The vascular system exhibits complex, non-planar geometries that become further distorted during pathological remodeling, including arterial tortuosity and aneurysms. Although hemodynamic shear stress is a well-established regulator of vascular function, the direct effects of curvature as an intrinsic geometric cue remain poorly defined. This is largely because existing in vitro models are static and fail to capture the dynamic changes that accompany disease progression. To address this gap, we used a magnetoactive hydrogel platform that enables real-time, on-demand curvature of endothelial monolayers to reproduce clinically established tortuosity metrics. Using this system, we found that elevated curvature increased nuclear localization of yes-associated protein (YAP), with the strongest response in convex relative to concave regions of highly tortuous endothelial monolayers. This mechanosensitive response was accompanied by reduced VE-Cadherin junctional thickness and increased membrane localization of endothelial nitric oxide synthase. Together, these findings identify local curvature, independent of shear stress, as a regulator of endothelial cell mechanosensing and function, and establish a dynamic hydrogel platform for isolating geometric regulation from shear stress inputs in vascular mechanobiology.

The endometrium, the mucosal lining of the uterus, is a highly regenerative tissue that undergoes cyclic remodeling guided by tightly regulated levels of estrogen and progesterone. Stromal cells, including fibroblasts, are embedded within the connective tissue of the endometrium and contribute to the rapidly changing extracellular matrix (ECM). During the secretory phase, high levels of progesterone induce decidualization of endometrial fibroblasts, which changes their morphology and protein secretion. While it has been shown that the mechanical properties of endometrial tissue, such as the elastic modulus, also contribute to tissue homeostasis and pathology, the interplay between hormones and tissue modulus in contributing to ECM remodeling remains unknown. To address this, we used hydrogels of varying elastic moduli (5 and 15 kPa) to induce decidualization of endometrial fibroblasts. Using metabolic labeling of glycosylated nascent ECM proteins, we then visualized and measured the deposition of newly secreted (nascent) ECM proteins during decidualization. In addition, we designed an automated ImageJ-based workflow for unbiased quantification of nascent ECM deposition. Our results demonstrate that both 5 and 15 kPa hydrogels support decidualization of endometrial stromal fibroblasts as shown by an increase in cell flattening and prolactin secretion. While increased hydrogel modulus alone enhances nascent ECM deposition, decidualization produces an additional increase that converges to similar levels regardless of the initial hydrogel modulus. Collectively, these findings demonstrate that endometrial stromal fibroblasts deposit nascent ECM that is enhanced during decidualization. These observations may provide new insights toward future studies addressing the mechanisms of ECM remodeling in endometrial tissue.

Within most tissues, the extracellular microenvironment provides mechanical cues that guide cell fate and function. Changes in the extracellular matrix such as aberrant deposition, densification and increased crosslinking are hallmarks of late-stage fibrotic diseases that often lead to organ dysfunction. Biomaterials have been widely used to mimic the mechanical properties of the fibrotic matrix and study pathophysiologic cell function. However, the initiation of fibrosis has largely been overlooked, due to challenges in recapitulating early stages of disease progression within the native extracellular microenvironment. Here, using visible-light-mediated photochemistry, we induced local crosslinking and stiffening of extracellular matrix proteins within ex vivo mouse and human lung tissue. In ex vivo lung tissue of epithelial cell lineage-traced mice, local matrix crosslinking mimicked early fibrotic lesions that increased alveolar epithelial cell mechanosensing, differentiation, and nascent protein deposition and remodelling. However, the inhibition of cytoskeletal tension, mechanosensitive signalling pathways or integrin engagement reduced epithelial cell spreading and differentiation. Our findings emphasize the role of local extracellular matrix crosslinking and nascent protein deposition in early stage tissue fibrosis and have implications for ex vivo disease modelling and applications to other tissues.

