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Background: Conventional techniques used in oral and maxillofacial reconstruction focus mainly on utilizing autologous tissues that have unquestionably improved function and esthetics for many patients, worldwide. However, the success depends on countless factors such as: donor and recipient sites conditions, patient’s medical history, surgeon’s experience, restricted availability of high-quality autogenous tissues or stem cells, and increased surgical cost and time. Materials and Methods: Lately, teaming researchers, scientists, surgeons, and engineers, to address these limitations, have allowed tremendous progress in recombinant protein therapy, cell-based therapy, and gene therapy. Results: Over the past few years, biomedical engineering has been evolving from the laboratory to clinical applications, for replacement of damaged body tissues due to trauma, cancer, congenital or acquired disorders. Conclusions: This review provides an outlook on the content, benefits, recent advances, limitations, and future expectations of biomedical engineering for salivary glands, oral mucosa, dental structures, and maxillofacial reconstruction.

Summary: Excellent biocompatibility of liquid metals is the basis for developing biomedical applications, such as implantable devices, drug delivery, and tumor therapy. Especially, a systematic study to reveal the influence of gallium-based liquid metals on the composition of blood while they are used in the human body is vital but missing. Here, the compatibility of three kinds of frequently used gallium-based liquid metals with human blood and serum was explored systematically. The results show that treating blood and serum with gallium-based liquid metals did not cause hemolysis, suggesting red blood cells are not damaged or ruptured, and treatment had a negligible effect on the components in the blood. Additionally, the serum levels of glucose, cholesterol, and liver function molecules showed no change after adding liquid metals. These findings suggest that liquid metals have high compatibility with human blood and serum and are conductive to be applied in the fields of biomedical engineering.

This work investigated the facile synthesis of porous scaffold eggshell derived hydroxylapatite (ESHAp) as a composite with ammonium bicarbonate (AMB) for potential biomaterial in tissue engineering application. The phase purity, composition, size, functional groups and morphology of the apatite were elucidated using high resolution transmission electron microscopy (HTEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results showed that hydroxylapatite (HAp) nanoparticles have round morphologies with average diameters between 20 nm and 80 nm, FT-IR analysis confirmed significant hydroxylapatite functional groups like carbonate, phosphate, and hydroxyl groups, while XRD analysis revealed a well crystalline monophasic HAp powder. The scaffold samples containing 10, 20, 25 and 30 % of AMB withstood a compressive stress up to 5, 20, 30 and 42 N/mm2 respectively which indicates that the compressive stress increased with the AMB content introduced as the pore forming agent. MTT assay performed using MG63 osteosarcoma cell lines showed that on comparing the sample of ESTHAp which contained 0 % AMB with other samples in the range of 0.01–1 mM, viability of above 85 % MG63 cells was achieved except for ESTHAp with 40 % AMB, which showed some level of toxicity. The cell adhesion studies of sintered ESTHAp porous scaffold with different weight percent of the pore forming agents using inverted microscopic images of MG 63 cells incubated with ESTHAp samples and treated with heat at 1000 °C appeared to be unstable in the media used with particle leaching observed, and no cells observed near to the samples.

The corneal eye diseases such as Keratoconus cause weakening of the cornea, with this disease the cornea can change in shape. This condition affects between 1 in 3,000 to 1 in 10,000 people. The main reason for the development of such conditions is unknown and can have significant impacts. Over the last decade, with advancements in computerized corneal topography assessments, researchers have increasingly expressed interest in corneal topography for research as well as clinical activities. Up till now, several aspheric numerical models have been developed as well as proposed to define the complex shape of the cornea. A commonly used term for characterizing the asphericity in an eye is the Q value, a common indicator of the aspherical degree of the cornea. It is one of the critical parameters in the mathematical description model of the cornea as it represents the cornea's shape and the eye's characteristics. Due to the utmost importance of this Q value of the cornea, a couple of studies have attempted to explore this parameter and its distribution, merely in terms of its influence on the human eye's optical properties. The corneal Q value is an important factor that needs to be determined to treat for any refractive errors as corneal degeneration are disease that can lead to potential problems with the structure of the cornea. This study aims to highlight the need to understand Q value of the cornea as this can essentially assist with personalising corneal refractive surgeries and implantation of intraocular lenses. Therefore, the relevance of corneal Q value must be studied in association with different patients, especially ones who have been diagnosed with cataracts, brain tumours, or even COVID-19. To address this issue, this paper first carries out a literature review on the optics of the cornea, the relevance of corneal Q value in ophthalmic practice and studies corneal degenerations and its causes. Thereafter, a detailed review of several noteworthy relevant research studies examining the Q value of the cornea is performed. To do so, an elaborate database is created, which presents a list of different research works examined in this study and provides key evidence derived from these studies. This includes listing details on the age, gender, ethnicity of the eyes assessed, the control variables, the technology used in the study, and even more. The database also delivers important findings and conclusions noted in each study assessed. Next, this paper analyses and discusses the magnitude of corneal Q value in various scenarios and the influence of different parameters on corneal Q value. To design visual optical products as well as to enhance the understanding of the optical properties of an eye, future studies could consider the database and work presented in this study as useful references. In addition, the work can be used to make informed decisions in clinical practice for designing visual optical products as well as to enhance the understanding of the optical properties of an Eye.

