The Experts below are selected from a list of 1716 Experts worldwide ranked by ideXlab platform
Seeram Ramakrishna - One of the best experts on this subject based on the ideXlab platform.
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the cellular response of nerve cells on poly l lysine coated plga mwcnts Aligned Nanofibers under electrical stimulation
Materials Science and Engineering: C, 2018Co-Authors: Seeram Ramakrishna, Jing Wang, Lingling Tian, Nuan Chen, Xiumei MoAbstract:Abstract Tissue engineering scaffold provide an effective alternative for peripheral nerve repair. Nanofibrous nerve conduits fabricated with various synthetic and natural materials have great potential to support nerve regeneration as a bridge between adjacent ends. The physical, chemical and electrical properties of the scaffolds affect the outcome of nerve regeneration and recovery of function. In this paper, a surface modified, electrically conductive, Aligned nanofibrous scaffold composed of poly(lactic-co-glycolic acid) (PLGA) and multi-walled carbon nanotubes (MWCNTs), referred to as L-PC_A was fabricated for nerve regeneration. The morphology, surface chemistry and hydrophilicity of Nanofibers were characterized by Scanning Electron Microscopy (SEM), Energy-dispersive X-ray (EDX) and water contact angle, respectively. The mechanical property of the nanofibrous scaffold was also evaluated using a universal materials tester. The effects of these scaffolds on PC12 cell adhesion, proliferation and neuronal differentiation were all evaluated. A hydrophilic surface was created by poly- l -lysine coating, which was able to provide a better environment for cell attachment. Furthermore Aligned fibers were proved to be able to guide PC12 cells and DRG neurons growing along the fiber direction and be beneficial for neurite outgrowth. The cellular responses of PC12 cells and DRG neurons on L-PC_A scaffold under electrical stimulation were evaluated by neurofilament proteins expression. As a result, the PC12 cells and DRG neurons stimulated with electrical shock showed longer neurite length, indicating that electrical stimulation with a voltage of 40 mV based on the scaffold with MWCNTs could enhance the neurite extension. Moreover, the cellular response of Schwann cells including cell attachment, proliferation and MBP expression were also enhanced with the synergistic effect of Aligned Nanofibers and electrical stimulation. In summary, the L-PC_A nanofibrous scaffold supported the cellular response of nerve cells in terms of cell proliferation, differentiation, neurite outgrowth, and myelination in the presence of electrical stimulation, which could be a potential candidate for nerve regeneration application.
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electrospun Aligned phbv collagen Nanofibers as substrates for nerve tissue engineering
Biotechnology and Bioengineering, 2013Co-Authors: Molamma P Prabhakaran, Elham Vatankhah, Seeram RamakrishnaAbstract:Nerve regeneration following the injury of nerve tissue remains a major issue in the therapeutic medical field. Various bio-mimetic strategies are employed to direct the nerve growth in vitro, among which the chemical and topographical cues elicited by the scaffolds are crucial parameters that is primarily responsible for the axon growth and neurite extension involved in nerve regeneration. We carried out electrospinning for the first time, to fabricate both random and Aligned Nanofibers of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate; PHBV) and composite PHBV/collagen Nanofibers with fiber diameters in the range of 386-472 nm and 205-266 nm, respectively. To evaluate the potential of electrospun Aligned Nanofibers of PHBV and composite scaffolds as a substrate for nerve regeneration, we cultured nerve cells (PC12) and studied the biocompatibility effect along with neurite extension by immunostaining studies. Cell proliferation assays showed 40.01% and 5.48% higher proliferation of nerve cells on Aligned PHBV/Coll50:50 Nanofibers compared to cell proliferation on Aligned PHBV and PHBV/Col75:25 Nanofibers, respectively. Aligned Nanofibers of PHBV/Coll provided contact guidance to direct the orientation of nerve cells along the direction of the fibers, thus endowing elongated cell morphology, with bi-polar neurite extensions required for nerve regeneration. Results showed that Aligned PHBV/Col Nanofibers are promising substrates than the random PHBV/Col Nanofibers for application as bioengineered grafts for nerve tissue regeneration.
