Emerging membrane technologies and disinfection methods for efficient removal of waterborne pathogens during the COVID-19 pandemic and post-pandemic

Viruses and other microorganisms can enter water sources from different routes and cause pollution and irreparable damage. So, cost-effective and efficient systems for providing safe water are necessary. Efficient filtration systems based on antimicrobial materials have received a lot of attention in this regard. A wide range of materials play an important role in the production of efficient water filtration systems. Metal and metal oxide particles with anti-viral and antimicrobial properties comprising Cu, Cu2O, Ag, TiO2, and ZnO play a valuable role in the preparation of water filtration systems. Biopolymers such as cellulose or carbon nanomaterials like graphene or its derivatives have been reported to provide safe water. In this review, we summarize the use of diverse materials in the preparation of efficient filtration-based systems like membranes and paper filters for water treatment. Pathogen-containing water samples were effectively disinfected using the prepared water disinfection systems.Copyright © 2023 The Royal Society of Chemistry.

Intelligent medicine and beyond

With the developments of medical artificial intelligence (AI), meta-data analysis, intelligence-aided drug design and discovery, surgical robots and image-navigated precision treatments, intelligent medicine (IM) as a new era evolved from ancient medicine and biomedical medicine, has become an emerging topic and important criteria for clinical applications. It is fully characterized by fundamental research-driven, new-generation technique-directed as well as state-of-the-art paradigms for advanced disease diagnosis and therapy leading to an even broader future of modern medicine. As a fundamental subject and also a practice-oriented field, intelligent medicine is highly trans-disciplinary and cross-developed, which has emerged the knowledge of modern medicine, basic sciences and engineering. Basically, intelligent medicine has three domains of intelligent biomaterials, intelligent devices and intelligent techniques. Intelligent biomaterials derive from traditional biomedical materials, and currently are endowed with multiple functionalities for medical uses. For example, micro-/nanorobots, smart responsive biomaterials and digital drugs are representative intelligent biomaterials which have been already commercialized and applied to clinical uses. Intelligent devices, such as surgical robots, rehabilitation robots and medical powered exoskeleton, are an important majority in the family of intelligent medicine. Intelligent biomaterials and intelligent devices are more and more closely integrated with each other especially on the occasions of intelligence acquisition, remote transmission, AI-aided analysis and management. In comparison, intelligent techniques are internalized in the former two domains and are playing a critical role in the development of intelligent medicine. Representative intelligent techniques of telemedicine, image-navigated surgery, virtual/augmented reality and AI-assisted image analysis for early-stage disease assessments have been employed in nowadays clinical operations which to a large extent relieved medical labors. In the past decades, China has been in the leading groups compared to international colleagues in the arena of intelligent medicine, and a series of eminent research has been clinically translated for practical uses in China. For instance, the first 5G-aided remote surgery has been realized in Fujian Province in January 2019, which for the first time validated their applicability for human uses. The surgical robots have found China as the most vigorous market, and more than 10 famous Chinese companies are developing versatile surgical robots for both Chinese people and people all over the world. China also applied AI techniques to new drug developments especially in early 2020 when COVID-19 epidemic roared, and several active molecules and drug motifs have been discovered for early-stage COVID-19 screening and treatments. Based on the significance of intelligent medicine and its rapid developments in both basic research and industrials, this review summarized the comprehensive viewpoints of the Y6 Xiangshan Science Conferences titled with Fundamental Principles and Key Technologies of Intelligent Medicine, and gave an in-depth discussion on main perspectives of future developments of the integration of biomaterial and devices, the integration of bioinformatics and medical hardware, and the synergy of biotechnology and intelligence information. It is expected that this featuring article will further promote intelligent medicine to an even broader community not only for scientists but also for industrials, and in the long run embrace a perspective future for its blooming and rich contributions in China in the coming 5 years. © 2023 Chinese Academy of Sciences. All rights reserved.

