Poly Methyl Methacrylate Research Articles

Application of MATLAB and SAS Viya AI models towards the elucidation of potential microplastics in the Neuse River Basin

Microplastics (MPLs) are ubiquitous particles derived from degradation from plastic refuse or directly from anthropogenic sources. These particles are present in aquatic environments with potential toxicology across the biosphere. In order to characterize their presence, the Neuse River basin was selected for sampling. However, like many MPLs, spectroscopic characterization can be sullied by weathering processes that obscure the native spectra. Therefore, to enhance MPL identification, Principal Component Analysis (PCA), K-means Clustering (KMC), MATLAB, and SAS Viya’s machine learning (ML) modules were implemented on the Neuse River basin's samples. 18 unknown samples were recorded with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy against the controls for PCA and KMC: high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and nylon-6 (PA6). Later on, these unknowns were tested against a new set of 900 commercial control samples partitioned by 9 classes for MATLAB and SAS Viya: cellulose acetate (CA), HDPE, LDPE, PP, PS, PVC, PET, polymethyl(methacrylate) (PMMA), and PA6 using µ-FTIR (micro-FTIR) for single-particle discrepancy. Application of MATLAB’s Classification Learner and SAS Viya for Learners software helped aggregate multiple machine learning (ML) models to test for corroboration of predictions with datasets derived from Version 1 (V1), Version 2 (V2), and Version 3 (V3) feature extraction algorithms. Novel feature extractions, based on regressions of discrete data from spectral intensities, in V2 and unique probing of the relationships informing the regressions in V3 showed moderate to moderately high predictor strength, contributing to accuracy increase in V3 according to various predictor strength algorithms in MATLAB. In the test scenario of the strongest version, V3, 63.2% (+ 5.3% from V1) of the models performed very strongly (90% cutoff in accuracy), and 89.5% (+ 0% from V1) of the models performed moderately strongly (80% cutoff in accuracy). The models, coupled with the unsupervised PCA and KMC, indicated microparticle (MP) from Stockinghead Creek in Duplin County, NC; SHR-1b(2), as LDPE. However, the change in corroboration across model types was not significant, according to Kruskal-Wallis (H = 0.555, p = .7577). An ANOVA was performed to see if LDPE incidence was similar across all unknowns, indicating a similar ratio of predictions, excluding NRCP-1 (F = 31.479, p < .0001). While it is unclear if this particle is truly LDPE, the results may suggest that LDPE could be of high presence in the river basin (specifically, PE) when taking into account the predictor set across all versions. Lastly, misclassification was further elucidated for samples “CF-3” and “NRCP-1(2)” which are thought to be extensively-degraded PVC MPLs.

Flexible and Compact PVDF/PMMA-Based Gel Polymer Electrolytes for High-Performance Sodium Metal Batteries.

Sodium is gaining recognition as a promising alternative to lithium for battery applications, particularly in sodium metal batteries (SMBs), where the performance is critically influenced by the choice of electrolyte. Although conventional organic liquid electrolytes are widely used, they pose significant issues. Gel membrane (GM)-based electrolytes have demonstrated enhanced reliability and stability. Nevertheless, there remains a pressing need to improve their electrochemical and mechanical properties to fulfill the demands of next-generation batteries, which require extended lifespan, rapid charging capabilities, and excellent flexibility. To address these challenges, a compact and flexible GM is developed by gelating a cast Polyvinylidene fluoride (PVDF)/Polymethyl methacrylate (PMMA) blend film. The resulting GM possesses a suitable sodium ionic conductivity of 0.507 mS cm-1 and an impressive ion transference number of 0.47, enabling dendrite-free reversible sodium plating and stripping for up to 300 h at a current density of 0.8 mA cm-2. Furthermore, the effectiveness of sodium dendrite suppression is demonstrated in Na/GM/Na3V2(PO4)3 cells, which exhibit a high discharge capacity and excellent cycling stability. The flexible SMB retains stable voltage output and continues to function even when bent or twisted. This study introduces a novel strategy for creating gel electrolytes for high-performance flexible SMBs.

