364 results found
von Erlach TC, Hedegaard MAB, Stevens MM, 2015, High resolution Raman spectroscopy mapping of stem cell micropatterns, ANALYST, Vol: 140, Pages: 1798-1803, ISSN: 0003-2654
Azevedo MM, Tsigkou O, Nair R, et al., 2015, Hypoxia Inducible Factor-Stabilizing Bioactive Glasses for Directing Mesenchymal Stem Cell Behavior, TISSUE ENGINEERING PART A, Vol: 21, Pages: 382-389, ISSN: 1937-3341
Jumeaux C, Chapman R, Chandrawati R, et al., 2015, Synthesis and self-assembly of temperature-responsive copolymers based on N-vinylpyrrolidone and triethylene glycol methacrylate, POLYMER CHEMISTRY, Vol: 6, Pages: 4116-4122, ISSN: 1759-9954
Duda GN, Grainger DW, Frisk ML, et al., 2014, Changing the Mindset in Life Sciences Toward Translation: A Consensus, SCIENCE TRANSLATIONAL MEDICINE, Vol: 6, ISSN: 1946-6234
Chapman R, Gormley AJ, Herpoldt K-L, et al., 2014, Highly controlled open vessel RAFT polymerizations byenzyme degassing, Macromolecules, Vol: 47, Pages: 8541-8547, ISSN: 0024-9297
Gormley AJ, Chapman R, Stevens MM, 2014, Polymerization amplified detection for nanoparticle-based biosensing, Nano Letters, Vol: 14, Pages: 6368-6373, ISSN: 1530-6992
Howes PD, Chandrawati R, Stevens MM, 2014, Colloidal nanoparticles as advanced biological sensors, Science, Vol: 346, ISSN: 0036-8075
Colloidal nanoparticle biosensors have received intense scientific attention and offer promising applications in both research and medicine. We review the state of the art in nanoparticle development, surface chemistry, and biosensing mechanisms, discussing how a range of technologies are contributing toward commercial and clinical translation. Recent examples of success include the ultrasensitive detection of cancer biomarkers in human serum and in vivo sensing of methyl mercury. We identify five key materials challenges, including the development of robust mass-scale nanoparticle synthesis methods, and five broader challenges, including the use of simulations and bioinformatics-driven experimental approaches for predictive modeling of biosensor performance. The resultant generation of nanoparticle biosensors will form the basis of high-performance analytical assays, effective multiplexed intracellular sensors, and sophisticated in vivo probes.
Smith EL, Kanczler JM, Gothard D, et al., 2014, Evaluation of skeletal tissue repair, Part 1: Assessment of novel growth-factor-releasing hydrogels in an ex vivo chick femur defect model, ACTA BIOMATERIALIA, Vol: 10, Pages: 4186-4196, ISSN: 1742-7061
Smith EL, Kanczler JM, Gothard D, et al., 2014, Evaluation of skeletal tissue repair, Part 2: Enhancement of skeletal tissue repair through dual-growth-factor-releasing hydrogels within an ex vivo chick femur defect model, ACTA BIOMATERIALIA, Vol: 10, Pages: 4197-4205, ISSN: 1742-7061
de la Rica R, Chow LW, Horejs C-M, et al., 2014, A designer peptide as a template for growing Au nanoclusters, CHEMICAL COMMUNICATIONS, Vol: 50, Pages: 10648-10650, ISSN: 1359-7345
Xie H-N, Lin Y, Mazo M, et al., 2014, Identification of intracellular gold nanoparticles using surface-enhanced Raman scattering, Nanoscale, Vol: 6, Pages: 12403-12407, ISSN: 2040-3364
The identification of intracellular distributions of noble metal nanoparticles is of great utility for many biomedical applications. We present an effective method to distinguish intracellular from extracellular nanoparticles by selectively quenching the SERS signals from dye molecules adsorbed onto star-shaped gold nanoparticles that have not been internalized by cells.
Ren J, Blackwood KA, Doustgani A, et al., 2014, Melt-electrospun polycaprolactone strontium-substituted bioactive glass scaffolds for bone regeneration, JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, Vol: 102, Pages: 3140-3153, ISSN: 1549-3296
Su L, Cloyd KL, Arya S, et al., 2014, Raman spectroscopic evidence of tissue restructuring in heat-induced tissue fusion, JOURNAL OF BIOPHOTONICS, Vol: 7, Pages: 713-723, ISSN: 1864-063X
Chow LW, Armgarth A, St-Pierre JP, et al., 2014, Biomimetic materials: Peptide-directed spatial organization of biomolecules in dynamic gradient scaffolds (adv. Healthcare mater. 9/2014)., Adv Healthc Mater, Vol: 3
Peptide-polymer conjugates that specifically and dynamically bind glycosaminoglycans are used to functionalize the surface of biodegradable electrospun fiber scaffolds. The versatile platform presented by L. W. Chow, M. M. Stevens, and colleagues on page 1381 can be used to recreate gradients of ECM-like biomolecule organization within scaffolds to achieve more functional and clinically relevant tissue-engineered constructs.
