Cytotoxic effect of silver nanoparticles synthesized from Padina tetrastromatica on breast cancer cell line View the table of contents for this issue, or go to the journal homepage for more 2016 Adv. Nat. Sci: Nanosci. Nanotechnol. 7 035015

The present study was aimed to synthesize silver nanoparticles (AgNPs) from the aqueous extracts of Odontosoria chinensis (L.) J. Sm. and the synthesized AgNPs were examined for their biopotentials. The Odontosoria chinensis extracts were added to 1 mM AgNO₃ solution with different ratios viz., 0.5:9.5, 1:9, 1.5:8.5 and 2:8 ratios for the reduction of Ag ions. After reduction, the AgNPs of Odontosoria chinensis were analyzed spectroscopically for further confirmation. The synthesized AgNPs of Odontosoria chinensis were characterized by pH, ultra violet–visible spectroscopy (UV-Vis), Fourier transform–infra red spectroscopy (FT-IR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDAX) and X-Ray diffraction (XRD). The time taken for the complete reduction of Silver (Ag) in solution to nanoparticle was 10 min. The O. chinensis aqueous extracts mediated silver nanoparticles showed a broad peak with distinct absorption at around 400–420 nm and confirmed the silver nanoparticle formation. FT-IR results also confirmed the existence of organic materials in the silver nanoparticles of O. chinensis. The EDX spectra of AgNPs of O. chinenesis revealed the occurrence of a strong Ag peak. The synthesis of AgNPs of O. chinenesis was confirmed with the existence of a peak at 46.228°. The toxic potential of AgNPs of O. chinenesis showed varied percentage mortality with the LC₅₀ values of 134.68 μL/ 50 mL and 76.5 μL/50 mL, respectively. The anti-inflammatory and anti-diabetic activities of aqueous and AgNPs of O. chinenesis were statistically significant at p < 0.05 level. Conclusion: The results demonstrated the toxicity, anti-diabetic and anti-inflammatory potential of the studied AgNPs. The synthesized nanoparticles of Odontosoria chinensis could be tested as an alternative to anticancer, anti-diabetic and anti-inflammatory drugs.

Silver nanoparticles (AgNPs) are an important class of nanomaterials, which have used as antimicrobial and disinfectant agents due to their detrimental effect on target cells. In the present study it was explored to deliver a novel tamoxifen drug system that can be used in breast cancer treatment, based on chitosan coated silver nanoparticles on MCF-7 human breast cancer cells. AgNPs synthesized from Adenia hondala tuber extract were used to make the chitosan coated AgNPs (Ch-AgNPs), in which the drug tamoxifen was loaded on chitosan coated silver nanoparticles (Tam-Ch-AgNPs) to construct drug loaded nanoparticles as drug delivery system. The morphology and characteristics of the Ch-AgNPs were investigated by UV, FTIR, zeta potential and FESEM. Furthermore, the toxicity of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs was evaluated through cell viability, lactate dehydrogenase leakage, reactive oxygen species generation, caspase-3, DNA laddering, and TUNEL assay in human breast cancer cells (MCF-7) and HBL-100 continuous cell line as a control. Treatment of cancer cells with various concentrations of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs for 24 h revealed that Tam-Ch-AgNPs could inhibit cell viability and induce significant membrane leakage in a dose-dependent manner. Cells exposed to Tam-Ch-AgNPs showed increased reactive oxygen species and hydroxyl radical production when compared to AgNPs, Ch-AgNPs. Furthermore, the apoptotic effects of AgNPs, Ch-AgNPs, Tam-Ch-AgNPs were confirmed by activation of caspase-3 and DNA nuclear fragmentation. The present findings suggest that Tam-Ch-AgNPs could contribute to the development of a suitable anticancer drug delivery.

Carbon quantum dots (CQDs) have shown great potential for drug delivery systems due to their small size and properties. Surface functionalization of CQDs directly affects the drug conjugation and release behaviour. In this study, the peanut shell carbon quantum dots (PS-CQDs) were synthesised through the hydrothermal method. The as-synthesised PS-CQDs had blue fluorescence and functional groups of hydroxyl, carboxyl, and amine. These surface group shows that the PS-CQDs have great water solubility. The free radical scavenging efficacy was also analysed and found to be 84.7%. With an average size of 2.1 ± 0.02 nm, the PS-CQDs were functionalized with a hydrazine group and then conjugated with doxorubicin. The doxorubicin conjugated sample DOX-PS-CQDs showed pH-sensitive release of the drug. The cumulative release percentage was 55.4% at pH 7.4 and 81.4% at pH 6.5, and the release profile exhibited sustained release within 24 h. The different pH enables the PS-CQDs based nanocarrier to release the drug at tumour sites efficiently. Further, in-vitro anticancer activity was studied using these PS-CQDs based nanocarriers against the MDA MB231 cell line, and the live/dead cell screening was carried out by AO/EB staining. Thus, the doxorubicin conjugated with PS-CQDs has exhibited promising properties as a drug carrier for cancer therapy.