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Investigating long term storage stability and drug release behavior of polypeptide based fibrous scaffold for tissue engineering application

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materials Chemistry and Physics 2024年 321卷

作者： Chang, Chun-Yu Su, An-Jey A. Lin, Meng-Fang Hsiao, Kai-Chi Lee, Chia-Hsien Lin, Yu-Ting Hsiao, Yu-Sheng Wu, Ming-Chung Huang, Yu-Ching Su, Wei-Fang Bachelor Program in Semiconductor Materials and Fabrication Ming Chi University of Technology Taiwan Dept. of Surgery Anschutz Medical Campus University of Colorado AuroraCO United States Dept. of Materials Engineering Ming Chi University of Technology Taiwan Dept. of Chemical and Materials Engineering Chang Gung University Taiwan Dept. of Materials Science and Engineering National Taiwan University of Science and Technology Taipei City Taiwan Dept. of Materials Science and Engineering National Taiwan University Taiwan

Electrospun poly (γ-benzyl-L-glutamate) (PBG) scaffold felt with aligned fibers shows promising nerve regeneration and neurite growth capability due to the nerve stimulating moiety of glutamate in the PBG material. The nerve regeneration capability can be further enhanced by incorporating 4 wt% minocycline hydrochloride (MH) in the scaffold (PBGMH4). They are useful in the nerve tissue engineering to repair and regeneration damaged nerves in central nerve system or peripheral nerve system. Here we investigate the ambient storage capability of PBG and PBGMH4 by monitoring the changes over time of fiber dimension, mechanical properties of both scaffolds and amount of drug release of PBGMH4. It is interesting to observe the diameter of fibers and mechanical strength of scaffolds increases but the amount of drug release decrease with time. By carefully examining the top view of the scaffolds using scanning electron microscopy (SEM), the fiber diameter of PBG increased by 58 % over the 12 months storage period, which is larger than the 32 % increase observed for PBGMH4. Furthermore, after storage for 12 months, the difference in fiber diameter between the top and bottom sides of PBG scaffold is 25.9 %, whereas for PBGMH4 is only 6.3 %. These results demonstrate that the PBGMH4 scaffold exhibits superior storage stability compared to that of PBG. Because the fibers of the scaffolds are aligned without any crosslinkage, the scaffolds are porous structure of felts. The porosity of PBGMH4 scaffold is decreased from 90 % to 72 % which can be accountable for the decrease of drug release from initial 42 % to a stabilized 26 % after 9 months of storage. The results indicate the specific surface area of the scaffolds play an important role in governing drug release kinetics. This study thoroughly investigates the storage stability of PBG and PBGMH4 electrospun fibrous scaffolds. The observed correlations between fiber diameter, mechanical properties, and drug release behavior hol

关键词： Electrospinning

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Investigating Long Term Storage Stability and Drug Release Behavior of Polypeptide Based Fibrous Scaffold for Tissue engineering Application

SSRN

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SSRN 2024年

作者： Chang, Chun-Yu Su, An-Jey Lin, Meng-Fang Hsiao, Kai-Chi Lee, Chia-Hsien Lin, Yu-Ting Hsiao, Yu-Sheng Wu, Ming-Chung Huang, Yu-Ching Su, Wei-Fang Bachelor Program in Semiconductor Materials and Fabrication Ming Chi University of Technology Taiwan Dept. of Surgery Anschutz Medical Campus University of Colorado AuroraCO United States Dept. of Materials Engineering Ming Chi University of Technology Taiwan Dept. of Chemical and Materials Engineering Chang Gung University Taiwan Dept. of Materials Science and Engineering National Taiwan University of Science and Technology Taipei City Taiwan Dept. of Materials Science and Engineering National Taiwan University Taiwan

