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1.
ACS Nano ; 18(28): 18522-18533, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38963059

ABSTRACT

The abuse or misuse of antibiotics in clinical and agricultural settings severely endangers human health and ecosystems, which has raised profound concerns for public health worldwide. Trace detection and reliable discrimination of commonly used fluoroquinolone (FQ) antibiotics and their analogues have consequently become urgent to guide the rational use of antibiotic medicines and deliver efficient treatments for associated diseases. Herein, we report a wearable eye patch integrated with a quadruplex nanosensor chip for noninvasive detection and discrimination of primary FQ antibiotics in tears during routine eyedrop treatment. A set of dual-mode fluorescent nanoprobes of red- or green-emitting CdTe quantum dots integrated with lanthanide ions and a sensitizer, adenosine monophosphate, were constructed to provide an enhanced fluorescence up to 45-fold and nanomolar sensitivity toward major FQs owing to the aggregation-regulated antenna effect. The aggregation-driven, CdTe-Ln(III)-based microfluidic sensor chip is highly specific to FQ antibiotics against other non-FQ counterparts or biomolecular interfering species and is able to accurately discriminate nine types of FQ or non-FQ eyedrop suspensions using linear discriminant analysis. The prototyped wearable sensing detector has proven to be biocompatible and nontoxic to human tissues, which integrates the entire optical imaging modules into a miniaturized, smartphone-based platform for field use and reduces the overall assay time to ∼5 min. The practicability of the wearable eye patch was demonstrated through accurate quantification of antibiotics in a bactericidal event and the continuous profiling of FQ residues in tears after using a typical prescription antibiotic eyedrop. This technology provides a useful supplement to the toolbox for on-site and real-time examination and regulation of inappropriate daily drug use that might potentially lead to long-term antibiotic abuse and has great implications in advancing personal healthcare techniques for the regulation of daily medication therapy.


Subject(s)
Anti-Bacterial Agents , Fluoroquinolones , Quantum Dots , Tears , Wearable Electronic Devices , Humans , Anti-Bacterial Agents/analysis , Tears/chemistry , Tears/drug effects , Fluoroquinolones/analysis , Quantum Dots/chemistry , Tellurium/chemistry , Cadmium Compounds/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Fluorescent Dyes/chemistry , Biosensing Techniques , Lab-On-A-Chip Devices
2.
Quant Imaging Med Surg ; 14(7): 4893-4902, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39022227

ABSTRACT

Background: The aggressiveness of prostate cancer (PCa) is crucial in determining treatment method. The purpose of this study was to establish a 2.5-dimensional (2.5D) deep transfer learning (DTL) detection model for the automatic detection of clinically significant PCa (csPCa) based on bi-parametric magnetic resonance imaging (bp-MRI). Methods: A total of 231 patients, including 181 with csPCa and 50 with non-clinically significant PCa (non-csPCa), were enrolled. Stratified random sampling was then employed to divide all participants into a training set [185] and a test set [46]. The DTL model was obtained through image acquisition, image segmentation, and model construction. Finally, the diagnostic performance of the 2.5D and 2-dimensional (2D) models in predicting the aggressiveness of PCa was evaluated and compared using receiver operating characteristic (ROC) curves. Results: DTL models based on 2D and 2.5D segmentation were established and validated to assess the aggressiveness of PCa. The results demonstrated that the diagnostic efficiency of the DTL model based on 2.5D was superior to that of the 2D model, regardless of whether in a single or combined sequence. Particularly, the 2.5D combined model outperformed other models in differentiating csPCa from non-csPCa. The area under the curve (AUC) values for the 2.5D combined model in the training and test sets were 0.960 and 0.949, respectively. Furthermore, the T2-weighted imaging (T2WI) model showed superiority over the apparent diffusion coefficient (ADC) model, but was not as effective as the combined model, whether based on 2.5D or 2D. Conclusions: A DTL model based on 2.5D segmentation was developed to automatically evaluate PCa aggressiveness on bp-MRI, improving the diagnostic performance of the 2D model. The results indicated that the continuous information between adjacent layers can enhance the detection rate of lesions and reduce the misjudgment rate based on the DTL model.

