Biofunctionalized hydrogel composed of genipin-crosslinked gelatin/hyaluronic acid incorporated with lyophilized platelet-rich fibrin for segmental bone defect repair.

Segmental bone defects can arise from trauma, infection, metabolic bone disorders, or tumor removal. Hydrogels have gained attention in the field of bone regeneration due to their unique hydrophilic properties and the ability to customize their physical and chemical characteristics to serve as scaffolds and carriers for growth factors. However, the limited mechanical strength of hydrogels and the rapid release of active substances have hindered their clinical utility and therapeutic effectiveness. With ongoing advancements in material science, the development of injectable and biofunctionalized hydrogels holds great promise for addressing the challenges associated with segmental bone defects. In this study, we incorporated lyophilized platelet-rich fibrin (LPRF), which contains a multitude of growth factors, into a genipin-crosslinked gelatin/hyaluronic acid (GLT/HA-0.5 % GP) hydrogel to create an injectable and biofunctionalized composite material. Our findings demonstrate that this biofunctionalized hydrogel possesses optimal attributes for bone tissue engineering. Furthermore, results obtained from rabbit model with segmental tibial bone defects, indicate that the treatment with this biofunctionalized hydrogel resulted in increased new bone formation, as confirmed by imaging and histological analysis. From a translational perspective, this biofunctionalized hydrogel provides innovative and bioinspired capabilities that have the potential to enhance bone repair and regeneration in future clinical applications.

Investigation of in vitro bioactivity, and osteoblast and angiogenic activity of spray-dried boron-doped 58S bioactive glass microspheres.

Bioactive glass is a potential biomaterial for bone reconstruction owing to its superior bioactivity and non-toxicity. Yet, the absence of a circulatory system to carry waste and nutrients is a key issue with biomaterials implanted in the body. Thus the development of functional and vascularized new tissue requires the development of angiogenesis, which involves the formation of new blood vessels. Based on this perspective, we aimed to fabricate boron-doped 58S bioactive glass microspheres using the spray drying method, which could offer great flowability, controllable morphology, and narrow size distribution. Characterization of particle morphology and elemental composition were examined using scanning electron microscopy along with energy dispersive spectroscopy, respectively. To evaluate the effect of the boron dopant on in vitro bioactivity, X-ray diffraction and Fourier transform infrared spectroscopy were employed, while MC3T3-E1 osteoblast cells and BAOEC endothelial cells were used to assess the in vitro osteoblast and angiogenic activities, respectively. Finally, the results showed that two distinct morphologies, smooth and concave spheres, were found, with discussion of the corresponding formation mechanism. In addition, positive effects of the boron dopant were demonstrated on the in vitro bioactivity, and osteoblast and angiogenic activity when compared to the un-doped BG specimen.

An Investigation on Spray-Granulated, Macroporous, Bioactive Glass Microspheres for a Controlled Drug Delivery System.

Bioactive glass (BG) has been regarded as an excellent candidate for biomedical applications due to its superior properties of bioactivity, biocompatibility, osteoconductivity and biodegradability. Thus, in this study, we aimed to fabricate drug carriers that were capable of loading therapeutic antibiotics while promoting bone regeneration using macroporous BG microspheres, prepared by a spray drying method. Characterizations of particle morphology and specific surface area were carried out via scanning electron microscopy and nitrogen adsorption/desorption isotherm. Evaluations of in vitro bioactivity were performed based on Kokubo's simulated body fluid to confirm the formation of the hydroxyapatite (HA) layer after immersion. In addition, the in vitro drug release behaviors were examined, using tetracycline as the therapeutic antibiotic in pH 7.4 and 5.0 environments. Finally, the results showed that BG microspheres of up to 33 µm could be mass-produced, targeting various therapeutic situations and their resulting bioactivities and drug release behaviors, and related properties were discussed.

Correlation of Morphology and In-Vitro Degradation Behavior of Spray Pyrolyzed Bioactive Glasses.