Summary: We introduce SolunumWear, a multi-sensory e-textile system designed for respiration in daily life settings, addressing the gap in continuous, real-world respiration event monitoring. Leveraging a textile pressure sensor belt to capture chest movements and a wireless data acquisition system, SolunumWear offers a promising solution for both medical and wellness applications. The system’s efficacy was evaluated through a human study involving 10 healthy adults (six female and four male) across various breathing rates and postures, demonstrating a strong correlation (R value = 0.836) with the gold-standard system. The study highlights the system’s computational and communication efficiencies, with latencies of approximately 4.84 s and 2.13 ms, respectively. These findings highlight the efficacy of SolunumWear as a wireless, wearable technology for respiration monitoring in daily settings. This research contributes to the expanding body of knowledge on smart textile-based health monitoring technologies, demonstrating its potential to provide reliable respiratory data in real-world environments.

Summary: Sorafenib, a first-line drug for advanced hepatocellular carcinoma (HCC), unfortunately encounters resistance in most patients, leading to disease progression. Traditional approaches to counteract this resistance, particularly those targeting the RAF-MEK-ERK pathway, often face clinical feasibility limitations. Magnetic hyperthermia (MH), unlike conventional thermal therapies, emerges as a promising alternative. It uniquely combines magnetothermal effects with an increase in reactive oxygen species (ROS). This study found the potential of intracellular MH enhanced the efficacy of sorafenib, increased cellular sensitivity to sorafenib, and reversed sorafenib resistance by inhibiting the RAF-MEK-ERK pathway in an ROS-dependent manner in a sorafenib-resistant HCC cell. Further, in a sorafenib-resistant HCC mouse model, MH significantly sensitized tumors to sorafenib therapy, resulting in inhibited tumor growth and improved survival rates. This presents a promising strategy to overcome sorafenib resistance in HCC, potentially enhancing therapeutic outcomes for patients with this challenging condition.

Due to the risk of releasing carcinogenic nickel ions from conventional 316L stainless steel under a corrosive human body environment, a new variant of steel termed nickel-free stainless steel (NiFSS) has been investigated. The present study investigates the tribological properties and biocompatibility of NiFSS manufactured via laser powder bed fusion (PBF-LB/M). The ferritic NiFSS exhibited significantly lower coefficient of friction (0.08 to 0.28) and wear rate (1.60 × 10-6 mm3/Nm to 6.60 × 10-6 mm3/Nm) compared to reported values for austenitic 316L SS, under both dry and simulated body fluid (SBF) conditions and various sliding geometries. This improvement is attributed to the superior hardness (3.394 ± 0.1340 GPa) and elastic modulus (238 ± 9.0797 GPa) of NiFSS. To assess the biocompatibility, the viability of mouse pre-osteoblastic MC3T3-E1 cells was evaluated with an Alamar Blue assay when the cells were cultured on top of PBF-LB/M built NiFSS and 316L SS samples. The results indicated that even though cell growth was most optimal on regular cell culture plastic, cell viability was better maintained on PBF-LB/M built NiFSS compared to 316L SS. Therefore, the results of the present study propose that PBF-LB/M fabricated NiFSS holds promise for application in biomedical devices for joint arthroplasty.

Using a low-compaction protocol, the optimum sintering dwell time for fabricating hydroxyapatite (HA) scaffolds was investigated. HA was synthesized through a facile direct thermal conversion approach using a calcination temperature of 900 °C at 2, 4, and 6 h dwell times. The structure and composition of the powders were determined by X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX), and Fourier transform infrared (FTIR) analysis. In addition, porosity measurements were also conducted. Complementarily, computational simulations were conducted from first principles using density functional theory (DFT) with four different exchange-correlation functionals to calculate the structural properties and hardness of the bulk HA crystal. These calculations were done to identify the exchange-correlation functionals that closely agree with the experimental data in this study. The results revealed that with increasing sintering dwell time, the crystallite sizes of the HA powder decreased slightly from 23.62 nm to 23.37 nm, then increased to 34.15 nm. The microhardness of the samples, pre-immersion in phosphate buffer saline (PBS) for 2, 4, and 6 h were 0.38, 0.42, and 0.50 GPa, respectively, whereas post-immersion, the values of the microhardness reached 0.32, 0.48 and 0.54 GPa, respectively. The highest porosity values were 59.3% and 39.3%, observed for samples sintered at 6 h dwell times using the two methods, indicating more open pores. Conclusively, longer sintering dwell time corresponded to better mechanical properties both pre- and post-immersion in simulated body fluid. It was observed that the results from PBE-D3-BJ and optB88-vdW functionals agree better with experimental data for the lattice constants and the values are relatively close to the microhardness obtained experimentally. The reasons for a significant deviation of the microhardness values from the computational and experimental standpoint are discussed herein.

