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Wee Kyung Lee, Sung Rae Shin Department of Nursing, Sahmyook University, Seoul, South KoreaCorrespondence: Sung Rae Shin, Department of Nursing, Sahmyook University, 815 Hwarang-ro, Nowon-gu, Seoul, 01795, South Korea, Tel +82-2-3399-1588, Fax +82-2-3399-1594, Email shinsr@syu.ac.krIntroduction: Emerging Infectious Diseases are one of the world’s leading causes of death, and preventive measures must be implemented to minimize human casualties. Research on preventive behavior relies on the preventive behavior scale and it has an impact on the findings.Purpose: This study aimed to develop an Emerging Infectious Diseases Preventive Health Behavior (EID-PHB) Scale and verify the validity and reliability of the complex models.Methods: Initial items were generated through a literature review and interviews, based on the proposed conceptual framework of transmission-based precautions. 14 experts reviewed the preliminary items for content validity and 20 adults for face validity. Data were collected online by a research company from April 28 to May 3, 2023. A total of 533 participants completed the survey, and subjects were assigned through simple random sampling. The first sample (n = 330) was used for item analysis and Exploratory Factor Analysis (EFA), and the second sample (n = 203) was used for Confirmatory Factor Analysis (CFA), convergent validity, discriminant validity, criterion validity, and reliability. The test-retest reliability was assessed in 34 adults.Results: The final instrument derived six components (droplet, contact, airborne, bloodborne, environmental prevention, and psychological coping), nine indicators, and 34 items. The CFA indicated that all the complex models had a good fit and the integrated factors were confirmed through validity tests. The Cronbach’s alpha for the 34 items was 0.92, and the criterion validity was verified (r = 0.85, p < 0.001).Conclusion: The EID-PHB is a valid and reliable tool that can be used to determine preventive behaviors against emerging infectious diseases. This tool is expected to provide a conceptual framework for future research, contribute to the clinical practice and education, and establish strategies and policies for improving individual and public health.Keywords: emerging infectious disease, health behavior, primary prevention, validation studies as topic

Periodontitis is a prevalent chronic, destructive inflammatory disease affecting tooth-supporting tissues in humans. Guided tissue regeneration strategies are widely utilized for periodontal tissue regeneration generally by using a periodontal membrane. The main role of these membranes is to establish a mechanical barrier that prevents the apical migration of the gingival epithelium and hence allowing the growth of periodontal ligament and bone tissue to selectively repopulate the root surface. Currently available membranes have limited bioactivity and regeneration potential. To address such challenges, an osteoconductive, antibacterial, and flexible poly(caprolactone) (PCL) composite membrane containing zinc oxide (ZnO) nanoparticles is developed. The membranes are fabricated through electrospinning of PCL and ZnO particles. The physical properties, mechanical characteristics, and in vitro degradation of the engineered membrane are studied in detail. Also, the osteoconductivity and antibacterial properties of the developed membrane are analyzed in vitro. Moreover, the functionality of the membrane is evaluated with a rat periodontal defect model. The results confirmed that the engineered membrane exerts both osteoconductive and antibacterial properties, demonstrating its great potential for periodontal tissue engineering.

In this article, the authors search for holism in Korean nursing practice. This is done by comparing Korean Nurses' Association standards of holistic nursing practices to American Holistic Nurses Association standards of holistic nursing practice. There are several similarities in the standards; however, gaps were identified in Korean holistic nursing practice. These disparities are explained by examining Korean history and culture. Recommendations are made for increasing holism in Korean nursing practice. [ABSTRACT FROM AUTHOR]

This study sought to characterize spermatogenesis and mature sperm within the spermatophore of Todarodes pacificus. The process of spermatogenesis in this species can be divided into four types: spermatogonium, spermatocyte, spermatid, and sperm. In spermatogonia, the nucleus occupies most of the cell, and a synaptonemal complex is observed in primary spermatocytes. The karyoplasm of secondary spermatocytes exhibits a clear distinction between euchromatin and heterochromatin. Spermatids can be further divided into early, mid, and late during spermiogenesis. In early spermatids, the karyoplasm appeared granular, and proacrosomal vesicles were found in the apical of nucleus. Mid spermatids featured a fibrillar karyoplasm, with well-developed mitochondria in the midpiece. The nucleus of late spermatids was elongated and rectangular, with a homogenized karyoplasm of increased electron density. A mitochondrial spur was present below the nucleus. In mature sperm within the spermatophore, the nucleus measures approximately 4.5 μM in length, and the karyoplasm has an irregular asterisk- shape with high electron density. The acrosome is blunt-cone shaped and approximately 0.7 μM long, whereas the axoneme of flagellum exhibits a typical 9+2 microtubular structure. One mitochondrial spur was shaped like a long triangular flag, containing numerous mitochondria in its upper region and electron-dense glycogen granules in its lower region., 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 Ltd.. All rights reserved.)

Bentonite clay nanoparticles assume a pivotal role in 3D bioprinting and tissue engineering by augmenting the mechanical rigidity and biological efficacy of hydrogels. In this investigation, Span80 was employed as a surfactant to facilitate the synthesis of uniformly sized bentonite nanoparticles measuring approximately 700 nm in diameter. The resultant hybrid hydrogel displaced a marked increase in compressive modulus, achieving a peak value of 17.5 kPa, including 1% bentonite twice that of the unmodified gelatin methacryloyl (GelMA). The discernible enhancements in the physical and biological characteristics of the hydrogel underscore its considerable potential for applications in tissue engineering. This includes heightened mechanical rigidity, robust cell viability, and a meticulously regulated degradation rate. While further examinations are imperative to evaluate the viability of the developed hydrogel comprehensively, its auspicious physical and biological attributes strongly suggest its potential utility in the domain of tissue engineering and bioprinting., (© 2025 Wiley Periodicals LLC.)

Microporous hydrogels have been widely used for delivering therapeutic cells. However, several critical issues, such as the lack of control over the harsh environment they are subjected to under pathological conditions and rapid egression of cells from the hydrogels, have produced limited therapeutic outcomes. To address these critical challenges, cell-tethering and hypoxic conditioning colloidal hydrogels containing mesenchymal stem cells (MSCs) are introduced to increase the productivity of paracrine factors locally and in a long-term manner. Cell-tethering colloidal hydrogels that are composed of tyramine-conjugated gelatin prevent cells from egressing through on-cell oxidative phenolic crosslinks while providing mechanical stimulation and interconnected microporous networks to allow for host-implant interactions. Oxygenating microparticles encapsulated in tyramine-conjugated colloidal microgels continuously generated oxygen for 2 weeks with rapid diffusion, resulting in maintaining a mild hypoxic condition while MSCs consumed oxygen under severe hypoxia. Synergistically, local retention of MSCs within the mild hypoxic-conditioned and mechanically robust colloidal hydrogels significantly increased the secretion of various angiogenic cytokines and chemokines. The oxygenating colloidal hydrogels induced anti-inflammatory responses, reduced cellular apoptosis, and promoted numerous large blood vessels in vivo. Finally, mice injected with the MSC-tethered oxygenating colloidal hydrogels significantly improved blood flow restoration and muscle regeneration in a hindlimb ischemia (HLI) model., (© 2024 Wiley‐VCH GmbH.)

