Materials For Medical Devices Research Articles

Bacterial Biofilm Growth on 3D-Printed Materials.

Recent advances in 3D printing have led to a rise in the use of 3D printed materials in prosthetics and external medical devices. These devices, while inexpensive, have not been adequately studied for their ability to resist biofouling and biofilm buildup. Bacterial biofilms are a major cause of biofouling in the medical field and, therefore, hospital-acquired, and medical device infections. These surface-attached bacteria are highly recalcitrant to conventional antimicrobial agents and result in chronic infections. During the COVID-19 pandemic, the U.S. Food and Drug Administration and medical officials have considered 3D printed medical devices as alternatives to conventional devices, due to manufacturing shortages. This abundant use of 3D printed devices in the medical fields warrants studies to assess the ability of different microorganisms to attach and colonize to such surfaces. In this study, we describe methods to determine bacterial biofouling and biofilm formation on 3D printed materials. We explored the biofilm-forming ability of multiple opportunistic pathogens commonly found on the human body including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus to colonize eight commonly used polylactic acid (PLA) polymers. Biofilm quantification, surface topography, digital optical microscopy, and 3D projections were employed to better understand the bacterial attachment to 3D printed surfaces. We found that biofilm formation depends on surface structure, hydrophobicity, and that there was a wide range of antimicrobial properties among the tested polymers. We compared our tested materials with commercially available antimicrobial PLA polymers.

Antithrombogenic poly(2-methoxyethyl acrylate) elastomer via triblock copolymerization with poly(methyl methacrylate)

For the development of blood-contacting biomedical devices, preventing platelet adhesion and avoiding subsequent thrombosis through antithrombogenic surface are vitally important. Poly (2-methoxyethyl acrylate) (PMEA) is a synthetic viscous polymer with an excellent antithrombogenic property, which has already been used as an antithrombogenic coating for biomedical purposes. The PMEA coating, however, can be easily broken due to its liquid-like feature, since the glass transition temperature (Tg) of PMEA is at −25οC. Solidifying PMEA has, therefore, been desperately desired for the improvement of the stability of PMEA coating. Also, once solidified, PMEA could be utilized not only for coating but also for structural materials for medical devices, expanding the application range of PMEA. In this study, PMEA was first solidified by triblock copolymerization with poly (methyl methacrylate) (PMMA) to obtain thermoplastic elastomers with excellent antithrombogenicity. We synthesized PMMA-PMEA-PMMA triblock copolymers with different volume fractions of PMMA (fMMA) by atom transfer radical polymerization (ATRP). The synthesis and the chemical structures of the new triblock copolymers were characterized and confirmed by proton nuclear magnetic resonance (1H NMR) analyses and gel permeation chromatography (GPC). The synthesized elastomeric triblocks were then compression-molded at 180οC to obtain solid transparent films. The tensile property was measured and the drastic change from the soft-elastomer phase to the hard-plastic phase was clearly observed by varying fMMA. It was found that the new triblocks possessed significantly higher tensile strengths than the other solidified PMEA by the previous studies. The platelet adhesion test revealed that the number of adherent platelets on the triblocks with fMMA of 0.12 and 0.40 was almost the same as that on pure PMEA, indicating that the synthesized triblocks possessed excellent antithrombogenicity similar to liquid PMEA. Further investigation on hydrated water and microphase-separated structures eventually revealed that the new triblock copolymers with a sufficient amount of intermediate water or with microphase separation on the surface resulted in excellent antithrombogenicity.

