title: Functional characterization of recombinant human granulocyte colony stimulating factor (hGMCSF) immobilized onto silica nanoparticles.
abstract: OBJECTIVE
  Granulocyte macrophage colony stimulating factor (GMCSF), an important therapeutic cytokine, was immobilized onto silica nanoparticles. Maintenance of structural integrity and biological performance in immobilized cytokine was assessed to augment its applicability in possible biomedical implications.
  
  
  RESULTS
  Following its cloning and expression in E. coli, the recombinant human GMCSF (hGMCSF) was purified as a GST-tagged protein corresponding to a 42 kDa band on SDS-PAGE. The purified cytokine was immobilized onto biocompatible silica nanoparticles (~129.4 nm) by adsorption and the binding was confirmed by dynamic light scattering and infrared spectroscopy. Maximum binding of hGMCSF was at 6.4 µg mg(-1) silica nanoparticles. Efficient release of the cytokine from the nanoparticles with its structural integrity intact was deduced from circular dichroism spectroscopy. hGMCSF-immobilized silica nanoparticles efficiently increased the proliferation of RAW 264.7 macrophage cells with 50 % increase in proliferation at 600 ng hGMCSF µg(-1) silica nanoparticles.
  
  
  CONCLUSIONS
  Silica nanoparticles successfully immobilized hGMCSF maintaining its structural integrity. The release of the immobilized cytokine from silica nanoparticles resulted in the increased proliferation of macrophages indicating the potential of the system in future applications.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Selvarajan
authors.initials: S
authors.lastname: Vanitha
authors.affiliation: Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Upashi
authors.initials: U
authors.lastname: Goswami
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Chaubey
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India. sghosh@iitg.ernet.in.|Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India. sghosh@iitg.ernet.in.
authors.forename: Siddhartha S
authors.initials: SS
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India. psanpui@iitg.ernet.in.
authors.forename: Pallab
authors.initials: P
authors.lastname: Sanpui
mesh_terms: D000327:Adsorption; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004337:Drug Carriers; D000067493:Dynamic Light Scattering; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008970:Molecular Weight; D053758:Nanoparticles; D000067996:RAW 264.7 Cells; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012822:Silicon Dioxide; D013055:Spectrophotometry, Infrared
chemical_list: D004337:Drug Carriers; D055767:Immobilized Proteins; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D012822:Silicon Dioxide
keywords: Immobilization; Macrophage proliferation; Recombinant hGMCSF; Silica nanoparticles; Therapeutic cytokine