76
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Cai J, Hsiao BS, Gross RA. Real-Time Structure Changes during Uniaxial Stretching of Poly(ω-pentadecalactone) by in Situ Synchrotron WAXD/SAXS Techniques. Macromolecules 2011. [DOI: 10.1021/ma102949h] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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77
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Kundu S, Bhangale AS, Wallace WE, Flynn KM, Guttman CM, Gross RA, Beers KL. Continuous flow enzyme-catalyzed polymerization in a microreactor. J Am Chem Soc 2011; 133:6006-11. [PMID: 21438577 DOI: 10.1021/ja111346c] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enzymes immobilized on solid supports are increasingly used for greener, more sustainable chemical transformation processes. Here, we used microreactors to study enzyme-catalyzed ring-opening polymerization of ε-caprolactone to polycaprolactone. A novel microreactor design enabled us to perform these heterogeneous reactions in continuous mode, in organic media, and at elevated temperatures. Using microreactors, we achieved faster polymerization and higher molecular mass compared to using batch reactors. While this study focused on polymerization reactions, it is evident that similar microreactor based platforms can readily be extended to other enzyme-based systems, for example, high-throughput screening of new enzymes and to precision measurements of new processes where continuous flow mode is preferred. This is the first reported demonstration of a solid supported enzyme-catalyzed polymerization reaction in continuous mode.
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78
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Yang Y, Lu W, Cai J, Hou Y, Ouyang S, Xie W, Gross RA. Poly(oleic diacid-co-glycerol): Comparison of Polymer Structure Resulting from Chemical and Lipase Catalysis. Macromolecules 2011. [DOI: 10.1021/ma102939k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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79
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Liu C, Jiang Z, Decatur J, Xie W, Gross RA. Chain Growth and Branch Structure Formation during Lipase-Catalyzed Synthesis of Aliphatic Polycarbonate Polyols. Macromolecules 2011. [DOI: 10.1021/ma102899c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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80
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Juais D, Naves AF, Li C, Gross RA, Catalani LH. Isosorbide Polyesters from Enzymatic Catalysis. Macromolecules 2010. [DOI: 10.1021/ma1013176] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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81
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Lu W, Ness JE, Xie W, Zhang X, Minshull J, Gross RA. Biosynthesis of Monomers for Plastics from Renewable Oils. J Am Chem Soc 2010; 132:15451-5. [DOI: 10.1021/ja107707v] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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82
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Viswanathan K, Omorebokhae R, Li G, Gross RA. Protease-Catalyzed Oligomerization of Hydrophobic Amino Acid Ethyl Esters in Homogeneous Reaction Media Using l-Phenylalanine as a Model System. Biomacromolecules 2010; 11:2152-60. [DOI: 10.1021/bm100516x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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83
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Gross RA, Ganesh M, Lu W. Enzyme-catalysis breathes new life into polyester condensation polymerizations. Trends Biotechnol 2010; 28:435-43. [PMID: 20598389 DOI: 10.1016/j.tibtech.2010.05.004] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 05/26/2010] [Accepted: 05/27/2010] [Indexed: 12/16/2022]
Abstract
Traditional chemical catalysts for polyester synthesis have enabled the generation of important commercial products. Undesirable characteristics of chemically catalyzed condensation polymerizations include the need to conduct reactions at high temperatures (150-280 degrees C) with metal catalysts that are toxic and lack selectivity. The latter is limiting when aspiring towards synthesis of increasingly complex and well-defined polyesters. This review describes an exciting technology that makes use of immobilized enzyme-catalysts for condensation polyester synthesis. Unlike chemical catalysts, enzymes function under mild conditions (< or =100 degrees C), which enables structure retention when polymerizing unstable monomers, circumvents the introduction of metals, and also provides selectivity that avoids protection-deprotection steps and presents unique options for structural control. Examples are provided that describe the progress made in enzyme-catalyzed polymerizations, as well as current limitations and future prospects for developing more efficient enzyme-catalysts for industrial processes.