Medical Device Industry Approaches for Addressing Sources of Failing Cytotoxicity Scores

To ensure patient safety, medical device manufacturers are required by the Food and Drug Administration and other regulatory bodies to perform biocompatibility evaluations on their devices per standards, such as the AAMI-approved ISO 10993-1:2018 (ANSI/AAMI/ISO 10993-1:2018).However, some of these biological tests (e.g., systemic toxicity studies) have long lead times and are costly, which may hinder the release of new medical devices. In recent years, an alternative method using a risk-based approach for evaluating the toxicity (or biocompatibility) profile of chemicals and materials used in medical devices has become more mainstream. This approach is used as a complement to or substitute for traditional testing methods (e.g., systemic toxicity endpoints). Regardless of the approach, the one test still used routinely in initial screening is the cytotoxicity test, which is based on an in vitro cell culture system to evaluate potential biocompatibility effects of the final finished form of a medical device. However, it is known that this sensitive test is not always compatible with specific materials and can lead to failing cytotoxicity scores and an incorrect assumption of potential biological or toxicological adverse effects. This article discusses the common culprits of in vitro cytotoxicity failures, as well as describes the regulatory-approved methodology for cytotoxicity testing and the approach of using toxicological risk assessment to address clinical relevance of cytotoxicity failures for medical devices. Further, discrepancies among test results from in vitro tests, use of published half-maximal inhibitory concentration data, and the derivation of their relationship to tolerable exposure limits, reference doses, or no observed adverse effect levels are highlighted to demonstrate that although cytotoxicity tests in general are regarded as a useful sensitive screening assays, specific medical device materials are not compatible with these cellular/in vitro systems. For these cases, the results should be analyzed using more clinically relevant approaches (e.g., through chemical analysis or written risk assessment).

Light for a Potentially Cloudy Situation: Approach to Validating Cloud Computing Tools

Abstract To ensure patient safety, medical device manufacturers are required by the Food and Drug Administration and other regulatory bodies to perform biocompatibility evaluations on their devices per standards, such as the AAMI-approved ISO 10993-1:2018 (ANSI/AAMI/ISO 10993-1:2018).However, some of these biological tests (e.g., systemic toxicity studies) have long lead times and are costly, which may hinder the release of new medical devices. In recent years, an alternative method using a risk-based approach for evaluating the toxicity (or biocompatibility) profile of chemicals and materials used in medical devices has become more mainstream. This approach is used as a complement to or substitute for traditional testing methods (e.g., systemic toxicity endpoints). Regardless of the approach, the one test still used routinely in initial screening is the cytotoxicity test, which is based on an in vitro cell culture system to evaluate potential biocompatibility effects of the final finished form of a medical device. However, it is known that this sensitive test is not always compatible with specific materials and can lead to failing cytotoxicity scores and an incorrect assumption of potential biological or toxicological adverse effects. This article discusses the common culprits of in vitro cytotoxicity failures, as well as describes the regulatory-approved methodology for cytotoxicity testing and the approach of using toxicological risk assessment to address clinical relevance of cytotoxicity failures for medical devices. Further, discrepancies among test results from in vitro tests, use of published half-maximal inhibitory concentration data, and the derivation of their relationship to tolerable exposure limits, reference doses, or no observed adverse effect levels are highlighted to demonstrate that although cytotoxicity tests in general are regarded as a useful sensitive screening assays, specific medical device materials are not compatible with these cellular/in vitro systems. For these cases, the results should be analyzed using more clinically relevant approaches (e.g., through chemical analysis or written risk assessment).

Medical Device Industry Approaches for Addressing Sources of Failing Cytotoxicity Scores.

To ensure patient safety, medical device manufacturers are required by the Food and Drug Administration and other regulatory bodies to perform biocompatibility evaluations on their devices per standards, such as the AAMI-approved ISO 10993-1:2018 (ANSI/AAMI/ISO 10993-1:2018).However, some of these biological tests (e.g., systemic toxicity studies) have long lead times and are costly, which may hinder the release of new medical devices. In recent years, an alternative method using a risk-based approach for evaluating the toxicity (or biocompatibility) profile of chemicals and materials used in medical devices has become more mainstream. This approach is used as a complement to or substitute for traditional testing methods (e.g., systemic toxicity endpoints). Regardless of the approach, the one test still used routinely in initial screening is the cytotoxicity test, which is based on an in vitro cell culture system to evaluate potential biocompatibility effects of the final finished form of a medical device. However, it is known that this sensitive test is not always compatible with specific materials and can lead to failing cytotoxicity scores and an incorrect assumption of potential biological or toxicological adverse effects. This article discusses the common culprits of in vitro cytotoxicity failures, as well as describes the regulatory-approved methodology for cytotoxicity testing and the approach of using toxicological risk assessment to address clinical relevance of cytotoxicity failures for medical devices. Further, discrepancies among test results from in vitro tests, use of published half-maximal inhibitory concentration data, and the derivation of their relationship to tolerable exposure limits, reference doses, or no observed adverse effect levels are highlighted to demonstrate that although cytotoxicity tests in general are regarded as a useful sensitive screening assays, specific medical device materials are not compatible with these cellular/in vitro systems. For these cases, the results should be analyzed using more clinically relevant approaches (e.g., through chemical analysis or written risk assessment).

