Long-Term Safety and Efficacy Evaluation of Travoprost Intracameral Implant Based on Pooled Analyses from Two Phase III Trials.

AIM: The purpose of this study was to conduct and interpret a pooled 12-month analysis of two prospective, multi-center, randomized, double-masked, controlled trials designed to assess the efficacy and safety of the travoprost intracameral implant (slow-eluting [SE] implant in development as a new therapeutic and fast-eluting [FE] implant included for masking purposes) in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT). METHODS: Subjects with OAG or OHT, on 0-3 intraocular pressure (IOP)-lowering medications, baseline unmedicated mean diurnal IOP of ≥ 21 mmHg, and IOP ≤ 36 mmHg at each baseline diurnal timepoint, received either a travoprost implant and twice-daily (BID) placebo eye drops or BID timolol 0.5% eye drops and a sham procedure. Subjects were followed through 12 months and assessed for IOP, reduction in topical IOP-lowering medications, and safety parameters including treatment-emergent adverse events (TEAEs). IOP at 8AM was prospectively collected at all study visits through 12 months and diurnal IOP, measured at 8AM, 10AM, and 4PM, was prospectively collected at baseline, day 10, week 6, and months 3 and 12. RESULTS: A total of 1150 subjects were randomized (385 FE implant, 380 SE implant, and 385 sham/timolol) across the two trials. Statistical non-inferiority to timolol and clinically relevant reductions in 8AM IOPs were demonstrated at month 12. In more detail, both implant groups demonstrated statistical non-inferiority to timolol and clinically relevant reductions from baseline in mean diurnal IOP at all visits over the 12-month evaluation period when diurnal IOP was collected. Additionally, both implant groups demonstrated robust treatment effect based on 8AM average IOP from day 10 through the specified visit which ranged from day 10 to month 12 from 6.9 to 8.5 mmHg in the FE implant group; 6.8 to 8.5 mmHg in the SE implant group; and 7.3 to 7.5 mmHg in the sham/timolol group. With regards to reduction in topical pharmacotherapy, at month 12, 77.6% of FE and 81.4% of SE implant eyes were completely free of all topical IOP-lowering medications and a significantly greater proportion of FE and SE implant eyes (89.9% and 93.0%) versus sham/timolol eyes (66.9%) were on the same or fewer topical IOP-lowering medications compared with pre-study (p <  0.0001). Furthermore, of subjects on topical IOP medications at screening, a significantly greater proportion of FE implant (80.2%) and SE implant (85.1%) eyes versus sham/timolol (22.8%) eyes were on fewer topical IOP-lowering medications at month 12 compared with pre-study (p <  0.0001). Lastly, of SE implant eyes on same or fewer topical IOP-lowering medications at month 12, the average through month 12 decreased by 0.9 medications, and of those SE implant eyes on fewer topical IOP-lowering medications compared with pre-study, the average through month 12 decreased by 1.4 medications. The most common TEAEs related to study treatment were hyperemia (conjunctival or ocular), iritis, and IOP increased. CONCLUSION: The travoprost intracameral implant demonstrated robust IOP-lowering efficacy that was sustained and statistically non-inferior to timolol over the entire 12 months, resulting in a significant reduction in topical IOP-lowering medication use, with the majority of SE implant eyes remaining completely free of all topical IOP-lowering medications. In addition, the implant demonstrated a favorable safety and tolerability profile based on this pooled 12-month analysis of two pivotal trials. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT03519386 (registered May 09, 2018) and NCT03868124 (registered March 08, 2019).

Biocompatible melanin from the marine black yeast Hortaea werneckii R23 with antioxidant and photoprotection property.

