ABSTRACT
Local drug delivery is a new strategy to prevent postoperative recurrence of cancer, thermosensitive gel is a typical topical drug delivery system. In this study, a novel paclitaxel thermosensitive gel (PTG) was prepared to prevent recurrence after chemotherapy for cancer, the effects of drug particle size on release and absorption rate in vivo were investigated. Paclitaxel suspensions with different particle sizes were prepared by medium grinding, high pressure homogenization, air crushing and screening. Using poloxamer as the gel matrix and carbomer as the biological adhesive, Box-Behnen was used to optimize the formulation of PTG. The morphology, viscosity, rheological properties and biological adhesion of thermosensitive gel were characterized. The relationship between dissolution and release of thermosensitive gel was investigated by weight loss method, pharmacokinetics was studied in rats. The paclitaxel suspensions with the particle sizes of 350 nm, 800 nm, 3 μm and 9 μm were prepared, 19% poloxamer 407, 4% poloxamer 188 and 0.1% carbomer were used to prepare PTG. The phase transition temperature of thermosensitive gel was 30 to 35 ℃, there was a good linear relationship between in vitro release and gel dissolution. In the pharmacokinetic study, area under the curve (AUC0-t) increased with the decrease of particle size. In general, the PTG prepared in this study can rapidly change into gel under human body temperature, provided with good adhesion. The release rate in vitro is closely related to the particle size, the release rate increased with the decrease of particle size. This study provides data support for preventing postoperative recurrence of cancer. The animal welfare and experimental process in this paper follow the regulations of the Animal Ethics Committee of the Academy of Military Medical Sciences.
ABSTRACT
The advantages of local administration are as follow: release drugs directly at the lesion, increase the drug concentration in lesion location and reduce the side effects of systemic administration. Thermosensitive gel is one of typical local administration agents. It exhibits the different physical characteristics with the change of temperature. It is sol-gel at low temperature or storage temperature, while when the temperature rises to the transition temperature or near the body temperature, it is semisolid gel with a certain viscoelasticity, and can recover rapidly. It can enhance the local adhesion, which prolongs the local retention time of drugs. As a result, thermosensitive gel can control and display the release of drugs, which can significantly improve the bioavailability of drugs. This review summarizes the characteristics of thermosensitive gel, thermosensitive materials, and its application in different parts: nasal cavity, eye, vagina, periodontal, skin, tumor and joint cavity, based on clinical needs.
ABSTRACT
ObjectiveTo explore the role of transient receptor potential vanilloid 1 （TRPV1） channel in reducing cardiomyocyte toxicity of Aconiti Kusnezoffii Radix processed with Chebulae Fructus. MethodH9c2 cardiomyocytes cultured in vitro were used as a model to assess cell viability by methyl thiazolyl tetrazolium （MTT） assay， the expression of TRPV1 mRNA was detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the leakage rate of lactate dehydrogenase （LDH）， the changes of nucleus， reactive oxygen species （ROS）， mitochondrial membrane potential and Ca2+ contents were detected by enzyme linked immunosorbent assay （ELISA）. ResultCompared with the blank group， when the concentration was ≥0.5 g·L-1， the cell viability was significantly decreased （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ were increased， the mitochondrial membrane potential was decreased， and the nucleus was pyknosis or even broken in raw Aconiti Kusnezoffii Radix and Aconiti Kusnezoffii Radix processed with Chebulae Fructus groups. When the concentration was ≥0.5 g·L-1， compared with the same mass concentration of raw Aconiti Kusnezoffii Radix group， the cell viability increased significantly （P<0.01）， the leakage rate of LDH， the release of ROS and Ca2+ decreased， the mitochondrial membrane potential increased， and the nuclear morphology improved in Aconiti Kusnezoffii Radix processed with Chebulae Fructus group. Application of the same mass concentration of raw Aconiti Kusnezoffii Radix to H9c2 cardiomyocytes pretreated with the TRPV1 inhibitor BCTC significantly increased cell viability， decreased leakage rate of LDH， ROS and Ca2+ release， increased mitochondrial membrane potential and improved nuclear pyknosis compared with untreated H9c2 cardiomyocytes. Application of the same mass concentration of Aconiti Kusnezoffii Radix processed with Chebulae Fructus to H9c2 cardiomyocytes pretreated with BCTC decreased cell viability， increased LDH leakage rate， ROS and Ca2+ release， reduced mitochondrial membrane potential compared with untreated H9c2 cardiomyocytes. Real-time PCR results showed that both raw Aconiti Kusnezoffii Radix and Chebulae Fructus decoction could increase the expression of TRPV1 mRNA in cardiomyocytes in a concentration dependent manner. ConclusionRaw Aconiti Kusnezoffii Radix can induce cardiomyocyte apoptosis and cardiotoxicity by activating TRPV1 channel， while Aconiti Kusnezoffii Radix processed with Chebulae Fructus can attenuate the toxicity through TRPV1 channel， which may be related to the synergistic effect of acid components in Chebulae Fructus and alkaloids in Aconiti Kusnezoffii Radix on TRPV1 channel.
