carbocyanines and perflexane

Drug delivery to a tumor site with an insufficient microvascular network remains a challenge due to the size preference for transport in terms of circulation and distribution. In this work, an integrated nano-therapeutic parcel disintegrable by a photoacoustic shockwave was developed. Nano-therapeutic particles with red absorbance are packaged into a larger parcel to generate a longer circulation half-life and improved accumulation in tumor tissue. Pulse-laser irradiation is absorbed by the nanoparticles and it generates a photoacoustic shockwave. This triggers a liquid-gas phase transition of the nano-parcel, leading to the high-efficiency release of smaller nanoparticles, thus achieving excellent therapeutic diffusion with improved uniformity. This results in a highly effective therapeutic effect, as demonstrated with both in vitro and in vivo tumor models. Compared to previously reported work, this approach has the distinctive advantage of precisely controllable therapeutic release that is independent of the physiological environment in the tumor and it is less limited than a UV-based release mechanism. In addition, the concept of photoacoustic shockwave-based nanoparticle release can be extended over a wide wavelength range, including microwaves, to match specific needs and achieve optimal therapeutic depth. The results demonstrate that the proposed strategy holds great potential for improved tumor therapy efficacy.

Topics: Animals; Apoptosis; Carbocyanines; Cell Line, Tumor; Coordination Complexes; Dendrimers; Fluorocarbons; Humans; Membrane Potential, Mitochondrial; Mice; Mice, Inbred BALB C; Mice, Nude; Microwaves; Nanoparticles; Neoplasms; Photoacoustic Techniques; Platinum; Prodrugs; Tissue Distribution; Transplantation, Heterologous

Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work.

Topics: Acoustics; Breast Neoplasms; Carbocyanines; Contrast Media; Female; Fluorescent Dyes; Fluorocarbons; Humans; Lactic Acid; Lasers; MCF-7 Cells; Microbubbles; Microscopy, Fluorescence; Models, Biological; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Spheroids, Cellular; Ultrasonography, Mammary; Volatilization