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

The pathophysiology of breast implant-related adverse outcomes, such as capsular contracture and breast implant-associated anaplastic large cell lymphoma, remains poorly understood. Herein, we explore the direct and indirect effects of smooth and textured implant shells on the viability of cell lines found within the peri-breast implant environment in vitro. The outer silicone shells of Allergan and Mentor breast implants were de-gelled and cut to exactly line the walls of 96-well cell culture plates. Endothelial, fibroblast, and triple negative breast cancer cell lines were cultured in the presence and absence of implant shells over 8 days. To examine indirect effects, fresh media incubated with implant shells were collected and separately cultured with the same cell lines. These media were further diluted with fresh media and given to cells to examine a “dose dependent” response. Additionally, the effect of pre-soaking implant shells in fresh media prior to cell culture was investigated. Serum free media incubated with implant shells were interrogated for presence of nanoparticles. Cell counts at each culture condition were assessed over 8 days. The presence of implant shells consistently demonstrated a negative effect on cell count that persisted across cell lines and experimental conditions, with a greater effect observed from textured surface shells over smooth. Implant fill silicone gel alone did not influence cell count. Implant-conditioned media (CM) similarly exerted a negative effect, even without direct cell exposure to an implant shell. Dilution of the CM attenuated this effect. Pre-soaking implants in high serum media also reduced the negative effect when incubated with cells, suggesting the role of serum protein adsorption. Nanometer-range sized particles were detected in serum-free media incubated with all implants, with a higher concentration released from textured samples. These studies suggest breast implant shells may negatively impact cell viability through several different mechanisms and uncover valuable insights into the cellular interactions and potential effects of these widely used prostheses on their immediate environment.

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.