Polydopamine microcapsules with different wall structures prepared by a template-mediated method for enzyme immobilization.
Microcapsules with diverse wall structures may exhibit different performance in specific applications. In the present study, three kinds of mussel-inspired polydopamine (PDA) microcapsules with different wall structures have been prepared by a template-mediated method. More specifically, three types of CaCO3 microspheres (poly(allylamine hydrochloride), (PAH)-doped CaCO3; pure-CaCO3; and poly(styrene sulfonate sodium), (PSS)-doped CaCO3) were synthesized as sacrificial templates, which were then treated by dopamine to obtain the corresponding PDA-CaCO3 microspheres. Through treating these microspheres with disodium ethylene diamine tetraacetic acid (EDTA-2Na) to remove CaCO3, three types of PDA microcapsules were acquired: that was (1) PAH-PDA microcapsule with a thick (∼600 nm) and highly porous capsule wall composed of interconnected networks, (2) pure-PDA microcapsule with a thick (∼600 nm) and less porous capsule wall, (3) PSS-PDA microcapsule with a thin (∼70 nm) and dense capsule wall. Several characterizations confirmed that a higher degree in porosity and interconnectivity of the capsule wall would lead to a higher mass transfer coefficient. When serving as the carrier for catalase (CAT) immobilization, these enzyme-encapsulated PDA microcapsules showed distinct structure-related activity and stability. In particular, PAH-PDA microcapsules with a wall of highly interconnected networks displayed several significant advantages, including increases in enzyme encapsulation efficiency and enzyme activity/stability and a decrease in enzyme leaching in comparison with other two types of PDA microcapsules. Besides, this hierarchically structured PAH-PDA microcapsule may find other promising applications in biocatalysis, biosensors, drug delivery, etc.
Key Laboratory for Green Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China.
Jiafu
J
Shi
Chen
C
Yang
Shaohua
S
Zhang
Xiaoli
X
Wang
Zhongyi
Z
Jiang
Wenyan
W
Zhang
Xiaokai
X
Song
Qinghong
Q
Ai
Chunyong
C
Tian
D055162:Biocatalysis; D015374:Biosensing Techniques; D002119:Calcium Carbonate / Q000737:chemistry; D002214:Capsules / Q000737:chemistry*; D002374:Catalase / Q000737:chemistry* / Q000378:metabolism; D004492:Edetic Acid / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D007211:Indoles / Q000737:chemistry*; D007700:Kinetics; D011108:Polymers / Q000737:chemistry*
D002214:Capsules; D004800:Enzymes, Immobilized; D007211:Indoles; D011108:Polymers; C568283:polydopamine; D004492:Edetic Acid; D002374:Catalase; D002119:Calcium Carbonate