3.
Acta Radiol ; 65(6): 554-564, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38623640

ABSTRACT

BACKGROUND: Computed tomography (CT) radiomics combined with deep transfer learning was used to identify cholesterol and adenomatous gallbladder polyps that have not been well evaluated before surgery. PURPOSE: To investigate the potential of various machine learning models, incorporating radiomics and deep transfer learning, in predicting the nature of cholesterol and adenomatous gallbladder polyps. MATERIAL AND METHODS: A retrospective analysis was conducted on clinical and imaging data from 100 patients with cholesterol or adenomatous polyps confirmed by surgery and pathology at our hospital between September 2015 and February 2023. Preoperative contrast-enhanced CT radiomics combined with deep learning features were utilized, and t-tests and least absolute shrinkage and selection operator (LASSO) cross-validation were employed for feature selection. Subsequently, 11 machine learning algorithms were utilized to construct prediction models, and the area under the ROC curve (AUC), accuracy, and F1 measure were used to assess model performance, which was validated in a validation group. RESULTS: The Logistic algorithm demonstrated the most effective prediction in identifying polyp properties based on 10 radiomics combined with deep learning features, achieving the highest AUC (0.85 in the validation group, 95% confidence interval = 0.68-1.0). In addition, the accuracy (0.83 in the validation group) and F1 measure (0.76 in the validation group) also indicated strong performance. CONCLUSION: The machine learning radiomics combined with deep learning model based on enhanced CT proves valuable in predicting the characteristics of cholesterol and adenomatous gallbladder polyps. This approach provides a more reliable basis for preoperative diagnosis and treatment of these conditions.


Subject(s)
Deep Learning , Tomography, X-Ray Computed , Humans , Female , Male , Retrospective Studies , Middle Aged , Tomography, X-Ray Computed/methods , Aged , Gallbladder/diagnostic imaging , Gallbladder Neoplasms/diagnostic imaging , Adult , Polyps/diagnostic imaging , Cholesterol , Gallbladder Diseases/diagnostic imaging , Predictive Value of Tests , Adenomatous Polyps/diagnostic imaging , Machine Learning , Contrast Media , Radiomics
5.
J Sci Food Agric ; 103(7): 3447-3456, 2023 May.
Article in English | MEDLINE | ID: mdl-36812130

ABSTRACT

BACKGROUND: Chitosan (CS) and tripolyphosphate (TPP) can be combined in the development of a material with synergistic properties and promising potential for the conservation of food products. In this study, ellagic acid (EA) and anti-inflammatory peptide (FPL)-loaded CS nanoparticles (FPL/EA NPs) were prepared using the ionic gelation method and optimal preparation conditions were obtained through a single factor design. RESULTS: The synthesized nanoparticles (NPs) were characterized using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Nanoparticles were spherical, with an average size of 308.33 ± 4.61 nm, a polydispersity index (PDI) of 0.254, a zeta potential of +31.7 ± 0.08 mV, and a high encapsulation capacity (22.16 ± 0.79%). An in vitro release study showed that EA/FPL had a sustainable release from FPL/EA NPs. The stability of the FPL/EA NPs was evaluated for 90 days at 0, 25, and 37 °C. Significant anti-inflammatory activity of FPL/EA NPs was verified by nitric oxide (NO) and tumor necrosis factor-α (TNF-α) reduction. CONCLUSION: These characteristics support the use of CS nanoparticles to encapsulate EA and FPL and improve their bioactivity in food products. © 2023 Society of Chemical Industry.


