scholarly journals Effect of sterilization on 3-point dynamic response to in vitro bending of an Mg implant.

2021 ◽  
Author(s):  
Luis Humberto Campos Becerra ◽  
Marco Antonio Loudovic Hernández Rodríguez ◽  
Raúl Lesso Arroyo ◽  
Hugo Esquivel S ◽  
Alejandro Torres Castro
Keyword(s):  
Fatigue Resistance ◽  
Medical Devices ◽  
Initial Period ◽  
The Body ◽  
Sterilization Method ◽  
Toxicological Effects ◽  
Intramedullary Implant ◽  
We43 Alloy

Abstract Background: The aim of the study is to characterize a biomedical magnesium alloy and highlighting the loss of mechanical integrity due to the sterilization method. Ideally, when using these alloys is to delay the onset of degradation so that the implant can support body loads and avoid toxicological effects due to the release of metal ions into the body. Methods: Standardized procedures according to ASTM F-1264 and ISO-10993-5 were used, respecting detailed methodological controls to ensure accuracy and reproducibility of the results, this testing methodology is carried out in accordance with the monographs of the Pharmacopoeia for the approval of medical devices and obtaining a health registration. An intramedullary implant (IIM) manufactured in magnesium (Mg) WE43 can support loads of the body in the initial period of bone consolidation without compromising the integrity of the fractured area. A system with these characteristics would improve morbidity and health costs by avoiding secondary surgical interventions. Results: As a property, the fatigue resistance of Mg in aggressive environments such as the body environment undergoes progressive degradation, however, the autoclave sterilization method drastically affects fatigue resistance, as demonstrated in tests carried out under in vitro conditions. Coupled with this phenomenon, the relatively poor biocompatibility of Mg WE43 alloys has limited applications where they can be used due to low acceptance rates from agencies such as the FDA. However, Mg alloy with elements such as yttrium and rare earth elements (REEs) have been shown to delay biodegradation depending on the method of sterilization and the physiological solution used. With different sterilization techniques, it may be possible to keep toxicological effects to a minimum while still ensuring a balance between the integrity of fractured bone and implant degradation time. Therefore, the evaluation of fatigue resistance of WE43 specimens sterilized and tested in immersion conditions (enriched Hank's solution) and according to ASTM F-1264, along with the morphological, crystallinity, and biocompatibility characterization of the WE43 alloy allows for a comprehensive evaluation of the mechanical and biological properties of WE43. Conclusions: These results will support decision-making to generate a change in the current perspective of biomaterials utilized in medical devices (MDs), to be considered by manufacturers and health regulatory agencies. An implant manufactured in WE43 alloy can be used as an intramedullary implant, considering keeping elements such as yttrium-REEs below as specified in its designation and with the help of a coating that allows increasing the life of the implant in vivo.Trial registration: N/A

scholarly journals Effect of Sterilization on 3-point Dynamic Response to in Vitro Bending of an Mg Implant

2020 ◽  
Author(s):  
Luis Humberto Campos Becerra ◽  
Marco Antonio Loudovic Hernández Rodríguez ◽  
Raúl Lesso Arroyo ◽  
Hugo Esquivel S ◽  
Alejandro Torres Castro
Keyword(s):  
Fatigue Resistance ◽  
Medical Devices ◽  
Initial Period ◽  
The Body ◽  
Sterilization Method ◽  
Toxicological Effects ◽  
Intramedullary Implant ◽  
We43 Alloy