A Customized wound patch for Advanced tissue Regeneration with Electric field (CARE), featuring an autonomous robot arm printing system guided by a computer vision-enabled guidance system for fast image recognition is introduced. CARE addresses the growing demand for flexible, stretchable, and wireless adhesive bioelectronics tailored for electrotherapy, which is suitable for rapid adaptation to individual patients and practical implementation in a comfortable design. The visual guidance system integrating a 6-axis robot arm enables scans from multiple angles to provide a 3D map of complex and curved wounds. The size of electrodes and the geometries of power-receiving coil are essential components of the CARE and are determined by a MATLAB simulation, ensuring efficient wireless power transfer. Three heterogeneous inks possessing different rheological behaviors can be extruded and printed sequentially on the flexible substrates, supporting fast manufacturing of large customized bioelectronic patches. CARE can stimulate wounds up to 10 mm in depth with an electric field strength of 88.8 mV mm -1 . In vitro studies reveal the ability to accelerate cell migration by a factor of 1.6 and 1.9 for human dermal fibroblasts and human umbilical vein endothelial cells, respectively. This study highlights the potential of CARE as a clinical wound therapy method to accelerate healing., (© 2024 Wiley‐VCH GmbH.)

A fully bio-based polyester polyol based on isosorbide (ISB) and dimer fatty acid (DA) was synthesized through esterification. An ISB-based polyester polyol (DIS) was developed to synthesize a bio-based polyurethane elastomer (PUE) with enhanced mechanical and self-healing properties. The rigid bicyclic structure of ISB improved tensile properties, while the urethane bonds formed between the hydroxyl groups in ISB and isocyanate exhibited reversible characteristics at elevated temperatures, significantly enhancing the self-healing performance of DIS-based PUE compared to the control PUE (self-healing efficiency: 98% for DIS-based PUE vs. 65% for control PUE). The dynamic mechanical and rheological properties of DIS-based PUE were investigated to confirm their relationship with self-healing performance. The DIS-based PUE, featuring reversible urethane bonds, demonstrated rapid stress relaxation and maintained constant normal stress under external stimuli, contributing to its improved self-healing capabilities. Thus, ISB can be regarded as a promising bio-resource for synthesizing bio-based polyester polyols and, consequently, PUE with superior mechanical and self-healing properties., Competing Interests: Se-Ra Shin is employed by Jungwoo Fine Co., Ltd and Dai-Soo Lee is employed by C&S partner. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as potential conflicts of interest.

Heart failure is characterized by intricate myocardial remodeling that impairs the heart's pumping and/or relaxation capacity, ultimately reducing cardiac output. It represents a major public health burden, given its high prevalence and associated morbidity and mortality rates, which continue to challenge healthcare systems worldwide. Despite advancements in medical science, there are no treatments that address the disease at its core. The development of three-dimensional engineered in vitro models that closely mimic the (patho)physiology and drug responses of the myocardium has the potential to revolutionize our insights and uncover new therapeutic avenues. Key aspects of these models include the precise replication of the extracellular matrix structure, cell composition, micro-architecture, mechanical and electrical properties, and relevant physiological and pathological stimuli, such as fluid flow, mechanical load, electrical signal propagation, and biochemical cues. Additionally, to fully capture heart failure and its diversity in vivo , it is crucial to consider factors such as age, gender, interactions with other organ systems and external influences-thereby recapitulating unique patient and disease phenotypes. This review details these model features and their significance in heart failure research, with the aim of enhancing future platforms that will deepen our understanding of the disease and facilitate the development of novel, effective therapies.

In vivo bioprinting, fabricating tissue-engineered implants directly in a patient, was recently developed to overcome the logistical and clinical limitations of traditional bioprinting. In vivo printing reduces the time to treatment, allows for real-time reconstructive adjustments, minimizes transportation challenges, improves adhesion to remnant tissue and ensuing tissue integration, and utilizes the body as a bioreactor. Unfortunately, most in vivo printers are frame-based systems with limited working areas that are incompatible with the human body and lack portability. Robotic arms have recently been used to resolve these challenges, but developed systems suffered from complex deposition or cross-linking modalities and lacked bioink temperature control, drastically limiting the use of biologically favorable bioinks. Here, we created a portable and affordable robotic arm bioprinter with precise control over bioink temperature. The system maintained biomaterial ink temperatures from 6 to 60 ± 0.05 °C. We tested a bioprinting optimization strategy with different temperature-sensitive bioinks. In addition, we engineered a personalized in vivo printing strategy derived from in situ scanning and model reconstruction that utilizes freely available and open-source software. We further demonstrated the benefits of human-derived bioinks made of blood components. The system and the proposed human-derived bioinks pave the way toward the personalization of scaffold-based regenerative medicine., Competing Interests: Quint, M. Samandari, I. Sinha, and A. Tamayol are co-founders of InPrint Bio. A. Tamayol is also a co-founder of 3D PenBone. Other authors declare no competing conflict of interest., (© 2024 Author(s).)

Engineering biomimetic tissue implants with human induced pluripotent stem cells (hiPSCs) holds promise for repairing volumetric tissue loss. However, these implants face challenges in regenerative capability, survival, and geometric scalability at large-scale injury sites. Here, we present scalable vessel-integrated muscle-like lattices (VMLs), containing dense and aligned hiPSC-derived myofibers alongside passively perfusable vessel-like microchannels inside an endomysium-like supporting matrix using an embedded multimaterial bioprinting technology. The contractile and millimeter-long myofibers are created in mechanically tailored and nanofibrous extracellular matrix-based hydrogels. Incorporating vessel-like lattice enhances myofiber maturation in vitro and guides host vessel invasion in vivo, improving implant integration. Consequently, we demonstrate successful de novo muscle formation and muscle function restoration through a combinatorial effect between improved graft-host integration and its increased release of paracrine factors within volumetric muscle loss injury models. The proposed modular bioprinting technology enables scaling up to centimeter-sized prevascularized hiPSC-derived muscle tissues with custom geometries for next-generation muscle regenerative therapies., Competing Interests: Declaration of interests The authors declare no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Diabetic foot ulcers (DFUs) are a significant challenge in the clinical care of diabetic patients, often necessitating limb amputation and compromising the quality of life and life expectancy of this cohort. Minimally invasive therapies, such as modular scaffolds, are at the forefront of current DFU treatment, offering an efficient approach for administering therapeutics that accelerate tissue repair and regeneration. In this study, we report a facile method for fabricating granular nanofibrous microspheres (NMs) with predesigned structures and porosities. The proposed technology combines electrospinning and electrospraying to develop a therapeutic option for DFUs. Specifically, porous NMs were constructed using electrospun poly(lactic- co -glycolic acid) (PLGA):gelatin short nanofibers, followed by gelatin cross-linking. These NMs demonstrated enhanced cell adhesion to human dermal fibroblasts (HDF) during an in vitro cytocompatibility assessment. Notably, porous NMs displayed superior performance owing to their interconnected pores compared to nonporous NMs. Cell-laden NMs demonstrated higher Young's modulus values than NMs without loaded cells, suggesting improved material resiliency attributed to the reinforcement of cells and their secreted extracellular matrix. Dynamic injection studies on cell-laden NMs further elucidated their capacity to safeguard loaded cells under pressure. In addition, porous NMs promoted host cell infiltration, neovascularization, and re-epithelialization in a diabetic mouse wound model, signifying their effectiveness in healing diabetic wounds. Taken together, porous NMs hold significant potential as minimally invasive, injectable treatments that effectively promote tissue integration and regeneration.

