温州医科大学

Zn-0.4 Sr and Zn-0.8 Sr (wt%) alloys (denoted ZS0.4 and ZS0.8) were processed by a single-pass friction stir processing (FSP) using a non-shouldered spiral tool (10 mm diameter, 2° tilt angle) at 1300 rpm, 200 mm/min traverse speed, and ∼1 mm plunge depth at room temperature. Mechanical properties were evaluated using tensile testing, nanoindentation, and Vickers and Brinell hardness measurements. Corrosion and degradation behaviors were assessed via electrochemical polarization and 30-day immersion in Hanks' solution and DMEM + FBS. Tribocorrosion resistance was examined by reciprocating friction tests under dry conditions and in liquid-wetted environments of Hanks' solution and DMEM + FBS. Biological performance was assessed using MC3T3-E1, MG-63, and hBMSC cultures, along with a rat subcutaneous implantation model. The horizontally tested ZS0.8 exhibited an exceptional strength-elongation product of 4.1 GPa%, with an ultimate tensile strength of 258 MPa, a yield strength of 210 MPa, an elongation of 15.9%, and a nanoindentation hardness of 2.6 GPa for the SrZn13 phase, compared with 0.7 GPa for the α-Zn matrix. Electrochemical corrosion rates of ZS0.8 were 388 μm/y in Hanks' and 216 μm/y in DMEM + FBS, while 30-day degradation rates were 44.9 μm/y and 27.2 μm/y, respectively. ZS0.8 also exhibited superior tribocorrosion resistance. Biologically, 25% and 50% extracts of ZS0.8 enhanced MC3T3-E1 and MG-63 viability, promoted hBMSC osteogenic differentiation and mineralization, showed potent anti-Staphylococcus aureus activity both in vitro and in vivo, and maintained good biosafety. These findings demonstrate a favorable balance of mechanical, degradation, and biological properties for load-bearing bone-fixation applications.

The current management of neurological disorders remains largely symptomatic. In recent years, stem cell–derived exosomes have emerged as a promising alternative therapeutic strategy. This narrative review synthesizes evidence from preclinical studies investigating the mechanisms and efficacy of exosome-based therapy for neurological conditions. The included studies encompass animal models and in vitro systems. Accumulating preclinical evidence consistently supports the therapeutic potential of stem cell–derived exosomes across several neurological disorders. In Alzheimer’s disease models, stem cell–derived exosomes reduce β-amyloid plaque deposition and attenuate neuroinflammation. For Parkinson’s disease, they exert neuroprotective effects on dopaminergic neurons. They also inhibit α-synuclein aggregation. In ischemic stroke and spinal cord injury, stem cell–derived exosomes promote functional recovery through multiple mechanisms. These include suppressing ferroptosis, promoting angiogenesis, and stimulating axonal regeneration. Improved delivery strategies, such as intranasal administration and hydrogel encapsulation, have further enhanced brain targeting and treatment durability. Despite these promising preclinical findings, several challenges remain. A primary issue is the lack of standardized preparation protocols. Significant uncertainties also exist regarding long-term safety. Furthermore, pathways for clinical translation are still unclear. Future research should prioritize elucidating the underlying mechanisms of exosome therapy. The refinement of targeted delivery systems is equally important. Finally, advancing rigorously designed clinical trials is crucial to facilitate the translation of these therapies into clinical practice.

Multicolor fluorescent polymer materials (MFPMs), owing to their rich color palette, hold significant value across various applications, such as in biomaterials and display materials. To construct these materials, the traditional approach involves incorporating multiple fluorescent molecules of different colors. However, this approach introduces a range of complexities and challenges associated with multiple fluorophores, encompassing aspects such as structural design, synthesis methodologies, purification demands, as well as the practical operability in application scenarios. To overcome this issue, a single fluorophore exhibiting multiple fluorescent colors has been discovered and introduced into MFPMs. This strategy has significantly propelled the vigorous development of multiple research fields, such as information anti-counter-feiting and optoelectronic materials. This review summarizes the recently developed MFPMs based on a single fluorescent molecule, elucidates their preparation methods and color conversion mechanisms, analyzes their application prospects, and offers some insights into the further advancement of this field. This review provides guidance for the design of novel multicolor fluorescent materials and fosters progress in the areas of fluorescent materials, polymer science, and materials science as a whole.

Regulatory T cells (Tregs) play a pivotal role in promoting immune tolerance during organ transplantations, prompting a critical shift from conventional immunosuppression to active immune regulation in therapeutic paradigms. This review synthesizes recent advances in Treg-based therapies for liver, kidney, and heart transplantations, highlighting their capacity to modulate immune responses and prevent allograft rejection, with preclinical studies and early-phase clinical trials demonstrating the safety and feasibility of autologous polyclonal Treg therapy for enhancing graft survival. Despite these promising results, widespread clinical application faces challenges including complex manufacturing, cellular stability in inflammatory environments, and lack of standardized potency assays. Therefore, this review critically assesses emerging strategies, such as antigen-specific chimeric antigen receptor (CAR)-Tregs for precise immune targeting and gene-edited, “off-the-shelf” allogeneic Tregs, aimed at improving scalability and accessibility. By providing a comprehensive overview of current progress and remaining obstacles, this review guides future research and supports the clinical translation of Treg-based therapies to ultimately improve long-term outcomes for transplant recipients.

Female reproductive disorders present significant challenges worldwide. Transfer RNA-derived small RNAs (tsRNAs), a structurally diverse class of non-coding RNAs mainly comprising tRNA halves (tiRNAs) and tRNA-derived fragments (tRFs), have emerged as key regulators in human health and disease. This review outlines the biogenesis and functions of tsRNAs and summarizes their mechanistic involvement and clinical implications across a range of reproductive pathologies. In pregnancy-related complications, such as embryo implantation failure and recurrent spontaneous abortion, aberrant tsRNA profiles perturb trophoblast behavior, endometrial decidualization, and maternal–fetal crosstalk, thereby compromising placental development and pregnancy outcome. In benign gynecological conditions including premature ovarian failure and endometriosis, dysregulated tsRNAs disrupt granulosa cell survival, promote stromal proliferation, and reshape inflammatory signaling, ultimately altering follicular development and uterine homeostasis. As our understanding of tsRNA-mediated pathways deepens, these molecules offer promising potential as diagnostic biomarkers and therapeutic targets for precision medicine in female reproductive disorders.