Preparation and Drug Release Behavior from a Temperature-Sensitive Poly(aspartic Acid) Derivatives Hydrogel

2013 ◽  
Vol 711 ◽  
pp. 18-21
Author(s):  
Kui Lin Deng ◽  
Chun Xiu Li ◽  
Ting Gao ◽  
Xiao Dan Fu ◽  
Wen Hui Jin ◽  
...  

In this paper, a new pH/temperature-sensitive beads with semi-interpenetrating polymeric network based on sodium alginate(SA) and poly(aspartic acid) derivatives(M-E-PSI) were prepared using as drug delivery carrier. With indomethacin as a drug model,we investigated the release behaviors of indomethacin in different pH value, temperature and ratio of SA/ M-E-PSI. It turned out that the release amount of indomethacin in pH=2.1 phosphate buffer solution(PBS) was evidently higher than that in pH=7.4 PBS. And also, the release amount of indomethacin was also increased with increasing temperature and poly(aspartic acid) derivatives content in the beads.

2010 ◽  
Vol 148-149 ◽  
pp. 1427-1430 ◽  
Author(s):  
Kui Lin Deng ◽  
Li Rong Dong ◽  
Yu E Shi ◽  
Yu Bo Gou ◽  
Qian Li ◽  
...  

As a drug delivery carrier, a novel pH/temperature sensitive bead (pTSB) with core-shelled structure from poly(N-acryloylglycine) (PAG), copoly(N-acryloylglycine methyl este and N-acryloylglycine ethyl ester) was prepared by two steps. In pH=7.4 phosphate buffer solution (PBS), the cumulative release amount of indomethacin loaded in the pTSB was about 60.1 % within 500 mins, but this value only reached to 22.3 % in pH=2.1 PBS. The release behaviors of indomethacin from pTSB also exhibited a remarkable dependence on PAG content in the core. Additionally, the release rate of indomethacin was much faster at 18 oC than that at 37 oC due to the temperature sensitivity of poly(N-acryloylglycinates). The experimental results indicate that pTSB seems to have a potential application in the drug release system controlled via pH or temperature in the biomedical fields.


2010 ◽  
Vol 148-149 ◽  
pp. 1449-1452 ◽  
Author(s):  
Kui Lin Deng ◽  
Yu Bo Gou ◽  
Jian Zuo ◽  
Li Rong Dong ◽  
Qian Li ◽  
...  

A series of pH/temperature sensitive hydrogel beads with semi-interpenetrating polymer network (semi-IPN), composed of sodium alginate and poly(N-acryloylglycinate) were prepared as drug delivery carrier. In pH=2.3 phosphate buffer solution (PBS), the release amount of indomethacin incorporated into the beads was about 9% within 610 min, while this value approached to 68% in pH=7.4 PBS. The release rate of indomethacin was higher at 37 than that at 20 . In addition, the release amount of indomethacin was increased with increasing poly(N-acryloylglycinate) content. These results suggest that the stimuli-sensitive beads have the potential to be used as an effective pH/temperature delivery system in bio-medical fields.


2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Shafiyah Pondi ◽  
Jon Efendi ◽  
Ho Chin Siong ◽  
Lai Sin Yuan ◽  
Sheela Chandren ◽  
...  

The drug-delivery field has been an attractive as well as challenging area for research. With the emerging of new formulated drugs and pharmaceutical compounds, development of good drug-delivery system (DDS) is crucially required. This study aims to utilize albumin as the drug template in silica/albumin/drug (S/A/D) system. Prior to designing this system, the interaction between silica and albumin was investigated. It is hypothesized that high interaction between silica and albumin may result in slower drug release over time, which is preferred for a good DDS. Silica and albumin (S/A) materials were prepared by using fumed silica and tetraethyl orthosilicate (TEOS) as the silica precursors. Three different S/A samples were prepared; fumed silica with albumin (FS/A), fumed silica with pre-treated albumin by sodium borohydrate (FS/A-N), and silica sol (TEOS) with albumin (SS/A). In-vitro release of albumin in phosphate buffer solution (pH 7) was carried out to examine the interaction between albumin and silica. The concentration of albumin was detected at 280 nm by UV-visible spectrophotometer. All samples were characterized by diffuse reflectance-UV-visible spectrophotometer (DR-UV), Fourier transform infrared spectrophotometer (FTIR) dan thermogravimetric-differential thermal analysis (TG-DTA). DR-UV results show that SS/A exhibited the lowest absorption intensity at 280 nm, which indicates better interaction between silica and albumin. This result was supported by the presence of Si-O stretching band of silanol at 952 cm-1 from the FTIR spectrum. Release study of albumin demonstrated that the release of albumin from SS/A was slowest compared to those of FS/A and FS/A-N. 


2018 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Jessica Oliveira ◽  
Raquel Rodrigues ◽  
Lillian Barros ◽  
Isabel Ferreira ◽  
Luís Marchesi ◽  
...  

In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were coated with carbon-based shell for drug delivery application. The nanocomposites were further chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity 18% higher in mimicking tumor environment than in the physiological one. Therefore, this study demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used in the future for the treatment of cancer "in situ" by means of controlled drug release.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 487 ◽  
Author(s):  
Preem ◽  
Bock ◽  
Hinnu ◽  
Putrinš ◽  
Sagor ◽  
...  