Needle-type sensor, characterized by its slender, elongated shape, is a promising sensing method due to its rapid response, high sensitivity, and portability. Recently, the needle-type sensor technology has garnered increasing attention, leading to its accelerated development and extensive use in medical and healthcare, environmental monitoring, and geosciences. However, there remains a need for a comprehensive review of existing research. Here, we utilize scientometric analysis, which is booming recently, to conduct a comprehensive investigation of the needle-type sensor field. This analysis covers various aspects, including annual trends, journals, institutions, countries, disciplines, authors, references, and keywords of 136,667 publications from the Web of Science Core Collection (WoSCC) database spanning from January 1, 2004, to January 1, 2024. Additionally, we identify current hotspots, frontiers, and predict future trends. Eventually, three research hotspots are refined: multidisciplinary materials science, sensor miniaturization and integration, and biomedical engineering, indicating that further investigations may focus on creating biocompatible materials to enhance sensing properties, optimizing sensor structure through miniaturization and integration methods, and improving clinical applications in biomedical engineering. This work may facilitate the development of needle-type sensors.

Summary: Protein-coated microbubbles have become one of the emerging platforms in biomedical research as theranostic agents. In recent years, microbubbles have been extensively used as ultrasound contrast agents and carriers of molecular cargoes, pertaining to which several studies have focused on tuning the properties of these bubbles to achieve a higher degree of biocompatibility and extended stability. Synthesis of microbubbles has so far been traditionally carried out with pre-heated proteins like bovine serum albumin (BSA) as shell coatings, owing to the ease in making BSA crosslinked structures through disulfide bridge formation. We, however, have performed experiments to demonstrate that air core microbubbles formed with native BSA are more stable compared with those formed using denatured BSA. The experimental observations have been supported with analytical modeling and computational studies, which offer insights into the effect of BSA conformation in stabilizing the microbubbles shells and prolonging their lifetimes.

Summary: The detection and classification of arrhythmias are crucial steps in diagnosing cardiovascular diseases. However, current deep learning-based classification methods often fail to consider both the morpho-logical and temporal features of the electrocardiogram (ECG) simultaneously. Therefore, we propose a hybrid heartbeat classification method that combines Transformer and multi branch convolutional neural networks (CNNs). Then, use the fusion module to stitch the features obtained from different classifiers. We performed three different heartbeat classification protocols on the MIT-BIH arrhythmia (MIT-BIH-AR) database and analyzed performance on SVEB and VEB classes to validate our method. The first was an intra-patient protocol with an overall accuracy of 99.5%, with 92.4% and 99.9% for Sen and Spe on SVEB and 98.2% and 99.9% for Sen and Spe on VEB. The latter two were inter-patient protocols, and we divided the training and test sets using different records, and the results showed an overall accuracy of 98.8% and 97.2%, respectively.

Background: Tactile sensors are utilized to measure multichannel pulse signals in pulse wave analysis (PWA). Owing to noise interferences, researchers have applied various denoising algorithms on multichannel pulse signals. To comprehensively assess these algorithms, numerous evaluation metrics have been proposed. However, these studies did not investigate the noise mechanisms in depth and lacked reference pulse signals, thus making the evaluations insufficiently objective. Materials and methods: An applicable denoising evaluation approach for multichannel pulse signal algorithms based on an arterial pulse acquisition system is established by superimposing real-world multichannel noise to the reference signals. The system, comprising a SphygmoCor and a uniaxial noise acquisition device, allows us to acquire single-reference pulse signals as well as real-world multichannel noise. Results: We assess eight popular denoising algorithms with three evaluation metrics, including amplitude relative error (ARE), mean square error (MSE) and increased percentage signal-noise ratio (SNR%). Our proposed approach provides accurate and objective evaluations of multichannel pulse signal denoising. Notably, classic algorithms for single-channel denoising are not recommended for multichannel denoising. Comparatively, RPCA-based algorithms can denoise pulse signals independently for each channel. Conclusion: This study sets the stage for the establishment of accurate and objective pulse signal denoising evaluations and provides insights for data-driven clinical diagnoses in cardiovascular medicine.

The overlap between mechanical engineering and medicine is expanding more and more over the years. Engineers are now using their expertise to design and create functional biomaterials and are continually collaborating with physicians to improve patient health. In this review, we explore the state of scientific knowledge in the areas of biomaterials, biomechanics, nanomechanics, and computational fluid dynamics (CFD) in relation to the pharmaceutical and medical industry. Focusing on current research and breakthroughs, we provide an overview of how these fields are being used to create new technologies for medical treatments of human patients. Barriers and constraints in these fields, as well as ways to overcome them, are also described in this review. Finally, the potential for future advances in biomaterials to fundamentally change the current approach to medicine and biology is also discussed.