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Electrospun Aligned PHBV/collagen Nanofibers as substrates for nerve tissue engineering
Biotechnology and Bioengineering, 2013Co-Authors: Molamma P Prabhakaran, Elham Vatankhah, Seeram RamakrishnaAbstract:: Nerve regeneration following the injury of nerve tissue remains a major issue in the therapeutic medical field. Various bio-mimetic strategies are employed to direct the nerve growth in vitro, among which the chemical and topographical cues elicited by the scaffolds are crucial parameters that is primarily responsible for the axon growth and neurite extension involved in nerve regeneration. We carried out electrospinning for the first time, to fabricate both random and Aligned Nanofibers of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate; PHBV) and composite PHBV/collagen Nanofibers with fiber diameters in the range of 386-472 nm and 205-266 nm, respectively. To evaluate the potential of electrospun Aligned Nanofibers of PHBV and composite scaffolds as a substrate for nerve regeneration, we cultured nerve cells (PC12) and studied the biocompatibility effect along with neurite extension by immunostaining studies. Cell proliferation assays showed 40.01% and 5.48% higher proliferation of nerve cells on Aligned PHBV/Coll50:50 Nanofibers compared to cell proliferation on Aligned PHBV and PHBV/Col75:25 Nanofibers, respectively. Aligned Nanofibers of PHBV/Coll provided contact guidance to direct the orientation of nerve cells along the direction of the fibers, thus endowing elongated cell morphology, with bi-polar neurite extensions required for nerve regeneration. Results showed that Aligned PHBV/Col Nanofibers are promising substrates than the random PHBV/Col Nanofibers for application as bioengineered grafts for nerve tissue regeneration.
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guided orientation of cardiomyocytes on electrospun Aligned Nanofibers for cardiac tissue engineering
Journal of Biomedical Materials Research Part B, 2011Co-Authors: Molamma P Prabhakaran, Seeram RamakrishnaAbstract:Cardiac tissue engineering (TE) is one of the most promising strategies to reconstruct the infarct myocardium and the major challenge involves producing a bioactive scaffold with anisotropic properties that assist in cell guidance to mimic the heart tissue. In this study, random and Aligned poly(e-caprolactone)/gelatin (PG) composite nanofibrous scaffolds were electrospun to structurally mimic the oriented extracellular matrix (ECM). Morphological, chemical and mechanical properties of the electrospun PG Nanofibers were evaluated by scanning electron microscopy (SEM), water contact angle, attenuated total reflectance Fourier transform infrared spectroscopy and tensile measurements. Results indicated that PG nanofibrous scaffolds possessed smaller fiber diameters (239 ± 37 nm for random fibers and 269 ± 33 nm for Aligned fibers), increased hydrophilicity, and lower stiffness compared to electrospun PCL Nanofibers. The Aligned PG Nanofibers showed anisotropic wetting characteristics and mechanical properties, which closely match the requirements of native cardiac anisotropy. Rabbit cardiomyocytes were cultured on electrospun random and Aligned Nanofibers to assess the biocompatibility of scaffolds, together with its potential for cell guidance. The SEM and immunocytochemical analysis showed that the Aligned PG scaffold greatly promoted cell attachment and alignment because of the biological components and ordered topography of the scaffolds. Moreover, we concluded that the Aligned PG nanofibrous scaffolds could be more promising substrates suitable for the regeneration of infarct myocardium and other cardiac defects. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
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producing continuous twisted yarn from well Aligned Nanofibers by water vortex
Polymer Engineering and Science, 2011Co-Authors: Maryam Yousefzadeh, Masoud Latifi, Mohammad Amanitehran, Seeram RamakrishnaAbstract:A new technology based on the liquid support system is introduced for fabricating continuous twisted nanofibrous yarn. In this novel technique, the electrospun yarn was collected from the top of the water vortex such that it can be twisted simultaneously during yarn production. Our study demonstrated the feasibility of the technique for producing continuous twisted yarn from well Aligned Nanofibers. It is shown that the system can be modified to have different yarn counts with various twists. Further, significant improvement can be seen in the strength and strain when nanofibrous yarn is twisted compared to non-twisted yarn. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Sing Yian Chew - One of the best experts on this subject based on the ideXlab platform.
