Journal of Materials Science: Materials in Medicine最新文献

Cerium dioxide (CeO₂) nanozymes are capable of mimicking the activities of superoxide dismutase (SOD) and catalase (CAT), thereby facilitating the scavenging of reactive oxygen species (ROS). This study aims to synthesize CeO₂ nanozymes with different morphologies by controlling reaction conditions and to elucidate the relationship between morphology and antioxidant and anti-inflammatory activities of the same material. The successful preparation of CeO₂ nanozymes with different morphologies was confirmed by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Our findings revealed that CeO₂ nanotubes exhibited the strongest total antioxidant capacity. More importantly, all CeO₂ nanozymes with different morphologies demonstrated excellent ROS scavenging abilities and effectively inhibited the activation of the NF-κB signaling pathway, reduced phosphorylated p65 (P-p65) protein levels, and consequently decreased the release of pro-inflammatory cytokines such as IL-6. This study not only elucidates the structure-activity-anti-inflammatory efficacy relationship of CeO₂ nanozymes but also provides a significant theoretical basis for the development of novel anti-inflammatory nanomedicines.

Despite ongoing research efforts, spinal cord injury (SCI) remains one of the most disabling neurological disorders where current therapies provide limited solutions that mostly address symptoms rather than true regeneration. The latest research indicates that exosome-loaded hydrogel systems could function as a dual-purpose treatment for spinal cord injury in regenerative medicine. Exosomes are tiny membrane-enclosed extracellular vesicles that carry multiple therapeutic biomolecules which help control inflammation while delivering neuroprotective and tissue regenerative properties. The structural support and controlled release capabilities of hydrogels allow them to encapsulate exosomes which leads to their stable and bioactive delivery to the injury site. This study evaluates recent progress in exosome-loaded hydrogel technology for spinal cord injury repair by examining SCI mechanisms and the advantages of combining exosomes with hydrogels to develop optimized delivery systems. Our discussion will cover both the challenges of standardizing exosome production and hydrogel formulation as well as the scalability of these systems for in vivo applications. The following review will provide a summary of this novel SCI treatment approach and set out research directions to develop a therapy that is efficient, scalable, and translatable to humans.

The uveoscleral outflow pathway is one of the important pathways for aqueous humor outflow. Implanting ab interno glaucoma drainage devices through this pathway does not require conjunctival filtering bleb formation, thereby avoiding bleb-related complications. However, permanent drainage devices can easily cause damage to the corneal endothelium. We hypothesize that a novel ab interno supraciliary HA-Mg biodegradable glaucoma drainage plate through the uveoscleral pathway can reduce corneal endothelial cell damage, demonstrate an IOP-lowering effect, and form and maintain a physiological aqueous outflow pathway after complete degradation and absorption. Sixteen New Zealand white rabbits were randomly assigned to three groups: HA-Mg drainage plate group (10 right eyes), trabeculectomy group (6 right eyes), and control group (16 left eyes). Results showed that the intraocular pressure (IOP) in the ab interno plate group was significantly lower than in the other two groups within the first 20 weeks after surgery (P < 0.0001). After 21 weeks, the IOP in the ab interno plate group gradually returned to the levels of the other two groups. Within 5 months after surgery, the plate was completely degraded and absorbed, the aqueous humor drainage pathway extended to the supraciliary space at the anterior chamber angle, and a water sac-like gap formed above the ciliary body. At the 6th month postoperatively, the number of corneal endothelial cells in the ab interno supraciliary HA-Mg drainage plate group was 2446.0 ± 104.3, and in the control group was 2391.67 ± 49.6, revealing no statistically significant difference (t = -1.611, P = 0.168). In summary, the HA-Mg biodegradable glaucoma drainage plate placement in rabbits was well fixed in the supraciliary space. After 5 months of implantation, the internal drainage plate was completely absorbed, and the implantation procedure and degradation process did not cause damage to the corneal endothelial cells. Compared with the trabeculectomy group, the ab interno plate group maintained a significantly lower IOP for a longer period in this normotensive rabbit model. Although an aqueous humor drainage channel was formed after degradation, the IOP gradually returned to the levels of the control group.

Via a solid-state reaction route, magnetic composites of chicken eggshell-derived β-tricalcium phosphate (β-TCP, referred to as TCP in the composite system) and zinc-nickel spinel ferrite (ZNF; Zn_xNi_1‒xFe₂O₄, x = 0.2, 0.4, 0.6, or 0.8) were successfully fabricated. Discs were prepared by uniaxial pressing of milled ZNF/TCP powders and sintered at 1200 °C. Cytocompatibility of all composites was confirmed by SEM observations of human osteoblasts (h-OBs) and MTT assays. At 4-wt% ZNF addition, the composites containing Zn_0.8Ni_0.2Fe₂O₄ (Z8NF) exhibited the greatest extent of early cell spreading and were selected for further investigation. For Z8NF/TCP composites containing 4-12 wt% Z8NF, the 8-12 wt% samples demonstrated the highest levels of cell colonization, while MTT assays suggested non-cytotoxic behavior, with cell viabilities comparable to β-TCP. High-temperature sintering induced partial transformation of β-TCP to β-calcium pyrophosphate (β-CPP), as evidenced by XRD and Rietveld refinement. Increasing Z8NF content promoted β-CPP formation and increased composite porosity, whereas densification and Vickers hardness decreased accordingly. Rietveld refinement further indicated that the detectable crystalline Z8NF phase persisted as a minor yet stable secondary phase ( < 2 wt%) and did not participate in Ca-P lattice substitution. For the 8-12 wt% composites, saturation magnetization decreased with increasing Z8NF because of higher porosity and dilution by the non-magnetic β-TCP/β-CPP matrix, while coercivity increased owing to enhanced effective magnetic anisotropy in the more porous microstructure. Overall, the Z8NF/TCP composites combined biodegradability, bioactivity, and tunable soft-magnetic properties, suggesting their potential for bone repair and bone tissue engineering applications.

The development of bone repair scaffolds has long been a research hotspot in tissue engineering. Owing to its unique capability for personalized customization of scaffold geometry and microstructure, 3D printing technology has been extensively adopted for fabricating bone repair scaffolds. Poly-L-lactic acid (PLLA), endowed with favorable biodegradability, excellent biocompatibility, and reliable in vivo safety, is widely used as a matrix material for 3D printed bone repair scaffolds. PLLA is a bioinert polymer characterized by inferior cell adhesion and osteogenic differentiation capabilities. To mitigate this bioinertness limitation, the present study employed N-methylpyrrolidone (NMP) etching to modify the surface of 3D-printed PLLA bone repair scaffolds. Following NMP etching for 1-24 h, the originally smooth scaffold surface evolved into a hierarchical, petal-like gradient microstructure, accompanied by a marked increase in surface roughness. Correspondingly, the hydrophilicity of the treated scaffolds was also enhanced. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses further confirmed that the crystallinity of PLLA in the scaffolds was significantly enhanced. Concomitantly, the modified scaffolds exhibited a marked improvement in adsorption capacity for green fluorescent protein (GFP), while the adhesion and proliferation of MC3T3-E1 on their surface were also significantly promoted. In vivo animal experiments demonstrated that the NMP-etched scaffolds could accelerate the process of bone defect repair. Collectively, surface modification of 3D-printed PLLA bone scaffolds via NMP etching enables precise modulation of their physicochemical properties, thereby effectively mitigating the inherent bioinertness limitation of PLLA scaffolds.