How to build an adapted and bioactive cell microenvironment? A chemical interaction study of the structure of Ca‐alginate matrices and their repercussion on confined cells

Bienaimé, Christophe; Barbotin, Jean‐Noël; Nava-Saucedo, José-Edmundo

doi:10.1002/jbm.a.10487

Cited by 40 publications

(45 citation statements)

References 22 publications

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“…Calcium alginate gels are prepared usually in the form of beads. There are many reports about the experimental details in order to optimize both the bead structure and the bead formation process (Liu et al 2002;Najafpour et al 2004;Chai et al 2004;Bienaimé et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Studies of the mechanical properties and the fermentation behavior of double layer alginate–chitosan beads, using Saccharomyces cerevisiae entrapped cells

Liouni

Drichoutis

Nerantzis

2007

World J Microbiol Biotechnol

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Double layer alginate beads coated with chitosan were constructed for the entrapment of yeast cells used in alcoholic fermentations. Several construction parameters of the beads were studied. Among these parameters were the composition of the inner and the outer layer, the initial cell loading, the concentration of chitosan in the coating solution. Improved bead behavior was noticed by the use of chitosan as a coating agent to double layer alginate beads. The mechanical strength and the stability of the beads were enhanced. The polyelectrolyte complex membrane of alginate-chitosan reduced significantly the leakage of the entrapped cells into the medium. The aim of this work was to define the optimal conditions for the construction of the double layer alginate beads coated with chitosan with the purpose of using them for the fermentation of carbohydrates.

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Section: Introductionmentioning

confidence: 99%

Studies of the mechanical properties and the fermentation behavior of double layer alginate–chitosan beads, using Saccharomyces cerevisiae entrapped cells

Liouni

Drichoutis

Nerantzis

2007

World J Microbiol Biotechnol

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“…This suspension is then compartmentalized into single small droplets by one of several available techniques (13)(14)(15). Next, the droplets are reinforced by gelation, which in the case of agaroses is induced by cooling (16) and in the case of alginates by chemically induced cross linking (17,18). As a result, cells become immobilized within the microcarrier.…”

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confidence: 99%

Isolation of monoclonal microcarriers colonized by fluorescent E. coli

et al. 2008

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Microencapsulation gains increasing importance for processing of bacterial libraries and especially in high-throughput (HT) environments where [10 6 samples per day are studied. As a rule, a one-to-one relationship between an individual cell and analytical results is of key importance. Ideally, each microcarrier would therefore contain exactly one cell or colony. However, synthesis of larger numbers of capsules containing exactly one cell is not feasible as cells are randomly distributed during carrier-production. The dilemma is that high dilution conditions will yield a satisfactory degree of monoclonality, but also a very large fraction of empty compartments, whereas distribution under low dilution generates unacceptable numbers of polyclonal compartments for whose removal no satisfactory technologies exist. Hydrogel carriers with a volume of 35 nL were used as growth compartments for individual microbial colonies. E. coli cells expressing green fluorescent protein (GFP) were encapsulated at low dilution thereby intentionally producing a considerable amount of polyclonal microcarrieres. Empty and polyclonal microcarriers were then removed from the desired monoclonal fraction by a COPAS Plus particle analyzer. The results were compared with model predictions in order to investigate possible limitations in the analysis and sorting of monoclonal microcarriers by COPAS. Fluorescent E. coli cells (GFP) distributed randomly throughout the microcarrier population. Cells were successfully propagated to colonies in the microcarriers and enriched to 95% monoclonality by a COAPS sorter. Enrichment-efficiency was found to mainly depend on the colony diameter. With increasing colony size two contrary effects were observed: First, improved sorting efficiency due to increased fluorescence intensity and therefore higher detection efficiency, and second, deterioration of sorting efficiency due to occlusion occurring in polyclonal carriers. The combination of microencapsulation under low dilution conditions followed by HT sorting procedures is an efficient way for isolating larger amount of monoclonal carriers from bacterial libraries while concomitantly keeping the amounts of empty carriers at a moderate level. ' International Society for Advancement of CytometryKey terms microencapsulation; monoclonality; microcarrier; in vitro compartmentalization (IVC); fluorescent E. coli; COPAS plus particle analyzer and sorter; ultrahigh throughput screening THE enormous complexity of living systems makes high-throughput (HT) experimenting and analyses an indispensable tool for research and development in the lifeand biosciences. Sample numbers exceeding 10 6 per day (1-4) require new technologies for sample miniaturization and highly parallelized processing (5). Naturally, most experimental strategies rely on formation of spatially separated monoclonal cell assemblies at the beginning. If microbial species are studied, an approach that is frequently employed for generating larger numbers of monoseptic compartments is to first ...

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“…The extrusion process was only used for alginate bead generation by so-called external gelation in calcium chloride solution, yielding immobilizates with a less dense polymer structure in the bead core. 20 Bead sizes were limited by the nozzle size, the rotational speed of the JetCutting V R tool beneath the nozzle, and the extrusion pressure. Additionally, addition of magnetite to the initial polymer solution quickly caused the inline filters of the JetCutter V R system to be plugged.…”

Section: Resultsmentioning

confidence: 99%

Influence of different magnetites on properties of magnetic Pseudomonas aeruginosa immobilizates used for biosurfactant production

Heyd¹,

Weigold²,

Franzreb³

et al. 2009

Biotechnology Progress

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During the last decades, whole-cell immobilization has been used successfully in many bioprocesses. In particular, it is aimed at implementing continuous production processes, reaching higher production rates, and reusing the biocatalyst. In some cases, effective retention of immobilizates in the bioprocess is not feasible by membranes or sieves due to pore plugging or undesired losses of immobilizates. In the present publication, it is reported about the investigation of magnetic immobilizates of Pseudomonas aeruginosa for application in continuous biosurfactant production of rhamnolipids by foam fractionation and retention of entrained immobilizates by high-gradient magnetic separation from foam. Different materials and methods were tested with respect to important parameters, such as stability, diffusion properties or magnetic separation. Good magnetic separation of immobilizates was achieved at 5% (w/w) magnetite loading. Best results in terms of homogeneous embedding, good diffusion properties, and stability enhancement vis-à-vis pure alginate beads was achieved with alginate beads with embedded Bayoxide magnetite or MagPrep silica particles. Although polyurethane immobilizates showed higher stabilities compared with alginate beads, rhamnolipid diffusion in immobilizates was superior in magnetic alginate beads. Regarding bead production, smaller immobilizates were achieved with suspension polymerization compared to droplet extrusion by the JetCutting technology. In total, magnetic immobilizates are a promising tool for an easier handling of biocatalysts in a continuous biological production process, but they have to be adapted to the current production task.

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How to build an adapted and bioactive cell microenvironment? A chemical interaction study of the structure of Ca‐alginate matrices and their repercussion on confined cells

Cited by 40 publications

References 22 publications

Studies of the mechanical properties and the fermentation behavior of double layer alginate–chitosan beads, using Saccharomyces cerevisiae entrapped cells

Studies of the mechanical properties and the fermentation behavior of double layer alginate–chitosan beads, using Saccharomyces cerevisiae entrapped cells

Isolation of monoclonal microcarriers colonized by fluorescent E. coli

Influence of different magnetites on properties of magnetic Pseudomonas aeruginosa immobilizates used for biosurfactant production

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