Tumor hypoxia is a well-recognized driver of resistance to traditional cancer therapies such as chemotherapy and radiation therapy. We describe development of a new nanoconstruct composed of gold nanorods (GNRs) conjugated to carbonic anhydrase IX (CAIX) antibody that specifically binds to CAIX, a biomarker of hypoxia, to facilitate targeting tumor hypoxic areas for focused photothermal ablation. Physicochemical characterization studies confirmed the size, shape, monodispersity, surface charge, and serum stability of the GNRs. Enzyme-linked immunosorbent assays and cellular binding and uptake studies confirmed successful conjugation of antibody to the GNRs and specificity for CAIX. Near-infrared irradiation of CAIX-overexpressing cells treated with GNR/anti-CAIX resulted in significantly higher cell death than cells treated with control GNRs. In vivo biodistribution studies using hyperspectral imaging and inductively coupled plasma mass spectrometry confirmed intravenous administration results not only in greater accumulation of GNR/anti-CAIX in tumors than control GNRs but also greater penetration into hypoxic areas of tumors. Near-infrared ablation of these tumors showed no tumor regression in the sham-treated group, regression but recurrence in the non-targeted-GNR group, and complete tumor regression in the targeted-GNR group. GNR/anti-CAIX nanoconstructs show promise as hypoxia targeting and photothermal ablation agents for cancer treatment.

Purpose Itraconazole (ITZ) is a synthetic triazole antifungal agent, which is widely used for treatment and prevention of fungal infections. The purpose of this study is to develop ITZ-loaded poly(lactic-co-glycolic acid) (PLGA) nanospheres (PLGA-ITZ-NS) as a new sustained-release formulation for intravenous ITZ administration. Materials and methods PLGA-ITZ-NS were prepared by a nanoprecipitation method and optimized by modifying the surfactant poloxamer 188 concentration and PLGA:ITZ ratio. Their physicochemical properties, including size, zeta potential, external morphology and encapsulation efficiency, were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and high performance liquid chromatography (HPLC). The effect of the different selected lyoprotectants with various concentrations on NS particles size and surface charge were also assessed. Rapid and sensitive HPLC and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed to determine ITZ concentrations in formulation and in rat plasma, respectively. Pharmacokinetics of the optimum PLGA-ITZ-NS formulation was compared with the former commercial Sporanox® injection formulation using rats as the animal model. Noncompartmental pharmacokinetic parameters were obtained by WinNonlin® software. Results Optimal PLGA-ITZ-NS had a mean particle size of about 200 nm with a high homogeneity (polydispersity index ≈0.2), favorable zeta potential (approximately −20 to −30 mV) and encapsulation efficiency (72%). In addition, 2% w/v sucrose was selected as a lyoprotectant for NS freeze-drying. The newly developed LC-MS/MS assay was validated and found to be accurate and precise. The in vivo study showed that the NS formulation has a similar systemic bioavailability to Sporanox® while providing a sustained plasma level (> 100 ng/mL) for up to 24 hours after intravenous administration. Conclusion Our newly developed PLGA-ITZ-NS has shown great sustained release and comparable bioavailability with Sporanox®, therefore having the potential to be an alternative injectable formulation of ITZ.

MJC13, a novel FKBP52 targeting agent, has potential use for the treatment of castrate-resistant prostate cancer. The purpose of this work was to develop a solution formulation of MJC13, and obtain its efficacy profile in a human prostate cancer xenograft mouse model. Preformulation studies were conducted to evaluate the physicochemical properties. Co-solvent systems were evaluated for aqueous solubility and tolerance. A human prostate cancer xenograft mouse model was established by growing 22Rv1 prostate cancer cells in C.B-17 SCID mice. The optimal formulation was used to study the efficacy of MJC13 in this preclinical model of castrate-resistant prostate cancer. We found that MJC13 was stable (at least for 1 month), very lipophilic (logP = 6.49), poorly soluble in water (0.28 μg/mL), and highly plasma protein bound (> 98%). The optimal formulation consisting of PEG 400 and Tween 80 (1:1, v/v) allowed us to achieve a MJC13 concentration of 7.5 mg/mL, and tolerated an aqueous environment. After twice weekly intratumoral injection with 10 mg/kg MJC13 in this formulation for 4 consecutive weeks, tumor volumes were significantly reduced compared to vehicle-treated controls.

