Carborane bearing pullulan nanogel-boron oxide nanoparticle hybrid for boron neutron capture therapy.

Boron neutron capture therapy shows is a promising approach to cancer therapy, but the delivery of effective boron agents is challenging. To address the requirements for efficient boron delivery, we used a hybrid nanoparticle comprising a carborane = bearing pullulan nanogel and hydrophobized boron oxide nanoparticle (HBNGs) enabling the preparation of highly concentrated boron agents for efficient delivery. The HBNGs showed better anti-cancer effects on Colon26 cells than a clinically boron agent, L-BPA/fructose complex, by enhancing the accumulation and retention amount of the boron agent within cells in vitro. The accumulation of HBNGs in tumors, due to the enhanced permeation and retention effect, enabled the delivery of boron agents with high tumor selectivity, meeting clinical demands. Intravenous injection of boron neutron capture therapy (BNCT) using HBNGs decreased tumor volume without significant body weight loss, and no regrowth of tumor was observed three months after complete regression. The therapeutic efficacy of HBNGs was better than that of L-BPA/fructose complex. BNCT with HBNGs is a promising approach to cancer therapeutics.

Drug-Loaded Biocompatible Chitosan Polymeric Films with Both Stretchability and Controlled Release for Drug Delivery.

Chitosan is a natural polysaccharide with the advantageous qualities of biocompatibility and biodegradability, and it has recently been spotlighted as a soft material for a sustainable society. Advantages such as these are in demand for application in various biomaterials. Although extensive studies have been conducted on the preparation of chitosan films, overcoming the problems of weak mechanical properties remains a significant barrier. In the present study, we developed stretchable doxorubicin-loaded biocompatible chitosan films by adding acetic acid in controlled concentrations. The stretchable properties of doxorubicin-loaded chitosan film at various concentrations of acetic acid were measured. Elongation to the point of breakage reached 27% with a high concentration of acetic acid, which could be described as high stretchability. The release ratio of doxorubicin from chitosan film reached 70% with a high acetic acid concentration. The cytotoxicity of doxorubicin-loaded chitosan films was measured, and cancer spheroids had completely collapsed after 7 days. According to the results of skin permeability testing, use of the doxorubicin-loaded chitosan film is a plausible choice for a drug sealant.

Theranostic Agent Combining Fullerene Nanocrystals and Gold Nanoparticles for Photoacoustic Imaging and Photothermal Therapy.

Developing photoactivatable theranostic platforms with integrated functionalities of biocompatibility, targeting, imaging contrast, and therapy is a promising approach for cancer diagnosis and therapy. Here, we report a theranostic agent based on a hybrid nanoparticle comprising fullerene nanocrystals and gold nanoparticles (FGNPs) for photoacoustic imaging and photothermal therapy. Compared to gold nanoparticles and fullerene crystals, FGNPs exhibited stronger photoacoustic signals and photothermal heating characteristics by irradiating light with an optimal wavelength. Our studies demonstrated that FGNPs could kill cancer cells due to their photothermal heating characteristics in vitro. Moreover, FGNPs that are accumulated in tumor tissue via the enhanced permeation and retention effect can visualize tumor tissue due to their photoacoustic signal in tumor xenograft model mice. The theranostic agent with FGNPs shows promise for cancer therapy.