acute clinical need for small-calibre (<6 mm) vascular grafts for surgery. The aim of this study was to evaluate the long-term performance of a small-calibre graft produced from a nanocomposite biomaterial, polyhedral oligomeric silsesquioxane poly(carbonate-urea)urethane (POSS-PCU), in a large animal model following Good Manufacturing Practice (GMP) and Good Laboratory Practice (GLP) protocols. Grafts were characterised and implanted into the left carotid artery (LCA) of senescent sheep (n = 11) for a period of 9 months...
November 2014: Biomaterials
Aaron Tan, Yasmin Farhatnia, Alexander M Seifalian
The field of nanotechnology and regenerative medicine has been progressing at a rapid pace. From theranostic nanoparticles to biomaterials, the possibilities seem endless. Researchers at the University College London have developed and patented a technology to manufacture a new breed of novel nanocomposite material called polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU). The enhanced biocompatibility, superior mechanical engineering properties, and augmented degradative resistance of POSS-PCU render it capable of functioning as a scaffold for bioartificial organs, nanoparticles for biomedical applications, and a coating for medical devices...
2013: Critical Reviews in Biomedical Engineering
Aaron Tan, Yasmin Farhatnia, Debbie Goh, Natasha G, Achala de Mel, Jing Lim, Swee-Hin Teoh, Andrey V Malkovskiy, Reema Chawla, Jayakumar Rajadas, Brian G Cousins, Michael R Hamblin, Mohammad S Alavijeh, Alexander M Seifalian
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...
December 2013: Biointerphases
Achala de Mel, Noora Naghavi, Brian G Cousins, Innes Clatworthy, George Hamilton, Arnold Darbyshire, Alexander M Seifalian
Cardiovascular implants must resist thrombosis and intimal hyperplasia, but they are prone to such patency limiting conditions during graft implantation and prior to endothelialisation. Nitric oxide (NO) released from the endothelium has a complex protective role in the cardiovascular system, and this study has addressed: (1) in situ NO release profiles from S-nitrosothiols ((S-Nitroso-N-acetylpenicillamine (SNAP) and (S-Nitrosoglutathione (GSNO)) incorporated into polyhedral oligomeric silsesquioxanepoly(carbonate-urea)urethane (POSS-PCU) coronary artery bypass grafts (CABG) in a physiological pulsatile flow, and (2) the determination of their interaction with endothelial progenitor cells (EPCs), smooth muscle cells, platelets, whole blood kinetics...
March 2014: Journal of Materials Science. Materials in Medicine
Aaron Tan, Debbie Goh, Yasmin Farhatnia, Natasha G, Jing Lim, Swee-Hin Teoh, Jayakumar Rajadas, Mohammad S Alavijeh, Alexander M Seifalian
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...
2013: PloS One
Maqsood Ahmed, Geoffrey Punshon, Arnold Darbyshire, Alexander M Seifalian
With the continuous and expanding use of implantable biomaterials in a clinical setting, this study aims to elucidate the influence of sterilization techniques on the material surface and bulk properties of two polyurethane nanocomposite biomaterials. Both solid samples and porous membranes of nondegradable polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) and a biodegradable poly(caprolactone-urea) urethane (POSS-PCL) were examined. Sterilization techniques included conventional steam sterilization (autoclaving), gamma irradiation, and disinfection via incubating with ethanol (EtOH) for 10 min or 24 h...
October 2013: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
Leonardo Guasti, Barbora Vagaska, Neil W Bulstrode, Alexander M Seifalian, Patrizia Ferretti
UNLABELLED: Scaffold cellularization for cartilage engineering can aid implant properties, their retention and minimize repeated intervention, particularly in paediatric reconstructive craniofacial surgery. We developed novel bionanoscaffolds using paediatric adipose tissue-derived stem cells (hADSCs), an accessible autologous cell source, and POSS-PCU. Little is known about cellular responses to this nanomaterial, though it was used in human. We assessed: 1) POSS-PCU cellularization and bioaffinity to hADSCs; 2) hADSC chondrogenic differentiation ability in POSS-PCU; 3) whether bionanoscaffolds became encased within a vascular network and/or vascularised...
February 2014: Nanomedicine: Nanotechnology, Biology, and Medicine
Leila Nayyer, Martin Birchall, Alexander M Seifalian, Gavin Jell
UNLABELLED: Auricular reconstruction using sculpted autologous costal cartilage is effective, but complex and time consuming and may incur donor site sequelae and morbidity. Conventional synthetic alternatives are associated with infection and extrusion in up to about 15% of cases. We present a novel POSS-PCU nanocomposite auricular scaffold, which aims to reduce extrusion rates by mimicking the elastic modulus of human ears and by encouraging desirable cellular interactions. The fabrication, physicochemical properties (including nanoscale topography) and cellular interactions of these scaffolds were compared to Medpor®, the current synthetic standard...
January 2014: Nanomedicine: Nanotechnology, Biology, and Medicine
Maqsood Ahmed, Geoffrey Punshon, Arnold Darbyshire, Alexander M Seifalian
With the continuous and expanding use of implantable biomaterials in a clinical setting, this study aims to elucidate the influence of sterilization techniques on the material surface and bulk properties of two polyurethane nanocomposite biomaterials. Both solid samples and porous membranes of nondegradable polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) and a biodegradable poly(caprolactone-urea) urethane (POSS-PCL) were examined. Sterilization techniques included conventional steam sterilization (autoclaving), gamma irradiation, and disinfection via incubating with ethanol (EtOH) for 10 min or 24 h...
May 22, 2013: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
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