Protein sorption and recovery by hydrogels using principles of aqueous two-phase extraction

Gehrke, Stevin H.; Vaid, Nitin R.; McBride, James F.

doi:10.1002/(sici)1097-0290(19980520)58:4<416::aid-bit9>3.0.co;2-m

Cited by 27 publications

(8 citation statements)

References 34 publications

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“…However, in this study, pure PEG-DA samples were prepared directly from the specified PEG-DA concentrations, which is why there was higher PEG-DA content (Fig. 5b) in the pure PEG-DA gels than in the IPNs (due to thermodynamic exclusion [36, 37]) in this study and not in our previous studies. This is an important distinction because PEG-DA content was an important contributing factor to the compressive (E) and especially shear (G) moduli in the current study.…”

Section: Discussionmentioning

confidence: 69%

Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering

Rennerfeldt¹,

Renth²,

Talata³

et al. 2013

Biomaterials

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Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells.

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Section: Discussionmentioning

confidence: 69%

Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering

Rennerfeldt¹,

Renth²,

Talata³

et al. 2013

Biomaterials

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“…The most used protein loading strategy is to utilize the equilibrium swelling of a hydrogel in a protein-containing solution. According to the studies of Gehrke et al , high protein-loading efficiency can also be achieved via partitioning proteins from polymer solutions of low affinity [84]. Thermal-responsive materials are typically materials with properties, such as solubility, displaying a nonlinear relationship with temperature.…”

Section: External Stimuli-triggered Deliverymentioning

confidence: 99%

Stimuli-responsive nanomaterials for therapeutic protein delivery

Lü

Sun

2014

Journal of Controlled Release

382

285

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Protein therapeutics have emerged as a significant role in treatment of a broad spectrum of diseases, including cancer, metabolic disorders and autoimmune diseases. The efficacy of protein therapeutics, however, is limited by their instability, immunogenicity and short half-life. In order to overcome these barriers, tremendous efforts have recently been made in developing controlled protein delivery systems. Stimuli-triggered release is an appealing and promising approach for protein delivery and has made protein delivery with both spatiotemporal- and dosage-controlled manners possible. This review surveys recent advances in controlled protein delivery of proteins or peptides using stimuli-responsive nanomaterials. Strategies utilizing both physiological and external stimuli are introduced and discussed.

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“…Therefore, development of separation processes using aqueous two-phase systems relied upon extensive empirical experimentation, which could be significantly simplified by using factorial experimental design methods [23]. In this study, a three-factorial central composite design was employed for the purification of Acinetobacter sp.…”

Section: Discussionmentioning

confidence: 99%

Two Step Purification of Acinetobacter sp. Lipase and Its Evaluation as a Detergent Additive at Low Temperatures

Saisubramanian

Sivasubramanian

Nandakumar

et al. 2008

Appl Biochem Biotechnol

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Acinetobacter sp. lipase was purified to homogeneity by a two-step process. The crude enzyme (along with biomass) was subjected to partial purification by aqueous two phase system (ATPS), avoiding centrifugation and filtration steps. Conditions for lipase partitioning by ATPS were optimized by response surface methodology (RSM) and a combination of 29.45% polyethylene glycol 8000, 15.5% phosphate, and a pH of 7.0 resulted in an optimal partition coefficient. Partially pure lipase was further purified by a modified batch process using Octyl Sepharose CL-4B in a vacuum filtration apparatus. This two-step process resulted in a purified lipase with a yield of 74.6% having a specific activity of 88.8 U/mg of protein and a purification fold of 14.92. The homogeneity of the lipase preparation obtained by the purification process was confirmed by reversed phase high performance liquid chromatography profile. The molecular weight of the purified lipase was found to be around 32 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified lipase exhibited pH and temperature optima of 8.5 and 37 degrees C, respectively. The lipase was active at low temperatures and it retained 86.8% activity at 10 degrees C. It also displayed other features such as stability over a broad range of pH (3.0-9.0) as well as stability in the presence of hydrogen peroxide and commercial detergents. Based on these characteristics, the potential of this lipase as an additive in laundry detergent formulation was evaluated under low temperature wash conditions. The results indicated that Acinetobacter sp. lipase increased the washing efficiency of the detergent Nirma by 21-24% at 15 degrees C-20 degrees C, respectively.

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Protein sorption and recovery by hydrogels using principles of aqueous two-phase extraction

Cited by 27 publications

References 34 publications

Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering

Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering

Stimuli-responsive nanomaterials for therapeutic protein delivery

Two Step Purification of Acinetobacter sp. Lipase and Its Evaluation as a Detergent Additive at Low Temperatures

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