Encapsulation of Single Enzyme in Nanogel with Enhanced Biocatalytic Activity and Stability

Yan, Ming; Ge, Jun; Liu, Zheng; Ouyang, Pingkai

doi:10.1021/ja064126t

Cited by 289 publications

(261 citation statements)

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“…In this study, we seek to improve the stability of self-illuminating QDs through a polymeric encapsulation method. We adopted the procedure reported by Yan et al [15] for its simplicity (only 2 steps) and compatibility in aqueous media, since treatment with organic solvents such as that reported by Kim & Grate [14] may result in the disruption of the QD-protein assembly and inactivation of the BRET donor--Luc8 protein.…”

Section: Discussionmentioning

confidence: 99%

“…This scheme consists of multiple steps including surface modification, lyophilization, polymerization in organic solvent and shell condensation. More recently, Yan et al reported a new two-step procedure that involves surface acryloylation and in situ aqueous polymerization to encapsulate a single enzyme in a nanogel [15]. The authors applied this technique to both horseradish peroxidase and bovine carbonic anhydrase [15,16], and both showed excellent preservation of their biocatalytic activities (70-80%).…”

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confidence: 99%

“…More recently, Yan et al reported a new two-step procedure that involves surface acryloylation and in situ aqueous polymerization to encapsulate a single enzyme in a nanogel [15]. The authors applied this technique to both horseradish peroxidase and bovine carbonic anhydrase [15,16], and both showed excellent preservation of their biocatalytic activities (70-80%). Encouraged by these results, in this study, we applied this approach to improve the serum stability of QD-BRET conjugates.…”

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confidence: 99%

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Improved QD-BRET conjugates for detection and imaging

Xing

Koh

et al. 2008

Biochemical and Biophysical Research Communications

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Self-illuminating quantum dots, also known as QD-BRET conjugates, are a new class of quantum dots bioconjugates which do not need external light for excitation. Instead, light emission relies on the bioluminescence resonance energy transfer from the attached Renilla luciferase enzyme, which emits light upon the oxidation of its substrate. QD-BRET combines the advantages of the QDs (such as superior brightness & photostability, tunable emission, multiplexing) as well as the high sensitivity of bioluminescence imaging, thus holds the promise for improved deep tissue in vivo imaging. Although studies have demonstrated the superior sensitivity and deep tissue imaging potential, the stability of the QD-BRET conjugates in biological environment needs to be improved for long-term imaging studies such as in vivo cell trafficking. In this study, we seek to improve the stability of QD-BRET probes through polymeric encapsulation with a polyacrylamide gel. Results show that encapsulation caused some activity loss, but significantly improved both the in vitro serum stability and in vivo stability when subcutaneously injected into the animal. Stable QD-BRET probes should further facilitate their applications for both in vitro testing as well as in vivo cell tracking studies. Keywordsself-illuminating quantum dots; bioluminescence resonance energy transfer (BRET); polymeric encapsulation; molecular imaging; nanotechnology Semiconductor quantum dots (QDs) have captivated scientists and engineers over the past two decades owing to their fascinating optical and electronic properties, which are not available from either single individual molecules or bulk solids [1]. Compared with organic dyes and fluorescent proteins, semiconductor QDs offer several unique advantages, such as size-and composition-tunable emission from visible to infrared wavelengths, large absorption coefficients across a wide spectral range, and very high levels of brightness and photostability [2]. These properties make them appealing fluorescent probes for bioimaging applications including in situ cell/tissue labeling, live cell imaging and in vivo imaging [3]. However, in vivo imaging using quantum dots still faces challenges such as interferences from tissue autofluorescence [4] and paucity of light available at non-superficial tissue sites [5]. One approach to solve these problems is to use high quality near infrared (NIR) QDs [6], which is an area still under active development. Alternatively, since both problems are related to the

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Section: Discussionmentioning

confidence: 99%

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Improved QD-BRET conjugates for detection and imaging

Xing

Koh

et al. 2008

Biochemical and Biophysical Research Communications

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“…As an innovative way of enzyme stabilization, "singleenzyme nanoparticles (SENs)" technology was rather attractive because enzyme in the nanoparticle exhibited very good stability under harsh conditions (Hegedus and Nagy, 2009;Yan et al, 2006). Kim and Grate (2003) have developed armored SENs that surround each enzyme molecule with a porous composite organic/ inorganic network of less than a few nanometers thick.…”

Section: New Technologies For Enzyme Immobilization 321 Single Enzymentioning

confidence: 99%

The Art of Immobilization Using Biopolymers, Biomaterials and Nanobiotechnology

Elnashar¹

2011

Biotechnology of Biopolymers

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“…4 Nanogels have shown a rapid progress from being unwanted by-products of polymerization processes to an imperative subject of interdisciplinary research in different areas of polymer chemistry and physics, material, pharmaceutical and medical sciences. Some examples of biomedical applications of nanogels are their usages as potential gene and antisense delivery agents, 5 toxin scavengers, 6 carriers for encapsulation of enzymes to increase biocatalytic activity and stability, 7 usage in cancer chemotherapy 8 and controlling cholesterol. 9 In these cases of biomedical application, the toxicity issues of materials are considered with more emphasis.…”

Section: Introductionmentioning

confidence: 99%