Morphological features and mechanical properties of nanofibers scaffolds of polylactic acid modified with hydroxyapatite/CdSe for wound healing applications.

Ternary nanocomposites, including graphene oxide (GO), hydroxyapatite (HAP), and cadmium selenite (CdSe) have been encapsulated into nanofibrous scaffolds of polylactic acid. These compositions were indexed as HAP@PLA (C1), CdSe@PLA (C2), HAP/CdSe@PLA (C3), HAP/GO@PLA (C4), and HAP/CdSe/GO@PLA (C5). Structural confirmation is executed by XRD and XPS techniques, while FESEM performs morphological characteristics. CdSe and GO dopants cause a significant increase in nanofiber diameter, HAP/GO@PLA (C4), showing thin surface fibers with fiber diameter up to 3.1 µm, followed by HAP/CdSe/GO@PLA (C4) composite that belongs to filament size up to 2.1 µm. On the other hand, the mechanical properties reveal that the dual dopant composites HAP/CdSe@PLA (C3) and HAP/GO@PLA (C4) hit the maximum tensile fracture values with 1.49 ± 0.3 and 0.99 ± 0.2 MPa. Further, the ternary C5 composite represents the lowest contact angle of 86.1 ± 3.7°. The antibacterial activity increased from 32.4 ± 9.7 and 28.4 ± 6.5% to be 85.3 ± 4.6 and 88.1 ± 5.6% for C1 and C5, respectively, against both E. coli and S. aureus in dark conditions. Moreover, the antibacterial potency enhanced from 75.4 ± 7.6 to be 83.5 ± 6.5 from dark to light conditions against E. coli for the composition of PLA containing the binary composition of HAP/CdSe.

Toxicity and biodistribution assessment of curcumin-coated iron oxide nanoparticles: Multidose administration.

AIM: Iron oxide nanoparticles (IONPs) have been widely used in diagnosis, drug delivery, and therapy. However, the biodistribution and toxicity profile of IONPs remain debatable and incomplete, thus limiting their further use. We predict that coating iron oxide nanoparticles using curcumin (Cur-IONPs) will provide an advantage for their safety profile. MATERIALS AND METHODS: In this study, an evaluation of the multidose effect (6 doses of 5 mg/kg Cur-IONPs to male BALB/c mice, on alternating days for two weeks) on the toxicity and biodistribution of Cur-IONPs was conducted. KEY FINDINGS: Serum biochemical analysis demonstrated no significant difference in enzyme levels in the liver and kidney between the Cur-IONP-treated and control groups. Blood glucose level measurements showed a nonsignificant change between groups. However, the serum iron concentration was found to initially increase significantly but then decreased at 10 days after the final injection. Histopathological examination of the liver, spleen, kidneys, and brain showed no abnormalities or differences between the Cur-IONP-treated and control groups. There were no abnormal changes in mouse body weight. The biodistribution results showed that Cur-IONPs accumulated mainly in the liver, spleen, and brain, while almost no Cur-IONPs were found in the kidney. The iron content in the liver remained high even 10 days after the final injection, while the iron content in the spleen and brain had returned to normal levels by this time point, indicating their complete clearance. SIGNIFICANCE: These results are significant and promising for the further application of Cur-IONPs as theragnostic nanoparticles.

Rational Confinement of Yttrium Vanadate within Three-Dimensional Graphene Aerogel: Electrochemical Analysis of Monoamine Neurotransmitter (Dopamine).

Real-time monitoring of neurotransmitter levels is of tremendous technological demand, which requires more sensitive and selective sensors over a dynamic concentration range. As a use case, we report yttrium vanadate within three-dimensional graphene aerogel (YVO/GA) as a novel electrocatalyst for detecting dopamine (DA). This synergy effect endows YVO/GA nanocomposite with good electrochemical behaviors for DA detection compared to other electrodes. Benefiting from tailorable properties, it provides a large specific surface area, rapid electron transfer, more active sites, good catalytic activity, synergic effect, and high conductivity. The essential analytical parameters were estimated from the calibration plot, such as a limit of detection (1.5 nM) and sensitivity (7.1 µA µM-1 cm-2) with the YVO/GA sensor probe electrochemical approach. The calibration curve was fitted with the correlation coefficient of 0.994 in the DA concentration range from 0.009 to 83 µM, which is denoted as the linear working range. We further demonstrate the proposed YVO/GA sensor's applicability to detect DA in human serum sample with an acceptable recovery range. Our results imply that the developed sensor could be applied to the early analysis of dementia, psychiatric, and neurodegenerative disorders.

A dosimetric comparison of Volumetric Modulated Arc Therapy (VMAT) and High Dose Rate (HDR) brachytherapy in localized cervical cancer radiotherapy.

