Laser enhancement of cancer cell destruction by photothermal therapy conjugated glutathione (GSH)-coated small-sized gold nanoparticles.

The current study presents the employment of glutathione (GSH)-modified small-sized gold nanoparticles (AuNPs) ~ 3 nm in photothermal therapy (PTT), to evaluate the targeting and the toxic effect of cancer rather than normal cells. GSH is pH-sensitive surfaces that exhibit a fast response to the variation in pH conditions between normal (~ 7.4) and cancer cells (6-6.5). Results showed a considerable toxic impact via GSH-AuNP accumulation in cancer cells by both green and NIR laser irradiation. A proportional relation of cellular death to AuNP concentration, exposure time, and light-to-heat conversion efficiency has been demonstrated. The small-sized GSH-AuNPs represent promising agents for developing the safety issues of photothermal cancer treatment by the selective targeting of cancer rather than normal cells, reducing the NP toxicity by their size overlapping with the renal clearance barrier of kidney filtration (~ 5.5 nm), and promoting the photothermal performance in the NIR region, in which light penetration into deep cancer regions is more interested.

Synthesis and characterization of small-sized gold nanoparticles coated by bovine serum albumin (BSA) for cancer photothermal therapy.

In the present study, small gold nanoparticles <5 nm coated with natural protein Bovine Serum Albumin (BSA) was synthesized and characterized using UV-vis spectrophotometer, Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta potential and scanning electron microscopy (SEM). Three types of cancer cell lines; Rhabdomyosarcoma (RD), Murine fibroblast (L20B) and RAW 264.7 monocyte-macrophage (MQ) were tested and treated by photothermal strategy, in vitro, by conjugating BSA-AuNPs complex of (0.125, 0.25, 0.5 and 1 mg/ml) concentrations with continuous low power laser irradiation, green (532 nm) and near-infrared (NIR) (800 nm) at 0.5, 1, 2 and 3 min, separately. Cytotoxicity effect was determined by MTT assay. The vital impact of photothermal technique has investigated at 1 mg/ml and 3 min irradiation period as identified in RD cell line in comparison with other types; where cytotoxicity more than 74% was reached. Prominent results were demonstrated in the green and NIR region by pH -induced aggregation effect of small nanoparticles inside the cancer cells, which make the small-sized BSA-AuNPs are promising agents for cancer photothermal therapy.