Pigments from diverse sources have a great deal of interest due to its multifaceted applications. Hence, this study reports the physicochemical and functional characterization of the black pigment melanin from the marine black yeast Hortaea werneckii R23. In the present study, Hortaea werneckii R23, produced a black pigment in the yeast biomass. The pigment was extracted from the harvested yeast biomass and followed by pigment purification, characterization and identification was done. Physicochemical characterization of the pigment showed acid precipitation, alkali solubilization, insolubility in most organic solvents and water. The black pigment was confirmed as melanin based on ultraviolet-visible spectroscopy, Fourier-transform infrared, and Nuclear magnetic resonance spectroscopy analyses. Furthermore, the analyses of the elemental composition indicated that the pigment possessed a moderately high percentage of nitrogen and also detectable proportion of sulfur. All these Physicochemical properties indicated that H. werneckii melanin (HwM) mostly consisted of eumelanin. HwM exhibited strong antioxidant potential as reactive oxygen species (ROS) scavenger by in vitro DPPH (1,1-diphenyl-2-picryl hydrazyl) and ABTS (2,2-azinobis-3-ethyl-benzothiozoline-6-sulphonic acid) radical scavenging assay, and lipid peroxidation assay. The photoprotectant role of HwM on UV-irradiated human epithelial cells (HEp-2) revealed its potential effect in photoprotection. In addition, cytotoxicity study by XTT and SRB assay confirmed its biocompatibility with HEp-2 cells. From these findings, it is evident that the HwM from the marine black yeast possesses strong antioxidant and photoprotectant activity, moreover, it is biocompatible to human epithelial cells. So HwM could be used as a protective agent against oxidative stress associated disorders in an environment-friendly perspective.

Antibacterial Efficacy and Mechanisms of Action of a Novel Beta-Defensin from Snakehead Murrel, Channa striata.

Beta-defensins, identified from fishes, constitute a crucial category of antimicrobial peptides important in combating bacterial fish pathogens. The present investigation centers on the molecular and functional characterization of CsDef, a 63-amino acid beta-defensin antimicrobial peptide derived from snakehead murrel (Channa striata). The physicochemical attributes of CsDef align with the distinctive characteristics observed in AMPs. CsDef was recombinantly produced, and the recombinant peptide, rCsDef, exhibited notable antibacterial efficacy against bacterial fish pathogens with an MIC of 16 µM for V. proteolyticus. A. hydrophila exhibited 91% inhibition, E. tarda 92%, and V. harveyi 53% at 32 µM of rCsDef. The rCsDef exhibited a multifaceted mechanism of action against bacteria, i.e., through membrane depolarization, membrane permeabilization, and generation of ROS. The rCsDef was non-hemolytic to hRBCs and non-cytotoxic to normal mammalian cell line CHO-K1. However, it exhibited anticancer properties in MCF-7. rCsDef demonstrated notable stability with respect to pH, temperature, salt, metal ions, and proteases. These findings suggest it is a potential candidate molecule for prospective applications in aquaculture.

A Novel Beta-Defensin Isoform from Malabar Trevally, Carangoides malabaricus (Bloch & Schneider, 1801), an Arsenal Against Fish Bacterial Pathogens: Molecular Characterization, Recombinant Production, and Mechanism of Action.

Antimicrobial peptides (AMPs), including beta-defensin from fish, are a crucial class of peptide medicines. The focus of the current study is the molecular and functional attributes of CmDef, a 63-amino acid beta-defensin AMP from Malabar trevally, Carangoides malabaricus. This peptide demonstrated typical characteristics of AMPs, including hydrophobicity, amphipathic nature, and +2.8 net charge. The CmDef was recombinantly expressed and the recombinant peptide, rCmDef displayed a strong antimicrobial activity against bacterial fish pathogens with an MIC of 8 µM for V. proteolyticus and 32 µM for A. hydrophila. The E. tarda and V. harveyi showed an inhibition of 94% and 54%, respectively, at 32 µM concentration. No activity was observed against V. fluvialis and V. alginolyticus. The rCmDef has a multimode of action that exerts an antibacterial effect by membrane depolarization followed by membrane permeabilization and ROS production. rCmDef also exhibited anti-cancer activities in silico without causing hemolysis. The peptide demonstrated stability under various conditions, including different pH levels, temperatures, salts, and metal ions (KCl and CaCl2), and remained stable in the presence of proteases such as trypsin and proteinase K at concentrations up to 0.2 µg/100 µl. The strong antibacterial efficacy and non-cytotoxic nature suggest that rCmDef is a single-edged sword that can contribute significantly to aquaculture disease management.

