Journal of biomedical materials research. Part B, Applied biomaterials最新文献

To investigate the antibacterial effect, mechanism, and cytotoxicity of Prussian blue/Cerium dioxide (PB/CeO₂) nanoparticles against Enterococcus faecalis (E. faecalis) and biofilm. PB/CeO₂ nanoparticles were synthesized and characterized. The antibacterial mechanism of nanoparticles was explored through peroxidase (POD) activity assay, hydroxyl radicals (·OH) detection, and measurement of bacterial reactive oxygen species (ROS) and glutathione (GSH)/glutathione disulfide (GSSG) levels. The biocompatibility of PB/CeO₂ was evaluated by Cell Counting Kit-8 (CCK-8) assay and histological examination of the major visceral organs of rats. The antibacterial effect of PB/CeO₂ was assessed using the colony-forming unit (CFU) method. The impact of PB/CeO₂ on E. faecalis biofilm on dentin slices was further observed with CLSM and SEM. ANOVA and t-test were applied for statistical analysis (p < 0.05). PB/CeO₂ demonstrated significant antibacterial activity against E. faecalis, mainly when used with H₂O₂, significantly enhancing its antibacterial effect and effectively disrupting E. faecalis biofilms on dentin slices. PB/CeO₂ nanoparticles catalyzed ROS production, disrupting the antioxidant defense system of E. faecalis cells, damaging bacterial cell membranes, and ultimately causing bacterial death. PB/CeO₂ nanoparticles exhibit good biocompatibility at appropriate concentrations in vivo and in vitro. The novel multifunctional nanocomposite shows great antibacterial effects against E. faecalis and its biofilm, with low cytotoxicity and good biocompatibility, offering a novel disinfection strategy for root canal treatment.

Controlled drug delivery systems are crucial for maintaining therapeutic efficacy while minimizing side effects. However, they have long presented a significant challenge in the field of medicine. It is difficult to precisely control the drug release kinetics with conventional drug delivery methods, leading to reduced effectiveness and potential toxicity. As a result, there is an increased demand for advanced drug delivery platforms, capable of providing precise and sustained drug release, thereby improving performance and patient outcomes. Implantable microchips are advanced microelectromechanical systems-based devices that have the potential to revolutionize drug delivery and are the preferred choice for researchers and industry pioneers. They are a promising and superior alternative to traditional systems, as they are biocompatible, easy to manufacture, and have patient-friendly designs. Microchips are designed to provide precise control over both the rate and timing of drug release. A single microchip can be engineered with multiple reservoirs (loaded with different active moieties) via different microfabrication techniques, enabling multi-drug therapy. Currently, most implantable microchips are designed as single-use devices, intended to be removed or replaced once the drug reservoirs are depleted. Nevertheless, research is ongoing to address this issue, and efforts are being made to design refillable microchips. They have a wide range of applications, including chronic disease management for conditions like diabetes and cardiovascular diseases, cancer therapy, and treatment of neurological disorders like Parkinson's disease. The current review offers a comprehensive exploration of the evolution of implantable microchips for drug delivery, tracing their development from inception to the latest advancements along with their working methods and fabrication technologies.

Joint arthroplasty bearing materials must maintain a balance between wear resistance, toughness, and oxidation resistance. Antioxidant-doped polyethylene has been introduced to stabilize free radicals resulting from the cross-linking process while avoiding mechanical property losses associated with previous generations of highly cross-linked polyethylene. Furthermore, the antioxidant should prevent or greatly reduce oxidation occurring in vivo. The purpose of this study is to understand the extent to which retrieved, antioxidant-doped UHMWPE devices exhibit chemical and microstructural signs of oxidation. A group of 261 antioxidant knee bearings from an IRB-approved retrieval database were assessed for oxidation and microstructural changes that would be expected with oxidation. Three different antioxidant materials were included in this study, including diffused vitamin E (VE-D), blended vitamin E (VE-B) and pentaerythritol tetrakis[3-(3,5- di-tert-butyl-4-hydroxyphenyl)] propionate (PBHP), with an emphasis on the latter. Ketone oxidation index (KOI) and crystallinity were assessed for all materials, while crosslink density was assessed for the PBHP materials. In vivo durations were 0–107 months, making this the largest and longest known study of antioxidant efficacy in retrieved devices. Increases to KOI with in vivo duration were minimal, with nearly all values remaining below 0.2 out to the maximum duration observed. These increases were largely attributed to the presence of absorbed species near the material surface, where maximum KOI occurred in most devices. Microstructural changes typically associated with oxidation did not yield any meaningful changes, indicating that polymer degradation is not occurring in these materials to any significant extent. Subsurface KOI peaks were noted in five devices, suggesting that small amounts of polymer oxidation may develop in these materials given the right conditions. However, unlike subsurface ketone peaks associated with oxidation in previous generations of UHMWPE, these were very small and pose no threat to the mechanical properties of the materials. In retrievals evaluated to date, all antioxidant formulations appear to be effectively controlling in vivo oxidation. Small amounts of polymer oxidation observed in several devices are not likely to have clinical relevance. Continued monitoring over the long term will be necessary to ensure this remains the case.

