scholarly journals Ultrasound-Induced Amino Acid-Based Hydrogels With Superior Mechanical Strength for Controllable Long-Term Release of Anti-Cercariae Drug

Author(s):  
Liying Ling ◽  
Lei Zhu ◽  
Yibao Li ◽  
Chunhua Liu ◽  
Linxiu Cheng

Stimulus-responsive hydrogels are significantly programmable materials that show potential applications in the field of biomedicine and the environment. Ultrasound as a stimulus can induce the formation of hydrogels, which exhibit the superior performance of different structures. In this study, we reported an ultrasound-induced supramolecular hydrogel based on aspartic acid derivative N,N′-diaspartate-3,4,9,10-perylene tetracarboxylic acid imide, showing superior performance in drug release. The results show that the driving force of this ultrasonic induced hydrogel could be attributed to hydrogen bonding and π-π interaction. The rheological and cytotoxicity test illustrate excellent mechanical properties and biocompatibility of the hydrogel. The anti-Schistosoma japonicum cercariae (CC) drug release results show large drug loadings (500 mg/ml) and long-term release (15 days) of this hydrogel. This study demonstrates that this hydrogel may serve as a slow-release platform for anti-CC.

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87422-87432 ◽  
Author(s):  
Y. Chen ◽  
W. Y. Liu ◽  
G. S. Zeng

Hybrid hydrogels (W–C gels), composed of PDMAEMA, cellulose nanowhisker (CNW) and carboxymethyl chitosan (CMCS), were prepared for developing a stimuli-responsive drug-release system.


2015 ◽  
Vol 817 ◽  
pp. 374-378 ◽  
Author(s):  
Li Qiao ◽  
Hui Huang Yang ◽  
Jian Feng Sheng

Friction-weld Cu-Al has many potential applications to replace the traditional Cu or Al conductor as it has the superior performance and low cost. For ensuring the reliability of Al/Cu metal joints, the mechanical, electrical and long-term properties were investigated by comparing the properties of Cu and Al. The results show that the mechanical properties (tension, impact and hardness) of friction-welded Cu-Al are between the values of Cu and Al, and the welding seam is not the weakest part in mechanical. The electrical resistance of Cu-Al is also between the values of Cu and Al, and does not increase after long-term vibration test and high-low temperature cycle test. The welding seaming is a weak part for salt spray test, it is better to be protected for use.


2008 ◽  
Author(s):  
George S. Yip ◽  
Timothy M. Devinney ◽  
Gerry Johnson
Keyword(s):  

2020 ◽  
Vol 16 ◽  
Author(s):  
Kannappan Panchamoorthy Gopinath ◽  
Malolan Rajagopal ◽  
Abhishek Krishnan ◽  
Shweta Kolathur Sreerama

Background: Depletion and contamination of environmental resources such as water, air and soil caused by human activities is an increasingly important challenge faced around the world. The consequences of environmental pollution are felt acutely by all living beings, both on a short and long-term basis, thereby making methods of remediation of environmental pollution an urgent requirement. Objectives: The objective of this review is to dissect the complications caused by environmental degradation, highlight advancements in the field of nanotechnology and to scrutinize its applications in environmental remediation. Furthermore, the review aims to concisely explain the merits and drawbacks of nanotechnology compared to existing methods. Conclusion: The current and potential applications of nanomaterials and nanocomposites in the prevention, control and reduction of air, water and soil pollution and the mechanisms involved have been elucidated, as have their various merits and demerits. The applications of nanotechnology in the fields of carbon capture and agriculture have also received attention in this review.


Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 13
Author(s):  
Benzion Amoyav ◽  
Yoel Goldstein ◽  
Eliana Steinberg ◽  
Ofra Benny

Microfluidics research for various applications, including drug delivery, cell-based assays and biomedical research has grown exponentially. Despite this technology’s enormous potential, drawbacks include the need for multistep fabrication, typically with lithography. We present a one-step fabrication process of a microfluidic chip for drug dissolution assays based on a 3D printing technology. Doxorubicin porous and non-porous microspheres, with a mean diameter of 250µm, were fabricated using a conventional “batch” or microfluidic method, based on an optimized solid-in-oil-in-water protocol. Microspheres fabricated with microfluidics system exhibited higher encapsulation efficiency and drug content as compared with batch formulations. We determined drug release profiles of microspheres in varying pH conditions using two distinct dissolution devices that differed in their mechanical barrier structures. The release profile of the “V” shape barrier was similar to that of the dialysis sac test and differed from the “basket” barrier design. Importantly, a cytotoxicity test confirmed biocompatibility of the printed resin. Finally, the chip exhibited high durability and stability, enabling multiple recycling sessions. We show how the combination of microfluidics and 3D printing can reduce costs and time, providing an efficient platform for particle production while offering a feasible cost-effective alternative to clean-room facility polydimethylsiloxane-based chip microfabrication.


2017 ◽  
Vol 20 (16) ◽  
pp. 2869-2877 ◽  
Author(s):  
Taren Swindle ◽  
Julie M Rutledge ◽  
Belynda Dix ◽  
Leanne Whiteside-Mansell

AbstractObjectiveChildren’s dietary intake impacts weight status and a range of short- and long-term health outcomes. Accurate measurement of factors that influence children’s diet is critical to the development and evaluation of interventions designed to improve children’s diets. The purpose of the current paper is to present the development of the Table Talk observational tool to measure early care and education teachers’ (ECET) verbal feeding communications.DesignAn observational tool to assess ECET verbal communication at mealtimes was deigned based on the extant literature. Trained observers conducted observations using the tool during lunch for both lead and assistant ECET. Descriptive statistics, test–retest for a subgroup, interclass correlations for each item, and comparisons between leads and assistants were conducted.SettingHead Start centres, Southern USA.SubjectsSeventy-five Head Start educators.ResultsOn average, 17·2 total verbal feeding communications (sd8·9) were observed per ECET. For lead ECET, the most prevalent Supportive Comment was Exploring Foods whereas for assistants Making Positive Comments was the most prevalent. Overall, lead ECET enacted more Supportive Comments than assistant ECET (F(2,72)=4·8,P=0·03). The most common Unsupportive Comment was Pressuring to Eat, with a mean of 3·8 (sd4·3) and a maximum of 25. There was no difference in Unsupportive Comments between lead and assistant ECET.ConclusionsTable Talk may be a useful tool to assess verbal feeding communications of ECET, with potential applications such as informing ECET training and assessing intervention efforts.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1165
Author(s):  
Zhanna K. Nazarkina ◽  
Boris P. Chelobanov ◽  
Konstantin A. Kuznetsov ◽  
Alexey V. Shutov ◽  
Irina V. Romanova ◽  
...  

It was previously shown that polycaprolactone (PCL)-based electrospun-produced paclitaxel (PTX)-enriched matrices exhibit long-term drug release kinetics and can be used as coatings for drug-eluting stents (DES). The installation of vascular stents involves a twofold increase in stent diameter and, therefore, an elongation of the matrices covering the stents, as well as the arterial wall in a stented area. We studied the influence of matrix elongation on its structure and PTX release using three different electrospun-produced matrices. The data obtained demonstrate that matrix elongation during stent installation does not lead to fiber breaks and does not interfere with the kinetics of PTX release. To study PTX diffusion through the expanded artery wall, stents coated with 5%PCL/10%HSA/3%DMSO/PTX and containing tritium-labeled PTX were installed into the freshly obtained iliac artery of a rabbit. The PTX passing through the artery wall was quantified using a scintillator β-counter. The artery retained the PTX and decreased its release from the coating. The retention of PTX by the arterial wall was more efficient when incubated in blood plasma in comparison with PBS. The retention/accumulation of PTX by the arterial wall provides a prolonged drug release and allows for the reduction in the dose of the drugs in electrospun-produced stent coatings.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3754 ◽  
Author(s):  
Yongji Yan ◽  
Xu Zhang ◽  
Haopeng Li ◽  
Yu Ma ◽  
Tianci Xie ◽  
...  