Evaluation of Microplastics Ingested by Sea Cucumber Holothuria Scabra from Pulau Jambongan, Sabah.

Microplastics (MPs) are tiny plastic pieces having a diameter of less than 5mm. They can arise from larger plastic debris that degrades over time, synthetic fibres from clothing, microbeads in personal care items and even larger plastic debris. Sea cucumbers are marine creatures vital to the ocean's ecosystem as they assist in maintaining a clean seabed and recycle nutrients. The aim of this research was to characterize the types of MPs isolated from the sea cucumber Holothuria scabra from Pulau Jambongan, Sabah. A total of 30 H. scabra were collected. Their gastrointestinal tracts were removed and digested using NaOH. The digestates were filtrated several times to extract the MPs. MPs were observed under microscope and categorized into shapes and colours. To determine the functional group of polymers, further analysis using Fourier Transform-Infrared Spectroscopy (FTIR) was performed. The samples contained a total of 7403 MPs. Majority of MPs were black colored (72.25%) and in the form of fibres (99.05%). Two types of polymers were detected: polycarbonate (PC) found in 4% of the population and polymethyl methacrylate (PMMA) present in 96%. In conclusion, the presence of MPs in the gastrointestinal tract of H. scabra suggests that the animals and their habitat have been contaminated. Further study is required to comprehend the effects of MPs on sea cucumbers and other marine organisms as well as to develop prevention strategies.

Preparation of polymer hollow microsphere filled epoxy resin-based syntactic foam material and its performance analysis

To explore sound-absorbing and flame-retardant materials that meet the requirements for double-shielded and double-insulated Faraday cages, polymethyl methacrylate (PMMA) microspheres were incorporated into epoxy resin-based syntactic foam materials for testing and analysis. The addition of PMMA microspheres was found to enhance the electrical, mechanical, sound-absorbing, and flame-retardant properties of the syntactic foam, providing a potential reference for applications in high-voltage hall shielding and sound absorption. Syntactic foams with four concentrations of PMMA microspheres (0%, 0.5%, 1%, and 2%) were prepared. High-voltage breakdown testing, impedance tube testing for sound absorption coefficient, cone calorimetry for flame-retardant performance, and tensile and bending tests were conducted. Results showed that as the concentration of PMMA microspheres increased, improvements were observed in the tensile, bending, flame-retardant, and sound absorption properties of the syntactic foams, while breakdown strength decreased. These findings provide valuable insights into the application of syntactic foam materials in double-insulation, double-shielded Faraday cages.

AI-driven data fusion modeling for enhanced prediction of mixed-mode I/III fracture toughness

This research evaluates the use of artificial intelligence to enhance the accuracy of predictions for mixed-mode I/III fracture toughness in polymethyl methacrylate . Traditionally, assessing fracture toughness relies heavily on destructive testing methods, specifically using edge-notch disc bend specimens subjected to three-point bending tests. These established methods are not only expensive and time-consuming but also frequently limited by the availability of data. To address these challenges, this study introduces a data fusion source modeling approach. This approach integrates primary fracture toughness test data with secondary predictive data derived from the maximum tangential stress criterion and the local strain energy density criterion. By employing adaptive boosting and general regression neural network algorithms, the models developed in this research demonstrate a marked improvement in predictive performance compared to traditional primary source models. Additionally, a feature importance analysis using Shapley Additive exPlanations values reveals that the mode mixity parameter, specimen thickness, and radius are critical factors influencing fracture toughness. The study highlights that while mode mixity emerges as the most significant factor, a reduction in specimen thickness generally leads to decreased fracture toughness, whereas an increase in radius has a more complex, often negative, effect. The results of this study indicate that AI-powered models using data fusion can overcome limitations related to data scarcity, enabling more accurate predictions in fracture mechanics. Furthermore, this approach provides a pathway for utilizing AI in other engineering domains where data sets are limited.