Subject(s)
Chitosan , Nanoparticles , Chitosan/chemistry , Ellagic Acid , Anti-Inflammatory Agents/pharmacology , Drug Carriers/chemistry , Peptides/pharmacology , Nanoparticles/chemistry , Particle Size , Spectroscopy, Fourier Transform Infrared
8.
Front Pharmacol ; 13: 1037993, 2022.
Article in English | MEDLINE | ID: mdl-36408220

ABSTRACT

Available vaccine-based immunity may at high risk of being evaded due to substantial mutations in the variant Omicron. The main protease (Mpro) of SARS-CoV-2 and human neuropilin-1 (NRP1), two less mutable proteins, have been reported to be crucial for SARS-CoV-2 replication and entry into host cells, respectively. Their dual blockade may avoid vaccine failure caused by continuous mutations of the SARS-CoV-2 genome and exert synergistic antiviral efficacy. Herein, four cyclic peptides non-covalently targeting both Mpro and NRP1 were identified using virtual screening. Among them, MN-2 showed highly potent affinity to Mpro (K d = 18.2 ± 1.9 nM) and NRP1 (K d = 12.3 ± 1.2 nM), which was about 3,478-fold and 74-fold stronger than that of the positive inhibitors Peptide-21 and EG3287. Furthermore, MN-2 exhibited significant inhibitory activity against Mpro and remarkable anti-infective activity against the pseudotyped variant Omicron BA.2.75 without obvious cytotoxicity. These data demonstrated that MN-2, a novel non-covalent cyclic peptide, is a promising agent against Omicron BA.2.75.

9.
Food Chem (Oxf) ; 5: 100139, 2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36262383

ABSTRACT

This study aimed to isolate bioactive peptides with elastase inhibitory activity from walnut meal via ultrasonic enzymatic hydrolysis. The optimal hydrolysis conditions of walnut meal protein hydrolysates (WMPHs) were obtained by response surface methodology (RSM), while a molecular weight of<3 kDa fraction was analyzed by LC-MS/MS, and 556 peptides were identified. PyRx virtual screening and Autodock Vina molecular docking revealed that the pentapeptide Phe-Phe-Val-Pro-Phe (FFVPF) could interact with elastase primarily through hydrophobic interactions, hydrogen bonds, and π-sulfur bonds, with a binding energy of -5.22 kcal/mol. The verification results of inhibitory activity showed that FFVPF had better elastase inhibitory activity, with IC50 values of 0.469 ± 0.01 mg/mL. Furthermore, FFVPF exhibited specific stability in the gastric environment. These findings suggest that the pentapeptide FFVPF from defatted walnut meal could serve as a potential source of elastase inhibitors in the food, medical, and cosmetics industries.

10.
Anal Chim Acta ; 1206: 339809, 2022 May 08.
Article in English | MEDLINE | ID: mdl-35473868

ABSTRACT

Lanthanide coordination polymer nanoparticles (LML-Eu3+-GMP CPNPs) were fabricated as a ratiometric fluorescence sensor for real-time and visual assays of tetracycline (TC). The LML-Eu3+-GMP CPNPs were prepared by spontaneous self-assembly of Eu3+, luminol (LML) and guanosine 5'-monophosphate (GMP) at room temperature, which only emitted blue fluorescence dominated by LML, and no red characteristic fluorescence of Eu3+ was observed. In the presence of TC, TC can trigger the antenna effect (AE) and inner filter effect (IFE), the blue fluorescence of LML-Eu3+-GMP CPNPs is quenched by TC via IFE, and the red characteristic fluorescence of Eu3+ can be turned on through AE. When sodium citrate (Cit) is added to the sensing system, it can further enhance the red fluorescence of Eu3+. The dual-ligand CPNP sensor has a rapid fluorescence response, noticeable fluorescence color change, good selectivity, and high sensitivity with a detection limit of 3.4 nM. It was successfully applied to detect TC in honey, milk, lake water and tap water. Meanwhile, the portable smartphone and test paper were applied to develop POCT devices for real-time and visual detection of TC, which could offer a promising application for real-time and semiquantitative assays of TC.


