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Background: Knowledge of newer and targeted drug delivery system is essential for applying pharmacology in treating various clinical conditions. Using appropriate dosage form considering patient抯 age, comorbidities, socioeconomic status, literacy, severity of clinical condition will enhance the effect of drug, decrease the adverse reactions and improve the patient抯 compliance. Learning is most effective when student involvement, participation, and interaction is maximized. Aim and Objectives: To evaluate improvement in knowledge of 2nd year MBBS students for availability, use and necessity of different dosage forms and newer and targeted drug delivery system by assignment based learning. Materials and Methods: The assignment-based activity was conducted for 2nd year MBBS students on different dosage forms and newer and targeted drug delivery system. Seventy students were divided into seven groups and assigned seven questions. Pre-test and post-test were conducted. Results: Post-test results were significantly higher than the pre-test results when compared by paired t-test. There was significant difference among the groups when Analysis of variance test was applied. Group 3, 4, 5 and 6 had gathered good information from e-resources about different drugs list of newer and targeted drug delivery system and Group 3 and 4 gathered details of liposomal and radio-pharmaceuticals based newer drug delivery system. Conclusion: Assignment based activities should be carried out for the critical topics where recent advances are going on, newer techniques for treatment are developing and newer dosage forms are marketed. Through this activity students with poor performance can be identified and guided personally and encouraged for better performance to be a competent physician.
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OBJECTIVE To prepare and evalu ate doxorubicin-loaded red blood cell membrane chitosan-targeted nanoparticles of targeting tumor cell folate acid （FA）receptor（FA-RBC-DOX-CS-NPs）. METHODS Doxorubicin-loaded chitosan nanoparticles （DOX-CS-NPs） were prepared by ion cross-linking method. FA and amino polyethylene glycol phospholithin （NH2- PEG2000-DSPE）were covalently linked to modify the red blood cell membrane to construct FA-RBC-DOX-CS-NPS. FA-RBC- DOX-CS-NPs were characterized and investigated on in vitro drug release characteristics ，antitumor activity and endocytosis ability （investigation with human breast cancer MCF- 7 cells）. RESULTS Average particle size of FA-RBC-DOX-CS-NPs was （254.200± 2.651）nm，and polydispersity index was 0.199±0.031；Zeta potential was （－10.100±0.213）mV. FA-RBC-DOX-CS-NPs released fast in the tumor microenvironment （pH6.5）. Cellular experiments showed that ，the nanoparticles could inhibit the activity of MCF- 7 cell proliferation and improve the efficiency of endocytosis. CONCLUSIONS FA-RBC-DOX-CS-NPs are prepared successfully. The nanoparticles have good tumor cell targeting and endocytosis ability ，and can realize the enrichment of drugs in tumor cells.
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In this study, exosomes were extracted from human malignant melanoma cell A375. Folic acid (FA) receptor was used as target and triptolide (TPL) was used as model drug to prepare exosome targeted drug delivery system, FA-Exo/TPL. The physicochemical properties and antitumor effect were evaluated in vivo and in vitro. Gradient centrifugation method was applied to collect exosomes. Then, exosome was modified with FA for loading TPL. The particle sizes of the FA-Exo/TPL were about 100 nm with a double-layer membrane structure like a tray. It is characteristic of high encapsulation efficiency and drug loading. In vitro experiments showed that FA-Exo/TPL could be effectively uptaken by A375 cells, thus significantly inhibiting proliferation and promoting apoptosis the cells. In vivo experiment results showed that FA-Exo/TPL could effectively inhibit the growth of tumor tissue, prolong the model mice life cycle, and significantly reduce the systemic toxicity of the free drug, playing a synergistic and toxic role. Animal welfare and experimental procedures follow the regulations of the Animal Ethics Committee of Fudan University Shanghai Cancer Center. This study provides a new strategies and methods for the preparation of TPL against malignant melanoma.
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The small size， moderate drug loading， and targeting properties of nano-preparations make them can be excellent delivery tools for drugs， genes or proteins crossing the cell or blood-brain barrier （BBB）. Currently， facilitating drug crossing BBB with innovative nano-drug delivery systems is considered as a strategic approach for the prevention， diagnosis and treatment of central nervous system （CNS） diseases. However， with the deepening of the research， the adverse reactions and toxicity of nanocarriers have gradually attracted the attention of researchers. Based on this， this paper summarized the situation of BBB-penetrating targeted nano-preparations at home and abroad in recent years from the perspective of classification of types and properties of nanocarriers， and analyzed the advantages and disadvantages of each carrier. The results showed that nano-preparations with active ingredients of traditional Chinese medicine （TCM） as carriers have become a promising way of cancer treatment， but the complexity and diversity of TCM components limited its application to a certain extent. Further studies should be strengthened to lay a foundation for the application and development of TCM nano-preparations in the field of CNS diseases.