Keratoprosthesis of Brazil (KoBra): Preliminary Results of the First 2 Human Cases

Purpose: We evaluated the clinical performance of a novel keratoprosthesis (KPro) named KoBra (Keratoprosthesis of Brazil) in patients with corneal blindness. Methods: Two-piece KPro was three-dimensionally (3D) printed using titanium alloy powder (Ti-6Al-4V) and polymethyl methacrylate (PMMA). The KPros were implanted unilaterally in 2 patients who had corneal disease that was not amenable to standard corneal transplantation. An autologous full-thickness corneal graft was used as the KPro carrier. Patients were examined for at least 16 months to evaluate retention and postoperative complications. Biomicroscopy and anterior segment optical coherence tomography (AS-OCT) were performed throughout the experiment to evaluate the relationship between the KPro and the carrier graft. Results: No intraoperative complications occurred during the surgeries, and the immediate postoperative period was uneventful. The implanted KoBra integrated well into all operated eyes, and clear optics without prothesis extrusion were maintained. The mean duration of the postoperative follow-up was 17 months (range 16–18 months). AS-OCT demonstrated the correct relationship of the device and carrier at the final follow-up in all cases. Conclusions: The first short-term clinical analysis demonstrated good outcomes associated with this new technology in 2 patients who were not amenable to standard corneal transplantation. Longer follow-up and additional implantations are necessary to better assess the safety and efficacy of this device.

Mechanical, permeability, and optical properties of concrete integrating light-transmitting materials with high contents and large diameters

ABSTRACT The present study focuses on developing LTC panels with high light transmission efficiency by integrating optical fibers or Polymethyl Methacrylate (PMMA) rods at volumes of 10–30% into the concrete. This aims to enhance the percentage of light intensity transmitted through the LTC to approximately 30% from the light source, a significant improvement compared to most previous studies where it was below 10%. Various configurations of these materials, differing in diameter and volume, were tested for their effects on mechanical strength, permeability, and optical properties. Unlike most previous studies using optical fibers smaller than 2.0 mm, the findings indicate that using optical fibers or PMMA rods with larger diameters improves the feasibility of casting LTC panels with ultra-high light transmission capacity and compressive strength above 40 MPa. The mechanical strength of LTC samples can be predicted based on the effective cross-section, excluding the area occupied by light-transmitting materials. The study also reveals that larger PMMA rods increase permeability due to weaker bonds with the surrounding concrete. Additionally, LTC panels can transmit colors and images without altering the original light source color, highlighting LTC’s potential for creative applications, such as smart traffic signal displays on pavements or unique architectural designs.

Antibiotic Release and Mechanical Performance of Polymethylmethacrylate (PMMA) Bone Cement: Findings from In-vitro Studies

Using Polymethylmethacrylate (PMMA) bone cement is widespread in orthopedic surgeries for implant fixation and as a carrier for antibiotic delivery to prevent and treat infections. This review comprehensively evaluates in-vitro studies investigating the antibiotic elution profiles and mechanical properties of PMMA bone cement. We explore the kinetics of antibiotic release, factors influencing elution efficiency and the impact of various antibiotics on the mechanical properties of PMMA composites. At the same time, we examine how the inclusion of antibiotics affects the mechanical integrity of PMMA, including parameters such as compressive strength, tensile strength and fatigue resistance. Through a detailed analysis of these studies, this review aims to provide insights into optimizing PMMA bone cement formulations for enhanced therapeutic efficacy and structural performance. Using Polymethylmethacrylate (PMMA) bone cement is widespread in orthopedic surgeries for implant fixation and as a carrier for antibiotic delivery to prevent and treat infections. This review comprehensively evaluates in-vitro studies investigating the antibiotic elution profiles and mechanical properties of PMMA bone cement. We explore the kinetics of antibiotic release, factors influencing elution efficiency and the impact of various antibiotics on the mechanical properties of PMMA composites. At the same time, we examine how the inclusion of antibiotics affects the mechanical integrity of PMMA, including parameters such as compressive strength, tensile strength and fatigue resistance. Through a detailed analysis of these studies, this review aims to provide insights into optimizing PMMA bone cement formulations for enhanced therapeutic efficacy and structural performance.

