ACS Biomaterials Science & Engineering最新文献

This study explores the synergistic effects of combining titania nanotubes (TiNTs) with the biopolymer Tanfloc (TAN) to enhance the surface properties of TiNTs for biomedical applications. We investigated the interactions of blood components and human adipose-derived stem cells (ADSCs) with TiNT surfaces covalently functionalized with Tanfloc (TAN), an aminolyzed polyphenolic tannin derivative. The functionalized surfaces (TiNT-TAN) have great potential to control protein adsorption and platelet adhesion and activation. Fluorescence and scanning electron microscopy (SEM) were used to analyze platelet adherence and activation. The amphoteric nature and multiple functional groups on TAN can control blood protein adsorption, platelet adhesion, and activation. Further, the modified surface supports adipose-derived stem cell (ADSC) viability, attachment, and growth without any cytotoxic effect. The TAN conjugation significantly (****p < 0.0001) increased the proliferation rate of ADSCs compared to the TiNT surfaces.

In clinical practice, mini-screws of titanium-6-aluminum-4-vanadium alloy with an extra low interstitial (ELI) grade (Ti-6Al-4V ELI) are widely used as orthodontic anchorages. However, in orthodontic treatment, Ti-6Al-4V mini-screw failure because of peri-implantitis is a major challenge. To prevent damage caused by peri-implantitis, we developed a novel Ti-6Al-4V disc/screw coated with poly(lactide-co-glycolide) incorporating fisetin, a naturally occurring flavonoid with anti-inflammatory and antiosteoclastogenic/osteogenic properties. Sustained fisetin release from the Ti-6Al-4V disc and its anti-inflammatory and antiosteoclastogenic/osteogenic differentiation properties were demonstrated using in vitro cell culture experiment. In addition, in a rat model of peri-implantitis, sustained fisetin release from the Ti-6Al-4V screw suppressed inflammation progression, reduced alveolar bone resorption, and stabilized screw movement. These findings highlight sustained fisetin-release Ti-6Al-4V screws as a promising strategy for enhancing orthodontic mini-screw stability and success through peri-implantitis prevention.

This review explores the use of biogenic templates in nanomaterial synthesis, emphasizing their role in promoting environmentally sustainable nanotechnology. It categorizes various biogenic templates, including agricultural byproducts and microorganisms, stating their suitability for forming nanostructures due to their distinct properties. A comparative analysis of monostep and multistep synthesis methods is provided, focusing on their efficiencies and outcomes when using biogenic templates. Further, this review also highlights how these templates can generate complex nanostructures and hybrid materials with enhanced functionalities. Applications of biogenic templates across biomedicine, biotechnology, environmental science, and energy are discussed along with their utilization scope in agriculture and electronics. Benefits from nanostructures from biotemplates include sustainability, low cost, and reduced toxicity, but challenges like scalability, reproducibility, and regulatory compliance persist. Future research focuses on improving synthesis techniques, discovering new templates, and evaluating environmental and cytotoxic impacts, especially for biomedical uses. In conclusion, the review reaffirms the potential of biogenic templates in sustainable nanomaterial synthesis while highlighting the ongoing challenges that need to be addressed for broader adoption.

Sperm cryopreservation is important for many individuals across the globe. Recent studies show that vitrification is a valuable approach for maintaining sperm quality after freeze-thawing processes and requires sub-microliter to microliter volumes. A major challenge for the adoption of vitrification in fertility laboratories is the ability to pipet small volumes of sample. Here, we present an open droplet generator that leverages open-channel microfluidics to passively generate sub-microliter to microliter volumes of purified human sperm samples and preserves sperm kinematics. We conclude that our platform is compatible with human sperm, an important foundation for future implementation of vitrification in fertility laboratories.

There exists a significant correlation between the microstructural evolution and the mechanical properties of fibers during repeated loading and unloading cycles. Nevertheless, the influence of deformation and the duration of intervals on the structural and tensile behavior of spider silk after repeated stretching at a given strain value has been rarely reported, with the exception of studies focusing on the major ampullate gland silk (Mas) of the spider. In order to investigate the effects of repeated stretching on the structural and mechanical behavior of spider tubular gland silk (Tus), the tensile properties and the changes in semiquantitative protein secondary structure of Argiope bruennichi Tus during loading-unloading cycles were characterized. The results indicate that the typical tensile behavior curves of Tus were irreversibly modified to resemble those of Mas, demonstrating a clear yield region accompanied by a necking phenomenon. The Tus displays remarkable characteristics of repeated stretching and mechanical memory, and it is capable of reproducing the tensile behavior of fibers subjected to one stretch, independent from its previous loading history. The above phenomenon may be caused by repeated stretching leading to the damage and reconstruction of protein structures, including an increase in α-helix content and the rearrangement of spider-silk proteins, enabling them to reproduce their mechanical behavior. These findings may provide valuable insights for the biomimetic design of novel fiber materials, such as the spider silk gut, through the artificial stretching of spider silk glands.

The increasing prevalence of multidrug-resistant bacteria is a significant global health threat. In contrast to conventional antibiotic treatments, photodynamic therapy (PDT) offers a promising alternative by reducing the bacterial adaptability to antibiotics and bactericides. However, traditional photosensitizers encounter poor antimicrobial efficacy due to poor hydrophilicity of photosensitizers, short lifespan, narrow diffusion radius of reactive oxygen species (ROS), and the risk of exacerbating inflammation. In this study, we report a bacterial-targeting supramolecular nanophotosensitizer for combating multidrug resistant bacteria. The nanophotosensitizer, formed through host-guest interactions and self-assembly of tetra-cyclodextrin-modified silver porphyrin (AgTPP-CD₄), adamantyl-modified phenylboronic acid (Ad-PBA), and curcumin (Cur), can effectively target and kill methicillin-resistant Staphylococcus aureus (MRSA). Moreover, it reduces inflammation and promotes wound healing in MRSA-infected wounds without inducing drug resistance. The combination of supramolecular chemistry and targeted PDT offers a promising strategy for combating multidrug-resistant bacterial infections.

