Search for: drug-release
Total 117 records
Characterization and antibacterial performance of electrodeposited chitosan–vancomycin composite coatings for prevention of implant-associated infections [electronic resource], Article Journal of Materials Science and Engineering: C ; 1 August 2014, Volume 41, Pages 240–248 ; Tamjid, E ; Simchi, A. (Abdolreza) ; Sharif University of Technology
Orthopaedic implant-associated infections are one of the most serious complications in orthopaedic surgery and a major cause of implant failure. In the present work, drug-eluting coatings based on chitosan containing various amounts of vancomycin were prepared by a cathodic electrophoretic deposition process on titanium foils. A three-step release mechanism of the antibiotic from the films in a phosphate-buffered saline solution was noticed. At the early stage, physical encapsulation of the drug in the hydrogel network controlled the release rate. At the late stage, however, in vitro degradation/deattachment of chitosan was responsible for the controlled release. Cytotoxicity evaluation of...
Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition, Article International Journal of Hyperthermia ; 2018 ; 02656736 (ISSN) ; Hedayatnasab, Z ; Karimian, H ; Sarraf, M ; Yeong, C. H ; Madaah Hosseini, H. R ; Abu Kasim, N. H ; Wong, T. W ; Rahman, N. A ; Sharif University of Technology
Taylor and Francis Ltd 2018
Purpose: Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy. Materials and methods: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release...
Remote trice light, temperature, and pH-actuation of switchable magneto-plasmonic nanocarriers for combinational photothermal and controlled/targeted chemotherapies, Article Journal of Pharmaceutical Sciences ; Volume 107, Issue 12 , 2018 , Pages 3123-3133 ; 00223549 (ISSN) ; Khoshgenab, A. N ; Amoli Diva, M ; Sadighi Bonabi, R ; Sharif University of Technology
Elsevier B.V 2018
Three magneto-plasmonic nanohybrids were synthesized using Au- and Ag-coated Fe3O4 nanoparticles (NPs)-modified dual pH- and temperature-responsive triblock copolymer of poly (butyl methacrylate-co-acrylamide-co-methacrylic acid) to serve as drug carriers with potential of using in both photothermal and controlled/targeted chemotherapies. The internal superparamagnetic core gives the carriers targeted-delivery characteristics, and surface plasmon resonance–based noble metallic Au/Ag shells give them on-demand photothermal and photo-triggering release properties. To investigate the effect of coating method on the targeting property of synthesized carriers, Au NPs were attached to the magnetic...
Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 26, Issue 2 , 2002 , Pages 197-204 ; 03601307 (ISSN) ; Sharif University of Technology
Potassium chloride, as an osmotic agent and poly methacrylic acid, as a water-swelling additive have been incorporated in polydimethyl siloxane. By using caffeine as a model drug, the results of release experiments from two systems have been compared. Because of osmotic rupturing pseudo-zero-order release kinetics preceded by marked burst effect were observed. Since osmotic pressure of PMAA is higher than that of KCI, drug release rate from PMAA-PDMS matrices is higher than that from KCI-PDMS matrices. Since KCI is release along with the drug, but PMAA is not, therefore water-swelling additives may provide efficient drug release without releasing undesirable substances
The Effect of Protein Corona on Doxorubicin Release from the Magnetic Mesoporous Silica Nanoparticles and the Effect of Polyethylene Glycol Coating on drug Delivery System, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali
The nanoparticles have been widely used in the field of physics, chemistry, electronics and mechanics because of their high surface area. One of their most important applications is in drug delivery systems as smart drug nanocarrier. Magnetic nanoparticles (including Fe2O3, Fe3O4) are the good candidates for this purpose. It is clear that, upon to entrance of nanoparticle into biological media (such as plasma), the surface of nanoparticles were covered by protein layers (protein corona). This layer is very stable and created new surface on the nanoparticles. The protein corona layer intracts with cellular receptors and determines the fate of nanoparticles. Protein corona covers the targeting...