An optimized protocol for routine development of cell culture from adult oyster, Crassostrea madrasensis.

Marine molluscan cell lines, required for virus screening and cultivation, form essential tools for developing health management strategies for these animals in the blue economy. Moreover, they are also crucial to develop cultivated seafood. As there is no valid marine molluscan cell line, primary cell cultures are relied upon for all investigations. A sound protocol for generating primary cell cultures from molluscs is entailed, but existing protocols often involve heavy antibiotic usage and depuration that invariably affect gene expression and cell health. This work presents an easy-to-adopt, time-saving protocol using non-depurated mollusc Crassostrea madrasensis, which requires only initial antibiotic treatment and minimal exposure or no use of antibiotics in the cell culture medium. The important experimental considerations for arriving at this protocol have been elucidated. Accordingly, sodium hypochlorite and neomycin sulfate were chosen for disinfecting tissues. The study is the first to use shrimp cell culture medium (SCCM) as a cell culture medium for molluscan cell culture. Despite being osmoconformers, the oysters exhibited stable intracellular osmotic conditions and pH, which, when provided in vitro, promoted effective cardiomyocyte formation. The cell viability could be enhanced using 10% fetal bovine serum (FBS), but healthy cell culture could also be obtained using SCCM without FBS. The optimized culture conditions allowed for regular beating cardiomyocyte clusters that could be retained for a month. Limited cell proliferation, as shown by the BrdU assay, demands further interventions, such as possibly producing induced pluripotent stem cells. The optimized protocol and culture conditions also align with some requirements for producing cultivated meat from marine molluscs.

Antibacterial activity and modes of action of a novel hepcidin isoform from the shrimp scad, Alepes djedaba (Forsskål, 1775).

Hepcidin, initially identified in human blood ultrafiltrate as cysteine rich Liver Expressed Antimicrobial Peptide (LEAP-1), is a core molecular conduit between iron trafficking and immune response. Though a great share of studies has been focused on the iron regulatory function of hepcidins, investigations on the antimicrobial aspects are relatively less. The present study is aimed at identification of hepcidin from a teleost fish, Alepes djedaba followed by its recombinant expression, testing antibacterial property, stability and evaluation of cytotoxicity. Modes of action on bacterial pathogens were also examined. A novel hepcidin isoform, Ad-Hep belonging to the HAMP1 (Hepcidin antimicrobial peptide 1) group of hepcidins was identified from the shrimp scad, Alepes djedaba. Ad-Hep with 2.9 kDa size was found to be a cysteine rich, cationic peptide (+4) with antiparallel beta sheet conformation, a furin cleavage site (RXXR) and 'ATCUN' motif. It was heterologously expressed in E. coli Rosettagami B(DE3)PLysS cells and the recombinant peptide, rAd-Hep was found to have significant antibacterial activity, especially against Edwardsiella tarda, Vibrio parahaemolyticus and Escherichia coli. Membrane depolarization followed by membrane permeabilization and Reactive Oxygen Species (ROS) production were found to be the modes of action of rAd-Hep on bacterial cells. Ad-Hep was found to be non-haemolytic to hRBC and non-cytotoxic in mammalian cell line. Stability of the peptide at varying temperature, pH and metal salts qualify them for applications in vivo. With significant bactericidal activity coupled with direct killing mechanisms, the rAd-Hep can be a promising drug candidate for therapeutic applications in medicine and fish culture systems.

