Biomedical materials (Bristol, England)最新文献

Titanium and its alloys have excellent mechanical and biocompatibility features, which are commonly utilized in the production of surgical instruments, such as scalpels, surgical tweezers, needle holders, etc. However, lacking antibacterial ability, titanium materials are susceptible to bacterial infection, which hinders the success of surgical operations. Medical titanium substrates were modified using polydopamine (PDA) coatings in this study, followed by cadmium (Cd) and copper (Cu) ions loaded into the PDA coating to endow titanium surgical instruments with antibacterial properties. The surface topography, chemical state, ion release, and other features of the specimen were analyzed. Additionally, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Cd and Cu ions against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were quantitatively determined through serial dilution methodology. The antibacterial features of embellished substrates were investigated against both S. aureus and E. coli. The results demonstrated that the dual-ions (Cd/Cu) modified coating exhibits a reduction in ion release compared to the single ion loaded coatings, with Cd ions demonstrating a 95.13% reduction. Furthermore, the antimicrobial ability of the dual-ions (Cd/Cu) modified coating against S. aureus and E. coli was superior to the PDA coating, with antibacterial rates of 99.89% and 92.04%, respectively. The Cd/Cu co-modified coating demonstrates a balance between low ion release and excellent antimicrobial activity, having great potential for application in antimicrobial surgical instruments.

Embedded bioprinting enables the fabrication of complex, cell-laden structures by extruding bioinks into support baths. This technique has advanced the field of tissue engineering by expanding the range of printable bioinks and enabling the creation of intricate geometries; however, limitations such as instability and inadequate oxygen and nutrient delivery in current support materials restrict long print durations and compromise fidelity. Recently, albumin-based foams have been proposed as oxygen- and nutrient-permeable supports, but their rapid degradation restricts practical use. Here, we report the stabilization of albumin foams through the incorporation of pectin, a biocompatible polysaccharide. Three formulations-albumin-only (A8), albumin with 1% pectin (A8P1), and albumin with 2% pectin (A8P2)-were evaluated for foam stability, bubble morphology, rheology, and physicochemical properties. Pectin significantly delayed drainage and bubble coalescence while maintaining essential rheological features such as shear-thinning and recovery. These improvements enabled the embedded printing of chitosan, a low-viscosity and slow-crosslinking hydrogel, into multilayered and freeform structures with high fidelity. Cell viability assays confirmed that pectin did not compromise biocompatibility; A8P1 provided the most favorable microenvironment and outperformed conventional freeform reversible embedding of suspended hydrogels baths during extended incubation, owing to enhanced oxygen diffusion and a more physiological pH. Overall, pectin-stabilized albumin foams offer a simple, biocompatible, and self-removable support system that addresses key limitations of embedded bioprinting and broadens the range of printable bioinks.

Neurological diseases affect billions of people worldwide, including an array of infections, strokes, cancers, and neurodegenerative disorders like Alzheimer's and Parkinson's, which have seen rising mortality rates in recent decades. The blood-brain barrier (BBB) is a critical protective layer composed of tightly sealed endothelial cells that restrict the entry of most molecules into the brain. Typically, only small, lipophilic molecules can cross the BBB, while larger or hydrophilic drugs face significant delivery challenges. Molecularly imprinted polymers (MIPs) are synthetic materials designed to recognize specific molecules, creating 'molecular memory' for selective binding and release. MIPs offer benefits such as high stability, biocompatibility, sustained drug release, and cost-effectiveness, making them promise for drug delivery and biosensing applications. This review explores the potential of MIPs for targeting receptors on the BBB to improve selective drug delivery to the brain, highlighting design strategies and receptor targets critical for internalization.

Smart drug delivery technologies have become a revolutionary platform in cancer treatment and therapies by enabling precise, stimuli-responsive, and minimally toxic therapeutic interventions. Polyethene glycol-disulphide-poly(lactic-co-glycolic acid) (PEG-SS-PLGA) has received significant interest due to its redox-responsive disulphide functional groups, biodegradability, and ability to self-assemble into nanocarriers with adjustable physicochemical properties. The review provides an overall overview of PEG-SS-PLGA, beginning with its chemical structure, synthesis methods, and significant physicochemical properties. It highlights the use of disulphide bond cleavage in the tumour microenvironment, triggered by redox changes, with higher levels of glutathione, causing its release into the intracellular environment. This also addresses nanoparticle formulation methods, including drug encapsulation, kinetics of release,in vitroandin vivoperformance, as well as applications ranging from monotherapy to co-delivery of chemotherapeutics, siRNA, and immunomodulators. Recent preclinical studies provide evidence of the potential to enhance therapeutic efficacy, reduce multidrug resistance, and offer theranostic imaging capabilities. The review concludes by integrating current knowledge, translational bottlenecks, and recommendations on future directions for optimising them, such as regulatory considerations, preclinical scalability, and incorporation into personalised oncology. Overall, PEG-SS-PLGA represents a promising future platform of targeted, responsive, and multifunctional cancer nanomedicine.

