Cryoablation of renal tumors: long-term follow-up from a multicenter experience

Purpose: To retrospectively investigate long-term outcomes of renal cryoablation from a multicenter database. Methods: 338 patients with 363 renal tumors underwent cryoablation in 4 centers in North-Eastern Italy. 340/363 tumors (93.7%) were percutaneously treated with CT guidance. 234 (68.8%) were treated after conscious sedation, 76 (22.3%) under local lidocaine anesthesia only and 30 (8.8%) under general anesthesia. Treatment efficacy and complication rate considered all procedures. Oncologic outcomes considered a subset of 159 patients with 159 biopsy proven renal cell carcinoma. Results: Mean tumor size was 2.53 cm. Technical success was achieved in 355/363 (97.8%) treatments. Treatment efficacy after the first treatment was achieved in 348/363 (95.9%) tumors. Statistical analysis revealed a significant lower treatment efficacy for ASA score >3, Padua score >8, tumor size >2.5 cm, use of >2 cryoprobes, presence of one single kidney. In the subset of 159 patients, recurrence-free survival rates were 90.5% (95% CI 83.0%, 94.9%) at 3 years and 82.4% (95% CI 72.0%, 89.4%) at 5 years; overall survival rates were 96.0% (95% CI 90.6%, 98.3%) at 3 years and 91.0% (95% CI 81.7%, 95.7%) at 5 years; no patient in this subset developed metastatic disease. Clavien-Dindo >1 complications were recorded in 14/369 procedures (3.8%) and were related to age >70 years, tumor size >4 cm and use of >2 cryoprobes. Conclusion: Cryoablation performed across four different centers in a large cohort of predominantly small renal tumors showed that this technique provides good recurrence-free survival rates and overall survival rates at three- and five-year with very low major complications rate

Delivery of selenium using chitosan nanoparticles: Synthesis, characterization, and antioxidant and growth effects in Nile tilapia (Orechromis niloticus)

This study aimed to elucidate the effects of selenium-loaded chitosan nanoparticles used as a dietary supplement on Nile tilapia (Oreochromis niloticus) antioxidant and growth responses. First, chitosan-based nanoparticles containing selenium (Se) were synthesized using the ionotropic gelation method and their physicochemical characteristics, controlled release profile, and antioxidant activity properties were investigated. Thereafter, the effects on glutathione peroxidase and antioxidant activities (by radical scavenging activity), growth, and whole-body composition of Nile tilapia were evaluated when they were fed with Se-loaded chitosan nanoparticles and compared with other selenium dietary supplements. Se-loaded chitosan nanoparticles showed high entrapment efficiency (87%), spherical shape, smooth surface, and broad size distribution. The controlled release of Se consisted of an initial burst followed by a gradual release over 48 h. Se-loaded nanoparticles presented significantly higher antioxidant activity compared to free Se. A 60-day feeding trial was conducted to compare the effects of supplementing different dietary Se sources, including selenomethionine (as organic source), sodium selenite (as inorganic source), and Se-loaded chitosan nanoparticles (Se-Nano and Se-Nano x1.5) on antioxidant and growth responses of Nile tilapia. A basal diet without Se supplementation was used as the control. The dietary supplementations with different Se sources (free and encapsulated selenium) lead to significant improvements in final weight and feed efficiency of Nile tilapia fingerlings. However, dietary treatments did not affect whole-body protein and lipid content. Diets containing Se-Nano and Se-Nano x1.5 were more effective than sodium selenite and selenomethionine in preventing oxidative stress and improving antioxidant activity in Nile tilapia. Overall, Se-loaded nanoparticles presented a great potential as an efficient source for delivering dietary Se to Nile tilapia, directly affecting the growth performance, feed efficiency, oxidative stress, and antioxidant activity of this species.This article is published as Araujo, Juliana M., Rodrigo Fortes-Silva, Cícero C. Pola, Fernando Y. Yamamoto, Delbert M. Gatlin III, and Carmen L. Gomes. "Delivery of selenium using chitosan nanoparticles: Synthesis, characterization, and antioxidant and growth effects in Nile tilapia (Orechromis niloticus)." PLoS One 16, no. 5 (2021): e0251786. DOI: 10.1371/journal.pone.0251786. Copyright 2021 Araujo et al. Attribution 4.0 International (CC BY 4.0). Posted with permission

Biomimetic nanosensors for measuring pathogenic bacteria in complex food matrices (Conference Presentation)