Two-Year Performance and Safety Results of the MINIject Supraciliary Implant in Patients With Primary Open-Angle Glaucoma: Meta-Analysis of the STAR-I, II, III Trials.

PURPOSE: To evaluate the performance and safety of minimally invasive glaucoma surgery with a supraciliary drainage device (MINIject; iSTAR Medical, Wavre, Belgium) in primary open-angle glaucoma (POAG) as a stand-alone procedure. DESIGN: Meta-analysis. METHODS: At 11 sites in Colombia, France, Germany, India, Panama, and Spain, 82 patients were treated in 3 prospective, multicenter, interventional, nonrandomized trials (STAR-I, II, III). Data were pooled in a meta-analysis of up to 2 years of follow-up postimplantation. The main outcome measures were mean relative and absolute reduction in diurnal intraocular pressure (IOP) compared to baseline. Secondary outcomes included patients with IOP ≤18 mmHg, patients with IOP reduction ≥20%, number of IOP-lowering medications, adverse events, and endothelial cell density loss. RESULTS: At the 2-year follow-up (n = 66), mean IOP was reduced from 23.8 ± 3.3 mmHg at baseline to 14.4 ± 4.5 mmHg (-39.3%; P < 0.0001). An IOP reduction of ≥20% was achieved in 89.4% of patients, with 84.8% having an IOP ≤18 mmHg. IOP-lowering medications were reduced from a mean of 2.4 ± 1.1 to 1.4 ± 1.4 (P < 0.0001), with 37.9% of patients being medication-free at 2 years. Mean endothelial cell density loss at 2 years was 6.2 ± 9.1% compared to baseline and no patient had a loss >30%. CONCLUSIONS: This meta-analysis demonstrates the favorable safety and efficacy profile of a supraciliary device implanted in a stand-alone, ab-interno procedure in patients with mild-to-moderate POAG. The data demonstrate that MINIject is a safe and effective, bleb-free treatment option for patients requiring low target IOP up to 2 years.

Residual Pattern of Chlorantraniliprole, Thiamethoxam, Flubendiamide and Deltamethrin in Tomato Fruit and Soil.

Tomato, Lycopersicon esculentum L. is grown widely as an important day-to-day demand vegetable. The crop is attacked by various polyphagous insect pests like tomato fruit borer, stink bug, cabbage looper, flea beetle, aphids, whitefly, two-spotted spider mite, etc., and oligophagous insects like leaf-miner, five-spotted hawkmoth, etc. To combat the damage and yield loss, various chemical insecticides were sprayed on tomatoes under field conditions. The residual pattern of insecticides like chlorantraniliprole, thiamethoxam, flubendiamide, and deltamethrin residues was studied following applications of chlorantraniliprole 18.5% SC (Coragen) @ 30 g a.i./ha, thiamethoxam 25% WG (Actara) @ 50 g a.i./ha, flubendiamide 39.35 M/M SC (Fame) @ 48 g a.i./ha and deltamethrin 2.8% EC (Decis 100) @ 12.5 g a.i./ha using Reverse Phase High-Performance Liquid Chromatography (RP-HPLC). Fruit samples were collected at 0 (1 h after application), 1, 2, 3, 5, 7 days and at harvest time. All the residues of insecticides such as chlorantraniliprole (0.09 mg kg- 1), thiamethoxam (0.03 mg kg- 1), flubendiamide (0.02 mg kg- 1), and deltamethrin (0.01 mg kg- 1) were persisted up to 5th day. There were no residues found at harvest time. The residues of chlorantraniliprole and deltamethrin persisted up to 3rd day of spraying whereas the residues of flubendiamide and thiamethoxam were not detected on the same day in the soil.

Differences in radiopacity among CT contrast agents and concentrations: A quantitative study.

