ACS Biomaterials Science & Engineering最新文献

The study explores the innovative application of stereolithography to address key material and technological limitations in left ventricular assist devices. Currently, the invasiveness of left ventricular assist device implantation presents a significant clinical challenge, and while early studies on miniaturization and less invasive implantation are promising, they encounter a fundamental limitation: blood clot formation. The root cause of this issue lies in the inherent limitations of conventional manufacturing processes, such as machining, which impede the precise optimization of blood flow dynamics within pump impellers. To overcome this significant barrier, a new approach to stereolithography has been proposed as an innovative 3D printing method to fabricate impellers with advanced biomimetic geometries, radically enhancing blood flow and minimizing the risk of thrombus formation. Moreover, the successful fabrication of these impellers with the stereolithography method relied on the development of a special composite material possessing the necessary mechanical properties. Hemocompatibility evaluations confirmed a low thrombogenic profile, minimal immunological response, and limited biological material accumulation. The findings of this research unequivocally demonstrate that stereolithography technology offers revolutionary potential in left ventricular assist device design and manufacturing, enabling the creation of highly complex and functional structures. However, preclinical validation of the long-term safety and durability of these additively manufactured components is essential prior to their translation into clinical application. Recent advancements in biomedical engineering have intensified the pursuit of more efficient and biocompatible circulatory support devices. Titanium impellers, while commonly used in commercial blood pumps, present limitations in terms of weight and hemocompatibility. In this study, a novel impeller design that demonstrates significantly reduced mass and enhanced resistance to clot formation was designed, addressing key clinical challenges associated with current technologies. The improved performance of these developed components highlights their potential for safe and effective long-term cardiovascular support.

This study developed a novel hydrogel with both antioxidant and conductive properties to address the healing requirements of bacterially infected wounds, aiming to eliminate excess reactive oxygen species (ROS) and establish a microenvironment conducive to wound healing. The hydrogel was prepared by blending quaternized carboxyl-functionalized chitosan (QCCS), ε-polylysine (ε-PL) and poly(vinyl alcohol) (PVA), forming a dual physicochemical cross-linked network. Poly(dopamine)-modified Ti₃C₂ MXene (PDA-MXene) contributes both photosensitivity and conductivity. PDA further enhances MXene’s photothermal conversion efficiency and antioxidant capacity, thereby optimizing the hydrogel’s overall performance. Performance testing demonstrates that this hydrogel exhibits excellent mechanical stability, antioxidant activity and ideal conductivity, enabling efficient ROS scavenging. It also displays significant antibacterial effects, good blood compatibility and a marked ability to promote healing in bacterial infection wounds. In summary, the novel conductive gel dressing developed in this study integrates multiple advantages, providing an innovative and feasible solution for the efficient management of clinically infected wounds.

Keloids (KD) are a type of fibrous proliferative skin disease characterized by excessive collagen fiber proliferation due to dysregulation of collagen synthesis and metabolism during the healing process of skin wounds. KD often grows uncontrollably beyond the wound area and presents tumor-like features, severely affecting the physical and mental health of patients. KD has a high rate of recurrence after clinical treatment. Previous studies have demonstrated that NEDD4 plays a key role in scar formation by regulating various signaling pathways. In this study, we observed a significant increase in the expression of NEDD4 in human KD, further suggesting that it may play an important role in the pathogenesis of KD. Therefore, this study aims to explore whether inhibiting NEDD4 expression can suppress keloid growth. To achieve sustained inhibition of NEDD4 expression, we developed a nanoparticle−hydrogel sustained-release system for the delivery of NEDD4 siRNA (si-NEDD4). In vitro, the inhibition of NEDD4 expression in KD cells resulted in a significant suppression of proliferation and migration as well as a substantial reduction in collagen expression and the phosphorylation levels of ERK1/2 and P38. Furthermore, there was a significant upregulation of apoptosis markers. In vivo study demonstrates that the siRNA@NPs-hydrogel system significantly reduced the weight of the xenograft KD tissue, substantially lowered the expression of NEDD4, Col1a1, and Col3a1, and significantly induced the apoptosis level. Overall, our findings suggest that local delivery of si-NEDD4 via a nanoparticle−hydrogel sustained-release system may represent a promising approach for the treatment of KD.