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84
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Focarete ML, Gualandi C, Scandola M, Govoni M, Giordano E, Foroni L, Valente S, Pasquinelli G, Gao W, Gross RA. Electrospun scaffolds of a polyhydroxyalkanoate consisting of omega-hydroxylpentadecanoate repeat units: fabrication and in vitro biocompatibility studies. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2010; 21:1283-96. [PMID: 20534185 DOI: 10.1163/092050609x12517190417597] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Electrospinning was used to fabricate fibrous scaffolds of lipase-catalyzed poly(omega-pentadecalactone) (PPDL). The slow resorbability of this biomaterial is expected to be valuable for tissue-engineering applications requiring long healing times. The effect of solvent systems and instrumental parameters on fiber morphology was investigated. PPDL electrospinning was optimized and defect-free fibers (diameter 410 +/- 150 nm) were obtained by using a mixed three-solvent system. Scaffolds were characterized by scanning electron microscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXS). TGA showed no residual solvent in the scaffolds. DSC and WAXS results indicated that electrospun PPDL is semicrystalline. Biocompatibility of PPDL scaffolds was evaluated through indirect cytotoxicity tests using embryonic rat cardiac H9c2 cells. The ability of PPDL electrospun mats to support cell growth was verified by culturing H9c2 cells onto the scaffold. Cell adhesion, proliferation and morphology were evaluated. The results indicated that PPDL mats are not cytotoxic and they support proliferation of H9c2 cells. The cumulative results of this study suggest further exploration of PPDL fibrous mats as scaffolds for tissue-engineered constructs.
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85
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Viswanathan K, Li G, Gross RA. Protease Catalyzed In Situ C-Terminal Modification of Oligoglutamate. Macromolecules 2010. [DOI: 10.1021/ma100562j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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86
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Cai J, Liu C, Cai M, Zhu J, Zuo F, Hsiao BS, Gross RA. Effects of molecular weight on poly(ω-pentadecalactone) mechanical and thermal properties. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.01.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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87
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Feder D, Gross RA. Exploring Chain Length Selectivity in HIC-Catalyzed Polycondensation Reactions. Biomacromolecules 2010; 11:690-7. [DOI: 10.1021/bm901272r] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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88
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Gualandi C, White LJ, Chen L, Gross RA, Shakesheff KM, Howdle SM, Scandola M. Scaffold for tissue engineering fabricated by non-isothermal supercritical carbon dioxide foaming of a highly crystalline polyester. Acta Biomater 2010; 6:130-6. [PMID: 19619678 DOI: 10.1016/j.actbio.2009.07.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/20/2009] [Accepted: 07/15/2009] [Indexed: 11/28/2022]
Abstract
Porous scaffolds of a random co-polymer of omega-pentadecalactone (PDL) and epsilon-caprolactone (CL) (poly(PDL-CL)), synthesized by biocatalysis, were fabricated by supercritical carbon dioxide (scCO(2)) foaming. The co-polymer, containing 31 mol.% CL units, is highly crystalline (T(m) = 82 degrees C, DeltaH(m) = 105 J g(-1)) thanks to the ability of the two monomer units to co-crystallize. The co-polymer can be successfully foamed upon homogeneous absorption of scCO(2) at T > T(m). The effect of soaking time, depressurization rate and cooling rate on scaffold porosity, pore size distribution and pore interconnectivity was investigated by micro X-ray computed tomography. Scaffolds with a porosity in the range 42-76% and an average pore size of 100-375 microm were successfully obtained by adjusting the main foaming parameters. Process conditions in the range investigated did not affect the degree of crystallinity of poly(PDL-CL) scaffolds. A preliminary study of the mechanical properties of the scaffolds revealed that poly(PDL-CL) foams may find application in the regeneration of cartilage tissue.
