TY  - JOUR
AU  - Miletić, N.
AU  - Rohandi, R.
AU  - Vuković, Zorica
AU  - Nastasović, Aleksandra
AU  - Loos, K.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/600
AB  - Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m2/g), specific volumes (from 0.755 to 1.191 cm3/g) and particle sizes (<100 μm-630 μm) were synthesized via suspension polymerization. Modifications of poly(GMA-co-EGDMA) with various diamines (1,2-diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane and 1,8-diaminooctane), 2-fluoroethylamine, glutaraldehyde and cyanuric chloride were carried out. The influence of the interaction between Candida antarctica lipase B (Cal-B) and various carriers during immobilization on the loading and hydrolytic activity (hydrolysis of para-nitrophenyl acetate) of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30 °C and pH 6.8 was leading to increased activities. Purely physical adsorption between enzyme and copolymer was observed on carriers in which amine or fluorine groups were introduced into the carrier structure by modification with various diamines or 2-fluoroethylamine. As a consequence enzyme loading and activity decreases. In contrary, modification of the poly(GMA-co-EGDMA) with glutaraldehyde and cyanuric chloride results in a covalent connection between enzyme and carrier. The obtained results show a significant increase in Cal-B activity. The influence of the amount of glutaraldehyde and cyanuric chloride used for modification was screened. Increasing the amount of glutaraldehyde or cyanuric chloride used for modification resulted in an increase of the enzyme loading. Consequently, higher amount of glutaraldehyde used led to a higher fraction of the enzyme molecules that are covalently connected on to the carrier. As the amount of glutaraldehyde or cyanuric chloride used for modifications increases, activity of immobilized C. antarctica lipase B primarily increases, showing the highest value for 0.66% and 0.050% w/w, respectively, and subsequently decreases. We could show that Cal-B immobilized on epoxy-containing copolymer modified with glutaraldehyde and cyanuric chloride performs higher activity than free enzyme powder.
PB  - Elsevier
T2  - Reactive and Functional Polymers
T1  - Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization
VL  - 69
IS  - 1
SP  - 68
EP  - 75
DO  - 10.1016/j.reactfunctpolym.2008.11.001
ER  - 

@article{
author = "Miletić, N. and Rohandi, R. and Vuković, Zorica and Nastasović, Aleksandra and Loos, K.",
year = "2009",
abstract = "Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m2/g), specific volumes (from 0.755 to 1.191 cm3/g) and particle sizes (<100 μm-630 μm) were synthesized via suspension polymerization. Modifications of poly(GMA-co-EGDMA) with various diamines (1,2-diaminoethane, 1,4-diaminobutane, 1,6-diaminohexane and 1,8-diaminooctane), 2-fluoroethylamine, glutaraldehyde and cyanuric chloride were carried out. The influence of the interaction between Candida antarctica lipase B (Cal-B) and various carriers during immobilization on the loading and hydrolytic activity (hydrolysis of para-nitrophenyl acetate) of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30 °C and pH 6.8 was leading to increased activities. Purely physical adsorption between enzyme and copolymer was observed on carriers in which amine or fluorine groups were introduced into the carrier structure by modification with various diamines or 2-fluoroethylamine. As a consequence enzyme loading and activity decreases. In contrary, modification of the poly(GMA-co-EGDMA) with glutaraldehyde and cyanuric chloride results in a covalent connection between enzyme and carrier. The obtained results show a significant increase in Cal-B activity. The influence of the amount of glutaraldehyde and cyanuric chloride used for modification was screened. Increasing the amount of glutaraldehyde or cyanuric chloride used for modification resulted in an increase of the enzyme loading. Consequently, higher amount of glutaraldehyde used led to a higher fraction of the enzyme molecules that are covalently connected on to the carrier. As the amount of glutaraldehyde or cyanuric chloride used for modifications increases, activity of immobilized C. antarctica lipase B primarily increases, showing the highest value for 0.66% and 0.050% w/w, respectively, and subsequently decreases. We could show that Cal-B immobilized on epoxy-containing copolymer modified with glutaraldehyde and cyanuric chloride performs higher activity than free enzyme powder.",
publisher = "Elsevier",
journal = "Reactive and Functional Polymers",
title = "Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization",
volume = "69",
number = "1",
pages = "68-75",
doi = "10.1016/j.reactfunctpolym.2008.11.001"
}

Miletić, N., Rohandi, R., Vuković, Z., Nastasović, A.,& Loos, K.. (2009). Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization. in Reactive and Functional Polymers
Elsevier., 69(1), 68-75.
https://doi.org/10.1016/j.reactfunctpolym.2008.11.001

Miletić N, Rohandi R, Vuković Z, Nastasović A, Loos K. Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization. in Reactive and Functional Polymers. 2009;69(1):68-75.
doi:10.1016/j.reactfunctpolym.2008.11.001 .