The breast tumor microenvironment encompasses distinct biophysical, biochemical, and cellular aspects, including a dense extracellular matrix and an array of tumor and stromal cells. The dynamics between tumor cells and their microenvironment can alter tumor behavior and impact treatment responses. Herein, tumor-stroma models (tumoroids) were engineered using dense collagen l to spatially compartmentalize a breast tumor mass in either its primary site (breast) or metastatic site (lung) to test the efficacy of photodynamic therapy (PDT) using a photosensitizer (TMPyP4) as a single treatment and in combination with doxorubicin. For tumoroids with a primary stroma, PDT efficacy was comparable for both MCF-7 and MDA-MB-231. In contrast, MCF-7 tumoroids with a metastatic stroma exhibited a greater treatment response with a 7.2-fold decrease in viability compared to the MCF-7 tumoroids with a primary stroma, whereas only a 1.1-fold decrease was seen for the MDA-MB-231 models. For MDA-MB-231 tumoroids with a primary stroma, combination treatment with PDT and doxorubicin gave the best outcomes. The viability data in the 3D models correlated with noninvasive imaging of hypoxia gradients, where hypoxia became progressively alleviated with increasing treatment efficacy. ln summary, these results highlight the necessity to model the tumor stroma as this can directly impact drug efficacy.

There is growing demand for high-throughput light-based surface processing methods for applications such as printing hydrogels, controlling cell circuits with light, or activating materials on demand. However, existing devices often fall short for multiwell plate use, require complex synthesis steps, or lack flexibility for general research needs, usually because they are designed for specific tasks. Here, an open-platform digital light printer (OP-DLP) is introduced for easy synthesis of two-dimensional (2D) hydrogels and spatial activation of biomolecules. The device is controlled via a LabVIEW interface that manages printing settings and planar corrections. Importantly, its open platform design enables the use of different wavelengths and compatibility with various printing vessels. Its utility is demonstrated by hydrogel printing and spatial activation of DNA. Specifically, OP-DLP can produce hydrogel layers of precise thickness in a 96-well format with consistent results across the plate. Additionally, OP-DLP can form 2D gels with specific shapes in different wells, allowing modification of ink composition. Its spatial activation capability is demonstrated by the localized de-caging of photocaged DNA on a surface.

Chronic wounds in diabetic and immunocompromised patients often remain inflamed due to infection and high levels of pro-inflammatory cytokines. Effective dressings require biocompatibility and active functions to promote healing and reduce inflammation. Conventional dressings lack bioactive agents, cell compatibility, and sustained therapeutic release properties. This study developed dual-functional wound mats by combining molecular docking and electrospinning to load Rumex abyssinicus (RA) extracts into poly(vinyl alcohol)-polyvinylpyrrolidone (PVA–PVP) nanofibers. Molecular docking revealed that γ-sitosterol strongly binds to tumor necrosis factor-alpha (TNF-α) (−11.6 kcal/mol) and transforming growth factor beta-1 (TGF-βR I) (−11.2 kcal/mol), while phytol and linolenic acid derivatives showed moderate interactions with inflammatory and microbial targets. These compounds met the drug-likeness and absorption, distribution, metabolism, excretion, and toxicity (ADMET) criteria. The RA-loaded nanofibers (180–450 nm) were uniform and bead-free, as confirmed by Fourier-transform infrared spectroscopy and X-ray diffraction. The mats exhibited moderate hydrophilicity (contact angle 65°–70°), controlled biodegradability over 14 days, and optimal water vapor transmission rates (1450–1650 g/m²/day) for moist healing. RA release was sustained, reaching 80% at 72 h. The mats exhibited concentration-dependent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) and high cytocompatibility (105.6–116.5%). In vivo, RA mats accelerated wound closure to 97% by Day 15, enhanced collagen deposition (75%), reduced inflammation (18%), and suppressed TNF-α and interleukin-6 (IL-6) by up to 85 and 95%, respectively. By integration of phytochemicals from renewable plant sources with water-soluble and biocompatible polymers, this study contributes to the development of sustainable wound-care materials. RA-based nanofibers are promising multifunctional wound-dressing materials.

