查看更多>>摘要：Multimodal imaging-guided chemo-photothermal therapy is an excellent cancer treatment,which can not only efficiently against tumor,but also can offer precise treatment window and real-time monitoring of the treatment efficiency.In our work,polydopamine (PDA)-coated gold nanobones (AuNBs@PDA nanocomplexes) were designed for this approach.The AuNBs@PDA nanocomplexes have strong absorbance in the near infrared (NIR) region and higher photothermal conversion efficiency (75.48 ％) than gold nanobones alone,which was facilitated for photoacoustic imaging and photothermal therapy.Besides,the loading efficiency of doxorubicin (DOX) by AuNBs@PDA nanocomplexes could be up to about 70 ％ and DOX release from AuNBs@PDA/DOX nanocomplexes sensitively response to the lower pH environment and NIR laser irradiation,which makes them become the excellent nano-carrier for the delivery of chemotherapy drug.In vitro and in vivo studies showed significant cytotoxicity and antitumor efficacy by the AuNBs@PDA/DOX nanoplatform with negligible side effects.Meanwhile,the nanoplatform was also successfully employed for computed tomography (CT) imaging,attributing to the high atomic number and high X-ray attenuation coefficient of gold.Therefore,we believed that the proposed PDA-coated gold nanobones would be a novel multifunctional theranostic nanoagent to realize the PA/CT imaging-guided chemo-photothermal therapy of cancer.
查看更多>>摘要：The aim of the current study is to report an inherently radiopaque drug-eluted beads (DEBs) as promising embolic materials for TACE techniques.Firstly,the synthesized radiopaque iodinated polycaprolactone-polyurethanes (Ⅰ-PCLUs) are synthesized by chain-extending method by using 4,4-isopropylidinedi-(2,6-diiodophenol) (IBPA) as the radiopacifying agent.Then,doxorubicin (Dox) is introduced as a chemotherapeutic agent into Ⅰ-PCLU beads via a double emulsification (W/O/W) method.The drug loading and controlled release behavior of two ratios of Ⅰ-PCLU/Dox are found to be dependent upon the internal porous microstructure,and the radiopacity is well-retained after four weeks drug release.Besides,the Ⅰ-PCLU/Dox beads exhibit positive in vitro anti-tumor effect.The in vivo intramuscular implantation and liver embolization results demonstrate that Ⅰ-PCLU beads have good histocompatibility,occlusion effect and X-ray traceability.Furthermore,the drug-loaded Ⅰ-PCLU beads are performed into a VX2 rabbit hepatocellular carcinoma (HCC) model using a micro-catheter,form embolization of hepatic arteries and inhibit the tumor growth after one week post-injection.Hence,this polymeric system provides a potential radiopaque chemoembolization candidate for HCC and other cancer therapies,which could bring opportunities to the next generation of multifunctional embolic agents.
查看更多>>摘要：Dendron-polymer-based nanoscale and stimuli-responsive drug delivery systems have shown great promise in tumor-targeting accumulation without significant toxicity.Here we report a dendronized polymer-doxorubicin (DOX) hybrid (DPDH) with an improved in vivo drug delivery efficiency for cancer therapy compared with a linear polymer-DOX conjugate (LPDC).The in vitro drug release profile of DOX indicates that DPDH displays pH-responsive drug release due to cleavage of hydrazone bonds since a greater amount of DOX is released at pH 5.2 at a faster rate than at pH 7.4.DPDH efficiently enters 4T1 cells and releases DOX to induce cytotoxicity and apoptosis.Owing to the dendronzied structure,DPDH has a significantly longer blood circulation time than LPDC.DPDH substantially enhances the therapeutic efficacy to suppress tumor growth in a 4T1 mammary cancer model than LPDC as well as free drug,evidenced from tumor growth inhibition,TUNEL assessment and histological analysis.Biosafety of DPDH is also confirmed from hemolysis,body weight shifts during treatment and pathological analysis.This study demonstrates the use of dendronized polymer-DOX hybrids for specific drug molecules is a promising approach for drug delivery.