Traditional cancer research has long relied on two-dimensional (2D) cell cultures, which inadequately mimic the complex three-dimensional (3D) microenvironments of in vivo tumors. Recent advancements in 3D cell cultures, particularly cancer spheroids, have highlighted their superior physiological relevance. However, existing methods for spheroid generation often require complex, multistep fabrication processes that limit scalability and reproducibility. In this study, we present a novel single-step photolithographic technique to fabricate high-aspect-ratio V-slanted hydrogel microwells. By employing polyethylene glycol (PEG)-based hydrogels, we create biocompatible, extracellular matrix (ECM)-like scaffolds that enhance gas and nutrient exchange while promoting uniform spheroid formation. The hydrogel microwells allow precise control of spheroid size, achieving a physiologically relevant diameter of 425 μm within 12-24 h, and the resulting spheroids exhibiting high viability over 3 weeks. Moreover, the method facilitates the creation of scalable multiwell arrays for high-throughput applications, making it suitable for both small-scale and large-scale experimental needs. This platform addresses the limitations of traditional microwell fabrication, offering a robust, efficient, and reproducible system for generating physiologically relevant 3D models with valuable applications in cancer research, drug testing, and tissue engineering.

Infected diabetic wounds represent a significant challenge in clinical care due to persistent inflammation and impaired healing. To address these issues, the development of novel wound dressings with both antibacterial and reactive oxygen species (ROS) scavenging properties is essential. Herein, we prepare a novel wound dressing composed of Cu_2-xO nanoparticles decorated on Ti₃C₂ MXene (Cu_2-xO@Ti₃C₂) and integrate it into a poly(vinyl alcohol) (PVA) matrix to form electrospun nanofibers (Cu_2-xO@Ti₃C₂@PVA). Cu_2-xO@Ti₃C₂ exhibits remarkable photothermal conversion efficiency and effective ROS scavenging properties. In vitro experiments demonstrated that Cu_2-xO@Ti₃C₂ effectively kills bacteria upon near-infrared (NIR) irradiation, which can be attributed to the photothermal therapy (PTT) effect of Ti₃C₂. At the same time, the ROS scavenging abilities of both Ti₃C₂ and Cu_2-xO endow Cu_2-xO@Ti₃C₂ with significant in vitro anti-inflammatory effects. As a promising wound dressing, in vivo studies validated the high efficacy of Cu_2-xO@Ti₃C₂@PVA in promoting hemostasis, exerting antibacterial activity, reducing inflammation, and accelerating the healing process of diabetic wounds. This innovative approach provides a comprehensive solution to the multifaceted challenges of diabetic wound healing and paves the way for improved clinical outcomes.

Fibrocartilage decellularized extracellular matrix (dECM) is a promising alternative material for damaged fibrocartilage repair and replacement due to its biomimetic gross morphology and internal microstructure. However, the alterations in the microstructure and micromechanical properties of fibrocartilage after decellularization interfere with the macroscopic functional application of the scaffold. Therefore, this study aims to present an analytical atlas of the microstructure and micromechanics of the fibrocartilaginous dECM scaffold to elucidate the effect of decellularization treatment on the macroscopic function of the scaffold. The fibrocartilage dECM was prepared using the temporomandibular joint (TMJ) disc as the model, and its durability was evaluated under three functional states (physiological, physiological limit, and beyond the limit). The macroscopic function of different fibrocartilage dECM exhibits notable differences, which are attributed to the destruction of the multilevel collagen structure. This process involves unwinding triple-helix tropocollagen molecules, destroying collagen fibril D-periodicity, expanding collagen fiber bundle curling, and loosening of the collagen fiber network. The impairment of multiscale collagen structures degrades the cross-scale mechanical modulus and energy dissipation of dECM from the triple helix molecules to the fibril level to the fiber bundle that extends to the fiber network. This study provides important data for further optimizing decellularized fibrocartilage scaffolds and evaluating their translational potential.

Silk has emerged as an interesting candidate among protein-based nanocarriers due to its favorable properties, including biocompatibility and a broad spectrum of processing options to tune particle critical quality attributes. The silk protein conformation during storage in the middle silk gland of the silkworm is modulated by various factors, including the most abundant metallic ion, calcium ion (Ca²⁺). Here, we report spiking of liquid silk with calcium ions to modulate the silk nanoparticle size. Conformational and structural analyses of silk demonstrated Ca²⁺-induced silk assemblies that resulted in a liquid crystalline-like state, with the subsequent generation of β-sheet-enriched silk nanoparticles. Thioflavin T studies demonstrated that Ca²⁺ effectively induces self-assembly and conformation changes that also increased model drug loading. Ca²⁺ incorporation in the biopolymer feed significantly increased the nanoparticle production yield from 16 to 89%, while simultaneously enabling Ca²⁺ concentration-dependent particle-size tuning with a narrow polydispersity index and altered zeta potential. The resulting silk nanoparticles displayed high biocompatibility in macrophages with baseline levels of cytotoxicity and cellular inflammation. Our strategy for manufacturing biomimetic silk nanoparticles enabled overall tuning of particle size and improved yields─features that are critical for particle-based nanomedicines.