M.Sc. Thesis Sharif University of Technology ; Alemzadeh, Iran
Most natural folate derivatives are highly sensitive to temperature, oxygen and light and their stability depends on food process condition. Alginate and pectin were evaluated for folic acid encapsulation and increasing its stability. By combining them and optimising encapsulation condition the efficiency was enhanced up to 90% . Furthermore, using polymers in combined form caused decrease in folic acid leakage from capsules in acidic condition of stomach. First of all, the time of encapsulation was measured which was 140-180 minutes. In this study the effect of Calcium Chloride concentration on encapsulation was studied. Therefore, two variables were selected which were pectin to algine...
M.Sc. Thesis Sharif University of Technology ; Goodarznia, Iraj
In this study the main goal is to prepare a membrane to perform delayed drug release and absorbtion in the human body. To do so the supercritical method was used. A well-known biodegradable polymer was used. These kinds of polymers are used in drug delivery, wound dressing or scaffolding for cell culture. A membrane produced out of these kin of polymers is expected to have a good accordance with the goals.Ploy Vinyl alcohol, having very good bio degradable characteristics was used as the main polymer and Poly Ethylene Glycol (PEG) was used as an additive to make changes in the membrane structure. Also Dimethyl Sulfoxide, a polar solvent having the capability of solving both polymers is used....
Diffusional release of a dispersed solute from a cylindrical polymeric matrix into an infinite external volume, Article Applied Mathematics and Computation ; Volume 259 , May , 2015 , Pages 676-685 ; 00963003 (ISSN) ; Abdekhodaie, M. J ; Sharif University of Technology
Elsevier Inc 2015
Numerical and analytical exact solutions of diffusional release from a cylindrical polymeric matrix into an infinite medium have been developed in which the initial solute loading (A) is greater than solubility limit (Cs). Also, the effects of boundary layers on the drug release rate have been studied. The numerical solution is valid for any initial drug loading whereas analytical solution can be used for high values of drug loading. Comparisons have been made between numerical and analytical exact solutions in upper and lower bounds (A/Cs蠑1 and A/Cs→1) and previously presented approximate solution. The presented results validate the proposed numerical solution
Article Materials Science and Engineering C ; Volume 76 , 2017 , Pages 536-542 ; 09284931 (ISSN) ; Sadighi Bonabi, R ; Pourghazi, K ; Sharif University of Technology
Elsevier Ltd 2017
Laser assisted drug release from a synthesized plain polymer composed of poly (butyl methacrylate-co-acrylamide-co-methacrylic acid) [P(BMA-co-AAm-co-MAA)] and a metallo-polymer composed of silver nanoparticles (Ag NPs) grafted plain polymer (the nanocomposite) were studied to investigate their capability to serve as drug carriers. Positive temperature dependent swelling changes were observed for both carriers and their thermal sensitivity and thermal and optical switching properties were investigated in two buffered solutions. An acidic solution with pH = 1.2 to simulate stomach body condition and a neutral solution with pH = 7.4 to simulate intestine condition. Reversible phase transition...
Fabrication and Characterization of a Drug Release System Based on Mesoporous Silica Nanoparticles for Hydrophobic Drugs
Sharif University of Technology
This research aims to develop a drug delivery system based on mesoporous silica nanoparticles (MSNPs) for hydrophobic drugs and evaluating their cytotoxicity. The internal environment of the body is aqueous, while most of effective drugs display poor aqueous solubility, resulting in insufficient bioavailability. Due to their several unique properties, such as a large surface area, tunable pore size, facile surface multi functionalization and excellent biocompatibility, MSNPs are recognized as promising and powerful tools to overcome this hurdle. In the present study, MSNPs were synthesized using template removing method and then were functionalized through grafting procedure. They were...
