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Facile synthesis of biocompatible gold nanoparticles from Vites vinefera and its cellular internalization against HBL-100 cells.

Amarnath K, Mathew NL, Nellore J, Siddarth CR, Kumar J - Cancer Nanotechnol (2011)

Bottom Line: Current discovery demonstrates the rapid formation of gold nanoparticles with the phytochemicals present in grapes, which serve a dual role as synergistic reducing agents to reduce gold salts into gold nanoparticles and also as stabilizers to provide a robust coating on the gold nanoparticles in a single step.In addition, the grape-generated gold nanoparticles (GAuNPs, GSH-GAuNPs, LA-GAuNPs) have demonstrated remarkable affinity towards human breast cancer cells (HBL-100) in the present study.Other than gold salts, no "manmade" chemicals are used in this truly biogenic, green nanotechnological process which thereby paves the way for outstanding opening for their application in molecular imaging and cancer therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biochemistry, Dental College & Hospitals, Sathyabama University, Chennai, 600119 Tamil Nadu India.

ABSTRACT

The remarkable health benefits of the chemical cocktails occluded within Vites vinefera (grapes) have been broadly used as dietary supplements and as natural pharmaceuticals in the treatment of various diseases including human cancer. Current discovery demonstrates the rapid formation of gold nanoparticles with the phytochemicals present in grapes, which serve a dual role as synergistic reducing agents to reduce gold salts into gold nanoparticles and also as stabilizers to provide a robust coating on the gold nanoparticles in a single step. Furthermore, the grape-generated gold nanoparticles (GAuNPs), have demonstrated remarkable in vitro stability on specific functionalization with peptides (GSH) and thiol-containing compounds (lipoic acid) followed by the induction of cell-specific response. In addition, the grape-generated gold nanoparticles (GAuNPs, GSH-GAuNPs, LA-GAuNPs) have demonstrated remarkable affinity towards human breast cancer cells (HBL-100) in the present study. These studies thus signified the cellular internalization of GAuNPs and its conjugates by transmission electron microscopy through endocytosis into cancer cells. Notably, at higher concentration of gold nanoparticles conjugate, there was an asymmetric accumulation of gold nanoparticles in the periphery of the cell nucleus of the HBL-100 cells which was confirmed by fluorescence microscopy. Other than gold salts, no "manmade" chemicals are used in this truly biogenic, green nanotechnological process which thereby paves the way for outstanding opening for their application in molecular imaging and cancer therapy.

No MeSH data available.


Related in: MedlinePlus

Dose-dependent cytotoxicity of GAuNPs, GSH-GAuNPs, and LA-GAuNPs in HBL-100-cells after 24 h of exposure to different concentrations GAuNPs, GSH-GAuNPs, and LA-GAuNPs (10, 50, 100, and 150 μg/mL, respectively) using MTT assay. Values are expressed as percent over control
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Fig4: Dose-dependent cytotoxicity of GAuNPs, GSH-GAuNPs, and LA-GAuNPs in HBL-100-cells after 24 h of exposure to different concentrations GAuNPs, GSH-GAuNPs, and LA-GAuNPs (10, 50, 100, and 150 μg/mL, respectively) using MTT assay. Values are expressed as percent over control

Mentions: The techniques for the characterization of nanoparticle size and morphology are SEM (Bilati et al. 2005) and TEM (Teixeira et al. 2005). Figures 4 and 5 indicate the size and morphology as observed under SEM and TEM on AuNPs synthesized using grapes as spherical in shape within the size range of 20–45 nm (Figs. 3a and 4a). Investigations on experiments using commercially available catechins have unambiguously confirmed that catechins are excellent reducing and stabilizing agents to reduce Au (III) to the corresponding gold nanoparticles (Satish et al. 2009). In addition, the effect of pH (Gardea et al. 2003b), time (Huang et al. 2007), temperature (Groning et al. 2004), and measurement of charges (Shankar et al. 2004a) may also play a major role in the determination of shape and size of nanoparticles. However, the presence of some phytochemicals (Brust et al. 1994) might render a minimum stability by failing to provide effective coating to shield the nanoparticles from agglomeration studies to GAuNPS. In order to capitalize on the reduction powers of such phytochemicals, we have utilized GSH, a tripeptide and lipoic acid, an antioxidant as naturally available stabilizing agent in our reactions. Thus, GSH-GAuNPs (Figs. 3b and 4b) and LA-GAuNPs (Figs. 3c and 4c) sizes as measured by SEM and TEM are in good agreement and are in the range of 40–80 nm suggesting that thiols and peptides are capped on grape phytochemically reduced gold nanoparticles. Such size distribution analysis of capped and non-capped GAuNPs confirms that particles are well dispersed. This extra stability rendered by GSH and lipoic acid-capped AUNP arises due to the chemical inertness by the complete coverage of the gold core by GSH ligands. Gold nanoparticles can be stabilized by anionic ligands such as carboxylic acid derivatives like citrate, tartrate, and lipoic acid (Peng et al. 2007). Earlier studies showed that glutathione used for capping gold quantum clusters (AU-n-SG-m) (−SG, glutathione thiolate) is one such group of compounds which has been well known for the stability of the AUNPs synthesized chemically (Habeeb and Pradeep 2007). Moreover, he confirmed in his results that the bigger clusters, n > 25, can be converted into AU25SG18 by adding excess GSH. In addition, the six free electrons present in the conduction band of nanoparticulate gold make them potential candidates to bind with thiols and amines. Therefore, by changing the size and shape of AuNps, the SPB and scattering may be tuned for application in cellular imaging, drug delivery, and therapy.Fig. 4


Facile synthesis of biocompatible gold nanoparticles from Vites vinefera and its cellular internalization against HBL-100 cells.

