RESUMO
Effective filling materials, typically bone cements, are essential for providing mechanical support during bone fracture treatment. A current challenge with bone cement lies in achieving continuous drug release and forming porous structures that facilitate cell migration and enhance osteoconductivity. We report a droplet microfluidics-based method for synthesizing uniform-sized gelatin hydrogel beads. A high hydrogel concentration and increased crosslinking levels were found to enhance drug loading as well as release performance. Consequently, the droplet microfluidic device was optimized in its design and fabrication to enable the stable generation of uniform-sized droplets from high-viscosity gelatin solutions. The size of the generated beads can be selectively controlled from 50 to 300 µm, featuring a high antibiotic loading capacity of up to 43% dry weight. They achieve continuous drug release lasting more than 300 h, ensuring sustained microbial inhibition with minimal cytotoxicity. Furthermore, the hydrogel beads are well suited for integration with calcium phosphate cement, maintaining structural integrity to form porous matrices and improve continuous drug release performance. The uniform size distribution of the beads, achieved through droplet microfluidic synthesis, ensures predictable drug release dynamics and a measurable impact on the mechanical properties of bone cements, positioning this technology as a promising enhancement to bone cement materials.
RESUMO
In this study, we aim to develop organic-inorganic hybrid nanofibers containing high moisture retention and good mechanical performance as an antimicrobial dressing platform. The main theme of this work focuses on several technical tasks including (a) the electrospinning process (ESP) to produce organic polyvinyl alcohol/sodium alginate (PVA/SA) nanofibers with an excellent diameter uniformity and fibrous orientation, (b) the fabrication of inorganic nanoparticles (NPs) as graphene oxide (GO) and ZnO NPs to be added to PVA/SA nanofibers for enhancement of the mechanical properties and an antibacterial function to Staphylococcus aureus (S. aureus), and then (c) the crosslinking process for PVA/SA/GO/ZnO hybrid nanofibers in glutaraldehyde (GA) vapor atmosphere to improve the hydrophilicity and moisture absorption of specimens. Our results clearly indicate that the uniformity nanofiber with 7 wt% PVA and 2 wt% SA condition demonstrates 199 ± 22 nm in diameter using an electrospinning precursor solution of 355 cP in viscosity by the ESP process. Moreover, the mechanical strength of nanofibers was enhanced by 17% after the handling of a 0.5 wt% GO nanoparticles addition. Significantly, the morphology and size of ZnO NPs can be affected by NaOH concentration, where 1 M NaOH was used in the synthesis of 23 nm ZnO NPs corresponding to effective inhibition of S. aureus strains. The PVA/SA/GO/ZnO mixture successfully performed an antibacterial ability with an 8 mm inhibition zone in S. aureus strains. Furthermore, the GA vapor as a crosslinking agent acting on PVA/SA/GO/ZnO nanofiber provided both swelling behavior and structural stability performance. The swelling ratio increased up to 1.406%, and the mechanical strength was 1.87 MPa after 48 h of GA vapor treatment. Finally, we successfully synthesized the hybrid nanofibers of GA-treated PVA/SA/GO/ZnO accompanied with high moisturizing, biocompatibility, and great mechanical properties, which will be a novel multi-functional candidate for wound dressing composites for patients receiving surgical operations and first aid treatments.
RESUMO
High-dispersion polystyrene (PS) microspheres with monodispersity were successfully synthesized by the non-emulsification polymerization method, and three-dimensional (3D) photonic crystals of PS microspheres were fabricated by electrophoretic self-assembly (EPSA). The metal nickel inverse opal structure (IOS) photonic crystal, of which the structural thickness can be freely adjusted via electrochemical deposition (ECD), and subsequently, MnS/MoS2/Ni-IOS specimens were also prepared by ECD. Excellent specific capacitance values (1880 F/g) were obtained at a charge current density of 5 A/g. The samples in this experiment were tested for 2000 cycles of cycle life and still retained a reasonably good level of 76.6% of their initial capacitance value. In this study, the inverse opal structure photonic crystal substrate was used as the starting point, and then the microelectrode material for the MnS/MoS2/Ni-IOS supercapacitor was synthesized. Our findings show that the MnS/MoS2/Ni-IOS microelectrode makes a viable technical contribution to the design and fabrication of high-performance supercapacitors.