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Tumor has become the second most serious disease that threatens human health and life. Treating with chemical drugs (referred to as chemotherapy) is the most basic treatment, but most chemotherapeutic drugs cause damage to normal tissues. It is a difficult problem in the field of biomedical research that how to deliver anti-tumor drugs more efficiently, increase the concentration of drugs in tumor tissues, enhance the anti-tumor effect, and decrease the drug distribution in normal tissues to weaken the damage to normal tissues. In order to achieve the goals of accurate delivery of anti-tumor drugs and synergism and attenuation, the researchers used systematic evolution of ligands by exponential enrichment technology (SELEX technology) to screen aptamers that can specifically target tumor markers or tumor cells, and designed the novel liposome targeting drug delivery system with aptamers as targeting molecules (ligands). This paper briefly introduced nucleic acid aptamer technology and common tumor markers, and reviewed the research advances on the antitumor effect of aptamer-liposome drug delivery system. It will provide references for the selection of appropriate tumor markers as targets and the application of aptamer technology in the research and development of high-efficiency and low-toxicity liposome targeting agents of anti-tumor traditional Chinese medicine. Meanwhile, it is of great significance for promoting the application of aptamer technology in targeted drug delivery systems.
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Central nervous system (CNS) diseases are serious threats to human health. Blood-brain barrier (BBB) plays an important role in protecting the CNS. However, it also impedes the delivery of drugs to CNS and affects the treatment of CNS diseases. Brain targeted nano-drug delivery systems provide the possibility to brain-targeting drug delivery. In this article, we introduce the physiological structure and functions of BBB, and the brain targeting mechanism and the applications of brain-targeting nano-vectors to give a brief overview of the research status of brain targeting nano-drug delivery system.
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Central nervous system(CNS)diseases are serious threats to human health. Blood-brain barrier(BBB)plays an im?portant role in protecting the CNS. However,it also impedes the delivery of drugs to CNS and affects the treatment of CNS diseases. Brain targeted nano-drug delivery systems provide the possibility to brain-targeting drug delivery. In this article,we introduce the phys?iological structure and functions of BBB,and the brain targeting mechanism and the applications of brain-targeting nano-vectors to give a brief overview of the research status of brain targeting nano-drug delivery system.
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Due to the complications of Chinese materia medica (CMM) and its preparations, traditional sampling methods have some limitations and affect the analysis on the ingredients of CMM. The review mainly introduced the principles, system compositions, characteristics of the microdialysis technique according to 70 literatures in the late 10 years, especially its applications on the analysis on CMM in vivo, such as in brain, skin, blood, eyes, intestinal, joint, liver, gallbladder kidney, and lung. Among these organs, brain and skin studies have more experiences. As a sampling method, microdialysis technique can not only reveal the change process of ingredients in CMM, but also can help the development of targeted drug delivery, which has the great value and good perspective in the modernization study on CMM.
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With rapid development of modern science and technology, much progress has been made in novel drug delivery system of Chinese materia medica (CMM), combined with new polymer materials and multidisciplinary knowledge. Compared with the traditional preparation, novel drug delivery system in drug distribution in vivo presented high selectivity. In addition, there was no clear correlation between drug concentration in blood and efficacy. Pharmacokinetic process in local target in effect should therefore be systematically investigated. In this article, the author reviewed the means and technology of local pharmacokinetic study on novel drug delivery system for CMM, as well as progress made, and further discussed the developmental issues and challenges.
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DDP could be easily incorporated into poly (?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond. The yield of DDP incorporation into the ?-PGA was 9.4%～10.2%. The DDP was released in the initial 8h in a burst manner,and thereafter in a sustained manner. The results that the conjugation of DDP to poly (?-glutamic acid)-D-galactose esterifiable derivative not only reduced the toxicity of the DDP but also enhanced antitumor activity and the targeting ability. The vivo experiments conclusively established that the ?-D+-DDP compound was much less toxic to animals than DDP alone. A direct evaluation showed that mice treated with ?-D+-DDP compound at a dose of 7.5 mg/kg displayed significant tumor regression. Furthermore,the implanted solid tumors disappeared completely from 35% of the H22 tumor-bearing mice after ?-D+-DDP compound administration. The aforementioned results of biodistributions of the prepared ?-D+-DDP compound in various organs in normal mice demonstrated that the ?-D+-DDP compound had a specific interaction with liver's parenchymal cells and H22 hepatocellular carcinoma tumor cells via ligand receptor recognition. In conclusion,the results indicated that the ?-D+-DDP compound prepared can effectively target the site of hepatoma tumor via the recognition and significantly reduce its size. The ?-D+-DDP compound was less toxic than the free DDP,and could effectively reduce xenografted H22 hepatocellular carcinoma cells in KM mice and prolong the survival of KM mice grafted with H22 hepatocellular carcinoma tumor cells. Therefore,the prepared ?-D+-DDP compound may be used as a potential drug delivery system for the targeted delivery to liver cancers or other liver diseases.