Listeria monocytogenes and Salmonella spp. are among the most common cause of foodborne illnesses that negatively affect consumers’ health and food producers’ finances and credibility. Techniques used to detect pathogens (e.g., total viable counts, polymerase chain reaction, and enzyme-linked immunosorbent assays) are time consuming and costly as they require laboratory conditions with trained personnel. To meet this demand without compromising public health concerns, highly sensitive and rapid sensors are needed in food processing facilities for pathogen detection to reduce cost and holding time for food products. Ideally, these sensors should be small, label-free, low cost, portable, and highly sensitive/selective. This study describes some recent approaches for creating biomimetic sensors by optimizing the bacteria capture efficiency without the need for pre-concentration and pre-labeling steps. Two in-field biosensors were developed for measuring pathogenic bacteria in food matrices. The first example consists of pH-responsive polymer nanobrushes embedded with platinum nanoparticles platform with enhanced limit of detection and sensitivity for quantification of Listeria monocytogenes in fresh vegetables. A new approach using a one-step metal and polymer simultaneous deposition was tested using two pH-sensitive polymers and a thiol-terminated DNA aptamer selective to surface protein internalin A of Listeria monocytogenes. The second example demonstrates development of pathogenic biosensors for chicken broth using antibodies and DNA aptamers selective to Salmonella Typhimurium adsorbed to aerosolized graphene interdigitated electrodes (IDEs). Devices were printed in polyimide tape and aerosolized graphene was thermally annealed. The integrity of the substrate was analyzed and the nano-biosensors were characterized for topography, pH-actuation, graphene content, and electroactivity using electron microscopy, cyclic voltammetry, and multiple spectroscopy techniques (Raman, Fourier-transform infrared, and electrochemical impedance). Electrochemical impedance spectroscopy was used to evaluate the signal and determine the limit of detection by evaluating the change in charge transfer resistance. The nano-biosensors have a detection limit of approximately 5 CFU.mL-1, and a response time of approximately 17 minutes (15 minutes incubation period). The pH-sensitive nanobrushes and graphene-based biosensors have a selectivity for the target pathogen of approximately 95% in vegetable and chicken broth, respectively. The designed biosensor platform showed great potential to replace current standard methods used by the food industry for rapid foodborne pathogenic bacteria detection

Study of chemical compound spatial distribution in biodegradable active films using NIR hyperspectral imaging and multivariate curve resolution

A study of spatial distribution of the four different plasticizers and sorbic acid incorporated in cellulose acetate biodegradable films using near-infrared hyperspectral imaging (NIR-HSI) and multivariate curve resolution-alternating least squares (MCR-ALS) is presented. A NIR-HSI was acquired for each film. MCR-ALS was applied to generate pure component distribution maps. A repeatability study was performed. The proposed method was able to recover the pure spectra of each film component accurately. The relative concentration vectors obtained by the MCR-ALS were rebuilt in matrices, and it was possible to analyze the homogeneity of the film constituents based on macropixel analysis and homogeneity index. The NIR-HSI imaging showed excellent repeatability. For the first time, a study detailing the distribution of chemical compounds incorporated into entire biodegradable films was possible by using NIR hyperspectral imaging combined with the MCR-ALS method341CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo à Pesquisa Do Estado De Minas Geraissem informaçãosem informação00

Sense–Analyze–Respond–Actuate (SARA) Paradigm: Proof of Concept System Spanning Nanoscale and Macroscale Actuation for Detection of Escherichia coli in Aqueous Media

Foodborne pathogens are a major concern for public health. We demonstrate for the first time a partially automated sensing system for rapid (~17 min), label-free impedimetric detection of Escherichia coli spp. in food samples (vegetable broth) and hydroponic media (aeroponic lettuce system) based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) nanobrushes. This proof of concept (PoC) for the Sense-Analyze-Respond-Actuate (SARA) paradigm uses a biomimetic nanostructure that is analyzed and actuated with a smartphone. The bio-inspired soft material and sensing mechanism is inspired by binary symbiotic systems found in nature, where low concentrations of bacteria are captured from complex matrices by brush actuation driven by concentration gradients at the tissue surface. To mimic this natural actuation system, carbon-metal nanohybrid sensors were fabricated as the transducer layer, and coated with PNIPAAm nanobrushes. The most effective coating and actuation protocol for E. coli detection at various temperatures above/below the critical solution temperature of PNIPAAm was determined using a series of electrochemical experiments. After analyzing nanobrush actuation in stagnant media, we developed a flow through system using a series of pumps that are triggered by electrochemical events at the surface of the biosensor. SARA PoC may be viewed as a cyber-physical system that actuates nanomaterials using smartphone-based electroanalytical testing of samples. This study demonstrates thermal actuation of polymer nanobrushes to detect (sense) bacteria using a cyber-physical systems (CPS) approach. This PoC may catalyze the development of smart sensors capable of actuation at the nanoscale (stimulus-response polymer) and macroscale (non-microfluidic pumping)

The Influence of Intermolecular Interactions between Maleic Anhydride, Cellulose Nanocrystal, and Nisin-Z on the Structural, Thermal, and Antimicrobial Properties of Starch-PVA Plasticized Matrix

On behalf of a circular economy, regular plastics have been replaced by biodegradable packagings. Besides, active films have been applied to improve the shelf-life and quality of foods. In this work, blends were developed using starch as a low-cost natural polymer, mixed with poly(vinyl alcohol) due to its physical-chemical and biodegradable properties. Moreover, maleic anhydride (MaAh), cellulose-nanocrystal (CN), and nisin-z (N-Z) were added, respectively, as a compatibilizer, a mechanical-reinforce, and antimicrobial agents. The thermal stability of the films was analyzed, which blends’ melting temperature occurred around 200–207 °C, and it was influenced by CN, N-Z, and MaAh amounts. N-Z and MaAh acted against S. aureus and P. aeruginosa by compound diffusion (inhibition-halo around 1.85 and 2.18 cm); while S. Choleraesuis and E. coli were inhibited by contact. Therefore, these blends presented the potential to be used as active biodegradable packaging in the food industry