Journal of biomedical materials research. Part A最新文献

Blood oxygenation through the photocatalytic action can be a remarkable phenomenon that holds great potential for the development of artificial lung-assist devices. This process necessitates the use of a semiconductor and a suitable light source. In this work, we propose silver nanoparticles decorated TiO₂ nanotubes (Ag-TNTs) as a photocatalyst. Initially, we fabricated TiO₂ nanotubes through an electrochemical anodization process. Subsequently, silver nanoparticles are loaded onto the TNTs using a UV-light-assisted chemical bath technique. The obtained Ag-TNTs were characterized using the techniques, field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). Hemolysis activity was studied to investigate the biocompatibility of the fabricated samples. For blood oxygenation, the Ag-TNTs are overlaid with blood and exposed to a UV lamp to initiate the photocatalytic reaction. Investigation of the optical absorption studies conducted at regular intervals on the diluted blood samples shows an enhancement in the blood oxygenation (the absorption value at 415 nm is increased from 0.99 to 3.10 ± 0.11), which is also evident in the standard hemoglobin test (15.7–19.9 g/dL). The structure of red blood cells was examined using an optical microscope, and it was observed that there was no hemolysis following the photocatalytic process.

Injuries to dense connective tissues, including the knee menisci, contribute to altered joint biomechanics and degeneration. Though meniscal tears are the most common intra-articular knee injury, potential drivers of regenerative treatments remain unknown. Tissue culture scaffolds which effectively recapitulate the fibrous, anisotropic structure and mechanics of meniscus tissue are essential components for in vitro models to investigate meniscus regeneration. Electrospinning poly-ε-caprolactone (PCL) is commonly employed to create meniscus-mimetic scaffolds. However, PCL fiber hydrophobicity often requires post-fabrication treatment to establish adequate hydrophilicity for processing and efficacy in vitro. Nonionic surfactants, like Span80, are common additives in the electrospinning process that are leveraged to increase hydrophilicity in a single step. This study investigates the effects of increasing Span80 concentration, in both unaligned and aligned electrospun fibers, on sample morphology (fiber diameter, alignment), tensile mechanical properties, surface properties (wettability via water contact angle, serum protein adsorption), and meniscal cell adhesion and matrix protein production. A low concentration of Span80 (10%) had a minimal impact on fiber diameter, fiber alignment, and tensile properties, while significantly increasing sample wettability and meniscal cell adhesion and fibronectin production. On the other hand, a higher Span80 concentration (30%) significantly decreased fiber diameter, tensile properties, and cell numbers, especially in aligned scaffolds. Overall, these results illustrate the utility of Span80, in a concentration dependent manner, for modulating surface wettability, protein adsorption, and tensile properties of meniscus-mimetic fibrous scaffolds while maintaining the material-cell compatibility, representing an adaptable in vitro model designed to interrogate cell behavior in a biologically relevant environment.

Sterilization is of utmost importance for the clinical application of biomaterials. Here, we present our findings on the influence of various sterilization regimes on the mechanical properties and the degradation of calcium carbonate reinforced polycaprolactone (PCL), a commonly used biomaterial for example, for bone substitution. Furthermore, studies on the impact of additives' specific surface were included. It was shown that both gamma and electron beam sterilization with direct and pulsed application of 25 kGy radiation resulted in a decrease of M_N and an increase of M_W, corresponding to the occurrence of chain scission and branching reactions, respectively. Here, pulsation and the use of gamma rays were shown to decrease the impact of sterilization on molecular weight. Overall, sterilization resulted in an increase of Young's moduli in bulk specimens. Identical observations were made regarding an increase in specific additive surface area. In 3D-printed scaffolds, however, no influence of sterilization regime or additive surface area on the mechanical properties was observed. During degradation (hydrolysis), chain scission and branching reactions have contrary effects regarding degradation velocity. Therefore, gamma-sterilized specimens showed no effect, which was attributed to an offset of the effects of both modifications. Electron beam sterilization, however, inhibited degradation due to increased PCL branching reactions. This effect could be circumvented by additives with high specific surface, which showed reduced particle-matrix interaction after electron beam sterilization, attributed to the generation of characteristic high-energy X-ray radiation and radicals in close proximity to calcium carbonate particles.