BACKGROUND AND PURPOSE: Several studies in the literature have attempted to subjectively assess the degree of visualization of different neurovascular structures using different contrast agents and concentrations. Given the recent contrast shortages, we aim to objectively compare the radiopacity achieved with four angiographic contrast agents used in clinical practice. METHODS: Isovue 370, Visipaque 320, Omnipaque 300, and Isovue 300 were each drawn up at 25%, 50%, 75%, and 100% concentrations and compared against normal saline and air syringes. CT scans were obtained, and regions of interest were analyzed for radiopacity using Hounsfield unit (HU) measurements. An aneurysm model with different contrast concentrations was also scanned and dimensions compared. Two-tailed t-tests and Cohen's d coefficients were applied to assess for differences in mean HU measurements. RESULTS: Isovue 370 and Isovue 300 had the highest and lowest mean HU, respectively (p < .001). Visipaque 320 at 25% concentration had the lowest mean HU at -.76. Statistically similar agents (p < .05) were Visipaque 320 and Omnipaque 300 at a 100% concentration (p = .30), and Omnipaque 300 and Isovue 300 at a 25% concentration (p = .73). Aneurysm dimensions among Isovue 370, Visipaque 320, and Omnipaque 300 were all similar, whereas with Isovue 300, the dimensions were significantly smaller (p < .05). CONCLUSION: Isovue 370 provides the highest HU radiopacity and the most accurate aneurysm measurements. Angiographic measurements obtained with Isovue 300 may underestimate the actual aneurysmal dimensions. Visipaque 320 and Omnipaque 300 at 100% concentration have similar mean HUs and are beneficial for patients with chronic kidney or cardiac disease.

Emerging Subspecialties in Neurology: Interventional Neurology: A Starter Guide for Neurology Residents.

Interventional neurology is a subspecialty at the cross-section of neurology, neurosurgery, and neuroradiology that uses image-guided endovascular catheter techniques to diagnose and treat neurovascular disorders. Although interventional neurology techniques have existed for decades, recent landmark trials in stroke thrombectomy have catalyzed dramatic changes to the interventional neurology field, and there is rising neurology interest and representation. Unlike other neurology subspecialties, however, interventional neurology training and fellowship applications are not standardized. Thus, it can be difficult for neurology trainees to navigate this rapidly changing and multidisciplinary field. This article seeks to provide neurology residents and residency program directors with a brief overview of the modern interventional neurology field, the current fellowship application process, and tips on how neurologists can best prepare for a career in interventional neurology. To this end, we conducted a nationwide survey of interventional neurology fellowship program directors regarding training neurologists. We distill survey responses into concrete, actionable items for neurology trainees.

Evaluation of Deoxyribonucleic Acid Damage Using Neutral Comet Assay for High Radiation Doses: A Feasibility Study.

Purpose: This study aims to investigate the use of the neutral comet assay to assess deoxyribonucleic acid (DNA) damage in lymphocytes exposed to high doses of radiation. Materials and Methods: The research was conducted by obtaining informed consent, after which blood samples were taken from seven healthy individuals and this study was approved by the institutional ethics committee. At first, for the determination of dose-effect curves, samples obtained from the first five individuals were irradiated for doses ranging from 0 to 35 Gy after which they were processed under neutral comet assay. In order to verify the determined dose-effect curves, a test dose of 15 Gy was delivered to the samples obtained from the sixth and seventh individuals. The amount of DNA damage from the obtained comet assay images was analyzed using four comet assay parameters namely % tail DNA, tail length, tail moment (TM), and Olive TM (OTM). The most suitable comet assay parameter was evaluated based on the obtained dose-effect curves. Furthermore, the distribution of individual cells for each dose point was evaluated for all the four comet assay parameters to find the optimal parameter. Results: From our results, it was found that from 0 to 25 Gy all the four comet assay parameters fit well into a linear quadratic curve and above 25 Gy saturation was observed. Based on the individual cell distribution data, it was found that % tail DNA could be an optimal choice to evaluate DNA damage while using neutral comet assay for high-dose ionizing radiation. Conclusion: The neutral comet assay could be a potential tool to assess DNA damage from high doses of ionizing radiation greater than 5 Gy.

