Novel porous starch/ alginate hydrogel for controlled insulin release with dual response of pH and amylase

2017 ◽

Vol 4 (1) ◽

pp. 28-35

Author(s):

Siti Sabrina Mohd Sukri ◽

Mimi Sakinah A.M

Keyword(s):

Sodium Alginate ◽

Covalent Binding ◽

Xylanase Activity ◽

Alginate Hydrogel ◽

Hydrogel Beads ◽

Alginate Concentration ◽

Xylanase Enzyme ◽

Acid Reagent ◽

Support Matrix ◽

Harsh Conditions

Enzymes serving as biocatalysts and play an important roles in many industrial field. However, the limitation of enzyme usage due to its high cost and unstable conditions of soluble enzyme to harsh conditions lead to findings an alternative to enhance the enzyme efficiency by immobilisation (insoluble enzyme). The present work reported a combination of immobilisation technique of xylanase by entrapment and covalent binding on alginate hydrogel beads. Xylanase enzyme was effectively immobilised within the support matrix, alginate hydrogel beads by entrapment and covalent binding on the surface of beads using glutaraldehyde as a cross-linked agent. The effects of support matrix comprised of sodium alginate concentration (% w/v) and calcium chloride, CaCl2 (M) were studied in order to obtain a better immobilisation yield. The suitable concentration of sodium alginate and CaCl2 to ensure a robust and stable hydrogel beads with higher immobilisation yield were formed as a support matrix for xylanase immobilisation. The analysis of xylanase activity was determined using dinitrosalicyclic (DNS) acid reagent method. Maximal enzyme immobilisation yield (>80 %) was achieved at 3.0 % w/v of sodium alginate concentration and 0.3 M of CaCl2. The study shows the support matrix of hydrogel beads gave a significant impact towards the immobilisation yield of xylanase.

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Insulin release from alginate microspheres reinforced with dextran sulfate

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq0601040s ◽

2006 ◽

Vol 12 (1) ◽

pp. 40-46 ◽

Cited By ~ 5

Author(s):

Catarina Silva ◽

António Ribeiro ◽

Francisco Veiga ◽

Adriano Sousa

Keyword(s):

Insulin Release ◽

Encapsulation Efficiency ◽

Dextran Sulfate ◽

Low Ph ◽

Gastric Ph ◽

Release Profile ◽

Internal Gelation ◽

High Insulin ◽

Harsh Conditions ◽

Alginate Matrix

In a previous study, insulin was efficiently encapsulated in alginate microspheres using an emulsification/internal gelation process. However these microspheres showed a high insulin release at gastric pH, exposing the protein to the harsh conditions of the stomach. In this study, our attempt was to improve insulin release profile by reinforcing the alginate matrix with dextran sulfate (DS). The size distribution was not altered by the presence of DS and the encapsulation efficiency increased to 100%. DS was also able to prevent insulin release at pH 1.2, protecting the insulin from an acidic environment. This effect was explained by an interaction between the permanent negatively charged groups of DS and insulin at low pH. When reinforced alginate microspheres were transferred to neutral pH, dissolution occurred within a few minutes. Increase of the adjuvant concentration did not improve the insulin release profile.

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Glucose-Triggered Insulin Release from Fe3+ -Cross-linked Alginate Hydrogel: Experimental Study and Theoretical Modeling

ChemPhysChem ◽

10.1002/cphc.201700195 ◽

2017 ◽

Vol 18 (12) ◽

pp. 1541-1551 ◽

Cited By ~ 8

Author(s):

Sabrina Scheja ◽

Sergii Domanskyi ◽

Maria Gamella ◽

Kelly L. Wormwood ◽

Costel C. Darie ◽

...