Polymeric hydrogels are valuable platforms for determining how specific mechanical properties of native tissue extracellular matrix (ECM) regulate cell function. Recent research has focused on incorporating viscous and elastic properties into hydrogels to investigate cellular responses to time-dependent mechanical properties of the ECM. However, a critical aspect is that cells continuously remodel their microenvironment in hydrogels, such as by the deposition of newly secreted (nascent) ECM. While this nascent ECM has been demonstrated to play a vital role in transmitting mechanical signals across various biological contexts, the mechanisms by which it regulates cellular function in response to time-dependent mechanical properties remain poorly understood. In this study, we developed an interpenetrating polymer network that enables independent control of viscous and elastic hydrogel properties. We show that cells cultured on high-viscosity hydrogels deposit increased nascent ECM, which also correlates with enhanced hydrogel remodeling. Interestingly, higher nascent ECM deposition on high-viscosity hydrogels was decoupled from intracellular contractility. These results establish a relationship between hydrogel viscosity and nascent ECM deposition that may extend to diverse cell types and offer new insights into cell-hydrogel interactions.

Introduction Mechanical forces provide critical biological signals to cells. Within the distal lung, tensile forces act across the basement membrane and epithelial cells atop. Stretching devices have supported studies of mechanical forces in distal lung epithelium to gain mechanistic insights into pulmonary diseases. However, the integration of curvature into devices applying mechanical forces onto lung epithelial cell monolayers has remained challenging. To address this, we developed a hammock-shaped platform that offers desired curvature and mechanical forces to lung epithelial monolayers. Methods We developed hammocks using polyethylene terephthalate (PET)-based membranes and magnetic-particle modified silicone elastomer films within a 48-well plate that mimic the alveolar curvature and tensile forces during breathing. These hammocks were engineered and characterized for mechanical and cell-adhesive properties to facilitate cell culture. Using human small airway epithelial cells (SAECs), we measured monolayer formation and mechanosensing using F-Actin staining and immunofluorescence for cytokeratin to visualize intermediate filaments. Results We demonstrate a multi-functional design that facilitates a range of curvatures along with the incorporation of magnetic elements for dynamic actuation to induce mechanical forces. Using this system, we then showed that SAECs remain viable, proliferate, and form an epithelial cell monolayer across the entire hammock. By further applying mechanical stimulation via magnetic actuation, we observed an increase in proliferation and strengthening of the cytoskeleton, suggesting an increase in mechanosensing. Conclusion This hammock strategy provides an easily accessible and tunable cell culture platform for mimicking distal lung mechanical forces in vitro. We anticipate the promise of this culture platform for mechanistic studies, multi-modal stimulation, and drug or small molecule testing, extendable to other cell types and organ systems.

The extracellular matrix (ECM) of the tissue organ exhibits a topography from the nano to micrometer range, and the design of scaffolds has been inspired by the host environment. Modern bioprinting aims to replicate the host tissue environment to mimic the native physiological functions. A detailed discussion on the topographical features controlling cell attachment, proliferation, migration, differentiation, and the effect of geometrical design on the wettability and mechanical properties of the scaffold are presented in this review. Moreover, geometrical pattern-mediated stiffness and pore arrangement variations for guiding cell functions have also been discussed. This review also covers the application of designed patterns, gradients, or topographic modulation on 3D bioprinted structures in fabricating the anisotropic features. Finally, this review accounts for the tissue-specific requirements that can be adopted for topography-motivated enhancement of cellular functions during the fabrication process with a special thrust on bioprinting.

The importance of dynamic mechanical control over the cellular microenvironment has long been appreciated. In a recent issue of Device, Raman and colleagues design a clever yet generalizable tool to achieve this, illustrating magnetic stimulation of an engineered extracellular matrix to induce muscle fiber alignment toward programmed functioning.