Biological motions of native muscle tissues rely on the nervous system to interface movement with the surrounding environment. The neural innervation of muscles, crucial for regulating movement, is the fundamental infrastructure for swiftly responding to changes in body tissue requirements. This study introduces a bioelectronic neuromuscular robot integrated with the motor nervous system through electrical synapses to evoke cardiac muscle activities and steer robotic motion. Serving as an artificial brain and wirelessly regulating selective neural activation to initiate robot fin motion, a wireless frequency multiplexing bioelectronic device is used to control the robot. Frequency multiplexing bioelectronics enables the control of the robot locomotion speed and direction by modulating the flapping of the robot fins through the wireless motor innervation of cardiac muscles. The robots demonstrated an average locomotion speed of ~0.52 ± 0.22 millimeters per second, fin-flapping frequency up to 2.0 hertz, and turning locomotion path curvature of ~0.11 ± 0.04 radians per millimeter. These systems will contribute to the expansion of biohybrid machines into the brain-to-motor frontier for developing autonomous biohybrid systems capable of advanced adaptive motor control and learning.

Neurological disorders have for a long time been a global challenge dismissed by drug companies, especially due to the low efficiency of most therapeutic compounds to cross the brain capillary wall, that forms the blood-brain barrier (BBB) and reach the brain. This has boosted an incessant search for novel carriers and methodologies to drive these compounds throughout the BBB. However, it remains a challenge to artificially mimic the physiology and function of the human BBB, allowing a reliable, reproducible and throughput screening of these rapidly growing technologies and nanoformulations (NFs). To surpass these challenges, brain-on-a-chip (BoC) - advanced microphysiological platforms that emulate key features of the brain composition and functionality, with the potential to emulate pathophysiological signatures of neurological disorders, are emerging as a microfluidic tool to screen new brain-targeting drugs, investigate neuropathogenesis and reach personalized medicine. In this review, the advance of BoC as a bioengineered screening tool of new brain-targeting drugs and NFs, enabling to decipher the intricate nanotechnology-biology interface is discussed. Firstly, the main challenges to model the brain are outlined, then, examples of BoC platforms to recapitulate the neurodegenerative diseases and screen NFs are summarized, emphasizing the current most promising nanotechnological-based drug delivery strategies and lastly, the integration of high-throughput screening biosensing systems as possible cutting-edge technologies for an end-use perspective is discussed as future perspective., (© 2024. The Author(s).)

Periodontitis, a prevalent chronic inflammatory disease caused by bacteria, poses a significant challenge to current treatments by merely slowing their progression. Herein, we propose an innovative solution in the form of hierarchical nanostructured 3D printed bilayer membranes that serve as dual-drug delivery nanoplatforms and provide scaffold function for the regeneration of periodontal tissue. Nanocomposite hydrogels were prepared by combining lipid nanoparticle-loaded grape seed extract and simvastatin, as well as chitin nanocrystals, which were then 3D printed into a bilayer membrane that possesses antimicrobial properties and multiscale porosity for periodontal tissue regeneration. The constructs exhibited excellent mechanical properties by adding chitin nanocrystals and provided a sustained release of distinct drugs over 24 days. We demonstrated that the bilayer membranes are cytocompatible and have the ability to induce bone-forming markers in human mesenchymal stem cells, while showing potent antibacterial activity against pathogens associated with periodontitis. In vivo studies further confirmed the efficacy of bilayer membranes in enhancing alveolar bone regeneration and reducing inflammation in a periodontal defect model. This approach suggests promising avenues for the development of implantable constructs that not only combat infections, but also promote the regeneration of periodontal tissue, providing valuable insights into advanced periodontitis treatment strategies.

Myocardial infarction (MI) is a significant cardiovascular disease that restricts blood flow, resulting in massive cell death and leading to stiff and noncontractile fibrotic scar tissue formation. Recently, sustained oxygen release in the MI area has shown regeneration ability; however, improving its therapeutic efficiency for regenerative medicine remains challenging. Here, a combinatorial strategy for cardiac repair by developing cardioprotective and oxygenating hybrid hydrogels that locally sustain the release of stromal cell-derived factor-1 alpha (SDF) and oxygen for simultaneous activation of neovascularization at the infarct area is presented. A sustained release of oxygen and SDF from injectable, mechanically robust, and tissue-adhesive silk-based hybrid hydrogels is achieved. Enhanced endothelialization under normoxia and anoxia is observed. Furthermore, there is a marked improvement in vascularization that leads to an increment in cardiomyocyte survival by ≈30% and a reduction of the fibrotic scar formation in an MI animal rodent model. Improved left ventricular systolic and diastolic functions by ≈10% and 20%, respectively, with a ≈25% higher ejection fraction on day 7 are also observed. Therefore, local delivery of therapeutic oxygenating and cardioprotective hydrogels demonstrates beneficial effects on cardiac functional recovery for reparative therapy., (© 2024 Wiley‐VCH GmbH.)

Blood scarcity is one of the main causes of healthcare disruptions worldwide, with blood shortages occurring at an alarming rate. Over the last decades, blood substitutes has aimed at reinforcing the supply of blood, with several products (e.g., hemoglobin-based oxygen carriers, perfluorocarbons) achieving a limited degree of success. Regardless, there is still no widespread solution to this problem due to persistent challenges in product safety and scalability. In this Review, we describe different advances in the field of blood substitution, particularly in the development of artificial red blood cells, otherwise known as engineered erythrocytes. We categorize the different strategies into natural, synthetic, or hybrid approaches, and discuss their potential in terms of safety and scalability. We identify synthetic engineered erythrocytes as the most powerful approach, and describe erythrocytes from a materials engineering perspective. We review their biological structure and function, as well as explore different methods of assembling a material-based cell. Specifically, we discuss how to recreate size, shape, and deformability through particle fabrication, and how to recreate the functional machinery through synthetic biology and nanotechnology. We conclude by describing the versatile nature of synthetic erythrocytes in medicine and pharmaceuticals and propose specific directions for the field of erythrocyte engineering., Competing Interests: Conflicts of Interest P.J. is co-founder of LipoCoat B.V. All other authors declare no conflicts of interest.

