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Biomimetic materials with complicated structures inspired by natural plants play a critical role in tissue engineering. The succulent plants, with complicated morphologies, show tenacious vitality in extreme conditions due to the physiological functions endowed by their unique anatomical structures. Herein, inspired by the macroscopic structure of succulent plants, succulent plant-like bioceramic scaffolds were fabricated via digital laser processing 3D printing of MgSiO3. Compared with conventional scaffolds with interlaced columns, the structures could prevent cells from leaking from the scaffolds and enhance cell adhesion. The scaffold morphology could be well regulated by changing leaf sizes, shapes, and interlacing methods. The succulent plant-like scaffolds show excellent properties for cell loading as well as cell distribution, promoting cellular interplay, and further enhancing the osteogenic differentiation of bone marrow stem cells. The in vivo study further illustrated that the succulent plant-like scaffolds could accelerate bone regeneration by inducing the formation of new bone tissues. The study suggests that the obtained succulent plant-like scaffold featuring the plant macroscopic structure is a promising biomaterial for regulating cell distribution, enhancing cellular interactions, and further improving bone regeneration. [ABSTRACT FROM AUTHOR]

Osteochondral defect (OCD) regeneration remains a great challenge. Recently, multilayer scaffold simulating native osteochondral structures have aroused broad interest in osteochondral tissue engineering. Here, we developed a 3D multifunctional bi-layer scaffold composed of a kartogenin (KGN)-loaded GelMA hydrogel (GelMA/KGN) as an upper layer mimicking a cartilage-specific extracellular matrix and a hydroxyapatite (HA)-coated 3D printed polycaprolactone porous scaffold (PCL/HA) as a lower layer simulating subchondral bone. The bi-layer scaffolds were subsequently modified with tannic acid (TA) prime-coating and E7 peptide conjugation (PCL/HA-GelMA/KGN@TA/E7) to regulate endogenous stem cell behaviors and exert antioxidant activity for enhanced osteochondral regeneration. In vitro, the scaffolds could support cell attachment and proliferation, and enhance the chondrogenic and osteogenic differentiation capacity of bone marrow-derived mesenchymal stem cells (BMSCs) in a specific layer. Besides, the incorporation of TA/E7 significantly increased the biological activity of the bi-layer scaffolds including the pro-migratory effect, antioxidant activity, and the maintenance of cell viability against oxidative stress. In vivo, the developed bi-layer scaffolds enhanced the simultaneous regeneration of cartilage and subchondral bone when implanted into a rabbit OCD model through macroscopic, micro-CT, and histological evaluation. Taken together, these investigations demonstrated that the 3D multifunctional bi-layer scaffolds could provide a suitable microenvironment for endogenous stem cells, and promote in situ osteochondral regeneration, showing great potential for the clinical treatment of OCD. [ABSTRACT FROM AUTHOR]

Boronic acids reversibly and covalently bind to Lewis bases and polyols, which facilitated the development of a large number of chemical sensors to recognize carbohydrates, catecholamines, ions, hydrogen peroxide, and so on. However, as the binding mechanism of boronic acids and analytes is not very clear, it is still a challenge to discover sensors with high affinity and selectivity. In this review, boronic acid sensors with two recognition sites, including diboronic acid sensors, and monoboronic acid sensors having another group or binding moiety, are summarized. Owing to double recognition sites working synergistically, the binding affinity and selectivity of sensors can be improved significantly. This review may help researchers to sort out the binding rules and develop ideal boronic acid-based sensors. [ABSTRACT FROM AUTHOR]

Herein, several boronic acid-based sensors were reported selectively recognizing D -sorbitol in aqueous solution. The fluorescence of sensor 15c was enhanced by 1.5-fold when combined with a low concentration of D -sorbitol (8.88 μM), and the fluorescence enhanced by 0.6-fold after binding to D -fructose, while it did not change obviously when combined with other carbohydrates, including D -arabinose, D -galactose, D -mannose, D -ribose, D -maltose, D -xylose, D -glucose and D -glucosamine. Fluorescence tests were carried out in DMSO/PBS (pH 9, 0.1 M) solution (1 : 99, v/v), at room temperature, which indicated that the sensors are water-soluble. In addition, competition studies showed that sensor 15c works well as a D -sorbitol-specific fluorescence sensor in both the absence and presence of carbohydrate interferents. And sensor 15c has a high binding constant (10 922 ± 776 M−1) and a low limit of detection (6.91 × 10−7 M) at pH 9 among the investigated sensors toward D -sorbitol. Furthermore, sensor 15c was applied to the analysis of real samples (D -sorbitol for oral administration). These studies indicated that sensor 15c may serve as a potential tool to detect the content of D -sorbitol in drugs and food products. [ABSTRACT FROM AUTHOR]