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three dimensional Aligned Nanofibers hydrogel scaffold for controlled non viral drug gene delivery to direct axon regeneration in spinal cord injury treatment
Scientific Reports, 2017Co-Authors: Lan Huong Nguyen, Wutian Wu, Jun Wang, Sing Yian ChewAbstract:Spinal cord injuries (SCI) often lead to persistent neurological dysfunction due to failure in axon regeneration. Unfortunately, currently established treatments, such as direct drug administration, do not effectively treat SCI due to rapid drug clearance from our bodies. Here, we introduce a three-dimensional Aligned Nanofibers-hydrogel scaffold as a bio-functionalized platform to provide sustained non-viral delivery of proteins and nucleic acid therapeutics (small non-coding RNAs), along with synergistic contact guidance for nerve injury treatment. A hemi-incision model at cervical level 5 in the rat spinal cord was chosen to evaluate the efficacy of this scaffold design. Specifically, Aligned axon regeneration was observed as early as one week post-injury. In addition, no excessive inflammatory response and scar tissue formation was triggered. Taken together, our results demonstrate the potential of our scaffold for neural tissue engineering applications.
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Three-dimensional Aligned Nanofibers-hydrogel scaffold for controlled non-viral drug/gene delivery to direct axon regeneration in spinal cord injury treatment.
Scientific Reports, 2017Co-Authors: Lan Huong Nguyen, Wutian Wu, Jun Wang, Sing Yian ChewAbstract:Spinal cord injuries (SCI) often lead to persistent neurological dysfunction due to failure in axon regeneration. Unfortunately, currently established treatments, such as direct drug administration, do not effectively treat SCI due to rapid drug clearance from our bodies. Here, we introduce a three-dimensional Aligned Nanofibers-hydrogel scaffold as a bio-functionalized platform to provide sustained non-viral delivery of proteins and nucleic acid therapeutics (small non-coding RNAs), along with synergistic contact guidance for nerve injury treatment. A hemi-incision model at cervical level 5 in the rat spinal cord was chosen to evaluate the efficacy of this scaffold design. Specifically, Aligned axon regeneration was observed as early as one week post-injury. In addition, no excessive inflammatory response and scar tissue formation was triggered. Taken together, our results demonstrate the potential of our scaffold for neural tissue engineering applications.
Samuel I Stupp - One of the best experts on this subject based on the ideXlab platform.
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a tenascin c mimetic peptide amphiphile nanofiber gel promotes neurite outgrowth and cell migration of neurosphere derived cells
Acta Biomaterialia, 2016Co-Authors: Eric J Berns, Zaida Alvarez, Joshua E Goldberger, Job Boekhoven, John A Kessler, Georg H Kuhn, Samuel I StuppAbstract:Abstract Biomimetic materials that display natural bioactive signals derived from extracellular matrix molecules like laminin and fibronectin hold promise for promoting regeneration of the nervous system. In this work, we investigated a biomimetic peptide amphiphile (PA) presenting a peptide derived from the extracellular glycoprotein tenascin-C, known to promote neurite outgrowth through interaction with β1 integrin. The tenascin-C mimetic PA (TN-C PA) was found to self-assemble into supramolecular Nanofibers and was incorporated through co-assembly into PA gels formed by highly Aligned Nanofibers. TN-C PA content in these gels increased the length and number of neurites produced from neurons differentiated from encapsulated P19 cells. Furthermore, gels containing TN-C PA were found to increase migration of cells out of neurospheres cultured on gel coatings. These bioactive gels could serve as artificial matrix therapies in regions of neuronal loss to guide neural stem cells and promote through biochemical cues neurite extension after differentiation. One example of an important target would be their use as biomaterial therapies in spinal cord injury. Statement of Significance Tenascin-C is an important extracellular matrix molecule in the nervous system and has been shown to play a role in regenerating the spinal cord after injury and guiding neural progenitor cells during brain development, however, minimal research has been reported exploring the use of biomimetic biomaterials of tenascin-C. In this work, we describe a selfassembling biomaterial system in which peptide amphiphiles present a peptide derived from tenascin-C that promotes neurite outgrowth. Encapsulation of neurons in hydrogels of Aligned Nanofibers formed by tenascin-C-mimetic peptide amphiphiles resulted in enhanced neurite outgrowth. Additionally, these peptide amphiphiles promoted migration of neural progenitor cells cultured on nanofiber coatings. Tenascin-C biomimetic biomaterials such as the one described here have significant potential in neuroregenerative medicine.