Bioactive glass (BG) is considered to be one of the most remarkable materials in the field of bone tissue regeneration due to its superior bioactivity. In this study, both un-treated and polyethylene glycols (PEG)-treated BG particles were prepared using a spray pyrolysis process to study the correlation between particle morphology and degradation behavior. The phase compositions, surface morphologies, inner structures, and specific surface areas of all BG specimens were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption/desorption, respectively. Simulated body fluid (SBF) immersion evaluated the assessments of bioactivity and degradation behavior. The results demonstrate three particle morphologies of solid, porous, and hollow factors. The correlation between porosity, bioactivity, and degradation behavior was discussed.

Control of Dopant Distribution in Yttrium-Doped Bioactive Glass for Selective Internal Radiotherapy Applications Using Spray Pyrolysis.

In this study, we demonstrate the fabrication of Y-doped bioactive glass (BG), which is proposed as a potential material for selective internal radiotherapy applications. Owing to its superior bioactivity and biodegradability, it overcomes the problem of yttrium aluminosilicate spheres that remain in the host body for a long duration after treatment. The preparation of Y-doped BG powders were carried out using a spray pyrolysis method. By using two different yttrium sources, we examine the change of the local distribution of yttrium concentration. In addition, characterizations of phase information, particle morphologies, surface areas, and bioactivity were also performed. The results show that both Y-doped BG powders are bioactive and the local Y distribution can be controlled.

Morphology Control of Eu-Doped Amorphous Gehlenite Phosphors Prepared by Spray Pyrolysis.

Eu-doped amorphous gehlenite phosphors with various morphologies were synthesized using spray pyrolysis. Along with un-treated precursor, two commonly used pore-forming agents, polyethylene glycol and hydrogen peroxide, were applied to achieve porous and hollow particle structures. The phase compositions, surface morphologies, inner structures and photoluminescence properties of the resulting phosphors were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and fluorescence spectrometry. The results showed that the morphologies of the particles were well-controlled, and a correlation between morphology and photoluminescence properties was established.

The Correlation of Pore Size and Bioactivity of Spray-Pyrolyzed Mesoporous Bioactive Glasses.

SiO2-CaO-P2O5-based mesoporous bioactive glasses (MBGs) were synthesized by spray pyrolysis in this study. Three commonly used non-ionic tri-block copolymers (L121, P123, and F127) with various lengths of hydrophilic chains were applied as structural templates to achieve different pore sizes. A mesoporous structure was observed in each as-prepared specimen, and the results showed that the L121-treated MBG had the largest pore size. The results of bioactivity tests indicated that the growth of hydroxyapatite is related to the pore size of the materials.

Monodispersity of magnetic immuno-nanoprobes enhances the detection sensitivity of low abundance biomarkers in one drop of serum.

To enhance the detection sensitivity of target clinical protein biomarkers, a simple and rapid nanoprobe-based immuno-affinity mass spectrometry assay employing biocompatible monodisperse magnetic nanoparticles (MNPs) is reported herein. The MNPs were synthesized via a streamlined protocol that includes (a) fabrication of core MNPs using the thermal decomposition method to minimize aggregation, (b) surface protection by gold coating (MNP@Au) and surfactant coating using MNP@IGEPAL to improve hydrophilicity, and lastly, (c) oriented functionalization of antibodies to maximize immuno-affinity. The enrichment performances of the monodisperse MNPs for the C-reactive protein (CRP) serum biomarker were then evaluated and compared with aggregated magnetic nanoparticles synthesized from the conventional co-precipitation method (MNP(CP)). The detection sensitivity for CRP at an extremely low amount of serum sample (1 µL) was enhanced ∼19- and ∼15-fold when monodisperse MNP@Au and MNP@IGEPAL, respectively, were used. Furthermore, the detection sensitivity of CRP by this approach (1 ng mL(-1), S/N = 3) provided a 1000-fold sensitivity enhancement to the clinical cut-off (1 µg mL(-1)) of CRP. We supposed that these observed improvements are due to the enhanced nanoparticle dispersibility and size uniformity which eliminated completely other non-specific binding of high-abundance serum proteins. Most interestingly, the enrichment efficiency correlates more closely with the MNP dispersibility than the ligand density. Our investigation revealed the critical role of MNP dispersibility, as well as provided mechanistic insight into its impact on immunoaffinity enrichment and detection of CRP in one drop of serum sample. This strategy offers an essential advantage over the other methods by providing a simple and facile biofunctionalization protocol while maintaining excellent solvent dispersibility of MNPs.