Abstract Background: The aim of the study is to characterize a biomedical magnesium alloy and highlighting the loss of mechanical integrity due to the sterilization method. Ideally, when using these alloys is to delay the onset of degradation so that the implant can support body loads and avoid toxicological effects due to the release of metal ions into the body. Methods: The experimentation was carried out according to the standards of ASTM-F-1264 and ISO-10993-5 for mechanical and biological tests respectively, this testing methodology is carried out in accordance with the monographs of the Pharmacopoeia for the approval of medical devices and obtaining a health registration. An intramedullary implant (IIM) manufactured in magnesium (Mg) WE43 can support loads of the body in the initial period of bone consolidation without compromising the integrity of the fractured area. A system with these characteristics would improve morbidity and health costs by avoiding secondary surgical interventions. As a property, the fatigue resistance of Mg in aggressive environments such as the body environment undergoes progressive degradation, however, the autoclave sterilization method drastically affects fatigue resistance, as demonstrated in tests carried out under in vitro conditions. Coupled with this phenomenon, the relatively poor biocompatibility of Mg WE43 alloys has limited applications where they can be used due to low acceptance rates from agencies such as the FDA. However, Mg alloy with elements such as yttrium and rare earth elements (REEs) have been shown to delay biodegradation depending on the method of sterilization and the physiological solution used.Results: With different sterilization techniques, it may be possible to keep toxicological effects to a minimum while still ensuring a balance between the integrity of fractured bone and implant degradation time. Therefore, the evaluation of fatigue resistance of WE43 specimens sterilized and tested in immersion conditions (enriched Hank's solution) and according to ASTM F-1264, along with the morphological, crystallinity, and biocompatibility characterization of the WE43 alloy allows for a comprehensive evaluation of the mechanical and biological properties of WE43. Conclusions: These results will support decision-making to generate a change in the current perspective of biomaterials utilized in medical devices (MDs), to be considered by manufacturers and health regulatory agencies. An implant manufactured in WE43 alloy can be used as an intramedullary implant, considering keeping elements such as yttrium-REEs below as specified in its designation and with the help of a coating that allows increasing the life of the implant in vivo.

scholarly journals Effect of sterilization on 3-point dynamic response to in vitro bending of an Mg implant

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Luis Humberto Campos Becerra ◽  
Marco Antonio Loudovic Hernández Rodríguez ◽  
Raúl Lesso Arroyo ◽  
Hugo Esquivel Solís ◽  
Alejandro Torres Castro
Keyword(s):  
Fatigue Resistance ◽  
Medical Devices ◽  
Initial Period ◽  
The Body ◽  
Sterilization Method ◽  
Toxicological Effects ◽  
Intramedullary Implant ◽  
We43 Alloy

Abstract Background The aim of the study is to characterize a biomedical magnesium alloy and highlighting the loss of mechanical integrity due to the sterilization method. Ideally, when using these alloys is to delay the onset of degradation so that the implant can support body loads and avoid toxicological effects due to the release of metal ions into the body. Methods Standardized procedures according to ASTM F-1264 and ISO-10993-5 were used, respecting detailed methodological controls to ensure accuracy and reproducibility of the results, this testing methodology is carried out in accordance with the monographs of the Pharmacopoeia for the approval of medical devices and obtaining a health registration. An intramedullary implant (IIM) manufactured in magnesium (Mg) WE43 can support loads of the body in the initial period of bone consolidation without compromising the integrity of the fractured area. A system with these characteristics would improve morbidity and health costs by avoiding secondary surgical interventions. Results As a property, the fatigue resistance of Mg in aggressive environments such as the body environment undergoes progressive degradation, however, the autoclave sterilization method drastically affects fatigue resistance, as demonstrated in tests carried out under in vitro conditions. Coupled with this phenomenon, the relatively poor biocompatibility of Mg WE43 alloys has limited applications where they can be used due to low acceptance rates from agencies such as the FDA. However, Mg alloy with elements such as yttrium and rare earth elements (REEs) have been shown to delay biodegradation depending on the method of sterilization and the physiological solution used. With different sterilization techniques, it may be possible to keep toxicological effects to a minimum while still ensuring a balance between the integrity of fractured bone and implant degradation time. Therefore, the evaluation of fatigue resistance of WE43 specimens sterilized and tested in immersion conditions (enriched Hank’s solution) and according to ASTM F-1264, along with the morphological, crystallinity, and biocompatibility characterization of the WE43 alloy allows for a comprehensive evaluation of the mechanical and biological properties of WE43. Conclusions These results will support decision-making to generate a change in the current perspective of biomaterials utilized in medical devices (MDs), to be considered by manufacturers and health regulatory agencies. An implant manufactured in WE43 alloy can be used as an intramedullary implant, considering keeping elements such as yttrium-REEs below as specified in its designation and with the help of a coating that allows increasing the life of the implant in vivo.

