Effect of alginate-polylysine-alginate microencapsulation on in vitro insulin release from rat pancreatic islets

Fritschy, Wilbert M.; Wolters, G. H. J.; Schilfgaarde, R. van

doi:10.2337/diabetes.40.1.37

Cited by 55 publications

(41 citation statements)

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“…A more recent study by de Haan et al concluded that it was the porosity of the alginate/ poly-L-lysine (PLL) matrix, i.e., the time that alginate was allowed to interact with PLL, that was critical to insulin release, while capsule diameter (for capsules up to 800 lm in diameter) did not affect insulin release (de Haan et al 2003). Although these and other reports (Fritschy et al 1991;van Schilfgaarde and de Vos 1999;Lembert et al 2001;Rasmussen et al 2003) describe the effects of alginate encapsulation on the quantity of insulin released over a period of time, they do not detail the effects of encapsulation on the precise dynamics of insulin secretion in response to physiologic stimuli. Reported results indicate that, when properly designed, encapsulated cell systems exhibit the same secretory dynamics shortly post-encapsulation as do free, suspended cells .…”

Section: Introductionmentioning

confidence: 94%

Insulin secretion dynamics of free and alginate-encapsulated insulinoma cells

2006

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This study investigates the effect of alginate/poly-L: -lysine/alginate (APA) encapsulation on the insulin secretion dynamics exhibited by an encapsulated cell system. Experiments were performed with the aid of a home-built perfusion apparatus providing a 1 min temporal resolution. Insulin profiles were measured from: (i) murine insulinoma betaTC3 cells encapsulated in calcium alginate/poly-L: -lysine/alginate (APA) beads generated with high guluronic (G) or high mannuoric (M) content alginate, and (ii) murine insulinoma betaTC-tet cells encapsulated in high M APA beads and propagated in the presence and absence of tetracycline. Results show that encapsulation in APA beads did not affect the insulin secretion profile shortly post-encapsulation. However, remodeling of the beads due to cell proliferation affected the insulin secretion profiles; and inhibiting remodeling by suppressing cell growth preserved the secretion profile. The implications of these findings regarding the in vivo function of encapsulated insulin secreting cells are discussed.

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Section: Introductionmentioning

confidence: 94%

Insulin secretion dynamics of free and alginate-encapsulated insulinoma cells

2006

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“…Because of the strong application potential, such as the encapsulation of drugs (Mishra and Pandit 1989;Ferreira et al 1994) and living cells (Lim and Sun 1980;Fritschy et al 1991;Dusseault et al 2005), considerable attention has been attracted to the development of controllable and reliable fabrication schemes for double emulsions. Recently, researchers have demonstrated double emulsification in various microfluidic devices utilizing two-step breakup (Seo et al 2007;Okushima et al 2004;Lao et al 2009) and three-dimensional (3D) flow focusing (Berkland et al 2004;Bocanegra et al 2005;Utada et al 2005;Huang et al 2006;Chang and Su 2008).…”

Section: Introductionmentioning

confidence: 99%

On-demand double emulsification utilizing pneumatically actuated, selectively surface-modified PDMS micro-devices

Lin

Chang

2010

Microfluid Nanofluid

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This article presents an active, two-step emulsification scheme that is capable of producing double emulsions with desired geometries and compositions on demand. Three-layer PDMS micro-devices with pneumatically actuated membrane-valves constructed on top of specially designed fluidic-channels are utilized to meter and shape immiscible fluids into double emulsions. By intermittently squeezing a fluid into another one, controlled emulsification is realized, and successive emulsification steps result in the formation of multiple emulsions. In the prototype demonstration, a three-layer PDMS molding and bonding process was employed to fabricate the proposed microfluidic devices, whose channel surfaces were selectively modified into hydrophilic by a photo-grafting process. A governing computer program cooperating with a set of control hardware was employed to coordinate the actuation of the prototype system. It has been demonstrated that: (1) both water-in-oil-in-oil and water-in-oil-in-water double emulsions can be produced; (2) the sizes of inner aqueous droplets and outer oil drops can be controlled independently; and (3) adjacent oil drops with varying overall sizes, and both diameters and numbers of inner aqueous droplets can be produced on demand. As such, the demonstrated emulsification scheme could potentially fulfill the real-time controllability on emulsion formation, which is desired for a variety of chemical and biological applications.

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“…Because of the strong application potential, such as the encapsulation of drugs (Mishra and Pandit 1989;Ferreira et al 1994) and living cells (Lim and Sun 1980;Fritschy et al 1991;Dusseault et al 2005), considerable attention has been attracted to the development of controllable and reliable doubleemulsification schemes. Recently, researchers have demonstrated double-emulsification in various microfluidic devices utilizing two-step breakup (Okushima et al 2004;Seo et al 2007;Lao et al 2009) and 3D flow focusing (Berkland et al 2004;Bocanegra et al 2005;Utada et al 2005;Huang et al 2006;Chang and Su 2008).…”

Section: Introductionmentioning

confidence: 99%

On-demand micro-encapsulation utilizing on-chip synthesis of semi-permeable alginate-PLL capsules

Chang

2010

Microfluid Nanofluid

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This article presents an on-demand, multi-step synthesis scheme that is capable of forming semi-permeable micro-capsules on an integrated microfluidic system. Emulsion droplets functioning as templates and reactors are employed to realize the synthesis process. Threelayered PDMS micro-devices with pneumatically actuated diaphragm valves constructed on top of specially designed fluidic-channels are utilized to control the droplets and, consequently, the encapsulation process. A PDMS molding and bonding process is used to fabricate the proposed microfluidic devices. In the prototype demonstration, relatively small Na-alginate droplets are metered, trapped, and then drawn into relatively large CaCl 2 droplets, while they react and form solid Ca-alginate micro-capsules on the interfaces. In addition, entrapment and transfer of the resulting capsules can also be performed on the same microfluidic system to further process Ca-alginate into semi-permeable alginate-poly-L-lysine (PLL). It has been demonstrated that: (1) both emulsion droplets and solid capsules could be manipulated; (2) multi-step reactions could be performed on droplet-in-droplet interfaces to synthesize alginate-PLL capsules; and (3) on demand, controlled encapsulation could be achieved on an integrated microfluidic system. As such, the demonstrated multi-step synthesis scheme could potentially fulfill the real-time controllability on micro-encapsulation, which is desired for a variety of biological and medical applications.

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Effect of alginate-polylysine-alginate microencapsulation on in vitro insulin release from rat pancreatic islets

Cited by 55 publications

References 0 publications

Insulin secretion dynamics of free and alginate-encapsulated insulinoma cells

Insulin secretion dynamics of free and alginate-encapsulated insulinoma cells

On-demand double emulsification utilizing pneumatically actuated, selectively surface-modified PDMS micro-devices

On-demand micro-encapsulation utilizing on-chip synthesis of semi-permeable alginate-PLL capsules

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