title: Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating.
abstract: BACKGROUND
  Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost- effective and high loading capacity method is still challenging.
  
  
  RESULTS
  A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs). Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation.
  
  
  CONCLUSIONS
  Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China. yhren@ecust.edu.cn
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Ren
authors.forename: Jose G
authors.initials: JG
authors.lastname: Rivera
authors.forename: Lihong
authors.initials: L
authors.lastname: He
authors.forename: Harsha
authors.initials: H
authors.lastname: Kulkarni
authors.forename: Dong-Keun
authors.initials: DK
authors.lastname: Lee
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Messersmith
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D004298:Dopamine / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry; D013696:Temperature
chemical_list: D004800:Enzymes, Immobilized; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D011108:Polymers; C000499:ferric oxide; D008049:Lipase; D004298:Dopamine