ABSTRACT
Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease, listed as a modern refractory disease by the World Health Organization, which is difficult to recover, whereas it is easy to be attacked repeatedly. UC pathogenesis is closely related to gut microbiota dysbiosis. The gut microbiota interacts with bile acids (BAs), short-chain fatty acids (SCFAs), tryptophan, and other metabolism, immune system, intestinal barrier, etc., which regulate each other and affect the occurrence and development of UC. The active ingredients of traditional Chinese medicine (TCM), single herb and its extracts, and formulae can effectively alleviate UC symptoms by regulating the diversity, structure, composition, and metabolites of gut microbiota. In this review, the TCM based on the regulation of gut microbiota in the treatment of UC and its related mechanism for nearly three years was summarized.
ABSTRACT
Lipid raft nanodomains of plasma membrane are rich in saturated lipids‚ cholesterol‚ sphingolipids‚ functioning as multimolecular platforms to recruit signaling and trafficking proteins involved in an array of physiological processes‚ which are critical for regulating signal transduction in cell. The staggering complexity of cell membranes and the transient formation of nanodomains greatly hinder research on lipid rafts by traditional experimental means. Molecular dynamics simulations have provided important insight into the organizational principles of cell membranes recently. Simulated membrane systems are under a transition from simple membrane models to multicomponent systems‚ culminating in realistic models of various cell types. Coarse-grained models have been extensively adopted as a powerful tool to explore membrane organization and interactions between lipids and proteins‚ providing efficient computational speed and enabling complex systems. In this work‚ coarse-grained molecular dynamics simulations with MARTINI force field were performed to build a raft-forming membrane with mixed lipids‚ including negatively charged lipid PIP2. Mixed lipids in this model were spontaneously partitioned into binary-phase membrane during 5 μs simulations by low temperature (295 K) treatment‚ forming lipid ordered (Lo) and liquid-disordered (Ld) nanodomains. Results of membrane thickness‚ lipid distribution‚ membrane fluidity‚ order parameters of the acyl tails‚ radial distribution functions were consistent with simulation and experimental data. Addition of small amounts of PIP2 did not affect the raft formation‚ and it showed remarkable affinity to lipid raft nanodomains. Simulations of the signaling transmembrane protein CD3ε in our raft-forming membranes were further performed to study the protein-lipid interaction as well. Results showed that the cytoplasmic tail of CD3ε was recruited to the Lo/ Ld boundary due to PIP2 binding‚ and this binding was regulated by Ca
ABSTRACT
Depression is a kind of mental disease with main symptoms of low mood and lack of pleasure, which seriously endangers human health. An appropriate depressive animal model is of great significance for the study of depression and new antidepressant drugs, while the suitable selection and matching of experimental animals, modeling methods and evaluation indexes are critical to eva-luate the scientificity and effectiveness of the depressive animal model. The study advance of depressive animal models in the aspects of experimental animal selection, modeling principle and method, characteristics, evaluation indexes and their application in traditional Chinese medicine are summarized through the systematic review of relevant literatures in PubMed, CNKI and other databases. The depressive animal modeling methods utilized in recent studies include stress, glucocorticoid induction, reserpine induction, lipopolysaccharide induction, surgical modeling, gene knockout, joint application modeling methods. Stress method is better to simulate the depressive symptoms of clinical patients, whereas there are some deficiencies, such as long modeling time and large cost. The depressive animal models induced by glucocorticoid, reserpine and lipopolysaccharide have the advantages of short modeling time and good controllability, but with a poor reliability. The pathogenesis of surgical modeling is highly matched with that of clinical depressive patients, whereas it has the defect of long postoperative recovery period. Gene knockout models can be used to study the precise role of specific genes in depression. However, its applicability may be restricted in studies on depression. The joint application modeling method can improve its reliability and accuracy, and attracts more and more attention. This paper provides a reference for the selection of animal models in future studies of pathological mechanism of depression, and screening and evaluation of antidepressant drugs.
Subject(s)
Animals , Humans , Antidepressive Agents , Therapeutic Uses , Depression , Disease Models, Animal , Medicine, Chinese Traditional , Mental Disorders , Drug Therapy , Reproducibility of ResultsABSTRACT
Objective To investigate the protective effects of G CSF on lungs of rats with acute cholangitis and changes in blood TNF and TXA 2/PGI 2 by treating the rats with G CSF. Methods Seventy two Wistar rats were randomized into the control, infected and treated groups. We established the model of cholangitis in the rats with injection of E. coli 25922 into the bile duct. The animals in the treated group were pretreated with G CSF 500 ng/day bid) for 5 days before the E. coli injection. The levels of blood TNF and TXA 2/PGI 2 were measured at the 3rd, 6th and 12th h after the injection. Meanwhile, the morphological changes in lungs of the rats were observed. Results The morphological changes in lungs were milder and levels of blood TNF and TXA 2/PGI 2 were significantly lower in the treated group than in the infected one (P