Boronic acids have been widely developed as fluorescent sensors for recognition of carbohydrates, especially d-glucose, ions, catechol compounds and so on. However, few d-ribose selective boronic acid sensors have been reported, and their poor water solubility brings a lot of inconvenience to their applications. Herein we report a novel water-soluble sensor, (4-(4-((3-boronobenzamido)propyl)carbamoyl)quinolin-2-yl)boronic acid (sensor 6). The fluorescence of sensor 6 decreased by 50% when combined with 0.0146 M of d-ribose, while it increased when combined with d-mannose, d-galactose, d-fructose, d-glucosamine, sialic acid, d-sorbitol and d-arabinose, and fluorescence change was not obvious after binding to d-glucose. Therefore, this sensor may serve as a fluorescence quenching sensor for d-ribose. By processing the fluorescence binding data using the Benesi–Hildebrand equation, we found that the reciprocal of fluorescence intensity quenching showed a good linear relationship with the reciprocal of d-ribose concentration, indicating that the binding ratio of sensor 6 to d-ribose is 1 : 1. In pH titration experiments, the quenched fluorescence was most pronounced at pH 7.4, indicating that the sensor may serve to recognize d-ribose at physiological pH 7.4. Subsequently, d-ribose can also cause sensor fluorescence quenching in rabbit plasma and the rabbit plasma fluorescence interference can be excluded. These studies indicate that sensor 6 is a promising tool for detecting d-ribose. [ABSTRACT FROM AUTHOR]

Simultaneous therapy and regeneration of bone tumor-induced defects still remain to be a significant challenge. Conventional therapy strategy by implanting bone graft materials can regenerate the bone defects after surgery but cannot kill residual tumor cells. In this study, we successfully prepared a 3D-printed β-tricalcium phosphate bioceramic scaffold with surface modification of Fe3O4 nanoparticles/graphene oxide nanocomposite layers (named β-TCP–Fe–GO). The prepared β-TCP–Fe–GO scaffolds possess a highly ordered macroporous structure with triangle pore morphology and a pore size of around 300–500 μm. The struts of β-TCP–Fe–GO scaffolds were uniformly deposited with Fe3O4/GO sandwich-like composite layers in which nano-sized Fe3O4 particles were wrapped by GO sheets. The Fe3O4 content in the β-TCP–Fe–GO scaffolds can be effectively modulated by controlling the coating times; the final content of Fe3O4 in β-TCP–8Fe–GO scaffolds is no more than 1% after coating 8 times. Such low content of Fe3O4 in the scaffolds endows them with super paramagnetic behavior and hyperthermal effects. The temperature of the scaffolds can be modulated in the range 50–80 °C under an alternating magnetic field for 15 minutes by controlling the magnetic intensity and Fe3O4 content. The excellent hyperthermal effect of β-TCP–Fe–GO scaffolds induced more than 75% cell death for osteosarcoma cells (MG-63) in vitro. Furthermore, the β-TCP–Fe–GO scaffolds significantly enhanced alkaline phosphatase (ALP) activity and osteogenic gene expression, such as OPN, Runx2, OCN and BSP, of rabbit bone marrow stromal cells (rBMSCs) and significantly stimulated rBMSCs proliferation as compared to pure β-TCP scaffolds by the synergistic effect of GO and the released Fe ions. Therefore, the prepared β-TCP–Fe–GO scaffolds possess prominent magnetothermal ability and excellent bone-forming activity. This study is believed to pave the way for the design and fabrication of novel tissue engineering scaffolds in a combination of therapy and regeneration functions. [ABSTRACT FROM AUTHOR]