Summary: Nanobody, referred to the variable domain of heavy-chain-only antibodies, has several advantages such as small size and feasible Escherichia coli expression, making them promising for scientific research and therapies. Conventional nanobody screening and expression methods often suffer from the need for subcloning into expression vectors and amplification-induced diversity loss. Here, we developed an integrated method for simultaneous screening and expression. Nanobody libraries were cloned and secretly expressed in the culture medium. Target-specific nanobodies were isolated through 1–3 rounds of dilution and regrowth following the Poisson distribution. This ensured no dismissal of positive clones, with populations of positive clones increasing over 10-fold in each dilution round. Ultimately, we isolated 5 nanobodies against death domain receptor 5 and 5 against Pyrococcus furiosus DNA polymerase directly from their immunized libraries. Notably, our approach enables nanobody screening without specialized instruments, demonstrating broad applicability in routine monoclonal nanobody production for diverse biomedical applications.

Summary: Magnetocardiography (MCG) can be used to noninvasively measure the electrophysiological activity of myocardial cells. The high spatial resolution of magnetic source localization can precisely determine the location of cardiomyopathy, which is of great significance for the diagnosis and treatment of cardiovascular disease. To perform magnetic source localization, MCG data must be co-registered with anatomical images. We propose a co-registration method that can be applied to OPM-MCG systems. In this method, the sensor array and the trunk of the subject are scanned using structured light-scanning technology, and the scan results are registered with the reconstructed structure using computed tomography (CT). This can increase the number of effective cloud points acquired and reduce the interference from respiratory motion. The scanning bed of the OPM-MCG system was modified to be consistent with the CT device, ensuring that the state of the body remains consistent between the cardiac magnetometry measurements and CT scans.

Summary: Cancer is a major health threat and a leading cause of human death worldwide. Surgical resection is the primary treatment for most cancers; however, some patients develop locoregional recurrence. Here, we developed an in situ cancer therapeutic system aimed to locally treat cancer and prevent postoperative recurrence. A functional scaffold, based on alginate/gelatin and crosslinked with copper ions, was fabricated by 3D printing and showed an excellent photothermal effect under near-infrared (NIR) irradiation. The combination of copper ions and NIR effectively killed thyroid cancer cells and patient-derived organoids, indicating a synergetic and broad-spectrum antitumor effect on thyroid cancer through the chemo-photothermal therapy. This implantable stent is designed to provide effective treatment in the vicinity of the tumor site and can be degraded without secondary surgery. The copper-loaded hydrogel scaffold may be a potential candidate for local cancer treatment and pave the way for precise and effective cancer therapy.

Summary: Articular cartilage tissue engineering is being considered an alternative treatment strategy for promoting cartilage damage repair. Herein, we proposed a modular hydrogel-based bioink containing microsphere-embedded chondrocytes for 3D printing multiscale scaffolds integrating the micro and macro environment of the native articular cartilage. Gelatin methacryloyl (GelMA)/alginate microsphere was prepared by a microfluidic approach, and the chondrocytes embedded in the microspheres remained viable after being frozen and resuscitated. The modular hydrogel bioink could be printed via the gel-in-gel 3D bioprinting strategy for fabricating the multiscale hydrogel-based scaffolds. Meanwhile, the cells cultured in the scaffolds showed good proliferation and differentiation. Furthermore, we also found that the composite hydrogel was biocompatible in vivo. These results indicated that the modular hydrogel-based bioinks containing microsphere-embedded chondrocytes for 3D printing multiscale scaffolds could provide a 3D multiscale environment for enhancing cartilage repairing, which would be encouraging considering the numerous alternative applications in articular cartilage tissue engineering.

Summary: The tumor heterogeneity, which leads to individual variations in tumor microenvironments, causes poor prognoses and limits therapeutic response. Emerging technology such as companion diagnostics (CDx) detects biomarkers and monitors therapeutic responses, allowing identification of patients who would benefit most from treatment. However, currently, most US Food and Drug Administration-approved CDx tests are designed to detect biomarkers in vitro and ex vivo, making it difficult to dynamically report variations of targets in vivo. Various medical imaging techniques offer dynamic measurement of tumor heterogeneity and treatment response, complementing CDx tests. Imaging-based companion diagnostics allow for patient stratification for targeted medicines and identification of patient populations benefiting from alternative therapeutic methods. This review summarizes recent developments in molecular imaging for predicting and assessing responses to cancer therapies, as well as the various biomarkers used in imaging-based CDx tests. We hope this review provides informative insights into imaging-based companion diagnostics and advances precision medicine.

