Biomedical Engineering Research Articles

Magnetic Nanoparticles in Biopolymer Fibers: Fabrication Techniques and Characterization Methods.

Hybrid nanocomposites combining biopolymer fibers incorporated with nanoparticles (NPs) have received increasing attention due to their remarkable characteristics. Inorganic NPs are typically chosen for their properties, such as magnetism and thermal or electrical conductivity, for example. Meanwhile, the biopolymer fiber component is a backbone, and could act as a support structure for the NPs. This shift towards biopolymers over traditional synthetic polymers is motivated by their sustainability, compatibility with biological systems, non-toxic nature, and natural decomposition. This study employed the solution blow spinning (SBS) method to obtain a nanocomposite comprising poly(vinyl pyrrolidone), PVA, and gelatin biodegradable polymer fibers incorporated with magnetic iron oxide nanoparticles coated with poly(acrylic acid), PAA2k, coded as γ-Fe2O3-NPs-PAA2k. The fiber production process entailed a preliminary investigation to determine suitable solvents, polymer concentrations, and spinning parameters. γ-Fe2O3-NPs were synthesized via chemical co-precipitation as maghemite and coated with PAA2k through the precipitation-redispersion protocol in order to prepare γ-Fe2O3-NPs-PAA2k. Biopolymeric fibers containing coated NPs with sub-micrometer diameters were obtained, with NP concentrations ranging from 1.0 to 1.7% wt. The synthesized NPs underwent characterization via dynamic light scattering, zeta potential analysis, and infrared spectroscopy, while the biopolymer fibers were characterized through scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis. Overall, this study demonstrates the successful implementation of SBS for producing biopolymeric fibers incorporating iron oxide NPs, where the amalgamation of materials demonstrated superior thermal behavior to the plain polymers. The thorough characterization of the NPs and fibers provided valuable insights into their properties, paving the way for their potential applications in various fields such as biomedical engineering, environmental remediation, and functional materials.

Mechanistic understanding of enhancing bioactivity via bio-ionic liquid functionalization of biomaterials

The selection of biomaterials is a pivotal criterion for designing tissue engineering scaffolds, crucial for diverse biomedical applications. While natural biomaterials offer inherent bioactivity and biocompatibility, fine-tuning their properties for specific applications poses challenges. Conversely, synthetic biomaterials, while highly customizable, are often bio-inert. Functionalizing materials with bioactive molecules can improve cell-material interactions. Prevailing approaches utilizing RGD peptides or natural/synthetic composites have drawbacks including cost and immunogenicity. Bio-ionic liquids (BILs), a class of biocompatible ionic liquids derived from natural or synthetic biomolecules, offer a potential alternative. Herein, we present the biofunctionalization of a bio-inert polyethylene glycol diacrylate (PEGDA) with an acrylated choline-based BIL (“BioPEG”) as a method for enhancing the bioactivity of biomaterials. Cell studies using mouse myoblast C2C12 and human mesenchymal stem cells (hMSCs) revealed the excellence of BioPEG hydrogels in promoting cell attachment, growth, proliferation, and differentiation. Computational molecular dynamics (MD) simulations elucidated the mechanism by which BIL facilitates cell interaction with PEGDA. 3D printability of BioPEG hydrogel was showcased using a digital light processing (DLP) bioprinter, with printed scaffolds demonstrating excellent cytocompatibility. Collectively, these findings present BIL as a versatile bioactive agent for augmenting cell adhesion to materials, thus enriching the repertoire of biomaterials for advanced tissue engineering.

