title: Bio-conjugation of antioxidant peptide on surface-modified gold nanoparticles: a novel approach to enhance the radical scavenging property in cancer cell.
abstract: BACKGROUND
  Functionalized gold nanoparticles are emerging as a promising nanocarrier for target specific delivery of the therapeutic molecules in a cancer cell, as a result it targeted selectively to the cancer cell and minimized the off-target effect. The functionalized nanomaterial (bio conjugate) brings novel functional properties, for example, the high payload of anticancer, antioxidant molecules and selective targeting of the cancer molecular markers. The current study reported the synthesis of multifunctional bioconjugate (GNPs-Pep-A) to target the cancer cell.
  
  
  METHODS
  The GNPs-Pep-A conjugate was prepared by functionalization of GNPs with peptide-A (Pro-His-Cys-Lys-Arg-Met; Pep-A) using thioctic acid as a linker molecule. The GNPs-Pep-A was characterized and functional efficacy was tested using Retinoblastoma (RB) cancer model in vitro.
  
  
  RESULTS
  The GNPs-Pep-A target the reactive oxygen species (ROS) in RB, Y79, cancer cell more effectively, and bring down the ROS up to 70 % relative to control (untreated cells) in vitro. On the other hand, Pep-A and GNPs showed 40 and 9 % reductions in ROS, respectively, compared to control. The effectiveness of bioconjugate indicates the synergistic effect, due to the coexistence of both organic (Pep-A) and inorganic phase (GNPs) in novel GNPs-Pep-A functional material. In addition to this, it modulates the mRNA expression of antioxidant genes glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) by two-threefolds as observed.
  
  
  CONCLUSIONS
  The effects of GNPs-Pep-A on ROS reduction and regulation of antioxidant genes confirmed thatVitis vinifera L. polyphenol-coated GNPs synergistically improve the radical scavenging properties and enhanced the apoptosis of cancer cell.
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.|Centre for Chemistry and Biotechnology, Deakin University, Geelong campus, Geelong, VIC 3216 Australia.
authors.forename: Sushma
authors.initials: S
authors.lastname: Kalmodia
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: Suryanarayanan
authors.initials: S
authors.lastname: Vandhana
authors.affiliation: Centre for Chemistry and Biotechnology, Deakin University, Geelong campus, Geelong, VIC 3216 Australia.
authors.forename: B R
authors.initials: BR
authors.lastname: Tejaswini Rama
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: Balasubramanyam
authors.initials: B
authors.lastname: Jayashree
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: T
authors.initials: T
authors.lastname: Sreenivasan Seethalakshmi
authors.affiliation: Center for Bioinformatics, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: Vetrivel
authors.initials: V
authors.lastname: Umashankar
authors.affiliation: Centre for Chemistry and Biotechnology, Deakin University, Geelong campus, Geelong, VIC 3216 Australia.
authors.forename: Wenrong
authors.initials: W
authors.lastname: Yang
authors.affiliation: Centre for Chemistry and Biotechnology, Deakin University, Geelong campus, Geelong, VIC 3216 Australia.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Barrow
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Krishnakumar
authors.affiliation: Department of Nano-biotechnology, Vision Research Foundation, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai, 600 006 India.
authors.forename: Sailaja V
authors.initials: SV
authors.lastname: Elchuri
keywords: Antioxidant peptide; Cancer cell; Conjugate; Gold nanoparticles (GNPs); Oxidative stress; Reactive oxygen species (ROS)