TEMPO-Oxidized Cellulose Beads as Potential pH-Responsive Carriers for Site-Specific Drug Delivery in the Gastrointestinal Tract

The development of controlled drug delivery systems based on bio-renewable materials is an emerging strategy. In this work, a controlled drug delivery system based on mesoporous oxidized cellulose beads (OCBs) was successfully developed by a facile and green method. The introduction of the carboxyl groups mediated by the TEMPO(2,2,6,6-tetramethylpiperidine-1-oxyradical)/NaClO/NaClO2 system presents the pH-responsive ability to cellulose beads, which can retain the drug in beads at pH = 1.2 and release at pH = 7.0. The release rate can be controlled by simply adjusting the degree of oxidation to achieve drug release at different locations and periods. A higher degree of oxidation corresponds to a faster release rate, which is attributed to a higher degree of re-swelling and higher hydrophilicity of OCBs. The zero-order release kinetics of the model drugs from the OCBs suggested a constant drug release rate, which is conducive to maintaining blood drug concentration, reducing side effects and administration frequency. At the same time, the effects of different model drugs and different drug-loading solvents on the release behavior and the physical state of the drugs loaded in the beads were studied. In summary, the pH-responsive oxidized cellulose beads with good biocompatibility, low cost, and adjustable release rate have shown great potential in the field of controlled drug release.

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pH-Responsive polymeric Janus containers for controlled drug delivery

Polymer Chemistry ◽

10.1039/c5py00267b ◽

2015 ◽

Vol 6 (22) ◽

pp. 4144-4153 ◽

Cited By ~ 17

Author(s):

Ziguang Zhao ◽

Feiyan Zhu ◽

Xiaozhong Qu ◽

Qiuhua Wu ◽

Qian Wang ◽

...

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Hollow Spheres ◽

Controlled Drug Delivery ◽

Controlled Drug Release ◽

Ph Responsive

In this study, we have successfully designed and fabricated pH-responsive polymeric Janus hollow spheres for controlled drug release.

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pH and Redox Dual-Responsive MSN-S-S-CS as a Drug Delivery System in Cancer Therapy

Materials ◽

10.3390/ma13061279 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1279 ◽

Cited By ~ 2

Author(s):

Yanqin Xu ◽

Liyue Xiao ◽

Yating Chang ◽

Yuan Cao ◽

Changguo Chen ◽

...

Keyword(s):

Drug Delivery ◽

Cancer Therapy ◽

Drug Release ◽

Drug Delivery System ◽

Delivery System ◽

Release Rate ◽

Drug Loading ◽

Impregnation Method ◽

Amino Groups ◽

Dual Responsive

In order to achieve a controlled release drug delivery system (DDS) for cancer therapy, a pH and redox dual-responsive mesoporous silica nanoparticles (MSN)-sulfur (S)-S- chitosan (CS) DDS was prepared via an amide reaction of dithiodipropionic acid with amino groups on the surface of MSN and amino groups on the surface of CS. Using salicylic acid (SA) as a model drug, SA@MSN-S-S-CS was prepared by an impregnation method. Subsequently, the stability, swelling properties and drug release properties of the DDS were studied by x-ray diffraction, scanning electron microscopy, Fourier transform infrared microspectroscopy, size and zeta potential as well as Brunauer–Emmett–Teller surface area. Pore size and volume of the composites decreased after drug loading but maintained a stable structure. The calculated drug loading rate and encapsulation efficiency were 8.17% and 55.64%, respectively. The in vitro drug release rate was 21.54% in response to glutathione, and the release rate showed a marked increase as the pH decreased. Overall, double response functions of MSN-S-S-CS had unique advantages in controlled drug delivery, and may be a new clinical application of DDS in cancer therapy.

