L-DOPA stabilization on sol–gel silica to be used as neurological nanoreservoirs: Structural and spectroscopic studies

López, T.; Esquivel, Dulce; Mendoza-Dı́az, Guillermo; Ortiz-Islas, Emma; Gonzalez, Richard; Novaro, O.

doi:10.1016/j.matlet.2015.08.015

Cited by 6 publications

(3 citation statements)

References 25 publications

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“…The bands observed at 2924 cm −1 and 2854 cm −1 corresponded to asymmetric and symmetric ―CH 2 ― stretching vibrations, respectively. The bands located between 1300 cm −1 and 1600 cm −1 were C―C bending vibrations of the phenol rings . A shift of 47 cm −1 towards high frequency was noticed with respect to the mBN spectrum, as well as a slight shift of B‐N in‐plane and out‐of‐plane vibrations.…”

Section: Resultsmentioning

confidence: 89%

Surface modification of boron nitride via poly (dopamine) coating and preparation of acrylonitrile‐butadiene‐styrene copolymer/boron nitride composites with enhanced thermal conductivity

Rongfen

Geng

et al. 2017

Polymers for Advanced Techs

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A biology-inspired approach was utilized to functionalize hexagonal boron nitride (h-BN), to enhance the interfacial interactions in acrylonitrile-butadiene-styrene copolymer/boron nitride (ABS/BN) composites. The poly (dopamine), poly (DOPA) layer, was formed on the surface of BN platelets via spontaneously oxidative self-polymerization of DOPA in aqueous solution. The modified BN (named as mBN) coated with poly (DOPA) was mixed with ABS resin by melting.The strong interfacial interactions via π-π stacking plus Van der Waals, both derived from by poly (DOPA), significantly promoted not only the homogeneous dispersion of h-BN in the matrix, but also the effective interfacial stress transfer, leading to improve the impact strength of ABS/mBN even at slight mBN loadings. A high thermal conductivity of 0.501 W/(m·K) was obtained at 20 wt% mBN content, reaching 2.63 times of the value for pure ABS (0.176 W/(m·K)).Meanwhile, the ABS/mBN composites also exhibited an excellent electrical insulation property, which can be expected to be applied in the fields of thermal management and electrical enclosure. Due to superior electrical insulation, good processability, light weight, and low cost, polymers have been widely used in electrical and electronic fields.1 However, the thermal conductivity of typical polymer is far below the demand for heat dissipation. In recent years, some non-covalent methods are explored, which are usually applying physical interaction between the matrix and the fillers such as Van der Waals attractions, electrostatic interactions, π-effects, and hydrogen bonding. [38][39][40][41][42] Compared with covalent methods, non-covalent modification is much more convenient, and it can keep the intrinsic properties of BN away from disruption of extended π-conjugation systems.In this study, BN platelets were functionalized by a non-covalent method with dopamine (DOPA) as a modifier. The poly(DOPA) layer indeed played an important role in enhancing the interfacial interactions between the fillers and the matrix. The thermal conductivity and other properties of ABS/BN composites were discussed. | Surface modification of BNThe poly(DOPA) coated BN (donated as mBN) was prepared in a typical route as follows: 2-g BN was mechanically stirred and sonicated for 2 hours in a 200-mL flask containing a phosphate (Na 2 HPO 4 + KH 2 PO 4 ) buffer solution (PBS, pH 8.5). The pH value was determined by pH meter (PHS-25, Shanghai Scientific Instrument Co., Ltd., China). Then, 0.2-g DOPA was charged into the resulting mixture, followed by vigorously stirring at 28°C for the fixed periods (t = 1, 2, 5, 10, 20 hours) to ensure self-polymerization on the surface of BN platelets. Subsequently, the suspension was filtered through a 0.45-μm membrane and washed several times with deionized water until the filtrate became colorless and neutral to get the modified BN platelets (mBN).The final product was dried in a vacuum oven at 40°C for 24 hours. Figure 1 describes the possible mechanism referred to in some literatures. 43,46 Th...

