Background and Aims: Acute heart failure (AHF) promotes inflammatory activation, which is associated with worse outcomes. Colchicine has proven effective in other cardiovascular conditions characterized by inflammatory activation, but has never been evaluated in the setting of AHF. Methods: This multicenter, randomized, double-blind, and placebo-controlled trial included patients with AHF, requiring ≥40 mg of intravenous furosemide, regardless of their left ventricular ejection fraction (LVEF) and inpatient or outpatient setting. Patients were randomized within the first 24 h of presentation to receive either colchicine or placebo, with loading dose of 2 mg, followed by 0.5 mg every 12 h for 8 weeks. Results: A total of 278 patients [median age 75 years, LVEF 40%, baseline N-terminal pro-B-type natriuretic peptide (NT-proBNP) 4262 pg/mL] were randomized to colchicine (n = 141) or placebo (n = 137). The primary endpoint, the time-averaged reduction in NT-proBNP levels at 8 weeks, did not differ between the colchicine group [−62.2%, 95% confidence interval (CI) −68.9% to −54.2%] and the placebo group (−62.1%, 95% CI −68.6% to −54.3%) (ratio of change 1.0). The reduction in inflammatory markers was significantly greater with colchicine: ratio of change 0.60 (P < .001) for C-reactive protein and 0.72 (P = .019) for interleukin-6. No differences were found in new worsening heart failure episodes (14.9% with colchicine vs. 16.8% with placebo, P = .698); however, the need for intravenous furosemide during follow-up was lower with colchicine (P = .043). Diarrhea was slightly more common with colchicine, but it did not result in differences in medication withdrawal (8.5% vs. 8.8%). Conclusions: Colchicine was safe and effective in reducing inflammation in patients with AHF; however, colchicine and placebo exhibited comparable effects on reducing NT-proBNP and preventing new worsening heart failure events.
In recent years, silk fibroin nanoparticles (SFNs) have been consolidated as drug delivery systems (DDSs) with multiple applications in personalized medicine. The design of a simple, inexpensive, and scalable preparation method is an objective pursued by many research groups. When the objective is to produce nanoparticles suitable for biomedical uses, their sterility is essential. To achieve sufficient control of all the crucial stages in the process and knowledge of their implications for the final characteristics of the nanoparticles, the present work focused on the final stage of sterilization. In this work, the sterilization of SFNs was studied by comparing the effect of different available treatments on the characteristics of the nanoparticles. Two different sterilization methods, gamma irradiation and autoclaving, were tested, and optimal conditions were identified to achieve the sterilization of SFNs by gamma irradiation. The minimum irradiation dose to achieve sterilization of the nanoparticle suspension without changes in the nanoparticle size, polydispersity, or Z-potential was determined to be 5 kiloGrays (kGy). These simple and safe methods were successfully implemented for the sterilization of SFNs in aqueous suspension and facilitate the application of these nanoparticles in medicine.
Silk fibroin nanoparticles (SFN) have become a promising tool in drug delivery systems due to their physicochemical characteristics. SFN have shown their outstanding properties as an active vehicle for polyphenols, enhancing their antioxidant and anti-inflammatory effects on macrophages; therefore, it becomes necessary to have an easy, reproducible and scalable production method. In order to improve the production of nanoparticles, we performed direct precipitation of non-dialyzed silk fibroin solutions and evaluated the reproducibility of the method using dynamic light scattering. We also studied the loading efficiency of three different natural polyphenols using propylene glycol as a solvent. The loaded nanoparticles were fully characterized and used to treat human macrophage cells to assess the anti-inflammatory activity of these nanoparticles. The measured hydrodynamic characteristics of the SFN and the overall yield of the process showed that the new preparation method is highly reproducible and repeatable. Thus, we not only present a new scalable method to prepare silk nanoparticles but also how to improve the loading of natural polyphenolic compounds to the SFN, as well as the important anti-inflammatory effects of these loaded nanoparticles in a cell model of human macrophage cells.
Nuclear imaging is a highly sensitive and noninvasive imaging technique that has become essential for medical diagnosis. The use of radiolabeled nanomaterials capable of acting as imaging probes has shown rapid development in recent years as a powerful, highly sensitive, and noninvasive tool. In addition, quantitative single-photon emission computed tomography (SPECT) images performed by incorporating radioisotopes into nanoparticles (NPs) might improve the evaluation and the validation of potential clinical treatments. In this work, we present a direct method for [99mTc]Tc-radiolabeling of FITC-tagged silk fibroin nanoparticles (SFN). NPs were characterized by means of dynamic light scattering and scanning electron microscopy. In vitro studies were carried out, including the evaluation of stability in biological media and the evaluation of hemocompatibility and genotoxicity using the cytokinesis block micronucleus (CBMN) assay. The radiolabeling method was reproducible and robust with high radiolabeling efficiency (∼95%) and high stability in biological media. Hydrodynamic properties of the radiolabeled NPs remain stable after dual labeling. The interaction of SFN with blood elicits a mild host response, as expected. Furthermore, CBMN assay did not show genotoxicity induced by [99mTc]Tc-FITC-SFN under the described conditions. In conclusion, a feasible and robust dual-labeling method has been developed whose applicability has been demonstrated in vitro, showing its value for further investigations of silk fibroin NPs biodistribution in vivo.
To avoid adverse effects during the administration of [123I] meta-iodobenzylguanidine (MIBG), infusion of the drug that has been previously diluted is proposed. Stability of [123I] MIBG in sodium chloride solutions is studied, looking for incompatibilities in the formulation. Stability was tested on the basis of the percentage of free [123I] iodide on solid-phase extraction. No increase in percentages of free [123I] iodide was found in diluted and undiluted samples over time (P>0.05). Intravenous saline infusion of [123I] MIBG could be a useful tool for controlling the administration rate, minimizing the side effects and lowering the exposure of the staff to ionizing radiation.
Gastric emptying scintigraphy provides a physiologic, noninvasive, and quantitative measurement of gastric emptying. Consensus guidelines recommended a standardized meal that consisted of an egg substitute equal to two whole eggs labeled with sulphur colloid ([99mTc]Tc-SC), two slices of bread, jam, and 120 mL of water. Previous studies reported the use of commercial liquid nutrient meal (LNM) as a suitable meal for patients with egg allergy. Our work proposes an alternative recipe based on cooking commercial LNM as a pancake, and evaluates the stability of binding of several radiopharmaceuticals in simulated gastric medium, concluding that [99mTc]Tc-MAA binds to LNM pancakes in percentages ≥90%, similar to scrambled eggs standardized meal, so that [99mTc]Tc-MAA-LNM in pancakes could be a good alternative for patients who have allergies to eggs, intolerance to LNM or difficulties for finishing the entire standard meal, as for instance pediatric patients for whom pancakes should be an attractive recipe.