A Single-Blind Study Evaluating the Efficacy of Gold Nanoparticle Photothermal-Assisted Liposuction in an Ex Vivo Human Tissue Model.

BACKGROUND: Liposuction is one of the most performed cosmetic surgery procedures. In a previously reported study, gold-nanoparticle (GNP) laser-assisted liposuction (NanoLipo) was shown to improve procedure parameters and outcomes in a porcine model. OBJECTIVES: An ex vivo human liposuction model was developed to assess the ease, efficacy, and outcomes of NanoLipo, and to further explore its mechanism of action in facilitating liposuction. METHODS: NanoLipo was compared to a control without GNPs in sets of fresh, nonperfused, anatomically symmetric, matched tissue specimens from 12 patients. A subset of three experiments was performed under single-blinded conditions. Intraoperative assessments included lipoaspirate volume, percentage of free oil, ease of removal, and temperature rise. Specimens were palpated, visualized for evenness, and graded with and without skin. Postoperative assessment included viability staining of the lipoaspirate and remaining tissues. Microcomputed tomography was used to assess the distribution of infused GNPs within the tissues. RESULTS: NanoLipo consistently removed more adipose tissue with more liberated triglycerides compared to control. NanoLipo specimens were smoother, thinner, and had fewer and smaller irregularities. Infused solutions preferentially distributed between fibrous membranes and fat pearls. After NanoLipo, selective structural-tissue disruptions, indicated by loss of metabolic activity, were observed. Thus, NanoLipo likely creates a bimodal mechanism of action whereby fat lobules are dislodged from surrounding fibro-connective tissue, while lipolysis is simultaneously induced. CONCLUSIONS: NanoLipo showed many advantages compared to control under blinded and nonblinded conditions. This technology may be promising in facilitating fat removal.

Review of the progress toward achieving heat confinement-the holy grail of photothermal therapy.

Photothermal therapy (PTT) involves the application of normally benign light wavelengths in combination with efficient photothermal (PT) agents that convert the absorbed light to heat to ablate selected cancers. The major challenge in PTT is the ability to confine heating and thus direct cellular death to precisely where PT agents are located. The dominant strategy in the field has been to create large libraries of PT agents with increased absorption capabilities and to enhance their delivery and accumulation to achieve sufficiently high concentrations in the tissue targets of interest. While the challenge of material confinement is important for achieving "heat and lethality confinement," this review article suggests another key prospective strategy to make this goal a reality. In this approach, equal emphasis is placed on selecting parameters of light exposure, including wavelength, duration, power density, and total power supplied, based on the intrinsic properties and geometry of tissue targets that influence heat dissipation, to truly achieve heat confinement. This review highlights significant milestones researchers have achieved, as well as examples that suggest future research directions, in this promising technique, as it becomes more relevant in clinical cancer therapy and other noncancer applications.