WCN23-1206 Glomerulopathies Biobank in Uruguay. Description of the first 110 patients enrolled

Introduction: The incidence of glomerular diseases varies across different countries and criteria for kidney biopsy has changed over time. In Uruguay, glomerular diseases (GD) are a frequent cause of end stage kidney disease (ESKD) and renal replacement therapy with an annual incidence of 25.0 patients per million population according to data from the Uruguayan Dialysis Registry (UDR, year 2020). Since 1970, the Uruguayan Registry of Glomerulopathies has been recording the incidence, epidemiology and evolution of patients with GP in our country. In 2018, the Glomerulopathies Biobank (GB) began to operate including all patients with a native kidney biopsy performed at the Nephrology Department of the teaching hospital Hospital de Clinicas in Montevideo, Uruguay. The purpose of the BG is to record the phenotype (clinical and paraclinical) of patients with GD diagnosed by renal biopsy and at the same time store blood, urine, renal tissue and DNA samples. The aim of this report is to communicate the first 110 patients enrolled in the BG, which started in February 2018. Method(s): The BG protocol includes the collection of patronymic data, personal history, and clinical and paraclinical features of renal pathology. Plasma, urine and cell samples are stored for subsequent DNA extraction at the time of the kidney biopsy. In our country, all renal biopsies are performed by nephrologists. The Glomerular Biobank project is funded by the Nephrology Research Fund (School of Medicine, University of the Repubic) and was approved by the Ethics Committee of the Hospital de Clinicas and the Regulatory Verification Unit of the National Institute of Donation and Transplantation. The results are presented as mean and standard deviation (SD) for the continuous variables;and qualitative variables are described with percentages. Result(s): Patient recruitment began in February 2018 and we have recruited 110 patients. The mean age at the time of biopsy was 38.3+/-16.1 (min:16;max:78) years. Regarding sex distribution, the female sex slightly predominated (55.3%). Plasma creatinine was 2.1+/-1.45 mg/dL, proteinuria was 3.1+/-3.7 gr/dL and albuminaemia was 3.2+/-1.0 mg/dL. Microhaematuria was present in 61% of patients in the sediment study. Figure 1 shows the negative impact of the COVID 19 pandemic on the incidence of patients undergoing kidney biopsy. IgA nephropathy (13,8%)was the most frequent primary glomerular disease, followed by d focal and segmental glomerulosclerosis and membranous nephropathy. Consernig the glomerulopathies secondary to a systemic disease, the most frequent diagnosis was lupus nephritis (34,5%) followed by vasculitis, amyloidosis and diabetes. Conclusion(s): Having a prospective cohort of patients with glomerular disease, including reliable data and biological samples, will allow us to perform clinical and epidemiological analyses quickly and reliably in the future. The data and aliquots of biological material are available to any local nephrologist who proposes a hypothesis and has the approval of the corresponding ethics committee. The medium-term objective is to incorporate other national reference institutions in the care of patients with glomerular diseases. The data collected by the Glomerular Biobank will be a valuable input to the process of continuous improvement, and will serve as a basis for future nephrological research of excellence. No conflict of interestCopyright © 2023

Recent advances in regenerative biomaterials.

Nowadays, biomaterials have evolved from the inert supports or functional substitutes to the bioactive materials able to trigger or promote the regenerative potential of tissues. The interdisciplinary progress has broadened the definition of 'biomaterials', and a typical new insight is the concept of tissue induction biomaterials. The term 'regenerative biomaterials' and thus the contents of this article are relevant to yet beyond tissue induction biomaterials. This review summarizes the recent progress of medical materials including metals, ceramics, hydrogels, other polymers and bio-derived materials. As the application aspects are concerned, this article introduces regenerative biomaterials for bone and cartilage regeneration, cardiovascular repair, 3D bioprinting, wound healing and medical cosmetology. Cell-biomaterial interactions are highlighted. Since the global pandemic of coronavirus disease 2019, the review particularly mentions biomaterials for public health emergency. In the last section, perspectives are suggested: (i) creation of new materials is the source of innovation; (ii) modification of existing materials is an effective strategy for performance improvement; (iii) biomaterial degradation and tissue regeneration are required to be harmonious with each other; (iv) host responses can significantly influence the clinical outcomes; (v) the long-term outcomes should be paid more attention to; (vi) the noninvasive approaches for monitoring in vivo dynamic evolution are required to be developed; (vii) public health emergencies call for more research and development of biomaterials; and (viii) clinical translation needs to be pushed forward in a full-chain way. In the future, more new insights are expected to be shed into the brilliant field-regenerative biomaterials.

