The Study of Photoacoustic Effect of Liposome with Encapsulated GNPs

The purpose of the proposal, from Aug. 2013 to July 2014, is to study the photoacoustic (PA) effect of liposomes with encapsulated gold nanoparticles (GNPs) or gold nanorods (GNRs), as irradiated by pulsed Nd: YAG laser. The synthesis method (thin-film hydration method with sonication method) will be used to prepare the liposomes with encapsulated GNPs or GNRs. Three types of liposome-GNPs will be synthesized: encapsulated GNPs, loaded GPs and surface attached GNPs. A filter (polycarbonate membrane) with a specific pore size will be used to control the size of liposome. In addition, the synthesized liposome-GNPs will be characterized by ICP-OES and UV-NIR spectrometer. Using the dark-field microscopy, the morphologies of the bigger liposome with encapsulated GNPs before and after irradiation will be analyzed. Moreover, the hyperspectral dark-field microscopy will be used to measure the scattering spectrum of each liposome-GNPs. We will develop two photoacoustic spectroscopies using ultrasonic transducer to detect the PA signals emitted from the cavitation of the transient plasmonic nanobubbles (PNBs) around GNP, as the liposomes-GNPs are irradiated by pulsed laser. These transient PNBs around each GNP could damage the liposome. The intensity of PA signal, detected by a broadband ultrasonic transducer, will be correlated to the number of the encapsulated GNPs. The results will be useful to the application of liposome with loaded GNPs for drug delivery and release system. For the liposome with GNRs, the tunable infrared wavelength of Nd: YAG laser with OPO will be used. The size of the liposome will be measured by dark-field microscopy, and the dose of GNPs will be measured quantitatively by ICP-OES. The cells (macrophage) cultured with a medium containing liposome with encapsulated GNPs will be prepared. The dose of GNPs internalized by cells will be measured to compare with that of the control incubated with a GNPs-medium without liposome. After that, the photodamage of these cells irradiated by the pulsed laser will be studied. In addition, the behavior of laser induced microbubble (LIMB) in the colloid of liposome-GNRs will also be investigated. The mechanism of LIMB is caused the cavitation due to the optical dielectric breakdown at the focus in the medium, which is different from that of LINB. The passive and active ultrasonic measurements will be used to study the lifetime and dynamic formation of a LIMB, which is related to the concentration and aggregation of GNPs.

Project ID:PB10207-1802
External Project ID:NSC102-2221-E182-049