Polyelectrolytes for cell encapsulation

Bhatia, Surita R.; Khattak, Sarwat F.; Roberts, Susan C.

doi:10.1016/j.cocis.2005.05.004

Cited by 125 publications

(97 citation statements)

References 53 publications

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“…Many techniques for cell encapsulation have been reported, including interfacial polymerization [12] and solvent evaporation [7], sol-gel process [35], photolithography [28], ionic crosslinking [27]. In some cases, these techniques involve the prior formation of polymeric droplets in an oil-organic phase.…”

Section: Introductionmentioning

confidence: 99%

“…Eudragit coated microparticles were produced for the colonic release of therapeutics [16,18] or proteins [19], but it has not yet been applied for the coating of encapsulated cells. A variety of materials have been tested for the encapsulation of living cells; alginate [4,6,8,12,15,[20][21][22][23] is the most common and versatile, chitosan [9,23], gelatin [22,24], cellulose [23,25], agarose [23,26], dextran [1], carrageenan [9,12,27], poly(lactide-co-glycolide) (PLGA) [1,23], Poly (Ethylene Glycol) [23,28] all have been used individually, and in blends [1,27]. Chitosan is a proven biocompatible natural polymer produced from natural sources (crustacean shells, fungi, and insects), which has been widely used for cell encapsulation and other pharmaceutical purposes [23,29].…”

Section: Introductionmentioning

confidence: 99%

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Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification

Morelli

Holdich

Dragosavac

2017

Journal of Membrane Science

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Citation: MORELLI, S., HOLDICH, R. and DRAGOSAVAC, M., 2017. Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification. Journal of Membrane Science, 524, Additional Information:• This paper was accepted for publication in the journal Journal of This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. conditions. The liquid drops were loaded with increasing amount of yeast (3.14 x 10 7 to 3.14 x 10 8 cells/ mL). The stability and uniformity of the emulsions was independent of the cell concentration. PTFE coated hydrophobic membrane produced smaller W/O drops compared to FAS coated membranes. The liquid polymeric droplets were solidified in solid particles using thermal gelation and/or ionic crosslinking, obtaining yeast encapsulated particles sized ~100 µm.The pH sensitive polymer, Eudragit S100, was used as a coating to create gastro resistant particles suitable for intestinal-colonic targeted release. Viability of the released yeast cells was demonstrated using fluorescence probes and checking cell glucose metabolism with time. AbbreviationsW/O emulsion, water in oil

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification

Morelli

Holdich

Dragosavac

2017

Journal of Membrane Science

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“…Efficient micro-encapsulation of active ingredients, such as drugs, proteins, vitamins, flavours, gas bubbles, even living cells, is becoming increasingly important for a wide variety of applications from functional foods to drug delivery in biomedical applications [13][14][15][16]. Nano-and micro-encapsulation via LbL self-assembly has potential applications in biochemistry, pharmaceutics, controlled release, cosmetic, and catalyst [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Microcapsules for controlled release fabricated via layer-by-layer self-assembly of polyelectrolytes

Wang

Sun

et al. 2008

Journal of Experimental Nanoscience

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Layer-by-layer (LbL) self-assembly of oppositely charged polyelectrolytes on different templates by alternating deposition is a versatile method enabling the construction of ultrathin multilayer films with tunable thickness, composition, and functions. The principal driving force for the LbL self-assembly is dominantly the electrostatic attraction between the polyelectrolyte components accompanied with other associative interactions, such as hydrogen-bonding, hydrophobic interaction, charge-transfer and so on. The LbL self-assembly technique has been a powerful tool for micro/nano-encapsulation. Our strategy is to fabricate the nano-multilayer wall for micro-and sub-microcapsules by the LbL of polyelectrolytes, particularly natural polymers chitosan (CHI) and alginate (ALG) for drug controlled release. Our recent work following this strategy is reviewed in the present article. After determining the charge density threshold for the LbL assembly, we immobilised enzymes of urease and superoxide dismutase on polystyrene nanoparticles through the LbL and found the decrease in enzyme bioactivity but an increase in their storage stability. We successfully fabricated the nanocapsules from natural polysaccharides of CHI and ALG multilayers by the LbL for drug release. The LbL self-assembly of CHI and ALG was used directly on indomethacin (IDM) microcrystals to reduce the release rate. We observed that increasing deposition temperature would produce a more perfect multilayer film with higher thickness and reduced the release rate efficiently. Water soluble protein insulin was spontaneously loaded into the LbL CHI/ALG microcapsules due to the electrostatic attraction and a two-temperature loading procedure was suggested to increase the loading capacity and to reduce the release rate. The LbL multilayers have been used to encapsulate the drug-loading microparticles made from solvent evaporation or adsorption with porous CaCO 3 microparticles to enhance the loading capacity and suppress the initial burst. Increasing the layer number, raising the deposition temperature, and cross-linking the neighboring layers were confirmed to slow down the enzymatic desorption of polyelectrolyte multilayer films and the release rate of encapsulated drug effectively.

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“…In these systems, either acellular aqueous solutions of polymer or solutions containing desired cell type(s) are introduced at the tissue site. Subsequent gelation can occur by taking advantage of environmental differences between the polymeric solution and the in vivo environment such as temperature (14,15), ionic strength (16,17), or enzymatic activity (18). Alternatively, in vivo gelation can be accomplished by initiating the cross-linking of photopolymerizing polymer precursors by using cytocompatible photoinitiators (19,20).…”

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confidence: 99%

Controlling hydrogelation kinetics by peptide design for three-dimensional encapsulation and injectable delivery of cells

Haines-Butterick¹,

Rajagopal²,

Branco³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

608

739

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A peptide-based hydrogelation strategy has been developed that allows homogenous encapsulation and subsequent delivery of C3H10t1/2 mesenchymal stem cells. Structure-based peptide design afforded MAX8, a 20-residue peptide that folds and selfassembles in response to DMEM resulting in mechanically rigid hydrogels. The folding and self-assembly kinetics of MAX8 have been tuned so that when hydrogelation is triggered in the presence of cells, the cells become homogeneously impregnated within the gel. A unique characteristic of these gel-cell constructs is that when an appropriate shear stress is applied, the hydrogel will shear-thin resulting in a low-viscosity gel. However, after the application of shear has stopped, the gel quickly resets and recovers its initial mechanical rigidity in a near quantitative fashion. This property allows gel/cell constructs to be delivered via syringe with precision to target sites. Homogenous cellular distribution and cell viability are unaffected by the shear thinning process and gel/cell constructs stay fixed at the point of introduction, suggesting that these gels may be useful for the delivery of cells to target biological sites in tissue regeneration efforts.hydrogel ͉ self-assembly ͉ stem cell

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Polyelectrolytes for cell encapsulation

Cited by 125 publications

References 53 publications

Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification

Microparticles for cell encapsulation and colonic delivery produced by membrane emulsification

Microcapsules for controlled release fabricated via layer-by-layer self-assembly of polyelectrolytes

Controlling hydrogelation kinetics by peptide design for three-dimensional encapsulation and injectable delivery of cells

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