Synthesis of ester-free poly(trimethylene carbonate) bearing cinnamyl moiety for antibacterial biomaterials applications

Antimicrobial biocompatible polymers have highly desirable materials in medical technology to prevent any healthcare-associated infections from the in-dwelling on medical device that could pose a risk to patients, and this is gaining attention particularly in the context of the current COVID-19 pandemic. In this study, ester free type of poly(trimethylene carbonate) (PTMC) derivatives containing cinnamyl group has been synthesized. Also, several of alcohol-based initiators;benzyl alcohol, 2,2-dimethyl-1-propanol, 4-(2-hydroxyethoxy) benzaldehyde and 2-(p-tolyloxy)ethan-1-ol and polymer structure has been designed and analyzed its molecular weight on thermal and physical properties effect. The homopolymers and copolymers of PTMC derivatives with cinnamyl group had achieved with molecular weight up to 7400 — 12,300 g/mol with the improved physical state and glass transition temperature, Tg at 8 ֩C respectively. Different types of essential oil, which is thymol and carvacrol, have been incorporated with cinnamyl PTMC had resulted the suppression of E.coli and S.aureus growth. The results showed a promising of introduction of cinnamyl derivatives into ester free-type of PTMC derivatives, as well as create more alcohol-initiators for polymerization of trimethylene carbonate, for more advanced development in the future. © 2023 Elsevier B.V.

Liquid Crystalline Systems from Nature and Interaction of Living Organisms with Liquid Crystals.

Biomaterials, which are substances interacting with biological systems, have been extensively explored to understand living organisms and obtain scientific inspiration (such as biomimetics). However, many aspects of biomaterials have yet to be fully understood. Because liquid crystalline phases are ubiquitously found in biomaterials (e.g., cholesterol, amphiphile, DNA, cellulose, bacteria), therefore, a wide range of research has made attempts to approach unresolved issues with the concept of liquid crystals (LCs). This review presents these studies that address the interactive correlation between biomaterials and LCs. Specifically, intrinsic LC behavior of various biomaterials such as DNA, cellulose nanocrystals, and bacteriaare first introduced. Second, the dynamics of bacteria in LC media are addressed, with focus on how bacteria interact with LCs, and how dynamics of bacteria can be controlled by exploiting the characteristics of LCs. Lastly, how the strong correlation between LCs and biomaterials has been leveraged to design a new class of biosensors with additional functionalities (e.g., self-regulated drug release) that are not available in previous systems is reviewed. Examples addressed in this review convey the message that the intersection between biomaterials and LCs offers deep insights into fundamental understanding of biomaterials, and provides resources for development of transformative technologies.

A Biomimetic, Silaffin R5-Based Antigen Delivery Platform.

Nature offers a wide range of evolutionary optimized materials that combine unique properties with intrinsic biocompatibility and that can be exploited as biomimetic materials. The R5 and RRIL peptides employed here are derived from silaffin proteins that play a crucial role in the biomineralization of marine diatom silica shells and are also able to form silica materials in vitro. Here, we demonstrate the application of biomimetic silica particles as a vaccine delivery and adjuvant platform by linking the precipitating peptides R5 and the RRIL motif to a variety of peptide antigens. The resulting antigen-loaded silica particles combine the advantages of biomaterial-based vaccines with the proven intracellular uptake of silica particles. These particles induce NETosis in human neutrophils as well as IL-6 and TNF-α secretion in murine bone marrow-derived dendritic cells.