Influence of slip conditions and applied magnetic field on peristaltic propulsion of ellis fluid flow in a homogeneous conduit: a parametric analysis

The peristaltic mechanism has recently garnered significant attention in biological and biomedical engineering fields. This study investigates the magnetohydrodynamic (MHD) peristaltic propulsion of an Ellis fluid through a uniform channel, incorporating slip boundary conditions. Both magnetic field presence and slip effects modulate the peristaltic motion, with various factors influencing the sinusoidal waves along the channel walls. Through appropriate assumptions and simplifications, we derive governing equations for the flow and magnetic field. The resulting nonlinear system of differential equations is solved using a perturbation technique. We thoroughly examine three key metrics: velocity, pressure gradient, and streamlines. Findings indicate that magnetic field presence and slip conditions significantly impact flow behaviour. Slip coefficients positively influence velocity and pressure difference, while the magnetic field tends to decelerate the velocity profile. A comparative analysis between Newtonian and non-Newtonian models reveals notable differences in velocity profiles. These insights have potential applications across a wide spectrum of industrial and biological contexts. This study contributes to the understanding of complex fluid dynamics in peristaltic systems, offering valuable perspectives for both theoretical advancement and practical applications in biomedical and industrial fields.

Application of a Prediction Problem-Based Learning (PPBL) Method in an Undergraduate Biomechanics Course

Abstract Challenge As biomedical engineers revolutionize medicine, biomedical engineering programs must adapt to the diverse learning styles of the current student population. Students are learning in new ways and instructional strategies need to be adopted. Novel Initiative Understanding generational attributes is crucial for developing effective teaching pedagogy. Generation Z, also known as “zoomers” and “digital natives,” will dominate higher education for the next decade. In response to the shift of how students are learning, a new teaching method called Prediction Problem-Based Learning (PPBL) was implemented in an undergraduate Biomechanics course. PPBL combines the retrieval of information with problem-based learning to enhance student engagement and active learning. Reflection Comparing this method to traditional teaching approaches demonstrated significant improvements in a course learning outcome and exam performances among students exposed to PPBL. These results suggest that PPBL fosters a deeper understanding of the material and promotes a more effective learning strategy. Further analysis and testing of this method are recommended to confirm its efficacy and explore its potential for broader application in biomedical engineering educational courses. This innovative approach aligns with the needs of Generation Z learners, who thrive in interactive and technology-enhanced educational environments, thereby providing greater opportunities for academic success and professional preparedness.

Nanogels in Biomedical Engineering: Revolutionizing Drug Delivery, Tissue Engineering, and Bioimaging

ABSTRACTNanogels represent a significant innovation in the fields of nanotechnology and biomedical engineering, combining the properties of hydrogels and nanoparticles to create versatile platforms for drug delivery, tissue engineering, bioimaging, and other biomedical applications. These nanoscale hydrogels, typically ranging from 10 to 1000 nm, possess unique characteristics such as high water content, biocompatibility, and the ability to encapsulate both hydrophilic and hydrophobic molecules. The review explores the synthesis, structural configurations, and stimuli‐responsive nature of nanogels, highlighting their adaptability for targeted drug delivery, including across challenging barriers like the blood–brain barrier. Furthermore, the paper delves into the biomedical applications of nanogels, particularly in drug delivery systems, tissue engineering, and bioimaging, demonstrating their potential to revolutionize these fields. Despite the promising preclinical results, challenges remain in translating these technologies into clinical practice, including issues related to stability, scalability, and regulatory approval. The review concludes by discussing future perspectives, emphasizing the need for further research to optimize the properties and applications of nanogels, ultimately aiming to enhance their efficacy and safety in clinical settings.

An open-source toolbox for enhancing the assessment of muscle activation patterns during cyclical movements

Objective.The accurate temporal analysis of muscle activations is of great importance in several research areas spanning from the assessment of altered muscle activation patterns in orthopaedic and neurological patients to the monitoring of their motor rehabilitation. Several studies have highlighted the challenge of understanding and interpreting muscle activation patterns due to the high cycle-by-cycle variability of the sEMG data. This makes it difficult to interpret results and to use sEMG signals in clinical practice. To overcome this limitation, this study aims at presenting a toolbox to help scientists easily characterize and assess muscle activation patterns during cyclical movements.Approach.CIMAP(Clustering for the Identification of Muscle Activation Patterns) is an open-source Python toolbox based on agglomerative hierarchical clustering that aims at characterizing muscle activation patterns during cyclical movements by grouping movement cycles showing similar muscle activity.Main results.From muscle activation intervals to the graphical representation of the agglomerative hierarchical clustering dendrograms, the proposed toolbox offers a complete analysis framework for enabling the assessment of muscle activation patterns. The toolbox can be flexibly modified to comply with the necessities of the scientist.CIMAPis addressed to scientists of any programming skill level working in different research areas such as biomedical engineering, robotics, sports, clinics, biomechanics, and neuroscience. CIMAP is freely available on GitHub (https://github.com/Biolab-PoliTO/CIMAP).Significance.CIMAPtoolbox offers scientists a standardized method for analyzing muscle activation patterns during cyclical movements.

