scholarly journals Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

2019 ◽  
Vol 10 ◽  
pp. 2579-2593 ◽  
Author(s):  
Dávid Juriga ◽  
Evelin Sipos ◽  
Orsolya Hegedűs ◽  
Gábor Varga ◽  
Miklós Zrínyi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Amino Acid ◽  
Drug Release ◽  
Disulfide Bonds ◽  
Release Kinetics ◽  
Building Blocks ◽  
Periodontal Ligament Cells ◽  
Polymer Backbone ◽  
Model Drug

Polymer hydrogels are ideal scaffolds for both tissue engineering and drug delivery. A great advantage of poly(amino acid)-based hydrogels is their high similarity to natural proteins. However, their expensive and complicated synthesis often limits their application. The use of poly(aspartic acid) (PASP) seems an appropriate solution for this problem due to the relatively cheap and simple synthesis of PASP. Using amino acids not only as building blocks in the polymer backbone but also as cross-linkers can improve the biocompatibility and the biodegradability of the hydrogel. In this paper, PASP cross-linked with cystamine (CYS) and lysine-methylester (LYS) was introduced as fully amino acid-based polymer hydrogel. Gels were synthesized employing six different ratios of CYS and LYS. The pH dependent swelling degree and the concentration of the elastically active chain were determined. After reduction of the disulfide bonds of CYS, the presence of thiol side groups was also detected. To determine the concentration of the reactive cross-linkers in the hydrogels, a new method based on the examination of the swelling behavior was established. Using metoprolol as a model drug, cell proliferation and drug release kinetics were studied at different LYS contents and in the presence of thiol groups. The optimal ratio of cross-linkers for the proliferation of periodontal ligament cells was found to be 60−80% LYS and 20−40% CYS. The reductive conditions resulted in an increased drug release due to the cleavage of disulfide bridges in the hydrogels. Consequently, these hydrogels provide new possibilities in the fields of both tissue engineering and controlled drug delivery.

Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

2020 ◽  
Vol 20 ◽  
Author(s):  
Sahil Kumar ◽  
Bandna Sharma ◽  
Tilak R. Bhardwaj ◽  
Rajesh K. Singh
Keyword(s):  
Drug Delivery ◽  
Colon Cancer ◽  
Drug Release ◽  
Anticancer Agents ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Specific Treatment ◽  
Drug Conjugates ◽  
Polymer Drug Conjugates

Aims: In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as anticancer drug specifically to the colon for the proficient treatment of colon cancer. Background: Colon cancer (CC) is the third commonly detected tumor worldwide and it make up about 10 % of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches. Objective: The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to polymeric backbone to give desired polymer linked prodrug. The azo reductase enzyme present in colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon. Methods: The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azobond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions. Results: The synthesized conjugates were demonstrated to be stable in simulated upper gastro-intestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release. Conclusion: These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be the promising candidates for the site-specific treatment of colon cancer with least detrimental side-effects.

scholarly journals COMPARATIVE EVALUATION OF SELECTED POLYMERS AND PLASTICIZER ON TRANSDERMAL DRUG DELIVERY SYSTEM

2018 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Bhawana Sethi ◽  
Rupa Mazumder
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Propylene Glycol ◽  
Drug Delivery System ◽  
Transdermal Drug Delivery ◽  
Release Kinetics ◽  
Content Uniformity ◽  
Transdermal Drug Delivery System ◽  
Transdermal Patches

Objective: The present work was aimed at preparation of transdermal patches by a solvent casting method using a varying concentration of polymers i.e. methocel (K15 and K100), ethocel (4 and 10), gelatin, chitosan, eudragit (RL and RS) grade using plasticizer (glycerin and propylene glycol).Methods: The ratio of drug to polymers and plasticizer was varied and the effect of formulation variables was studied. Prepared transdermal patches were evaluated for physicochemical properties, in-vitro permeation studies, content uniformity, primary skin irritation studies and FT-IR studies.Results: The formulated transdermal patch by using Methocel K 100 M showed good physical properties. The average weight of patches prepared using glycerin as a plasticizer were ranged from 42.33-67.00 mg and propylene glycol as a plasticizer were ranged from 40.67-67.67 mg. The percentage moisture absorption varies from 1.76 to 10.73 for patches formulated using glycerin and 2.28 to 7.97 for propylene glycol patches. The percentage moisture loss from patches prepared using glycerin was ranged from 2.75 to 11.54 and 2.87 to 12.02 from propylene glycol. The water vapour transmission rate from patches prepared using glycerin was ranged from 0.25 to 0.92 and 0.41 to 1.76. The formulated patch showed the acceptable quantity of medicament ranged from (100.20-101.05%). This result met the test content uniformity as per BP (85% to 115%). According to that, the drug was consistent throughout the patches. The formulation PGD is considered as the best formulation, since it shows a maximum in vitro drug release as 43.75 % at 24 h. The drug release kinetics studied showed that the majority of formulations was following zero order.Conclusion: In conclusion, controlled release transdermal drug delivery system patches of aliskiren can be prepared using polymer combinations, with a different plasticizer. The release rate of drug depends upon the polymer. However, release kinetics followed zero order.