Heart valve replacement surgeries are performed on patients suffering from abnormal heart valve function. In these operations, the problematic tissue is replaced with mechanical valves or with bioprosthetics that are being developed. The thrombotic effect of mechanical valves, reflecting the need for lifelong use of anticoagulation drugs, and the short-lived nature of biological valves make these two types of valves problematic. In addition, they cannot adapt to the somatic growth of young patients. Although decellularized scaffolds have shown some promise, a successful translation has so far evaded. Although decellularized porcine xenografts have been extensively studied in the literature, they have several disadvantages, such as a propensity for calcification in the implant model, a risk of porcine endogenous retrovirus (PERV) infection, and a high xenoantigen density. As seen in clinical data, it is clear that there are biocompatibility problems in almost all studies. However, since decellularized sheep heart valves have not been tried in the clinic, a large data pool could not be established. This review compares and contrasts decellularized porcine and sheep xenografts for heart valve tissue engineering. It reveals that decellularized sheep heart valves can be an alternative to pigs in terms of biocompatibility. In addition, it highlights the potential advantages of bioinks derived from the decellularized extracellular matrix in 3D bioprinting technology, emphasizing that they can be a new alternative for the application. We also outline the future prospects of using sheep xenografts for heart valve tissue engineering., Competing Interests: The authors report that there are no competing interests to declare., (© 2024 The Author(s). Bioengineering & Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.)

Background/objectives: Insulin resistance (IR) plays an important role in metabolic dysfunction-associated fatty liver disease (MAFLD) pathogenesis. A modified triglyceride-glucose (TyG) index, including TyG-body mass index (TyG-BMI) and TyG-waist circumference (TyG-WC), has been introduced to represent IR. This study aimed to investigate the diagnostic abilities of IR indices in MAFLD, in which fatty liver was diagnosed using computed tomography (CT). Subjects/methods: We retrospectively analyzed the clinical data and images of 852 adults aged ≥19 years who underwent abdominal CT. MAFLD was diagnosed based on the appearance of fatty liver on CT alongside at least one of the following three criteria: being overweight or obese, at least two metabolic risk abnormalities, and/or diabetes mellitus. IR indices were calculated by examining the following variables: homeostasis model assessment-IR, TyG index, TyG-BMI, TyG-WC, and visceral adiposity index. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve. Results: For all patients, the area under the curve (AUC) of the TyG index, TyG-BMI, and TyG-WC were 0.834, 0.938, and 0.942, respectively. In men, the AUC of the TyG index, TyG-BMI, and TyG-WC were 0.812, 0.928, and 0.934, respectively. In women, the AUC of the TyG index was 0.841, and TyG-BMI and TyG-WC were 0.940 and 0.953, respectively. The AUC values tended to increase in the following order: TyG index < TyG-BMI < TyG-WC. Women showed a higher AUC than men in all items, and the TyG-WC of women showed the highest value with AUC 0.953 (95% confidence interval [CI]: 0.892-1.000, P  < 0.0001). The AUC of the TyG index was 0.858 (95% CI: 0.828-0.888, P  < 0.0001). Conclusions: In conclusion, TyG-WC is a powerful surrogate marker for identifying MAFLD in clinical settings.

Noninvasive monitoring of biofabricated tissues during the biomanufacturing process is needed to obtain reproducible, healthy, and functional tissues. Measuring the levels of biomarkers secreted from tissues is a promising strategy to understand the status of tissues during biofabrication. Continuous and real-time information from cultivated tissues enables users to achieve scalable manufacturing. Label-free biosensors are promising candidates for detecting cell secretomes since they can be noninvasive and do not require labor-intensive processes such as cell lysing. Moreover, most conventional monitoring techniques are single-use, conducted at the end of the fabrication process, and, challengingly, are not permissive to in-line and continual detection. To address these challenges, we developed a noninvasive and continual monitoring platform to evaluate the status of cells during the biofabrication process, with a particular focus on monitoring the transient processes that stem cells go through during in vitro differentiation over extended periods. We designed and evaluated a reusable electrochemical immunosensor with the capacity for detecting trace amounts of secreted osteogenic markers, such as osteopontin (OPN). The sensor has a low limit of detection (LOD), high sensitivity, and outstanding selectivity in complex biological media. We used this OPN immunosensor to continuously monitor on-chip osteogenesis of human mesenchymal stem cells (hMSCs) cultured 2D and 3D hydrogel constructs inside a microfluidic bioreactor for more than a month and were able to observe changing levels of OPN secretion during culture. The proposed platform can potentially be adopted for monitoring a variety of biological applications and further developed into a fully automated system for applications in advanced cellular biomanufacturing.

Cerebrospinal fluid (CSF) leakage is a common complication of intradural surgery or incidental durotomy in neurosurgery. Dural suturing is a common method for durotomy repair, but this technique requires a long operation time and includes the risk of CSF leakage by incomplete sealing. Glue-type sealants are effective for watertight dural closure. However, unresolved shortcomings include insufficient sealing performance, poor biocompatibility, and excessive swelling. Here, a dural sealant using light-activated hyaluronic acid (HA) with multi-networks (HA photosealant) that provides fast sealing performance and high biocompatibility is reported. The HA photosealants form a watertight hydrogel barrier with multilength networks under low-energy visible light exposure (405 nm, <1 J cm -2 ) for 5 s and allow firm tissue adhesion on the wet dural surface. In a rabbit model of craniectomy and durotomy, HA photosealants exhibit the faster sealing performance of dural tears and enhance dural repair with accelerated bone formation compared to commercial surgical glues, with no degenerative changes, such as inflammation or necrosis, in histopathological evaluation. This biocompatible HA photosealant can be applied in a variety of clinical settings that require fast wound closure as a promising potential., (© 2023 Wiley‐VCH GmbH.)

Bioengineering strategies for the fabrication of implantable lymphoid structures mimicking lymph nodes (LNs) and tertiary lymphoid structures (TLS) could amplify the adaptive immune response for therapeutic applications such as cancer immunotherapy. No method to date has resulted in the consistent formation of high endothelial venules (HEVs), which is the specialized vasculature responsible for naïve T cell recruitment and education in both LNs and TLS. Here orthogonal induced differentiation of human pluripotent stem cells carrying a regulatable ETV2 allele is used to rapidly and efficiently induce endothelial differentiation. Assembly of embryoid bodies combining primitive inducible endothelial cells and primary human LN fibroblastic reticular cells results in the formation of HEV-like structures that can aggregate into 3D organoids (HEVOs). Upon transplantation into immunodeficient mice, HEVOs successfully engraft and form lymphatic structures that recruit both antigen-presenting cells and adoptively-transferred lymphocytes, therefore displaying basic TLS capabilities. The results further show that functionally, HEVOs can organize an immune response and promote anti-tumor activity by adoptively-transferred T lymphocytes. Collectively, the experimental approaches represent an innovative and scalable proof-of-concept strategy for the fabrication of bioengineered TLS that can be deployed in vivo to enhance adaptive immune responses., (© 2024 Wiley‐VCH GmbH.)