Wound healing, a complex multifactorial process, continues to pose a challenge, justifying the search for innovative therapeutic approaches to accelerate recovery. In this study, β-cyclodextrin-encapsulated d-limonene (βCD-d-limonene) was formulated and investigated as a promising strategy for wound management. The inclusion complex was successfully synthesized via a simple approach and thoroughly characterized, confirming enhanced physicochemical stability, encapsulation efficiency, and thermal stability. The βCD-d-limonene nanoparticles exhibited a high encapsulation efficiency of 91.97% ± 3.42%. Antimicrobial assessments demonstrated significantly higher antibacterial efficacy of βCD-d-limonene compared to free d-limonene against both Gram-positive and Gram-negative bacteria. A significant 90-fold decrease in the minimum inhibitory concentration (MIC) was recorded for the most susceptible bacterium, Pseudomonas aeruginosa (P. aeruginosa), with values decreasing from 111.2 mg/mL for free d-limonene to 1.24 mg/mL for the βCD-d-limonene complex. In vivo, wound healing studies revealed faster wound closure, reduced inflammation, and improved tissue regeneration. Gene expression analysis demonstrated modulation of key markers such as IL-6, MMP3, BAX, VEGF, and TGF-β1, supporting the inclusion complex's (βCD-d-limonene) role in regulating inflammation, apoptosis, and angiogenesis. Histological and immunohistochemical evaluations confirmed enhanced tissue architecture and cellular response in βCD-d-limonene-treated mice. These results underscore the potential of βCD-d-limonene as a stable, biocompatible, and highly effective therapy, offering a natural platform for wound care and related biomedical applications.

Bioprosthetic heart valves (BHV) fabricated from heterograft tissue such as glutaraldehyde fixed bovine pericardium (BP), while less thrombogenic than mechanical valve prostheses, nevertheless demonstrate a significant risk for platelet initiated thromboembolic events. We showed previously using in vitro and in vivo model systems that pyridoxamine (PYR), a Vitamin B6 vitamer, used as a BP pretreatment, mitigated advanced glycation end product (AGE) formation. PYR is also known to inhibit platelet aggregation. In the present studies, both BP and collagen-coated polyvinyl chloride tubing (PVC-collagen) were fixed with glutaraldehyde and were either untreated or pretreated with PYR; both the PYR content and binding stability were quantitated. PYR-BP binding stability was demonstrated in vitro over 28 days. Methylglyoxal (MGO), a representative AGE, was used to modify BP and PVC-collagen for use in platelet activation studies in an ex vivo flow loop with human whole blood. MGO modified collagen-coated PVC demonstrated both increased platelet activation, per P-selectin expression, and increased platelet adhesion compared to non-MGO modified samples. PYR pretreatment of either collagen-coated PVC or BP, with or without MGO exposure, significantly mitigated these effects. In conclusion, BP and collagen surfaces are susceptible to platelet activation and adhesion that is effectively mitigated by vitamin B6.

Traditional 2D cell cultures and animal models have served as the foundations of biomedical research. These have significant limitations in modeling human physiology and predicting outcomes of therapy. Recent developments in 3D organoids and organ-on-chip technologies have shifted the field by enabling human relevant dynamic and scalable platforms for disease modeling and drug discovery and toxicity evaluation. Organoids derived from either stem cells or patient samples accurately recreate complex cellular structure and function found in human organs. The combination of organoids with organ-on-chip systems, or micro-engineered devices that closely simulate the interactions between distinct organ types including tissue to tissue as well as fluids and mechanical forces, allows researchers to continually monitor and manipulate the immediate environment of cells. The focus of this study will be on the underlying technologies for the manufacture and use of these systems as well as the main applications of these systems. Future research will include the development of multi-organ chips, artificial intelligence (AI), and biosensors. This study also illustrates how organoids and organ-on-chip technologies will enable the modeling and mimicking of common neurological, liver, gut, heart, cancer, and infectious diseases, as well as their application for high-throughput drug screening and nanotoxicology applications which could potentially help to lessen our reliance on animals for preclinical drug testing. The combined use of CRISPR gene editing, multi-omics profiling, and machine-learning technology is accelerating the transition to personalized medicine. In spite of issues surrounding the standards associated with the use of organoid and organ-on-chip technology, ethical issues, and the magnitude of scalability, there continues to be ongoing technical advances and government support for this quickly developing technology. Organoids and organ-on-chip technologies represent a fundamental shift in the practice of biomedical research and may allow us to more closely and accurately simulate authentic human physiology while providing more efficient and safer platform for drug discovery to be conducted.