Stepwise Construction of Supramolecular A2B4-Type Miktoarm Star Copolymers with a Cobalt Phthalocyanine Core.

Supramolecular interactions between polymers play a crucial role in the construction of three-dimensional polymer structures with unique physical and chemical properties. In this study, we have fabricated a novel supramolecular miktoarm star copolymer (μ-star) with a cobalt(II) phthalocyanine (CoPc) core using metal-ligand coordination. Axial coordination of the terminal pyridyl group of poly(methyl methacrylate) with the CoPc core of four-armed star-shaped polystyrene provided AB4- and A2B4-type μ-stars through stepwise complexation. The spin-coated polymer films from mixed solutions of CoPcPS4 and pyPMMA in 1 : 1 or 1 : 2 mass ratios exhibited phase-separated nanodomains with smooth surfaces. Supramolecular interactions in polymer systems provide a unique topology to polymers and affect their bulk morphology.

Evaluating the Flexural Strength and Charpy Impact Strength Of CAD/CAM And Compressed Molded PMMA Dentures: An In Vitro Study

PMMA (Polymethyl methacrylate) is a wide range of polymers are commonly used for various applications in prosthodontics. And the embedding of tooth specimens for research purposes. The unique properties of PMMA, such as its low density, aesthetics, cost-effectiveness, ease of manipulation, and tailorable physical and mechanical properties, make it a suitable and popular biomaterial for these dental applications. These complete dentures can be manufactured using two techniques: (i) conventional compression molding (CCM) technique and (ii) CAD/CAM technology. The objective of this study was to evaluate the mechanical properties of CAD/CAM PMMA denture compared to compressed molded PMMA, manufactured using the CCM technique and CAD/CAM technology. The study consisted of twenty samples, divided into two groups based on their manufacturing technique (conventional and CAD/CAM), with five samples assigned to each test. The mechanical properties of the samples were tested using flexural strength, and Charpy impact strength tests after immersing the samples in artificial saliva at 37°C for one week. The results showed that using different manufacturing techniques for PMMA CDs leads to differences in measured characteristics that affect their suitability as the only available treatment for edentulous patients. However, a statistical analysis using SSPS tools showed that the differences are not significant between the CCM technique and CAD/CAM technology. Despite the lack of statistical significance, The PMMA CDs manufactured using the CAD/CAM technology route are recommended due to their better mechanical resistance properties.

Understanding the influence of configurations and intermolecular interaction on thermomechanical and dynamics properties of polymer–clay nanocomposites via molecular dynamics simulations

