Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 2837-2848 |
| Number of pages | 12 |
| Journal | Cellulose |
| Volume | 24 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 1 Jul 2017 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- antibacterial aerogel
- cellulose nanofibrils (CNF)
- enzyme stability
- lysozyme
- silver nanoparticles
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Retention of lysozyme activity by physical immobilization in nanocellulose aerogels and antibacterial effects. / Uddin, Khan; Orelma, Hannes; Mohammadi, Pezhman; Borghei, Maryam; Laine, Janne; Linder, Markus; Rojas, Orlando.
In: Cellulose, Vol. 24, No. 7, 01.07.2017, p. 2837-2848.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Retention of lysozyme activity by physical immobilization in nanocellulose aerogels and antibacterial effects
AU - Uddin, Khan
AU - Orelma, Hannes
AU - Mohammadi, Pezhman
AU - Borghei, Maryam
AU - Laine, Janne
AU - Linder, Markus
AU - Rojas, Orlando
PY - 2017/7/1
Y1 - 2017/7/1
N2 - Aerogels prepared from aqueous dispersions of anionic and cationic cellulose nanofibrils (CNFs) were investigated as solid supports for enzymes and silver nanoparticles and to elicit a sustained antibacterial effect. The imparted stabilization in dry conditions was studied with aerogels that were cast after mixing the enzymes with CNFs followed by dehydration (freeze-drying). The activity of lysozyme immobilized in the given CNF system was analyzed upon storage in liquid and air media. In contrast with aqueous solutions of free, unbound enzyme, which lost activity after the first day, the enzyme immobilized physically in unmodified and cationic CNF presented better stability (activity for a longer time). However, the enzyme activity was reduced in the case of anionic CNF, which was prepared by TEMPO-mediated oxidation (TO-CNF). Both humidity and temperature reduced the stability of the enzyme immobilized in the respective CNF aerogel. The antibacterial activity of CNF aerogels carrying lysozyme was also tested against gram-negative and gram-positive bacteria. The results were compared with those obtained from CNF systems loaded with silver nanoparticles (AgNP) after in situ synthesis via UV reduction. Storage in cold or dry conditions preserved the activity and antibacterial performance of enzyme-loaded CNF aerogels. As expected, the lysozyme-containing aerogels showed lower inhibition than the AgNP-containing aerogel. In this latter case, the antibacterial activity depended on the concentration and size of the nanoparticles. Compared to unmodified CNF and TO-CNF, the aerogels prepared with cationic CNF, loaded with either lysozyme or AgNPs, showed remarkably better antibacterial activity. Similar experiments were conducted with horseradish peroxidase, which confirmed, to different degrees, the observations derived from the lysozyme systems. Overall, the results indicate that non-toxic and biodegradable CNF is a suitable support for bio-active materials and is effective in protecting and retaining enzymatic and antibacterial activities.
AB - Aerogels prepared from aqueous dispersions of anionic and cationic cellulose nanofibrils (CNFs) were investigated as solid supports for enzymes and silver nanoparticles and to elicit a sustained antibacterial effect. The imparted stabilization in dry conditions was studied with aerogels that were cast after mixing the enzymes with CNFs followed by dehydration (freeze-drying). The activity of lysozyme immobilized in the given CNF system was analyzed upon storage in liquid and air media. In contrast with aqueous solutions of free, unbound enzyme, which lost activity after the first day, the enzyme immobilized physically in unmodified and cationic CNF presented better stability (activity for a longer time). However, the enzyme activity was reduced in the case of anionic CNF, which was prepared by TEMPO-mediated oxidation (TO-CNF). Both humidity and temperature reduced the stability of the enzyme immobilized in the respective CNF aerogel. The antibacterial activity of CNF aerogels carrying lysozyme was also tested against gram-negative and gram-positive bacteria. The results were compared with those obtained from CNF systems loaded with silver nanoparticles (AgNP) after in situ synthesis via UV reduction. Storage in cold or dry conditions preserved the activity and antibacterial performance of enzyme-loaded CNF aerogels. As expected, the lysozyme-containing aerogels showed lower inhibition than the AgNP-containing aerogel. In this latter case, the antibacterial activity depended on the concentration and size of the nanoparticles. Compared to unmodified CNF and TO-CNF, the aerogels prepared with cationic CNF, loaded with either lysozyme or AgNPs, showed remarkably better antibacterial activity. Similar experiments were conducted with horseradish peroxidase, which confirmed, to different degrees, the observations derived from the lysozyme systems. Overall, the results indicate that non-toxic and biodegradable CNF is a suitable support for bio-active materials and is effective in protecting and retaining enzymatic and antibacterial activities.
KW - antibacterial aerogel
KW - cellulose nanofibrils (CNF)
KW - enzyme stability
KW - lysozyme
KW - silver nanoparticles
UR - http://www.scopus.com/inward/record.url?scp=85018791478&partnerID=8YFLogxK
U2 - 10.1007/s10570-017-1311-0
DO - 10.1007/s10570-017-1311-0
M3 - Article
VL - 24
SP - 2837
EP - 2848
JO - Cellulose
JF - Cellulose
SN - 0969-0239
IS - 7
ER -