Impact of temperature-dependent viscosity on linear and weakly nonlinear stability of double-diffusive convection in viscoelastic fluid

The impact of temperature-dependent viscosity on the double-diffusive viscoelastic convective fluids is investigated, with applications in heat transfer, polymer processing, food industry, biomedical engineering, etc. Both linear and weakly nonlinear analyses are carried out to determine the stability of fluids using the Oldroyd-B model. Analytical criteria for the onset of linear stationary and oscillatory convection are derived. The effects of rheological parameters, linearly and exponentially varying viscosity, salinity Rayleigh number and Prandtl number on the system’s stability are investigated. Linear stability analysis reveals that the interaction between thermal and solute diffusions with rheological parameters favours oscillatory convection over stationary convection. In weakly nonlinear theory, a power series expansion derives a Landau amplitude equation, allowing heat and mass transfer analysis in viscoelastic fluids with temperature-dependent viscosity. Numerical results highlight the effects of variable viscosity on heat and mass transfer rates, represented by Nusselt and Sherwood numbers. Further, the weakly non-linear stability analysis evaluates the impact of the Prandtl number, rheological parameters and salinity Rayleigh number on heat and mass transfer rates. These findings are compared with existing results to validate and enhance our understanding of fluid behaviour under different conditions.

Effect of thin film thickness of ferrofluid on inclined bioconvective flow

This research examines the effect of variable thin film thickness on the bioconvective ferrofluid flow through a rotating sloped surface when a magnetic field (dipole) is present. Similarity transformation is used to standardize the current model's governing equations. By using a finite element method, the normalized nonlinear differential equations are numerically solved. Variable thickness of ferrofluid thin film and bioconvective parameters (bioconvective Lewis number, bioconvective Peclet number, and micro-organism concentration difference) yield the following results: velocity profiles (radial, tangential, and axial), gravity flow (drainage velocity and induced velocity), temperature profile, concentration profile and microorganism profile. In addition, this investigation examines the density of moving microorganisms as well as local heat and mass transport. The temperature, concentration, radial, axial, drainage, induced, and motile microbe velocity are all improved with increasing film thickness. Variable thickness increases local heat transfer whereas increasing Brownian motion and thermophoresis parameters decreases it. This study could be helpful for self-sterilizing applications and biomedical engineering.

Electrically Conductive Lignin Reinforced Polyacrylic Acid/Hyaluronic Acid Scaffolds With PEDOT:HA Nanoparticles

ABSTRACTHydrogel materials are continually developing in biomedical engineering and recently a lot of effort has gone into their engineered performance in physiological applications. Porosity is an important characteristic for tissue engineering scaffolds to allow enhanced biocompatibility and the pore size needed is dependent on the application and type of tissue for which the hydrogel is being used to regenerate. Regarding biomedical applications, the use of conducting polymers is gaining in popularity due to their promising biocompatibility and potential to stimulate cell growth and proliferation through electrical stimulation. Building on previous hydrogel development by the authors, this study focuses on developing a biocompatible hydrogel scaffold with adjustable porosity and swelling capabilities, robust mechanical properties, electrical conductivity, and high thermal stability. The objective of this work is to examine the effect of freezing temperature, cross‐linker and porosity on the final characteristics of the scaffold and to then determine possible applications. The porosity, swelling degree, compression strength, biocompatibility, electrical conductivity, and thermal characteristics of the final material were analyzed and were found to be affected by the varied synthesis methods used. Overall, the synthesized scaffolds exhibit good biocompatibility with increased fluorescence over 3 days and over 70% cell viability, thermal stability up to 200°C and a range of swelling of 1725% to 8472%. They also portray robust mechanical properties with a Young's Moduli range of 11 kPa to 4.54 MPa and a porosity range of 0.78–71.98 μm depending on the synthesis methods used. Through variations in synthesis methods, highly porous, absorbent, and stable scaffolds have been synthesized. Notably, this single recipe is highly tailorable for use in a range of biomedical applications from tissue engineering to drug delivery and wound repair.