Subject(s)
Heterocyclic Compounds , Lanthanoid Series Elements , Nanoparticles , Anti-Bacterial Agents/analysis , Fluorescent Dyes , Polymers , Smartphone , Spectrometry, Fluorescence , Tetracycline , Water
11.
Opt Lett ; 47(3): 678-681, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-35103706

ABSTRACT

Recently, terahertz (THz) nonreciprocal and functionality-switchable devices have drawn much attention. Here we report a magnetic-free THz unidirectional perfect absorber as well as a functionality-switchable device between the band-pass filter and perfect absorber based on dielectric-graphene multilayers containing a VO2 defect layer. We provide a theoretical explanation for the nonreciprocal transmission properties. The working frequencies of these devices can be tailored by using graphene layers of different chemical potentials.

12.
Front Vet Sci ; 8: 756910, 2021.
Article in English | MEDLINE | ID: mdl-34869730

ABSTRACT

Interaction between the dietary fiber and the gut microbes can regulate host bile acid metabolism. This study sought to explore the effects of guar gum combined with pregelatinized waxy maize starch (GCW) in a gestation diet on reproductive performance, gut microbiota composition, and bile acid homeostasis of sows. A total of 61 large white sows were randomly grouped into the control (n = 33) and 2% GCW (n = 28) groups during gestation. GCW diet increased birth-weight of piglets, and decreased the percentage of intrauterine growth restriction (IUGR) piglets. In addition, dietary GCW reduced gut microbial diversity and modulated gut microbial composition in sows on day 109 of gestation. The relative abundance of bile salt hydrolase (BSH) gene-encoding bacteria, Lactobacillus and Bacteroides decreased after GCW administration, whereas no significant difference was observed in the fecal level of total glycine-conjugated and taurine-conjugated bile acids between the two groups. Dietary GCW increased the relative abundance of Ruminococcaceae (one of few taxa comprising 7α-dehydroxylating bacteria), which was associated with elevated fecal deoxycholic acid (DCA) in the GCW group. GCW administration lowered the concentrations of plasma total bile acid (TBA) and 7α-hydroxy-4-cholesten-3-one (C4) (reflecting lower hepatic bile acid synthesis) at day 90 and day 109 of gestation compared with the control diet. Furthermore, the levels of plasma glycoursodeoxycholic acid (GUDCA), tauroursodeoxycholic acid (TUDCA) and glycohyocholic acid (GHCA) were lower in the GCW group compared with the control group. Spearman correlation analysis showed alterations in the composition of the gut microbiota by GCW treatment was associated with improved bile acid homeostasis and reproductive performance of sows. In conclusion, GCW-induced improves bile acid homeostasis during gestation which may enhance reproductive performance of sows.

13.
Front Microbiol ; 12: 686648, 2021.
Article in English | MEDLINE | ID: mdl-34512565

ABSTRACT

Systemic inflammatory response after cardiovascular surgery is associated with poor prognosis, to which gut barrier impairment is related. To investigate whether perioperative changes of the gut microbiome are associated with systemic and intestinal inflammatory response, we examined changes of the gut microbiome, intestinal homeostasis, and systemic inflammatory response in cardiovascular patients before (Pre) surgery and on the first defecation day [postoperative time 1 (Po1)] or a week [postoperative time 2 (Po2)] postsurgery. Markedly, the enhanced systemic inflammatory response was observed in Po1 and Po2 compared with that in Pre. In line with inflammatory response, impaired gut barrier and elevated gut local inflammation were observed in Po1 and Po2. Microbiome analysis showed a remarkable and steady decline of alpha diversity perioperatively. In addition, microbial composition in the postoperation period was characterized by significant expansion of Enterococcus along with a decrease in anaerobes (Blautia, Faecalibacterium, Bifidobacterium, Roseburia, Gemmiger, [Ruminococcus], and Coprococcus), which were typically health-associated bacteria. Spearman correlation analysis showed microbiome disorder was associated with enhanced systemic inflammatory response and intestinal dysbiosis. These results suggest that microbiome disorder was related to disturbed gut homeostatic and subsequently elevates plasma endotoxin and systemic inflammatory response after cardiovascular surgery. This study not only highlights gut microbiome would be considered in future clinical practice but also proposes a promising perspective of potential diagnostic and therapeutic options for perioperative management of cardiovascular surgery patients.

