Bendtsenmcmahan8288

The results indicate that 0.2 μg/mL of Dox in the combination of 22.5 pM of the nano-conjugate can kill 80% cancer cells, which effectively improves the treatment efficiency compared with the nano-conjugate or Dox alone based on the synergism effect (the combination index less then 1). SD-208 purchase More importantly, our developed strategy can be used for sensitizing the MDR cancer cells to the traditional ineffective drugs, which owns potential applications in decreasing the chance of MDR development and overcoming drug-resistant cancers.A novel and simple strategy was designed for the synthesis of an unmodified gum arabic (GA) and acrylic acid (AA) based polymer hydrogels using Fe3+ as a physical cross-linking agent. The hydrogels showed a high mechanical strength, self-sustainability and self-healing ability, which depends on the content of GA and Fe3+ in the composition. The fracture stress increased from 0.23 to 0.841 MPa and a decrease in self-healing from 53 to 34% was observed by increasing the GA amount from 12 to 50% respectively. The self-healing performance of the hydrogels enhanced with the existence of the Fe3+ amount on the interface. Therefore, the 3% addition of Fe3+, increased the self-healing ability of up to 70%. Furthermore, the hydrogels also showed an excellent fatigue resistance up to 20 cycles without any rapture and can beard a load of 2.5 kg for a very long time. After 4 min of resting time, the percent recovery in dissipated energy reaching a high value of 95%, indicating the excellent fatigue resistance performance of the hydrogels. The hydrogels contain 3-5% of water at normal conditions and confirm its environmental stability. This work provides a new direction for the synthesis of unmodified GA based physically cross-linked polymer hydrogels systems and can be applied in bioengineering and robotic science in the future.Aqueous dispersibility of graphene oxide (GO) sheets can be improved through enrichment of oxygen content (oxidation). However, the resulting 'oxygen clusters' are accompanied with numerous point defects, depletive to π-π stacking behavior of sheets. In this work, we have investigated the properties of sheets oxidized with 2, 4, 6, 8, 10 and 12 weight equivalents of KMnO4. Sheets were characterized by spectroscopic, X-ray diffraction (XRD) and electron microscopic techniques. Paclitaxel (PLX) was used as a model drug to analyze the changes in the loading efficiency at different levels of oxidation. Density of oxygen clusters increased as we shifted across increasing proportion of KMnO4. This was accompanied with increased inter-layer spacing, disruption of pure graphitic domains and changes in hybridization of carbon atoms (sp2 to sp3). However, these defects exhibited the tendency of saturation at a finite proportion of KMnO4. Oxygen groups negatively affected the loading efficiency of sheets for PLX. Improvement in the loading efficiency of reduced GO (rGO) sheets clarified the predominant role of π-π interactions at the surface. Our study reveals that high oxidation may offset the loading potential of highly aqueous dispersible GO sheets. Therefore, the extent of oxidation must be tuned taking into account the availability of H-bond forming groups in the drug molecule.Hydrophilic matrix tablets are the most commonly used dosage forms to fabricate oral controlled-release systems. It is highly desirable to design delivery system with novel mechanism to achieve sustained drug release through a simplified preparation process. The chitosan-anionic polymers based matrix tablets is assumed to produce self-assembly in the gastrointestinal tract, then transferring into film-coated tablets from original matrix type. But its dynamic behavior during dissolution process and the on-going internal microstructural changes during drug release were still in the dark. In this study, by using synchrotron radiation X-ray micro-tomography (SR-μCT) with phase contrast imaging, the micro-structure characteristics of chitosan-λ-carrageenan (CS-λ-CG) matrix based tablets during the dissolution were successfully elucidated for the first time. The qualitative and quantitative analyses of intensity distribution distinguished a hydrated CS-λ-CG layer from a solid core. Visualization based on 3D models ovide a novel drug release mechanism. Based on the structure feature obtained from the high contrast image, different hydration region was distinguished and the cross-linked film was identified and visualized directly for the first time.Highly porous sodium geopolymer structures were successfully produced through the chemical direct foaming approach at ambient temperature. The impact of the thermal treatment, as well as the influence of various additions of hydrogen peroxide, as a foaming agent, on the porosity, microstructure and mechanical characteristics of the produced geopolymers was investigated. The evaluation of bioactivity was carried out by assessing the formation of an apatite layer on the samples' surface, using scanning electronic microscopy and inductively coupled plasma spectrometry for the simulated body fluid solution, in which the geopolymer samples were kept up to 28 days. In addition, the biodegradability was estimated through the weight change of the samples and pH-measurements. The results demonstrated that the geopolymer foams, produced using 4.5 vol% H2O2 and heat-treated at 500 °C for 1 h, possessed a high open porosity (71 vol %), excellent compressive strength (3.56 ± 0.27 MPa), and suitable chemical stability. The pH value of SBF solutions, in which these geopolymers were immersed for 28 days, remained close to the physiological one. The in vitro study indicated that the developed geopolymer foams possessed bioactivity, as demonstrated by the formation of apatite particles on their surface after immersion in the simulated body fluid solution for 28 days.In stomatology, the promotion of alveolar bone regeneration while preventing the reduction of ridge absorption remains a challenge. In this work, we designed and prepared bio-mimetic polysaccharide hydrogels that are multi-functional in terms of being injectable, promote self-healing, degradable, porous structure, et al. After introducing nano-hydroxyapatite particles, the composite scaffold of hydrogel/hydroxyapatite (GH) stent was obtained. When GH material was injected into the mandibular incisors of rats following tooth extraction, the new bone area was enhanced more than 50%, while the alveolar ridge was promoted in excess of 60% after 4 weeks. What's more, the wound soft tissue was healed within 1 week. Overall, our results indicate that this optimized GH stent has the potential to both maintain dimensional alveolar ridge, as well as to promote soft tissue healing. Moreover, using the hydroxyapatite-containing hydrogel platform has the potential to promote bone and soft tissue regeneration.