BACKGROUND: Cervical cancer radiotherapy is usually administrated through 3-Dimensional Conformal Radiation Therapy (3DCRT) followed by a brachytherapy (BT) boost. PURPOSE: To investigate whether Volumetric Modulated Arc Therapy (VMAT) can replace High Dose Rate (HDR) intracavitary BT boost for patients undergoing cervical cancer radiotherapy. MATERIALS AND METHODS: Computed Tomography (CT) images for ten patients with tandem and ovoids were included in this study. Target volumes, rectum, bladder, sigmoid, small bowel and both femoral heads were delineated. Two plans were carried out including (a) a BT plan optimized manually by modifying dwell time and Ir-192 source positions, (b) a VMAT plan generated using two partial arcs with 10 MV photon beam. The prescribed dose was 7 Gy. The relevant dose volume parameters (DVPs) of target volumes and OARs for the two plans were analyzed statistically using SPSS Wilcoxon Signed Rank test. RESULTS: VMAT plan showed a significant reduction of 9.1%, 9.3%, 15.4%, 14.4% and 13.1% in rectum maximum dose, rectum D2cc, bladder maximum dose, bladder D2cc and sigmoid maximum dose (P < 0.05). VMAT and BT plans showed comparable D2cc of sigmoid and small bowel maximum doses (P = 0.333 and P = 0.646). On the other hand, VMAT showed significantly higher small bowel D2cc and maximum point dose for both femoral heads comparing to BT plan (P < 0.05). Also, VMAT plan yielded greater homogeneous target coverage compared to BT plan (P < 0.05). CONCLUSION: The study demonstrated that VMAT plan achieves significant dose reduction of rectum, bladder and sigmoid, as well as superior homogeneous target coverage compared to BT plan. On the other hand, VMAT delivers more radiation exposures to small bowel and femoral heads.

Multifunctional magnetic-gold nanoparticles for efficient combined targeted drug delivery and interstitial photothermal therapy.

Abundant efforts have recently been made to design potent theranostic nanoparticles, which combine diagnostic and therapeutic agents, for the effective treatment of cancer. In this study, we developed multifunctional magnetic gold nanoparticles (MGNPs) that are able to (i) selectively deliver the drug to the tumor site in a controlled-release manner, either passively or by using magnetic targeting; (ii) induce photothermal therapy by producing heat by near-infrared (NIR) laser absorption; and (iii) serve as contrast agents for magnetic resonance imaging (MRI) (imaging-guided therapy). The prepared MGNPs were characterized by different physical techniques. They were then coated and conjugated with polyethylene glycol (PEG) and doxorubicin (DOX) to form MGNP-DOX conjugates. The high efficacy of MGNP-DOX for combined chemo-photothermal therapy was observed both in vitro and in vivo. The effectiveness of MGNP-DOX as theranostic nanoparticles was confirmed by histopathological examination and immunohistochemical studies. Moreover, MGNP-DOX showed good potential as MRI contrast agents for guided chemo-photothermal synergistic therapy.

Improved visualization of perfusion defects by respiratory-gated SPECT: a phantom simulation study.

OBJECTIVES: Single-photon emission computed tomography ventilation/perfusion (SPECT V/Q) imaging is recommended both by the Society of Nuclear Medicine and by the European Association of Nuclear Medicine for the diagnosis of pulmonary embolism. However, respiratory motion produces image blurring and degradation of detail in the lungs. We have investigated respiratory gating of SPECT images, correcting for motion to reduce blur and improve image definition. MATERIALS AND METHODS: Wedge-shaped defects of different sizes ranging from 15 to 4 mm were fixed in the lung cavities of an anthropomorphic lung phantom to simulate perfusion defects. Gated and nongated SPECT images were obtained using a double-headed SPECT system. Three-dimensional movement was introduced using a purpose-built moving platform with two motion frequencies of 10 and 20 cycles/min. Motion was tracked with a respiratory-gating system. Gated SPECT data were acquired in 16 discrete data bins in synchronization with the breathing cycle. The images were reconstructed using ordered-subset expectation maximization algorithms and corrected for rigid motion. Contrast and contrast-to-noise ratios (CNRs) were measured to quantify any improvement in the gated motion-corrected images. Visualization of defects in the reconstructed images was performed by seven observers and analyzed using alternative free-response receiver operating characteristic analysis. RESULTS: Assessment of gated and nongated SPECT phantom images demonstrated that motion adversely affected the detectability of defects. Quantification of data demonstrated that, in the controlled simulation, image quality, defect definition, observer confidence, contrast, and CNR were increased after applying motion correction. Improvement in CNRs was found to be significant using alternative free-response receiver operating characteristic analysis (P=0.0002). CONCLUSION: Respiratory-gated motion-corrected SPECT images enhanced the visualization of defects compared with matched moving/nongated images in a realistic moving phantom. This approach may be particularly valuable for SPECT V/Q imaging and may improve the diagnosis of pulmonary embolism.