Wound healing in cases of excessive inflammation poses a significant challenge due to compromised neovascularization. Here, we propose a multi-functional composite hydrogel engineered to overcome such conditions through recruitment and activation of macrophages with adapted degradation of the hydrogel. The composite hydrogel (G-TSrP) is created by combining gelatin methacryloyl (GelMA) and nanoparticles (TSrP) composed of tannic acid (TA) and Sr 2+ . These nanoparticles are prepared using a one-step mineralization process assisted by metal-phenolic network formation. G-TSrP exhibits the ability to eliminate reactive oxygen species and direct polarization of macrophages toward M2 phenotype. It has been observed that the liberation of TA and Sr 2+ from G-TSrP actively facilitate the recruitment and up-regulation of the expression of extracellular matrix remodeling genes of macrophages, and thereby, coordinate in vivo adapted degradation of the G-TSrP. Most significantly, G-TSrP accelerates angiogenesis despite the TA's inhibitory properties, which are counteracted by the released Sr 2+ . Moreover, G-TSrP enhances wound closure under inflammation and promotes normal tissue formation with strong vessel growth. Genetic analysis confirms macrophage-mediated wound healing by the composite hydrogel. Collectively, these findings pave the way for the development of biomaterials that promote wound healing by creating regenerative environment., Competing Interests: None., (© 2024 The Authors.)

Skeletal muscle connective tissue (MCT) surrounds myofiber bundles to provide structural support, produce force transduction from tendons, and regulate satellite cell differentiation during muscle regeneration. Engineered muscle tissue composed of myofibers layered within MCT has not yet been developed. Herein, a bioengineering strategy to create MCT-layered myofibers through the development of stem cell fate-controlling biomaterials that achieve both myogenesis and fibroblast differentiation in a locally controlled manner at the single construct is introduced. The reciprocal role of transforming growth factor-beta 1 (TGF- β 1) and its inhibitor as well as 3D matrix stiffness to achieve co-differentiation of MCT fibroblasts and myofibers from a human-induced pluripotent stem cell (hiPSC)-derived paraxial mesoderm is studied. To avoid myogenic inhibition, TGF- β 1 is conjugated on the gelatin-based hydrogel to control the fibroblasts' populations locally; the TGF- β 1 degrades after 2 weeks, resulting in increased MCT-specific extracellular matrix (ECM) production. The locations of myofibers and fibroblasts are precisely controlled by using photolithography and co-axial wet spinning techniques, which results in the formation of MCT-layered functional myofibers in 3D constructs. This advanced engineering strategy is envisioned as a possible method for obtaining biomimetic human muscle grafts for various biomedical applications., Competing Interests: Conflict of Interest The authors declare no conflict of interest.

Background and Objective: By combining biomaterials, cell culture, and microfluidic technology, organ-on-a-chip (OoC) platforms have the ability to reproduce the physiological microenvironment of human organs. For this reason, these advanced microfluidic devices have been used to resemble various diseases and investigate novel treatments. In addition to the experimental assessment, numerical studies of biodevices have been performed aiming at their improvement and optimization. Despite considerable progress in numerical modeling of biodevices, the validation of these computational models through comparison with experimental assays remains a significant gap in the current literature. This step is critical to ensure the accuracy and reliability of numerical models, and consequently enhance confidence in their predictive results. The aim of the present work is to develop a numerical model capable of reproducing the fluid flow behavior within an OoC, for future investigations, encompassing the geometry optimization., Methods: In this study, the validation of a numerical model for an OoC microfluidic device was undertaken. This comprised both quantitative and qualitative assessments of trace microparticles flowing through a physical OoC model. High-speed microscopy images of the flow, using a blood analog fluid, were analyzed and compared with the numerical simulations run using the Ansys Fluent software. For a qualitative analysis, the particles' paths through the inlet and bifurcations were observed whereas, for a quantitative analysis, the particle velocities were measured. Furthermore, oxygen transport was simulated and evaluated for different Reynolds numbers., Results: In both qualitative and quantitative analyses, the results predicted by the numerical model and the ones outputted by the experimental model were in good agreement. These findings underscore the capability and potential of the developed numerical model. The examination of oxygen transport at various vertical positions within the organoid has revealed that for lower positions, oxygen transport predominantly occurs through diffusion, leading to a symmetric distribution of oxygen. Contrastingly, the convection phenomenon becomes more evident in the upper region of the organoid., Conclusions: The successful validation of the numerical model against experimental data shows its accuracy and reliability in simulating the fluid flow within the OoC, which consequently can expedite the OoC design process by reducing the need for prototypes' fabrication and costly laboratory experiments., 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 © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Nephrons are generally not distributed in the head kidney of teleost. Nonetheless, in this study, the nephron structure was identified in the head kidney of three species of Sebastes (Sebastes inermis, Sebastes schlegelii and Sebastes thompsoni). The kidney is Y shaped, with the development in the head kidney. The nephron structure was confirmed in the head kidney and body kidney. In addition, the nephron consisted of renal corpuscles and tubules, and the renal corpuscle consisted of the Bowman's capsule and glomerulus. Histologically, previous studies reported that the nephron structure is similar to that of other marine teleost. The renal tubule is a simple columnar epithelial layer with microvilli and cilia on the free surface, which is observed as a brush border. The Rrk (relative area ratio of kidney to body surface) was 5.14%, 7.58% and 5.17% in S. inermis, S. schlegelii and S. thompsoni, respectively. The Gar (glomerular area ratio of the head kidney) was higher in the central area than in the peripheral area, and species, which showed significant difference (P < 0.05), were in the following order: S. thompsoni (1.60%) > S. schlegelii (0.90%) > S. inermis (0.66%)., (© 2023 Fisheries Society of the British Isles.)

Injectable hydrogels based on natural polymers have shown great potential for various tissue engineering applications, such as wound healing. However, poor mechanical properties and weak self-healing ability are still major challenges. In this work, we introduce a host-guest (HG) supramolecular interaction between acrylate-β-cyclodextrin (Ac-β-CD) conjugated on methacrylated kappa-carrageenan (MA-κ-CA) and aromatic residues on gelatin to provide self-healing characteristics. We synthesize an MA-κ-CA to conjugate Ac-β-CD and fabricate dual crosslinked hybrid hydrogels with gelatin to mimic the native extracellular matrix (ECM). The dual crosslinking occurs on the MA-κ-CA backbone through the addition of KCl and photocrosslinking process, which enhances mechanical strength and stability. The hybrid hydrogels exhibit shear-thinning, self-healing, and injectable behavior, which apply easily under a minimally invasive manner and contribute to shear stress during the injection. In-vitro studies indicate enhanced cell viability. Furthermore, scratch assays are performed to examine cell migration and cell-cell interaction. It is envisioned that the combination of self-healing and injectable dual crosslinked hybrid hydrogels with HG interactions display a promising and functional biomaterial platform for wound healing applications., (© 2023 Wiley Periodicals LLC.)