Influence of Aging, Sterilization, and Composition on the Degradation of Polyurethane Foams

Shape memory polymers (SMPs) are highly attractive materials for medical devices. Specifically, SMP foams are currently being used as embolic devices in peripheral and cerebral vascular applications. To ensure the proper function and safety of these materials in their intended applications, it is important to understand how processing treatments, such as aging, sterilization, and foam composition can influence their degradation. Here, SMP foams were treated with industry relevant processing parameters, and the influence on degradation was observed via gravimetric, chemical, and morphological studies. Accelerated thermal aging was shown to have an influence on material degradation rate in real time oxidative studies. Sterilization was performed via Electron beam (E-beam) irradiation at the high and low dosages commonly used in industry and had no significant influence on foam degradation profiles. These findings help inform appropriate treatment of SMP foam embolic devices to ensure their safety and efficacy.

Hydroxyapatite Coating on Stainless Steel 316L using Flame Spray Technique

This study was a preliminary study on flame spray coating with hydroxyapatite (HAp). Coating is one of the technique to improve metal resistance to corrosion. In this study, flame spray coating using HAp was performed on stainless steel 316 L as a material for medical devices. This synthetic compound contains elements which are biocompatible and bioactive in human body where they can stick to body tissues or muscles.HAp has been extensively used as a bone substitute because of its crystal structure, biocompatibility and osteoconductive nature. In this study, 316L SS was coated by HAp using flame spray method with varied oxygen flowrate and air pressure. The result of this study showed that the air pressure of 1 bar and oxygen flowrate of 25 l/min had the thickest coating which was 123.5μm and the lowest corrosion rate which was 0.0261 mm/year. The air pressureof 3 bar and oxygen flowrate of 35 l/min produced the lowest thickness which was 32.5μm and the highest corrosion rate which was 0.0761 mm/year. The use of high air pressure and oxygen flowrate decreased the coating thickness and the corrosion rate. The result revealed that flame spray method was effective to be used to coat HAp on 316L SS.

Examples of Malfunction Occurred by Interactions between Pharmaceutical Products and Medical Devices That Pharmacists Should Be Aware of

There have been a number of reports of medical device materials becoming denatured or damaged by interactions with pharmaceutical products. For example, the polycarbonate (PC) resin that is widely used in medical devices has the shortcoming of weak chemical resistance, and in more than one case, three-way stopcocks made of PC resin have been damaged when drugs like propofol are used. There have also been reports where concomitant use of pharmaceutical products prevented medical devices from exerting their effect properly. For example, owing to the heart-slowing action of amiodarone hydrochloride, a dose increase in a patient with an implantable cardioverter-defibrillator caused the device to fail to detect a sustained tachycardia attack, as a consequence of which defibrillation therapy was not administered. These are but a few of the numerous and varied interactions between pharmaceutical products and medical devices. We introduce the drug-medical device interactions that have been reported to Pharmaceuticals and Medical Devices Agency (PMDA) thus far.