BIOCOLLABORATIONS IN THE DESIGN PROCESS: A PILOT EXPERIMENT ON THE PRODUCTION OF MASK FROM MICROBIAL CELLULOSE

The growth of cities, the excessive use of natural resources, and the agglomeration of undegradable materials in nature are very common problems in recent years and whose results are seen more and more every day. Latest, with the "Covid-19" pandemic, which was declared as a global epidemic in 2020, petroleum-based medical masks with disposable and non-biodegradable properties became one of the most used products. This situation has led to an increase in the damage to the environment. The aim of this study is to seek for an environmentally friendly alternative to medical masks that are frequently used in daily life by incorporating biocollaborative approaches into the design process. In this direction, the microbial cellulose application obtained by the symbiotic culture of bacteria and yeast was used to create the surface. The use of microbial cellulose in design-related fields is a topic that is only recently becoming widespread and researched. There is not much academic research in this field, especially on a national scale, and the article aims to contribute to the literature in this context. The recipe of the mask consists of easily accessible materials to be easily produced in the home environment and Kombucha culture was used as a source of microbial cellulose. During the experiment process, different experimental environments and coloring experiments were made, and a mask design with origami folding was carried out to take the shape of the human face more easily as a final product, to enrich the potential for folding and its aesthetic appearance. The medical use of the developed mask, the efficiency of use and the physical properties of the surface require detailed analysis and research. As a result, within the scope of this study, an environmentally friendly alternative to conventional methods for medical masks has been presented and the potential of microbial cellulose to replace plastic-based masks has been revealed. Using growing biomaterials and incorporating them into the design field can be a unique opportunity to use materials with a truly sustainable production method. © 2022. Tekstil ve Muhendis.All Rights Reserved

THE FIRST REPORT FROM THE NATIONAL COVID-19 AUTOPSY REGISTRY IN GERMANY

BACKGROUND AND AIMS: Autopsies are an invaluable tool in medicine for studying the pathophysiology of diseases, including kidney diseases and causes of death. To facilitate multicenter autopsy-based studies and to provide a single point of contact for data analysis and reporting, the German COVID-19 Autopsy Registry (DeRegCOVID) was launched in April 2020 to uncover effects on pulmonary (micro)vasculature, systemic viral spread including the kidneys or interaction with the immune system. METHOD: The electronic registry uses a web-based electronic data collection system. Participation is voluntary and biomaterial remains at each site (decentralized biobanking). As of October 2021, the registry included N = 1129 autopsy cases with 69 271 individual data points containing information on 18 674 available biospecimens, including kidneys as part of the standard sampling protocol, collected at 29 German sites. RESULTS: In the N = 1095 eligible records, the male-to-female ratio was 1-8:1, with peaks at 65-69 and 80-84 years in men and >85 years in women. Analysis of the chain of events leading directly to death showed that in 86% of autopsy cases, COVID-19 was the actual cause of death, whereas in 14% of cases, COVID- 19 was a concomitant disease. The most common immediate cause of death was diffuse alveolar injury/acute respiratory distress syndrome, followed by multiorgan failure, including the kidneys. The registry supports several scientific projects, informs the public and provides reports to federal health authorities, which led to a change in the German Infection Protection Act and facilitated autopsies during pandemics. CONCLUSION: A national autopsy registry can provide multicenter quantitative information on COVID-19 deaths at the national level to support medical research, policy decisions and public discussions. Previous and ongoing studies also showed the potential of autopsies for nephrology research.

Therapeutic potential of targeting galectins - A biomaterials-focused perspective.

Among all the biological entities involved in the immune response, galectins, a family of glycan-binding proteins, have been described as key in immune cell homeostasis and modulation. More importantly, only some galectin family members are crucial in the resolution of inflammation, while others perpetuate the immune response in a pathological context. As they are expressed in most major diseases, their potential as targets for new therapies seems promising. Most of the galectin family members' ubiquitous expression points to the need for targeted treatments to ensure effectiveness. Engineered biomaterials are emerging as a promising method to improve galectin-targeted strategies' therapeutic performance. In this review, we provide an overview of the role of galectins in health and disease and their potential as therapeutic targets, as well as the state-of-the-art and future directions of galectin-targeted biomaterials.