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Combine Drug Delivery of Thymoquinone-Doxorubicin by Cockle Shellderived pH-sensitive Aragonite CaCO3 Nanoparticles

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681209666190508122540 ◽

2020 ◽

Vol 10 (4) ◽

pp. 518-533 ◽

Cited By ~ 2

Author(s):

Kehinde M. Ibiyeye ◽

Abu B.Z. Zuki ◽

Norshariza Nurdin ◽

Mokrish Ajat

Keyword(s):

Electron Microscopy ◽

Drug Delivery ◽

Calcium Carbonate ◽

Drug Release ◽

Release Kinetics ◽

Drug Loading ◽

Ph Sensitive ◽

Multiple Drug ◽

Burst Release ◽

Cockle Shell

Background: Cockleshell-derived aragonite calcium carbonate nanoparticles were prepared by the top-down approach for combine delivery of two types of drugs. Objective: The aim of this study was to synthesize and characterize thymoquinone-doxorubicin loaded cockle shell-derived aragonite calcium carbonate nanoparticle. Aragonite calcium carbonate nanoparticles encapsulating thymoquinone and doxorubicin alone were also prepared. Methods: The blank and drug-loaded nanoparticles were characterized by field emission scanning electron microscopy, transmission electron microscopy, Zeta potential, Fourier transformed infrared and X-ray diffraction. Drug delivery properties, in vitro drug release study at pH 7.4, 6 and 4.8, and effect of blank nanoparticles on MCF10A, 3T3, MDA MB231 cells were also analyzed. Results: The blank and drug-loaded nanoparticles were pleomorphic and their sizes varying from 53.65 ± 10.29 nm to 60.49 ± 11.36 nm with an overall negative charge. The entrapment efficiency of thymoquinone and doxorubicin were 41.6 and 95.8, respectively. The FTIR showed little alteration after loading thymoquinone and doxorubicin while XRD patterns revealed no changes in the crystallizations of nanoparticles after drug loading. The drug release kinetics of doxorubicin and thymoquinone from the nanoparticles showed a continuous and gradual release after an initial burst release was observed. At pH 4.8, about 100% of drug release was noticed, 70% at pH 6 while only 50% at pH 7.4. The cell viability was 80% at a concentration of 1000 ug/ml of blank nanoparticle. Conclusion: The cockle shell-derived pH sensitive aragonite calcium carbonate nanoparticle provides an effective and simple means of multiple drug delivery and function as a platform for pH controlled release of loaded therapeutic agents.

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Exploring dendrimer towards dual drug delivery: pH responsive simultaneous drug-release kinetics

Journal of Microencapsulation ◽

10.1080/02652040802312572 ◽

2009 ◽

Vol 26 (4) ◽

pp. 287-296 ◽

Cited By ~ 104

Author(s):

Rakesh Kumar Tekade ◽

Tathagata Dutta ◽

Virendra Gajbhiye ◽

Narendra Kumar Jain

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Release Kinetics ◽

Ph Responsive ◽

Drug Release Kinetics ◽

Dual Drug

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PLGA Nanoparticles for Anti Tuberculosis Drug Delivery

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.584.465 ◽

2012 ◽

Vol 584 ◽

pp. 465-469 ◽

Cited By ~ 2

Author(s):

S. Malathi ◽

S. Balasubramanian

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Release Kinetics ◽

Drug Loading ◽

Double Emulsion ◽

Plga Nanoparticles ◽

Release Mechanism ◽

Sustained Drug Release ◽

Drug Release Kinetics ◽

Evaporation Technique

Nanoparticles-based drug delivery systems have considerable potential for the treatment of tuberculosis (TB). A series of PLGA polymers with different molar feed ratios (P2:87/13, P3:83/17, P5:63/37, P6:76/24, P9:53/47) were synthesized by direct melt poly condensation method. The resulting biodegradable polymers were characterized by FTIR and 1H NMR spectroscopy. The preparation of the drug (Pyrazinamide (PZA)) encapsulated PLGA polymers were carried out by double emulsion – solvent evaporation technique. The drug loaded PLGA-NPs were analyzed by UV-visible spectroscopy and scanning electron microscopy. The drug loading efficiency and drug release kinetics varies in the following order: P9>P5>P6>P3>P2. Among the formulations, PP9 showed a uniform as well as sustained drug release. The drug release kinetics has been evaluated by Zero-order, First order, Higuchi and Koresmeyer- Peppas models and the release mechanism has also been investigated

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Biocompatible thermo-responsive N-vinylcaprolactam based hydrogels for controlled drug delivery systems

Bionatura ◽

10.21931/rb/2021.06.02.8 ◽

2021 ◽

Vol 6 (2) ◽

pp. 1712-1719

Author(s):