Countless research has suggested Yttria-stabilized Zirconia (YSZ) to be a top candidate for being implemented as thermal barrier coatings (TBC). However, when exposed to prolonged service, temperature and stress variations succeed in initiating a catastrophic phase transformation from tetragonal to monoclinic structure in Zirconia. Hence, the estimation of endurance for YSZ-based TBC is necessary to minimize failure in such situations. The main purpose of this research was to determine the relationship between tribological investigations and the estimated lifespan of YSZ coatings accurately. The study used various methods such as wear resistance testing, optical profilometry, specific wear rate, and coefficient of friction to estimate the maximum durability of TBCs. The research also provided insights into the composition and microstructure of the TBC system and found the optimized concentration of Yttrium doping to be 3.5 wt %. The study discovered that erosion was the main cause of roughness depreciation from SN to S1000. The estimation of the service life was primarily made based on optical profilometry, specific wear rate (SWR), coefficient of friction (COF) and wear resistance values which were further supported by the results of chemical characterization of the samples through electron dispersive spectroscopy (EDS), wavelength dispersive spectroscopy (WDS) and X-Ray Diffraction (XRD) analysis. The results were reliable and accurate and suggested future areas of investigation, such as 3D profilometry for surface roughness and thermal conductivity evaluation using laser-assisted infrared thermometers.

Folding of mucosal tissues, such as the tissue within the epithelium of the upper respiratory airways, is critical for organ function. Studying the influence of folded tissue patterns on cellular function is challenging mainly due to the lack of suitable cell culture platforms that can recreate dynamic tissue folding in vitro. Here, a bilayer hydrogel folding system, composed of alginate/polyacrylamide double-network (DN) and hyaluronic acid (HA) hydrogels, to generate static folding patterns based on mechanical instabilities, is described. By encapsulating human fibroblasts into patterned HA hydrogels, human bronchial epithelial cells form a folded pseudostratified monolayer. Using magnetic microparticles, DN hydrogels reversibly fold into pre-defined patterns and enable programmable on-demand folding of cell-laden hydrogel systems upon applying a magnetic field. This hydrogel construction provides a dynamic culture system for mimicking tissue folding in vitro, which is extendable to other cell types and organ systems.

Hybrid plastics generally consist of an organic‐inorganic network, which is primarily used in the field of electronics. Polyhedral oligomeric silsesquioxane (POSS), an organic‐inorganic network, is a widely used hybrid plastic that acts as a molecular reinforcement to the polymer and improves its mechanical strength owing to its three-dimensional cage-like structure. This chapter also comprises a brief description of the novel plastic-metal hybrids and their interlocking stability for high-end applications. The current discussion also summarizes hybrid polymer composites and their modified mechanical properties to impart value addition. In this context, readers also get a clear idea about the difference between rubber, plastic, and fibers and plastics classification. Over the decades, the degradation problems with conventional plastics and growing concern for mitigating its associated environmental pollution have led researchers to develop biodegradable plastics. Primarily, Polybutylene succinates, Polylcaprolactone, Polyethylene succinate, Polybutyrate adipate terephthalate, etc. are some synthetic polymers. Simultaneously, Polyhydroxyalkanoate, polylactide, poly(hydroxybutyrate), etc. are common semi-synthetic biopolymer that has been aggressively used for fabrication of such bioplastics. This semi-synthetic material can be synthesized from several microalgal systems. However, the associated cost is a serious concern, and agricultural wastes, starch, cellulose esters, soy-based plastic, etc. are commonly used natural materials used for the fabrication of bioplastics. A brief overview of plastic and polymer composite fabrication methodologies has been provided additionally. A brief note on natural materials and their application for injecting sustainability has also been provided.

This chapter discusses mechanical properties such as strength, toughness, fracture mechanism, and deformation behavior of well-understood crystalline and semicrystalline polymer systems. Due to the complex shape of crystalline and semicrystalline polymer systems, sometimes it becomes challenging to explain the behavior of these polymers. The molecular theory also helps to explain the mechanical behavior of polymer to some extent. The sharp melting point of crystalline and semicrystalline polymer makes them challenging to thermoform. These materials are anisotropic inflow, so they shrink in the direction transverse to the flow than they do along the flow direction. It results in dimension instability. The strong intermolecular forces in the chain cause the formation of tough plastics, which perform exceptionally well in applications involving wear, bearing, and structural loads. Crystalline and Semicrystalline polymer exhibit organized and tightly packed molecular chains for which the mechanical behavior of those materials becomes very rigid and stiff compared to other polymer systems. Apart from that, the chapter provides insights on liquid crystalline polymer systems and bioinspired polymeric materials. Further, the chapter has encompassed the strengthening mechanism of polymer composite systems involving the role of an interface and the effect of nanoparticle addition with their size and concentration variation.

