Home About us Contact
|
Home About us Contact | ||
|
|
||
Fibrous Scaffolds (fibrous + scaffold)
Selected AbstractsA Solvent-Assisted Compression Molded of Poly(L -lactide)/Hydroxyapatite Electrospun Fibers for Robust Engineered Scaffold SystemsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2009Nguyen Dang Luong Abstract In an attempt to enhance the biocompatibility and mechanical strength of fibrous polymeric scaffold systems, nanocrystalline hydroxyapatite (HAp) particles were incorporated into the electrospun poly(L -lactide) (PLLA) fibers and then mechanically interlocked using a vapor-phase solvent adsorption method. The solvent-assisted compression molding substantially increased the tensile strength (from 4.61 to 12.63 MPa) and mechanical modulus (from 50.6 to 627.7 MPa) of the fibrous scaffold, which maintained the interstitial space between the fibers to allow the facile transport of nutrients and waste during cell growth and polymer biodegradation. Macrometer-sized pores (ca. 100,400,µm) were introduced into the scaffolds in a controlled fashion using the salt leaching/gas forming technique to give desired space for a facile cell implantation and growth. Overall, the developed methodology allows the polymer-based scaffold systems to be tailored for various applications in light of surface characteristics, mechanical strength, and pore size of engineered scaffolds. [source] Location-dependent controlled release kinetics of model hydrophobic compounds from mesoporous silicon/biopolymer composite fibersPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2009Dongmei Fan Abstract In this study, biodegradable mesoporous Si (BioSiliconTM) was loaded with cis-(2,2,-bipyridine) dichlororuthenium (II) (Ru complex) as a model hydrophobic compound. This ruthenium complex-loaded BioSiliconTM was either partially embedded on the surface of electrospun polycaprolactone (PCL) fibers or fully encapsulated within the fibers. To study release profiles in the above model delivery systems, porous Si/PCL constructs were soaked in DI water at 37 °C and the UV,Vis absorption spectrum of the supernatant was measured as a function of time. These results show that the Ru complex was released in a sustained manner over 7-day period. In addition, it is shown that the controlled-release of this complex depends on both the spatial location of the complex in the PCL fibrous scaffolds as well as the amount of Ru compound loaded in the mesoporous Si. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Electrospun poly(L -lactic acid)/hydroxyapatite composite fibrous scaffolds for bone tissue engineering,POLYMER INTERNATIONAL, Issue 2 2010Boontharika Chuenjitkuntaworn Abstract Poly(L -lactic acid) (PLLA) is one of the most studied synthetic biodegradable polymeric materials as a bone graft substitute. Taking into account the osteoconductive property of hydroxyapatite (HAp), we prepared fibrous matrices of PLLA without and with HAp particles in amounts of 0.25 or 0.50% (w/v, based on the volume of the base 15% w/v PLLA solution in 70:30 v/v dichloromethane/tetrahydrofuran). These fibrous matrices were assessed for their potential as substrates for bone cell culture. The presence of HAp in the composite fibre mats was confirmed using energy dispersive X-ray spectroscopy mapping. The average diameters of both neat PLLA and PLLA/HAp fibres, as determined using scanning electron microscopy, ranged between 2.3 and 3.5 µm, with the average spacing between adjacent fibres ranging between 5.7 and 8.5 µm. The porosity of these fibrous membranes was high (ca 97,98%). A direct cytotoxicity evaluation with L929 mouse fibroblasts indicated that the neat PLLA fibre mats released no substance at a level that was toxic to the cells. The presence of HAp particles at 0.50% w/v in the PLLA fibrous scaffolds not only promoted the attachment and the proliferation of MC3T3-E1 mouse pre-osteoblastic cells, but also increased the expression of osteocalcin mRNA and the extent of mineralization after the cells had been cultured on the scaffolds for 14 and 21 days, respectively. The results obtained suggested that the PLLA/HAp fibre mats could be materials of choice for bone tissue engineering. Copyright © 2009 Society of Chemical Industry [source] Electrospinning functional nanoscale fibers: a perspective for the futurePOLYMER INTERNATIONAL, Issue 3 2008Matthew T Hunley Abstract Over the past decade, electrospinning has grown from a small niche process to a widely used fiber formation technique. Applying a strong electric potential on a polymer solution or melt produces nanoscale fibers. These nanofibers form non-woven textile mats, oriented fibrous bundles and even three-dimensional structured scaffolds, all with large surface areas and high porosity. Major applications of electrospun membranes include tissue engineering, controlled drug delivery, sensing, separations, filtration, catalysis and nanowires. This perspective article highlights many recent advances in electrospun fibers for functional applications, with an emphasis on the advantages and proposed technologies for these non-woven fibrous scaffolds. Copyright © 2007 Society of Chemical Industry [source] Three-dimensional fibrous PLGA/HAp composite scaffold for BMP-2 deliveryBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2008Hemin Nie Abstract A protein loaded three-dimensional scaffold can be used for protein delivery and bone tissue regeneration. The main objective of this project was to develop recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded poly(D,L -lactide-co-glycolide)/hydroxylapatite (PLGA/HAp) composite fibrous scaffolds through a promising fabrication technique, electrospinning. In vitro release of BMP-2 from these scaffolds, and the attachment ability and viability of marrow derived messenchymal stem cells (MSCs) in the presence of the scaffolds were investigated. The PLGA/HAp composite scaffolds developed in this study exhibit good morphology and it was observed that HAp nanoparticles were homogeneously dispersed inside PLGA matrix within the scaffold. The composite scaffolds allowed sustained (2,8 weeks) release of BMP-2 whose release rate was accelerated with increasing HAp content. It was also shown that BMP-2 protein successfully maintained its integrity and natural conformations after undergoing the process of electrospinning. Cell culture experiments showed that the encapsulation of HAp could enhance cell attachment to scaffolds and lower cytotoxicity. Biotechnol. Bioeng. 2008;99: 223,234. © 2007 Wiley Periodicals, Inc. [source] Centrifugal seeding of mammalian cells in nonwoven fibrous matricesBIOTECHNOLOGY PROGRESS, Issue 1 2010Robin Ng Abstract Three-dimensional (3D) cell cultures have many advantages over two-dimensional cultures. However, seeding cells in 3D scaffolds such as nonwoven fibrous polyethylene terephthalate (PET) matrices has been a challenge task in tissue engineering and cell culture bioprocessing. In this study, a centrifugal seeding method was investigated to improve the cell seeding efficiency in PET matrices with two different porosities (93% and 88%). Both the centrifugal force and centrifugation time were found to affect the seeding efficiency. With an appropriate centrifugation speed, a high 80,90% cell seeding efficiency was achieved and the time to reach this high seeding efficiency was less than 5 min. The seeding efficiency was similar for matrices with different porosities, although the optimal seeding time was significantly shorter for the low-porosity scaffold. Post seeding cell viability was demonstrated by culturing colon cancer cells seeded in PET matrices for over 5 days. The centrifugal seeding method developed in this work can be used to efficiently and uniformly seed small fibrous scaffolds for applications in 3D cell-based assays for high-throughput screening. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] | |||||||||||||