Electrospun poly (γ-benzyl-L-glutamate) (PBG) scaffold felt with aligned fibers shows promising nerve regeneration and neurite growth capability due to the nerve stimulating moiety of glutamate in the PBG material. The nerve regeneration capability can be further enhanced by incorporating minocycline hydrochloride drug in the scaffold (PBGMH). They are useful in the nerve tissue engineering to repair and regeneration damaged nerves in central nerve system or peripheral nerve system. Here we investigate the ambient storage capability of PBG and PBGMH by monitoring the changes over time of fiber dimension, mechanical properties of both scaffolds and amount of drug release of PBGMH. It is interesting to observe the diameter of fibers and mechanical strength of scaffolds increases but the amount of drug release decrease with time. By carefully examine the top view and bottom view of the 40 micron thick scaffolds by scanning electron microscopy (SEM), the increased diameter of fibers on the top of the scaffold is less than that of the bottom of the fiber. Because the fibers of the scaffold are aligned without any crosslinkage, it is a porous structure of felt, the fibers of scaffolds are settled down with gravity. The porosity of PBG scaffold is decreased from 90% to 72% which can be accountable for the decrease of drug release from initial 42% to a stabilized 26% after nine months of storage. The results indicate the specific surface area of the scaffold play an important role in governing drug release kinetics. This study thoroughly investigates the storage stability of PBG electrospun fibrous scaffold. The observed correlations between fiber diameter, mechanical properties, and drug release behavior hold implications for the design of advanced bioscaffolds. The long shelf life of optimal PBGMH4 scaffold shows potential application for the nerve regeneration and controlled drug delivery systems. © 2024, The Authors. All rights reserved.

关键词： Fibers

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Mechanisms of Mesoscale Hydride Morphology and Reorientation in a Polycrystal Investigated Using Phase-Field Modeling 20

Mechanisms of Mesoscale Hydride Morphology and Reorientation...

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20th International Symposium on Zirconium in the Nuclear Industry

作者： Simon, Pierre-Clément A. Chen, Long-Qing Daymond, Mark R. Motta, Arthur T. Tonks, Michael R. Ken and Mary Alice Lindquist Department of Nuclear Engineering The Pennsylvania State University 233 Hallowell Building University ParkPA16802 United States Computational Mechanics and Materials Department Idaho National Laboratory Idaho FallsID83415 United States Department of Materials Science and Engineering The Pennsylvania State University University ParkPA16802 United States Dept. of Mechanical and Materials Engineering Queen's University KingstonONK7L 2N8 Canada Dept. of Materials Science and Engineering University of Florida GainesvilleFL32611 United States

ISBN: (纸本)9780803177376

This study focuses on the precipitation of nanoscale hydrides in polycrystalline zirconium as a first step to predicting the hydride morphology observed experimentally and investigating the mechanisms responsible for hydride reorientation at the mesoscale. A quantitative phase-field model, which includes the elastic anisotropy of the nanoscale zirconium hydride system, is developed to investigate the mechanism of hydride reorientation in which the presence of an applied hoop stress promotes hydride precipitation in grains with basal poles aligned with the circumferential direction. Although still elongated along the basal plane of the hexagonal matrix, nanoscale hydrides growing in grains oriented perpendicular to the applied stress appear radial at the mesoscale. Thus, a preferential hydride precipitation in grains with basal poles aligned parallel to the applied stress could account for mesoscale hydride reorientation. This mechanism is consistent with experimental observations performed in other studies. Copyright © 2023 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.

关键词： Zirconium compounds

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A Multiscale Parametric Study to Drug Delivery Modeling in Stented Arteries

A Multiscale Parametric Study to Drug Delivery Modeling in S...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Dimitrios S. Pleouras Vasileios S. Loukas Georgia S. Karanasiou Anastasia Antonaki Dimitrios I. Fotiadis Antonis I. Sakellarios Dept. of Materials Science and Engineering Unit of Medical Technology and Intelligent Information Systems University of Ioannina Ioannina Greece Dept. of Materials Science and Engineering University of Ioannina Ioannina Greece Dept. of Materials Science and Engineering Unit of Medical Technology and Intelligent Information Systems University of Ioannina Biomedical Resarch Institute FORTH-IMBB Ioannina Greece Dept. of Mechanical and Aeronautics Engineering University of Patras Patras Greece

