Use of a protease-modified-alumina complex to design a continuous stirred tank reactor for producing bioactive hydrolysates

Ticu, Elena-Loredana; Vercaigne-Marko, Dominique; Froidevaux, Rénato; Huma, Anca; Artenie, Vlad; Guillochon, Didier

doi:10.1016/j.procbio.2005.01.003

Cited by 23 publications

(13 citation statements)

References 22 publications

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“…It is worthwhile stressing that zero-order type release is the most satisfactory release strategy for drugreleasing implants, which results in the drug being released at a uniform and constant rate independent of concentration and time. 56 Considering that, increasing studies are focused on exploring different strategies in TNT-based drug-releasing implants in order to design and advance their drug-releasing performances for specific drugs and therapies. A schematic diagram summarizing these strategies aimed at controlling the release of drugs from TNTs is presented in Figure 2.…”

Section: Strategies To Control Drug Delivery From Tntsmentioning

confidence: 99%

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications

Wang¹,

Huang²,

Li³

et al. 2016

IJN

104

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Section: Strategies To Control Drug Delivery From Tntsmentioning

confidence: 99%

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications

Wang¹,

Huang²,

Li³

et al. 2016

IJN

104

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“…However, the higher K m value for the pepsin-silicone (A) compared to that of free pepsin indicates that the longer network precursor chain length, M n ∼26,000 g mol −1 disfavored the enzymesubstrate (ES) complex formation. Whereas the shorter precursor chain length in the pepsin-silicone (B), M n Temperature ( o C) 10 20 ∼750 g mol −1 was found to favor the ES complex formation resulting in a lower K m value.…”

Section: Kinetics Of the Hydrolysis Of Denatured Hemoglobin By Free Amentioning

confidence: 99%

“…No improvement in the activity with pH for the immobilized pepsin was observed [9]. Pepsin was immobilized on a modified alumina complex [10], a chemically modified poly(methyl methacrylate) (PMMA) [11], on an activated Sepharose 4B for affinity chromatography [12] and on agarose beads [13]. However, to our knowledge, studies on pepsin immobilized in silicone elastomers have not been reported in the literature to date, in spite of their being several advantages to utilizing silicone elastomers as a support material, as we will discuss herein.…”

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confidence: 98%

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Immobilization and Activity of Pepsin in Silicone Elastomers

Poojari

Palsule

Clarson

et al. 2009

Silicon

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Pepsin [EC, 3.4.23.1] from Porcine stomach mucosa was immobilized in silicone elastomers utilizing condensation-cure room temperature vulcanization (RTV) of silanol-terminated poly(dimethylsiloxane) (PDMS). Two network precursor chain molar masses were used in this investigation: in pepsin-silicone (A), M n ∼26,000 g mol −1 and in pepsin-silicone (B) M n ∼750 g mol −1 . Tetraethyl orthosilicate (TEOS) was used as the cross-linking agent and dibutyltin dilaurate was used as the catalyst. The activity and stability of free pepsin and pepsin immobilized in PDMS were studied with respect to pH, temperature, cross-link density, solvents and storage time using a hemoglobin assay. A notable finding is that free pepsin has zero activity in neutral buffer solution (pH 7) after incubation for 5 h, while pepsin immobilized in the silicone elastomers was found to retain more than 70% of its maximum normalized activity. There was no marked improvement in the thermal stability of the PDMS immobilized pepsin when compared to free pepsin and all the three systems showed no activity at and above 70°C. From the Lineweaver-Burk kinetic analyses, the apparent K m (g L −1 hemoglobin) for free pepsin was 4.5, for pepsinsilicone (A) was 5.1, and for pepsin-silicone (B) was 3.9, the V max (U/mg of pepsin) for free pepsin was 14,000, for pepsin-silicone (A) was 11,710, and for pepsin-silicone (B) was 8,510, respectively after incubation in buffer solution at pH 2 and 37°C. The activity of the free and the PDMS immobilized pepsin in six different organic solvents was also studied. The pepsin retained high activity in non-polar solvents such as n-hexane, isooctane and toluene, but the enzyme performed poorly in methanol, ethanol and tetrahydrofuran. The degree of swelling of the pepsin immobilized silicone elastomers in these solvents had no impact on the activity of the pepsin. When stored at room temperature for time periods up to 6 months, pepsin immobilized in silicone elastomers was observed to retain its full activity. The results reported herein demonstrate that cross-linked PDMS is a promising support material for the immobilization of hydrolytic enzymes such as pepsin.

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“…For example, Stigter et al (2008) described the use of pepsin microreactors consisting of pepsin immobilized in a fused-silica capillary. Pepsin was also immobilized on chitosan beads (Altun and Cetinus, 2007), acrylic copolymers with methacrylates as a co-monomer (Li et al, 2004;Shukla and Devi, 2005;Hu et al, 2006), a modified alumina complex (Ticu et al, 2005), agarose beads (Kurimoto et al, 2001), silica gels (Line et al, 1971), and cellulose-based carriers (Dumitriu et al, 1987). Most researchers focused their attention on one carrier (Hu et al, 2006) or a limited number of carriers but with the same basic structure (Poojari et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Novel Application of Porous and Cellular Materials for Covalent Immobilization of Pepsin

Szałapata

Osińska-Jaroszuk

Bryjak

et al. 2016

Braz. J. Chem. Eng.

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-Pepsin was immobilized via covalent bonds on different carriers: a silica gel carrier, acrylic beads, and a cellulose-based carrier -Granocel. All carriers were functionalized through the presence of -OH, -COOH, -NH 2 , or glycidyl groups on their surfaces. Three different cross-linkers were used for activation thereof. The results showed that Granocel activated by glutaraldehyde or carbodiimide and silica gel activated by glutaraldehyde were suitable carriers for the expression of enzyme activity. The optimum pH range for the native enzyme was 2.5-3.5 and this range was extended to the value 6.5 in the case of enzyme immobilized on the silica gel carrier and on Granocel. The optimum temperature values for the native and immobilized enzyme were in the range 37-40 °C and 40-50 °C, respectively. The activity of the immobilized pepsin at different values of pH and temperature was higher in comparison with the activity of the free enzyme.

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Use of a protease-modified-alumina complex to design a continuous stirred tank reactor for producing bioactive hydrolysates

Cited by 23 publications

References 22 publications

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications

Immobilization and Activity of Pepsin in Silicone Elastomers

Novel Application of Porous and Cellular Materials for Covalent Immobilization of Pepsin

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Use of a protease-modified-alumina complex to design a continuous stirred tank reactor for producing bioactive hydrolysates

Cited by 23 publications

References 22 publications

Recent advances on smart TiO<sub>2</sub>&nbsp;nanotube platforms for sustainable drug delivery applications

Recent advances on smart TiO<sub>2</sub>&nbsp;nanotube platforms for sustainable drug delivery applications

Immobilization and Activity of Pepsin in Silicone Elastomers

Novel Application of Porous and Cellular Materials for Covalent Immobilization of Pepsin

Contact Info

Product

Resources

About

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications

Recent advances on smart TiO<sub>2</sub> nanotube platforms for sustainable drug delivery applications