Composite of AuNPs@SiO $$_{2}$$ 2 NPs@[(NIPAM)- $${\varvec{b}}$$ b -(Ala)] and its activity on leukemia cells

Abstract

Synthesis and characterization of thermo-sensitive block copolymer of N-isopropyl acryl amide-b-Alanine [(NIPAM)-b-(Alanine)] thin film and its doping with (AuNPs)-(SiO 2 NPs), (gold and silica nanoparticles) were reported. Further, composite effect on K562 (leukemia) cells was examined based on in vitro cell-based studies. The synthesis of SiO 2 NPs was followed through facile Stober's sol-gel synthesis methods. The individual morphology of [(NIPAM)-b-(Alanine)] thin film, AuNPs and SiO 2 NPs including [(NIPAM)-b-(Alanine)]@(Au)-(SiO 2 NPs) composite was confirmed by using TEM instrumentation. [(NIPAM)-b-(Alanine)] thin film was embedded with gold and silica nanoparticles followed by the sonication. The average size of AuNPs is 16 nm and for SiO 2 NPs, it is ∼368 nm (in diameter). Synthesized composite [(NIPAM)-b-(Alanine)]@(Au)@(SiO 2 NPs) is biocompatible for mankind use. However, composite used to examine the inhibitory activity on K562 cells and it shows ∼78% inhibition, which is significant value for 24 h treatment under humidified atmospheric conditions.

Solvent assisted size effect on AuNPs and significant inhibition on K562 cells

“…The chemical compound HAuCl 4 (tetrachloroaurate/auric acid) of $2.5 g was taken in a 250 mL RB ask (round bottom ask). This has been added with $60 mL of organic solvent DMF (dimethyl formamide) and allowed to stir for 12 h at 50 C. This is again added with the 0.5 g of NaBH 4 (sodium borohydrate) strong reducing agent and allowed to stir for 2 h at 50 C. Furthermore, to that mixture methanol (MeOH) $25 mL has been added and allowed to stir for 2 h at 50 C. 1,11,17,25 Finally, the sodium metal from reducing agent NaBH 4 was degraded with the methanol solvent. The end product of reaction was yellowish in colour and this solution was used to separate the metal (Au) nanoparticles through the high speed centrifugation at 10 000 RPM for 10 minutes.…”

“…The end product of reaction was dark red in colour and this solution was used to separate the metal (Au) nanoparticles through the high speed centrifugation at 10 000 RPM for 10 minutes. 1,11,17,[26][27][28][29] The nal AuNPs were dispersed in IPA (isopropanol) solution and used to prepare the samples for TEM, HRTEM and SAED characterizations. The physical appearance of nal gold sample has been reported in the inset of the Fig.…”

“…1,8,9 However, organic solvent NMPL (Nmethyl-2-pyrrolidone) has the lower reduction rate on metal/gold nanoparticles and it leads to the larger sized particles. 10,11 From the DMF and NMPL organic solvents it is evidenced that there is a chance to synthesize the gold nanoparticles in the size range of 8 to 40 nm (in diameter). With these organic solvents the stepwise increase in the size of metal (Au) nanoparticles can be achieved.…”

“…Gold nanoparticles (AuNPs) have been under wide range of utilization since last couple of decade, especially industrial and pharmaceutical/biomedical elds. 1,[9][10][11][12] Recently, these ideal sized metal (Au) nanoparticles have been used in various technological and biomedical applications such as organic photovoltaic, 9 drug delivery systems (DDSs), 10 sensory probes, 11,12 pharmaceutical and therapeutic applications, catalysis and electronic conductors. [11][12][13][14] The size, shape and morphology/geometry of gold nanoparticles are changeable by tuning their physical and chemical properties.…”

“…1,[9][10][11][12] Recently, these ideal sized metal (Au) nanoparticles have been used in various technological and biomedical applications such as organic photovoltaic, 9 drug delivery systems (DDSs), 10 sensory probes, 11,12 pharmaceutical and therapeutic applications, catalysis and electronic conductors. [11][12][13][14] The size, shape and morphology/geometry of gold nanoparticles are changeable by tuning their physical and chemical properties. [1][2][3][4][5]15 These polar solvents propagate the interactions between the solvent molecules and metal particles to reduce the size and change the surface chemistry of nanoparticles through the aggregation and this aggregation can be avoided through the sonication methods.…”