Todorova N, Chiappini C, Mager M, et al., 2014, Surface presentation of functional peptides in solution determines cell internalization efficiency of TAT conjugated nanoparticles, Nano Letters, Vol: 14, Pages: 5229-5237, ISSN: 1530-6984
Functionalizing nanoparticles with cell-penetrating peptides is a popular choice for cellular delivery. We investigated the effects of TAT peptide concentration and arrangement in solution on functionalized nanoparticles’ efficacy for membrane permeation. We found that cell internalization correlates with the positive charge distribution achieved prior to nanoparticle encountering interactions with membrane. We identified a combination of solution based properties required to maximize the internalization efficacy of TAT-functionalized nanoparticles.
Cecchin D, de la Rica R, Bain RES, et al., 2014, Plasmonic ELISA for the detection of gp120 at ultralow concentrations with the naked eye, NANOSCALE, Vol: 6, Pages: 9559-9562, ISSN: 2040-3364
Andresen H, Mager M, Griessner M, et al., 2014, Single-step homogeneous immunoassays utilizing epitope-tagged gold nanoparticles: on the mechanism, feasibility, and limitations, Chemistry of Materials, Vol: 26, Pages: 4696-4704, ISSN: 0897-4756
A single-step gold nanoparticle (AuNP)-based immunoassay is demonstrated in which the nanoparticle surface is tagged with short viral peptide epitopes. Antiviral antibodies with monoclonal specificity trigger nanoparticle aggregation yielding a colorimetric response that enables detection of antibodies in the low-nanomolar range within a few minutes. In silico insights into the interactions at the epitope–gold interface demonstrate that the conformational landscape exhibited by the epitopes is strongly influenced by the amino acid sequence and location of particular residues within the peptides. The conformation, orientation, and linker chemistry of the peptides affect the immune complex formation in nonintuitive ways that are, nevertheless, explained by a unique sterically kinetically driven aggregation mechanism. The rapid and specific performance of the AuNP immunoassay may have generic potential in point of care diagnostics and other laboratory routines.
Hedegaard MAB, Cloyd KL, Horejs C-M, et al., 2014, Model based variable selection as a tool to highlight biological differences in Raman spectra of cells, Analyst, Vol: 139, Pages: 4629-4633, ISSN: 0003-2654
Nair R, Santos L, Awasthi S, et al., 2014, Extracellular vesicles derived from preosteoblasts influence embryonic stem cell differentiation, Stem Cells and Development, Vol: 23, Pages: 1625-1635, ISSN: 1557-8534
Poologasundarampillai G, Yu B, Tsigkou O, et al., 2014, Poly(gamma-glutamic acid)/Silica Hybrids with Calcium Incorporated in the Silica Network by Use of a Calcium Alkoxide Precursor, Chemistry-A European Journal, Vol: 20, Pages: 8149-8160, ISSN: 1521-3765
Current materials used for bone regeneration are usually bioactive ceramics or glasses. Although they bond to bone, they are brittle. There is a need for new materials that can combine bioactivity with toughness and controlled biodegradation. Sol-gel hybrids have the potential to do this through their nanoscale interpenetrating networks (IPN) of inorganic and organic components. Poly(γ-glutamic acid) (γ-PGA) was introduced into the sol-gel process to produce a hybrid of γ-PGA and bioactive silica. Calcium is an important element for bone regeneration but calcium sources that are used traditionally in the sol-gel process, such as Ca salts, do not allow Ca incorporation into the silicate network during low-temperature processing. The hypothesis for this study was that using calcium methoxyethoxide (CME) as the Ca source would allow Ca incorporation into the silicate component of the hybrid at room temperature. The produced hybrids would have improved mechanical properties and controlled degradation compared with hybrids of calcium chloride (CaCl2), in which the Ca is not incorporated into the silicate network. Class II hybrids, with covalent bonds between the inorganic and organic species, were synthesised by using organosilane. Calcium incorporation in both the organic and inorganic IPNs of the hybrid was improved when CME was used. This was clearly observed by using FTIR and solid-state NMR spectroscopy, which showed ionic cross-linking of γ-PGA by Ca and a lower degree of condensation of the Si species compared with the hybrids made with CaCl2 as the Ca source. The ionic cross-linking of γ-PGA by Ca resulted in excellent compressive strength and reduced elastic modulus as measured by compressive testing and nanoindentation, respectively. All hybrids showed bioactivity as hydroxyapatite (HA) was formed after immersion in simulated body fluid (SBF).