Amarnath K, Mathew NL, Nellore J, Siddarth CR, Kumar J - Cancer Nanotechnol (2011)

Dose-dependent cytotoxicity of GAuNPs, GSH-GAuNPs, and LA-GAuNPs in HBL-100-cells after 24 h of exposure to different concentrations GAuNPs, GSH-GAuNPs, and LA-GAuNPs (10, 50, 100, and 150 μg/mL, respectively) using MTT assay. Values are expressed as percent over control
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Related In: Results  -  Collection

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Fig4: Dose-dependent cytotoxicity of GAuNPs, GSH-GAuNPs, and LA-GAuNPs in HBL-100-cells after 24 h of exposure to different concentrations GAuNPs, GSH-GAuNPs, and LA-GAuNPs (10, 50, 100, and 150 μg/mL, respectively) using MTT assay. Values are expressed as percent over control
Mentions: The techniques for the characterization of nanoparticle size and morphology are SEM (Bilati et al. 2005) and TEM (Teixeira et al. 2005). Figures 4 and 5 indicate the size and morphology as observed under SEM and TEM on AuNPs synthesized using grapes as spherical in shape within the size range of 20–45 nm (Figs. 3a and 4a). Investigations on experiments using commercially available catechins have unambiguously confirmed that catechins are excellent reducing and stabilizing agents to reduce Au (III) to the corresponding gold nanoparticles (Satish et al. 2009). In addition, the effect of pH (Gardea et al. 2003b), time (Huang et al. 2007), temperature (Groning et al. 2004), and measurement of charges (Shankar et al. 2004a) may also play a major role in the determination of shape and size of nanoparticles. However, the presence of some phytochemicals (Brust et al. 1994) might render a minimum stability by failing to provide effective coating to shield the nanoparticles from agglomeration studies to GAuNPS. In order to capitalize on the reduction powers of such phytochemicals, we have utilized GSH, a tripeptide and lipoic acid, an antioxidant as naturally available stabilizing agent in our reactions. Thus, GSH-GAuNPs (Figs. 3b and 4b) and LA-GAuNPs (Figs. 3c and 4c) sizes as measured by SEM and TEM are in good agreement and are in the range of 40–80 nm suggesting that thiols and peptides are capped on grape phytochemically reduced gold nanoparticles. Such size distribution analysis of capped and non-capped GAuNPs confirms that particles are well dispersed. This extra stability rendered by GSH and lipoic acid-capped AUNP arises due to the chemical inertness by the complete coverage of the gold core by GSH ligands. Gold nanoparticles can be stabilized by anionic ligands such as carboxylic acid derivatives like citrate, tartrate, and lipoic acid (Peng et al. 2007). Earlier studies showed that glutathione used for capping gold quantum clusters (AU-n-SG-m) (−SG, glutathione thiolate) is one such group of compounds which has been well known for the stability of the AUNPs synthesized chemically (Habeeb and Pradeep 2007). Moreover, he confirmed in his results that the bigger clusters, n > 25, can be converted into AU25SG18 by adding excess GSH. In addition, the six free electrons present in the conduction band of nanoparticulate gold make them potential candidates to bind with thiols and amines. Therefore, by changing the size and shape of AuNps, the SPB and scattering may be tuned for application in cellular imaging, drug delivery, and therapy.Fig. 4

Bottom Line: Current discovery demonstrates the rapid formation of gold nanoparticles with the phytochemicals present in grapes, which serve a dual role as synergistic reducing agents to reduce gold salts into gold nanoparticles and also as stabilizers to provide a robust coating on the gold nanoparticles in a single step.In addition, the grape-generated gold nanoparticles (GAuNPs, GSH-GAuNPs, LA-GAuNPs) have demonstrated remarkable affinity towards human breast cancer cells (HBL-100) in the present study.Other than gold salts, no "manmade" chemicals are used in this truly biogenic, green nanotechnological process which thereby paves the way for outstanding opening for their application in molecular imaging and cancer therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biochemistry, Dental College & Hospitals, Sathyabama University, Chennai, 600119 Tamil Nadu India.

ABSTRACT

The remarkable health benefits of the chemical cocktails occluded within Vites vinefera (grapes) have been broadly used as dietary supplements and as natural pharmaceuticals in the treatment of various diseases including human cancer. Current discovery demonstrates the rapid formation of gold nanoparticles with the phytochemicals present in grapes, which serve a dual role as synergistic reducing agents to reduce gold salts into gold nanoparticles and also as stabilizers to provide a robust coating on the gold nanoparticles in a single step. Furthermore, the grape-generated gold nanoparticles (GAuNPs), have demonstrated remarkable in vitro stability on specific functionalization with peptides (GSH) and thiol-containing compounds (lipoic acid) followed by the induction of cell-specific response. In addition, the grape-generated gold nanoparticles (GAuNPs, GSH-GAuNPs, LA-GAuNPs) have demonstrated remarkable affinity towards human breast cancer cells (HBL-100) in the present study. These studies thus signified the cellular internalization of GAuNPs and its conjugates by transmission electron microscopy through endocytosis into cancer cells. Notably, at higher concentration of gold nanoparticles conjugate, there was an asymmetric accumulation of gold nanoparticles in the periphery of the cell nucleus of the HBL-100 cells which was confirmed by fluorescence microscopy. Other than gold salts, no "manmade" chemicals are used in this truly biogenic, green nanotechnological process which thereby paves the way for outstanding opening for their application in molecular imaging and cancer therapy.

No MeSH data available.


Related in: MedlinePlus