γ-Tocotrienol has attracted great attention due to its multiple health benefits. This study developed and validated a simple, specific, sensitive and reliable LC/MS/MS method to analyze γ-tocotrienol in rat plasma. Plasma samples (50 µL) were extracted with internal standard solution (25 ng/mL of itraconazole) in acetonitrile (200 µL) with an average recovery of 44.7% and an average matrix effect of −2.9%. The separation of γ-tocotrienol and internal standard from the plasma components was achieved with a Waters XTerra® MS C18 column with acetonitrile/water as mobile phases. Analysis was performed under positive ionization electrospray mass spectrometer via the multiple reaction monitoring. The standard curve was linear over a concentration range of 10 – 1000 ng/mL with correlation coefficient values > 0.997. The method was validated with intra- and inter-day accuracy (relative error) ranged from 1.79 to 9.17% and 2.16 to 9.66%, respectively, and precision (coefficient of variation) ranged from 1.94 to 9.25% and 2.37 to 10.08%, respectively. The short-term disability, freeze-thaw stability and the processed sample stability tests were performed. This method was further applied to analyze γ-tocotrienol plasma concentrations in rats at various time points after administration of a 2 mg/kg single intravenous dose, and a pharmacokinetic profile was successfully obtained.

PURPOSE: Hypoxia is a common feature of solid tumors that occurs across a wide variety of malignancies and significantly reduces tumor sensitivity to radiation and chemotherapy. Carbonic anhydrase IX (CAIX), an extracellular protein that is overexpressed in hypoxic zones within many human tumors, has emerged as a promising biomarker. To pursue focal targeted therapy of tumor hypoxia, we prepared and characterized a novel nanoconstruct composed of gold nanorods (GNR), which show superior capability to assist tumor photothermal ablation, and anti-CAIX antibody (CAIX-Ab), which binds specifically to CAIX. EXPERIMENTS: GNR with aspect ratio (length 24 nm to width 8nm) of 3 were conjugated to CAIX-Ab through bifunctional polyethylene glycol (PEG). The conjugates were characterized by monitoring the absorption peak shift as well as size and zeta potential changes for each step of the preparation. The stabilities of the GNR, GNR-PEG and GNR/CAIX-Ab were challenged by 1X PBS. The binding affinity and specificity of the GNR/CAIX-Ab were evaluated with ELISA using CAIX protein and cell adhesion assay using HT29 human colorectal cells (overexpresing CAIX) and NIH-3T3 cells (no expressing CAIX, control). The photothermal cell ablation was performed on HT29 cells treated with medium (control), GNR-PEG (control) and GNR/CAIX-Ab. RESULTS: Obvious shifts of the absorption peaks of GNR at the NIR region and particle size and surface charge changes suggested the success of the conjugation. After challenging by 1XPBS, bare GNR formed aggregations and lost the peak at 745 nm while GNR-PEG and GNR/CAIX-Ab remained stable as their absorption peaks around 750 nm were preserved. This is an important finding suggesting that our conjugated GNR will be stable for in vivo work. From the sandwich ELISA study, we obtained a standard linear curve of absorbance vs. CAIX-Ab concentration with R2 of 0.997 and linear curve of absorbance vs. GNR/CAIX-Ab concentration with R2 of 0.999. And we found that the negative control GNR-PEG had no binding to the CAIX protein. We calculated the number of CAIX-Ab per GNR to be 1.47 ± 0.2. In cell adhesion assay, neither GNR-PEG nor GNR/CAIX-Ab had detectable binding to 3T3 cells; but with HT29 cells, GNR-PEG still showed no binding while GNR/CAIX-Ab bound specifically and avidly to the cells. Photothermal ablation of HT29 cells revealed complete cell death after treatment of GNR/CAIX-Ab while the cells remained alive when treated with medium or GNR-PEG. CONCLUSION: These findings suggested that GNR/CAIX-Ab is a stable and effective nanoconstruct appropriate for focal targeting and photothermal ablation of tumor hypoxia. This new photothermal therapy has the great potential as an alternative or complementary approach for standard cancer treatment to eliminate residual or recurrent tumor cells, especially within the hypoxic areas that are resistant to traditional therapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2889. doi:1538-7445.AM2012-2889