Magnetron sputtering has been one of the significant processes for developing defect-free uniform coatings for a wide range of materials. Increasing Magnesium (Mg) content in Aluminium (Al)-Mg sputtered coats has been strongly linked to a heightened sacrificial nature. This has directed researchers towards investigating different combinations or compositions of Al-based coats. Sputtered Al coats having minute proportions of Zinc (Zn) and Mg could be promising in terms of offering a corrosion-resistant coating on steel substrates. This has prompted a detailed analysis of three different coatings deposited on 4130 grade IF steel substrates using pure Al, Al-Mg and Al-Zn-Mg as targets by magnetron sputtering. For a fixed deposition time of 10 h, thickness of the coatings were in the order: Al-Zn-Mg > Al > Al-Mg. The coatings were investigated in terms of the microstructure, corrosion behaviour, surface roughness and coating adhesiveness. XRD was conducted to study the evolution of phases with increasing coating thickness. Al-Zn-Mg coating was found to be the most durable one, in terms of corrosion resistance, through EIS and SST and role of surface roughness was identified as a critical controlling factor, which was outweighed by the coating compositions. Although this ternary coating exhibited unsatisfactory performance during bend test, it has been hypothesized that tailoring texture coefficients could be a promising way to attain an optimum combination of oxidation resistance and adhesion.

For the past few decades, the use of Lithium (Li)-ion batteries (LIBs) has been extensive in the automotive and the consumer electronics industry and it will continue to dominate in the future too. Chronological development of electrode materials for LIBs has managed to finally boost behind the applications of LIBs. Nevertheless, more essential is the development of electrolytes. Through this article, readers shall be able to formulate a brief idea of several electrolytes and their drawbacks, along with reviews of polymer-ceramic composite electrolytes, including their acceptance based on three main critical issues: room temperature conductivity, transport number, and interfacial stability (interfacial reactions of electrode-electrolyte). The future application of LIBs in consumer electronics, automotive fields, and other areas mainly depends on the ongoing research and development of polymer-ceramic composite electrolytes. This article also lends much-needed attention to the addition of ceramic phases in the polymer matrix leading to increased transport number, augmented conductivity, and reduced interfacial reactions between electrode-electrolyte.

The use of Al-Mg-Si alloys has increased significantly in automobile and aerospace industries during the past few decades, and improving the formability of the alloy has always been under focus for various applications. Plane strain compression (PSC) tests have been conducted for EN AW 6016 naturally aged (T4) alloy at different temperatures (room temperature, 150 degrees C and 250 degrees C), at a particular strain rate (0.1 s(-1)). The samples exhibited a decreasing pattern of flow properties (yield strength and work hardening rate) and increasing anisotropy with temperature. The reasons for the changes in flow behaviour with temperature were explained with the help of finite element modelling (FEM). Work hardening behaviour at different stages of stress was investigated and correlated with the microstructure. Microstructural characterization has been performed using electron back-scattered diffraction (EBSD), and scanning electron microscopy (SEM) based Gallium Enhanced Microscopy (GEM) techniques with an aim to reveal the substructure development due to imposed deformation at different temperatures. Calculation of macro-texture was performed using X-Ray Diffraction (XRD) technique in order to observe the changes in crystallographic texture before and after deformation. A mathematical comparative analysis indicates the contribution of different texture components towards the variation in flow properties. Considerable increment in volume fraction of Goss texture at 250 degrees C has been found to have a significant impact on formability.