Identifying and addressing common contributors to nonadherence with ophthalmic medical therapy.

PURPOSE OF REVIEW: To discuss common reasons for nonadherence and review existing and emerging options to reduce nonadherence with ocular medical therapy and optimize therapeutic outcomes. RECENT FINDINGS: Nonadherence can arise from patient-related issues (e.g. physical, cognitive) and healthcare-related issues (e.g. cost, access to care). Multiple strategies have been developed and evaluated to overcome these barriers to adherence. Identifying nonadherence and its cause(s) facilitates the development of strategies to overcome it. SUMMARY: Many common causes of nonadherence can be mitigated through a variety of strategies presented.

A novel anti-lipopolysaccharide factor from blue swimmer crab Portunus pelagicus and its cytotoxic effect on the prokaryotic expression host, E. coli on heterologous expression.

BACKGROUND: Invertebrates like crabs employ their own immune systems to fight against a number of invasive infections. Anti-lipopolysaccharide factors (ALFs) are an important class of antimicrobial peptides (AMPs) exhibiting binding and neutralizing activities against lipopolysaccharides. RESULTS: This study identified and characterized a novel homolog of ALF (Pp-ALF) from the blue swimmer crab Portunus pelagicus. Pp-ALF has a 369bp open-reading frame encoding a protein with 123 amino acids. The deduced protein featured an LPS-binding domain and a signal peptide. The predicted tertiary structure of Pp-ALF contains three α helices packed against four ß sheets. The deduced amino acid sequence of Pp-ALF had a net positive charge of +10.75 and an isoelectric point of 9.8. Phylogenetic analysis revealed that Pp-ALF has a strong ancestral relationship with crab ALFs. CONCLUSION: Antibacterial, antiviral, antifungal, anticancer, and antibiofilm activities of Pp-ALF could be revealed by in silico prediction tools. Recombinant expression of Pp-ALF was unsuccessful in the Escherichia coli Rosetta-gami expression system due to the cytotoxic effect of the peptide to the host. The toxic effect of Pp-ALF to the host was displayed by membrane permeabilization and death of the host cells by fluorescent staining with Syto9-Propidium Iodide and CTC-DAPI- FITC.

Procedural and Clinical Outcome Analysis of Monoplane versus Biplane Angiography Suites in Stroke Thrombectomies.

BACKGROUND: Thrombectomy is now the standard of care in the treatment of acute ischemic stroke caused by emergent large vessel occlusion. Therefore thrombectomy services have expanded from Comprehensive Stroke Centers to Thrombectomy-Capable Stroke Centers. Stroke interventions at these sites are performed in both biplane and monoplane angiography suites. It has been hypothesized that differences in these systems may affect time to successful reperfusion, with a potentially significant effect on neurologic outcomes. With an increase in TSCs, this study aims to evaluate the safety and efficacy of monoplane thrombectomy versus biplane thrombectomy. METHODS: Patients who presented with isolated proximal middle cerebral artery M1 occlusions and underwent endovascular thrombectomy from March 2015 to August 2018 at 5 different centers within a single health system were included. Thrombectomy was performed by the same group of experienced neurointerventionalists. The primary endpoint was functional outcome as measured by the modified Rankin scale at 90 days. Secondary endpoints included recanalization grade as measured by the Thrombolysis in Cerebral Infarction score, time to final reperfusion, and incidence of hemorrhagic conversion. RESULTS: A total of 197 patients were included in this study. Of them, 80.7% underwent thrombectomy on biplane systems. Time to final reperfusion was 10.2 minutes longer in the monoplane group but was not statistically significant (P = 0.252). There was no significant difference in the rates of favorable reperfusion (P = 0.755), hemorrhagic conversion (P = 0.580), or functional outcome at 90 days (favorable modified Rankin Scale 0-2, P = 0.210; favorable modified Rankin Scale 0-3, P = 0.697). CONCLUSION: Despite perceived advantages of biplane systems in reducing procedural time, our study demonstrates no significant differences between systems. These data support the safety and efficacy of performing thrombectomy on monoplane systems and may also carry implications for reducing patient transfer times and potentially increasing thrombectomy access to areas of the world where biplane suites may not be available. The next step would be a prospective randomized trial comparing both systems in different settings.