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tubular hydrogels of circumferentially Aligned Nanofibers to encapsulate and orient vascular cells
Biomaterials, 2012Co-Authors: Mark T Mcclendon, Samuel I StuppAbstract:There is a great clinical need for tissue engineered blood vessels that could be used to replace or bypass damaged arteries. The success of such grafts will depend strongly on their ability to mimic the cellular and matrix organization found in native arteries, but currently available cell scaffolds such as electrospun fibers or hydrogels lack the ability to simultaneously encapsulate and align cells. Our laboratory has recently developed liquid crystalline solutions of peptide amphiphile Nanofibers that form Aligned domains at exceedingly low concentrations ( 99% water by weight, the cells have abundant room for proliferation and remodeling. In contrast to previously reported arterial cell scaffolds, this new material can encapsulate cells and direct cellular organization without the requirement of external stimuli or gel compaction.
Yong Huang - One of the best experts on this subject based on the ideXlab platform.
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electrospun tubular scaffold with circumferentially Aligned Nanofibers for regulating smooth muscle cell growth
ACS Applied Materials & Interfaces, 2014Co-Authors: Yanming Wang, Jing Qiao, Ye Tian, Man Wu, Wei Zhang, Yong HuangAbstract:Simulation for the smooth muscle layer of blood vessel plays a key role in tubular tissue engineering. However, fabrication of biocompatible tube with defined inner nano/micro-structure remains a challenge. Here, we show that a biocompatible polymer tube from poly(l-lactide) (PLLA) and polydimethylsiloxane (PDMS) can be prepared by using electrospinning technique, with assistance of rotating collector and parallel auxiliary electrode. The tube has circumferentially Aligned PLLA fibers in the inner surface for cell growth regulation and has a PDMS coating for better compressive property. MTT assay showed the composite PLLA/PDMS tube was suitable for various cells growth. In vitro smooth muscle cells (SMCs) cultured in the tube showed that the Aligned PLLA fibers could induce SMCs’ orientation, and different expression of α-SMA and OPN genes were observed on the Aligned and random PLLA fibers, respectively. The successful fabrication of composite PLLA/PDMS tubular scaffold for regulating smooth muscle cells...
Lan Huong Nguyen - One of the best experts on this subject based on the ideXlab platform.
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three dimensional Aligned Nanofibers hydrogel scaffold for controlled non viral drug gene delivery to direct axon regeneration in spinal cord injury treatment
Scientific Reports, 2017Co-Authors: Lan Huong Nguyen, Wutian Wu, Jun Wang, Sing Yian ChewAbstract:Spinal cord injuries (SCI) often lead to persistent neurological dysfunction due to failure in axon regeneration. Unfortunately, currently established treatments, such as direct drug administration, do not effectively treat SCI due to rapid drug clearance from our bodies. Here, we introduce a three-dimensional Aligned Nanofibers-hydrogel scaffold as a bio-functionalized platform to provide sustained non-viral delivery of proteins and nucleic acid therapeutics (small non-coding RNAs), along with synergistic contact guidance for nerve injury treatment. A hemi-incision model at cervical level 5 in the rat spinal cord was chosen to evaluate the efficacy of this scaffold design. Specifically, Aligned axon regeneration was observed as early as one week post-injury. In addition, no excessive inflammatory response and scar tissue formation was triggered. Taken together, our results demonstrate the potential of our scaffold for neural tissue engineering applications.
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Three-dimensional Aligned Nanofibers-hydrogel scaffold for controlled non-viral drug/gene delivery to direct axon regeneration in spinal cord injury treatment.
Scientific Reports, 2017Co-Authors: Lan Huong Nguyen, Wutian Wu, Jun Wang, Sing Yian ChewAbstract:Spinal cord injuries (SCI) often lead to persistent neurological dysfunction due to failure in axon regeneration. Unfortunately, currently established treatments, such as direct drug administration, do not effectively treat SCI due to rapid drug clearance from our bodies. Here, we introduce a three-dimensional Aligned Nanofibers-hydrogel scaffold as a bio-functionalized platform to provide sustained non-viral delivery of proteins and nucleic acid therapeutics (small non-coding RNAs), along with synergistic contact guidance for nerve injury treatment. A hemi-incision model at cervical level 5 in the rat spinal cord was chosen to evaluate the efficacy of this scaffold design. Specifically, Aligned axon regeneration was observed as early as one week post-injury. In addition, no excessive inflammatory response and scar tissue formation was triggered. Taken together, our results demonstrate the potential of our scaffold for neural tissue engineering applications.