Synthesis, characterization and formulation of sodium calcium silicate bioceramic for drug delivery applications

2016 ◽  
Vol 23 (4) ◽  
pp. 375-380
Author(s):  
P. Manohar Reddy ◽  
Ravy Lakshmi ◽  
Febin Prabhu Dass ◽  
Swamiappan Sasikumar
Keyword(s):  
Drug Delivery ◽  
Calcium Silicate ◽  
Release Kinetics ◽  
Release Profile ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
Drug Release Profile ◽  
Sodium Calcium ◽  
Calcium Magnesium ◽  
Model Drug

AbstractSodium calcium silicate (Na2CaSiO4) is a bioactive silicate with Na2O, CaO and SiO2 as its basic components, which is similar to that of the composition of bioactive glasses. In the present study, pure sodium calcium silicate was synthesized by rapid combustion technique, and the synthesized sample was characterized by powder X-ray diffraction to check the phase purity. The scaffolds were prepared by varying the ratio of sodium calcium silicate and polyvinyl alcohol, and the apatite-formation ability of the scaffolds was examined by soaking them in a simulated body fluid. The results revealed the formation of hydroxyapatite on the surface of the scaffold after 5 days, which is found to be rapid when compared with the bioactivity of the calcium silicates and calcium magnesium silicates. The scaffolds were also loaded with ciprofloxacin as a model drug and analyzed for its drug release profile using UV spectrophotometer. The release profile did not vary with the change in bioceramic-to-biopolymer ratio, and 60% of the drug was released in 10 days, which is within the appreciable range for a targeted drug delivery system. Moreover, the experimental and simulated values of the release kinetics were compared by applying the existing mathematical model.

Preparation and Characterization of Biopolymeric Nanoparticles as Drug Delivery Vehicles

2017 ◽  
pp. 225-246
Author(s):  
Sai S. Sagiri ◽  
Suraj K. Nayak ◽  
S. Lakshmi ◽  
Kunal Pal
Keyword(s):  
Drug Delivery ◽  
Salicylic Acid ◽  
Drug Release ◽  
Chitosan Nanoparticles ◽  
Xrd Analysis ◽  
Gelatin Nanoparticles ◽  
Drug Delivery Vehicles ◽  
Model Drug ◽  
Bioactive Agents

In recent years, the use of biopolymeric nanoparticles as vehicles for drug delivery has increased exponentially. In the present study, chitosan and gelatin nanoparticles were prepared by ionic gelation and desolvation methods, respectively. Salicylic acid was used as the model drug. The nanoparticles were characterized using SEM, XRD analysis and FTIR spectrophotometric studies. In vitro drug release experiments were carried out to understand the mechanism of drug release. SEM micrographs showed the formation of spherical nanoparticles. XRD studies indicated a higher crystalline nature of the chitosan nanoparticles as compared to the gelatin nanoparticles. FTIR studies indicated the presence of salicylic acid within the drug- loaded nanoparticles. Drug release studies indicated that the developed nanoparticles may be used as carriers for various bioactive agents.

scholarly journals Spray-Formed Layered Polymer Microneedles for Controlled Biphasic Drug Delivery

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 369 ◽  
Author(s):  
Seok Park ◽  
Min Kim ◽  
Seung-Ki Baek ◽  
Jung-Hwan Park ◽  
Seong-O Choi
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Diffusion Barrier ◽  
Structural Changes ◽  
Tertiary Structure ◽  
Ex Vivo ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Transdermal Drug Delivery System ◽  
Initial Burst