Therapeutic Treatments for Osteoporosis-Which Combination of Pills Is the Best among the Bad?

Osteoporosis is a chronical, systemic skeletal disorder characterized by an increase in bone resorption, which leads to reduced bone density. The reduction in bone mineral density and therefore low bone mass results in an increased risk of fractures. Osteoporosis is caused by an imbalance in the normally strictly regulated bone homeostasis. This imbalance is caused by overactive bone-resorbing osteoclasts, while bone-synthesizing osteoblasts do not compensate for this. In this review, the mechanism is presented, underlined by in vitro and animal models to investigate this imbalance as well as the current status of clinical trials. Furthermore, new therapeutic strategies for osteoporosis are presented, such as anabolic treatments and catabolic treatments and treatments using biomaterials and biomolecules. Another focus is on new combination therapies with multiple drugs which are currently considered more beneficial for the treatment of osteoporosis than monotherapies. Taken together, this review starts with an overview and ends with the newest approaches for osteoporosis therapies and a future perspective not presented so far.

BIOFABRICATION OF NANOSTRUCTURED GELATIN FIBER VIA CENTRIFUGAL SPINNING METHOD

In this study, type-I bovine collagen solved in diluted acidic solutions (acidic acid and formic acid) and fed into the centrifugal spinning device to obtain nanofiber formation. The centrifugal spinning device is providing submicron fibers thanks to its rotational movement during the solution feeding. Different feeding ratios and rotational speeds are studied to optimize the process. Obtained na nofiber webs were observed via scanning electron microscopy (SEM). Structural characterization of samples was investigated via FTIR. Fabricated collagen-based nanofibers filtration performance was evaluated in terms of filtration efficiency and air permeability tests. Tests results are pointed that fabricated gelatin nanofibers can be an efficient alternative biomaterial design against Covid-19.

The Impact of mRNA Technology in Regenerative Therapy: Lessons for Oral Tissue Regeneration.

Oral tissue regeneration following chronic diseases and injuries is limited by the natural endogenous wound-healing process. Current regenerative approaches implement exogenous systems, including stem cells, scaffolds, growth factors, and plasmid DNA/viral vectors, that induce variable clinical outcomes. An innovative approach that is safe, effective, and inexpensive is needed. The lipid nanoparticle-encapsulated nucleoside-modified messenger RNA (mRNA) platform has proven to be a successful vaccine modality against coronavirus disease 2019, demonstrating safety and high efficacy in humans. The same fundamental technology platform could be applied to facilitate the development of mRNA-based regenerative therapy. While the platform has not yet been studied in the field of oral tissue regeneration, mRNA therapeutics encoding growth factors have been evaluated and demonstrated promising findings in various models of soft and hard tissue regeneration such as myocardial infarction, diabetic wound healing, and calvarial and femoral bone defects. Because restoration of both soft and hard tissues is crucial to oral tissue physiology, this new therapeutic modality may help to overcome challenges associated with the reconstruction of the unique and complex architecture of oral tissues. This review discusses mRNA therapeutics with an emphasis on findings and lessons in different regenerative animal models, and it speculates how we can apply mRNA-based platforms for oral tissue regeneration.

Special Features of Polyester-Based Materials for Medical Applications.

This article presents current possibilities of using polyester-based materials in hard and soft tissue engineering, wound dressings, surgical implants, vascular reconstructive surgery, ophthalmology, and other medical applications. The review summarizes the recent literature on the key features of processing methods and potential suitable combinations of polyester-based materials with improved physicochemical and biological properties that meet the specific requirements for selected medical fields. The polyester materials used in multiresistant infection prevention, including during the COVID-19 pandemic, as well as aspects covering environmental concerns, current risks and limitations, and potential future directions are also addressed. Depending on the different features of polyester types, as well as their specific medical applications, it can be generally estimated that 25-50% polyesters are used in the medical field, while an increase of at least 20% has been achieved since the COVID-19 pandemic started. The remaining percentage is provided by other types of natural or synthetic polymers; i.e., 25% polyolefins in personal protection equipment (PPE).

