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Articles 1 - 9 of 9
Full-Text Articles in Biochemical and Biomolecular Engineering
3d Differentiation Of Neural Stem Cells In Macroporous Photopolymerizable Hydrogel Scaffolds, Nic Leipzig
3d Differentiation Of Neural Stem Cells In Macroporous Photopolymerizable Hydrogel Scaffolds, Nic Leipzig
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Neural stem/progenitor cells (NSPCs) are the stem cell of the adult central nervous system (CNS). These cells are able to differentiate into the major cell types found in the CNS (neurons, oligodendrocytes, astrocytes), thus NSPCs are the mechanism by which the adult CNS could potentially regenerate after injury or disorder. Microenviromental factors are critical for guiding NSPC differentiation and are thus important for neural tissue engineering. In this study, D-mannitol crystals were mixed with photocrosslinkable methacrylamide chitosan (MAC) as a porogen to enhance pore size during hydrogel formation. D-mannitol was admixed to MAC at 5, 10 and 20 wt% D-mannitol …
Fabrication And Degradation Of Electrospun Scaffolds From L-Tyrosine Based Polyurethane Blends For Tissue Engineering Applications, Lingyun Liu
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
It is important to control the degradation rate of a tissue-engineered scaffold so that the scaffold will degrade in an appropriate matching rate as the tissue cells grow in. A set of potential tissue engineering scaffolds with controllable rates of degradation were fabricated from blends of two biocompatible, biodegradable L-tyrosine-based polyurethanes (PEG1000-HDI-DTH and PCL1250-HDI-DTH) using the electrospinning process. The scaffolds were characterized by mat morphology, fiber diameter, diameter distribution, pore size, and hydrolytic degradation behavior. The majority of the scaffolds, despite having radically different chemical compositions, possessed no statistical difference with pore sizes and fiber diameters. The degradation pattern observed …
Polymorphic Structures Of Alzheimer's Beta-Amyloid Globulomers, Jie Zheng
Polymorphic Structures Of Alzheimer's Beta-Amyloid Globulomers, Jie Zheng
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Misfolding and self-assembly of Amyloid-β (Aβ) peptides into amyloid fibrils is pathologically linked to the development of Alzheimer's disease. Polymorphic Aβ structures derived from monomers to intermediate oligomers, protofilaments, and mature fibrils have been often observed in solution. Some aggregates are on-pathway species to amyloid fibrils, while the others are off-pathway species that do not evolve into amyloid fibrils. Both on-pathway and off-pathway species could be biologically relevant species. But, the lack of atomic-level structural information for these Aβ species leads to the difficulty in the understanding of their biological roles in amyloid toxicity and amyloid formation.
Hemocompatibility Of Silicon-Based Substrates For Biomedical Implant Applications, Lingyan Liu
Hemocompatibility Of Silicon-Based Substrates For Biomedical Implant Applications, Lingyan Liu
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Silicon membranes with highly uniform nanopore sizes fabricated using microelectromechanical systems (MEMS) technology allow for the development of miniaturized implants such as those needed for renal replacement therapies. However, the blood compatibility of silicon has thus far been an unresolved issue in the use of these substrates in implantable biomedical devices. We report the results of hemocompatibility studies using bare silicon, polysilicon, and modified silicon substrates. The surface modifications tested have been shown to reduce protein and/or platelet adhesion, thus potentially improving biocompatibility of silicon. Hemocompatibility was evaluated under four categories—coagulation (thrombin–antithrombin complex, TAT generation), complement activation (complement protein, C3a …
Surface Hydration: Principles And Applications Toward Low-Fouling/Nonfouling Biomaterials, Lingyan Liu, Jie Zheng
Surface Hydration: Principles And Applications Toward Low-Fouling/Nonfouling Biomaterials, Lingyan Liu, Jie Zheng
