ABSTRACT
Objective To construct a glioma targeting delivery system, PAMAM G5 were modified with the oligopeptide of blood brain barrier (BBB) targeting TGN and tumor targeting oligopeptide iRGD to solve the problem of non-specificity in distribution and difficulty in permeating BBB of ATO, in order to have better anti-glioma effect. Methods The physical and chemical properties of nanocarriers were investigated by 1H-NMR and transmission electron microscopy (TEM); The encapsulation efficiency and in vitro release were analyzed by inductively coupled plasma emission spectrum (ICP) and dialysis bag method; The effects of iRGD and TGN on cellular uptake of the carriers were analyzed by laser confocal and flow cytometry. The cytotoxicity of nanocarriers on brain microvascular endothelial cells (HBMEC) and glioma cells (U87), the inhibition effect on U87 cells of drug delivery systems after acrossing the BBB model in vitro were investigated by MTT method. Results The iRGD/TGN-PEG-PAMAM was synthesized successfully. The TEM results showed that iRGD/TGN-PEG-PAMAM was regular in shape and uniform in size. The particle size of iRGD/TGN-PEG-PAMAM/ATO was (24.87 ± 0.84) nm and the potential was (17.26 ± 1.64) mV. The synthesized carrier had less toxicity to HBMEC and U87 cells. The encapsulation efficiency of iRGD/TGN-PEG-PAMAM/ATO delivery system was (71.92 ± 1.17)%. The in vitro release showed that ATO had a slow release trend after entrapment, and it was more favorable for ATO release under acidic conditions. The cell uptake indicated that iRGD/TGN modification was more beneficial for U87 cell to uptake the drug delivery system. The in vitro inhibition effect on U87 cells after acrossing the BBB model showed iRGD/TGN-PEG-PAMAM/ATO had better inhibition effect on U87 cells. Conclusion The iRGD/TGN-PEG-PAMAM/ATO targeting drug delivery system has good inhibition effect on U87 cells effect after acrossing the BBB model in vitro, which provides a new strategy for the treatment of glioma.
ABSTRACT
The development of pharmaceuticals has been providing many kinds of novel drug delivery systems, which are important for improving therapeutic effect and one of the most important fields in pharmaceutics. According to their application, we can generally divide the novel drug delivery systems into three categories:quickly performed drug delivery system, long-term drug delivery system and high effective drug delivery system. Some diseases, such as asthma, angina pectoris and migraine, require therapeutics urgently, and the drugs have to be absorbed in several minutes. Therefore, quickly performed drug delivery systems are developed, such as oral disintegrating tablets and nasal spray. For normal tablets and capsules, especially the drugs with short blood half life, the drug concentration in blood shows obvious peak-valley phenomenon, which reduces the therapeutic effect and requires multiple administration. To solve this problem, sustained drug release system was developed, which could release the drugs slowly and sustainably even in zero-order kinetics. The pulse drug delivery system was developed that can delayed and pulsed release drug for one or several times. This system is especially useful in the management of asthma and heart disease, which are often found in midnight or early morning when patients are in bed. Transdermal drug delivery system could release drugs sustainably and deliver the drugs through skin to blood circulation, providing long term activity. The water-insoluble drugs are difficult for pharmaceutical development, thus many methods were developed to improve the solubility and bioavailability of drugs. Although biopharmaceuticals are important for disease treatment, the application shadows by the poor stability and low bioavailability. Thus the biopharmaceutical delivery system was developed, which mainly focused on structure modification and encapsulation by carriers. Considering therapeutic effect requires interaction between drugs and their targets, it is important to deliver drugs to their targets. Therefore, targeting delivery systems were developed, which mainly based on the nanoparticles. Furthermore, on-demand release drug delivery systems are also developed with the property of environment-triggered drug release. In conclusion, the novel drug delivery systems were reviewed in this study.
ABSTRACT
Chemotherapy is one of the traditional tumors treatment solutions.Chemotherapy has the feature of tissue non-specificity,which can cause side effects on normal cells while inhibiting tumor cell growth.Magnetic targeting drug delivery system (MTDDS) employs biocompatible and stable magnetic nanoparticles (MNP) as drug carries to transport and accumulate anticancer drugs to the specific tumor tissues under the guidance of external magnetic field.This technology not only improves the efficiency of drug delivery and antitumor activity,but also reduces the drug dosage and side effects.The properties of drug-loaded MNPs and the applied external magnetic field are the main factors that affecting the MNPs targeting to the tumor tissues.The effectiveness of the targeted delivery of the drug-loaded magnetic nanoparticles mainly depends on the form and strength of the magnetic field at the target site.That is,whether there is sufficient strength to attract and retain NMPs,and to promote antitumor drug release at the tumor region.In this paper,the research progress of static magnetic field targeting drug delivery system in tumor diagnosis and therapy was summarized,which can provide some basic information for the relative scientific researches.
ABSTRACT
The purpose of this study is to develop a liposomal drug delivery system actively targeting Cryptococcus neoformans and explore its feasibility in therapy of cryptococcal infection. The specific fungibinding peptide was screened from 12-mer random phage display library, and linked to PEG-DSPE as the functional material of liposomes. The targeting capability of peptide-modified liposomes were investigated by fungi binding assay in vitro and fluorescence imaging in vivo. Itraconazole as a model drug were then encapsulated in the liposomes and were evaluated in pharmacodynamic test in vitro and for therapeutic effects against cryptococcal meningitis complicated with pulmonary cryptococcosis in vivo. The results showed that the peptide (sequence:NNHREPPDHRTS) could selectively recognize Cryptococcus and effectively mediate the corresponding liposomal formulation to accumulate in the infection site in vivo. This peptide-modified liposome has a small particle size (mean diameter of 88.25±2.43 nm) with a homogeneous distribution and high encapsulation efficiency (88.05±0.25%) of itraconazole. After intravenous administration, the pathogens were obviously eliminated in lung and brain, and the life-span of model mice were significantly prolonged, suggesting a promising potential of this cryptococcosis targeting strategy.
ABSTRACT
In recent years, tumor is a refractory disease occurring frequently which is the main cause of death. Surgery, radiotherapy and chemotherapy are the usual therapeutic tools. However,radiotherapy and chemotherapy have serious side-effects and surgery can not be used effectively when metastasis happened. Therefore, tumor-targeted therapy has developed as a better way to cure tumor. Development of research on the use of PEG-PLGA nanoparticles as drug carriers are reviewed in this article, furthermore, problems about that are analysed.
ABSTRACT
Target-oriented drug delivery systems(TODDS) of Chinese materia medicia(CMM) is ascribed as preparations in which active fractions or single ingredient extracted from CMM or natural medicines are directly delivered with the help of different carriers to target organs,target tissues,and target cells or intracellula.Recent advances of research on TODDSs of CMM classified according to carriers,such as liposomes,microspheres,nanocapsules,and emulsions are reviewed.In addition,due to the specific actions of CMM on intestinal diseases,oral colon targeting drug delivery system is considered substantials for TODDSs of CMM.Domestic researches on TODDS of CMM in its initial stage are limited to formulations using single natural active ingredient as raw material.While the fewer TODDSs using CMM active fractions or formula recipes are underway,which relates to the tremendous difficulties in both establishment of quality standard for CMM active fractions and technology for preparation of CMM.Nevertheless one of the important goals for the development on preparation of CMM is TODDS.