Periodic thermomechanical modulation of toll-like receptor expression and distribution in mesenchymal stromal cells.

ABSTRACT: Toll-like receptor (TLR) can trigger an immune response against virus including SARS-CoV-2. TLR expression/distribution is varying in mesenchymal stromal cells (MSCs) depending on their culture environments. Here, to explore the effect of periodic thermomechanical cues on TLRs, thermally controlled shape-memory polymer sheets with programmable actuation capacity were created. The proportion of MSCs expressing SARS-CoV-2-associated TLRs was increased upon stimulation. The TLR4/7 colocalization was promoted and retained in the endoplasmic reticula. The TLR redistribution was driven by myosin-mediated F-actin assembly. These results highlight the potential of boosting the immunity for combating COVID-19 via thermomechanical preconditioning of MSCs. GRAPHIC ABSTRACT: Periodic thermal and synchronous mechanical stimuli provided by polymer sheet actuators selectively promoted the expression of SARS-CoV-2-associated TLRs 4 and 7 in adipose-derived MSCs and recruited TLR4 to Endoplasmic reticulum region where TLR7 was located via controlling myosin-mediated F-actin cytoskeleton assembly.

Freeze-dried human placental mesenchymal stem cell prevents the progression of acute respiratory distress syndrome in rats

Introduction: Acute respiratory distress syndrome (ARDS) is one of the main causes of mortality in patients with COVID-19. Despite numerous studies, therapies for ARDS in COVID-19 remain significantly limited. Currently, there have been reports of the efficient use of mesenchymal stem cell (MSC) for the treatment of ARDS. Several studies have reported that MSC produces antiinflammatory cytokines, promotes the maturation of dendritic cells, and modulates NK cells. The safety of MSC therapy has been demonstrated in early-stage clinical studies with a relatively small number of patients. We investigated the influence of freeze-dried human placental mesenchymal stem cells (HPMSC) in a preclinical rodent model of ARDS. Methods: Sixty rats were randomly divided into three groups of 20: the first group was the control, the second group received dexamethasone, and the third group received HPMSC. Results: Survival was highest in the HPMSC group (75%, 95%CI: 50, 88) when compared to the control group. In a cox regression model, mortality of HPMSC group (HR: 11.30 [95% CI: 4.05, 31.50]) when compared to control was statistically significant (p < 0.001). Mortality in the dexamethasone (HR: 64.25 [95% CI: 32.71, 126.19]) was not statistically significant (p = 0.199). Plasma serum TNF-α levels were statistically significant in the HMPSC group when compared to the control (p < 0.001) and dexamethasone group (p < 0.001). Single factor ANOVA comparing TNF-α levels between all groups was also significant (p < 0.0001). Trends (Table 1) indicated that plasma serum cytokine levels for TNF-α, IL-1β, and Il-6 were less in the HPMSC group than the control and dexamethasone groups. Conclusions: These experiments demonstrated that HPMSC significantly decreased mortality, endogenous intoxication, and a reduction in the release of pro-inflammatory cytokines. The freezedried placental stem cell is a promising biomaterial that can be used nebulized for the treatment of coronavirus disease.

Biomaterial-assisted biotherapy: A brief review of biomaterials used in drug delivery, vaccine development, gene therapy, and stem cell therapy.

Biotherapy has recently become a hotspot research topic with encouraging prospects in various fields due to a wide range of treatments applications, as demonstrated in preclinical and clinical studies. However, the broad applications of biotherapy have been limited by critical challenges, including the lack of safe and efficient delivery systems and serious side effects. Due to the unique potentials of biomaterials, such as good biocompatibility and bioactive properties, biomaterial-assisted biotherapy has been demonstrated to be an attractive strategy. The biomaterial-based delivery systems possess sufficient packaging capacity and versatile functions, enabling a sustained and localized release of drugs at the target sites. Furthermore, the biomaterials can provide a niche with specific extracellular conditions for the proliferation, differentiation, attachment, and migration of stem cells, leading to tissue regeneration. In this review, the state-of-the-art studies on the applications of biomaterials in biotherapy, including drug delivery, vaccine development, gene therapy, and stem cell therapy, have been summarized. The challenges and an outlook of biomaterial-assisted biotherapies have also been discussed.

