Green Synthesis and Antiproliferative Activity of Gold Nanoparticles of a Controlled Size and Shape Obtained Using Shock Wave Extracts from Amphipterygium adstringens.

In this study, green chemistry was used as a tool to obtain gold nanoparticles using Amphipterygium adstringens extracts as a synthesis medium. Green ethanolic and aqueous extracts were obtained using ultrasound and shock wave-assisted extraction. Gold nanoparticles with sizes ranging between 100 and 150 nm were obtained with ultrasound aqueous extract. Interestingly, homogeneous quasi-spherical gold nanoparticles with sizes between 50 and 100 nm were achieved with shock wave aqueous-ethanolic extracts. Furthermore, 10 nm gold nanoparticles were obtained by the traditional methanolic macerate extraction method. The physicochemical characteristics, morphology, size, stability, and Z potential of the nanoparticles were determined using microscopic and spectroscopic techniques. The viability assay in leukemia cells (Jurkat) was performed using two different sets of gold nanoparticles, with final IC50 values of 87 µM and 94.7 µM, reaching a maximum cell viability decrease of 80% The results do not indicate a significant difference between the cytotoxic effects produced by the gold nanoparticles synthesized in this study and vincristine on normal lymphoblasts (CRL-1991).

Shock Wave Application Increases the Antineoplastic Effect of Molecular Iodine Supplement in Breast Cancer Xenografts.

We evaluated the effect of oral molecular iodine supplementation and shock wave application under three different conditions on human MDA-MB231 cancer cell xenografts. After tumor volume reached 1 cm3, mice were randomly assigned to groups and treated for 3 weeks. The results revealed that high-dose shock wave treatment (150 shock waves at a pressure of 21.7 MPa, SW150/21.7) generated tissue lesions without decreasing tumor growth, canceled the antineoplastic action of iodine and promoted pro-tumor conditions (increased hypoxia-induced factor [HIF] and vascular endothelial growth factor [VEGF]). In contrast, moderate (SW35/21.7) and low (SW35/9.9) doses of shock waves had significant antineoplastic effects and, in combination with iodine supplement, attenuated the aggressiveness of these cells by decreasing expression of the markers of stem cells (CD44 and Sox2) and invasion (HIF and VEGF). These results allow us to propose the combination of shock waves and iodine as a possible adjuvant in breast cancer therapy.

pMEX01, a 70kb Plasmid Isolated From Escherichia Coli That Confers Resistance to Multiple ß-Lactam Antibiotics

Abstract Multidrug-resistant microorganisms are of great concern to public health. Genetic mobile elements, such as plasmids, are among the most relevant mechanisms by which bacteria achieve this resistance. We obtained an Escherichia coli strain CM6, isolated from cattle presenting severe diarrheic symptoms in the State of Querétaro, Mexico. It was found to contain a 70 kb plasmid (pMEX01) with a high similarity to the pHK01-like plasmids that were previously identified and described in Hong Kong. Analysis of the pMEX01 sequence revealed the presence of a blaCTX-M-14 gene, which is responsible for conferring resistance to multiple β-lactam antibiotics. Several genes putatively involved in the conjugative transfer were also identified on the plasmid. The strain CM6 is of high epidemiological concern because it not only displays resistance to multiple β-lactam antibiotics but also to other kinds of antibiotics.

Shock wave-induced permeabilization of mammalian cells.

Controlled permeabilization of mammalian cell membranes is fundamental to develop gene and cell therapies based on macromolecular cargo delivery, a process that emerged against an increasing number of health afflictions, including genetic disorders, cancer and infections. Viral vectors have been successfully used for macromolecular delivery; however, they may have unpredictable side effects and have been limited to life-threatening cases. Thus, several chemical and physical methods have been explored to introduce drugs, vaccines, and nucleic acids into cells. One of the most appealing physical methods to deliver genes into cells is shock wave-induced poration. High-speed microjets of fluid, emitted due to the collapse of microbubbles after shock wave passage, represent the most significant mechanism that contributes to cell membrane poration by this technique. Herein, progress in shock wave-induced permeabilization of mammalian cells is presented. After covering the main concepts related to molecular strategies whose applications depend on safer drug delivery methods, the physics behind shock wave phenomena is described. Insights into the use of shock waves for cell membrane permeation are discussed, along with an overview of the two major biomedical applications thereof-i.e., genetic modification and anti-cancer shock wave-assisted chemotherapy. The aim of this review is to summarize 30 years of data showing underwater shock waves as a safe, noninvasive method for macromolecular delivery into mammalian cells, encouraging the development of further research, which is still required before the introduction of this promising tool into clinical practice.