Evaluation of Controlled Drug Release Chitosan-based Coatings on Titanium Implants: Microstructure, Bioactivity and Biocompatibility, Ph.D. Dissertation Sharif University of Technology ; Simchi, Abdolreza
Implant-associated infections are one of the most serious complications in orthopaedic and trauma surgery as it may result in poor functional outcome, implant failure, chronic osteomyelitis or even death. Great concerns have been taken to reduce implant-associated infections through progressing in operating standards, minimizing the possibility of contamination during surgery, reducing the establishment of infection by perioperative antibiotic prophylaxis, and confining of pathogenic strains by patient isolation. In spite of these preventions, the percentage of postoperative infections is still rising. Composite coatings with bone-bioactivity and drug-eluting capacity are considered as...
The Study on Relationship between Viscoelastic Properties and Drug Release of Wound Dress Polyvinyl Alcohol Hydrogel, M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza ; Pircheraghi, Gholamreza
Wound is a defect or failure in the skin texture which occurs as a result of physical or heat injuries or physiological conditions. The wound dress as a temporary cover can improve wound healing process and due to the unique properties, hydrogels have become appropriate choice for this application. Hydrogel’s structure allows drug to be loaded in the wound dress. Hydrogel wound dress should have adequate fluidity to cover wound’s bed and make full contact with the skin. Sufficient cohesion and strength is also necessary to allow the wound dress to remove from wound completely. Therefore, the study on the viscoelastic properties of hydrogel is important. In this study, polyvinyl alcohol...
M.Sc. Thesis Sharif University of Technology ; Nemati, Ali ; Dobakhti, Faramarz
In this project, Fe3O4 nanoparticles were synthesized and coated with different polymeric materials for drug delivery application. For this purpose, water dispersible oleic acid(OA)- pluronic block copolymer coated magnetite iron oxide nanoparticles were synthesized that can be loaded with proper doses of cephalexin. Our data indicated that formulation of iron oxide nanoparticles was developed by optimizing the amount of oleic acid required to coat iron oxide nanoparticles and then by optimizing the amount of pluronic required to form an aqueous dispersion of oleic acid coated nanoparticles. Synthesis of magnetite nanoparticles was done by the addition of a strong base (NH4OH) to ferrous...
Investigating the Effect of Geometric Shape and Properties of Protein Corona on Drug Release Using Finite Element Method, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza
In novel drug delivery systems, once nanocarriers confront the biological milieu, their surface is rapidly covered with a layer of biomolecules (i.e., “protein corona”) which play an important role in their drug release rate. Various experimental studies have been done to elucidate the effect of nanoparticles properties on the drug release rate in different biological applications. The physical and geometrical properties of protein corona totally influence on the release profile. In this study, we proposed a suitable finite element model which contains the nanoparticles and the protein layer with their properties in the biological milieu. To this end, diffusion parameters including diffusion...
M.Sc. Thesis Sharif University of Technology ; Shamloo, Amir ; Asghari, Mohsen
Polymeric microspheres which can load biomolecules, proteins and growth factors play an important role in tissue engineering and drug delivery systems. The size of the microspheres and encapsulation efficiency exert a considerable impact on the usability of them. In this study double emulsion method is used for fabrication of microspheres. Effect of different parameters namely the speed of homogenization, time of homogenization, the amount of polymer in oil phase, the surfactant concentration in different phases on the size and surface morphology of the microspheres are investigated. Moreover, a release test for BSA loaded microspheres is conducted. Results indicate that by increasing the...
M.Sc. Thesis Sharif University of Technology ; Frounchi, Masood
Successful treatment of bone infections is a major orthopedic challenge due to the physiological and anatomical features of bone. In this project, we prepared a drug delivery system with injectable and biodegradable polysaccharide agar containing alginate, polyvinyl alcohol and hydroxyapatite nanocarriers composite microspheres. Alginate and polyvinyl alcohol composite microspheres are crosslinked by calcium and freeze-thawing technique. Using the freeze thawing process for polyvinyl alcohol crosslinking, in addition to alginate crosslinking, improved hydrogel swelling behavior and enhanced drug loading and thus slowed drug release, drug loading increased with increasing PVA percentage from ...