AbstractPolymer‐clay nanocomposites (PCNs) have emerged as highly versatile structural materials that possess exceptional thermomechanical and dynamic properties, all the while retaining their inherent attributes of being lightweight and optically clear. The fabrication of nanocomposites involves the incorporation of carefully calibrated quantities of clay nanofillers into polymer matrixes. Current research expands upon existing coarse‐grained (CG) models of nanoclay and poly (methyl methacrylate) (PMMA) and utilize molecular dynamics simulations to methodically explore the thermomechanical characteristics of PCNs. Specifically, the effects of exfoliated and stacked configurations of nanoclays, as well as variations in intermolecular interactions between the nanoclay and polymer constituents were tested. Tensile and shear simulations, as well as interfacial behaviors, are conducted. The intermolecular interaction could have significant influences on Shear Modulus and Young's Modulus, and those influences have their characteristics due to different configurations and different force directions, such as in most cases, exfoliated structures exhibit higher mechanical modulus compared with stacked configurations at varying interaction strengths. Additionally, in the in‐plane direction, they demonstrate stronger resistance effects compared with the out‐of‐plane direction. The interaction between PMMA and nanoclay slows down the global dynamics of PMMA, with a stronger effect observed for higher interaction strength. The impact of nanoclay on the segmental dynamics of PMMA decreases as we move away from the nanoclay layers toward the pure PMMA matrix. These findings provide molecular insights into the arrangement of components in PCNs during deformation and highlight the significance of nanoclay and the interface in determining their mechanical and dynamic properties.Highlights Variation patterns of mechanical modulus with interactions and configurations. The property difference in mechanical modulus due to configurations. Positive correlation between polymer Tg and intermolecular interaction. Global and local confinement effects on molecular stiffness during tension. Dynamical heterogeneity behavior on different interactions and temperatures.

Survival and Success of 3D-Printed Versus Milled Immediate Provisional Full-Arch Restorations: ARetrospective Analysis.

To evaluate and compare the survival rates of 3D-printed and chairside milled resin polymethylmethacrylate (PMMA) immediate temporary provisional full-arch implant restorations using prosthetic survival as the primary outcome. Records of 335 routine patients receiving 443 temporary six-implant retained maxillary or mandibular prosthetic restorations between January 2019 and January 2022 at a private clinic (Dr Sobczak Clinical Centre, Radosc, Poland) were considered for this retrospective analysis. The analysis compared prosthetic and implant failure rates between printed and milled restorations as primary and secondary outcomes, respectively. Patient-related and treatment-related characteristics between groups were compared using the Chi-square test and Mann-Whitney U-test, respectively. Group-specific cumulative prosthetic survival was qualitatively and quantitively compared using Kaplan-Meier, generalized linear mixed models and univariate cox proportional hazard analyses. Prosthetic survival was set into context to implant survival using Chi-square tests. A multivariable cox proportional hazards model with frailty was used to identify confounding factors affecting prosthetic survival. Prosthetic failure rates of milled and printed temporary restorations were 13.01% and 11.25% over the average follow-up period of 307.7 ± 115.5 days, respectively. The corresponding 180-day cumulative prosthetic survival rates were 92.4% and 93%. Hazard ratios for the prosthetic failure of milled and printed restorations did not show a statistical difference (p = 0.794). Implant failure rates in restorations that experienced prosthetic failure (17.31%) were higher compared to restorations without failures (5.63%), with a 3.2 times significantly higher odds of failure for a prosthesis experiencing implant loss (p = 0.003). Gender, presence of teeth at treatment baseline, smoking, and bone augmentation were identified as confounding factors impacting prosthetic survival. Chairside 3D-printed restorations may represent an equivalent treatment modality to established chairside milled restorations for immediate full-arch therapy. Provisional prosthetic survival may impact implant survival and treatment success.

Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) Monolith with Dual Porosity for Size Exclusion Chromatography.

The use of polymeric monoliths as stationary phases for liquid chromatography has been limited, despite their ability to enhance the convection flow of the mobile phase with respect to particulate-based columns. This is due to a poor balance between the volume of flow through pores and the number of active sites within polymeric monoliths. In this paper, we present the obtainment of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (P(GMA-co-EDMA)) monoliths with dual pore size distributions (with pore sizes of 60 and 550 nm). Hierarchical pore size distributions were achieved by performing the monolith synthesis by reversible addition-fragmentation chain transfer (RAFT) polymerization as well as using ternary porogen mixtures (containing PEG, dodecanol, and dioxane). While the controlled polymerization mechanism promoted mesopores in the monolith, ternary porogen mixtures allowed the formation of macropores. The monoliths obtained were used as stationary phases for size exclusion chromatography (SEC) for the separation of poly(methyl methacrylate) standards with molar masses between 2.50 × 103 and 3.06 × 106 g/mol, allowing selectivities that were comparable with commercially available SEC columns packed with porous particles. We believe the approach presented in this work could be the first step toward the obtainment of stationary phases for SEC with enhanced accessibility of exclusion pores. Monolithic columns with accessible porous structures can be beneficial for size-based separations of ultrahigh molar mass analytes with low diffusion coefficients.

