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Coradin, Thibaud; Mercey, Emilie; Lisnard, Laurent; Livage, Jacques

doi:10.1039/b108324b

Cited by 101 publications

(83 citation statements)

References 10 publications

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“…29 Another strategy relies on the pre-immobilization of the cells within Ca 2+ -cross-linked alginate beads followed by reinforcement either by embedding the Ca-alginate beads within thick silica gel bodies 25,30,31 or by silica layer deposition at the bead surface. 32,33 When silica is deposited onto alginate, it is important to note that silica and alginate are both negatively charged at neutral pH; only weak hydrogen bonds may arise between the two components. 24 To strengthen the interface between alginate and silica, Coradin et al 32 deposited an intermediate layer of polycations (e.g., poly-L-lysine) on the Ca-alginate bead surface, resulting in a net positive charge favouring silica condensation at the surface of the Ca-alginate matrix.…”

Section: 28mentioning

confidence: 99%

“…32,33 When silica is deposited onto alginate, it is important to note that silica and alginate are both negatively charged at neutral pH; only weak hydrogen bonds may arise between the two components. 24 To strengthen the interface between alginate and silica, Coradin et al 32 deposited an intermediate layer of polycations (e.g., poly-L-lysine) on the Ca-alginate bead surface, resulting in a net positive charge favouring silica condensation at the surface of the Ca-alginate matrix. Sakai et al 33 further improved the silica layer deposition by using an amino-functionalized silica alkoxide: aminopropyl-trimethoxysilane.…”

Section: 28mentioning

confidence: 99%

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Alginate/silica hybrid materials for immobilization of green microalgae Chlorella vulgaris for cell-based sensor arrays

Pannier

Soltmann

et al. 2014

J. Mater. Chem. B

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Thin layers and patterned dot arrays of sodium alginate containing living microalgal cells were deposited onto glass carriers which were subsequently gelled using amino-functionalized silica sol to obtain reinforced alginate hydrogels. The resulting alginate/silica hybrid materials showed improved stability in salt-containing solutions compared to alginate gels gelled by traditional methods using Ca 2+ -ions. Cell arrays were patterned by printing nanolitre-scale drops of sodium alginate/cell suspension using a noncontact micro-dosage system which allows the printing of solutions of high viscosity. Cultures of the green microalga Chlorella vulgaris were immobilized within the newly developed alginate/silica hydrogels in order to demonstrate the potential of the hybrid matrix for the design of cell-based detection systems. The herbicide atrazine as well as copper ions have been used as model toxicants.Short-term toxicity tests (exposure time: 1 h) have been carried out using atrazine and changes in chlorophyll a (Chl a) fluorescence were measured by imaging pulse amplitude modulated-fluorometry (Imaging-PAM). C. vulgaris cells immobilized within alginate/silica hydrogels demonstrated a highly reproducible response pattern and compared well to freely suspended cells. Activity and response sensitivity of immobilized cells to atrazine was largely maintained for up to 8 weeks, especially when stored under cool conditions in the dark. Furthermore, immobilized cells could be repeatingly used for short-term toxicity tests as atrazine produces a reversible inhibition of photosynthesis.

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Section: 28mentioning

confidence: 99%

Section: 28mentioning

confidence: 99%

Alginate/silica hybrid materials for immobilization of green microalgae Chlorella vulgaris for cell-based sensor arrays

Pannier

Soltmann

et al. 2014

J. Mater. Chem. B

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“…3 Moreover, according to recent studies, alginate-silica biocomposite can be used for enzyme and cell immobilization. 4 Chitosan (CSI) [poly-b(1,4)-2-amino-2-deoxy-D-glucose] is a partially deacetylated derivative of chitin, a natural polymer found in the cell wall of fungi, microorganisms, and in mollusk shells, is believed to play an important role in controlling the mineralization process, in vivo. 5 The mineralization process mainly occurs through the following steps: (1) the biopolymer matrix forms a mineralization framework, where metallic ions are entrapped and associated through electrostatic interaction with soluble proteins/polysaccharides and adopts its shape; (2) subsequently, an oriented nuclei form across and the crystallization propagates from the surface of the matrix, resulting in the formation of a single crystal with controlled orientation and predetermined microstructure.…”

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of novel hybrid of bio‐assisted mineralized Zn‐Al layered double hydroxides using chitosan as a template

Depan

Singh

2009

J of Applied Polymer Sci

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The purpose of this study was to prepare and characterize a novel nanohybrid prepared from the template-assisted mineralization of Zn-Al Layered Double Hydroxide (LDH) onto the surface of Chitosan (CSI), with an emphasis on morphology, biocompatibility, and its use as an efficient drug carrier agent. The as prepared LDH is highly crystalline, with platelet-like morphology and curved tactoids when nucleated onto the surface of CSI. Our results indicate that the AOH and ANH functional moieties on CSI can direct an ordered structure of LDH, due to the electrostatic interaction between biopolymer and inorganic lamellae. We have been successful to intercalate an antiinflammatory drug, Sodium Ibuprofen (Ibu), into LDH, through conventional coprecipitation method. LDHs are endowed with great potential for delivery vector because their stacked layers lead to safe reservation of biofunctional molecules or genes, and their ion exchangeability and solubility in acidic media (pH < 4) give rise to the controlled release of drug molecules. According to the cell-growth studies, LDHs are found as cell viable up to the concentration of 500 lg/mL. This study reveals that LDH not only plays a role of a biocompatible-delivery matrix but also facilitates a significant increase in the delivery efficiency.