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Surface resistance to nonspecific protein adsorption, cell/bacterial adhesion, and biofilm formation is critical for the development and performance of biomedical and analytical devices. Significant needs and efforts have been made in the development of biocompatible and bioactive materials for antifouling surfaces, but much of the work retains an empirical flavor due to the complexity of experiments and the lack of robust theoretical models. In this review, two major classes of nonfouling materials (i.e. hydrophilic and zwitterionic materials) and associated basic nonfouling mechanisms and practical examples are discussed. Highly hydrated chemical groups with optimized physical properties of the surface, along with …
Ptau Bimetallic Heteronanostructures Made By Post-Synthesis Modification Of Pt-On-Au Nanoparticles, Zhenmeng Peng
Ptau Bimetallic Heteronanostructures Made By Post-Synthesis Modification Of Pt-On-Au Nanoparticles, Zhenmeng Peng
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
imetallic PtAu heteronanostructures have been synthesized from Pt-on-Au nanoparticles, which were made from platinum acetylacetonate and gold nanoparticles. Using the Pt-on-Au nanoparticles as precursors, Ptsurface rich PtAu bimetallic heteronanostructures can be produced through controlled thermal treatments, as confirmed by field emission high-resolution transmission electron microscopy (HR-TEM) and elemental mapping using a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM). Oxidation of formic acid was used as a model reaction to demonstrate the effects of varying composition and surface structure on the catalytic performance of PtAu bimetallic nanostructures. Cyclic voltammetry (CV) showed that these carbon-supported PtAu heteronanostructures were much more active …
Promoting Neuron Adhesion And Growth, Laura M. Y. Yu, Nic Leipzig, Molly S. Schoichet
Promoting Neuron Adhesion And Growth, Laura M. Y. Yu, Nic Leipzig, Molly S. Schoichet
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
During nervous system development, the extracellular matrix (ECM) plays a pivotal role offering anchorage points to maturing neurons and neurites, as well as a permissive environment for tissue formation. Thus enhancement of cell adhesion is often an important criterion when designing biomaterials for neural tissue engineering. In addition to functionalizing biomaterials with ECM-derived cell adhesive molecules, there is emerging evidence that indicates the surface topography, stiffness, and electrical properties play an important role in neuron adhesion and neurite outgrowth. We describe recent developments in biomaterials modification for simulating the microenvironment in order to promote neuron adhesion and growth, as well …
The Effects Of Tgf-Beta1 And Igf-I On The Biomechanics And Cytoskeleton Of Single Chondrocytes, Nic Leipzig
The Effects Of Tgf-Beta1 And Igf-I On The Biomechanics And Cytoskeleton Of Single Chondrocytes, Nic Leipzig
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Objective Ascertaining how mechanical forces and growth factors mediate normal and pathologic processes in single chondrocytes can aid in developing strategies for the repair and replacement of articular cartilage destroyed by injury or disease. This study examined effects of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor-I (IGF-I) on the biomechanics and cytoskeleton of single zonal chondrocytes. Method Superficial and middle/deep bovine articular chondrocytes were seeded on tissue culture treated plastic for 3 and 18 h and treated with TGF-β1 (5 ng/mL), IGF-I (100 ng/mL), or a combination of TGF-β1 (5 ng/mL) + IGF-I (100 ng/mL). Single chondrocytes from all …
Designing A Nanotube Using Naturally Occurring Protein Building Blocks, Jie Zheng
Designing A Nanotube Using Naturally Occurring Protein Building Blocks, Jie Zheng
Chemical, Biomolecular, and Corrosion Engineering Faculty Research
Here our goal is to carry out nanotube design using naturally occurring protein building blocks. Inspection of the protein structural database reveals the richness of the conformations of proteins, their parts, and their chemistry. Given target functional protein nanotube geometry, our strategy involves scanning a library of candidate building blocks, combinatorially assembling them into the shape and testing its stability. Since self-assembly takes place on time scales not affordable for computations, here we propose a strategy for the very first step in protein nanotube design: we map the candidate building blocks onto a planar sheet and wrap the sheet around …