J. Fernanda Romero ◽

Antonio Díaz-Barrios ◽

Gema González

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Drug Delivery Systems ◽

Drug Loading ◽

Particle Diameter ◽

Controlled Drug Delivery ◽

Delivery Systems ◽

The Body ◽

Glycol Diacrylate ◽

Vis Spectroscopy

The treatment of several diseases requires drugs commonly administered orally or intravenously. Said administration has several drawbacks, such as low control of the necessary drug levels in plasma, making the treatment ineffective and, furthermore, side effects and low compatibility with the patient. Recently, the use of stimuli-responsive hydrogels in controlled Drug Delivery Systems (DDSs) has been considered an excellent alternative because of its inherent biocompatibility, responsiveness to physiological changes in the body, and diversity of both natural and synthetic material options. The present work focuses mainly on the synthesis, characterization, and drug release capacity of poly (N-vinyl caprolactam) (PVCL) and poly (N-vinyl caprolactam) microgels crosslinked with various concentrations of poly (ethylene glycol) diacrylate (PEGDA), which show temperature stimuli-responsiveness near the physiological temperature of the human body. For that reason, changes in the average hydrodynamic particle diameter at different temperatures are estimated and correlated with the drug release rate. The model drug chosen for releasing studies is colchicine, a potential drug for gout disease treatment, currently in disuse because of its low therapeutic index. It is expected that the use of the control release procedure by drug encapsulation in this polymer overcomes this drawback. The synthesis of PVCL homopolymer and three VCL-co-PEGDA hydrogels varying the PEGDA crosslinker concentration was successfully carried out by emulsion polymerization. Their characterization was performed by DLS and FTIR spectroscopy. Polymerization yields were estimated by total solids analysis, and UV-VIS determined the cloud points. Finally, the drug loading and release over time were monitored by HPLC and UV-VIS spectroscopy showing that drug release profiles obtained corresponded to a sustained drug delivery system.

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Towards Heterogeneous Biodegradable Nanorods for Controlled Drug Delivery

MRS Proceedings ◽

10.1557/proc-1138-ff02-08 ◽

2008 ◽

Vol 1138 ◽

Author(s):

Shelley Dougherty ◽

Jianyu Liang

Keyword(s):

Thin Films ◽

Drug Delivery ◽

Drug Release ◽

Biomedical Applications ◽

Release Kinetics ◽

Controlled Drug Delivery ◽

Unique Combination ◽

Multiple Functions ◽

One Dimensional ◽

Heterogeneous Polymer

AbstractHeterogeneous, one-dimensional (1D) nanomaterials, such as nanorods and nanowires, have been utilized for a variety of different biomedical applications because they offer a unique combination of properties and provide a material platform for integrating multiple functions. In this paper, we propose a template-assisted wetting approach to fabricate segmented polymer nanorods using biodegradable polymers for controlled drug delivery. Our previous work with polystyrene (PS) and poly(methyl methacrylate) (PMMA) heterogeneous, segmented nanorods is described briefly to introduce our current preliminary work with the fabrication of homogeneous biodegradable nanorods and drug release from polymer thin films. Since the template-assisted fabrication approach provides us unprecedented control over the size, spacing, and length of the heterogeneous polymer nanorods, this technique will provide for the opportunity to evaluate drug release kinetics as a function of the segment spacing, size of the nanorods, and aspect ratio in the future.

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In Vitro Evaluation of a Peptide-Mesoporous Silica Nanoparticle Drug Release System against HIV-1

Inorganics ◽

10.3390/inorganics8070042 ◽

2020 ◽

Vol 8 (7) ◽

pp. 42 ◽

Cited By ~ 1

Author(s):

Katharina Braun ◽

Christina M. Stürzel ◽

Frank Kirchhoff ◽

Mika Lindén

Keyword(s):