Single-Beam Acoustic Tweezers for Cell Biology: Molecular to In Vivo Level.

Acoustic tweezers have attracted attention in various fields of cell biology, including in vitro single-cell and intercellular mechanics. Compared with other tweezing technologies such as optical and magnetic tweezers, acoustic tweezers possess stronger forces and are safer for use in biological systems. However, due to the limited spatial resolution or limited size of target objects, acoustic tweezers have primarily been used to manipulate cells in vitro. To extend the advantages of acoustic tweezers to other levels (e.g., molecular and in vivo levels), researchers have recently developed various types of acoustic tweezers such as single-beam acoustic tweezers (SBATs), surface acoustic wave (SAW) tweezers, and acoustic-streaming tweezers. Among these, SBATs utilize a single-focused beam, making the transducer and system simple, noninvasive, and capable of producing strong forces compared with other types of tweezers. Depending on the acoustic beam pattern, SBATs can be classified into Rayleigh regime, Mie regime, and acoustic vortex with different trapping dynamics and application levels. In this review, we provide an overview of the principles and configuration of each type of SBAT, their applications ranging from molecular to in vivo studies, and their limitations and prospects. Thus, this review demonstrates the significance and potential of SBAT technology in biophysics and biomedical engineering.

Influence of space conjugate temperature varying non-uniform heat sink/source on hydromagnetic slip water-EG (50:50) nanofluid

Significant cooling is an essential requirement in the field of aeronautical and bio-medical engineering, nuclear reactor system, solar collectors, and in development of electronic chips etc. Involving rotating conical geometries. In view of this, flow and heat transfer over conical geometries subject to different constraints of motion are highly needed. Implementation of magnetic field subject to flow pattern controls the fluid motion thereby imparting better cooling. Consideration of nanofluid instead of regular fluid yields prominent cooling of the associated surface. Such relevance has motivated the authors to work on magnetohydrodynamics and heat transfer investigation of water-EG (50:50) mixture based Al2O3 and Fe3O4 past heated and rotating down-pointing upright cone subject to impact of space and temperature varying non-uniform heat source or sink. Numerical solution of dimensionless governing equations is accomplished by implementing Runge-Kutta method. The findings indicate that swirl and axial velocities peter out with rise in magnetic parameter while both exhibit opposite impact in response to slip parameter. Temperature profiles upgrade due to amplification of space and temperature dependent parameters. Skin friction and heat transportation upsurge with growth of solid volume fraction of nanoparticle.

Application of Laplace and Sumudu transforms to the modeling of unsteady rotating MHD flow in a second-grade tetra hybrid nanofluid in a porous medium

Understanding and managing the complex rheological behavior of fluid models is crucial for many real-world applications, such as industrial fluid dynamics, biomedical engineering, and environmental management. This study aims to predict the unsteady magnetohydrodynamic (MHD) flow of a second-grade tetra hybrid nanofluid in a porous medium containing uniformly dispersed dust particles. To address this challenge, we develop a mathematical model utilizing a non-fractional approach with ramping conditions. Our methodology incorporates Laplace and Sumudu transforms to analyze the velocity fields of both the fluid and dust particles. Additionally, we examine the heat transfer characteristics and the underlying dynamics of the magnetized second-grade tetra hybrid nanofluid flow. The momentum transfer of the dust particles is modeled using a separate equation. Key outcomes of this research include visual representations of novel findings, facilitating comparison with existing literature. Numerical simulations based on Sumudu and Laplace transformations produce velocity profiles for both fluid and dust particles, as well as temperature distributions, aligning with theoretical expectations. These results demonstrate the effectiveness of Laplace and Sumudu transforms in analyzing and simulating the turbulent MHD flow of nanofluids through porous media with dispersed dust particles.