Three-dimensional (3D) bioprinting is an emerging tissue engineering approach that aims to develop cell or biomolecule-laden, complex polymeric scaffolds with high precision, using hydrogel-based "bioinks". Hydrogels are water-swollen, highly crosslinked polymer networks that are soft, quasi-solid, and can support and protect biological materials. However, traditional hydrogels have weak mechanical properties and cannot retain complex structures. They must be reinforced with physical and chemical manipulations to produce a mechanically resilient bioink. Over the past few years, we have witnessed an increased use of nanoparticles and biological moiety-functionalized nanoparticles to fabricate new bioinks. Nanoparticles of varied size, shape, and surface chemistries can provide a unique solution to this problem primarily because of three reasons: (a) nanoparticles can mechanically reinforce hydrogels through physical and chemical interactions. This can favorably influence the bioink's 3D printability and structural integrity by modulating its rheological, biomechanical, and biochemical properties, allowing greater flexibility to print a wide range of structures; (b) nanoparticles can introduce new bio-functionalities to the hydrogels, which is a key metric of a bioink's performance, influencing both cell-material and cell-cell interactions within the hydrogel; (c) nanoparticles can impart "smart" features to the bioink, making the tissue constructs responsive to external stimuli. Responsiveness of the hydrogel to magnetic field, electric field, pH changes, and near-infrared light can be made possible by the incorporation of nanoparticles. Additionally, bioink polymeric networks with nanoparticles can undergo advanced chemical crosslinking, allowing greater flexibility to print structures with varied biomechanical properties. Taken together, the unique properties of various nanoparticles can help bioprint intricate constructs, bringing the process one step closer to complex tissue structure and organ printing. In this review, we explore the design principles and multifunctional properties of various nanomaterials and nanocomposite hydrogels for potential, primarily extrusion-based bioprinting applications. We illustrate the significance of biocompatibility of the designed nanocomposite hydrogel-based bioink for clinical translation and discuss the different parameters that affect cell fate after cell-nanomaterial interaction. Finally, we critically assess the current challenges of nanoengineering bioinks and provide insight into the future directions of potential hydrogel bioinks in the rapidly evolving field of bioprinting.

Automotive products are one of the chief reasons for the smooth flow of modern civilization. But the adverse social, economic and environmental effects associated with automotive industries are the worries of scientists. Many significant steps have been taken by governments of various nations and leading research and development organizations of which most are to implement or enhance the renewable and sustainable measurements. This article intends to discuss how sustainable approaches in automobile industry can be beneficial to achieve the most advanced state without creating an adverse impact as well as how renewability serves as the key for green development. Various methods and ongoing applications have been given to incorporate renewability and sustainability. A comparative study between conventional and recently developed advanced materials has also been included. Finally, the article shows how recent technologies, like electric cars, can be made more commercially efficient and eco-friendly.

Cold spray is a promising technology that has attracted considerable attention in the field of coatings and additive manufacturing like intermetallics, metallic glasses, ceramics, and composites in recent years. It can deposit thick coatings with high deposition efficiency as compared to other thermal spraying techniques. It has got unique characteristics like low-temperature processing due to which no oxidation happens and microstructure of the coatings is the same as that of feedstock material. There has been much interest in research on the development of antimicrobial coatings with sustainable approaches within the past few decades. These cold sprayed coatings can be used for the prevention of transfer of bacteria from the contact surfaces to healthy people. In this article, a sketch of the strategic present and future perspective of bacteria resistant coatings on metals and polymer substrates using cold spray has been presented. The green aspects of this cold spray technique have also been highlighted.

In this review, few established cell printing techniques along with their parameters that affect the cell viability during bioprinting are considered. 3D bioprinting is developed on the principle of additive manufacturing using biomaterial inks and bioinks. Different bioprinting methods impose few challenges on cell printing such as shear stress, mechanical impact, heat, laser radiation, etc., which eventually lead to cell death. These factors also cause alteration of cells phenotype, recoverable or irrecoverable damages to the cells. Such challenges are not addressed in detail in the literature and scientific reports. Hence, this review presents a detailed discussion of several cellular bioprinting methods and their process-related impacts on cell viability, followed by probable mitigation techniques. Most of the printable bioinks encompass cells within hydrogel as scaffold material to avoid the direct exposure of the harsh printing environment on cells. However, the advantages of printing with scaffold-free cellular aggregates over cell-laden hydrogels have emerged very recently. Henceforth, optimal and favorable crosslinking mechanisms providing structural rigidity to the cell-laden printed constructs with ideal cell differentiation and proliferation, are discussed for improved understanding of cell printing methods for the future of organ printing and transplantation.