14.
Front Chem ; 9: 652287, 2021.
Article in English | MEDLINE | ID: mdl-33816441

ABSTRACT

Plasmonic nanostructures, particularly of noble-metal Au and Ag, have attracted long-lasting research interests because of their intriguing physical and chemical properties. Under light excitation, their conduction electrons can form collective oscillation with the electromagnetic fields at particular wavelength, leading to localized surface plasmon resonance (LSPR). The remarkable characteristic of LSPR is the absorption and scattering of light at the resonant wavelength and greatly enhanced electric fields in localized areas. In response to the chemical and physical changes, these optical properties of plasmonic nanostructures will exhibit drastic color changes and highly sensitive peak shifts, which has been extensively used for biological imaging and disease treatments. In this mini review, we aim to briefly summarize recent progress of preparing responsive plasmonic nanostructures for biodiagnostics, with specific focus on cancer imaging and treatment. We start with typical synthetic approaches to various plasmonic nanostructures and elucidate practical strategies and working mechanism in tuning their LSPR properties. Current achievements in using responsive plasmonic nanostructures for advanced cancer diagnostics will be further discussed. Concise perspectives on existing challenges in developing plasmonic platforms for clinic diagnostics is also provided at the end of this review.

15.
Medicine (Baltimore) ; 99(34): e21886, 2020 Aug 21.
Article in English | MEDLINE | ID: mdl-32846848

ABSTRACT

BACKGROUND: As the gold standard for imaging sinus disease, the main disadvantage of computed tomography (CT) of the pediatric paranasal sinus is radiation exposure. Because of this, 1 protocol for CT should reduce radiation dose while maintaining image quality. The aim of this study is to evaluate the image quality of dose-reduced paranasal sinus computed tomography (CT) using an ultralow tube voltage (70 kVp) combined with iterative reconstruction (IR) in children. METHODS: CT scans of the paranasal sinus were performed using different protocols [70 kVp protocols with IR, Group A, n = 80; 80 kVp protocols with a filtered back projection algorithm, Group B, n = 80] in 160 pediatric patients. Then, the volume-weighted CT dose index, dose-length product, and effective dose were estimated. Image noise, the signal-to-noise ratio and the diagnostic image quality were also evaluated. RESULTS: For the radiation dose, the volume-weighted CT dose index, dose-length product and effective dose values were significantly lower for the 70 kVp protocols than for the 80 kVp protocols (P < .001). Compared with the 80 kVp protocols, the 70 kVp protocols had significantly higher levels of image noise (P = .001) and a lower signal-to-noise ratio (P = .002). No significant difference in the overall subjective image quality grades was observed between these 2 groups (P = .098). CONCLUSION: The ultralow tube voltage (70 kVp) technique combined with IR enabled a significant dose reduction in CT examinations performed in the pediatric paranasal sinus while maintaining diagnostic image quality with clinically acceptable image noise.


Subject(s)
Image Enhancement/instrumentation , Paranasal Sinus Diseases/diagnostic imaging , Radiation Exposure/adverse effects , Radiographic Image Interpretation, Computer-Assisted/methods , Tomography, X-Ray Computed/instrumentation , Adolescent , Algorithms , Child , Child, Preschool , China/epidemiology , Feasibility Studies , Female , Humans , Male , Prospective Studies , Radiation Dosage , Radiation Exposure/statistics & numerical data , Signal-To-Noise Ratio
16.
Exp Ther Med ; 20(1): 367-374, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32550886

