Many elements, such as copper, cobalt (Co), strontium, magnesium and boron (B) have been used for single or multiple doping of bioactive glasses to promote angiogenesis during bone regeneration. However, few works have focused on promoting angiogenesis through stimulating several different signalling pathways which can be called a multi-target approach. In this study, 45S5 bioactive glass (BG) co-doped with B and Co was prepared by conventional melt quenching method. The synergistic effect of the two co-doping elements on angiogenesis promotion was expected. ATR-Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy and inductively coupled plasma-optical emission spectrometry were used to characterize the composition, element distribution and ion release of the samples, respectively. Results showed that the compositions of all samples were consistent with the design compositions and all elements were homogeneously distributed in the bulk glass. Different contents of B and Co led to different release rates of these elements. All samples showed bioactivity after immersion in simulated body fluid, regardless of the amount of doped B and Co. The 1% and 0.1% extracts of all samples did not show any cytotoxicity to MG-63 and ST-2 cells. Compared with single B or Co doping, the B and Co dual doped sample led to a stronger increase of the secretion of vascular endothelial growth factor from ST-2 cells, which supports and confirms the synergistic effect on angiogenesis of B and Co as co-doping elements in 45S5 BG.
Vascularization is necessary in tissue engineering to keep adequate blood supply in order to maintain the survival and growth of new tissue. The synergy of biologically active ions with multi-target activity may lead to superior angiogenesis promotion in comparison to single-target approaches but it has been rarely investigated. In this study, polycaprolactone (PCL) fiber mats embedded with B and Co co-doped bioactive glass nanoparticles (BCo.BGNs) were fabricated as a tissue regeneration scaffold designed for promoting angiogenesis. BCo.NBGs were successfully prepared with well-defined spherical shape using a sol-gel method. The PCL fiber mats embedding co-doped bioactive glass nanoparticles were fabricated by electrospinning using benign solvents. The Young’s moduli of the nanoparticle containing PCL fiber mats were similar to those of the neat fiber mats and suitable for scaffolds utilized in soft tissue repair approaches. The mats also showed non-cytotoxicity to ST-2 cells. PCL fiber mats containing BCo.BGNs with a relatively high content of B and Co promoted the secretion of vascular endothelial growth factor to a greater extent than PCL fiber mats with a relatively low B and Co contents, which demonstrates the potential of dual ion release (B and Co) from bioactive glasses to enhance angiogenesis in soft tissue engineering.
Fiber glass waste (FGW) was subjected to alkali activation in an aqueous solution with different concentrations of sodium/potassium hydroxide. The activated materials were fed into a methane–oxygen flame with a temperature of around 1600 °C. X-ray diffraction analysis confirmed the formation of several hydrated compounds, which decomposed upon flame synthesis, leading to porous glass microspheres (PGMs). Pore formation was favored by using highly concentrated activating alkali solutions. The highest homogeneity and yield of PGMs corresponded to the activation with 9 M KOH aqueous solution.
Liquid phase deposition is a cost-effective and energy-efficient method for obtaining TiO2 films at low temperatures. This work demonstrates the use of a multifunctional template consisting of grafted gallic acid (GA) and hexamethylenediamine (HD) on a Ti substrate to regulate the deposition of TiO2 films. X-ray diffraction characterization shows that films deposited with the template have a more obvious anatase phase compared to direct deposition at 25 °C. The intensity of photoluminescence spectra also shows significant differences at 373.7 nm and 663.3 nm. Furthermore, electrochemical measurements indicate that TiO2 films adjusted by the template have excellent electrochemical conversion properties. This proposed method provides a new simple route for fabricating TiO2 films that are adjusted by GAHD templates, which may have good applications in the fields of semiconductor materials and biological materials.