scholarly journals Drug-Loaded, Polyurethane Coated Nitinol Stents for the Controlled Release of Docetaxel for the Treatment of Oesophageal Cancer

2021 ◽  
Vol 14 (4) ◽  
pp. 311
Author(s):  
Paris Fouladian ◽  
Qiuyang Jin ◽  
Mohammad Arafat ◽  
Yunmei Song ◽  
Xiuli Guo ◽  
...  

For several decades, self-expanding metal stents (SEMSs) have shown significant clinical success in the palliation of obstructive metastatic oesophageal cancer. However, these conventional oesophageal stents can suffer from stent blockage caused by malignant tumour cell growth. To overcome this challenge, there is growing interest in drug-releasing stents that, in addition to palliation, provide a sustained and localized release of anticancer drugs to minimise tumour growth. Therefore, in this study we prepared and evaluated an oesophageal stent-based drug delivery platform to provide the sustained release of docetaxel (DTX) for the treatment of oesophageal cancer-related obstructions. The DTX-loaded oesophageal stents were fabricated via dip-coating of bare nitinol stents with DTX-polyurethane (PU) solutions to provide PU coated stents with DTX loadings of 1.92 and 2.79% w/w. Mechanical testing of the DTX-PU coated stents revealed that an increase in the drug loading resulted in a reduction in the ultimate tensile strength, toughness and Young’s modulus. In vitro release studies showed a sustained release of DTX, with ~80–90% released over a period of 33 days. While the DTX-loaded stents exhibited good stability to gamma radiation sterilisation, UV sterilisation or accelerated storage at elevated temperatures (40 °C) resulted in significant DTX degradation. Cell proliferation, apoptosis and Western blotting assays revealed that the DTX released from the stents had comparable anticancer activity to pure DTX against oesophageal cancer cells (KYSE-30). This research demonstrates that the dip-coating technique can be considered as a promising approach for the fabrication of drug-eluting stents (DESs) for oesophageal cancer treatment.

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 17
Author(s):  
Mohammad Arafat ◽  
Paris Fouladian ◽  
Anthony Wignall ◽  
Yunmei Song ◽  
Ankit Parikh ◽  
...  

Self-expanding metal stents (SEMSs) are currently the gold standard for the localised management of malignant gastrointestinal (GI) stenosis and/or obstructions. Despite encouraging clinical success, in-stent restenosis caused by tumour growth is a significant challenge. Incorporating chemotherapeutic drugs into GI stents is an emerging strategy to provide localised and sustained release of drugs to intestinal malignant tissues to prevent tumour growth. Therefore, the aim of this work was to develop and evaluate a local GI stent-based delivery system that provides a controlled release of 5-fluorouracil (5FU) over a course of several weeks to months, for the treatment of colorectal cancer and cancer-related stenosis/obstructions. The 5FU-loaded GI stents were fabricated via sequential dip-coating of commercial GI stents with a drug-loaded polyurethane (PU) basecoat and a drug-free poly(ethylene-co-vinyl acetate) (PEVA) topcoat. For comparison, two types of commercial stents were investigated, including bare and silicone (Si) membrane-covered stents. The physicochemical properties of the 5FU-loaded stents were evaluated using photoacoustic Fourier-transform infrared (PA-FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermal analysis. In vitro release studies in biological medium revealed that the 5FU-loaded stents provided a sustained release of drug over the period studied (18 d), and cell viability, cell cycle distribution and apoptosis assays showed that the released 5FU had comparable anticancer activity against human colon cancer cells (HCT-116) to pure 5FU. This study demonstrates that dip-coating is a facile and reliable approach for fabricating drug-eluting stents (DESs) that are promising candidates for the treatment of GI obstructions and/or restenosis.


2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.


