scholarly journals A Review of In-Vivo and In-Vitro Real-Time Corrosion Monitoring Systems of Biodegradable Metal Implants

2020 ◽  
Vol 10 (9) ◽  
pp. 3141 ◽  
Author(s):  
Priscilla Yin Yee Chin ◽  
Quentin Cheok ◽  
Adam Glowacz ◽  
Wahyu Caesarendra

In current modern medicine, biodegradable metal implants are still considered a work-in-progress between the collaborations of both scientists and engineers. As of now, one of the obstacles to this development is monitoring the corrosion rate of the implant. When a biodegradable metal implant (made of Mg, Zn, etc.) is introduced into the harsh environment of the human body, corrosion naturally occurs, causing metal ions to be released which may result in undesired health effects. The released products of the corroding implant can be used to monitor the implant condition. This paper discusses the current real-time corrosion monitoring systems (i.e., electrochemical-, microsensor-, and microdialysis-based) in-vivo and in-vitro. It is acknowledged that the progress in this sector still requires extensive research in order to obtain a desirable monitoring system and it is hoped that this review paper contributes to the research.

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 282 ◽  
Author(s):  
Mokhamad Fakhrul Ulum ◽  
Wahyu Caesarendra ◽  
Reza Alavi ◽  
Hendra Hermawan

Absorbable metals have been introduced as materials to fabricate temporary medical implants. Iron, magnesium and zinc have been considered as major base elements of such metals. The metallurgical characterization and in-vitro corrosion assessment of these metals have been covered by the new ASTM standards F3160 and F3268. However, the in-vivo corrosion characterization and assessment of absorbable metal implants are not yet well established. The corrosion of metals in the in-vivo environment leads to metal ion release and corrosion product formation that may cause excessive toxicity. The aim of this work is to introduce the techniques to assess absorbable metal implants and their in-vivo corrosion behavior. This contains the existing approaches, e.g., implant retrieval and histological analysis, ultrasonography and radiography, and the new techniques for real-time in-vivo corrosion monitoring.


2019 ◽  
Vol 18 (26) ◽  
pp. 2209-2229 ◽  
Author(s):  
Hai Pham-The ◽  
Miguel Á. Cabrera-Pérez ◽  
Nguyen-Hai Nam ◽  
Juan A. Castillo-Garit ◽  
Bakhtiyor Rasulev ◽  
...  

One of the main goals of in silico Caco-2 cell permeability models is to identify those drug substances with high intestinal absorption in human (HIA). For more than a decade, several in silico Caco-2 models have been made, applying a wide range of modeling techniques; nevertheless, their capacity for intestinal absorption extrapolation is still doubtful. There are three main problems related to the modest capacity of obtained models, including the existence of inter- and/or intra-laboratory variability of recollected data, the influence of the metabolism mechanism, and the inconsistent in vitro-in vivo correlation (IVIVC) of Caco-2 cell permeability. This review paper intends to sum up the recent advances and limitations of current modeling approaches, and revealed some possible solutions to improve the applicability of in silico Caco-2 permeability models for absorption property profiling, taking into account the above-mentioned issues.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Di Girolamo ◽  
M Appignani ◽  
N Furia ◽  
M Marini ◽  
P De Filippo ◽  
...  

