Polylactic acid (PLA) is a biodegradable polymer with high tensile strength, high stiffness, and biocompatibility, but its brittleness and hydrophobicity limit its applications. This study aims to address these limitations by blending PLA with polycaprolactone (PCL) to enhance flexibility and with polyethylene oxide (PEO) to improve hydrophilicity. Unlike conventional approaches where PEO serves as a plasticizer, this study investigated PEO as a major blend component. Electrospinning and solvent casting, which differ in their solvent evaporation rates, were employed to fabricate thin films of neat PLA and PLA blends to examine their influence on mechanical and surface properties. Polymer solutions were prepared using a dichloromethane (DCM)/dimethylformamide (DMF) mixture known to enhance the electrospinning process. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were used to investigate crystallinity of polymers and their interactions, while scanning electron microscopy (SEM) and atomic force microscopy (AFM) provided insights into phase separation and fiber morphology. Uniaxial tensile testing and water contact angle measurements were conducted to evaluate mechanical properties and surface properties, respectively. The results showed that electrospun PLA films exhibited higher elongation at break and ultimate strength but lower Young’s modulus than solvent-cast PLA films. Electrospun films of PLA/PCL blends demonstrated improved elongation at break while retaining Young’s modulus comparable to that of electrospun PLA films, unlike their solvent-cast counterparts. In contrast, PLA/PEO blends exhibited enhanced hydrophilicity in both processing methods but showed a marked reduction in mechanical properties. In summary, electrospun films consistently outperformed solvent-cast films in terms of flexibility and mechanical integrity, primarily due to their fibrous structure, suppressed phase separation, and reduced crystallinity. This study uniquely demonstrates that electrospinning enables the fabrication of phase-separated PLA/PEO blends with mechanical integrity despite PEO’s inherent immiscibility with PLA and incompatibility in the solvent mixture. Furthermore, electrospinning proves to be an effective processing method for producing PLA blend films with enhanced flexibility and hydrophilicity without the need for plasticizers or compatibilizers.

Calcium phosphate cement (CPC) is similar to bone in composition and has plasticity, while mesoporous bioactive glass (MBG) has the advantage of releasing Si, which can promote osteogenic properties and drug loading capacity. A sol–gel-prepared MBG micro-powder (mMBG) and further impregnated antibiotic gentamicin sulfate (Genta@mMBG: 2, 3, and 4 mg/mL) antibiotic were added to CPC at different weight ratios (5, 10, and 15 wt.%) to study CPC’s potential clinical applications. Different ratios of mMBG/CPC composite bone cement showed good injectability and disintegration resistance, but with increasing mMBG addition, the working/setting time and compressive strength decreased. The maximum additive amount was 10 wt.% mMBG due to the working time of ~5 min, the setting time of ~10 min, and the compressive strength of ~51 MPa, indicating that it was more suitable for clinical surgical applications than the other groups. The 2Genta@mMBG group loaded with 2 mg/mL gentamicin had good antibacterial activity, and the 10 wt.% 2Genta@mMBG/CPC composite bone cement still had good antibacterial activity but reduced the initial release of Genta. 2Genta@mMBG was found to have slight cytotoxicity, so 2Genta@mMBG was composited into CPC to improve the biocompatibility and to endow CPC with more advantages for clinical application.

Background: Previous studies have reported that vitamin D supplement could improve fracture healing, but evidence regarding the role of vitamin D supplements in spinal fusion was limited. Thus, this study aimed to evaluate the effectiveness of oral vitamin D supplements on fusion outcomes in patients undergoing lumbar spinal fusion. Methods: This randomized, double-blind, parallel-designed, active-control trial included the patients who planned for elective lumbar spinal fusion. Eligible patients were randomly assigned to receive either daily vitamin D3 (cholecalciferol) 800 IU and daily calcium citrate 600 mg (experimental group) or only daily calcium citrate 600 mg (control group). All supplements were given from postoperative day 1 and lasted for 3 months. Primary outcome was postoperative 1-year fusion rate, and secondary outcomes included time to fusion, Oswestry Disability Index (ODI), and visual analogue scale (VAS) for pain. Results: Among the included 34 patients (21 in the experimental group and 13 in the control group), baseline 25-hydroxyvitamin D (25[OHVitD) level was 26.7 (10.4) ng/ml. Preoperative prevalence of vitamin D deficiency and insufficiency were 23.5% and 47.1%, respectively. Postoperative 1-year fusion rate was not significantly different between the two groups (95.2% vs. 84.6%, P = 0.544). The experimental group had significantly shorter time to fusion (Kaplan–Meier estimated: 169 days vs. 185 days [interquartile range: 88–182 days vs. 176–324 days], log-rank test: P = 0.028), lower postoperative 6-month ODI (P < 0.001), and lower postoperative 6-month VAS (P < 0.001) than the control group. Time to fusion was significantly and negatively correlated with preoperative, postoperative 3-month, and 6-month 25(OH)VitD levels (all P < 0.01). Conclusion: The patient with vitamin D supplements had shorter time to fusion, better spinal function and less pain after elective spinal fusion. Further research is warranted to identify the patients who can benefit the most from vitamin D supplements and the appropriate dose of vitamin D supplements. Trial registration: ClinicalTrials.gov, NCT05023122. Registered 20 August 2021. Retrospectively registered, http://clinicaltrials.gov/ct2/show/NCT03793530.

We report the feasibility of using gelatin hydrogel networks as the host for the in situ, environmentally friendly formation of well-dispersed zinc oxide nanoparticles (ZnONPs) and the evaluation of the antibacterial activity of the as-prepared composite hydrogels. The resulting composite hydrogels displayed remarkable biocompatibility and antibacterial activity as compared to those in previous studies, primarily attributed to the uniform distribution of the ZnONPs with sizes smaller than 15 nm within the hydrogel network. In addition, the composite hydrogels exhibited better thermal stability and mechanical properties as well as lower swelling ratios compared to the unloaded counterpart, which could be attributed to the non-covalent interactions between the in situ formed ZnONPs and polypeptide chains. The presence of ZnONPs contributed to the disruption of bacterial cell membranes, the alteration of DNA molecules, and the subsequent release of reactive oxygen species within the bacterial cells. This chain of events culminated in bacterial cell lysis and DNA fragmentation. This research underscores the potential benefits of incorporating antibacterial agents into hydrogels and highlights the significance of preparing antimicrobial agents within gel networks.