Silver Nanoparticles (AgNPs) Incorporation into Polymethyl Methacrylate (PMMA) for Dental Appliance Fabrication: A Systematic Review and Meta-Analysis of Mechanical Properties

Silver Nanoparticles (AgNPs) Incorporation into Polymethyl Methacrylate (PMMA) for Dental Appliance Fabrication: A Systematic Review and Meta-Analysis of Mechanical Properties

Excitonic-Vibrational Interaction at 2D Material/Organic Molecule Interfaces Studied by Time-Resolved Sum Frequency Generation

The hybrid heterostructures formed between two-dimensional (2D) materials and organic molecules have gained great interest for their potential applications in advanced photonic and optoelectronic devices, such as solar cells and biosensors. Characterizing the interfacial structure and dynamic properties at the molecular level is essential for realizing such applications. Here, we report a time-resolved sum-frequency generation (TR-SFG) approach to investigate the hybrid structure of polymethyl methacrylate (PMMA) molecules and 2D transition metal dichalcogenides (TMDCs). By utilizing both infrared and visible light, TR-SFG can provide surface-specific information about both molecular vibrations and electronic transitions simultaneously. Our setup employed a Bragg grating for generating both a narrowband probe and an ultrafast pump pulse, along with a synchronized beam chopper and Galvo mirror combination for real-time spectral normalization, which can be readily incorporated into standard SFG setups. Applying this technique to the TMDC/PMMA interfaces yielded structural information regarding PMMA side chains and dynamic responses of both PMMA vibrational modes and TMDC excitonic transitions. We further observed a prominent enhancement effect of the PMMA vibrational SF amplitude for about 10 times upon the resonance with TMDC excitonic transition. These findings lay a foundation for further investigation into interactions at the 2D material/organic molecule interfaces.

Preparation and Characterization of Red, Green, Blue (RGB) and White Luminescent Inorganic/Organic Polymers Through In Situ Polymerization.

YVO4:Eu3+/PMMA, LaPO4:Ce3+,Tb3+/PMMA and CaWO4/PMMA nanocomposites were prepared by in situ polymerization method with hydrophobic YVO4:Eu3+, LaPO4:Ce3+,Tb3+ and CaWO4 nanoparticles as the filler and poly (methyl methacrylate) (PMMA) as the host material. All the nanoparticles and composites have been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), the thermogravimetric analysis (TGA), photoluminescence excitation, and emission spectra and luminescence decays. YVO4:Eu3+/PMMA, LaPO4:Ce3+,Tb3+/PMMA, CaWO4/PMMA nanocomposites exhibit strong red, green and blue photoluminescence upon 254nm UV excitation, respectively. The yellow and white LED nanocomposites with CIE coordinates of (0.411, 0.498) and (0.334, 0.359) were obtained by triply integrating the red, green and blue nanoparticles into PMMA. Thanks to the abundant luminescent colors from RGB to yellow and white in these polymer composites under UV excitation, they can be potentially used in various optoelectronic fields.