Shock Wave-Induced Damage and Poration in Eukaryotic Cell Membranes.

Shock waves are known to permeabilize eukaryotic cell membranes, which may be a powerful tool for a variety of drug delivery applications. However, the mechanisms involved in shock wave-mediated membrane permeabilization are still poorly understood. In this study, the effects on both the permeability and the ultrastructural features of two human cell lineages were investigated after the application of underwater shock waves in vitro. Scanning Electron Microscopy of cells derived from a human embryo kidney (HEK)-293 and Michigan Cancer Foundation (MCF)-7 cells, an immortalized culture derived from human breast adenocarcinoma, showed a small amount of microvilli (as compared to control cells), the presence of hole-like structures, and a decrease in cell size after shock wave exposure. Interestingly, these effects were accompanied by the permeabilization of acid and macromolecular dyes and gene transfection. Trypan blue exclusion assays indicated that cell membranes were porated during shock wave treatment but resealed after a few seconds. Deformations of the cell membrane lasted for at least 5 min, allowing their observation in fixed cells. For each cell line, different shock wave parameters were needed to achieve cell membrane poration. This difference was correlated to successful gene transfection by shock waves. Our results demonstrate, for the first time, that shock waves induce transient micro- and submicrosized deformations at the cell membrane, leading to cell transfection and cell survival. They also indicate that ultrastructural analyses of cell surfaces may constitute a useful way to match the use of shock waves to different cells and settings.

In vivo evaluation of implant-host tissue interaction using morphology-controlled hydroxyapatite-based biomaterials.

In medicine, micro-electro-mechanical systems (MEMS) perform several specific functions. The design of bio-packages for MEMS to be implanted into the human body has been an increasing challenge in the last years. Mechanical, chemical and thermal resistance, as well as excellent bonding to silicon surfaces, are needed. Furthermore, ideal bio-packages should minimize post-operative complications and be well accepted by the host. To reach this goal, two different morphology-controlled hydroxyapatite-based porous biomaterials were synthesized, implanted in rats and evaluated mechanically and histologically. The novel biomaterials were prepared at room temperature using synthetic hydroxyapatite micro-particles, silica nanoparticles and water-based resin and compared with a standard hydroxyapatite biomaterial. The morphology (porosity) was controlled to obtain interconnected pores with appropriated pore size and pore volume fraction. All biomaterials were implanted in rats at the dorsal area near the third thoracic vertebra. The rats were killed 2, 7 and 21 days after surgery. Histological analysis revealed that the implants were well accepted by the host and minimal local inflammation was observed. The acute inflammatory response disappeared 21 days after surgery for both novel biomaterials. Additionally, organic matter (collagen) was produced in the interior of the porous biomaterial, indicating that an incipient vascularization process was in progress after 21 days of implantation. Both new biomaterials showed high abrasion resistance, high Young modulus, the appropriate porosity to allow possible vascularization, and good bonding to silicon surfaces.

Percutaneous renal access: the learning curve of a simplified approach.

BACKGROUND AND PURPOSE: Fluoroscopically guided techniques to access the kidney percutaneously with low exposure to radiation have been used successfully for many years in our training center. The purpose of this study was to analyze the learning process and to establish the number of procedures necessary for a nonexperienced urologist to achieve competence at performing percutaneous renal access. MATERIALS AND METHODS: Eighty-two percutaneous renal accesses in patients with renal stones or ureteropelvic junction obstruction were evaluated. The time needed to perform a correct puncture and the fluoroscopic screening time were recorded for each renal access. Descriptive analysis, analysis of variance, and a Markov chain were used to analyze the results. RESULTS: The rate of success increased from 82.5% to 97.6% after the first 40 punctures. Puncture time and fluoroscopy time decreased as the number of procedures increased. Incidence of complications was 30% for the first 20 cases, decreasing to 10% in the next 20 cases and 3.7% in the last 33 cases. CONCLUSIONS: The fluoroscopy-guided approach used in this study is an effective and reproducible technique. Our analysis revealed that at least 50 procedures are needed to acquire reliable competence in obtaining access to the kidney.