In this study we present polymeric microneedles composed of multiple layers to control drug release kinetics. Layered microneedles were fabricated by spraying poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP) in sequence, and were characterized by mechanical testing and ex vivo skin insertion tests. The compression test demonstrated that no noticeable layer separation occurred, indicating good adhesion between PLGA and PVP layers. Histological examination confirmed that the microneedles were successfully inserted into the skin and indicated biphasic release of dyes incorporated within microneedle matrices. Structural changes of a model protein drug, bovine serum albumin (BSA), in PLGA and PVP matrices were examined by circular dichroism (CD) and fluorescence spectroscopy. The results showed that the tertiary structure of BSA was well maintained in both PLGA and PVP layers while the secondary structures were slightly changed during microneedle fabrication. In vitro release studies showed that over 60% of BSA in the PLGA layer was released within 1 h, followed by continuous slow release over the course of the experiments (7 days), while BSA in the PVP layer was completely released within 0.5 h. The initial burst of BSA from PLGA was further controlled by depositing a blank PLGA layer prior to forming the PLGA layer containing BSA. The blank PLGA layer acted as a diffusion barrier, resulting in a reduced initial burst. The formation of the PLGA diffusion barrier was visualized using confocal microscopy. Our results suggest that the spray-formed multilayer microneedles could be an attractive transdermal drug delivery system that is capable of modulating a drug release profile.

Drug-loaded emulsion electrospun nanofibers: characterization, drug release and in vitro biocompatibility

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 100256-100267 ◽  
Author(s):  
Jue Hu ◽  
Molamma P. Prabhakaran ◽  
Lingling Tian ◽  
Xin Ding ◽  
Seeram Ramakrishna
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Drug Release ◽  
Electrospun Nanofibers ◽  
Tissue Engineering Scaffold ◽  
In Vitro Biocompatibility

Emulsion electrospun drug–PCL nanofibrous mats were demonstrated as better drug delivery substrates and tissue engineering scaffold compared to PHBV nanofibers.

scholarly journals Ranitidine Loaded Biopolymer Floats: Designing, Characterization, and Evaluation

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Abdul Karim ◽  
Muhammad Ashraf Shaheen ◽  
Tahir Mehmood ◽  
Abdul Rauf Raza ◽  
Musadiq Aziz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Lag Time ◽  
Zero Order ◽  
Release Profile ◽  
Drug Release Profile ◽  
Independent Variables ◽  
Zero Order Kinetics ◽  
Model Drug ◽  
Predicted Values

The float formulation is a strategy to improve the bioavailability of drugs by gastroretentive drug delivery system (GRDDS). A drug delivery model based on swellable and reswellable low density biopolymers has been designed to evaluate its drug release profile using ranitidine (RNT) as a model drug and formulations have been prepared utilizing 32factorial designs. The drug release (DR) data has been subjected to various kinetic models to investigate the DR mechanism. A reduction in rate has been observed by expanding the amounts of PSG and LSG parts, while an expansion has been noted by increasing the concentration of tragacanth (TG) and citric acid (CA) with an increment in floating time. The stearic acid (SA) has been used to decrease the lag time because a decrease in density of system was observed. The kinetic analysis showed that the optimized formulation (S4F3) followed zero-order kinetics and power law was found to be best fitted due to its minimum lag time and maximum floating ability. The resemblance of observed and predicted values indicated the validity of derived equations for evaluating the effect of independent variables while kinetic study demonstrated that the applied models are feasible for evaluating and developing float for RNT.

scholarly journals Near-infrared luminescent CaTiO3:Nd3+ nanofibers with tunable and trackable drug release kinetics

2015 ◽  
Vol 3 (37) ◽  
pp. 7449-7456 ◽  
Author(s):  
Xiang Li ◽  
Qiuhong Zhang ◽  
Zeeshan Ahmad ◽  
Jie Huang ◽  
Zhaohui Ren ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Near Infrared ◽  
Release Kinetics ◽  
Drug Release Kinetics ◽  
Nir Emission ◽  
Delivery Platform

Nd3+ doped CaTiO3 nanostructures serve as a promising drug delivery platform with the potential to monitor drug release kinetics by detecting the tissue-penetrating NIR emission.

Amino Acid Functional Polymers: Biomimetic Polymer Design Enabling Catalysis, Chiral Materials, and Drug Delivery

2016 ◽  
Vol 69 (7) ◽  
pp. 705 ◽  
Author(s):  
Emma R. L. Brisson ◽  
Zeyun Xiao ◽  
Luke A. Connal
Keyword(s):  
Drug Delivery ◽  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Building Blocks ◽  
Functional Polymers ◽  
Responsive Materials ◽  
Biomimetic Polymer ◽  
Tunable Optical Properties ◽  
Natural Building

Amino acids are the natural building blocks for the world around us. Highly functional, these small molecules have unique catalytic properties, chirality, and biocompatibility. Imparting these properties to surfaces and other macromolecules is highly sought after and represents a fast-growing field. Polymers functionalized with amino acids in the side chains have tunable optical properties, pH responsiveness, biocompatibility, structure and self-assembly properties. Herein, we review the synthesis of amino acid functional polymers, discuss manipulation of available strategies to achieve the desired responsive materials, and summarize some exciting applications in catalysis, chiral particles, and drug delivery.

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