Lin Y, Chapman R, Stevens MM, 2014, Label-free multimodal protease detection based on protein/perylene dye coassembly and enzyme-triggered disassembly, Analytical Chemistry, Vol: 86, Pages: 6410-6417, ISSN: 1086-4377
de la Rica R, Mendoza E, Chow LW, et al., 2014, Self-assembly of collagen building blocks guided by electric fields, Small, Vol: 10, Pages: 3876-3879, ISSN: 1613-6810
Show me the way: protein building blocks are programmed to assemble hierarchically and yield a defined fiber morphology of micrometric length and precise nanometric diameter. The key step of this method is to align the building blocks with an AC field prior to assembly. The resulting protein nanofibers are straightforwardly integrated with the circuitry for potential applications in bionanotechnology.
de la Rica R, Bat E, Herpoldt KL, et al., 2014, Nanoparticle growth via concentration gradients generated by enzyme nanopatterns, Advanced Functional Materials, Vol: 24, Pages: 3692-3698, ISSN: 1616-3028
Smith EL, Kanczler JM, Gothard D, et al., 2014, Dual growth factor-releasing hydrogels for enhancement of skeletal tissue repair within an ex vivo chick femur defect model, JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Vol: 8, Pages: 361-361, ISSN: 1932-6254
Poologasundarampillai G, Wang D, Li S, et al., 2014, Cotton-wool-like bioactive glasses for bone regeneration, Acta Biomaterialia, Vol: 10, Pages: 3733-3746, ISSN: 1742-7061
Inorganic sol–gel solutions were electrospun to produce the first bioactive three-dimensional (3-D) scaffolds for bone tissue regeneration with a structure like cotton-wool (or cotton candy). This flexible 3-D fibrous structure is ideal for packing into complex defects. It also has large inter-fiber spaces to promote vascularization, penetration of cells and transport of nutrients throughout the scaffold. The 3-D fibrous structure was obtained by electrospinning, where the applied electric field and the instabilities exert tremendous force on the spinning jet, which is required to be viscoelastic to prevent jet break up. Previously, polymer binding agents were used with inorganic solutions to produce electrospun composite two-dimensional fibermats, requiring calcination to remove the polymer. This study presents novel reaction and processing conditions for producing a viscoelastic inorganic sol–gel solution that results in fibers by the entanglement of the intermolecularly overlapped nanosilica species in the solution, eliminating the need for a binder. Three-dimensional cotton-wool-like structures were only produced when solutions containing calcium nitrate were used, suggesting that the charge of the Ca2+ ions had a significant effect. The resulting bioactive silica fibers had a narrow diameter range of 0.5–2 μm and were nanoporous. A hydroxycarbonate apatite layer was formed on the fibers within the first 12 h of soaking in simulated body fluid. MC3T3-E1 preosteoblast cells cultured on the fibers showed no adverse cytotoxic effect and they were observed to attach to and spread in the material.
Steele JAM, McCullen SD, Callanan A, et al., 2014, Combinatorial scaffold morphologies for zonal articular cartilage engineering, ACTA BIOMATERIALIA, Vol: 10, Pages: 2065-2075, ISSN: 1742-7061
Horejs C-M, Serio A, Purvis A, et al., 2014, Biologically-active laminin-111 fragment that modulates the epithelial-to-mesenchymal transition in embryonic stem cells, Proceedings of the National Academy of Sciences, Vol: 111, Pages: 5908-5913, ISSN: 1091-6490
The dynamic interplay between the extracellular matrix and embryonic stem cells (ESCs) constitutes one of the key steps in understanding stem cell differentiation in vitro. Here we report a biologically-active laminin-111 fragment generated by matrix metalloproteinase 2 (MMP2) processing, which is highly up-regulated during differentiation. We show that the β1-chain–derived fragment interacts via α3β1-integrins, thereby triggering the down-regulation of MMP2 in mouse and human ESCs. Additionally, the expression of MMP9 and E-cadherin is up-regulated in mouse ESCs—key players in the epithelial-to-mesenchymal transition. We also demonstrate that the fragment acts through the α3β1-integrin/extracellular matrix metalloproteinase inducer complex. This study reveals a previously unidentified role of laminin-111 in early stem cell differentiation that goes far beyond basement membrane assembly and a mechanism by which an MMP2-cleaved laminin fragment regulates the expression of E-cadherin, MMP2, and MMP9.
Basey-Fisher TH, Guerra N, Triulzi C, et al., 2014, Microwaving Blood as a Non-Destructive Technique for Haemoglobin Measurements on Microlitre Samples, ADVANCED HEALTHCARE MATERIALS, Vol: 3, Pages: 536-542, ISSN: 2192-2640
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