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89
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Yang Y, Lu W, Zhang X, Xie W, Cai M, Gross RA. Two-Step Biocatalytic Route to Biobased Functional Polyesters from ω-Carboxy Fatty Acids and Diols. Biomacromolecules 2009; 11:259-68. [DOI: 10.1021/bm901112m] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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90
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Ganesh M, Dave RN, L’Amoreaux W, Gross RA. Embedded Enzymatic Biomaterial Degradation. Macromolecules 2009. [DOI: 10.1021/ma901481h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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91
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Gao W, Liu XM, Gross RA. Determination of molar mass and solution properties of cationic hydroxyethyl cellulose derivatives by multi-angle laser light scattering with simultaneous refractive index detection. POLYM INT 2009. [DOI: 10.1002/pi.2636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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92
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Ronkvist ÅM, Lu W, Feder D, Gross RA. Cutinase-Catalyzed Deacetylation of Poly(vinyl acetate). Macromolecules 2009. [DOI: 10.1021/ma900530j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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93
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Ronkvist ÅM, Xie W, Lu W, Gross RA. Cutinase-Catalyzed Hydrolysis of Poly(ethylene terephthalate). Macromolecules 2009. [DOI: 10.1021/ma9005318] [Citation(s) in RCA: 341] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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94
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Cai J, Hsiao BS, Gross RA. Polypentadecalactone prepared by lipase catalysis: crystallization kinetics and morphology. POLYM INT 2009. [DOI: 10.1002/pi.2624] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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95
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Chen B, Pernodet N, Rafailovich MH, Bakhtina A, Gross RA. Protein immobilization on epoxy-activated thin polymer films: effect of surface wettability and enzyme loading. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13457-64. [PMID: 18991420 DOI: 10.1021/la8019952] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A series of epoxy-activated polymer films composed of poly(glycidyl methacrylate/butyl methacrylate/hydroxyethyl methacrylate) were prepared. Variation in comonomer composition allowed exploration of relationships between surface wettability and Candida antartica lipase B (CALB) binding to surfaces. By changing solvents and polymer concentrations, suitable conditions were developed for preparation by spin-coating of uniform thin films. Film roughness determined by AFM after incubation in PBS buffer for 2 days was less than 1 nm. The occurrence of single CALB molecules and CALB aggregates at surfaces was determined by AFM imaging and measurements of volume. Absolute numbers of protein monomers and multimers at surfaces were used to determine values of CALB specific activity. Increased film wettability, as the water contact angle of films increased from 420 to 550, resulted in a decreased total number of immobilized CALB molecules. With further increases in the water contact angle of films from 55 degrees to 63 degrees, there was an increased tendency of CALB molecules to form aggregates on surfaces. On all flat surfaces, two height populations, differing by more than 30%, were observed from height distribution curves. They are attributed to changes in protein conformation and/or orientation caused by protein-surface and protein-protein interactions. The fraction of molecules in these populations changed as a function of film water contact angle. The enzyme activity of immobilized films was determined by measuring CALB-catalyzed hydrolysis of p-nitrophenyl butyrate. Total enzyme specific activity decreased by decreasing film hydrophobicity.
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96
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Poojari Y, Palsule AS, Cai M, Clarson SJ, Gross RA. Synthesis of organosiloxane copolymers using enzymatic polyesterification. Eur Polym J 2008. [DOI: 10.1016/j.eurpolymj.2008.07.043] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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97
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Zini E, Gazzano M, Scandola M, Wallner SR, Gross RA. Glycolipid Biomaterials: Solid-State Properties of a Poly(sophorolipid). Macromolecules 2008. [DOI: 10.1021/ma800496f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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98
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Li G, Raman VK, Xie W, Gross RA. Protease-Catalyzed Co-Oligomerizations of l-Leucine Ethyl Ester with l-Glutamic Acid Diethyl Ester: Sequence and Chain Length Distributions. Macromolecules 2008. [DOI: 10.1021/ma800946d] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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99
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Li G, Vaidya A, Xie W, Gao W, Gross RA. Enzyme-Catalyzed Oligopeptide Synthesis: Rapid Regioselective Oligomerization of L-Glutamic Acid Diethyl Ester Catalyzed by Papain. ACTA ACUST UNITED AC 2008. [DOI: 10.1021/bk-2008-0999.ch020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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100
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Jiang Z, Liu C, Gross RA. Lipase-Catalyzed Synthesis of Aliphatic Poly(carbonate-co-esters). Macromolecules 2008. [DOI: 10.1021/ma702868a] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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