scholarly journals Ion Leaching from Implantable Medical Devices

2010 ◽  
Vol 638-642 ◽  
pp. 754-759
Author(s):  
Lawrence E. Eiselstein ◽  
Robert D. Caligiuri
Keyword(s):  
Medical Devices ◽  
Stainless Steels ◽  
The Body ◽  
Cobalt Chromium ◽  
Implantable Medical Devices ◽  
Device Development ◽  
Soluble Ions ◽  
Chromium Alloys

Implantable medical devices must be able to withstand the corrosive environment of the human body for 10 or more years without adverse consequences. Most reported research and development has been on developing materials and devices that are biocompatible and resistant to corrosion-fatigue, pitting, and crevice corrosion. However, little has been directly reported regarding implantable materials with respect to the rate at which they generate soluble ions in-vivo. Most of the biocompatibility studies have been done by examining animal implants and cell cultures rather than examining the rate at which these materials leach ions into the body. This paper will discuss what is currently known about the rate at which common implant materials (such as stainless steels, cobalt-chromium alloys, and nitinol) elute ions under in vitro conditions, what the limitations are of such data, and how this data can be used in medical device development.

scholarly journals Toxic Effects of Di-2-ethylhexyl Phthalate: An Overview

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Sai Sandeep Singh Rowdhwal ◽  
Jiaxiang Chen
Keyword(s):  
Animal Models ◽  
Human Health ◽  
Waste Disposal ◽  
Medical Devices ◽  
Daily Basis ◽  
The Body ◽  
Repeated Use ◽  
Ethylhexyl Phthalate

Di-2-ethylhexyl phthalate (DEHP) is extensively used as a plasticizer in many products, especially medical devices, furniture materials, cosmetics, and personal care products. DEHP is noncovalently bound to plastics, and therefore, it will leach out of these products after repeated use, heating, and/or cleaning of the products. Due to the overuse of DEHP in many products, it enters and pollutes the environment through release from industrial settings and plastic waste disposal sites. DEHP can enter the body through inhalation, ingestion, and dermal contact on a daily basis, which has raised some concerns about its safety and its potential effects on human health. The main aim of this review is to give an overview of the endocrine, testicular, ovarian, neural, hepatotoxic, and cardiotoxic effects of DEHP on animal models and humansin vitroandin vivo.

scholarly journals Health concerns of various nanoparticles: A review of their in vitro and in vivo toxicity

2018 ◽  
Author(s):  
Marziyeh Ajdari ◽  
Mohammad Moosavi ◽  
Marweh Rahmati ◽  
Mojtaba Falahati ◽  
Mohammad Mahboubi ◽  
...  
Keyword(s):  
Targeted Drug Delivery ◽  
The Body ◽  
Accurate Information ◽  
Central Question ◽  
Key Factors ◽  
Toxicological Effects ◽  
The Subject ◽  
Comparison Of The Results

Nanoparticles (NPs) are widely used in diverse disciplines, including biology, medicine science. The central question that need to be answered is whether NPs have toxic effects on biological cells and molecules or are they safe. The safety of NPs including targeted drug delivery is critical and so is their toxicity in the environment. In recent years, in vitro and in vivo research on animals has generated abundant information about the toxicity of NPs. However, due to varying laboratory conditions, the comparison of the results from ensuing studies is somewhat unreliable. It should be noted that, depending on the type of production, NPs can enter the body through inhalation, skin and via digestive routes. Due to the diversity of NPs and their properties, there is paucity of accurate information on their toxicological effects; particle size, shape, surface area and the chemical levels are considered as key factors in creating health and toxicological effects. Consequently, there is a need for reliable information about their effects on various organs so as to deal with NPs effectively and their impact on health and the environment. This review covers the existing knowledge base on the subject that hopefully prepares us better to address these challenges.