ABSTRACT

Diabetic nephropathy (DN) is one of the late complications of diabetes, which seriously affects the lives of patients. Baicalin (BA) is a flavone glycoside that has been identified to improve renal function in patients with DN. The present study aimed to investigate the roles and mechanisms of BA in DN. For that purpose, podocytes were cultured for 48 h under conditions of high glucose (HG; 30 mM D-glucose) or normal glucose (NG; 5 mM D-glucose). Then, the cells were treated with different concentrations of BA (6.25, 12.5 and 25 µM) for 24 h. Cell viability and apoptosis were determined using an MTT assay and flow cytometry, respectively. Protein and mRNA expression levels were analyzed using western blotting and reverse transcription-quantitative PCR, respectively. BA treatment was identified to promote the viability of podocytes and suppress cell apoptosis in a dose-dependent manner. Compared with the results in the NG group, HG stimulation significantly decreased the viability of podocytes and increased the apoptotic rate, whereas BA treatment following HG stimulation increased the viability of podocytes and decreased the apoptotic rate. Moreover, the effect of BA was revealed to be associated with the sirtuin 1/NF-κB signaling pathway in DN. In conclusion, the results of the present study suggested that BA treatment may significantly decrease HG-induced podocyte apoptosis, which indicated that BA might be a promising agent for DN treatment.

17.
Fundam Clin Pharmacol ; 33(6): 621-633, 2019 Dec.
Article in English | MEDLINE | ID: mdl-30951217

ABSTRACT

Felbamate is an anticonvulsant used in the treatment of epilepsy. In this study, we investigated the antidepressant-like actions of felbamate in mice. The effects of felbamate were first assessed using the forced swimming test (FST) and tail suspension test (TST), and then investigated in the chronic unpredictable mild stress (CUMS) and chronic social defeat stress (CSDS) models of depression. The changes in the hippocampal brain-derived neurotrophic factor (BDNF) signaling cascade after chronic stress and felbamate treatment were also examined. It was found that felbamate exhibited antidepressant-like activities in the FST and TST without affecting the locomotor activity of mice. Felbamate was also effective in both the CUMS and CSDS models of depression. Moreover, felbamate administration fully restored the decreased hippocampal BDNF signaling pathway in both the CUMS-stressed and CSDS-stressed mice. Collectively, felbamate has antidepressant-like actions in mice involving the hippocampal BDNF system.


Subject(s)
Antidepressive Agents/pharmacology , Depression/drug therapy , Felbamate/pharmacology , Animals , Brain-Derived Neurotrophic Factor/physiology , Disease Models, Animal , Hindlimb Suspension , Hippocampus/physiology , Male , Mice , Mice, Inbred C57BL , Motor Activity/drug effects , Receptors, N-Methyl-D-Aspartate/drug effects , Stress, Psychological/drug therapy
18.
Talanta ; 174: 14-20, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-28738560

ABSTRACT

Metal-enhanced fluorescence of fluoroquinolones (FQs) was first observed in aqueous solutions. In addition, a new type of silver nanoparticles (AgNP) was synthesized with simple and easy synthetic processes and environmentally friendly compounds. The effects of different concentrations of AgNPs on the fluorescence behaviours of ciprofloxacin (CIP), enrofloxacin (ENR) and lomefloxacin (LMF) in aqueous solutions were investigated, respectively. The experimental results demonstrated that the fluorescence peak shapes and the locations of the features in the excitation and emission spectra for each FQ that was mixed with AgNPs were almost the same as those of the standard FQs. An enhancement or quenching of the fluorescence can also be observed, depending on the exact conditions. Compared with the identical control samples that lack AgNPs, the fluorescence of each FQ in aqueous solutions was greatly enhanced by AgNPs with concentrations at a volume ratio of 5%. Moreover, at the optimum AgNP concentration, novel sensitive fluorometric methods for the separate determination of trace amounts of CIP, ENR and LMF in aqueous solutions were established. Under optimal experimental conditions, the linear dynamic ranges for the determination of CIP, ENR and LMF concentrations varied from 0.025 to 1.0mgL-1, 5.0 to 160ngL-1 and 0.01 to 0.8mgL-1, and the limits of detection were 90, 5 and 6ngL-1, respectively; the relative standard deviation was less than 1.2% (n = 9). The experimental recovery results for the determination of CIP, ENR and LMF in aqueous solutions ranged from 99% to 102%, 90% to 103% and 92% to 107%, respectively. Compared with the established method in which no AgNPs were added, the quantitation limits of the silver nanoparticle-enhanced fluorometric methods were approximately 2-fold lower for CIP, 2.6-fold lower for ENR and 4-fold lower for LMF. Significantly, the novel silver nanoparticle-enhanced fluorometric methods were successfully applied to directly determine CIP, ENR and LMF concentrations in pharmaceutical preparations, demonstrating the methods' advantages of simplicity, sensitivity and low cost.