Progress on Diamane and Diamanoid Thin Film Pressureless Synthesis

Nanometer-thick and crystalline sp3-bonded carbon sheets are promising new wide band-gap semiconducting materials for electronics, photonics, and medical devices. Diamane was prepared from the exposure of bi-layer graphene to hydrogen radicals produced by the hot-filament process at low pressure and temperature. A sharp sp3-bonded carbon stretching mode was observed in ultraviolet Raman spectra at around 1344–1367 cm−1 while no sp2-bonded carbon peak was simultaneously detected. By replacing bi-layer graphene with few-layer graphene, diamanoid/graphene hybrids were formed from the partial conversion of few-layer graphene, due to the prevalent Bernal stacking sequence. Raman spectroscopy, electron diffraction, and Density Functional Theory calculations show that partial conversion generates twisted bi-layer graphene located at the interface between the upper diamanoid domain and the non-converted graphenic domain underneath. Carbon-hydrogen bonding in the basal plane of hydrogenated few-layer graphene, where carbon is bonded to a single hydrogen over an area of 150 μm2, was directly evidenced by Fourier transform infrared microscopy and the actual full hydrogenation of diamane was supported by first-principle calculations. Those results open the door to large-scale production of diamane, diamanoids, and diamanoid/graphene hybrids.

Characterization of Biofilm Formation by Mycobacterium chimaera on Medical Device Materials.

Non-tuberculous mycobacteria (NTM) are widespread in the environment and are a public health concern due to their resistance to antimicrobial agents. The colonization of surgical heater-cooler devices (HCDs) by the slow-growing NTM species Mycobacterium chimaera has recently been linked to multiple invasive infections in patients worldwide. The resistance of M. chimaera to antimicrobials may be aided by a protective biofilm matrix of extracellular polymeric substances (EPS). This study explored the hypothesis that M. chimaera can form biofilms on medically relevant materials. Several M. chimaera strains, including two HCD isolates, were used to inoculate a panel of medical device materials. M. chimaera colonization of the surfaces was monitored for 6 weeks. M. chimaera formed a robust biofilm at the air-liquid interface of borosilicate glass tubes, which increased in mass over time. M. chimaera was observed by 3D Laser Scanning Microscopy to have motility during colonization, and form biofilms on stainless steel, titanium, silicone and polystyrene surfaces during the first week of inoculation. Scanning electron microscopy (SEM) of M. chimaera biofilms after 4 weeks of inoculation showed that M. chimaera cells were enclosed entirely in extracellular material, while cryo-preserved SEM samples further revealed that an ultrastructural component of the EPS matrix was a tangled mesh of 3D fiber-like projections connecting cells. Considering that slow-growing M. chimaera typically has culture times on the order of weeks, the microscopically observed ability to rapidly colonize stainless steel and titanium surfaces in as little as 24 h after inoculation is uncharacteristic. The insights that this study provides into M. chimaera colonization and biofilm formation of medical device materials are a significant advance in our fundamental understanding of M. chimaera surface interactions and have important implications for research into novel antimicrobial materials, designs and other approaches to help reduce the risk of infection.

Zinc alloys as prospective materials for biodegradable medical devices

Zinc-based materials are considered as promising materials for an application like biodegradable medical devices (bone fixations, stents). Such materials have to be characterized by an excellent combination of me-chanical, corrosion and biological properties. Presented paper is focused on the characterization of micro-structure and closely related mechanical properties for 3 zinc materials, namely pure Zn, Zn-0.8Mg and Zn-0.8Mg-0.2Sr. Studied alloys were prepared by gravity casting, homogenization treatment at 350 °C and extru-sion at 200 °C and extrusion ratio 11. Alloying by Mg caused the refinement of microstructure, formation of Mg2Zn11 phase and related improvement of mechanical properties like TYS and UTS for an extruded alloy. An additional encore of Sr causes a systematical improvement of TYS and UTS values, although the elonga-tion vas slightly decreased due to the presence of brittle SrZn13 phase.