Release of Growth Factor from Platelet-Rich Fibrin and its Stability in Sinus Lifting in Minipigs

2012 ◽  
Vol 506 ◽  
pp. 367-370
Author(s):  
N. Pattaraporncharoen ◽  
P. Pripatnanont ◽  
S. Suttapreyasri ◽  
N. Leepong
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Ex Vivo ◽  
Initial Period ◽  
In Vitro Study ◽  
The Body ◽  
Platelet Rich Fibrin ◽  
Platelet Concentration

Platelet-rich fibrin (PRF) is platelet concentration that contains growth factors and acts as a biodegradable scaffold. The aims of this study were to determinethe quantity ofentrappedgrowth factors (Platelet derived growth factor BB, PDGF-BB) in the PRF and radiographically assess the stability of the fibrin in maintaining the lifted sinus space in minipigs. From the in vitro study, PRF was found slowly releasing thegrowth factor, PDGF-BB, during the ex-vivo period of 60 minutes, and the amount (1,963.93±380.17 pg/ml) was comparable to the total amount from immediate extraction either by physical (2,492.2±199.78 pg/ml) or chemical lysis (2,227.32±566.59 pg/ml).In vivo study, PRF wasable to be retained in the sinus of minipigs with minimal collapse during the first 2 weeks after application. PRF has been proven to be a source for growth factors and is able to be retained in the body during the initial period of wound healing.

Nanotechnology-based Drug Delivery, Metabolism and Toxicity

2020 ◽  
Vol 20 (14) ◽  
pp. 1167-1190 ◽  
Author(s):  
Pooja Malaviya ◽  
Dhaval Shukal ◽  
Abhay R. Vasavada
Keyword(s):  
Drug Delivery ◽  
Medical Devices ◽  
Targeted Delivery ◽  
Literature Search ◽  
Experimental Models ◽  
Clinical Safety ◽  
Toxicological Effects ◽  
Primary Focus

Background: Nanoparticles (NPs) are being used extensively owing to their increased surface area, targeted delivery and enhanced retention. NPs have the potential to be used in many disease conditions. Despite widespread use, their toxicity and clinical safety still remain a major concern. Objective: The purpose of this study was to explore the metabolism and toxicological effects of nanotherapeutics. Methods: Comprehensive, time-bound literature search was done covering the period from 2010 till date. The primary focus was on the metabolism of NP including their adsorption, degradation, clearance, and bio-persistence. This review also focuses on updated investigations on NPs with respect to their toxic effects on various in vitro and in vivo experimental models. Results: Nanotechnology is a thriving field of biomedical research and an efficient drug delivery system. Further their applications are under investigation for diagnosis of disease and as medical devices. Conclusion: The toxicity of NPs is a major concern in the application of NPs as therapeutics. Studies addressing metabolism, side-effects and safety of NPs are desirable to gain maximum benefits of nanotherapeutics.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Репрограммированые in vitro на М3 фенотип макрофаги останавливают рост солидной карциномы in vivo

2018 ◽  
pp. 41-46
Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  
Keyword(s):  
Solid Tumor ◽  
Antitumor Effect ◽  
Tumor Development ◽  
Significant Inhibition ◽  
The Body ◽  
Ehrlich Carcinoma ◽  
Solid Carcinoma ◽  
Ec Cells

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.

Nanocurcumin: A Double-Edged Sword for Microcancers

2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam
Keyword(s):  
Intracellular Signaling ◽  
Dosage Forms ◽  
The Body ◽  
In Vivo Studies ◽  
Mrna Levels ◽  
Anticancer Activities ◽  
Road Map ◽  
Anticancer Effects

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.

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