Engineered three-dimensional (3D) tissue constructs have emerged as a promising solution for regenerating damaged muscle tissue resulting from traumatic or surgical events. 3D architecture and function of the muscle tissue constructs can be customized by selecting types of biomaterials and cells that can be engineered with desired shapes and sizes through various nano- and micro-fabrication techniques. Despite significant progress in this field, further research is needed to improve, in terms of biomaterials properties and fabrication techniques, the resemblance of function and complex architecture of engineered constructs to native muscle tissues, potentially enhancing muscle tissue regeneration and restoring muscle function. In this review, we discuss the latest trends in using nano-biomaterials and advanced nano-/micro-fabrication techniques for creating 3D muscle tissue constructs and their regeneration ability. Current challenges and potential solutions are highlighted, and we discuss the implications and opportunities of a future perspective in the field, including the possibility for creating personalized and biomanufacturable platforms., (© 2023. Korea Nanotechnology Research Society (KoNTRS).)

This is a quasi-experimental study applying a nonequivalent control group pre-test-post-test design with the control of exogenous variables to compare the research variables among experimental groups. Participants totaled 67 and were divided into three groups, each participating in a different training program (lecture, online video, and case-based peer role-play). There were significant increases in attitudes toward smoking cessation interventions in Experiment 2 (online video) (t = -2.48, p = .021) and Experiment 3 (case-based peer role-play) (t = -2.69. p = .013), efficacy of smoking cessation interventions in Experiment 2 (-2.06, p = .052), and intention to deliver smoking cessation intervention in all experimental groups (Exp 1 t = -5.54, p < .001; Exp 2 t = -2.83, p = .010; Exp 3 t = -3.50, p = .002). All three programs of smoking cessation counseling education (lecture, online video, and case-based peer role-play) used in this study showed meaningful results on the study variables. In conclusion, all of the approaches of this study were found to be effective on the intention to deliver smoking cessation intervention, and it is important to creatively apply counseling programs that include essential elements of smoking cessation interventions in nursing education settings.

Oxygenating biomaterials can alleviate anoxic stress, stimulate vascularization, and improve engraftment of cellularized implants. However, the effects of oxygen-generating materials on tissue formation have remained largely unknown. Here, we investigate the impact of calcium peroxide (CPO)-based oxygen-generating microparticles (OMPs) on the osteogenic fate of human mesenchymal stem cells (hMSCs) under a severely oxygen deficient microenvironment. To this end, CPO is microencapsulated in polycaprolactone to generate OMPs with prolonged oxygen release. Gelatin methacryloyl (GelMA) hydrogels containing osteogenesis-inducing silicate nanoparticles (SNP hydrogels), OMPs (OMP hydrogels), or both SNP and OMP (SNP/OMP hydrogels) are engineered to comparatively study their effect on the osteogenic fate of hMSCs. OMP hydrogels associate with improved osteogenic differentiation under both normoxic and anoxic conditions. Bulk mRNAseq analyses suggest that OMP hydrogels under anoxia regulate osteogenic differentiation pathways more strongly than SNP/OMP or SNP hydrogels under either anoxia or normoxia. Subcutaneous implantations reveal a stronger host cell invasion in SNP hydrogels, resulting in increased vasculogenesis. Furthermore, time-dependent expression of different osteogenic factors reveals progressive differentiation of hMSCs in OMP, SNP, and SNP/OMP hydrogels. Our work demonstrates that endowing hydrogels with OMPs can induce, improve, and steer the formation of functional engineered living tissues, which holds potential for numerous biomedical applications, including tissue regeneration and organ replacement therapy., 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 © 2023 Elsevier Ltd. All rights reserved.)

Scaffolds are implants commonly used to deliver cells, drugs, and genes into the body. Their regular porous structure ensures the proper support for cell attachment, proliferation, differentiated function, and migration. Techniques to fabricate a scaffold include leaching, freeze-drying, supercritical fluid technology, thermally induced phase separation, rapid prototyping, powder compaction, sol-gel, and melt molding. Gene delivery from the scaffold represents a versatile approach to influence the environment for managing cell function. Scaffolds can be used for various tissue engineering purposes, e.g. bone formation, periodontal regeneration, cartilage development, artificial corneas, heart valves, tendon repair, or ligament replacement. Moreover, they are also instrumental in cancer therapy, inflammation, diabetes, heart disease, and wound dressings. Scaffolds provide a platform to extend the delivery of drugs and genetic materials at a controlled timeframe, besides potentially being used to prevent infection upon surgery and other chronic diseases, provided that they can be formulated with specific medicines. This review discusses the need to design advanced functional scaffolds with the potential for modified drug delivery and tissue engineering in a synergistic approach. Special attention is given to works published in 2023 to generate the bibliometric map., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

Chronic wounds in diabetic patients are challenging because their prolonged inflammation makes healing difficult, thus burdening patients, society, and health care systems. Customized dressing materials are needed to effectively treat such wounds that vary in shape and depth. The continuous development of 3D-printing technology along with artificial intelligence has increased the precision, versatility, and compatibility of various materials, thus providing the considerable potential to meet the abovementioned needs. Herein, functional 3D-printing inks comprising DNA from salmon sperm and DNA-induced biosilica inspired by marine sponges, are developed for the machine learning-based 3D-printing of wound dressings. The DNA and biomineralized silica are incorporated into hydrogel inks in a fast, facile manner. The 3D-printed wound dressing thus generates provided appropriate porosity, characterized by effective exudate and blood absorption at wound sites, and mechanical tunability indicated by good shape fidelity and printability during optimized 3D printing. Moreover, the DNA and biomineralized silica act as nanotherapeutics, enhancing the biological activity of the dressings in terms of reactive oxygen species scavenging, angiogenesis, and anti-inflammation activity, thereby accelerating acute and diabetic wound healing. These bioinspired 3D-printed hydrogels produce using a DNA-induced biomineralization strategy are an excellent functional platform for clinical applications in acute and chronic wound repair., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Human cortical organoids (hCOs), derived from human induced pluripotent stem cells (iPSCs), provide a platform to interrogate mechanisms of human brain development and diseases in complex three- dimensional tissues. However, current hCO development methods lack important non-neural tissues, such as the surrounding meningeal layer, that have been shown to be essential for normal corticogenesis and brain development. Here, we first generated hCOs from a single rosette to create more homogenous organoids with consistent size around 250 µm by day 5. We then took advantage of a 3D co-culture system to encapsulate brain organoids with a thin layer of meningeal cells from the very early stages of cortical development. Immunostaining analysis was performed to display different cortical layer markers during different stages of development. Real-time monitoring of organoid development using IncuCyte displayed enhanced morphology and increased growth rate over time. We found that meningeal-encapsulated organoids illustrated better laminar organization by exhibiting higher expression of REELIN by Cajal-Retzius neurons. Presence of meningeal cells resulted in a greater expansion of TBR2 intermediate progenitor cells (IPCs), the deep cortical layer (CTIP2) and upper cortical layer (BRN2). Finally, meningeal-encapsulated organoids enhanced outer radial glial and astrocyte formation illustrated by stronger expression of HOPX and GFAP markers, respectively. This study presents a novel 3D co-culture platform to more closely mimic the in vivo cortical brain structure and enable us to better investigating mechanisms underlying the neurodevelopmental disorders during embryonic development., (© 2023. The Author(s).)

