ABSTRACT
Organic inorganic hybrids present several advantages as drug release systems, such as: high flexibility, high mechanical and thermal resistance, transparency, and low water solubility. These hybrids are synthesized through a chemical route named sol-gel that usually uses as solvente tetrahydrofuran (THF). Objetives: To develop film formers from hybrid materials replacing THF with ethanol, a less toxic solvent for skin application and for the environment. Methods: Four polymers were used: two based on polyethylene oxide (PEO) with molecular weight of 500 and 1900 g mol-1 and two based on polypropylene oxide (PPO), with molecular weight of 400 and 2000 g mol-1. The structural analysis was performed by FTIR, 1H-NMR and 29Si-NMR, and the thermal-mechanical analysis by DSC and TG-DTA. Results: The results of the thermo-mechanical analysis revealed that the solvent replacement did not affect the thermal stability and flexibility of the di-ureasil hybrid. Conclusions: Structural characterization confirmed the formation of hybrids both in THF and in ethanol. Therefore, ethanol is an excellent solvent for the synthesis of these hybrid matrices, since it allows obtaining the same material without changing its characteristics, with some advantages, however, over THF. Furthermore, this paper describes the efficiency of ethanol as a solvent, which is environmentally friendly, to replace THF in the physical-chemical characteristics of these filming former materials.
ABSTRACT
In recent years, the overexpression dopamine (DA) due to the use of addictive drugs has caused concern and urgently needs to be addressed. The method used in our study is known as biomimetic sol-gel synthesis. We undertook the experiment to develop molecularly imprinted xerogel polymers (MIXPs) through template molecules dopamine polymerized with polyethyleneimine (PEI), then self-assembled and crosslinked with tetramethoxysilane (TMOS) in the form of non-covalent hydrogen bonds by using biomimetic sol-gel process, and then eluted template DA will leave a blotting site. Monoamine oxidase immobilized MIXPs (MAO-MIXPs) was obtained by coating monoamine oxidase onto MIXPs. The synthesis optimization of MAO-MIXPs was finally set as the ratio of DA template, PEI and MAO coating (DA 40 mg, PEI 0.6 mL, MAO 2.5 mg·g-1) to achieve highly selective adsorption toward DA in artificial cerebrospinal fluid based on the adsorption performance and degradation performance. The micromorphologies and physical-chemical properties of MAO-MIXPs were characterized by scanning electron microscopy, differential scanning calorimeter and Fourier transform infrared spectroscopy, and then amount of adsorption was calculated with adsorption equation. Simultaneously, the Brunner-Emmet-Teller (BET) and Langmuir model were simulated. It was found that the adsorption behavior tended to be monolayer adsorption. This new molecularly imprinted polymer demonstrated potential dopamine expression regulation for highly selective recognition, adsorption and degradation of dopamine.
ABSTRACT
To establish a method for directional separation of dehydrotumulosic acid from the extracts of Guizhi Fuling Capsule with molecular imprinting technique (MIT). Molecular imprinting polymer (MIP) was prepared by sol-gel process with dehydrotumulosic acid as molecular template to study the absorption property. The dehydrotumulosic acid was achieved from Guizhi Fuling Capsule by one-step separation with polymer as filler. The structure of dehydrotumulosic acid was identified on the basis of the spectral data and physicochemical property. The maximum binding capacity (Qmax) of MIP was 9.10 mg/g measured by Scatchard equation and the purity of dehydrotumulosic acid was 90.76% by HPLC. The established MIT for the directional separation of dehydrotumulosic acid from Guizhi Fuling Capsule is simple and benefit to reducing the solvent use during the separation process, which could offer a novel method for the separation and purification of dehydrotumulosic acid.
ABSTRACT
Paeoniflorin and its derivatives are main active compounds inGui-Zhi Fu-Ling Capsule (GZFLC). In this study, molecular imprinted polymer (MIP) was prepared by sol-gel process to obtain paeoniflorin and its derivatives in GZFLC. The static adsorption capacity of MIP was measured by scatchard equation. The results showed that the maximum apparent absorbing capacity of MIP was 52.28 mg·g-1. One-step separation of paeoniflorin from 4 g methanol samples of GZFLC was 197 mg with the purity of 89.3%. It was concluded that paeoniflorin MIP can be used to separate phaoniforin and its analogues from GZFLC.