scholarly journals Particulate Release From Nanoparticle-Loaded Shape Memory Polymer Foams

2017 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam L. Nathan ◽  
Grace K. Fletcher ◽  
Mary Beth B. Monroe ◽  
Wonjun Hwang ◽  
Scott M. Herting ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
High Surface ◽  
High Surface Area ◽  
Vascular Occlusion ◽  
Peripheral Vascular ◽  
Abdominal Aortic ◽  
Guidance Documents ◽  
High Surface Area Materials ◽  
Highly Porous

Highly porous, open-celled shape memory polymer (SMP) foams are being developed for a number of vascular occlusion devices. Applications include abdominal aortic and neurovascular aneurysm or peripheral vascular occlusion. A major concern with implanting these high surface area materials in the vasculature is the potential to generate unacceptable particulate burden, in terms of number, size, and composition. This study demonstrates that particulate numbers and sizes in SMP foams are in compliance with limits stated by the most relevant standard and guidance documents. Particulates were quantified in SMP foams as made, postreticulation, and after incorporating nanoparticles intended to increase material toughness and improve radiopacity. When concentrated particulate treatments were administered to fibroblasts, they exhibited high cell viability (100%). These results demonstrate that the SMP foams do not induce an unacceptable level of risk to potential vascular occlusion devices due to particulate generation.

scholarly journals Enhanced X-ray Visibility of Shape Memory Polymer Foam Using Iodine Motifs and Tantalum Microparticles

2021 ◽  
Vol 5 (1) ◽  
pp. 14
Author(s):  
Lindy K. Jang ◽  
Landon D. Nash ◽  
Grace K. Fletcher ◽  
Thomas Cheung ◽  
Andrew Soewito ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
High Surface ◽  
High Surface Area ◽  
Polymer Foam ◽  
Brain Aneurysm ◽  
X Ray ◽  
Safe Delivery ◽  
Aneurysm Embolization

Shape memory polymer (SMP) foams are porous materials with high surface area and large volumetric expansion capabilities that are well suited for endovascular occlusion applications, including brain aneurysm embolization. However, many polyurethane SMP foams are inherently radiolucent when X-ray visibility is required to ensure the safe delivery of the foam to the targeted aneurysm site using fluoroscopy. Here, highly radio-dense tantalum microparticles were added to a previously reported triiodobenzene-containing SMP foam (ATIPA foam) premix to fabricate ATIPA foam-tantalum composites (AT_T). The AT_T foams showed comparable glass transition temperatures, faster expansion profiles, increased X-ray visibility, good cytocompatibility, and faster oxidative degradation compared to the control ATIPA foam without tantalum. The mechanical properties were improved up to 4 vol% tantalum and the X-ray visibility was most appropriate for the 2 vol% (AT_2%T) and 4 vol% (AT_4%T) tantalum foams. E-beam sterilization did not impair the critical properties of the ATIPA foams. Overall, AT_2%T was the optimal foam composition for neurovascular prototypes due to its high oxidative stability in vitro compared to previous low-density SMP foams. The AT_T foams are very promising materials with high toughness and sufficient X-ray visibility for use as neurovascular embolization devices.

scholarly journals Highly Porous Carbon Materials from Biomass by Chemical and Carbonization Method: A Comparison Study

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Wan Nor Roslam Wan Isahak ◽  
Mohamed Wahab Mahamed Hisham ◽  
Mohd Ambar Yarmo
Keyword(s):  
Sulfuric Acid ◽  
Thermal Behavior ◽  
Surface Area ◽  
Porous Carbon ◽  
High Surface ◽  
High Surface Area ◽  
Empty Fruit Bunches ◽  
Heating Treatment ◽  
Concentrated Sulfuric Acid ◽  
Highly Porous

Porous carbon obtained by dehydrating agent, concentrated sulfuric acid (H2SO4), from biomass containing high cellulose (filter paper (FP), bamboo waste, and empty fruit bunches (EFB)) shows very high surface area and better thermal behavior. At room temperature (without heating), treatment of H2SO4removed all the water molecules in the biomass and left the porous carbon without emitting any gaseous byproducts. Brunauer-Emmett-Teller (BET) surface analysis has shown that bamboo-based carbon has good properties with higher surface area (507.8 m2/g), micropore area (393.3 m2/g), and better thermal behavior (compared to FP and EFB) without any activation or treatment process. By acid treatment of biomass, it was shown that higher carbon composition obtained from FP (85.30%), bamboo (77.72%), and EFB (76.55%) is compared to carbon from carbonization process. Under optimal sulfuric acid (20 wt.%) uses, high carbon yield has been achieved for FP (47.85 wt.%), bamboo (62.4 wt.%), and EFB (55.4 wt.%).

scholarly journals A review on advanced nanofiber technology for membrane distillation

2019 ◽  
Vol 14 ◽  
pp. 155892501882490 ◽  
Author(s):  
Fatma Yalcinkaya
Keyword(s):  
Tissue Engineering ◽  
Surface Area ◽  
Wound Dressing ◽  
High Surface ◽  
High Surface Area ◽  
Membrane Distillation ◽  
Operating Parameters ◽  
Polymeric Nanofibers ◽  
Highly Porous ◽  
Comprehensive Study

The importance of the nanofiber webs increases rapidly due to their highly porous structure, narrow pore size, and distribution; specific surface area and compatibility with inorganics. Electrospinning has been introduced as one of the most efficient technique for the fabrication of polymeric nanofibers due to its ability to fabricate nanostructures with unique properties such as a high surface area and porosity. The process and the operating parameters affect the nanofiber fabrication and the application of nanofibers in various fields, such as sensors, tissue engineering, wound dressing, protective clothes, filtration, desalination, and distillation. In this review, a comprehensive study is presented on the parameters of electrospinning system including applications. More emphasis is given to the application of nanofibers in membrane distillation (MD). The research developments and the current situation of the nanofiber webs in MD are also discussed.

High surface area submicrometer-sized β-SiC particles grown by shape memory synthesis method

2005 ◽  
Vol 14 (8) ◽  
pp. 1353-1360 ◽  
Author(s):  
Nicolas Keller ◽  
Olivier Reiff ◽  
Valérie Keller ◽  
Marc J. Ledoux
Keyword(s):  
Shape Memory ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Synthesis Method ◽  
Sic Particles ◽  
Memory Synthesis

Highly porous 3D sponge-like shape memory polymer for tissue engineering application with remote actuation potential

2019 ◽  
Vol 184 ◽  
pp. 107874 ◽  
Author(s):  
Mohadeseh Zare ◽  
Nader Parvin ◽  
Molamma P. Prabhakaran ◽  
Jamshid Aghazadeh Mohandesi ◽  
Seeram Ramakrishna
Keyword(s):  
Tissue Engineering ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Engineering Application ◽  
Tissue Engineering Application ◽  
Remote Actuation ◽  
Highly Porous

scholarly journals Cigarette butt-derived carbons have ultra-high surface area and unprecedented hydrogen storage capacity

2017 ◽  
Vol 10 (12) ◽  
pp. 2552-2562 ◽  
Author(s):  
Troy Scott Blankenship ◽  
Robert Mokaya
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
Storage Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogen Storage Capacity ◽  
Cigarette Butt ◽  
Highly Porous

Cigarette butt derived carbons are highly porous (4310 m2 g−1 and 2.09 cm3 g−1) with record levels of hydrogen storage.

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