Organelle Targeted Drug Delivery: Key Challenges, Recent Advancements and Therapeutic Implications.

Organelle-specific targeted drug delivery has emerged as a promising approach in the field of drug delivery and therapeutics. This innovative strategy involves the precise delivery of therapeutic agents to specific organelles within cells, such as the nucleus, mitochondria, endoplasmic reticulum, or lysosomes, with the aim of enhancing drug efficacy while minimizing offtarget effects. Despite its tremendous potential, organelle-specific drug delivery faces several key challenges. One major challenge is the development of delivery systems that can accurately navigate the complex intracellular environment and deliver drugs exclusively to the desired organelles. Achieving this level of precision demands advanced nanotechnology and biomaterials engineering. Furthermore, ensuring the safety and biocompatibility of these delivery systems is paramount. Recent advancements in this field include the development of nanocarriers, such as liposomes, nanoparticles, and dendrimers, designed to target specific organelles through ligandreceptor interactions or pH-responsive mechanisms. Additionally, advancements in molecular biology and genetic engineering have enabled the design of genetically encoded organellespecific drug delivery systems. The therapeutic implications of organelle-specific drug delivery are vast. This approach has the potential to revolutionize the treatment of diseases with organelle- specific pathologies, such as neurodegenerative disorders, cancer, and mitochondrial diseases. By precisely targeting the organelles involved in disease progression, the efficacy of therapies can be significantly improved while minimizing collateral damage to healthy tissues.

Flow analysis and fabrication of micro scale controlled surfaces by ultrashort pulse laser for microfluidic device applications

Microfluidics finds a wide range of industrial applications mainly in fields such as biomedical, clinical, electrical, and thermal engineering. Microchannels are the building blocks of most microfluidic devices. Thus, it becomes evident to understand the properties and the effect of the surfaces on the outcomes of devices. In this study, the effect of the shape of microchannels and the roughness elements on the flow is evaluated. Microchannels with three cross-sections and roughness elements of three different geometries are considered. The effect of varying Reynolds numbers on the flow parameters such as Friction factor, Nusselt number, Poiseuille number, pressure drop and surface temperature at the base of the substrate is studied. It is observed that rough microchannels and rectangular roughness elements showed a higher Nusselt number than smooth microchannels. The rough microchannels with triangular roughness elements showed higher friction factors. The surface temperature is higher for the smooth microchannels with triangular roughness elements. Furthermore, to demonstrate the manufacturability of microfluidic channels with controlled surfaces and to validate the preliminary results of the numerical simulations, the ultrashort pulse laser micromachining technique is used to fabricate the microchannels with structures on Polymethyl Methacrylate (PMMA) material.

Electrospun zeolitic imidazole framework-8 loaded silk fibroin/polycaprolactone nanofibrous scaffolds for biomedical application

The development of electrospun nanofibrous scaffolds (NFSs) have aroused much attraction in the field of biomedical engineering, due to their small fiber diameter, high specific surface area, and excellent extracellular matrix comparability. The main focus of this study is to design and fabricate novel zeolitic imidazole framework-8 (ZIF-8)-loaded silk fibrin/polycaprolactone (SF/PCL) nanofiber composite scaffolds by using the electrospinning strategy. Firstly, ZIF-8 was synthesized and characterized, which showed remarkable features in terms of shape, size, chemical and physical properties. Then, three different amounts of ZIF-8 were encapsulated into SF/PCL nanofibers during electrospinning, to investigate how the addition of ZIF-8 affected the morphology, and structure, as well as physical, mechanical, and biological properties of the nanofiber composite scaffolds. It was found that the addition of ZIF-8 didn't change the nanofibrous morphology of the composite scaffold, and no bead-like structure were found for the SF/PCL composite scaffolds loading with or without ZIF-8. The appropriate addition of ZIF-8 could significantly increase the mechanical properties of SF/PCL NFSs. The SF/PCL NFS containing 5% ZIF-8 showed high ultimate stress and initial modulus, which were 40.31 ± 2.31 MPa, and 569.19 ± 21.38 MPa, respectively. Furthermore, the MTT assay indicated that the pure SF/PCL scaffold and one with 1% ZIF-8 exhibited nearly identical cell compatibility toward human dermal fibroblast (HDF) cells, but some obvious cytotoxicity was observed with the increase of ZIF-8 content. However, the incorporation of ZIF-8 into SF/PCL NFSs was found to have excellent antibacterial rate against both E. coli and S. aureus. In all, the incorporation of 1% ZIF-8 could impart the SF/PCL NFS with balanced bio-function, making it a promising candidate for diverse biomedical applications such as tissue engineering and wound healing.