Abstract Background Direct exposure of implantable cardioverter-defibrillators (ICDs) during radiotherapy is still considered potentially harmful, or even unsafe, by manufacturers and current recommendations. The effects of photon beams on ICDs are unpredictable, depending on multiple factors, and malfunctions may present during exposure. Purpose To evaluate transient ICD malfunctions by direct exposure to doses up to 10 Gy during low-energy RT, forty-three contemporary wireless-enabled ICDs, with at least 4 months to elective replacement indicator (ERI) were evaluated in a real-time in-vitro session in three different centres. Methods All ICDs had baseline interrogation. Single chamber devices were programmed to the VVI/40 mode and dual or triple chamber devices were programmed to the DDD/40 mode. Rate response function and antitachycardia therapies were disabled, with the ventricular tachycardia (VT)/ventricular fibrillation (VF) detection windows still active. A centring computed tomography was performed to build the corresponding treatment plan and the ICDs were blinded randomized to receive either 2-, 5- or 10-Gy exposure by a low photon-energy linear accelerator (6MV) in a homemade water phantom (600 MU/min). The effective dose received by the ICDs was randomly assessed by an in-vivo dosimetry. During radiotherapy, the ICDs were observed in a real-time session using manufacturer specific programmer, and device function (pacing, sensing, programmed parameters, arrhythmia detections) was recorder by the video camera in the bunker throughout the entire photon exposure. All ICDs had an interrogation session immediately after exposure. Results During radiotherapy course, almost all ICDs (93%) recorded major or minor transient electromagnetic interferences. On detail, sixteen ICDs (37.2%) reported atrial and/or ventricular oversensing, with base-rate-pacing inhibition and VT/VF detection. Twenty-four ICDs (55.8%) recorded non clinically relevant noise, and no detections were observed. Only three ICDs (7%) reported neither transient malfunction nor minor noise, withstanding direct radiation exposure. At immediate post-exposure interrogation, the ICDs that recorded major real-time malfunctions had VT/VF detections stored in the device memory. In none of the ICDs spontaneous changes in parameter settings were reported. Malfunctions occurred regardless of either 2-, 5- or 10-Gy photon beam exposure. Conclusions Transient electromagnetic interferences were observed in most of the contemporary ICDs during radiotherapy course, regardless of photon dose. To avoid potentially life-threatening ICD malfunctions such as pacing inhibition or inappropriate shock delivery, magnet application on the pocket site or ICD reprogramming to the asynchronous mode are still suggested in ICD patients ongoing even low energy radiotherapy exposure. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 900 ◽  
pp. 115674
Author(s):  
Muthaiah Annalakshmi ◽  
Sakthivel Kumaravel ◽  
T.S.T. Balamurugan ◽  
Shen-Ming Chen ◽  
Ju-Liang He

2015 ◽  
Vol 51 (32) ◽  
pp. 6948-6951 ◽  
Author(s):  
Yanfeng Zhang ◽  
Qian Yin ◽  
Jonathan Yen ◽  
Joanne Li ◽  
Hanze Ying ◽  
...  

Anin vitroandin vivodrug-reporting system is developed for real-time monitoring of drug release via the analysis of the concurrently released near-infrared fluorescence dye.


mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Christina D. Orrú ◽  
Jason M. Wilham ◽  
Lynne D. Raymond ◽  
Franziska Kuhn ◽  
Björn Schroeder ◽  
...  

ABSTRACT A key challenge in managing transmissible spongiform encephalopathies (TSEs) or prion diseases in medicine, agriculture, and wildlife biology is the development of practical tests for prions that are at or below infectious levels. Of particular interest are tests capable of detecting prions in blood components such as plasma, but blood typically has extremely low prion concentrations and contains inhibitors of the most sensitive prion tests. One of the latter tests is quaking-induced conversion (QuIC), which can be as sensitive as in vivo bioassays, but much more rapid, higher throughput, and less expensive. Now we have integrated antibody 15B3-based immunoprecipitation with QuIC reactions to increase sensitivity and isolate prions from inhibitors such as those in plasma samples. Coupling of immunoprecipitation and an improved real-time QuIC reaction dramatically enhanced detection of variant Creutzfeldt-Jakob disease (vCJD) brain tissue diluted into human plasma. Dilutions of 1014-fold, containing ~2 attogram (ag) per ml of proteinase K-resistant prion protein, were readily detected, indicating ~10,000-fold greater sensitivity for vCJD brain than has previously been reported. We also discriminated between plasma and serum samples from scrapie-infected and uninfected hamsters, even in early preclinical stages. This combined assay, which we call “enhanced QuIC” (eQuIC), markedly improves prospects for routine detection of low levels of prions in tissues, fluids, or environmental samples. IMPORTANCE Transmissible spongiform encephalopathies (TSEs) are largely untreatable and are difficult to diagnose definitively prior to irreversible clinical decline or death. The transmissibility of TSEs within and between species highlights the need for practical tests for even the smallest amounts of infectivity. A few sufficiently sensitive in vitro methods have been reported, but most have major limitations that would preclude their use in routine diagnostic or screening applications. Our new assay improves the outlook for such critical applications. We focused initially on blood plasma because a practical blood test for prions would be especially valuable for TSE diagnostics and risk reduction. Variant Creutzfeldt-Jakob disease (vCJD) in particular has been transmitted between humans via blood transfusions. Enhanced real-time quaking-induced conversion (eRTQ) provides by far the most sensitive detection of vCJD to date. The 15B3 antibody binds prions of multiple species, suggesting that our assay may be useful for clinical and fundamental studies of a variety of TSEs of humans and animals.