Aim: The aim of the study was to determine the multiple potential contributing factors in preventive behaviours, including COVID-19 vaccination for an effective campaign strategy., Design: This is a descriptive correlation study to examine the effects of the behavioural outcome, attitude, subjective norm, perceived behavioural control, optimistic bias and social stigma on the intention of preventive behaviour, based on Ajen's Theory of Planned Behaviour., Methods: The survey was performed by a professional research company online from 16-19 July 2021. Two hundred and thirty-three participants who had not been vaccinated against COVID-19 at the time of data collection completed the survey., Results: Perceived benefit, perceived behavioural control and social stigma are significantly associated with intention of preventive behaviours. The factors engaging in preventive behaviour presents us that our society is strongly influenced by social groups. Social groups influence decision-making in intention of preventing behaviour. Public education using social networks can increase such desirable behaviour., (© 2023 The Authors. Nursing Open published by John Wiley & Sons Ltd.)

Developing bioelectronics that retains their long-term functionalities in the human body during daily activities is a current critical issue. To accomplish this, robust tissue adaptability and biointerfacing of bioelectronics should be achieved. Hydrogels have emerged as promising materials for bioelectronics that can softly adapt to and interface with tissues. However, hydrogels lack toughness, requisite electrical properties, and fabrication methodologies. Additionally, the water-swellable property of hydrogels weakens their mechanical properties. In this work, an intrinsically nonswellable multifunctional hydrogel exhibiting tissue-like moduli ranging from 10 to 100 kPa, toughness (400-873 J m -3 ), stretchability (≈1000% strain), and rapid self-healing ability (within 5 min), is developed. The incorporation of carboxyl- and hydroxyl-functionalized carbon nanotubes (fCNTs) ensures high conductivity of the hydrogel (≈40 S m -1 ), which can be maintained and recovered even after stretching or rupture. After a simple chemical modification, the hydrogel shows tissue-adhesive properties (≈50 kPa) against the target tissues. Moreover, the hydrogel can be 3D printed with a high resolution (≈100 µm) through heat treatment owing to its shear-thinning capacity, endowing it with fabrication versatility. The hydrogel is successfully applied to underwater electromyography (EMG) detection and ex vivo bladder expansion monitoring, demonstrating its potential for practical bioelectronics., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Purpose: This study aimed to evaluate the radiological and clinical characteristics of benign adenomyoepitheliomas of the breast., Materials and Methods: Over the last 20 years, 120 patients were histologically diagnosed with breast adenomyoepithelioma (AME) at our institution. We excluded 43 patients who were incidentally diagnosed during mastectomy for breast cancer, 28 who underwent percutaneous biopsy without further excision, and 8 who had biopsy-confirmed benign AME and were found to have another pathology after complete excision. We retrospectively reviewed the clinical records and radiological findings of the remaining 41 patients with histologically diagnosed benign breast AMEs after complete excision., Results: All 41 patients underwent US; 38 underwent mammography (MG) and US; and 18 underwent MG, US, and MRI. MG detected 38 cases with a round or oval shape (56%), and mass (89%), were non-circumscribed (62%), hyperdense (53%), and without microcalcifications (95%). Breast US revealed suspicious masses (98%) with a non-circumscribed margin (66%), hypoechogenicity (43%), and intratumoral vascularity (63%). All lesions on breast MRI showed suspicious masses (100%) with ill-defined margins (61%), and 84% showed wash-out kinetics. Benign AMEs showed suspicious features of Breast Imaging Reporting and Data System (BI-RADS) category 4 or 5 in 83%-95% of the MG, US, and MRI. Sixteen of the 41 cases were misdiagnosed on the initial core needle biopsy and two were diagnosed as malignancy., Conclusion: Benign breast AME often shows suspicious radiological features mimicking a malignant mass on MG, US, and MRI. Differentiating benign AME from other pathologies might be difficult on core needle biopsy, and complete excision is needed for a correct diagnosis., Competing Interests: Conflicts of Interest: The authors have no potential conflicts of interest to disclose., (Copyrights © 2023 The Korean Society of Radiology.)

Heart disease is the leading cause of death worldwide and imposes a significant burden on healthcare systems globally. A major hurdle to the development of more effective therapeutics is the reliance on animal models that fail to faithfully recapitulate human pathophysiology. The predictivity of in vitro models that lack the complexity of in vivo tissue remain poor as well. To combat these issues, researchers are developing organ-on-a-chip models of the heart that leverage the use of human induced pluripotent stem cell-derived cardiomyocytes in combination with novel platforms engineered to better recapitulate tissue- and organ-level physiology. The integration of novel biosensors into these platforms is also a critical step in the development of these models, as they allow for increased throughput, real-time and longitudinal phenotypic assessment, and improved efficiency during preclinical disease modeling and drug screening studies. These platforms hold great promise for both improving our understanding of heart disease as well as for screening potential therapeutics based on clinically relevant endpoints with better predictivity of clinical outcomes. In this review, we describe state-of-the-art heart-on-a-chip platforms, the integration of novel biosensors into these models for real-time and continual monitoring of tissue-level physiology, as well as their use for modeling heart disease and drug screening applications. We also discuss future perspectives and further advances required to enable clinical trials-on-a-chip and next-generation precision medicine platforms., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Deok-Ho Kim is a scientific founder and equity holder of Curi Bio. Deok-Ho Kim reports a relationship with Curi Bio that includes: board membership, consulting or advisory, equity or stocks, funding grants, and travel reimbursement., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Among the five members of the dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK) family, the cellular functions of DYRK3 have not been fully elucidated. Some studies have indicated limited physiological roles and substrates of DYRK3, including promotion of glioblastoma, requirement in influenza virus replication, and coupling of stress granule condensation with mammalian target of rapamycin complex 1 signaling. Here, we demonstrate that serum deprivation causes a decrease in intracellular DYRK3 levels via the proteolytic autophagy pathway, as well as the suppression of DYRK3 gene expression. To further demonstrate how DYRK3 affects cell viability, especially in neurons, we used a yeast two-hybrid assay and identified multiple DYRK3-binding proteins, including SNAPIN, a SNARE-associated protein implicated in synaptic transmission. We also found that DYRK3 directly phosphorylates SNAPIN at the threonine (Thr) 14 residue, increasing the interaction of SNAPIN with other proteins such as dynein and synaptotagmin-1. In central nervous system neurons, SNAPIN is associated with and mediate the retrograde axonal transport of diverse cellular products from the distal axon terminal to the soma and the synaptic release of neurotransmitters, respectively. Moreover, phosphorylation of SNAPIN at Thr-14 was found to positively modulate mitochondrial retrograde transport in mouse cortical neurons and the recycling pool size of synaptic vesicles, contributing to neuronal viability. In conclusion, the present study demonstrates that DYRK3 phosphorylates SNAPIN, positively regulating the dynein-mediated retrograde transport of mitochondria and SNARE complex-mediated exocytosis of synaptic vesicles within the neurons. This finding further suggests that DYRK3 affects cell viability and provides a novel neuroprotective mechanism., (© 2022. The Author(s).)