Background Epoxy resin-based sealers (ERBSs) are well-established in endodontics. This review evaluated whether the incorporation of nanoparticles (NP) alters their standardized physicochemical properties and further examined potential dose-response effects and the existence of a minimum effective NP weight percentage. Method PubMed, Scopus, Embase, and Web of Science were searched to January 2025. In vitro studies comparing NP-modified and unmodified ERBSs were included if they evaluated ISO/ANSI-ADA-defined properties. Risk of bias was assessed using the QUIN tool. Pairwise and Bayesian/frequentist network meta-analyses were performed. Results Eleven in vitro studies were included. Pairwise meta-analysis showed lower flow for NP-modified ERBSs at 2 wt% compared to controls (MD= -2.29, 95 %CI - 2.91 -1.68). No significant differences were found for solubility (MD 0.01; 95% CI: -0.09 - 0.12), radiopacity (MD 0.06; 95%CI -0.08 - 0.2), or setting time (MD 18.0833 95 %CI -3.09 - 39.25). Network meta-analysis indicated low NP loadings (0.10-0.15 wt%) most improved flow and solubility, while higher loadings (≥5 wt%) reduced flow. A partial dose-response trend was detected for flow and solubility. Discussion A dose-dependent relationship was observed, with lower percentages improving performance, while higher percentages presented adverse effects. Limitations were identified in the included studies such as the lack of particle characterization, inadequate dispersion techniques, and absence of sample size calculation. Subgroup analyses were not feasible due to limited data. Conclusion NPs can be incorporated into ERBSs without compromising their core physicochemical properties. Low weight percentage may enhance performance, but further standardized research is needed to confirm their effect on antibacterial and biological properties and ensure clinical relevance. .

Respiratory pulmonary infections are a serious threat to human health. Their therapy is primarily based on the use of antibiotics. However, non-specific accumulation and low concentration in the target tissue reduce therapeutic effectiveness, cause side effects, and promote the development of antibiotic resistance. In this study, metal-organic frameworks (MOFs) with MIL-101 (Cr) structure were used for delivery of rifampicin to the lungs. The nanoparticles (NPs) showed high antibiotic loading by mass, namely (127 ± 8)% for MIL-101 (Cr) and (82 ± 7)% for amino-modified NH₂-MIL-101 (Cr). The kinetics of drug release had rapid and prolonged phases with up to 40% of the loaded drug released in 7 h. It induces a significant inhibition of bacterial viability at a concentration of NPs as low as 1 mg l^-1. After intravenous administration, the particles showed high tropism for lung accumulation reaching concentration of almost 300%/g of tissue, more than 10 times higher than concentrations in other tissues. This study demonstrates the effectiveness of using MIL-101 (Cr) MOFs for pulmonary drug delivery and holds significant promise for developing antibacterial therapies.

Implantable antennas play a crucial role in advancing leadless pacemakers, facilitating seamless wireless communication in the restricted and lossy environment of the human body. This research presents the design, simulation, and performance assessment of a miniaturized robot-shaped implantable antenna with enhanced parameters for leadless cardiac pacemakers (LCPs), functioning at the Industrial, Scientific, and Medical (ISM- 2.4-2.48 GHz) band. The proposed implantable antenna is designed on a high dielectric Rogers RO/Duroid 3010, having a thickness of 0.635 mm, serving as a dielectric material for both the substrate and superstrate layers. To maintain the effectiveness of a small radiating patch and ensure optimal performance, the proposed antenna has been designed with a volume of 63.5 mm³(10 mm × 10 mm × 0.635 mm). Incorporating symmetric slots in the radiating patch and ground plane enables miniaturization, impedance matching, improved gain and bandwidth. To evaluate and enhance applicability in a practical scenario, the multilayer cubic phantom model and the human Gustav voxel model have been utilized at the required ISM band. The proposed antenna's equivalent circuit model was also analyzed at the desired band. A link margin analysis is conducted to ensure communication reliability, demonstrating that the antenna can effectively communicate up to 40 m. The proposed antenna exhibits a simulated impedance bandwidth of 380 MHz and a peak realized gain of -23.5 dBi. Additionally, to assess adherence to the IEEE C905.1-2005 safety standards, the specific absorption rate has been evaluated. Further,in-vitromeasurements were carried out in a human tissue-mimicking phantom. The measured results correlate with the simulated results, confirming that the proposed antenna is appropriate for implantation in LCPs.