Microorganisms live in environments where mechanical forces, such as fluid shear, surface tension, or pressure, shape their adhesion, biofilm formation, and maturation strategies. Microbes employ force-sensitive molecular switches embedded in surface appendages like flagella, pili, and adhesins like ALS1p or FLO11p to interpret mechanical cues. These mechanical cues trigger chemosensation or generate conformational changes in mechanosensors, thereby activating downstream signaling cascades and modulating gene expression. Ultimately, these mechanical stimuli affect microbial adhesion to surfaces, biofilm resilience, and architecture, often enhancing pathogenicity and virulence. Yet, the mechanobiological basis of these events remains underexplored. In this perspective, we discuss how bacterial and fungal systems use mechanosensation to navigate complex surfaces, underscore the challenges in monitoring real-time molecular responses to force, and explore emerging tools to reveal force-driven molecular dynamics. We highlight insights for synthetic microbiologists, materials scientists, and biomedical engineers into microbial mechanosensation and its translational potential, guiding the development of next-generation antimicrobial strategies to prevent and disrupt persistent biofilms in clinical and industrial settings.

One of the recent innovations in the field of hard tissue regeneration is the development of energy-harvesting self-powered implants. Self-powered implants are known for providing extrinsic electrical stimulations to the defective sites of bone, resulting in accelerated bone regeneration. Towards this end, our study focuses on the development of electroactive BaTiO₃-modified poly(vinylidene) fluoride (PVDF) self-powered hybrid scaffolds using solvent casting and hot compression molding. The power developed by PVDF, PVDF-15 wt % BaTiO₃ (PVDF-15BT), PVDF-25 wt % BaTiO₃ (PVDF-25BT), and PVDF-35 wt % BaTiO₃ (PVDF-35BT) are ∼0.591 μW/cm², ∼5.049 μW/cm², ∼6.300 μW/cm², and ∼7.516 μW/cm², respectively. The polarizability of the hybrid scaffolds was assessed using relative permittivity, AC conductivity, P–E hysteresis analysis, and energy density measurements. The incorporation of BT filler significantly enhances the dielectric and piezoelectric behaviors. MG-63 cell culture studies were performed to assess cytocompatibility through fluorescence imaging and viability assays. Osteogenic potential was evaluated via Alkaline Phosphatase (ALP) activity and Alizarin Red S staining for calcium deposition, while hemocompatibility tests confirmed the materials’ blood-contact safety. Cell proliferation, osteogenic differentiation (ALP), hemocompatibility, and calcium deposition of osteoblast-like MG-63 cells are substantially augmented. These outcomes recommend that BT-modified PVDF self-powered hybrid scaffolds are suitable for hard tissue regeneration.

Magnesium-based biodegradable implants exhibit significant potential due to their biocompatibility and suitable mechanical properties; however, their rapid corrosion remains a major limitation for clinical applications. Surface modification via ion implantation offers a promising approach to enhance performance; however, the specific effects and mechanisms of iron and zinc implantation require further elucidation. In this study, Fe and Zn were implanted into the surface of pure magnesium using metal vapor vacuum arc technology to enhance its corrosion resistance, mechanical properties, and biocompatibility. The study revealed that low-dose Fe implantation increased polarization resistance (R_p) to approximately 2.08 × 10³ Ω cm², whereas high-dose Zn implantation achieved 2.13 × 10⁴ Ω cm², reducing degradation rates to 21.67 and 3.29 mm y^–1, respectively. Fe implantation strengthened the material via dislocation formation and lattice distortion, increasing the hardness by 157%, whereas Zn implantation formed a dense ZnO/MgO film, reduced the carrier concentration, and improved the hardness by 141%, thereby effectively stabilizing the corrosion process. As a result, the corrosion mechanism shifted from hydrogen evolution-dominated in pure Mg to pitting in Fe-implanted samples and more uniform corrosion in Zn-implanted samples. Moreover, both treatments significantly promoted cell proliferation and reduced cytotoxicity. These findings elucidated the multiscale mechanisms of ion-implanted magnesium-based materials and provided quantitative guidance for the design of high-performance biodegradable Mg implants.