Functional characterization of a histone H2A derived antimicrobial peptide HARRIOTTIN-1 from sicklefin chimaera, Neoharriotta pinnata.

Antimicrobial peptides (AMPs) are gene encoded short peptides which play an important role in the innate immunity of almost all living organisms ranging from bacteria to mammals. Histones play a very important role in defense as precursors to bioactive peptides. The present study is an attempt to decipher the antimicrobial activity of a histone H2A derived peptide, Harriottin-1 from sicklefin chimaera, Neoharriotta pinnata. Analysis in silico predicted the molecule with potent antibacterial and anticancer property. The Harriottin-1 was recombinantly produced and the recombinant peptide rHar-1 demonstrated potent antibacterial activity at 25 µM besides anticancer activity. The study strongly suggests the importance of histone H2A derived peptides as a model for the design and synthesis of potent peptide drugs.

On Comparison of Heat Treated and Non-Heat-Treated LOM Manufactured Sample for Poly(lactic)acid: Mechanical and Morphological View Point.

This work reports the comparison of heat-treated and non-heat-treated laminated object-manufactured (LOM) 3D-printed specimens from mechanical and morphological viewpoints. The study suggests that heat treatment of the FDM-printed specimen may have a significant impact on the material characteristics of the polymer. The work has been performed at two stages for the characterization of (a) non-heat-treated samples and (b) heat-treated samples. The results for stage 1 (non-heat-treated samples) suggest that the infill density: 70%, infill pattern: honeycomb, and six number of discs in a single LOM-manufactured sample is the optimized condition with a compression strength of 42.47 MPa. The heat treatment analysis at stage 2 suggests that a high temperature: 65 °C, low time interval: 10 min, works equally well as the low temperature: 55 °C, high time interval: 30 min. The post-heat treatment near Tg (65 °C) for a time interval of 10 min improved the compressive strength by 105.42%.

On Laminated Object Manufactured FDM-Printed ABS/TPU Multimaterial Specimens: An Insight into Mechanical and Morphological Characteristics.

Fused deposition modeling (FDM) printing of commercial and reinforced filaments is a proven and well-explored method for the enhancement of mechanical properties. However, little has hitherto been reported on the multi-material components, fused or laminated together into a single specimen by using the laminated object manufacturing (LOM) technique for sustainable/renewable polymers. TPU is one such durable and flexible, sustainable material exhibiting renewable and biocompatible properties that have been explored very less often in combination with the ABS polymer matrix in a single specimen, such as the LOM specimen. The current research work presents the LOM manufacturing of 3D-printed flexural specimens of two different, widely used polymers available viz. ABS and TPU and tested as per ASTM D790 standards. The specimens were made and laminated in three layers. They were grouped into two categories, namely ABS: TPU: ABS (ATA) and TPU: ABS: TPU (TAT), which are functionally graded, sandwiched structures of polymeric material. The investigation of the flexural properties, microscopic imaging, and porosity characteristics of the specimens was made for the above categories. The results of the study suggest that ATA-based samples held larger flexural strength than TAT laminated manufactured samples. A significant improvement in the peak elongation and break elongation of the samples was achieved and has shown a 187% increase in the break elongation. Similarly, for the TAT-based specimen, flexural strength was improved significantly from approximately 6.8 MPa to 13 MPa, which represents a nearly 92% increase in the flexural strength. The morphological testing using Tool Maker's microscopic analysis and porosity analysis has supported the observed trends of mechanical behavior of ATA and TAT samples.