Objectives: Small-sized bone defects can be repaired by self-healing, but it is difficult for the critical-size bone defect. While autologous bone grafting remains the gold standard, its limited availability, however, constrains widespread clinical application. As a promising alternative, artificial bone substitute scaffolds (ABSS) are designed to mimic the extracellular matrix (ECM) microenvironment. Materials and Methods: In this study, we developed a hierarchically porous PMMA/PEI/ZnO scaffold via anti-solvent vapor-induced phase separation (VIPS), replicating the ECM microenvironment of natural bone. Results: The scaffold exhibited: 1) Structural & Mechanical Properties: A cancellous bone-like porous structure with endogenous stress. 2) In vitro, the scaffolds demonstrated excellent biocompatibility, effectively supporting the adhesion, proliferation, and osteogenic differentiation of rBMSCs. 3) In vivo, this performance consequently translated into enhanced repair of critical-size bone defects (CSBDs) in animal models. Conclusions: This scaffold provides a novel approach for bone tissue engineering, combining structural mimicry, bioactivity, and mechanical strength for effective bone regeneration. .

Infectious bone defects are simultaneously challenged by persistent infection, biofilm-mediated tolerance and impaired bone regeneration, so the conventional debridement-antibiotics-staged reconstruction strategy often fails to achieve infection control and defect repair in one course. Owing to their degradability, broad-spectrum antibacterial activity and the potential to modulate osteogenesis and immunity, zinc-based materials have been regarded as promising candidates for integrated therapy. Based on a systematic search and screening of recent literature, this review summarizes four technical routes-pure zinc and zinc alloys, zinc-containing composite materials, zinc-based coatings and zinc-based delivery systems-and elucidates the antibacterial/anti-biofilm mechanisms of zinc together with its roles in osteogenesis, angiogenesis and immune regulation. On this basis, we propose several engineering design points for clinical translation, including suppression of burst release, regulation of micro-galvanic effects and second-phase distribution, coordinated optimization of surface structure and surface chemistry, and standardized characterization. We also discuss strategies for integrating zinc with current clinical materials (such as antibiotic-loaded bone cement and 3D-printed patient-specific scaffolds), as well as bottlenecks in large-scale manufacturing, long-term safety and the clinical evidence chain. In summary, zinc-based materials are expected to achieve a synergistic effect of infection control-promotion of bone repair-immune homeostasis, thereby providing a feasible materials-based solution and translational roadmap for infectious bone defects.

Artificial dermis is a biological substitute material that mimics the structure and function of human skin, which can protect wounds, guide the reconstruction of the dermal layer, and promote wound healing. Currently, most artificial dermis products employ collagen extracted from animals, but this poses potential risks of rejection and infection during clinical applications. The development of novel artificial dermis formulations capable of mitigating these limitations holds significant clinical importance. In this study, a bilayer artificial dermis composed of a silicone membrane and a collagen sponge was designed. The collagen sponge was formed through genipin-mediated cross-linking of recombinant humanized type III collagen (rhCOL III) and carboxymethyl chitosan (CMCS). The artificial dermis exhibited a bilayer structure comprising a silicone membrane layer and a collagen sponge layer. All artificial dermis groups exhibited favorable porosity, mechanical properties, and hydrophilicity. With increasing CMCS concentration, the material's swelling properties, moisture retention, and resistance to degradation gradually improved. Among these concentrations, CMCS contents of 3%(w/v) and 4%(w/v) exhibited the best performance. The results of hemolysis testing and various cell experiments indicated that the material had great blood compatibility and cytocompatibility. Mouse dorsal whole cortical defect models further confirmed that all experimental groups had been able to promote wound healing, with the 4%(w/v) CMCS group showing the fastest wound recovery rate. Histopathological analysis via hematoxylin and eosin and Masson's trichrome staining revealed well-organized collagen alignment in high-concentration CMCS groups, particularly in the 4%(w/v) CMCS group, accompanied by complete epidermal restoration and nascent skin appendage formation. The epidermis layer was restored to a smooth state and skin appendages were regenerated.