Recent studies Photothermal therapy

1 recent studies

1.1 gold nanorods (aunr)
1.2 gold nanoshells
1.3 graphene , graphene oxide

recent studies
gold nanorods (aunr)

huang et al. investigated feasibility of using gold nanorods both cancer cell imaging photothermal therapy. authors conjugated antibodies (anti-egfr monoclonal antibodies) surface of gold nanorods, allowing gold nanorods bind malignant cancer cells (hsc , hoc malignant cells). after incubating cells gold nanorods, 800 nm ti:sapphire laser used irradiate cells @ varying powers. authors reported successful destruction of malignant cancer cells, while nonmalignant cells unharmed.

when aunp exposed nir light, oscillating electromagnetic field of light causes free electrons of aunp collectively coherently oscillate. changing size , shape of aunp, changes wavelength gets absorbed. desired wavelength between 700-1000 nm because biological tissue optically transparent @ these wavelengths. while aunp properties sensitive change in shape , size, au nanorods properties extremely sensitive change in of dimensions regarding length , wide or aspect ratio. when light shown on metal np, np forms dipole oscillation along direction of electric field. when oscillation reaches maximum, frequency called surface plasmon resonance (spr). aunr have 2 spr spectrum bands: 1 in nir region caused longitudinal oscillation tends stronger longer wavelength , 1 in visible region caused transverse electronic oscillation tends weaker shorter wavelength. spr characteristics account increase in light absorption particle. aunr aspect ratio increases, absorption wavelength redshifted , light scattering efficiency increased. electrons excited nir lose energy after absorption via electron-electron collisions, , these electrons relax down, energy released phonon heats environment of aunp in cancer treatments cancerous cells. process observed when laser has continuous wave onto aunp. pulsed laser light beams results in aunp melting or ablation of particle. continues wave lasers take minutes rather single pulse time pulsed laser, continues wave lasers able heat larger areas @ once.

gold nanoshells

loo et al. investigated gold nanoshells, coating silica nanoparticles thin layer of gold. authors conjugated antibodies (anti-her2 or anti-igg) these nanoshells via peg linkers. after incubation of skbr3 cancer cells gold nanoshells, 820 nm laser used irradiate cells. cells incubated gold nanoshells conjugated specific antibody (anti-her2) damaged laser. category of gold nanoshells gold layer on liposomes, soft template. in case, drug can encapsulated inside and/or in bilayer , release can triggered laser light.

graphene , graphene oxide

yang et al. demonstrated viability of graphene photothermal therapy in 2010 in vivo mice models. 808 nm laser @ power density of 2 w/cm used irradiate tumor sites on mice 5 minutes. noted authors, power densities of lasers used heat gold nanorods range 2 4 w/cm. thus, these nanoscale graphene sheets require laser power on lower end of range used gold nanoparticles photothermally ablate tumors.

in 2012, yang et al. incorporated promising results regarding nanoscale reduced graphene oxide reported robinson et al. in vivo mice study. therapeutic treatment used in study involved use of nanoscale reduced graphene oxide sheets, identical ones used robinson et al. (but without active targeting sequences attached). nanoscale reduced graphene oxide sheets irradiated in order destroy targeted tumors. notably, required power density of 808 nm laser reduced 0.15 w/cm, order of magnitude lower required power densities. study demonstrates higher efficacy of nanoscale reduced graphene oxide sheets compared both nanoscale graphene sheets , gold nanorods.