Comparison between Fluorescence Imaging and Elemental Analysis to Determine Biodistribution of Inorganic Nanoparticles with Strong Light Absorption.

Black porous silicon nanoparticles (BPSi NPs) are known as highly efficient infrared light absorbers that are well-suitable for photothermal therapy (PTT) and photoacoustic imaging (PAI). PTT and PAI require a sufficient number of effectively light-absorbing NPs to be accumulated in tumor after intravenous administration. Herein, biodistribution of PEGylated BPSi NPs with different sizes (i.e., 140, 200, and 300 nm in diameter) is investigated after intravenous administration in mice. BPSi NPs were conjugated with fluorescent dyes Cy5.5 and Cy7.5 to track them in vitro and in vivo, respectively. Optical imaging with an in vivo imaging system (IVIS) was found to be an inadequate technique to assess the biodistribution of the dye-labeled BPSi NPs in vivo because the intrinsic strong absorbance of the BPSi NPs interfered fluorescence detection. This challenge was resolved via the use of inductively coupled plasma optical emission spectrometry to analyze ex vivo the silicon content in different tissues and tumors. The results indicated that most of the polyethylene glycol-coated BPSi NPs were found to accumulate in the liver and spleen after intravenous injection. The smallest 140 nm particles accumulated the most in tumors at an amount of 9.5 ± 3.4% of the injected dose (concentration of 0.18 ± 0.08 mg/mL), the amount known to produce sufficient heat for cancer PTT. Furthermore, the findings from the present study also suggest that techniques other than optical imaging should be considered to study the organ biodistribution of NPs with strong light absorbance properties.

Long-term clinical outcome of elderly patients with acute coronary syndrome treated with early percutaneous coronary intervention: Insights from the BASE ACS randomized controlled trial: Bioactive versus everolimus-eluting stents in elderly patients.

BACKGROUND: The BASE ACS trial demonstrated an outcome of titanium-nitride-oxide-coated bioactive stents (BAS) that was non-inferior to everolimus-eluting stents (EES) in patients presenting with acute coronary syndrome (ACS). We performed a post hoc analysis of elderly versus non-elderly patients from the BASE ACS trial. METHODS: We randomized 827 patients (1:1) presenting with ACS to receive either BAS or EES. The primary endpoint was major adverse cardiac events (MACE): a composite of cardiac death, non-fatal myocardial infarction (MI), or ischemia-driven target lesion revascularization (TLR). Follow-up was planned at 12months and yearly thereafter for up to 7years. Elderly age was defined as ≥65years. RESULTS: Of the 827 patients enrolled in the BASE ACS trial, 360 (43.5%) were elderly. Mean follow-up duration was 4.2±1.9years. MACE was more frequent in elderly versus younger patients (19.7% versus 12.0%, respectively, p=0.002), probably driven by more frequent cardiac death and non-fatal MI events (5.3% versus 1.5%, and 9.7% versus 4.5%, p=0.002 and p=0.003, respectively). The rates of ischemia-driven TLR were comparable (p>0.05). In propensity score-matched analysis (215 pairs), only cardiac death was more frequent in elderly patients (6% versus 1.4%, respectively, p=0.01). Diabetes independently predicted both MACE and cardiac death in elderly patients. CONCLUSIONS: Elderly patients treated with stent implantation for ACS had worse long-term clinical outcome, compared with younger ones, mainly due to a higher death rate.