New strategies are continuously sought for the treatment of skin and wound infections due to increased problems with non-healing wounds. Electrospun nanofiber mats with antibacterial agents as drug delivery systems provide opportunities for the eradication of bacterial infections as well as wound healing. Antibacterial activities of such mats are directly linked with their drug release behavior. Traditional pharmacopoeial drug release testing settings are not always suitable for analyzing the release behavior of fiber mats intended for the local drug delivery. We tested and compared different drug release model systems for the previously characterized electrospun chloramphenicol (CAM)-loaded nanofiber (polycaprolactone (PCL)) and microfiber (PCL in combination with polyethylene oxide) mats with different drug release profiles. Drug release into buffer solution and hydrogel was investigated and drug concentration was determined using either high-performance liquid chromatography, ultraviolet-visible spectrophotometry, or ultraviolet (UV) imaging. The CAM release and its antibacterial effects in disc diffusion assay were assessed by bacterial bioreporters. All tested model systems enabled to study the drug release from electrospun mats. It was found that the release into buffer solution showed larger differences in the drug release rate between differently designed mats compared to the hydrogel release tests. The UV imaging method provided an insight into the interactions with an agarose hydrogel mimicking wound tissue, thus giving us information about early drug release from the mat. Bacterial bioreporters showed clear correlations between the drug release into gel and antibacterial activity of the electrospun CAM-loaded mats.


MedChemComm ◽  
2015 ◽  
Vol 6 (10) ◽  
pp. 1874-1881 ◽  
Author(s):  
Yongyong Li ◽  
Yuqin Chen ◽  
Haiqing Dong ◽  
Chunyan Dong

Supramolecular, prodrug-based micelles (SMPMs) with enzyme-induced drug release behavior were engineeredviahost–guest interaction of camptothecin carrying PCL and α-cyclodextrin.


2020 ◽  
Vol 16 (3) ◽  
pp. 308-315
Author(s):  
Xiaoyan Li ◽  
Hui Xie ◽  
Guiling Luo ◽  
Yanyan Niu ◽  
Xiaobao Li ◽  
...  

Background: Graphene quantum dots (GQD) is a new member of carbon nanomaterial that has attracted increasing attention owing to its better chemical inertness, low cytotoxicity, large specific surface area, cheap cost, suitable conductivity and excellent biocompatibility. Methods: Electrochemical behaviors of this modified electrode were studied by cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical investigations of Nafion/Hb/GQD/ CILE were carried out with electrochemical parameters calculated. Results: In the phosphate buffer solution with a pH value of 5.0, good linear relationships between the catalytic reduction current and the concentration of substrate were got for TCA (6.0~100.0 mmol·L-1), NaNO2 (2.0~12.0 mmol·L-1) and H2O2 (6.0~30.0 mmol·L-1). The proposed method was applied to NaNO2 concentration detection in soak water from picked vegetables with satisfactory results. Conclusion: This Nafion/Hb/GQD/CILE had a good bioelectrocatalytic activity to different substrates such as trichloroacetic acid, NaNO2 and H2O2 reduction with the advantages including wide detection range, low detection limit and good stability. Therefore, the application of GQD in electrochemical sensor was extended in this paper.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1974
Author(s):  
Juan Carlos Quintanilla de Stéfano ◽  
Vanessa Abundis-Correa ◽  
Sergio Daniel Herrera-Flores ◽  
Alejandro J. Alvarez

The drug release behavior of pH-sensitive starch-based hydrogels was systematically studied. Hydrogels were synthesized by copolymerization of acrylic acid (AA) and other acrylate comonomers onto the starch backbone. The hydrophilic agents 2-hydroxy ethyl methacrylate (HEMA), and acrylamide (AAm), as well as the hydrophobic butyl-methacrylate (BMA), were utilized as comonomers. Methylene-bisacrylamide (MBA) was employed as a crosslinking agent. The synthesized hydrogels were loaded with caffeine as a model drug. The effects of the hydrophobic/hydrophilic character of the comonomers and chemical crosslinking on the swelling capacity and the release rate of caffeine were investigated. The use of the crosslinking agent and hydrophobic monomers decreased the swelling capacity of the hydrogels. The release rate of caffeine increased with the presence of a hydrophobic monomer. The fastest release was obtained with the AA/BMA/AAm formulation, and the slowest release was observed with the AA/HEMA/AAm formulation. The transport mechanism was controlled by Fickian diffusion in formulations containing AAm, and controlled by the polymer-relaxation mechanism in formulations containing MBA. Overall, our results showed that the swelling and drug delivery behavior can be tuned by varying the chemical composition of the copolymer formulations. These starch-based hydrogels can be useful as drug delivery devices in many biomedical applications.


2004 ◽  
Vol 828 ◽  
Author(s):  
Prashant K. Jha ◽  
P. I. Gouma

ABSTRACTMolybdenum trioxide sol-gel matrices were tested for their ability to host biomaterials in their structures without adversely affecting the activity of the encapsulated biomolecules. The sol-gel composites were prepared at room temperature; the urease was added during the hydrolysis step to ensure proper encapsulation in the pore structure of the sol. Phosphate buffer solution was added during this stage to maintain the pH value of the sol in the bio-compatible range. The activity of incorporated urease was tested by exposing composite sol-gel material to standard urea test solutions and measuring the amount of gaseous ammonia (released by the reaction of urea with water in the presence of urease) using an ammonia electrode. The concentration of urea solutions ranged from 1mM to 10mM. An electronic olfactory system (EOS 835) was also employed to detect the presence of gaseous ammonia. Gas sensing tests were done to verify the sensitivity of the matrix to ammonia. Microstructural analysis was carried out by means of scanning and transmission electron microscopy. It was found that urease retained its activity inside molybdenum trioxide sol-gels that are sensitive to ammonia. These hybrid nanoporous composites are useful in the field of biosensors and fuel cells.


Sign in / Sign up

Export Citation Format

Share Document