19.
J Biomater Sci Polym Ed ; 28(1): 119-138, 2017 01.
Article in English | MEDLINE | ID: mdl-27774855

ABSTRACT

This study describes the preparation and properties of a novel aliphatic cost-effective segmented polyurethanes (SPUs) based on poly(ether ester) (poly-(ε-caprolactone-co-l-lactide)-poly(ethylene glycol)-poly-(ε-caprolactone-co-l-lactide), PECLA) and uniform-size diurethane diisocyanates (HDI-BDO-HDI). PECLA was synthesized via bulk ring-opening polymerization with poly(ethylene glycol) (PEG) as an initiator and ε-caprolactone, l-lactide as monomers. By chain extension of PECLA diol with HDI-BDO-HDI, three SPUs with different hydrophilic segments content and hard segments content were obtained. The chemical structures of the chain extender, PECLA and SPUs were confirmed by 1H NMR, 13C NMR, FT-IR, HR-TOF-MS and GPC. The influences of PEG content and uniform-size hard segments on in vitro degradability and mechanical properties of SPU films were researched. Similar thermostability observed in TGA curves of SPU films indicated that the hard segments and PEG content had little influence on the thermostability. The formation of microsphase-separated morphologies, which were demonstrated by the results of DSC and XRD, and physical-linking (H-bonds) network structures led to better mechanical properties of SPU films (ultimate stress: 23.1-17.9 MPa; elongation at break: 840-1130%). The results of water absorption and water contact angle showed that the bulk and surface hydrophilicity were closely related with the hydrophilic PEG content in SPU backbone. And the water absorption being less than 10 wt% indicated that the SPU films had low swelling property. In vitro hydrolytic degradation studies showed that the time of the SPU films becoming fragments was 34-19 days and the degradation rate increased with the increasing content of hydrophilic segments in SPUs, indicating that the degradation rate of SPU films could be controlled by adjusting PEG content. Cytotoxicity test of film extracts were conducted using L929 cells, and the relative growth rate exceeded 90% after incubation for 24, 48 and 72 h, showing excellent cytocompatibility. The acceptable mechanical properties, controllable biodegradability and excellent cytocompatibility of the polyurethanes can make them good candidates for further biomedical applications.


Subject(s)
Biocompatible Materials/chemistry , Ether/chemistry , Polyesters/chemistry , Polyethylene Glycols/chemistry , Polyurethanes/chemistry , Adsorption , Animals , Biocompatible Materials/toxicity , Cattle , Cell Line , Drug Stability , Mechanical Phenomena , Mice , Serum Albumin, Bovine/chemistry , Temperature , Water/chemistry
20.
Adv Mater ; 26(28): 4794-802, 2014 Jul 23.
Article in English | MEDLINE | ID: mdl-24838472

ABSTRACT

Red blood cells are attached to iron oxide nanoparticles pre-coated with chlorine e6, a photosensitizer, and then loaded with a chemotherapeutic drug, doxorubicin, to enable imaging-guided combined photodynamic and chemotherapy of cancer, achieving excellent synergistic therapeutic effects in an animal tumor model. This work highlights the great promise of integrating cell-based drug-delivery systems with nanotechnology as a biocompatible multifunctional platform for applications in cancer theranostics.


Subject(s)
Breast Neoplasms/pathology , Breast Neoplasms/therapy , Doxorubicin/administration & dosage , Erythrocyte Transfusion/methods , Magnetite Nanoparticles/therapeutic use , Porphyrins/administration & dosage , Animals , Cell Line, Tumor , Cell Tracking/methods , Chlorophyllides , Combined Modality Therapy/methods , Erythrocytes/chemistry , Erythrocytes/cytology , Magnetic Resonance Imaging, Interventional/methods , Mice , Mice, Inbred BALB C , Phototherapy/methods , Porphyrins/chemistry
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