Journal of biomedical materials research. Part A最新文献

This study presents an innovative approach to improve implant biointegration and reduce implant-associated infections using porous poly(vinyl formal) nanocomposite matrices incorporated with gold nanoparticles and antimicrobial/anticancer drugs for plastic surgery applications. The porous matrices were characterized using physicochemical techniques and in vitro biochemical assays. The results demonstrated the biocompatibility of PVF nanocomposites and their potential for functionalization with various bioactive molecules and drugs, thereby enhancing their therapeutic efficacy. In vivo studies in rabbits revealed progressive replacement of implants with fibrous tissue, indicating successful biointegration with the surrounding soft tissues. Future research will focus on the long-term biocompatibility and functionalization of these nanocomposite implants for plastic surgery and explore their potential in other biomedical applications such as wound healing, tissue engineering, and scaffolds for cell growth and differentiation.

Osteoarthritis (OA) is a prevalen degenerative joint disease with no FDA-approved therapies that can halt or reverse its progression. Current treatments address symptoms like pain and inflammation, but not underlying disease mechanisms. OA progression is marked by increased inflammation and extracellular matrix (ECM) degradation of the joint cartilage. While the role of biochemical cues has been widely studied for OA, how matrix mechanical cues influence OA phenotype remains poorly understood. Using sliding hydrogels (SGs) as a tool, we examine how local matrix compliance in 3D modulates OA chondrocyte phenotype and associated mechanosensing. We demonstrate that local matrix compliance reduces the inflammatory phenotype of OA chondrocytes, as indicated by decreased gene expression of catabolic markers and proinflammatory cytokine secretion. This is achieved via significantly reduced nuclear NF-κB expression and signaling in OA chondrocytes. Live cell imaging shows enhanced cellular and nuclear dynamics with increased matrix deformation in the compliant SG. Blocking cellular dynamics negates SG compliance-induced benefits in reducing OA inflammatory phenotype. Further, SG alters nuclear mechanosensing in OA as indicated by increased nuclear lamin reinforcement and chromatin condensation. Finally, we demonstrate that a drug inhibiting histone lysine demethylase to modulate chromatin accessibility reduces OA inflammation in 3D hydrogels. These findings advance our understanding of how ECM mechanics regulate OA mechanobiology and progression and highlight potential disease-modifying treatments via epigenetic and mechanosensing-based therapies.

Wearable nanocomposite stretch sensors are an exciting new development in biomaterials for biomechanical motion-tracking technology, with applications in the treatment of low back pain, knee rehabilitation, fetal movement tracking, and other fields. When strained, the resistance of the low-cost sensors is reduced, enabling human motion to be monitored using a suitable sensor array. However, current sensor technologies have exhibited significant drift, in the form of increased electrical resistance, if left stored in typical room conditions. The purpose of the present work was to evaluate the influence of several environmental factors, including temperature, humidity, oxygen levels, and light exposure, that could impact the change in electrical properties of these sensors. These physiological conditions are present during use of the sensors on human subjects as well as during sensor storage, making it vital to understand their effects on sensor properties. The electromechanical performance of the sensors stored under a range of conditions was monitored over a period of several weeks. The observations obtained indicate that the presence of oxygen and humidity in the environment where the sensors are stored is the primary contributor to drift in the sensor response. Sensors that are kept in de-oxygenated or desiccated environments do not display an increase in electrical resistance over time. This understanding allows for long-term storage of the sensors without degradation. It also assists in identifying the internal processes at work within the nanoparticle-polymer matrix that cause changes in electrical properties.

Chronic osteomyelitis of the maxillofacial bones (i.e., jaw bones) is a persistent infection that requires effective treatment. Because systemic antibiotics seldom reach necrotic areas to remove bone infection, local antibiotic carriers such as antibiotic-loaded bone cement can be tried. It is critical to assess the biosafety and efficacy of two new antibiotic-loaded biodegradable composite bone cements for treating chronic mandibular osteomyelitis, and their drug eluting efficiency and other relevant aspects prior to clinical trial. The physico-mechanical properties, and drug release capacity of the cements were determined to be suitable for in vivo application. After inducing chronic osteomyelitis with Staphylococcal strains in 30 female rabbit mandibles, bioactive glass composite cement (0.5 g) and biphasic calcium phosphate composite cement (0.5 g) were implanted in 18 defects (nine/test group) for 84 days to compare the therapeutic efficacy with traditional therapy (control, debridement plus antibiotics in nine defects) using microscopic, micrographic, and radiological examination. Antibiotic concentrations in bone (vancomycin: 34.7–53.2 μg/g, tobramycin: 2.1–2.87 μg/g) after 21 days of installation for both cements were sufficient to eradicate pathogens without causing adverse events. In vivo tests suggest that cement groups outperformed (p < 0.05) traditional therapy in terms of infection clearance and osteoconduction. The gross histologic and micrographic scores of biphasic calcium phosphate composite cement (10.33 ± 0.58 and 8.33 ± 1.53, respectively) indicated that the cement barely surpassed (p > 0.05) the other composite cement (12.67 ± 1.53 and 10.0 ± 1.0, respectively). These findings emphasize the potential of antibiotic loaded composite cements as an effective treatment option for chronic maxillofacial osteomyelitis, offering a safer and more efficient alternative to traditional therapy.