The Influence of Phase Separation on Bioactivity of Spray Pyrolyzed Bioactive Glass.

In this study, bioactive glass (BG) particles were synthesized directly using spray pyrolysis (SP). Since the bioactivity of glass particles is well correlated with their chemical composition, how to obtain homogenous bioactive glass becomes an important issue. For SP, the main reason for chemical inhomogeneity was considered to be caused by the difference in the precipitation speed of each precursor. So, two Si-containing precursors of BG, namely tetraethyl orthosilicate (TEOS) and silicon acetate (SiA), have been applied to prepare BG particles. The bioglasses were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy to examine their phase composition, and surface structures, inner morphologies and chemical compositions. It was observed that, under the calcination temperature of 700 degrees C, TEOS-derived powder contained Si-rich nanoparticles and Si-deficit submicron particles as inhomogeneity, whereas the SiA-derived powder was homogenous. The reason of inhomogeneity is that TEOS dissolves in "volatile" ethanol more readily than in water via the SP mechanism of "gas-to-particle-conversion" to form Si-rich nanoparticles. The presence of Si-rich nanoparticles causes Si-deficit "wollastonite submicron particles" to form, which impairs the bioactivity. Finally, BG particle formation mechanisms from different precursors have been proposed.

Effective cerebral connectivity during silent speech reading revealed by functional magnetic resonance imaging.

Seeing the articulatory gestures of the speaker ("speech reading") enhances speech perception especially in noisy conditions. Recent neuroimaging studies tentatively suggest that speech reading activates speech motor system, which then influences superior-posterior temporal lobe auditory areas via an efference copy. Here, nineteen healthy volunteers were presented with silent videoclips of a person articulating Finnish vowels /a/, /i/ (non-targets), and /o/ (targets) during event-related functional magnetic resonance imaging (fMRI). Speech reading significantly activated visual cortex, posterior fusiform gyrus (pFG), posterior superior temporal gyrus and sulcus (pSTG/S), and the speech motor areas, including premotor cortex, parts of the inferior (IFG) and middle (MFG) frontal gyri extending into frontal polar (FP) structures, somatosensory areas, and supramarginal gyrus (SMG). Structural equation modelling (SEM) of these data suggested that information flows first from extrastriate visual cortex to pFS, and from there, in parallel, to pSTG/S and MFG/FP. From pSTG/S information flow continues to IFG or SMG and eventually somatosensory areas. Feedback connectivity was estimated to run from MFG/FP to IFG, and pSTG/S. The direct functional connection from pFG to MFG/FP and feedback connection from MFG/FP to pSTG/S and IFG support the hypothesis of prefrontal speech motor areas influencing auditory speech processing in pSTG/S via an efference copy.

The influence of reading motives on the responses after reading blogs.

As the number of blogs increases dramatically, these online forums have become important media people use to share feelings and information. Previous research of blogs focuses on writers (i.e., bloggers), but the influence of blogs also requires investigations from readers' perspectives. This study therefore explores motives for reading blogs and discusses their effects on the responses after reading blogs. According to a factor analysis of 204 respondents in Taiwan, motives for reading blogs consist of affective exchange, information search, entertainment, and getting on the bandwagon. A regression analysis suggests the effects of these motives on three major responses--opinion acceptance, interaction intentions, and word-of-mouth (WOM) intentions--reflect the influence of blogs. Specifically, readers who focus on affective exchanges believe blog messages, interact with bloggers, and spread messages to others. Information search and entertainment motives positively affect opinion acceptance; blog readers who focus on information and those who read for fun both view blogs as trustworthy sources. Getting on the bandwagon also positively influences interaction and WOM intentions; these readers interact with bloggers and transmit messages to others.