Design and physicochemical characterization of lysozyme loaded niosomal formulations as a new controlled delivery system, Article Pharmaceutical Chemistry Journal ; Volume 53, Issue 10 , 2020 , Pages 921-930 ; Ehsani, P ; Cohan, R. A ; Sardari, S ; Akbarzadeh, I ; Bakhshandeh, H ; Norouzian, D ; Sharif University of Technology
Lysozyme loaded niosomes containing various molar ratios of two kinds of surfactants were prepared and the properties of these niosomal formulations were studied. The results revealed that the size of niosomes varied between 240.06 ± 32.41 and 895.2 ± 20.84 nm. Formulations with the lowest size and no precipitation had entrapment efficiencies ranging from 60.644 ± 3.310 to 66.333 ± 1.98%. Their controlled release profiles after 48 h were 15.67, 20.67 and 31.50%. After 2 months, the most stable formulation in terms of size, PDI, zeta potential, and entrapment efficiency was used to study the secondary structures of lysozyme in niosomal and free forms. Lysozyme loaded niosome and lysozyme...
Switchable on/off drug release from gold nanoparticles-grafted dual light- and temperature-responsive hydrogel for controlled drug delivery, Article Materials Science and Engineering C ; Volume 76 , 2017 , Pages 242-248 ; 09284931 (ISSN) ; Sadighi Bonabi, R ; Pourghazi, K ; Sharif University of Technology
Elsevier Ltd 2017
A switchable dual light- and temperature-responsive drug carrier using gold nanoparticles (Au NPs)-grafted poly(dimethylacrylamide-co-acrylamide)/poly acrylic acid [P(DMA-co-AAm)/PAAc] hydrogel was prepared by free radical polymerization procedure using N,N-methylenebisacrylamide as cross-linker and ammonium persulfate as initiator. Initial P(DMA-co-AAm) hydrogel and uniformly-distributed stable Au NPs, prepared by reduction of hydrogen tetrachloroaureate (III) hydrate in the presence of trisodium citrate, were synthesized separately. Then, the prepared P(DMA-co-AAm) and Au NPs were added to an acrylic acid solution along with the cross-linker and initiator to prepare PAAc hydrogel within...
Article Acta Biomaterialia ; Volume 77 , 2018 , Pages 38-47 ; 17427061 (ISSN) ; Goodarzi Hosseinabadi, H ; Cecen, B ; Hassan, S ; Shrike Zhang, Y ; Sharif University of Technology
We report the development of an efficient, customized spherical indentation-based testing method to systematically estimate the hydraulic permeability of gelatin methacryloyl (GelMA) hydrogels fabricated in a wide range of mass concentrations and photocrosslinking conditions. Numerical simulations and Biot's theory of poroelasticity were implemented to calibrate our experimental data. We correlated elastic moduli and permeability coefficients with different GelMA concentrations and crosslinking densities. Our model could also predict drug release rates from the GelMA hydrogels and diffusion of biomolecules into the three-dimensional GelMA hydrogels. The results potentially provide a design...
Article Acta Biomaterialia ; Volume 92 , 2019 , Pages 1-18 ; 17427061 (ISSN) ; Rabiee, N ; Bagherzadeh, M ; Ahmadi, S ; Rabiee, M ; Roghani Mamaqani, H ; Tahriri, M ; Tayebi, L ; Hamblin, M. R ; Sharif University of Technology
Acta Materialia Inc 2019
Nanogels are three-dimensional nanoscale networks formed by physically or chemically cross-linking polymers. Nanogels have been explored as drug delivery systems due to their advantageous properties, such as biocompatibility, high stability, tunable particle size, drug loading capacity, and possible modification of the surface for active targeting by attaching ligands that recognize cognate receptors on the target cells or tissues. Nanogels can be designed to be stimulus responsive, and react to internal or external stimuli such as pH, temperature, light and redox, thus resulting in the controlled release of loaded drugs. This “smart” targeting ability prevents drug accumulation in...