2020 ◽  
Vol 17 ◽  
Author(s):  
Manoj Kumar Mishra ◽  
Jitendra Gupta ◽  
Reena Gupta

Background: Methotrexate (MTX) is a water-insoluble, anti-tumor agent, causes adverse effects like bone marrow suppression, chronic interstitial obstructive pulmonary disease, hepatotoxicity, leukopenia, interstitial pneumonitis and nephrotoxicity with slow drug release rate. Objective: The present study was aimed for successfully incorporating of MTX into novel-targeted Pluronic (PEO-PPOPEO tri-block co-polymer) F127 polymeric micelles intended for intravenous administration with improved drug loading and sustained release behavior necessary to achieve better efficacy of MTX. Method: MTX-loaded Pluronic F127 micelles were characterized for critical micelle concentration, particle size and zeta potential, 1H NMR, drug loading, encapsulation efficiency characterization, cell uptake, in-vitro release study along with partition coefficient and solubilization thermodynamics. Results: The micellar formulation resulted in nano size 27.32±1.43nm of PF127/SDS, as compared to Pluronic F127 micelles or PF127/Phosphatidyl choline which were 30.52±1.18nm and 154.35±5.5nm respectively. The uptake of PF127/SDS micellar formulation incorporating Rhodamine 123 in MCF7 cancer cells was found to be higher (84.25%) than PF127/PC, PF127 and MTX i.e. 66.26%, 73.59% and 53% respectively. The in-vitro MTX release from PF127, PF127/SDS and PF127/PC polymeric micelles formulations was observed 69%, 69.5% and 66% at 12 h whereas 80.89%, 77.67% and 78.54% after 24 h respectively and reveals sustained release. MTX loaded PF127/SDS micelles showed high Partition coefficient and negative free energy of solubilization compared to PF127 and PF127/PC which signifies self-assembly behavior and thermodynamic stability towards dissociation to be higher. Conclusion: Finally concluded that MTX loaded PF127/SDS micelles act as a potential anticancer delivery system in comparison to PF127/PC and PF127 to combat against tumor cells by enhancing its cellular uptake targeting with sustained release pattern and reducing the thermodynamic instability. Thus, PF127/SDS micellar formulation can provide a useful alternative dosage form for intravenous administration of MTX.


Author(s):  
RADHARANI PANDA ◽  
KETOUSETUO KUOTSU

Objective: The objective of the current study is to optimize and evaluate the potential of polyethylene glycolylated (PEG) glyceride Labrasol® nanostructured lipid carrier (NLC) composites of methotrexate (MTX) to achieve enhanced sustained release delivery in cancer treatment. Materials and Methods: MTX-NLC was successfully prepared by hot melt emulsification and probe sonication method for spatial and controlled release of this therapeutic agent. Results: The solubility screening of MTX and lipids resulted in the selection of Monostearin as solid lipid, PEGylated glyceride Labrasol® and olive oil as liquid lipids for the formulation of MTX-loaded NLC composites. Particle size, zeta potential, and polydispersity index of both the composites were confirmed using dynamic light scattering, whereby Labrasol® MTX-NLC showed high entrapment efficiency and drug loading. A spherical particle shape with smooth surface of all the composites was confirmed from the scanning electron microscope and transmission electron microscopy analysis. Labrasol® MTX-NLC showed remarkably increased cytotoxic response, augmented cellular uptake, and low half maximal inhibitory concentration value in MCF-7 cells. In vitro release study confirmed that encapsulation of MTX in PEGylated glyceride Labrasol® MTX-NLC resulted in enhanced sustained release of MTX for a period of 48 h. Conclusion: The present study establishes that PEGylated glyceride Labrasol® MTX-NLC can be considered as a promising anticancer delivery system, thereby improving antitumor efficacy of the drug.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Bhavin K. Patel ◽  
Rajesh H. Parikh ◽  
Pooja S. Aboti