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Section: Resultsmentioning

confidence: 89%

Surface modification of boron nitride via poly (dopamine) coating and preparation of acrylonitrile‐butadiene‐styrene copolymer/boron nitride composites with enhanced thermal conductivity

Rongfen

Geng

et al. 2017

Polymers for Advanced Techs

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“…This makes the treatment of PD with L-Dopa an ideal candidate for experimentation with drug delivery systems, where a longer lasting, slow and continuous release source of L-Dopa would increase the length of time that L-Dopa remains effective and hence improve the quality of life of patients in the latter stages of care. To meet this goal, different drug delivery systems, such as polymeric nanoparticles and silica nanoparticles have been explored to entrap L-Dopa and improve the release of the drug, but all of them respond to conventional methodologies, in which the L-Dopa is incorporated/loaded into the corresponding matrix porosity in several steps [47][48][49][50][51] . The novelty of this research lies in the preparation L-Dopa@MSN nanoparticles based on the concept of DSDA containing L-Dopa, as the mainstay treatment for PD.…”

Section: Introductionmentioning

confidence: 99%

l-Dopa release from mesoporous silica nanoparticles engineered through the concept of drug-structure-directing agents for Parkinson's disease

et al. 2021

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“…These side effects have been found to be reduced by vitamin B6, but vitamin B6 also reduces the efficiency of levodopa. [7][8][9] The term vitamin B6 or pyridoxine is used to refer to a wide group of rather distinct water-soluble bioactive compounds, which act as an important enzymatic co-factor needed for over 140 bioreactions and play a key role in tolerance against abiotic stress. The presence of OH and NH2 groups in the structure of vitamin B6 gives it the ability to directly react and scavenge peroxy radicals.…”

Section: Introductionmentioning

confidence: 99%

Selective Determination of Levodopa in the Presence of Vitamin B6. Theophylline and Guaifenesin Using a Glassy Carbon Electrode Modified with a Composite of Hematoxylin and Graphene/ZnO

2018

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An electrode has been developed based on using a composite of hematoxylin/graphene/ZnO nanocomposite to modify a glassy carbon electrode (GCE). The electrode (HGGCE) was tested and found to be applicable for the voltammetric analysis of levodopa in the presence of vitamin B, theophylline and guaifenesin using a 0.1 M phosphate buffer solution (PBS) pH 7 as the solvent. The HGGCE was used as the working electrode in cyclic voltammetry (CV) and square wave voltammetry (SWV) studies on the electrochemical behavior of levodopa at its surface. The results showed a dramatic enhancement in the oxidation current of levodopa and a shift in its oxidation potential towards more negative potentials as opposed to identical tests using bare GCE as the working electrode. The studies showed that the increase in the oxidation current has two linear profiles in two concentration ranges of 0.05 - 90.0 and 90.0 - 1000.0 μM. The detection limit of SWV analysis using the modified electrode was determined to be 0.03 μM (S/N = 3). Further advantages of the methods based on HGGCE include the simple modification procedure of the electrode, as well as its excellent sensitivity and reproducibility. The modified electrode was eventually found to be applicable to the determination of mixtures of levodopa, vitamin B, theophylline and guaifenesin in real samples.

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L-DOPA stabilization on sol–gel silica to be used as neurological nanoreservoirs: Structural and spectroscopic studies

Cited by 6 publications

References 25 publications

Surface modification of boron nitride via poly (dopamine) coating and preparation of acrylonitrile‐butadiene‐styrene copolymer/boron nitride composites with enhanced thermal conductivity

Surface modification of boron nitride via poly (dopamine) coating and preparation of acrylonitrile‐butadiene‐styrene copolymer/boron nitride composites with enhanced thermal conductivity

l-Dopa release from mesoporous silica nanoparticles engineered through the concept of drug-structure-directing agents for Parkinson's disease

Selective Determination of Levodopa in the Presence of Vitamin B6. Theophylline and Guaifenesin Using a Glassy Carbon Electrode Modified with a Composite of Hematoxylin and Graphene/ZnO

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