Drug Release ◽

Mesoporous Silica ◽

Release Rate ◽

Serum Proteins ◽

Release Kinetics ◽

Drug Loading ◽

Active Form ◽

Equilibrium Concentration ◽

Hiv 1

It has been shown that the optimized VIR-576 derivative of the natural HIV-1 entry inhibitor targeting the viral gp41 fusion peptide is safe and effective in infected individuals. However, high doses of this peptide were required, and stability, as well as delivery, must be improved for clinical application. Here, we examined the loading and release of VIR-576 into/from mesoporous silica nanoparticles (MSNs) in vitro. We found that a moderately high peptide loading of 11.5 wt % could be achieved by adsorption from PBS buffer (pH 7.2), i.e., under mild, fully peptide-compatible conditions. The release rate of peptide into the same buffer was slow and the equilibrium concentration as indicated by the adsorption isotherm could not be reached even within 50 h at the particle concentrations studied. However, a faster release was observed at lower particle concentrations, indicating that partial particle dissolution had a positive influence on peptide release. To determine the antiviral activity of VIR-576-loaded MSNs, TZM-bl indicator cells were exposed to HIV-1 and the infection rates were followed as a function of time and VIR-576 concentration. The inhibitory activity observed for VIR-576 released from the MSNs was virtually identical to that of free VIR-576 at the 48 h time point, indicating that (a) VIR-576 was released in an active form from the MSNs, and (b) the release rate in the presence of serum proteins was clearly higher than that observed under protein-free conditions. These observations are discussed based on competitive peptide/protein adsorption, as well as potential influences of serum proteins on the dissolution-reprecipitation of silica under conditions where the total silica concentration is above the saturation level for dissolved silica. Our results highlight the need for studying drug release kinetics in the presence of serum proteins, in order to allow for a better extrapolation of in vitro data to in vivo conditions. Furthermore, due to the high peptide loadings that can be achieved using MSNs as carriers, such a formulation appears promising for local release applications. For systemic administration, however, peptides with a higher potency would be needed, due to their high molar masses limiting the drug loading in terms of moles per gram carrier.

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Formulation and In vitro Evaluation of Eudragit RL 100 Loaded Fexofenadine HCl Microspheres

Bangladesh Pharmaceutical Journal ◽

10.3329/bpj.v19i1.29240 ◽

2016 ◽

Vol 19 (1) ◽

pp. 58-67

Author(s):

Paroma Arefin ◽

Ikramul Hasan ◽

Md Shfiqul Islam ◽

Md Selim Reza

Keyword(s):

Drug Release ◽

Release Rate ◽

Encapsulation Efficiency ◽

Release Kinetics ◽

Drug Loading ◽

Release Mechanism ◽

Order Release ◽

Eudragit Rl ◽

Fexofenadine Hcl

The present study deals with the formulation and evaluation of Fexofenadine hydrochloride (HCl) loaded sustained release microspheres by emulsion solvent evaporation method with Eudragit RL 100. The effects of percent drug loading on drug encapsulation efficiency, drug content and drug release rate were assessed. In vitro dissolution study was performed spectrophotometrically according to USP paddle method using phosphate buffer (pH 6.8) for 10 hours. The release rate of Fexofenadine HCl from the microspheres was significantly increased with the increase of drug loading. The drug release patterns were simulated in different kinetic orders such as zero order release kinetics, first order release kinetics, Higuchi release kinetics, Korsmeyer-Peppas release kinetics and Hixson-Crowell release kinetics to assess the release mechanism and Higuchi release kinetics was found to be the predominant release mechanism. Morphological changes due to different drug loading were assessed by scanning electron microscopic (SEM) technique. Differential scanning calorimetry and fourier transform infra-red (FT-IR) spectroscopy was performed to evaluate compatibility of drug with the polymer. A statistically significant variation indrug encapsulation efficiency and release rate was observed for variation in drug loading.Bangladesh Pharmaceutical Journal 19(1): 58-67, 2016

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Dual stimuli-responsive polyphosphazene-based molecular gates for controlled drug delivery in lung cancer cells

RSC Advances ◽

10.1039/d0ra03210g ◽

2020 ◽

Vol 10 (46) ◽

pp. 27305-27314

Author(s):

Yolanda Salinas ◽

Michael Kneidinger ◽

Cristina Fornaguera ◽

Salvador Borrós ◽

Oliver Brüggemann ◽

...

Keyword(s):

Lung Cancer ◽

Drug Delivery ◽

Drug Release ◽

Mesoporous Silica Nanoparticles ◽

Controlled Drug Delivery ◽

Controlled Drug Release ◽

Stimuli Responsive ◽

Ph Responsive ◽

Bottle Brush ◽

Molecular Gates

Bottle-brush polyphosphazenes as dual, thermosensitive and pH responsive gatekeepers for mesoporous silica nanoparticles, and their use in controlled drug release.

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