Ретроспективный анализ разработок по использованию стерилизационных упаковочных материалов для медицинских изделий (обзор литературы)

The article discusses issues related to the creation and use of packaging materials for different types of products, including those specially designed for placing medical devices in them, before sterilization. The changes taking place related to the improvement of the barrier properties of packages to extend the preservation period of sterility of medical devices (both new types and complex in design) sterilized by different methods are noted. It is shown how over the course of several years new materials have been developed, technologies/methods of processing and reprocessing of raw materials and materials have changed, which make it possible to obtain packaging materials of different chemical nature and properties. Changes in existing packages from traditional materials (metal) to of single-use sterilization packages of a new generation with improved manufacturing technologies that provide mechanical, barrier and antimicrobial properties of packages differing in types, sizes, material properties are noted. The priority in the use of packaging materials for medical devices remains for materials that meet the requirements of GOST ISO 11607 "Packaging for medical devices subject to terminal sterilization", since the standard imposes more stringent requirements for the execution of packaging materials.

Interpenetration of metal cations into polyelectrolyte-multilayer-films via layer-by-layer assembly: Selective antibacterial functionality of cationic guar gum/ polyacrylic acid- Ag+ nanofilm against resistant E. coli

There is an urging need for the development of effective coating systems to avoid the rapidly growing resistant bacterial strains on medical devices surfaces that causes nosocomial infections. To this end, we studied the interpenetration of metal ions into polysaccharide thin films. Using several types of polyelectrolyte multilayer (PEM) films constructed from polycations; Quaternized cellulose (QC) and Cationic guar gum (CGG), and poly anions; Carboxymethyl cellulose (CMC) and Polyacrylic acid (PAA), we found that doping of Cu2+, Fe2+ and Ag+ metal ions into PEM matrix occurred through the interactions with polyacids groups. The fabricated thin films were characterized before and after metal interpenetration by FTIR, XRD, SEM, EDX, UV–vis, and optical reflectometry (OR). In comparison to QC/CMC and CGG/CMC thin films, CGG/PAA system exhibited maximum metal loading capacity confirmed by EDX and UV–vis, and 75 % reduction in thickness (215−290 nm) confirmed by OR. Ag+ loaded CGG/PAA nanofilm exhibited a robust antibacterial activity as 50-folds than Fe2+ and 150-folds than Cu2+, against resistant E. coli bacteria via down regulation of erm and β-Lactamase resistance gene expression. Which highlights the efficacy of CGG/PAA-Ag+ as an attractive antibacterial coating material for medical devices.

An in-vitro medical device material biocompatibility study using primary cell cultures of rat osteoblasts

<p class="abstract"><strong>Background:</strong> We questioned if simple chemical methods could be applied as a possible biocompatibility test for biomaterials.</p><p class="abstract"><strong>Methods:</strong> In a qualitative experiment, osteoblasts cells harvested from newly born (3-5) day old sprague-dawley rats were cultivated in growth medium in a controlled environment in the presence of titanium (Ti) (American Elements®), cobalt-chromium (Co-Cr) (Nobilium®), bio-activated rattan wood, orthopaedic bone cement (CEMEX®), implant fixtures (Astra TDC), and resorbable suture material (Poly-Gly-Lac) (VICRYL®). Sample aliquots were withdrawn periodically over 16 days. One and two-dimensional polyacrylamide gel electrophoresis (PAGE) as well as isoelectric focusing (IEF) produced spots that were subjected to enzyme digestion and molecular weight determination. In a follow-up quantitative experiment, the same samples, except for those containing CEMEX and VICRYL, were prepared. The alkaline phosphatase (ALP) activity was monitored continuously using the colorimetric Stanbio® kits. The ALP activities at days 2, 4, 8, 12, and 16, designated as a longitudinal variable, TIME, were analysed, using SPSS V.22, as a mixed ANOVA model with TIME as a repeated measure and the material type as an independent factor.</p><p class="abstract"><strong>Results:</strong> The IEF and second dimension PAGE produced an additional spot for Ti at pH(I) of 5-6. This was identified as IQUB_RAT IQ, a ubiquitin-like domain, molecular weight 2.6 kDa. This method was able to find finite differences in osteoblast activity after initial exposure to a foreign body. Both the ALP activity changes from one day to the next for all materials and the TIME-material type interaction effects were significant (p=0.000).</p><p class="abstract"><strong>Conclusions:</strong> This technique is suitable for use with human cell lines or clones. Experiments like these reduce the need for animal testing. </p>

Progress in the Applications of Smart Piezoelectric Materials for Medical Devices.