Summary: Subsensory noise stimulation targeting sensory receptors has been shown to improve balance control in healthy and impaired individuals. However, the potential for application of this technique in other contexts is still unknown. Gait control and adaptation rely heavily on the input from proprioceptive organs in the muscles and joints. Here we investigated the use of subsensory noise stimulation as a means to influence motor control by altering proprioception during locomotor adaptations to forces delivered by a robot. The forces increase step length unilaterally and trigger an adaptive response that restores the original symmetry. Healthy participants performed two adaptation experiments, one with stimulation applied to the hamstring muscles and one without. We found that participants adapted faster but to a lesser extent when undergoing stimulation. We argue that this behavior is because of the dual effect that the stimulation has on the afferents encoding position and velocity in the muscle spindles.

Summary: Blood brain barrier disruption (BBBD) using focused ultrasound (FUS) and microbubbles (MB) is an effective tool for therapeutic delivery to the brain. BBBD depends to a great extent on MB oscillations. Because the brain vasculature is heterogenic in diameter, reduced MB oscillations in smaller blood vessels, together with a lower number of MBs in capillaries, can lead to variations in BBBD. Therefore, evaluating the impact of microvasculature diameter on BBBD is of great importance. We present a method to characterize molecules extravasation following FUS-mediated BBBD, at a single blood vessel resolution. Evans blue (EB) leakage was used as marker for BBBD, whereas blood vessels localization was done using FITC labeled Dextran. Automated image processing pipeline was developed to quantify the extent of extravasation as function of microvasculature diameter, including a wide range of vascular morphological parameters. Variations in MB vibrational response were observed in blood vessel mimicking fibers with varied diameters. Higher peak negative pressures (PNP) were required to initiate stable cavitation in fibers with smaller diameters. In vivo in the treated brains, EB extravasation increased as a function of blood vessel diameter. The percentage of strong BBBD blood vessels increased from 9.75% for 2–3 μm blood vessels to 91.67% for 9–10 μm. Using this method, it is possible to conduct a diameter-dependent analysis that measures vascular leakage resulting from FUS-mediated BBBD at a single blood vessel resolution.

Summary: This study explores the use of a brain-computer interface (BCI) based on motor imagery (MI) for the control of a lower limb exoskeleton to aid in motor recovery after a neural injury. The BCI was evaluated in ten able-bodied subjects and two patients with spinal cord injuries. Five able-bodied subjects underwent a virtual reality (VR) training session to accelerate training with the BCI. Results from this group were compared with a control group of five able-bodied subjects, and it was found that the employment of shorter training by VR did not reduce the effectiveness of the BCI and even improved it in some cases. Patients gave positive feedback about the system and were able to handle experimental sessions without reaching high levels of physical and mental exertion. These results are promising for the inclusion of BCI in rehabilitation programs, and future research should investigate the potential of the MI-based BCI system.

Summary: Nanozymes have attracted extensive research interest due to their ideal enzymatic catalytic performance; however, uncontrollable activities and nonspecific accumulation limit their further clinical application. To overcome these obstacles, we proposed in situ synthesized nanozyme, and realized the concept through an intelligent nanosystem (ISSzyme) based on Prussian blue (PB) precursor. PB nanozyme was synthesized at the tumor sites through the interaction of ISSzyme with glutathione, which was demonstrated by comparing with conventional PB nanozyme. ISSzyme is capable of tumor-specific photoacoustic imaging (PAI) and photothermal therapy (PTT), reducing the false-positive signals of PAI and the treatment side effects of PTT. ISSzyme has catalase-like activities, resulting in tumor hypoxia relief and metastasis inhibition. More importantly, the in situ synthesized PB nanozyme has the favorable property of minimal liver accumulation. Considering the above advantages, ISSzyme is expected to shed light on the design of the next-generation artificial enzymes, with many new biomedical applications.

Summary: Although both are applied in regenerative medicine, acellular dermal matrix (ADM) and concentrated growth factor (CGF) have their respective shortcoming: The functioning of CGF is often hindered by sudden release effects, among other problems, and ADM can only be used in outer dressing for wound healing. In this study, a compound network with physical-chemical double cross-linking was constructed using chemical cross-linking and the intertwining of ADM and chitosan chains under freezing conditions; equipped with good biocompatibility and cell/tissue affinity, the heparin-modified composite scaffold was able to significantly promote cell adhesion and proliferation to achieve adequate fixation and slow down the release of CGF; polydopamine nanoparticles having excellent near-infrared light photothermal conversion ability could significantly promote the survival of rat autologous skin grafts. In a word, this multifunctional composite scaffold is a promising new type of implant biomaterial capable of delivering CGF to promote the healing of full-thickness skin defects.

Summary: Oral and maxillofacial organoids, as three-dimensional study models of organs, have attracted increasing attention in tissue regeneration and disease modeling. However, traditional strategies for organoid construction still fail to precisely recapitulate the key characteristics of real organs, due to the difficulty in controlling the self-organization of cells in vitro. This review aims to summarize the recent progress of novel approaches to engineering oral and maxillofacial organoids. First, we introduced the necessary components and their roles in forming oral and maxillofacial organoids. Besides, we discussed cutting-edge technology in advancing the architecture and function of organoids, especially focusing on oral and maxillofacial tissue regeneration via novel strategy with designed cell-signal scaffold compounds. Finally, current limitations and future prospects of oral and maxillofacial organoids were represented to provide guidance for further disciplinary progression and clinical application to achieve organ regeneration.