Durvalumab in frail and older patients with stage iv non-small cell lung cancer: The randomized phase ii duration trial

Introduction: Checkpoint inhibitors have recently been established as first-line treatment for metastatic NSCLC. Notably, a phenomenon known as immunosenescence, i.e. the progressive remodeling of the immune system with aging, as well as the inflammatory status, may interfere with the activity of PD-1/PD-L1 inhibitors. Although frail and older patients represent a major fraction of non-small cell lung cancer (NSCLC) patients in routine clinical practice, this population is still underrepresented in most clinical trials. Thus, clinical evidence about tolerability and efficacy of these novel agents in the elder and frail population is urgently required. Methods/Design: DURATION (NCT03345810) is a prospective, open label, treatment stratified, randomized, multicenter phase II study. The protocol foresaw the enrollment of 200 patients diagnosed with stage IV NSCLC ≥70 years old and/or with Charlson-Comorbidity Index > 1 and/ or with a performance status ECOG > 1. Patients were stratified according to Cancer and Age Research Group (CARG) score in 'fit' and 'less fit'. Patients were then randomized 1:1 to receive either CT or two cycles of CT followed by two cycles of durvalumab and durvalumab maintenance. Details are shown in figure 1. The primary endpoint is the rate of treatment-related grade III/IV adverse events. Secondary endpoints are progression-free survival, response rate and overall survival and quality of life assessment. The trial is accompanied by a biomaterial repository to explore potential biomarkers. Results: The last patient was enrolled in January 2021. Forty-nine, 48, 51, and 52 patients were allocated to arm A, arm B, arm C, and arm D, respectively. Currently, 145 patients have completed the study, 13 patients are under treatment (12 in total in durvalumab-maintenance arms and 1 in the CT arm), while 42 are in follow-up. Conclusions: Inspite of the COVID-19 pandemic, the DURATION trial successfully completed the planned enrollment of 200 patients, underlying the urgent need for evidence of efficacy and tolerability of immunotherapy in the challenging population of frail and elderly patients.

Accuracy of Impression Material During COVID-19 after Sterilization-In vitro Study

Aims: The goal of this research is to assess the effect of steam autoclave sterilization due to the impact of Covid-19 on the accuracy of the elastomer impression materials. Study Design: In vitro study. Place and Duration of Study: Department of oral and Maxillofacial Prosthodontics, King Abdul-Aziz University, Jeddah;Saudi Arabia, between June 2021 and November 2021. Methodology: The following materials were used in this study: fully dentate master cast, metal trays, elastomer impression material (addition silicon), type IV stone. Forte impressions made using the metal tray and elastomer impression materials. The impressions were separated equally into two groups: Control group (C.G), untreated impressions. Sterilized group (S.G): Impressions were sterilized by using the steam autoclave. To make stone castings for each group, they were poured with type IV stone. The traveling microscope was used to evaluate the impression material's dimensional accuracy and detail reproduction with and without autoclave sterilization. Results: The cross-arch distance (X) of the master model was measured (41.29 mm), While the cross arch distance (X) in the control group (C.G) of the untreated impressions had a mean and standard deviation of 41.492 +/- 0.150 mm. In the tested group (S.G) : the sterilized impression, we found the cross-arch distance (X) had a mean and standard deviation of 41.628 +/- 0.223 mm. The master model's Anteroposterior distance (A-P) was measured (21.12 mm). For the control group (C.G) : we found the mean and standard deviation value reading of the A-P distance were 20.899 +/- 0.79 mm. For (S.G) group: we found the mean and standard deviation reading of the A-P distance were 19.992 +/- 0.482 mm. Conclusion: Steam autoclave sterilization of the elastomer impression material should be considered carefully, especially when fabricating fixed partial dentures. If the impression material is to be used in making diagnostic castings, conventional steam autoclave sterilization of the elastomers impression material may be sufficient for patients.