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The field of tissue engineering has made significant advancements with extrusion-based bioprinting, which uses shear forces to create intricate tissue structures. However, the success of this method heavily relies on the rheological properties of bioinks. Most bioinks use shear-thinning. While a few component-based efforts have been reported to predict the viscosity of bioinks, the impact of shear rate has been vastly ignored. To address this gap, our research presents predictive models using machine learning (ML) algorithms, including polynomial fit (PF), decision tree (DT), and random forest (RF), to estimate bioink viscosity based on component weights and shear rate. We utilized novel bioinks composed of varying percentages of alginate (2–5.25%), gelatin (2–5.25%), and TEMPO-Nano fibrillated cellulose (0.5–1%) at shear rates from 0.1 to 100 s−1. Our study analyzed 169 rheological measurements using 80% training and 20% validation data. The results, based on the coefficient of determination (R2) and mean absolute error (MAE), showed that the RF algorithm-based model performed best: [(R2, MAE) RF = (0.99, 0.09), (R2, MAE) PF = (0.95, 0.28), (R2, MAE) DT = (0.98, 0.13)]. These predictive models serve as valuable tools for bioink formulation optimization, allowing researchers to determine effective viscosities without extensive experimental trials to accelerate tissue engineering. [ABSTRACT FROM AUTHOR]

Sustainable hybrid composites, made of two different natural plant fiber types, are increasingly being attracted by composite researchers, for their cost effectiveness and ability to control mechanical performances through varying weight ratios of different fibers. In contrast, their lower mechanical properties are reported in the literature, because of strength variations of different fiber types and an improper fiber‐matrix stress distribution. Therefore, it is aimed to develop sustainable hybrid composites from two dry fiber preforms—woven fabric and short fiber preform—originated from same fiber type (jute). A highly packed short fiber preform is used as the core layer, while woven fabrics (plain/twill–rib/twill–diamond) are used in the skin layers for producing sandwiched hybrid jute composites. Mechanical tests and scanning electron microscopy images show that hybridized plain fabric/short fiber preform composites have better mechanical properties (≈58 MPa tensile strength/≈117 MPa flexural strength/≈112.12 kJm−2 impact strength with an ≈487.4% improvement) compared to other fabric structures hybrid/nonhybrid composites. This enhancement is related to the interlocking of short fibers with long plain fabric leading to a strong fiber‐matrix interfacial bonding. Thus, this developed hybrid composites, can be applied in many semi‐structural applications, wherein composites' low cost and mechanical performances are primary concerns. [ABSTRACT FROM AUTHOR]

The rapid advancement of 3D bioprinting has created a need for cost-effective and versatile 3D printers capable of handling bio-inks at various scales. This study introduces a novel framework for a specialized nozzle-holding device designed for an extrusion-based 3D bioprinter, specifically tailored to address the rigorous requirements of tissue engineering applications. The proposed system combines a pneumatically actuated plunger mechanism with an adaptive nozzle system, ensuring the safe inhibition and precise dispensing of bio-inks. Rigorous thermal management strategies are employed to maintain consistently low temperatures, thereby preserving bio-ink integrity without changing chemical stability. A key component of this design is a precision-milled aluminum block, which optimizes thermal characteristics while providing a protective barrier. Additionally, a 3D-printed extruder head bracket, fabricated using a high-precision resin printer, effectively mitigates potential thermal inconsistencies. The integration of these meticulously engineered components results in a modified extrusion-based 3D bioprinter with the potential to significantly advance tissue engineering methodologies. This study not only contributes to the advancement of bioprinting technology but also underscores the crucial role of innovative engineering in addressing tissue engineering challenges. The proposed bioprinter design lays a solid foundation for future research, aiming to develop more accurate, efficient, and reliable bioprinting solutions. [ABSTRACT FROM AUTHOR]

This study explored extrusion-based 3D bioprinting as a method for depositing cell-laden bio-ink to create well-defined scaffolds for tissue regeneration. Natural hydrogels, known for their biocompatibility and low cell toxicity, were favored for bio-ink formulation in this process. However, their limited mechanical strength poses a challenge to maintaining structural integrity. To address this, the rheological properties of hybrid hydrogels containing cellulose-derived nanofiber (TONFC) at concentrations between 0.5% and 1.0%, along with alginate and gelatin at levels between 2% and 5%, were tested in this study. A total of eight formulations was created by adjusting the proportions of alginate, TO-NFC, and gelatin, resulting in a combined solid content of 8%. Various rheological properties, such as the flow behavior, recovery rate, and linear viscoelastic range, were analyzed. Bi-layer scaffolds were 3D printed with various compositions and the shape fidelity was investigated. Human mesenchymal stem cells (hMSCs) were mixed to prepare bio-ink and cell survivability was observed after 7 incubation days. The ability to control 3D printability and the favorable survival of cells make nanofiber-infused alginate–gelatin a promising option for creating precisely shaped scaffolds using the 3D bio-printing process. [ABSTRACT FROM AUTHOR]

Groupers are among the fish groups that are difficult to recognize due to their high morphological similarities. Therefore, molecular techniques, particularly DNA barcoding, are extensively utilized to differentiate this fish group. This study aimed to analyze and validate six grouper species belonging to the Epinephelidae family that were harvested from Langsa district waters in Aceh province, Indonesia, based on DNA barcode data. It was conducted from June to December 2021, with the fish specimens collected from fishers at fish landing sites and the fish market in Langsa City, Aceh province. A total of 22 grouper sequences belonging to six species were generated, namely Epinephelus coioides, E. bleekeri, E. malabaricus, E. erythrurus, E. sexfasciatus and Mycteroperca poecilonotus (formerly Epinephelus poecilonotus). Genetic distance within these species ranged from 0.10 to 0.73% (average: 0.40%). Notably, E. malabaricus and E. coioides exhibited the closest genetic kinship (4.07%), while E. sexfasciatus and M. poecilonotus displayed the greatest genetic distance (19.33%). This study provides the first DNA reference for grouper in Langsa district, Indonesia, with significant implications for future sustainable grouper management. [ABSTRACT FROM AUTHOR]

This editorial discusses the impact of climate change on aquatic organisms, focusing on their ecology, diversity, and migration patterns. The Intergovernmental Panel on Climate Change (IPCC) reports that climate change is a significant threat to global biodiversity, and aquatic species are expected to shift their habitats in response to climate changes. The rise in temperature negatively affects marine species' performance and survival, and climate change also has unpredictable impacts on freshwater resources. The editorial highlights the importance of understanding these impacts and provides insights into specific topics such as siphonophores, odour-producing microorganisms, and the vulnerability of coral reefs. The authors emphasize the need for further research and conservation efforts to mitigate the effects of climate change on aquatic ecosystems. [Extracted from the article]