Composites or composite materials are engineered materials that consist of two or more constituent materials with wide discrepancies in their physical, chemical, and mechanical properties. The characteristic properties of these composite are as a result of the individual properties of their constituent parts and their respective volume fractions and arrangements in the material system. Depending on the intended application, composites can be designed to satisfy specific geometrical, structural, mechanical, chemical, and sometimes aesthetic requirements. Areas of application of these synthetic materials includes construction such as in buildings and bridges, automotive industry such as in car bodies, aeronautic, naval (e.g., ships and boats), and in the biomedical fields. Although metallic, polymeric and ceramic biomaterials have been in use for medical treatments such as tissue repairs and replacements for decades, composites are just coming to light. Therefore, the main purpose of this paper is to introduce composite materials and discuss their current and potential use in the biomedical field.

Nanoscience-often summarized as "the future is tiny"-highlights the work of researchers advancing nanotechnology through incremental innovations. The design and innovation of new nanomaterials are vital for the development of next-generation three-dimensional (3D) printed structures characterized by low cost, high speed, and versatile capabilities, delivering exceptional performance in advanced applications. The integration of nanofillers into polymeric-based inks for 3D printing heralds a new era in additive manufacturing, allowing for the creation of custom-designed 3D objects with enhanced multifunctionality. To optimize the use of nanomaterials in 3D printing, effective disaggregation techniques and strong interfacial adhesion between nanofillers and polymer matrices are essential. This review provides an overview of the application of various types of nanomaterials used in 3D printing, focusing on their functionalization principles, dispersion strategies, and colloidal stability, as well as the methodologies for aligning nanofillers within the 3D printing framework. It discusses dispersive methods, synergistic dispersion, and in-situ growth, which have yielded smart 3D-printed structures with unique functionality for specific applications. This review also focuses on nanomaterial alignment in 3D printing, detailing methods that enhance selective deposition and orientation of nanofillers within established and customized printing techniques. By emphasizing alignment strategies, we explore their impact on the performance of 3D-printed composites and highlight potential applications that benefit from ordered nanoparticles. Through these continuing efforts, this review shows that the design and development of the new class of nanomaterials are crucial to developing the next generation of smart 3D printed architectures with versatile abilities for advanced structures with exceptional performance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Nanocellulose, a versatile biopolymer renowned for its exceptional physicochemical attributes including lightweight, biocompatibility, biodegradability, and higher mechanical strength properties has captured significant attention in biomedical research. This renewable material, extracted from widely abundant biosources including plants, bacteria, and algae, exists in three primary forms: cellulose-based nanocrystals (CNCs), nanofibrils (CNFs), and bacterial nanocellulose (BNC). CNCs are characterized by their highly crystalline, needle-shaped structure, while CNFs possess a blend of amorphous and crystalline regions. BNC stands out as the purest form of nanocellulose. Chemical functionalization enables precise tuning of nanocellulose properties, enhancing its suitability for diverse biomedical applications. In drug delivery systems, nanocellulose's unique structure and surface chemistry offer opportunities for targeted delivery of active molecules. Surface-modified nanocellulose can effectively deliver drugs to specific sites, utilizing its inherent properties to control drug release kinetics and improve therapeutic outcomes. Despite these advantages, challenges such as achieving optimal drug loading capacity and ensuring sustained drug release remain. Future research aims to address these challenges and explore novel applications of nano-structured cellulose in targeted drug delivery, highlighting the continued evolution of this promising biomaterial in biomedicine. Furthermore, the review delves into the impact of chemical, physical, and enzymatic methods for CNC surface modifications, showcasing how these approaches enhance the functionalization of CNCs for targeted delivery of different compounds in biological systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