Interaction of shockwaves with infected kidney stones: is there a bactericidal effect?

BACKGROUND AND PURPOSE: Many calculi contain bacteria, which can remain active inside kidney stones and cause infection after lithotripsy. Reduction in renal infections after extracorporeal shockwave lithotripsy has been observed; however, results are controversial, and no information on the effect of shockwaves on bacteria inside kidney stones has been reported. The purpose of this research was to study whether bacteria inside kidney stones can be inactivated by shockwaves. MATERIALS AND METHODS: A series of infected artificial kidney stones were exposed in vitro to either 90 or 400 shockwaves using a research electrohydraulic or a commercial piezoelectric lithotripter. Two types of stones (soft and hard) were manufactured by mixing gypsum cement and Vel-mix-stone with water. Half of the stones were inoculated with Salmonella typhimurium. The suspension containing stone powder and bacteria was inoculated on agar plates and incubated. Bactericidal action was defined as the logarithmic viability reduction. RESULTS: About 95% of the bacteria were inactivated with 400 shockwaves using the electrohydraulic lithotripter; however, most of the damage was associated with the electromagnetic emission (ultraviolet radiation and visible light) generated at the spark gap. After 2730 shockwaves to stones placed inside a black polypropylene bag, about 29% and 14% of all bacteria were inactivated with the piezoelectric and the electrohydraulic lithotripter, respectively. In this case, the electromagnetic radiation was blocked by the black bag. CONCLUSIONS: Bacteria inactivation is possible by in vitro shockwave application; however, according to our results, no significant bactericidal effect is expected during extracorporeal shockwave lithotripsy.

Percutaneous renal access: a simplified approach.

PURPOSE: To present a simplified surgical technique to access the kidney percutaneously with low exposure to radiation. MATERIAL AND METHODS: This percutaneous approach to the kidney "creates" a plane of coincidence between the C-arm beam axis and the needle axis. Both axes always have the same angle running in opposite directions with the predetermined calix located in the medial vertical plane at 0 degrees. Twenty-one percutaneous access tracts were made into the lower calix and 7 into the middle and upper calices. The 3-dimensional position of the inserted needle was determined. RESULTS: All tracts were successfully accomplished. Statistical analysis of 28 procedures revealed that the technique is reproducible. The coefficient of variation of the angle determining the entrance position of the needle was low, which indicated that the procedure is reproducible and easy to teach. CONCLUSION: The technique is safe, easy to perform, reproducible, and requires less radiation than other methods.

Primer tratamiento de litotripsia extracorporal en un perro usando un generador de ondas de choque experimental hecho en México / First extracorporeal shock wave lithotripsy in a dog using an experimental device made in Mexico

La litotripsia extracorporal por ondas de choque ha sido usada con éxito para fragmentar cálculos renales y ureterales en humanos desde 1980. En este artículo se informa de un tratamiento de litotripsia estracorporal en un perro con un cálculo no inducido implantado en la vejiga, usando un generador de ondas de choque experimental hecho en el país. Después de dos tratamientos el perro eliminó todos los fragmentos y las arenillas del cálculo. Este artículo puede representar la base para el desarrollo de la litrotipsia extracorporal para animales usando equipos relativamente baratos y fáciles de construir

Primeras pruebas en vivo en roedores y perros en México con el generador de ondas de choque Mexilit I / First in vivo tests in rodents and dogs in Mexico using the MEXILIT shock wave generator

El presente artículo describe los resultados de las primeras pruebas in vivo en roedores y perros para determinar el daño causado a diferentes órganos y tejidos expuestos al generador de ondas de choque MEXILIT I.