Synthesis of novel colored substrate-free pearlescent pigments of vanadium phosphates with large-size layered platelet morphology

Novel colored substrate-free pearlescent pigments based on vanadium phosphates, VOPO4·2H2O (VOP) and H0.6(VO)3(PO4)3(H2O)3·4H2O (HVP), with layered structures, were synthesized using solution process and hydrothermal synthesis. XRD and SAED analyses confirmed the single crystallinity of VOP and HVP. Hydrogen peroxide (H2O2) was crucial for producing larger plate-like crystal grains of VOP and contributing to the phase formation of HVP. FE-SEM analysis revealed that VOP and HVP consist of layered plate-like particles (platelets) with smooth surfaces, achieving small thicknesses and high aspect ratios (diameter to thickness). Notably, this study is the first to report particle diameters of 221 µm for VOP and 220 µm for HVP and to propose VOP and HVP as potential substrate-free pearlescent pigments. The optical properties are characterized by optical reflectance spectra and CIE L∗a∗b∗ coordinates, while the pearlescent effect was also evaluated. Under an optical microscope, all samples exhibited striking iridescent colors, visible even in different regions within the same particle. Furthermore, 1 wt% of the green HVP pearlescent pigments were successfully dispersed in the poly(methyl methacrylate) (PMMA) matrix, indicating a good suitability for PMMA colorization.

Physical Aging of Poly(methyl methacrylate) Brushes and Spin-Coated Films.

While there is significant attention aimed at understanding how one-dimensional confinement and chain confirmations can impact the glass transition temperature (Tg) of polymer films, there remains a limited focus on similar effects on sub-Tg processes, notably, structural relaxation. Using spectroscopic ellipsometry, we investigated the combined influence of confinement and molecular packing on Tg and physical aging, i.e., the property changes that accompany structural relaxation, at select film thicknesses and aging temperatures (Ta). We used poly(methyl methacrylate) (PMMA) films in the brush and spin-coated morphologies as model systems. We found that whether a PMMA film exhibited a decrease or increase in physical aging rate with confinement was dependent on the morphology. Notably, PMMA brushes exhibited higher physical aging rates compared to similarly thick spin-coated films at all values of Ta. These intriguing findings reveal the strong effects of confinement and molecular packing on the structural relaxation of polymer films. Results from this study have the potential to aid in the design of thin-film materials with controllable long-term glassy-state properties.

A digital manufactured microfluidic platform for flexible construction of 3D co-culture tumor model with spatiotemporal resolution.

The specific spatiotemporal distribution of diverse components in tumor microenvironment plays a crucial role in the cancer progression. In vitro three-dimensional(3D) tumor models with polydimethylsiloxane(PDMS) based microfluidic platform have been applied as useful tool to conduct studies from cancer biology to drug screening. However, PDMS has not been welcomed as a standardized commercial application for preclinical screening due to inherent limitations in scale-up production and molecule absorption. Here, we present a novel microfluidic platform to flexibly construct 3D co-culture models with spatiotemporal resolution by using multiple digital manufacturing(DM) technologies. The platform, which consist of reduplicative microfluidic chips, is made of biocompatible poly methyl methacrylate(PMMA) by fast laser cutting. Each replica includes a simple microfluidic chamber without internal structures which can be flexibly post-fabricated according to various research requirements. Digital light processing(DLP) based 3D bioprinting was used to pattern fine hydrogel structures for post-fabrication on-chip. By multi-step bioprinting and automatic image alignment, we showed that this approach provides sufficient design flexibility to construct 3D co-culture tumor model with spatiotemporal resolution to replicate microarchitecture of tumor microtissue in situ. And the tumor model had the potential to mimic tumor biology behaviors which could be used for mechanism study and drug test. Our microengineered tumor model may serve as an enabling tool to recapitulate pathophysiological complexity of tumor, and to systematically examine the contribution of the tumor microenvironment to the cancer progression. The proposed strategy could also be applied to help engineer diverse meaningful in vitro models for extensive biomedical applications, from physiology and disease study to therapy evaluation.

Poly (Methyl Methacrylate)/Polyaniline (PMMA/PAni) Electrospun Membranes for Use in Chemical Sensors

Poly (Methyl Methacrylate)/Polyaniline (<scp>PMMA</scp>/<scp>PAni</scp>) Electrospun Membranes for Use in Chemical Sensors