Keyword(s):

Experimental Study ◽

Insulin Release ◽

Theoretical Modeling ◽

Alginate Hydrogel

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W09.265 Effects of fish oil on glucoregulation and insulin release in hereditary hypertriglyceridemic rats

Atherosclerosis ◽

10.1016/s0021-9150(04)90264-x ◽

2004 ◽

Vol 5 (1) ◽

pp. 62

Author(s):

A ZAK

Keyword(s):

Fish Oil ◽

Insulin Release

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THE EFFECT OF FASTING AND SELECTIVE RE-FEEDING ON INSULIN RELEASE IN THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.0720046 ◽

1973 ◽

Vol 72 (1) ◽

pp. 46-53 ◽

Cited By ~ 9

Author(s):

D. S. Turner ◽

D. A. B. Young

Keyword(s):

Insulin Release ◽

Acute Effect ◽

Secretory Response ◽

Release Mechanism ◽

Β Cell ◽

Intestinal Hormones ◽

Intravenous Glucose ◽

Glucose Ingestion ◽

Glucose Test ◽

Insulin Secretory Response

ABSTRACT The insulin secretory response in the rat to intravenous glucose was found to be greatly impaired by fasting for three days, whereas that to orally administered glucose was not significantly affected. Rats fasted for two days were given either protein or starch pellets for six hours, and then fasted for a further eighteen hours before the intravenous glucose test. The protein pre-feeding failed to affect significantly the subsequent insulin secretory response to intravenous glucose, whereas starch prefeeding greatly enhanced it. It is suggested that intestinal hormones released by glucose ingestion may exert not only an acute effect on insulin release, but also a 'priming' effect on the insulin release mechanism of the β cell, which enables it to respond to the subsequent stimulus of glucose alone.

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PROTEIN SYNTHESIS AND INSULIN RELEASE IN MICRODISSECTED ISLETS OF STEROID DIABETIC MICE

Acta Endocrinologica ◽

10.1530/acta.0.080s039 ◽

1975 ◽

Vol 80 (1_Suppla) ◽

pp. S39

Author(s):

K.-G. Petersen ◽

B. Kröncke

Keyword(s):

Protein Synthesis ◽

Insulin Release ◽

Diabetic Mice

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Insulin release and pancreatic insulin is reduced in young prediabetic BB rats

Acta Endocrinologica ◽

10.1530/acta.0.1120367 ◽

1986 ◽

Vol 112 (3) ◽

pp. 367-371 ◽

Cited By ~ 16

Author(s):

Annette Svenningsen ◽

Thomas Dyrberg ◽

Helle Markholst ◽

Christian Binder ◽

Åke Lernmark

Keyword(s):

Insulin Release ◽

Insulin Dependent Diabetes Mellitus ◽

Insulin Content ◽

Dependent Diabetes Mellitus ◽

Clinical Onset ◽

Pancreatic Insulin ◽

Pancreatic Insulin Content ◽

Bb Rats ◽

Insulin Dependent ◽

The Mean

Abstract. The pancreases of approximately 50 days old diabetes-prone BB/Hagedorn (BB/H) and of the genetically closely related, but non-diabetic BB w-subline (control BB) rats were perfused to determine the capacity of D-glucose to release insulin before the expected development of diabetes. The BB/H rats were from a colony with 82–84% incidence of insulin-dependent diabetes mellitus (IDDM) by 140 days of age. The total amount of insulin released from the BB/H rat pancreas during stimulation with 20 mmol/l D-glucose was reduced by nearly 50% (P <0.01). The initial peak of insulin release was similar between the two groups of animals, whereas the amount of insulin released during the second peak accounted for the diminished release (P < 0.01). The extractable pancreatic insulin was 30% (P < 0.05) less in the BB/H rats. Total insulin release expressed relative to the pancreatic insulin content, was therefore not different between the two groups. It is concluded that about 20–40 days before the mean age of clinical onset of IDDM in BB/H rats, the capacity to release insulin in response to D-glucose is reduced along with a diminished pancreatic insulin content. This abnormality seems to be preceded only by islet cell surface antibodies but not by insulitis.

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