Smart piezoelectric materials are of great interest due to their unique properties. Piezoelectric materials can transform mechanical energy into electricity and vice versa. There are mono and polycrystals (piezoceramics), polymers, and composites in the group of piezoelectric materials. Recent years show progress in the applications of piezoelectric materials in biomedical devices due to their biocompatibility and biodegradability. Medical devices such as actuators and sensors, energy harvesting devices, and active scaffolds for neural tissue engineering are continually explored. Sensors and actuators from piezoelectric materials can convert flow rate, pressure, etc., to generate energy or consume it. This paper consists of using smart materials to design medical devices and provide a greater understanding of the piezoelectric effect in the medical industry presently. A greater understanding of piezoelectricity is necessary regarding the future development and industry challenges.

Functionalized carbon nanotubes based thermo-responsive shape memory blends with enhanced mechanical properties for potential robotics applications

A two-step approach was used to synthesize a thermo-responsive polyurethane and its blends with amino-functionalized-polystyrene (PS) and multiwall carbon nanotubes (MWCNTs) aiming at enhanced mechanical, thermal and shape memory properties. The synthesis of novel shape-memory polyurethane was confirmed by FTIR spectroscopy. SEM analysis of samples revealed excellent interfacial interaction due to chemical and physical interlinking between both polymers (PU synthesized and polystyrene functionalized) and functionalized multiwall carbon nanotubes (FMWCNTs) filler. The significant improvement in mechanical and thermal properties was observed for synthesized blends (PU/modified PS) as the filler content increased. The mechanical properties of PU/modified-PS blend having 3% loading amount of FMWCNTs were enhanced from 28.6 to 59.3 MPa as compared to those of neat PU. Due to proper fabrication and strong interfacial interaction, enhancement in thermal properties was also evident from the results with increasing filler loading amount. A sharp decrease in thermal, mechanical and recovery properties was also evident due to agglomerates net-points formation when loading amount of carbon filler increased from a certain level. Almost 100% shape recoveries were achieved for all samples, but the recovery durations of the samples were different. Modified-PS and FMWCNTs with PU formed three-dimensional interlocked networks which provided excellent mechanical strength, thermal stabilities and efficient shape recovery to the synthesized blends. Shape recovery response time of blends and nanocomposite was also found to decrease almost half of that of the pristine PU (less than 37 s for blends). Enhanced thermal stabilities, tensile properties, smaller shape recovery time, almost 100% shape recovery capabilities and sustainability, all factors favor the potential use of these blended composite materials in robotics, aeronautics, medical devices and high-performance materials in auto-industry.

In vitro methodology for medical device material thrombogenicity assessments: A use condition and bioanalytical proof-of-concept approach.

Device manufacturers and regulatory agencies currently utilize expensive and often inconclusive in vivo vascular implant models to assess implant material thrombogenicity. We report an in vitro thrombogenicity assessment methodology where test materials (polyethylene, Elasthane™ 80A polyurethane, Pebax®), alongside positive (borosilicate glass) and negative (no material) controls, were exposed to fresh human blood, with attention to common blood‐contact use conditions and the variables: material (M), material surface modification (SM) with heparin, model (Mo), time (T), blood donor (D), exposure ratio (ER; cm2 material/ml blood), heparin anticoagulation (H), and blood draw/fill technique (DT). Two models were used: (1) a gentle‐agitation test tube model and (2) a pulsatile flow closed‐loop model. Thrombogenicity measurements included thrombin generation (thrombin‐antithrombin complex [TAT] and human prothrombin fragment F1.2), platelet activation (β‐thromboglobulin), and platelet counts. We report that: (a) thrombogenicity was strongly dependent (p < .0001) on M, H, and T, and variably dependent (p < .0001 – > .05) on Mo, SM, and D (b) differences between positive control, test, and negative control materials became less pronounced as H increased from 0.6 to 2.0 U/ml, and (c) in vitro‐to‐in vivo case comparisons showed consistency in thrombogenicity rankings on materials classified to be of low, moderate, and high concern. In vitro methods using fresh human blood are therefore scientifically sound and cost effective compared to in vivo methods for screening intravascular materials and devices for thrombogenicity.