Boronic acid provides faster fluorescence response to Fe 3+ compared to other reported sensors, which is critical for continuous dynamic detection. Herein, we reported a novel boronic acid-based sensor 4 that could recognize Fe 3+ ion in real time. After 10 equiv. of Fe 3+ ion (1 mM) was added, the fluorescence of sensor 4 was immediately quenched by 96%. While other ions, including Ba 2+ , Ca 2+ , Cr 2+ , Cd 2+ , Co 2+ , Cs 2+ , Cu 2+ , Fe 2+ , K + , Li + , Mg 2+ , Mn 2+ , Na + , Ni 2+ or Zn 2+ , respectively, did not change the fluorescence significantly. Further tests indicated that the high selectively sensing Fe 3+ ion benefits from the two boronic acid functionalities in the structure. Moreover, interference experiments showed this sensor has an excellent anti-interference ability. In addition, we performed binding activity test in rabbit plasma and other real samples for practical applications, obtaining similar results. And the thin layer loading sensor 4 was also successfully applied to recognize Fe 3+ ion among various ions. Therefore, 4 may serve as a potential sensor for continuous monitoring and detecting Fe 3+ ion in real time., Competing Interests: The authors confirm that this article content has no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Simultaneous therapy and regeneration of bone tumor-induced defects still remain to be a significant challenge. Conventional therapy strategy by implanting bone graft materials can regenerate the bone defects after surgery but cannot kill residual tumor cells. In this study, we successfully prepared a 3D-printed β-tricalcium phosphate bioceramic scaffold with surface modification of Fe 3 O 4 nanoparticles/graphene oxide nanocomposite layers (named β-TCP-Fe-GO). The prepared β-TCP-Fe-GO scaffolds possess a highly ordered macroporous structure with triangle pore morphology and a pore size of around 300-500 μm. The struts of β-TCP-Fe-GO scaffolds were uniformly deposited with Fe 3 O 4 /GO sandwich-like composite layers in which nano-sized Fe 3 O 4 particles were wrapped by GO sheets. The Fe 3 O 4 content in the β-TCP-Fe-GO scaffolds can be effectively modulated by controlling the coating times; the final content of Fe 3 O 4 in β-TCP-8Fe-GO scaffolds is no more than 1% after coating 8 times. Such low content of Fe 3 O 4 in the scaffolds endows them with super paramagnetic behavior and hyperthermal effects. The temperature of the scaffolds can be modulated in the range 50-80 °C under an alternating magnetic field for 15 minutes by controlling the magnetic intensity and Fe 3 O 4 content. The excellent hyperthermal effect of β-TCP-Fe-GO scaffolds induced more than 75% cell death for osteosarcoma cells (MG-63) in vitro. Furthermore, the β-TCP-Fe-GO scaffolds significantly enhanced alkaline phosphatase (ALP) activity and osteogenic gene expression, such as OPN, Runx2, OCN and BSP, of rabbit bone marrow stromal cells (rBMSCs) and significantly stimulated rBMSCs proliferation as compared to pure β-TCP scaffolds by the synergistic effect of GO and the released Fe ions. Therefore, the prepared β-TCP-Fe-GO scaffolds possess prominent magnetothermal ability and excellent bone-forming activity. This study is believed to pave the way for the design and fabrication of novel tissue engineering scaffolds in a combination of therapy and regeneration functions.

On-line concentration via Electrokinetic Supercharging (EKS) was used to enhance the sensitivity of the capillary electrophoretic separation of the four flavonoids naringenin, hesperetin, naringin and hesperidin. Separation conditions, including the background electrolyte pH and concentration, the length and choice of terminator and the electrokinetic injection time were optimized. The optimum conditions were: a background electrolyte of 30 mM sodium tetraborate (pH 9.5) containing 5% (v/v) of methanol, electrokinetic injection of the sample (130 s, -10 kV) followed by hydrodynamic injecting of 100 mM 2-(cyclohexylamino)ethanesulfonic acid (CHES) (17 s, 0.5 psi) as terminator, and separation with -20 kV. Under these conditions the four flavonoids could be separated with a sample-to-sample time of 15 min and detection limits from 2.0 to 6.8 ng mL(-1). When compared to a conventional hydrodynamic injection the sensitivity was enhanced between 824 and 1515 times which is 7.6-16 times higher than other CE methods for the on-line concentration of flavonoids. The applicability of the developed method was demonstrated by the detection of the four flavonoids in an aqueous extract of Clematis hexapetala pall.