Miletić, N., Rohandi, R., Vuković, Zorica, Nastasović, Aleksandra, Loos, K., "Surface modification of macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins for improved Candida antarctica lipase B immobilization" in Reactive and Functional Polymers, 69, no. 1 (2009):68-75,
https://doi.org/10.1016/j.reactfunctpolym.2008.11.001 . .

TY  - JOUR
AU  - Miletić, N.
AU  - Vuković, Zorica
AU  - Nastasović, Aleksandra
AU  - Loos, K.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/597
AB  - Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)s [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m2/g), specific volumes (from 0.755 to 1.191 cm3/g) and particle sizes (less than 100-650 μm) were synthesized via suspension polymerization. The influence of the resin properties on the loading of Candida antarctica lipase B (Cal-B) during immobilization and on the hydrolytic (hydrolysis of para-nitrophenyl acetate) and synthetic (ring-opening polymerization of ε-caprolactone) activity of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30 °C and pH 6.8 was leading to increased activities. By decreasing the resin diameter: (i) the amount of Cal-B adsorbed onto the resin decreases, (ii) the conversion of para-nitrophenyl acetate increases (hydrolytic activity) and (iii) the conversion of ε-caprolactone and the molecular weight of the synthesized poly-ε-caprolactone increases (synthetic activity). Varying the porosity parameters results in different hydrolytic and synthetic activities. Pore sizes of all synthesized resins (from 30 to 560 nm) are big enough to overcome diffusion limitations. Therefore increasing the pore size of the resins resulted in a large increase in the hydrolytic and synthetic activity. Increasing the specific surface area resulted in an increase of activities, as the result of alleviated substrate approach to the immobilized enzyme zones. The obtained results were compared to results from dried Cal-B powder and Novozyme 435. Resin with particle size less than 100 μm and pore size 48 nm had much higher hydrolytic activity than both dried Cal-B powder and Novozyme 435. Nearly similar trends were observed for the synthetic activity. Via the DMSO leaching technique we could show that about 80% of Cal-B was covalently attached to the macroporous resin.
PB  - Elsevier
T2  - Journal of Molecular Catalysis B: Enzymatic
T1  - Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts
VL  - 56
IS  - 4
SP  - 196
EP  - 201
DO  - 10.1016/j.molcatb.2008.04.012
ER  - 

@article{
author = "Miletić, N. and Vuković, Zorica and Nastasović, Aleksandra and Loos, K.",
year = "2009",
abstract = "Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)s [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m2/g), specific volumes (from 0.755 to 1.191 cm3/g) and particle sizes (less than 100-650 μm) were synthesized via suspension polymerization. The influence of the resin properties on the loading of Candida antarctica lipase B (Cal-B) during immobilization and on the hydrolytic (hydrolysis of para-nitrophenyl acetate) and synthetic (ring-opening polymerization of ε-caprolactone) activity of the immobilized Cal-B were studied. Immobilization of Cal-B was performed at different temperatures and pH values. Cal-B immobilized at 30 °C and pH 6.8 was leading to increased activities. By decreasing the resin diameter: (i) the amount of Cal-B adsorbed onto the resin decreases, (ii) the conversion of para-nitrophenyl acetate increases (hydrolytic activity) and (iii) the conversion of ε-caprolactone and the molecular weight of the synthesized poly-ε-caprolactone increases (synthetic activity). Varying the porosity parameters results in different hydrolytic and synthetic activities. Pore sizes of all synthesized resins (from 30 to 560 nm) are big enough to overcome diffusion limitations. Therefore increasing the pore size of the resins resulted in a large increase in the hydrolytic and synthetic activity. Increasing the specific surface area resulted in an increase of activities, as the result of alleviated substrate approach to the immobilized enzyme zones. The obtained results were compared to results from dried Cal-B powder and Novozyme 435. Resin with particle size less than 100 μm and pore size 48 nm had much higher hydrolytic activity than both dried Cal-B powder and Novozyme 435. Nearly similar trends were observed for the synthetic activity. Via the DMSO leaching technique we could show that about 80% of Cal-B was covalently attached to the macroporous resin.",
publisher = "Elsevier",
journal = "Journal of Molecular Catalysis B: Enzymatic",
title = "Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts",
volume = "56",
number = "4",
pages = "196-201",
doi = "10.1016/j.molcatb.2008.04.012"
}

Miletić, N., Vuković, Z., Nastasović, A.,& Loos, K.. (2009). Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts. in Journal of Molecular Catalysis B: Enzymatic
Elsevier., 56(4), 196-201.
https://doi.org/10.1016/j.molcatb.2008.04.012

Miletić N, Vuković Z, Nastasović A, Loos K. Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts. in Journal of Molecular Catalysis B: Enzymatic. 2009;56(4):196-201.
doi:10.1016/j.molcatb.2008.04.012 .

Miletić, N., Vuković, Zorica, Nastasović, Aleksandra, Loos, K., "Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts" in Journal of Molecular Catalysis B: Enzymatic, 56, no. 4 (2009):196-201,
https://doi.org/10.1016/j.molcatb.2008.04.012 . .