scholarly journals Polysaccharide κ-Carrageenan as Doping Agent in Conductive Coatings for Electrochemical Controlled Release of Dexamethasone at Therapeutic Doses

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2139 ◽  
Author(s):  
Karla Ramírez Sánchez ◽  
Aura Ledezma-Espinoza ◽  
Andrés Sánchez-Kopper ◽  
Esteban Avendaño-Soto ◽  
Mónica Prado ◽  
...  
Keyword(s):  
Controlled Release ◽  
Electrical Properties ◽  
High Resolution Mass Spectrometry ◽  
Physical Stability ◽  
Doping Agent ◽  
Release Process ◽  
As Doping ◽  
Organic Bioelectronics ◽  
Bioactive Agents ◽  
Therapeutic Doses

Smart conductive materials are developed in regenerative medicine to promote a controlled release profile of charged bioactive agents in the vicinity of implants. The incorporation and the active electrochemical release of the charged compounds into the organic conductive coating is achieved due to its intrinsic electrical properties. The anti-inflammatory drug dexamethasone was added during the polymerization, and its subsequent release at therapeutic doses was reached by electrical stimulation. In this work, a Poly (3,4-ethylenedioxythiophene): κ-carrageenan: dexamethasone film was prepared, and κ-carrageenan was incorporated to keep the electrochemical and physical stability of the electroactive matrix. The presence of κ-carrageenan and dexamethasone in the conductive film was confirmed by µ-Raman spectroscopy and their effect in the topographic was studied using profilometry. The dexamethasone release process was evaluated by cyclic voltammetry and High-Resolution mass spectrometry. In conclusion, κ-carrageenan as a doping agent improves the electrical properties of the conductive layer allowing the release of dexamethasone at therapeutic levels by electrochemical stimulation, providing a stable system to be used in organic bioelectronics systems.

The Effect of Oxalic Acid as a Doping Agent on the Conductivity of Polyaniline

2016 ◽  
Vol 13 (1) ◽  
pp. 15
Author(s):  
Amirah Amalina Ahmad Tarmizi ◽  
Mohamad Kamal Harun ◽  
Saifollah Abdullah ◽  
Hadariah Bahron ◽  
Muhd Zu Azhan Yahya ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Oxalic Acid ◽  
Oxidizing Agent ◽  
Doping Agent ◽  
Ammonium Persulphate ◽  
As Doping

This study investigates the effect of oxalic acid at different concentrations as doping agent on the electrical properties of polyaniline (PANI). The polymerization of aniline to produce PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and 0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6 Scm-1.

The Effect of Oxalic Acid as a Doping Agent on the Conductivity of Polyaniline

2019 ◽  
Vol 13 (1) ◽  
pp. 15
Author(s):  
Amirah Amalina Ahmad Tarmizi ◽  
Mohamad Kamal Harun ◽  
Saifollah Abdullah ◽  
Hadariah Bahron ◽  
Muhd Zu Azhan Yahya ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Oxalic Acid ◽  
Oxidizing Agent ◽  
Doping Agent ◽  
Ammonium Persulphate ◽  
As Doping

This study investigates the effect of oxalic acid at different concentrations as doping agent on the electrical properties of polyaniline (PANI). The polymerization of aniline to produce PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and 0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6 Scm-1.

Controlled release and corrosion protection by self-assembled colloidal particles electrodeposited onto magnesium alloys

2015 ◽  
Vol 3 (8) ◽  
pp. 1667-1676 ◽  
Author(s):  
Jiadi Sun ◽  
Ye Zhu ◽  
Long Meng ◽  
Wei Wei ◽  
Yang Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Controlled Release ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Colloidal Particles ◽  
Self Assembled ◽  
Bioactive Agents

Self-assembled nanoparticles loaded with bioactive agents were electrodeposited to provide the magnesium alloy with controlled release and corrosion resistance properties.

Preparation of Sodium Paeonolsilate Intercalated into Layered Double Hydroxides and its Release Properties

2015 ◽  
Vol 1095 ◽  
pp. 349-354 ◽  
Author(s):  
Liang Hua Gu ◽  
Hong Qing Song ◽  
Zhi Yong Sun ◽  
Ji Yong Zheng ◽  
Jin Wei Zhang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Release Kinetics ◽  
Molar Ratio ◽  
Burst Release ◽  
X Ray Diffraction ◽  
Release Process ◽  
Rate Determining Step ◽  
Release Ratio ◽  
Double Hydroxide ◽  
Double Hydroxides

A controlled release composite has been prepared by intercalation of sodium paeonolsilate (PAS) into Mg/Al layered double hydroxide (LDH) with the molar ratio (M2+/M3+) of 2:1. The powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) confirm the intercalation of PAS into the galleries of LDH. The chemical composites of PAS-LDH were revealed by elemental analysis. Release tests of the PAS-LDH composite showed that no burst release phenomenon occurred at the beginning stage and a high release ratio of PAS (89.8%) was obtained, exhibiting controlled release behavior. Furthermore, the parabolic diffusion model was used to simulate the release kinetics of PAS from the LDH carrier, indicating that the intraparticle diffusion via ion-exchange is the rate-determining step in the release process. It is significance in this work for introducing the PAS-LDH composite to develop antifouling materials with long-term activity.

Preparation of Redox-Sensitive Shell Cross-Linked Nanoparticles for Controlled Release of Bioactive Agents

2012 ◽  
Vol 1 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Guohua Jiang ◽  
Yin Wang ◽  
Rui Zhang ◽  
Rijing Wang ◽  
Xiaohong Wang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Bioactive Agents

Role of strontium as doping agent in LaMn0.5Ni0.5O3 for oxygen electro-catalysis

2020 ◽  
Vol 85 ◽  
pp. 94-101 ◽  
Author(s):  
Mobinul Islam ◽  
Min-Gi Jeong ◽  
In-Hwan Oh ◽  
Kyung-Wan Nam ◽  
Hun-Gi Jung
Keyword(s):  
Doping Agent ◽  
As Doping ◽  
Electro Catalysis

Preparation and Evaluation of p-Type Materials for a-Si Solar Cells Using DC Plasma Discharge Deposition of Trimethylboron (B(CH3)3)

1989 ◽  
Vol 149 ◽  
Author(s):  
Benjamin F. Fieselmann ◽  
B. Goldstein
Keyword(s):  
Solar Cells ◽  
Electrical Properties ◽  
Plasma Discharge ◽  
Optical And Electrical Properties ◽  
Dc Plasma ◽  
Doping Agent ◽  
Si Solar Cells ◽  
P Type ◽  
Amorphous Sic ◽  
Preparation And Evaluation

ABSTRACTAmorphous SiC p-layers doped with trimethylboron (B(CH3) 3) were prepared with optical and electrical properties superior to those prepared with B2H6. Devices were prepared with efficiencies as high as 11.4% using trimethyl boron. The improved properties of B(CH3)3-doped a-SiC result from the fact that trimethylboron is a more effective doping agent than B2H6 and produces p-layers with a higher bandgap.

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