Objective. The main objective of the present investigation was to develop and optimize oral sustained release Chitosan nanoparticles (CNs) of rifampicin by design of experiment (DOE). Methodology. CNs were prepared by modified emulsion ionic gelation technique. Here, inclusion of hydrophobic drug moiety in the hydrophilic matrix of polymer is applied for rifampicin delivery using CN. The 23 full-factorial design was employed by selecting the independent variables such as Chitosan concentration (X1), concentration of tripolyphosphate (X2), and homogenization speed (X3) in order to achieve desired particle size with maximum percent entrapment efficiency and drug loading. The design was validated by checkpoint analysis, and formulation was optimized using the desirability function. Results. Particle size, drug entrapment efficiency, and drug loading for the optimized batch were found to be 221.9 nm, 44.17 ± 1.98% W/W, and 42.96 ± 2.91% W/W, respectively. In vitro release data of optimized formulation showed an initial burst followed by slow sustained drug release. Kinetic drug release from CNs was best fitted to Higuchi model. Conclusion. Design of Experiment is an important tool for obtaining desired characteristics of rifampicin loaded CNs. In vitro study suggests that oral sustained release CNs might be an effective drug delivery system for tuberculosis.


2012 ◽  
Vol 482-484 ◽  
pp. 2605-2608 ◽  
Author(s):  
Li Li Ruan ◽  
Da Xin Wang ◽  
You Wei Zhang ◽  
Jiong Xin Zhao ◽  
Xiu Fang Zhang ◽  
...  

In this paper we study in vitro release of paclitaxel-loade polycaprolactone sustained-release microspheres. Different pH values release medium is used to simulate pH conditions in different parts of body, and determination the paclitaxel in Microspheres by High Performance Liquid Chromatography according Chinese Pharmacopoeia 2010. The experimental results indicate that the microspheres release rates of same drug loading content in buffer solution of pH 7.35 is the fastest, and in the pH 1.2 is the slowest. The drug release behavior according to the first-order model and it is not affected by drug loading rate of microspheres. The prepared paclitaxel-loade polycaprolactone sustained-release microspheres has good sustained release effect in different release media, and the results can provide references for further study of in vivo release.


Biomedicines ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 92 ◽  
Author(s):  
Shannon Kelly ◽  
Anjali Hirani ◽  
Vishal Shahidadpury ◽  
Aum Solanki ◽  
Kathleen Halasz ◽  
...  

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the United States, affecting approximately 11 million patients. AMD is caused primarily by an upregulation of vascular endothelial growth factor (VEGF). In recent years, aflibercept injections have been used to combat VEGF. However, this treatment requires frequent intravitreal injections, leading to low patient compliance and several adverse side effects including scarring, increased intraocular pressure, and retinal detachment. Polymeric nanoparticles have demonstrated the ability to deliver a sustained release of drug, thereby reducing the necessary injection frequency. Aflibercept (AFL) was encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) via double emulsion diffusion. Scanning electron microscopy showed the NPs were spherical and dynamic light scattering demonstrated that they were uniformly distributed (PDI < 1). The encapsulation efficiency and drug loading were 75.76% and 7.76% respectively. In vitro release studies showed a sustained release of drug; 75% of drug was released by the NPs in seven days compared to the full payload released in 24 h by the AFL solution. Future ocular in vivo studies are needed to confirm the biological effects of the NPs. Preliminary studies of the proposed aflibercept NPs demonstrated high encapsulation efficiency, a sustained drug release profile, and ideal physical characteristics for AMD treatment. This drug delivery system is an excellent candidate for further characterization using an ocular neovascularization in vivo model.