查看更多>>摘要：Micro/nanobubbles for use as ultrasound contrast agents have been fabricated with different shell materials.When various biomedical nanoparticles have been embedded in the shells of bubbles,the composite structures have shown promising applications in multi-modal imaging,drug/gene delivery,and biomedical sensing.In this study,we developed a new gas-liquid interface self-assembly method to prepare magnetic nanobubbles embedded with superparamagnetic iron oxide nanoparticles (SPIONs).The diameter of the generated assembled nanobubbles was 227.40 ± 87.21 nm with a good polydispersity index (PDI) of 0.29.Under the condition of 150 compression cycles,the nanobubble concentration could reach about 6.12 × 109/mL.Transmission electron microscopy (TEM) and scanning electronic microscopy (SEM) demonstrated that the assembled nanobubbles had a hollow gas core with SPIONs adsorbed on the surface.Ultrasound (US) imaging and magnetic resonance imaging (MRI) experiments indicated that the assembled magnetic nanobubbles exhibited good US and MR contrast capabilities.Moreover,the assembled magnetic nanobubbles were used to label neural stem cells under ultrasound exposure.After 40 s US exposure,the magnetic nanobubbles could be delivered into cells with 2.80 pg Fe per cell,which could be observed in the intracellular endosome by TEM.Compared with common incubation methods,the ultrasound exposure method did not introduce the potential cytotoxicity of transfection reagents and the efficiency was about twice as high as the efficiency of incubation.Therefore,the assembled magnetic nanobubbles prepared through the pressure-driven gas-liquid interface assembly approach could be a potential US/MRI dual model imaging nanocarrier for regenerative applications.
查看更多>>摘要：The present study aimed to formulate triptorelin acetate (TA) into poly (D,L-lactic-co-glycolic) acid (PLGA) based injectable sustained-release microspheres (TA-PLGA-MS) by usingdouble emulsion solvent extraction/evaporation (DESE) technique and investigate the effects of various material attributes and process parameters on the quality attributes such as size,shape,surface morphology,encapsulation efficiency (EE) and in vitro release behavior of these microspheres.Variable compositions of the outer water phase,type of the organic solvents,volume ratios of inner water phase to oil phase,PLGA concentrations,and the powers for emulsification in the preparation of the microspheres showed an influence on their quality attributes.An optimal formulation (F-2) obtained from this univariate approach possess an excellent EE value of 63.5％ ± 3.4％ and an average volumetric particle size of 35.3 ± 1.8 μm.This formulation was further accomplished with different solidification rates assisted by variable incubation temperatures,which exhibited an impact on the shape/surface and inner morphology of the microspheres.The resultant microspheres also displayed different in vitro release patterns.The matrices processed with a high incubation temperature conferred the fastest and the most complete drug release profile over the period of 63 days.Thus,the solidification rate could be identified as one of the critical process parameters that affected the quality of the PLGA based injectable microspheres specifically designed for the prolonged delivery of TA.
查看更多>>摘要：In this study,perforated cannulated magnesium (Mg) hip stents were fabricated via modified Mg injection molding and conventional machining,respectively.Additionally,the stent canal was filled with paraffin to simulate injection of biomaterials.The microstructure,mechanical performance,corrosion behavior,and biocompatibility were comparably studied.Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed higher affinity of interstitial element such as oxygen and carbon as consequences of routine molding process.After immersion in SBF,machining stents showed reduced degradation rate and increased deposition of calcium phosphate compared to molding stents.Corrosion resistance was improved via paraffin-filling.Consistently,the hemolysis and in vitro osteoblast cell culture models showed favourable biocompatibility in machining stents compared to molding ones,which was improved by paraffin-filling treatment as well.These results implied that the feasibility of the prepared machining stents as the potential in vivo orthopaedic application where slower degradation is required,which could be enhanced by designing canal-filling injection of biomaterials as well.