This study developed a biodegradable neural guidance conduit using electrospun poly(lactic-co-glycolic acid) (PLGA) and multiwall carbon nanotubes (MWCNT) to deliver allogeneic Schwann cells (SCs) for enhanced peripheral nerve regeneration. The conduit incorporated fibrin and lycopene-chitosan nanoparticles (Lyco-CNPs) optimized for enhanced stability and drug delivery (diameter: 163 ± 6 nm; zeta potential: −9.3 mV), addressing limitations of prior formulations. Key structural and mechanical properties included a fiber diameter of 251 ± 22 nm, tensile strength of 5.86 ± 0.98 MPa, Young's modulus of 1.68 ± 0.25 MPa, and pore diameter of 21.8 nm, ensuring robustness and nutrient diffusion. In vitro studies confirmed a dose-dependent increase in Schwann cell proliferation via MTT assay with the addition of lycopene nanoparticles (NL). In a 10-mm sciatic nerve defect model in rats, the PLGA-CNT-nanoLyco conduit seeded with SCs demonstrated superior regeneration, evidenced by 35.31% higher myelinated nerve density compared to controls. Histopathological (hematoxylin–eosin/Luxol fast blue) and walking-footprint analysis confirmed enhanced axonal alignment and remyelination. These results highlight the conduit's dual functionality as a structural scaffold and bioactive delivery system for nerve repair.

PMMA bone cement is mainly utilized to stabilize prosthetic implants; however, it is impacted by a variety of obstacles, including a lack of biocompatibility, limited thermal stability, a greater tendency to infection, and restricted mechanical strength. This study incorporates three different boron derivatives, boric acid, borax pentahydrate, and borax decahydrate into the polymethylmethacrylate (PMMA) bone cement formulation, leveraging their antibacterial properties to address the identified challenges. All three bone cement formulations were evaluated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and mechanical analysis. In addition, three formulations of bone cement were evaluated for cellular viability, antibacterial properties, and biocompatibility via a hemolysis assay. Borax decahydrate significantly influenced the biomechanical properties (214.32 MPa) of bone cement samples by decreasing the development of surface porosity in the materials. Borax pentahydrate demonstrated a greater beneficial effect than borax decahydrate in the majority of analyses; nevertheless, the most optimal results were achieved with boric acid. In the 3% boric acid bone cement samples, the cellular viability was significantly enhanced until 14 days as a consequence of the formation of porous structures. Moreover, these bone cement samples exhibited promising antibacterial characteristics and biocompatibility compared to commercial bone cement, both unmodified and antibiotic-incorporated, demonstrating potential features for further research and development.

Magnetic nanoparticles have garnered significant attention in cancer treatment for their dual ability to generate localized heat under an alternating magnetic field and catalyze heterogeneous Fenton-based reactions on their surface. These reactions produce free radicals in mildly acidic and reducing environments, such as the tumor microenvironment, leading to oxidative stress in cancer cells. The synergistic combination of magnetic hyperthermia and catalytic activity enhances oxidative stress induction, underscoring the importance of understanding the cytotoxic effects of this approach. In this study, we performed in vitro toxicity assays on the HepG2 cell line to evaluate cytotoxicity and lipid peroxidation induced by hyperthermia using manganese ferrite nanoparticles with mean sizes of 12 and 28 nm. Magnetic hyperthermia efficiency, quantified by Specific Loss Power (SLP), and catalytic activity, assessed through free radical generation using electron paramagnetic resonance (EPR) and substrate oxidation rates via UV–visible spectroscopy, were characterized prior to the biological experiments. Our results showed that the 28 nm nanoparticles achieved a temperature increase of approximately 11.5°C, compared to 3.6°C for the 12 nm particles. Correspondingly, higher cell death was observed for the 28 nm nanoparticles following magnetic fluid hyperthermia treatment. However, lipid peroxidation was more pronounced with the 12 nm nanoparticles, attributed to their larger surface-to-volume ratio enhancing catalytic performance. In conclusion, nanoparticle size critically influences both magnetic and catalytic properties, and optimizing these parameters is essential for maximizing therapeutic efficacy in magnetic fluid hyperthermia.

Schistosomiasis stands out as a significant neglected tropical disease in Africa, resulting from the blood fluke, Schistosoma sp. The application of nanotechnology in addressing this particular disease is critically essential to mitigate the undesirable side effects associated with chemotherapy. The current investigation aimed to evaluate the efficacy of biosynthesized silver nanoparticles (AgNPs) extracts by Eucalyptus citratus aqueous leaves, as a novel alternative treatment for schistosomiasis, and to compare their effectiveness with Praziquantel (PZQ). Mature worms subjected to AgNPs at concentrations of 3.125, 6.25, 12.5, 25, 50, and 100, and some of the AgNPs concentrations were added to and mixed with PZQ at concentrations of 12.5 + 0.4, 25 + 0.3, 50 + 0.2, and 75 + 0.1 μg/mL. Concentrations of 100 μg/mL of AgNPs showed complete mortality of adult worms after 6 h; 50 and 25 μg/mL after 12 h; and 12.5 μg/mL after 24 h, where the effectiveness of AgNPs was improved by adding PZQ. In vivo, four groups of hamsters infected with Schistosoma mansoni were treated. In the hamsters, the number of eggs present in the tissues as well as the size and number of granulomas significantly decreased when AgNPs and the mixed with PZQ were added. The properties of silver particles synthesized by E. citratus were identical and confirmed by all previous studies. These results demonstrated that green AgNPs with PZQ showed high activity against S. mansoni in laboratory experiments.

Bone tissue engineering offers a promising strategy for repairing massive bone defects, with diverse biomaterials continuously emerging in this field. However, the capabilities of single-material systems increasingly fail to meet the requirements for bone regeneration. There is an urgent need to develop novel composite biomaterials. Herein, we fabricate biphasic calcium phosphate (BCP)/bioglass composite ceramics via digital light processing (DLP)-assisted spark plasma sintering (SPS) and systematically evaluate bioglass-ratio-dependent biological activity, biodegradability, and osteogenic efficacy through in vitro and in vivo models. We determined that 45S5 bioglass at 20 wt.% optimally enhances osteogenic differentiation, demonstrating significant potential for bone defect repair in future clinical applications.