IEEE Transactions on Biomedical Engineering Information for Authors

IEEE Transactions on Biomedical Engineering Information for Authors

Integrated Approach To Material Parameterization And Inflation Control Of Hyperelastic Membrane For Artificial Left Ventricle Development

Abstract In transitioning from conventional mechanical to biomedical applications, the choice of materials becomes critical. While hard materials like steel offer durability, their compatibility with biological systems, particularly blood, is limited due to the risk of cell damage. To address this, our research focuses on soft membrane-based systems to minimize haemolysis and optimize blood flow. By prioritizing biocompatibility and gentle interactions, our approach aims to enhance the safety and effectiveness of biomedical devices. Through innovative solutions in material selection and system design, we aim to advance cardiovascular medicine and contribute to the broader field of biomedical engineering.

Abstracts of the 2024 Annual Meeting of the Austrian Society for Biomedical Engineering (ÖGBMT)

Abstracts of the 2024 Annual Meeting of the Austrian Society for Biomedical Engineering (ÖGBMT)

A Fetal Health Classification Approach Based on Broad Learning System

Abstract Fetal health problems are still a serious issue nowadays, affecting mothers and their children. The rate of mortality caused by fetal health problems is notably high in some areas of the earth, especially in lower-income countries. At present, besides the conventional clinical assessment, the methods of fetal health classification are mainly traditional machine learning and deep learning, such as KNN, SVM, Logistic Regression, and Naive Bayes, with the problems of low precision or long training time. In this study, we apply the broad learning system (BLS) to fetal health classification. The data set is sourced from the UCI ML repository database, which is made available by the Biomedical Engineering Institute and the University of Porto’s Faculty of Medicine. With the training accuracy of 92%, training time of 0.52s, and testing accuracy of 90%, the experimental results that highly satisfactory on BLS in the experiment.

Can boundary slip destabilize rotating microchannel flows?

Deviation from the traditional no-slip boundary condition due to factors like surface roughness and wettability is of paramount importance in microfluidics and nanofluidics, as it is attributable to its significance in drag reduction, flow control and enhancement and improved mixing. Augmentation in mixing, in turn, is known to strongly correlate with potential instabilities in the flow structure. Reported research studies indicate that slip is an inherent flow stabilizer in microfluidics, to the extent that with sufficient slip, the flow becomes linearly stable against all wavelike disturbances for all wavelengths and Reynolds numbers [“The linear stability of slip channel flows,” Phys. Fluids 34,074103(2022)]. Contrary to such intuitive proposition, here we show that slip effects can destabilize microchannel flows under spanwise rotation, delving on the interplay of rotational forces and slippery hydrodynamics. Our results reveal that increasing the slip length decreases the critical rotation speed, indicating lower rotational effort required to destabilize the flow, whereas the critical Reynolds number for the flow remains effectively unaltered for different slip lengths in a spanwise rotating system. As the slip length increases progressively, the critical rotation number (dimensionless rotational speed) for the onset of instability decreases further, then remains constant up to a certain limit, and subsequently declines with additional enhancement in the slip length. This indicates the potential for deploying customized hydrophobic (slippery) substrates to facilitate transitions from stable to unstable modes by simple tuning of the rotational speed—a paradigm that offers great promise in various applications ranging from materials synthesis to biomedical technology.