2020 ◽  
Vol 9 ◽  
pp. 1743
Author(s):  
Solmaz Rahmani Barouji ◽  
Amir Saber ◽  
Mohammadali Torbati ◽  
Seyyed Mohammad Bagher Fazljou ◽  
Ahmad Yari Khosroushahi

raditional medicine (TM) that developed over the years within various societies consists of medical experimental knowledge and practices, which apply natural methods and compounds for general wellness and healing. Moomiaii as a pale-brown to blackish-brown natural exudate is one of the natural compounds in traditional medicine that has been used over 3000 years in many countries of the world especially in India, China, Russia, Iran, Mongolia, Kazakhstan and Kirgizstan. We reviewed all English-language studies about Moomiaii that we accessed them. In traditional medicine, many beneficial activities have been attributed to Moomiaii and to its main constituents, Humic acid and Fulvic acid, which are widely used to prevent and treatment of different diseases. Some modern scientific investigations showed that Moomiaii as a safe dietary supplement can be beneficial in various health complications. Even though the beneficial effects of Moomiaii have been confirmed in traditional and modern medicine, it seems that additional in-vitro/in-vivo studies and comprehensive clinical trials are necessary to explain the whole mechanisms of action and to determine the effective doses in various diseases. We discuss and clarify the claimed health beneficial effects of Moomiaii in some wide-spread diseases regarding its anti-ulcerogenic, immunomodulatory, antidiabetic, antioxidative and anticancer properties. [GMJ.2020;9:e1743]


2021 ◽  
Vol 11 ◽  
Author(s):  
Dong Chen ◽  
Yaqin Wang ◽  
Feiya Yang ◽  
Adili Keranmu ◽  
Qingxin Zhao ◽  
...  

An increasing number of studies have shown that circRNAs are closely related to the carcinogenesis and development of prostate cancer (PCa). However, little is known about the effect of the biological functions of circRNAs on the enzalutamide resistance of PCa. Through bioinformatic analysis and experiments, we investigated the expression pattern of circRNAs in enzalutamide-resistant PCa cells. Quantitative real-time PCR was used to detect the expression of circRAB3IP, and plasmids that knock down or overexpress circRAB3IP were used to evaluate its effect on the enzalutamide sensitivity of PCa cells. Mechanistically, we explored the potential regulatory effects of eIF4A3 and LEF1 on the biogenesis of circRAB3IP. Our in vivo and in vitro data indicated that increased expression of circRAB3IP was found in enzalutamide-resistant PCa, and knockdown of circRAB3IP significantly enhanced enzalutamide sensitivity in PCa cells. However, upregulation of circRAB3IP resulted in the opposite effects. Further mechanistic research demonstrated that circRAB3IP could regulate the expression of serum and glucocorticoid-regulated kinase 1 (SGK1) by serving as a sponge that directly targets miR-133a-3p/miR-133b. Then, we showed that circRAB3IP partially exerted its biological functions via SGK1 signaling. Furthermore, we discovered that eIF4A3 and LEF1 might increase circRAB3IP expression in PCa.


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