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“…Their formation by a complex process with a different mechanism is reported elsewhere. [16] The resulting silica nanocapsules could offer some advantages over organic polymer coatings such as improved mechanical strength, chemical stability, and biocompatibility for various potential biotechnological applications. The positively charged gelatin can interact electrostatically with negatively charged polysaccharides such as arabic gum in mildly acidic solution (~pH 5.0), and their solubilities are accordingly sharply reduced.…”

mentioning

confidence: 99%

“…The changes in the interfacial tension are capable of generating enough electrocapillary pressure to transport fluids. [14] Since the control electrodes are insulated from the liquid, the electrocapillarybased pumping system provides many advantages over traditional electrokinetic pumping systems, [15,16] including the prevention of ohmic heating and undesired electrochemical reactions, which are very important when dealing with delicate biological samples. It has been demonstrated that the electrocapillary effect can be used to actively move microand nanoparticles in microfluidic networks.…”

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confidence: 99%

Nanometer‐Sized Gold‐Loaded Gelatin/Silica Nanocapsules

2005

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Gelatin is the thermally and hydrolytically denatured product of collagen, the most abundant protein in animals, and, further, it has been utilized extensively for industrial, pharmaceutical, and medical applications. [1,2] At elevated temperature, gelatin exists predominantly in the form of flexible, unfolded coils in solution and can be partially renatured to the ordered, collagen-like helixes upon cooling to room temperature.[1±3] Intensive research has been done on the intricate folding of collagen from random coils to its conformation in the biologically active form. Yet, surprisingly little attention has been paid to the unfolded state, although the insight is emerging that the prevailing dogma may be wrong in depriving unfolded proteins of any biological importance. [4,5] Herein, the electrostatic-force-driven self-assembling behavior of acid-processed gelatin polypeptides has been investigated through the predominantly seeded aggregation growth of denatured gelatin chains, which are selectively adsorbed on citrate-stabilized gold nanoparticles. After mechanical stabilization with a thin layer of silica, the resulting nanometer-sized gold-loaded silica nanocapsules can be directly used for studying the structure and morphology of self-assembled nanoaggregates of gelatin using functional gold nanoparticles as optical and electronic probes. The bifunctional gelatin±silica nanocapsules filled with gold nanoparticles may be further functionalized with biomolecules using well-established silica surface chemistry and, in addition, substances can be encapsulated in the swollen gelatin nano-aggregates for potential bioimaging, diagnostics, drug delivery, etc. This synthetic approach has also been extended to various silica-coated biomolecules, such as polysaccharides and, in addition, it provides insight for creating novel smart bionanostructures. As observed in Figure 1A, well-dispersed gelatin-stabilized gold nanoparticles were prepared using a synthetic procedure described in the Experimental section. Interestingly, the additional silica coating of gelatin-stabilized gold nanoparticles can create novel nanometer-sized gold-loaded silica nanocapsules instead of silica-coated gold nanoparticles, as shown in Figure 1B. All the resulting silica nanocapsules have a uniform silica shell~10 nm in thickness, and the resulting large cavity~40 nm in diameter is filled with swollen gelatin in water, as indicated by the random distribution of the gold nanoparticles (different locations and positions) in the interior of the nanocapsules and by their distinct absorption properties. The cavity volume of a nanocapsule is ca. 18 times larger than the volume of a gold nanoparticle. When citrate-stabi- . Transmission electron microscopy (TEM) images of A) gelatinstabilized gold nanoparticles, and B) silica-coated, gelatin-stabilized gold nanoparticles (nanometer-sized gold-loaded gelatin/silica nanocapsules); C) UV-vis absorption spectra of a) citrate-stabilized gold nanoparticles, b) gelatin-stabilized gold nanoparticles, c) si...

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Abstract: Alginate-based microcapsules are coated with silica, providing enhanced mechanical resistance, protein diffusion and allowing enzyme immobilization.

Cited by 101 publications

References 10 publications

Alginate/silica hybrid materials for immobilization of green microalgae Chlorella vulgaris for cell-based sensor arrays

Alginate/silica hybrid materials for immobilization of green microalgae Chlorella vulgaris for cell-based sensor arrays

Preparation and characterization of novel hybrid of bio‐assisted mineralized Zn‐Al layered double hydroxides using chitosan as a template

Nanometer‐Sized Gold‐Loaded Gelatin/Silica Nanocapsules

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