An Electromyography (EMG) based pattern recognition system constitutes various steps of signal processing and control engineering from signal acquisition to real-time control. Efficient control of external devices largely depends on the signal processing steps executed before the final output. This work presents a new approach to signal processing using Motor Unit Action Potential (MUAP) based signal decomposition and segmentation. An MUAP is a neurological response during muscle contraction. Due to the higher contact area of surface electrodes, MUAPs from multiple muscles are captured. An MUAP generated from a single muscle usually has identical waveshapes and similar discharging rates and usually lasts for 8-15 ms. These are known as primary MUAPs. The proposed algorithm identifies and uses the primary observed MUAPs for feature extraction and classification. Firstly, noise signals are eliminated by a determined noise margin, which also separates the active muscle movement signals. Next, a novel MUAP identification algorithm is implemented to detect the MUAP trains. Then, identified primary MUAPs are used to make segments with variable widths to extract feature vectors. Based on the correlation score of all the primary MUAPs, the segmentation is performed, which results in segmentation width varying from 110-200 ms. The achieved segmentation width is lesser than the conventional overlapping and non-overlapping methods - the proposed approach results in a 20 to 50% reduction in the segmentation width. Four different classifiers are tested during the machine learning stage to investigate the performance of the proposed approach. The obtained feature sets are then used to train the Linear Discriminant Analysis (LDA), K-Nearest Neighbor (kNN), Decision Tree (DT), and Random Forest (RF) classifiers. The classifiers are tested with precision, recall, F 1 score, and accuracy. The kNN and DT classifiers performed better than the LDA and RF classifiers. The maximum precision and recall are 100% while the maximum achieved accuracy is 98.56%. The comparative results show higher accuracy even at lower segmentation widths than the conventional constant window scheme. The kNN and DT classifiers provide a 5% to 15% increment in accuracy compared to the constant window segmentation-based approach., Competing Interests: Declaration of competing interest The authors declare that this manuscript is original, has not been published before and is not currently being considered for publication elsewhere. The authors confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. They further confirm that the order of authors listed in the manuscript has been approved by all of them. The author understand that the Corresponding Author is the sole contact for the Editorial process and is responsible for communicating with the other authors about progress, submissions of revisions and final approval of proofs., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Eco-friendly materials have emerged in biomedical engineering, driving major advances in chitosan-based hydrogels. These hydrogels offer a promising green alternative to conventional polymers due to their non-toxicity, biodegradability, biocompatibility, environmental friendliness, affordability, and easy accessibility. Known for their remarkable properties such as drug encapsulation, delivery capabilities, biosensing, functional scaffolding, and antimicrobial behavior, chitosan hydrogels are at the forefront of biomedical research. This paper explores the fabrication and modification methods of chitosan hydrogels for diverse applications, highlighting their role in advancing climate-neutral healthcare technologies. It reviews significant scientific advancements and trends chitosan hydrogels focusing on cancer diagnosis, drug delivery, and wound care. Additionally, it addresses current challenges and green synthesis practices that support a circular economy, enhancing biomedical sustainability. By providing an in-depth analysis of the latest evidence on climate-neutral management, this review aims to facilitate informed decision-making and foster the development of sustainable strategies leveraging chitosan hydrogel technology. The insights from this comprehensive examination are pivotal for steering future research and applications in sustainable biomedical solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Summary: Decellularization of esophagi from several species for tissue engineering is well described, but successful implantation in animal models of esophageal replacement has been challenging. The purpose of this study was to assess feasibility and applicability of esophageal replacement using decellularized porcine esophageal scaffolds in a new pre-clinical model. Following surgical replacement in rabbits with a vascularizing muscle flap, we observed successful anastomoses of decellularized scaffolds, cues of early neovascularization, and prevention of luminal collapse by the use of biodegradable stents. However, despite the success of the surgical procedure, the long-term survival was limited by the fragility of the animal model. Our results indicate that transplantation of a decellularized porcine scaffold is possible and vascular flaps may be useful to provide a vascular supply, but long-term outcomes require further pre-clinical testing in a different large animal model.

Summary: Allo-HSCT is a curative therapy for hematologic malignancies owing to GvL effect mediated by alloreactive T cells; however, the same T cells also mediate GvHD, a severe side effect limiting the widespread application of allo-HSCT in clinics. Invariant natural killer T (iNKT) cells can ameliorate GvHD while preserving GvL effect, but the clinical application of these cells is restricted by their scarcity. Here, we report the successful generation of third-party HSC-engineered human iNKT (3rdHSC-iNKT) cells using a method combining HSC gene engineering and in vitro HSC differentiation. The 3rdHSC-iNKT cells closely resembled the CD4−CD8−/+ subsets of endogenous human iNKT cells in phenotype and functionality. These cells displayed potent anti-GvHD functions by eliminating antigen-presenting myeloid cells in vitro and in xenograft models without negatively impacting tumor eradication by allogeneic T cells in preclinical models of lymphoma and leukemia, supporting 3rdHSC-iNKT cells as a promising off-the-shelf cell therapy candidate for GvHD prophylaxis.

Summary: Species differences in brain and blood–brain barrier (BBB) biology hamper the translation of findings from animal models to humans, impeding the development of therapeutics for brain diseases. Here, we present a human organotypic microphysiological system (MPS) that includes endothelial-like cells, pericytes, glia, and cortical neurons and maintains BBB permeability at in vivo relevant levels. This human Brain-Chip engineered to recapitulate critical aspects of the complex interactions that mediate neuroinflammation and demonstrates significant improvements in clinical mimicry compared to previously reported similar MPS. In comparison to Transwell culture, the transcriptomic profiling of the Brain-Chip displayed significantly advanced similarity to the human adult cortex and enrichment in key neurobiological pathways. Exposure to TNF-α recreated the anticipated inflammatory environment shown by glia activation, increased release of proinflammatory cytokines, and compromised barrier permeability. We report the development of a robust brain MPS for mechanistic understanding of cell-cell interactions and BBB function during neuroinflammation.