Postsurgical adhesions are a common complication associated with surgical procedures; they not only impact the patient's well-being but also impose a financial burden due to medical expenses required for reoperative surgeries or adhesiolysis. Adhesions can range from a filmy, fibrinous, or fibrous vascular band to a cohesive attachment, and they can form in diverse anatomical locations such as the peritoneum, pericardium, endometrium, tendons, synovium, and epidural and pleural spaces. Numerous strategies have been explored to minimize the occurrence of postsurgical adhesions. These strategies include surgical approaches, adhesiolysis, antiadhesive agents, and mechanical barriers which have demonstrated the most promise in terms of efficacy and breadth of indications. In this review, we discuss the use of physical/mechanical barriers for adhesion prevention and outline the most commonly used, commercially available barriers. We then focus on a synthetic, dual-polymer gel composed of carboxymethyl cellulose (CMC) and poly(ethylene oxide) [PEO], which, unlike the more commonly used single-polymer hydrogels, has demonstrated higher efficacy across a greater range of indications and surgical procedures. We review the formulation, mechanical properties, and mechanisms of action of the CMC + PEO dual-polymer gel and summarize findings from clinical studies that have assessed the efficacy of CMC + PEO gels in multiple surgical settings in clinics across the world. In conclusion, the CMC + PEO dual-polymer gel represents an approach to preventing postsurgical adhesions that has been commonly used over the last 20 years and could therefore serve as a foundation for research into improving postsurgical outcomes as well as a drug delivery device to expand the use of gels in surgical settings.

Plasma nitriding is one of the surface modifications that show more effectiveness than other methods. In this study, the plasma-based ion implantation (PBII) technique was performed on the surface of titanium alloy (Ti-6Al-4V, Ti64) using a mixture of nitrogen (N₂) and argon (Ar), resulting in a plasma-nitrided surface (TiN-Ti64). The surface composition of the TiN-Ti64 was verified through X-ray photoelectron spectroscopy (XPS). TiN-Ti64 demonstrated superior hydrophilicity compared with Ti64. TiN-Ti64 exhibited higher surface hardness than the original surface. The biological responses of primary human alveolar bone cells (hAVs) were observed on the TiN-Ti64, revealing greater activation of cell adhesion and spreading compared with Ti64 and the control group (glass coverslip). Moreover, the TiN-Ti64 significantly promoted cell proliferation compared with Ti64 and tissue culture plates. The mineralization of hAVs on the TiN-Ti64 showed a significant increase, almost 20% greater than that of Ti64. Furthermore, a significant upregulation of mRNA expression for osteogenic differentiation marker genes, including BMP2, OCN, OPN, and RUNX2, was observed in TiN-Ti64 compared with other conditions. In addition, the TiN-Ti64 exhibited antibiofilm activity against Streptococcus aureus. In conclusion, the TiN-Ti64, modified with the PBII technique utilizing a mixture of N₂ and Ar, emerges as a promising alternative for surface modification in dental implant applications.

Triggered by the vulnerability to atherosclerotic plaques, cardiovascular diseases (CVDs) have become a main reason for high mortality worldwide. Thus, there is an urgent need to develop functional molecular imaging modalities to improve the detection rate of vulnerable plaques. In this study, polyethyleneimine (PEI) was coated on the surface of mesoporous silica nanoprobes (MSN) loaded with Gd₂O₃ (MSN@Gd₂O₃), followed by coupling the fluorescent dye carboxylated heptamethine cyanine (IR808), and then the dextran sulfate (DS) was modified on the surface of MSN@Gd₂O₃@IR808 by electrostatic adsorption, to construct a targeted and pH-responsive magnetic resonance (MR)/near-infrared fluorescence imaging (NIRF) dual-modal nanoprobe (MSN@Gd₂O₃@IR808@DS nanoparticles). The nanoprobe presented a more concentrated distribution of spherical shapes in transmission electron microscopy. In vitro simulated vulnerable plaque microenvironment (pH = 5.5) presented significant T₁-weighted imaging (T₁WI) signal and longitudinal relaxation in the nanoprobe. Immunofluorescence staining and cellular uptake assays showed that MSN@Gd₂O₃@IR808@DS nanoparticles have the ability to specially bind to scavenger receptors A (SR-A). In vascular endothelium from the high-fat diet (HFD) New Zealand White rabbits, MSN@Gd₂O₃@IR808@DS nanoparticles can exhibit specific contrast-enhanced signals by MR/NIRF dual-modal imaging. In addition, cytotoxicity assays and hematoxylin and eosin (H&E) staining results demonstrated that MSN@Gd₂O₃@IR808@DS nanoparticles have good biocompatibility. Hence, this multifunctional MR/NIRF bimodal nanoprobe provides new experimental and technological ideas for the accurate diagnosis of vulnerable plaques.