2017 ◽  
Vol 9 (3) ◽  
pp. 20
Author(s):  
K.v. Ramana Reddy ◽  
M. V. Nagabhushanam

Objective: The aim of the study was to develop and characterize mucoadhesive microbeads for oral sustained release of atorvastatin by using hydrophilic polymers and application of different process variables in designing of pH sensitive swellable microbeads.Methods: Microbeads were prepared by ionic gelation method. The compatibility studies of atorvastatin with polymers were investigated by differential scanning calorimeter and fourier transform infrared spectroscopy studies. In this work process variable like optimization of curing agents and their quantity, effect of rpm, and their influence in drug entrapment were studied. Prepared beads were characterized for particle size, swelling index, erosion studies and drug release studies.Results: Mixture of alginate and carbopol 934 P at 3.3 % w/v shows sustained release and good mucoadhesive capacity. Furthermore, drug loading and swelling increased with the use of a combination of polymers. On basis of in vitro release studies and swelling studies, it was observed that sodium alginate coated with carbopol 934 P showed sustained release of 84.5 % at end of 10 h in 6.8 phosphate buffer. The optimised batch followed peppas and higuchi release mechanism and releasing the drug by non-fickian transport.Conclusion: The alginate beads with a combination of carbopol 934P showed a sustain release pattern. The release rate and swelling of atorvastatin beads could be adjusted by adding other hydrophilic polymers or by optimising curing agents, curing time and their volume. The zero order of drug release was confirmed for all the batches. The in vitro data was better fit to Higuchi’s diffusion model and diffusion rate limited.


Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 2024
Author(s):  
Yi He ◽  
Hongli Li ◽  
Xiangyu Zheng ◽  
Mingwei Yuan ◽  
Renyu Yang ◽  
...  

In order to enrich the types of Panax notoginseng saponins (PNS) sustained-release preparations and provide a new research idea for the research and development of traditional Chinese medicine sustained-release formulations, a series of Panax notoginseng saponins microspheres was prepared by a double emulsion method using a series of degradable amphiphilic macromolecule materials polyethylene glycol monomethyl ether-polymandelic acid (mPEG-PMA) as carrier. The structure and molecular weight of the series of mPEG-PMA were determined by nuclear magnetic resonance spectroscopy (1 HNMR) and gel chromatography (GPC). The results of the appearance, particle size, drug loading and encapsulation efficiency of the drug-loaded microspheres show that the mPEG10000-PMA (1:9) material is more suitable as a carrier for loading the total saponins of Panax notoginseng. The particle size was 2.51 ± 0.21 μm, the drug loading and encapsulation efficiency were 8.54 ± 0.16% and 47.25 ± 1.64%, respectively. The drug-loaded microspheres were used for in vitro release and degradation experiments to investigate the degradation and sustained release behaviour of the drug-loaded microspheres. The biocompatibility of the microspheres was studied by haemolytic, anticoagulant and cytotoxicity experiments. The pharmacological activity of the microspheres was studied by anti-inflammatory and anti-tumour experiments. The results showed that the drug-loaded microspheres could be released stably for about 12 days and degraded within 60 days. At the same time, the microspheres had good biocompatibility, anti-inflammatory and anti-tumour activities.


Author(s):  
Dilip Kumar Gupta ◽  
B K Razdan ◽  
Meenakshi Bajpai

The present study deals with the formulation and evaluation of mefloquine hydrochloride nanoparticles. Mefloquine is a blood schizonticidal quinoline compound, which is indicated for the treatment of mild-to-moderate acute malarial infections caused by mefloquine-susceptible multi-resistant strains of P. falciparum and P. vivax. The purpose of the present work is to minimize the dosing frequency, taste masking toxicity and to improve the therapeutic efficacy by formulating mefloquine HCl nanoparticles. Mefloquine nanoparticles were formulated by emulsion diffusion method using polymer poly(ε-caprolactone) with six different formulations. Nanoparticles were characterized by determining its particle size, polydispersity index, drug entrapment efficiency, drug content, particle morphological character and drug release. The particle size ranged between 100 nm to 240 nm. Drug entrapment efficacy was >95%. The in-vitro release of nanoparticles were carried out which exhibited a sustained release of mefloquine HCl from nanoparticles up to 24 hrs. The results showed that nanoparticles can be a promising drug delivery system for sustained release of mefloquine HCl.


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