ISBN: (数字)9798350371499

ISBN: (纸本)9798350371505

The aim of this work is to investigate the dynamic behavior of retinoic acid concentration within the coronary artery, examining its distribution both on the stent and to the lumen and the arterial wall. The study aims to elucidate the effect of various factors, including variations in retinoic acid concentration on the stent, the applied blood flow velocity as boundary condition within the lumen, the polymer layer porosity, the arterial wall porosity and the drug permeability. Through a comprehensive analysis of these factors, this research seeks to advance the understanding of how retinoic acid behaves in the complex environment of the coronary artery, offering valuable insights into potential therapeutic applications and advances in cardiovascular medicine. To do this, a multiscale computational model for drug delivery is employed and applied in a stented arterial segment. 3D reconstruction of the arterial artery was achieved using optical coherence tomography (OCT) and X-ray angiography. The positioning of stent geometry was performed using finite element modeling of stent deployment. The results demonstrate that changes to important parameters of the model lead to significant changes to the drug *** Relevance: The importance of this work is related to the development and design of new coronary stents and potentially consider the patient’s phenotype and provide personalized applications.

关键词： Drugs Solid modeling Three-dimensional displays Phenotypes Lumen Drug delivery Finite element analysis Permeability Polymers Arteries

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Meso-Scale Modelling of Complex Fibre Composite Geometries Using the Finite Cell Method

SSRN

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SSRN 2024年

作者： Börjesson, Elias Verhoosel, Clemens V. Remmers, Joris J.C. Fagerström, Martin Dept. Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden Dept. Mechanical Engineering Eindhoven University of Technology Eindhoven Netherlands

This paper investigates the application of immersed methods to simplify the discretisation and modelling process for meso-scale geometries in fibre-reinforced composites. The geometry of meso-scale structures in fibre-reinforced composites can often be categorised as complex, and frequently presents considerable challenges for meshing software. This complexity necessitates either time-consuming manual intervention or the adoption of simplified discretisation approaches, such as voxel methods, which may compromise accuracy. To address this issue, we study the use of the Finite Cell Method (FCM) in combination with Isogeometric Analysis (IGA) for the discretisation of the matrix regions of the meso-scale geometry. This combination has the potential to minimises the requirement for manual intervention in the discretisation processes with little effect to the accuracy of e.g. stresses. We validate the proposed modelling framework in three numerical examples, where homogenised stiffnesses and stress levels are analysed in various fibre composite architectures. © 2024, The Authors. All rights reserved.

关键词： Geometry

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Investigation of the Effects of Oyster Shell Powder Bio-Fillers on the mechanical Properties of Reinforced Epoxy Composites

Investigation of the Effects of Oyster Shell Powder Bio-Fill...

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science, engineering and Business for Sustainable Development Goals (SEB-SDG), International Conference on

作者： Newton I. Agbeboh Abon Adus Adeolu A. Adediran Isiaka O. Oladele Oluwasogo L. Ogundipe Dept. of Mechanical and Mechatronics Engineering Federal University Otuoke Bayelsa State Nigeria Dept. of Mechanical Engineering Landmark University Omu-Aran Kwara State Nigeria Dept. of Mechanical Science University of Johannesburg South Africa Dept. of Metallurgical and Materials Engineering Federal University of Technology Akure Ondo State Nigeria

ISBN: (数字)9798350358155

ISBN: (纸本)9798350358162

Oyster shells are majorly composed of large amounts of calcium with layers of viscoelastic proteins. However, due to their biodegradability, Oyster shells are regarded as waste materials. The shells can be combined with lightweight polymer matrices, like the widely used epoxy thermosetting polymer. This research seeks to utilize oyster shells as bio-fillers for reinforced epoxy composite manufacture. Oyster shell powder was, used as a reinforcement for an epoxy polymer matrix to create a new composite with superior mechanical properties. Oyster shell powders were used as natural fillers composites were developed using different ratios of the Epoxy resin (10%, 20%, and 30%) of oyster shell powder, employing the hand layup method. This was done to improve the hardness, tensile, and impact resistance properties of the epoxy composite. As a direct result of using the oyster shell powders as reinforcement materials infused within the epoxy polymer matrix. The results were critically analyzed and it was discovered that the addition of oyster shell powders led to the enhancement of the impact resistance of the developed composites, while the hardness and tensile strengths of the composites were slightly reduced compared to the control. The developed composites could be utilized as plastic-based ceiling boards for the construction industry.