Implementation of Adverse event surveillance system in a Tunisian tertiary care hospital (2018-2019)

Abstract Background We found a high incidence of Adverse Events (AEs) following a survey conducted at Sahloul Hospital. Therefore, a surveillance system of AEs was implemented as a part of the implementation of the quality and risk management approach at Sahloul hospital, since April 2018. The aim of this study was to describe results of this system between May 2018 and April 2019. Methods It is a descriptive longitudinal study conducted at the Sahloul Hospital for a period of one year from May 1st, 2018 to April 30, 2019. Each service is provided with a data sheet that allows staff to report each adverse event they have witnessed. This does not include AEs that are part of alertness, blood exposure accidents or occupational accidents, or nosocomial infections which are assessed by specific circuits already in place. Results During the follow-up period, 93 AEs were reported. These AEs predominate in the sterilization unit followed by medical resuscitation and nephrology department with respective rates of 17.2%, 12.9% and 11.8%. The most frequent AEs were for maintenance (21.5%), medical device disinfection (20.5%), material resources (16.1%), and human resources (8.6%). According to criticality, the majority of AEs are tolerable under control (41.9%), unacceptable in 33.3% of cases and acceptable in 24.7% of cases. Conclusions In order to ensure proper functioning of the AEs surveillance and reporting system, the awareness of health professionals and their training would be essential. Quality of the information to be reported represents a challenge to be met to enable the planning, implementation and evaluation of improvement actions. Experience feedback would be with considerable benefit to improve the quality of professional practices. Key messages Surveillance and reporting system data analysis allow to identify mecanisms of the occurence of adverse events. Experience feedback is with considerable benefit to improve the quality of professional practices.

Polymer materials as promoters/inhibitors of amyloid fibril formation

Polymers are omnipresent materials that are widely used in medicine, e.g., as construction materials for medical devices or as polymer nanoparticle drug delivery systems. Therefore, their possible effects on biomolecules, such as lipids, proteins, and other molecules, present in the human body must be examined. This review addresses the effects of polymer materials (such as dendrimers, polysaccharides) on the process of amyloid fibril formation. Amyloidoses are very serious diseases that are characterized by amyloid deposition in various organs and tissues, causing their dysfunction. The treatment of amyloidoses, such as Alzheimer’s disease (AD), using polymer materials is a challenge. Studies aiming to elucidate the effects of polymers on the process of amyloid fibril formation are therefore also of key importance for understanding the process of amyloid fibril formation and amyloidoses in general.

Dual-functional anti-adhesion barrier prepared using micro-hierarchical structured and neutralized shellac films for drug release

Micro-hierarchical structured shellac films were prepared using a solution casting method with dodecyltrichloro-immobilized shellac microparticles. We evaluated two opposite surfaces of the shellac films—one a micro-hierarchical structured side and the other a neutralized shellac side using alkali ethanol—for their applications in the medical field. A bending strength test using a tensile strength testing machine and measurement of surface hardness using a scratch hardness tester indicated that the optimal composition of the base films comprised 15% shellac and 10% calcium phosphate as durability promoting agents. Further, dodecyltrichloro-immobilized shellac microparticles were synthesized and spray-deposited on the films. The solubility of shellac increased as the pH of the shellac solution increased. Analyses of cell adhesion, proliferation, and anti-thrombus efficiency were performed using a WST assay, field emission scanning electron microscope, and hemocytometer. The contact angle with the micro-hierarchical structure surface was approximately 150°. The spray-deposited shellac film yielded a lower cell and platelet adhesion rate (20%) than the untreated film. These results indicate that the micro-hierarchical structure has unique properties and that this novel superhydrophobic biodegradable shellac film can be applied as a blood/tissue-compatible, biodegradable material for implantable medical devices that need an anti-adhesion barrier.