Se Heang OhJune-Ho ByunSo Young ChunYoung-Joo Jang...
161-171页
查看更多>>摘要：Although bone defects can be restored spontaneously,bone reconstruction with sufficient strength and volume continues to be a challenge in clinical practices.In recent years,the use of a variety of biomaterials with bioactivity has been attempted to compensate for this limitation.Herein,we fabricated a pDNA (encoding for BMP-2)-loaded asymmetrically porous polycaprolactone (PCL)/Pluronic F127 membrane as a bioactive guided bone regeneration (GBR) membrane,using a modified immersion-precipitation method.It was observed that the GBR membrane allows continuous release of pDNA for more than 20 weeks.The pDNA was sufficiently transfected into human bone marrow stem cells (hBMSCs) without significant cytotoxicity and the gene-transfected cells showed prolonged synthesis of BMP-2.From in vitro osteogenic differentiation and in vivo animal studies,the effective induction of osteogenic differentiation of hBMSCs and enhanced bone regeneration by the pDNA-loaded asymmetrically porous PCL/Pluronic F127 membrane was observed,suggesting that the pDNA-loaded membrane as a bioactive GBR membrane can be an alternative therapeutic technique for effective bone regeneration.
查看更多>>摘要：Localized and sustained osteogenic-angiogenic stimulation to bone defects is critical for effective bone repair.Here,desferrioxamine (DFO) was loaded on silk fibroin nanofibers and blended with hydroxyapatite nanorods (HA),forming injectable DFO-loaded silk fibroin-HA nanocomposite hydrogels.The composite hydrogels remained homogeneous distribution of HA with high ratio (60 ％) and also higher stiffness than that of pure silk fibroin nanofiber hydrogels,which provided stable osteogenic stimulation niches for tissue regeneration.Without the scarify of injectability,the hydrogels achieved slow delivery of DFO for above 60 days,resulting in suitable angiogenesis in vitro and in vivo and better osteogenesis than DFO-free systems.Compared to previous injectable silk fibroin-HA hydrogels,the introduction of vascularization capacity further stimulated the osteogenic differentiation of stem cells and accelerated new bone formation.Quicker and better bone healing were detected at defect sites after the injection of DFO-loaded nanocomposite hydrogels,indicating the effective synergistic effect of osteogenic and angiogenic cues.This work provides a simple and effective strategy of introducing angiogenic cues to bone matrices.We believe that the injectable nanocomposite hydrogels are suitable for the regeneration of bone tissues.
查看更多>>摘要：The dityrosine crosslink plays a vital role in improving mechanical property and stability of polymers,which has been found in most insects.It has also been exploited in new synthetic materials.Therein,the photochemical method provides a path for the formation of dityrosine bonding and shows its unique superiority.Here,we review different photo-innitiation approaches that generate the dityrosine link.This review may offer new strategies for photo-activated tyrosine unit manipulation.
查看更多>>摘要：The accumulation of pesticide residues in the environment due to their persistence and stability is causing increasing health concern.Indeed,researchers have rekindled their interest in eliminating pesticides from the environment by a range of biological and chemical approaches.In particular,graphene oxide (GO) has drawn great attention because it impressively enhances adsorption of pesticides in aqueous solutions,which provides promising environmental applications on water purification to remove pesticide residuals.However,although multiple studies have highlighted the adsorption of environmental contaminants by GO,the underlining molecular mechanisms remain limited.Consequently,we further delved into the knowledge regarding their adsorption molecular mechanism that is of both practical and theoretical importance.It was revealed that the π-π stacking and van der Waals interactions accounted for the major adsorption interactions between GO and its removing pesticides through integrating both density functional theory (DFT) calculation,fully atomistic molecular dynamics (MD) simulation,and binding free energy calculation.These findings not only bridged the theoretical gap of the adsorption mechanisms of GO,but also provided a venue for visualizing the adsorption process,which were essential for guiding its future adsorption applications.
NETL
NSTL
维普
万方数据