Recapitulating inherent heterogeneity and complex microarchitectures within confined print volumes for developing implantable constructs that could maintain their structure in vivo has remained challenging. Here, we present a combinational multimaterial and embedded bioprinting approach to fabricate complex tissue constructs that can be implanted postprinting and retain their three-dimensional (3D) shape in vivo . The microfluidics-based single nozzle printhead with computer-controlled pneumatic pressure valves enables laminar flow-based voxelation of up to seven individual bioinks with rapid switching between various bioinks that can solve alignment issues generated during switching multiple nozzles. To improve the spatial organization of various bioinks, printing fidelity with the z -direction, and printing speed, self-healing and biodegradable colloidal gels as support baths are introduced to build complex geometries. Furthermore, the colloidal gels provide suitable microenvironments like native extracellular matrices (ECMs) for achieving cell growths and fast host cell invasion via interconnected microporous networks in vitro and in vivo . Multicompartment microfibers ( i.e. , solid, core-shell, or donut shape), composed of two different bioink fractions with various lengths or their intravolume space filled by two, four, and six bioink fractions, are successfully printed in the ECM-like support bath. We also print various acellular complex geometries such as pyramids, spirals, and perfusable branched/linear vessels. Successful fabrication of vascularized liver and skeletal muscle tissue constructs show albumin secretion and bundled muscle mimic fibers, respectively. The interconnected microporous networks of colloidal gels result in maintaining printed complex geometries while enabling rapid cell infiltration, in vivo .

Heat stimulation can promote osteoblast differentiation and bone formation. Combining photothermal therapy and chemotherapy is an effective strategy for treating rheumatoid arthritis (RA). Herein, we prepared chitosan/gelatin/β-glycerophosphate-melanin-methotrexate (CMM) hydrogel that could be used to perform simultaneous chemotherapy and photothermal therapy for patients with RA. The CMM solution was successfully converted to a gel state at body temperature. Due to intrinsic photothermal properties of melanin, CMM hydrogel exhibited effective temperature increase both in vitro and in vivo with increasing time of near-infrared (NIR) laser irradiation. After NIR laser irradiation, 50 % of methotrexate was rapidly released from the hydrogel within 3 h. Its release rate showed an instantaneous increase with additional NIR laser irradiation. After CMM hydrogel was injected directly into the paw joint of each collagen-induced arthritis (CIA) mouse followed by irradiation with a NIR laser (808 nm, 0.5 W/cm 2 , 3 min), swelling and redness at the inflamed area were significantly alleviated at 14 days after treatment. Micro-CT analysis confirmed that treated joints of mice were similar to normal joints. Hence, CMM hydrogel could be used as an attractive RA therapeutic agent for simultaneous chemo-photothermal therapy., (Copyright © 2022. Published by Elsevier B.V.)

To understand the habitat ecology of Tresus keenae, an infaunal bivalve, the microanatomical structure of the siphon and the method of siphonal sheath formation were described. The diameter of the incurrent siphon was approximately 1.2 times greater than that of the excurrent siphon. Several irregular tentacles developed inside the distal end of the siphon. The tentacles in the incurrent siphon were approximately twice as long as those in the excurrent siphon. The siphon consisted of six tissue layers, which, from the outside inward, were the siphonal sheath, matrix, outer epithelial layer, connective tissue layer, muscular layer, and inner epithelial layer. The siphonal sheath was composed of an outer cuticle and dense microfilament layer and had vertical ducts. The matrix showed a loose microfilament layer. The outer epithelial layer was simple consisting of ciliated columnar epithelia and secretory cells. There were two types of secretory cells: arenophilic cells and proteinous granular cells. These were all unicellular glands, with cytoplasmic projections developing on the free surface and microstructural features of the cytoplasm showing secretory activity. Histochemical analysis indicated that the secretory granules of the secretory cells, the dense microfilament layer, and the matrix were composed of neutral carboxylated mucopolysaccharides. From these characteristics, it was concluded that the siphonal sheath was formed via the transportation of substances secreted by secretory cells of the outer epithelial layer to the outside through the duct. The hemolymph sinus developed in the connective tissue layer. The muscular layer had alternating longitudinal and circular muscle layers. The inner epithelial layer was simple and consisted of ciliated columnar epithelial cells and secretory cells. Secretory cells are goblet-like cells and contain acidic carboxylated substances. The siphonal sheath was identified starting at approximately 3.5 mm in shell length before the infaunal stage; as it grew, the siphonal sheath thickened, reflecting the infaunal habitat., 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 © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In additive manufacturing, bioink formulations govern strategies to engineer 3D living tissues that mimic the complex architectures and functions of native tissues for successful tissue regeneration. Conventional 3D-printed tissues are limited in their ability to alter the fate of laden cells. Specifically, the efficient delivery of gene expression regulators (i.e. microRNAs (miRNAs)) to cells in bioprinted tissues has remained largely elusive. In this study, we explored the inclusion of extracellular vesicles (EVs), naturally occurring nanovesicles (NVs), into bioinks to resolve this challenge. EVs show excellent biocompatibility, rapid endocytosis, and low immunogenicity, which lead to the efficient delivery of miRNAs without measurable cytotoxicity. EVs were fused with liposomes to prolong and control their release by altering their physical interaction with the bioink. Hybrid EVs-liposome (hEL) NVs were embedded in gelatin-based hydrogels to create bioinks that could efficiently encapsulate and deliver miRNAs at the target site in a controlled and sustained manner. The regulation of cells' gene expression in a 3D bioprinted matrix was achieved using the hELs-laden bioink as a precursor for excellent shape fidelity and high cell viability constructs. Novel regulatory factors-loaded bioinks will expedite the translation of new bioprinting applications in the tissue engineering field., (© 2022 IOP Publishing Ltd.)