A novel ultraviolet (UV) optical fiber sensor (UVOFS) based on the scintillating material La2O2S:Eu has been designed, tested, and its performance compared with other scintillating materials and other conventional UV detectors. The UVOFS is based on PMMA (polymethyl methacrylate) optical fiber which includes a scintillating material. Scintillating materials provide a unique opportunity to measure UV light intensity even in the presence of strong electromagnetic interference. Five scintillating materials were compared in order to select the most appropriate one for the UVOFS. The characteristics of the sensor are reported, including a highly linear response to radiation intensity, reproducibility, temperature response, and response time (to pulsed light) based on emission from a UV source (UV fluorescence tube) centered on a wavelength of 308 nm. A direct comparison with the commercially available semiconductor-based UV sensor proves the UVOFS of this investigation shows superior performance in terms of accuracy, long-term reliability, response time and linearity.


1994 ◽  
Vol 131 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Josef Marek ◽  
Václav Hána ◽  
Michal Kršek ◽  
Vlasta Justová ◽  
France Catus ◽  
...  

Marek J, Hána V. Kršek M. Justová V, Catus F, Thomas F. Long-term treatment of acromegaly with the slow-release somatostatin analogue lanreotide. Eur J Endocrinol 1994;131:20–6. ISSN 0804–4643 Thirteen patients with active acromegaly despite previous surgery were treated with 30 mg lanreotide im twice a month for 9 months. In 10 subjects the treatment continued to 19 months. GH serum levels of all patients decreased significantly from an initial value of 32.0 (29.4) μg/l [median (standard error of median)] to 10.0 (3.6) and 19.1 (5.7) after 3 and 9 months of treatment, respectively. In the 10 patients with the treatment longer than one year the decrease in GH was from 46.8 (29.4) μg/l to 12.5 (5.0) and 16.1 (5.3) after 13 and 19 months, respectively. IGF-I serum levels decreased significantly from 1193 (73)μg/l to 782 (99) and 621 (103) after 3 and 9 months, respectively, and were normalized in 3 patients. In the 10 patients treated for longer than one year, levels decreased significantly from 1318 (74)μg/l to 653 (170) and 742 (180) after 13 and 19 months, respectively. IGF BP-3 levels were reduced to the normal range in 6 patients and decreased from 8.7 (1.5)mg/l to 6.4 (0.8) and to 5.4 (1.0) after 3 and 9 months, respectively. In the patients with the 19 months treatment the decrease was from 9.3 (1.6) mg/l to 3.9 (0.9) and 4.8 (0.9) after 13 and 19 months, respectively. The IGF BP-3 to IFG I ratio increased in 7 patients. This elevation significantly correlated with the decrease in bioassayable somatomedin. Prolactin serum levels fell in all patients with increased prolactin secretion. Testosterone plasma levels increased in 4 out of 5 men without replacement therapy. Clinical improvement was observed in all patients. A reduction of tumour mass was observed in five patients and complete disappearance of the tumour in one subject. All patients complained of mild abdominal pain and softened stools for several days following the injections. However, these side effects never required interruption of treatment. Asymptomatic microlithiasis was seen in only one patient after 13 months, which led to treatment being suspended for a period of 3 months after which it was resumed. Fasting serum insulin and insulin area under the curve (AUC) after oral glucose tolerance test (OGTT) fell in all patients. Fasting blood glucose, fructosamine and glucose AUC after OGTT slightly increased during the treatment, but all blood glucose levels (fasting and during OGTT) remained within normal ranges. Lanreotide appears to be a safe and effective treatment in patients with active acromegaly unresolved by surgery. The long-acting formulation avoids the drawbacks associated with either repeated daily injections or continuous infusions of somatostatin analogues. Josef Marek, Third Department of Medicine, Charles University, U nemocnice 1, 128 21 Praha 2, The Czech Republic


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