Hydroxyapatite has recently played a crucial role in the sustainable development of biomedical applications. Publications related to hydroxyapatite as filler for biopolymers have exhibited an increasing trend due to the expanding research output. Based on the latest publications, the authors reviewed the research trends regarding hydroxyapatite use in biomedical applications. Analysis of the Scopus database using the keywords ‘hydroxyapatite” and “biomedical applications” determined that 1,714 papers were produced between 2012 and 2021. The number of publications related to these keywords more than doubled between 2012 (99) and 2021 (247). The hydrothermal method, solid-state reactions, the sol-gel process, emulsion, micro-emulsion, and mostly chemical precipitation were used to produce synthetic hydroxyapatite. Meanwhile, calcination, alkaline hydrolysis, precipitation, hydrothermal, and a combination of these techniques were used in producing natural hydroxyapatite. Studies in the current literature reveal that shell-based animal sources have been frequently used as hydroxyapatite resources during investigations concerning biomedical applications, while calcination was the extraction method most often applied. Essential trace elements of fish bone, oyster shell, and eggshell were also found in hydroxyapatite powder. Abalone mussel shell and eggshell showed Ca/P ratios closer to the stoichiometric ratio due to the use of effective extraction methods such as manipulating aging time or stirring process parameters. This review should greatly assist by offering scientific insights to support all the recommended future research works, not only that associated with biomedical applications.

In this work, the adaptive regulation of blood glucose (BG) in type I diabetic (T1D) patients is considered by developing a Multiple Model Adaptive Control (MMAC), where its estimation is based on Magdelaine's long-term glucose-insulin Model. The (MMAC) is built using a bank of Kalman- Bucy Filters (KBFs)with optimal state feedback controllers. Each KBF is based on a particular value of the equilibrium point for which, the optimal Linear Quadratic Servo (LQ-Servo) controller is designed. The total state estimation is resolved by the probabilistic weighted sum of the produced outputs of all filters based on measured glucose signal. Simulation results show that MMAC is capable of providing reliable estimation and regulation of insulin delivery. Moreover, the performance of the controlled glucose/insulin is improved by 99% compared with that when using a single KBF. The MMAC has accurately identified the glucose signal corresponding to the hypothesis models with an average accuracy of 96.4% for 5 tested patients. Robust performance has been tested with different initial conditions and disturbance.

The attention in lab-on-a-chip devices with their potent application in medical engineering has prolonged swiftly over the last ten years. Travelling through the technology development, innovative microfluidics devices shown enormous potential to lift the lab-on-a-chip biomedical research in traditions that are not imaginable using conventional techniques. The advances in the arena of microfluidics have prompted high-tech uprisings in numerous biomedical disciplines, including diagnostics, single-cell analysis, micro- and nano device fabrication, organ-in-chip platforms, and med-tech applications. The speedy development is motivated by the cumulative cooperation among central nanomaterials advances and innovative microfluidic aptitudes in the range of biomedical applications. Microfluidic gadgets presently undertake a significant part in numerous organic, synthetic, and designing applications, that have multiple approaches to create the vital channel and highlight measurements. In this review, the critical assessments on the frontiers of microfluidic platforms are carried out towards advancements in the microfluidic capabilities for the new-edge biomedical applications. It has been exhibited that microfluidics offers a scope of benefits contrasted with customary strategies, including further developed controllability and consistency specified by nanomaterial attributes. Herein, authors have discussed how innumerable nanomaterials empower the manufacture of microfluidic systems with advanced optical, mechanical, electrical chemical, and bio-interfacial properties ranging from the basics of microfluidics, various factors, types, and fabrication procedure to biomedical applications. A comprehensive investigation in the state-of-the-art usage of microfluidics in biomedical field is steered exemplarily to understand the significant advantages. Moreover, our assessment provides an interdisciplinary overview of modern microfabrication strategies that can be adopted for academic and industrial interests.

A compact low-temperature and atmospheric-pressure air plasma jet source is developed for the inactivation of oral bacteria. Electrical and optical measurements are carried out to understand the fundamental characteristics of the custom-built system. The adjustable operating parameters are optimized to regulate the length of the plasma plume and control the generation of the reactive species. Results show that the temperature of the plasma jet is around 40–45 °C during 5 min plasma-on, without inducing any thermal effects on bacterial cells. Importantly, the safety of the device is estimated by evaluating the current through the human body via an equivalent electrical circuit. Antibacterial studies indicate that the plasma jet can effectively inactivate E. coli, P. aeruginosa and S. aureus within 20 s. Further analysis on the morphology of bacterial cells and the intracellular DNA leakage is performed to evaluate the integrity of the cell. This study suggests that the developed portable air plasma jet can effectively deactivate oral bacteria and has great potential in future dental or clinical medical applications.