关键词： Proteins Waste materials Insulation Powders Composite materials mechanical factors Polymers

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Ultra-Low Thermal Conductivity of Laterally Arranged Nanowire Arrays Through Constriction engineering

Ultra-Low Thermal Conductivity of Laterally Arranged Nanowir...

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Moratuwa engineering Research Conference (MERCon)

作者： Pasan Henadeera Chamara Somarathna Wenusara Satheekshana Yohan Withanage Nalaka Samaraweera Dept. Mechanical Engineering University of Moratuwa Moratuwa Sri Lanka Dept. Materials Science and Engineering University of Moratuwa Moratuwa Sri Lanka

Nanostructured semiconductor materials exhibit remarkable thermal insulating properties compared to their bulk counterparts, making them highly promising for Thermo-Electric (TE) applications. This study employs computational tools to investigate the superior thermal insulating properties of Nanowire Chain (NWC) structures achieved through constriction engineering of laterally aligned nanowire arrays. Various surface and constriction modifications of NWCs are investigated to understand their impact on the thermal conductivity. The results demonstrate that the NWC structure achieves a substantial oneorder reduction in thermal conductivity compared to nanowires and nanosheets of similar dimensions. Moreover, this study evaluates the effectiveness of commonly used phonon suppression techniques, such as superlattice structures, shell alloying, and surface atom removal, in NWC configurations. The comprehensive analysis provides valuable insights into the phonon transport characteristics within different classes of NWCs, shedding light on their potential for diverse applications in the field of TE materials and thermal insulators.

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Development of an Automated Traffic Decongestion Control System

Development of an Automated Traffic Decongestion Control Sys...

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IEEE International Conference on Emerging & Sustainable Technologies for Power & ICT in a Developing Society (NIGERCON)

作者： Adedotun O. Adetunla Adeniran Afolalu Adeolu Adesoji Adediran Adjugah Uvietobore Joshua Samuel-Soma Ajibade Bamidele Segun Ilugbusi Dept. of Mechanical Engineering Science University of Johannesburg Johannesburg South Africa Dept. of Mechanical and Mechatronics Engineering Afe Babalola University Ado Ekiti Nigeria Department of Materials and Metallurgical Engineering Federal University of Oye-Ekiti Nigeria Department of Mechanical Engineering Science University of Johannesburg South Africa Dept. of Mechanical & Mechatronics Engineering Afe Babalola University Ado Nigeria Dept. of Computing and Information Systeems Sunway University Petaling Jaya Malaysia Dept. of Business Administration Afe Babalola University Ado Nigeria

ISBN: (数字)9798331542559

ISBN: (纸本)9798331542566

Traffic congestion in urban and rural areas causes delays, safety hazards, and pollution. This study developed a traffic decongestion system using Arduino microcontroller, IR sensors, a servomotor, and an LCD display to reduce travel time, enhance safety, and support sustainable transportation. The system detects vehicles with IR sensors, controls barriers with a servomotor, and shows lane travel times on the LCD. By installing new traffic signals and using active traffic management strategies, the system was assessed through metrics like traffic flow and pedestrian safety. Results showed that the system effectively reduced travel times, improved safety, and supported sustainable transportation. Challenges were managed through thorough testing and communication. The study’s findings validate the effectiveness of such systems and offer insights for future traffic management research and practice.

