Preparation modification strategies for clinical treatment drugs of Parkinson's disease / 药学学报

Parkinson's disease (PD) is a chronic neurodegenerative disease. At present, levodopa and other drugs are mainly used for dopamine supplementation therapy. However, the absorption of levodopa in the gastrointestinal tract is unstable and its half-life is short, and long-term use of levodopa will lead to the end-of-dose deterioration, dyskinesia, the "ON-OFF" phenomenon and other symptoms. Therefore, new preparations need to be developed to improve drug efficacy, reduce side effects or improve compliance of patients. Based on the above clinical needs, this review briefly introduced the preparation modification strategies for the treatment of PD through case analysis, in order to provide references for the research and development of related preparations.

The screening model for dopamine receptor agonists by a dopamine sensor / 药学学报

Parkinson's disease (PD) is a degenerative disease of the central nervous system due to the loss or death of dopaminergic neurons in the substantia nigra. Clinically, levodopa is the most effective and commonly used drug for PD treatment. However, long-term levodopa therapy is prone to motor complications and other side effects caused by excessive peripheral dopamine production, which has become an urgent problem to be solved in PD treatment. Dopamine receptor (DR) agonists are similar to dopamine. They can directly stimulate postsynaptic dopamine receptors, produce the same effect as dopamine, delay the application of levodopa as much as possible, and reduce complications caused by long-term use of levodopa. Therefore, screening effective dopamine receptor agonists has become a key issue in the study and treatment of PD. In order to establish a rapid, stable and reliable method for dopamine receptor agonist screening, this study used the human dopamine receptor 2 (DRD2) gene fused with a circular permuted EGFP (cpEGFP) to construct a recombinant gene, packaged with lentiviral vector, and the vector replaced the parted inner transmembrane domain of the third intracellular loop (ICL3) of genetically-encoded GPCR-activation based (GRAB) sensors. The fluorescence of GPCR-fused cpEGFP is regulated by conformational changes mediated by the interaction of dopamine receptor agonists with GPCRs without altering GPCR activity. The HEK293T cells were infected with viral vector, screened by puromycin to select highly expressed cells. Dopamine receptor agonists (including dopamine, bromocriptine mesylate, cabergoline, pramipexole) were used as positive drugs to explore the best screening and detection conditions, establishing a stable model to evaluate the dopamine receptor agonist. The results showed that the optimal filter for the dopamine receptor agonist in this study was the cell seeding count of 7×104, and the effective concentration of the positive drug was 1-100 µmol·L-1. In addition, pretreated with 10 µmol·L-1 dopamine receptor antagonists (including chlorprothixol hydrochloride, domperidone, and sulpiride), the positive fluorescence signal of overexpressed DRD2-cpEGFP HEK293T cells could not be detected when exposed to 10 µmol·L-1 dopamine receptor agonists, which proved that dopamine receptor antagonists could block the activity of dopamine receptor agonists, so they cannot activate dopamine receptor allosteric, indicating that the model has good specificity and can also be used for the screening and detection of new dopamine receptor antagonists. In summary, the study constructs a stable dopamine sensor detection system, which can effectively screen potential dopamine receptor agonists. The operation procedures are simple and rapid. And it can be used for a large-scale screening providing a fundamental methodology for drug development and PD treatment targeted on DRD2.

Degrading enzyme modified molecularly imprinted xerogel for selective adsorption and degradation of dopamine / 药学学报

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.