关键词： Microcontrollers Urban areas Transportation Control systems Sensor systems Liquid crystal displays Sensors Servomotors Traffic congestion Testing

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Electro-mechanical Behavior of Hybrid Composite Sandwich Radome: A-Type Radome

Electro-Mechanical Behavior of Hybrid Composite Sandwich Rad...

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International Bhurban Conference on Applied sciences & Technology, IBCAST

作者： Zhaib Muneer Ahmed Muhammad Ali Nasir Zafar Iqbal Muhammad Talha Aamir Dept. of Mechanical Engineering University of Engineering & Technology (UET) Taxila Pakistan Dept. of Surface & Materials Engineering (SCME) National University of Science & Technology (NUST) Islamabad Pakistan

ISBN: (数字)9798350308259

ISBN: (纸本)9798350308266

Today, Sandwich composite radomes are being used in fighter aircrafts, drones, UAV's and missiles. Generally radome structure can be monolayer, two layer, three layer (A-Type) and five layer (C-Type). For current study, a multidisciplinary design process for manufacturing hybrid sandwich composite A-type radomes is presented. The methodology is composed of two parallel setups for testing of electromagnetic behavior and mechanical properties of selected materials, which are simultaneously essential for the better performance of radome. The design process begins with the choice of an appropriate material to satisfy the service requirements, such as EMI transparency and structural integrity against aerodynamic loads. To choose the appropriate material and core foam, the Multi Criteria Decision Making (MCDM) method was also used. The MCDM assigns ranking to the materials to be chosen in order to satisfy functional requirements. Accordingly full scale nose radome of a flight vehicle (<0.8 Mach) was manufactured utilizing hand-layup technique assisted by vacuum bagging using SGlass/PMI Foam/Kevl $a$ and low viscosity epoxy. The full scale radome was tested to check EMI behavior (X-band frequencies) by free space measurement method. EMI response was found satisfying the requirements (as per MIL R-7705B) Furthermore, to ensure that selected materials and layup sequence will fulfil structural performance requirements of Radome, multiple specimens were prepared adhering same stacking sequence as that of the Radome. mechanical testing of specimens was carried out in accordance of ASTM Standard for flexure and tensile testing (ASTM D7246/D760 and ASTM D3039, respectively). Tensile strength of S-Glass and Kevlar was found 263 MPa and 335 MPa respectively, and flexural strength was 351 MPa and 336 MPa, respectively. The flexural testing was also done of sandwich samples comprises, as per ASTM D7246, of S-glass / Foam / Kevlar in accordance 3x ply/4mm/3x ply and 200 gsm in weig

关键词： Viscosity Antenna measurements Electromagnetic interference Vacuum technology Bending Extraterrestrial measurements Radomes MCDM Electromagnetics Testing

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Distributionally Robust Clustered Federated Learning: A Case Study in Healthcare

arXiv

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arXiv 2024年

作者： Konti, Xenia Riess, Hans Giannopoulos, Manos Shen, Yi Pencina, Michael J. Economou-Zavlanos, Nicoleta J. Zavlanos, Michael M. Dept. of Computer Science Duke University United States Dept. of Electrical and Computer Engineering Duke University United States Dept. of Mechanical Engineering & Materials Science Duke University United States School of Medicine Duke University United States

In this paper, we address the challenge of heterogeneous data distributions in cross-silo federated learning by introducing a novel algorithm, which we term Cross-silo Robust Clustered Federated Learning (CS-RCFL). Our approach leverages the Wasserstein distance to construct ambiguity sets around each client's empirical distribution that capture possible distribution shifts in the local data, enabling evaluation of worst-case model performance. We then propose a model-agnostic integer fractional program to determine the optimal distributionally robust clustering of clients into coalitions so that possible biases in the local models caused by statistically heterogeneous client datasets are avoided, and analyze our method for linear and logistic regression models. Finally, we discuss a federated learning protocol that ensures the privacy of client distributions, a critical consideration, for instance, when clients are healthcare institutions. We evaluate our algorithm on synthetic and real-world healthcare data. Copyright © 2024, The Authors. All rights reserved.

关键词： Federated learning

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