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The morbidity and mortality of gastrointestinal malignancies are the highest in the world. For patients with poor response to conventional chemotherapy, new treatment methods are urgently needed. In recent years, under the background of precision medicine, antibody-drug conjugates (ADCs) with high tumor specificity and potent toxicity have become a hot research spot in the field of biomedicine. However, due to the complex structure and mechanism of ADCs, its pharmacokinetic research is facing great challenges which are the biggest resistance to the development of ADCs at present. In this case, it is of great significance to understand the pharmacokinetic properties of ADCs and make use of it to improve the efficacy of ADCs in the treatment of gastrointestinal malignancies. Based on the basic composition and mechanism of ADCs, this review summarizes the pharmacokinetic properties of ADCs, discusses its recent advances in the treatment of gastrointestinal malignancies, in order to provide more references for follow-up research on ADCs.
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@#To construct PTEN/PLGA-(HE)10-MAP nanoparticles, which encapsulated PTEN plasmid DNA and combined with the pH-responsive cell-penetrating peptides (CPPs), and to investigate their effects of gene delivery and anti-tumor targets in vitro. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with PTEN plasmid DNA were prepared by double emulsification-solvent evaporation method. PTEN/PLGA-(HE)10-MAP nanoparticles were prepared by coupling the histidine-glutamic acid-model amphipathic peptide nanocomplex [(HE)10-MAP] to the surface through amide condensation reaction. Particle size, Zeta potential, encapsulation rate and drug loading were tested to characterize the nanoparticles. By analyzing the cytotoxicity, cellular uptake, targeted transfection of eukaryotic expression plasmids and anti-tumor cell proliferation, the feasibility as a targeted gene delivery system were evaluated. The particle size of PTEN/PLGA-(HE)10-MAP nanoparticles was (266.5 ± 2.86) nm, with the encapsulation efficiency (80.6 ± 6.11)%. Zeta potentials were -(6.7 ± 0.26) mV, +(0.7 ± 0.22) mV and +(37.5 ± 0.85) mV at pH 7.4, 7.0 and 6.5, respectively. In the cytotoxicity test, the cell survival rates of tumor and normal cells were above 80%.Non-loading PLGA-(HE)10-MAP nanoparticles showed no obvious cytotoxicity. The results of cellular uptake experiments showed that PTEN/PLGA-(HE)10-MAP nanoparticles were more readily taken up by cells.The results of CCK-8 showed that the nanoparticles could pH-specifically inhibit proliferation of tumor cell in vitro.And PTEN/PLGA-(HE)10-MAP nanoparticles may be applied in tumor gene therapy.
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Selective occlusion of tumor vasculature has proven to be an effective strategy for cancer therapy. Among vascular coagulation agents, the extracellular domain of coagulation-inducing protein tissue factor, truncated tissue factor (tTF), is the most widely used. Since the truncated protein exhibits no coagulation activity and is rapidly cleared in the circulation, free tTF cannot be used for cancer treatment on its own but must be combined with other moieties. We here developed a novel, tumor-specific tTF delivery system through coupling tTF with the DNA aptamer, AS1411, which selectively binds to nucleolin receptors overexpressing on the surface of tumor vascular endothelial cells and is specifically cytotoxic to target cells. Systemic administration of the tTF-AS1411 conjugates into tumor-bearing animals induced intravascular thrombosis solely in tumors, thus reducing tumor blood supply and inducing tumor necrosis without apparent side effects. This conjugate represents a uniquely attractive candidate for the clinical translation of vessel occlusion agent for cancer therapy.
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Core-shell-type lipid-polymer hybrid nanoparticles (CSLPHNs) are composed by a biodegradable polymeric core coated with single or multiple layers of biomimetic lipids ,which combine the benefits of polymeric nanoparticles and lipo-somes .CSLPHNs have the advantages of small particle size ,high drug loading ,good biocompatibility and controlled release capability .It has wide applications as a novel drug delivery system .This review gives a brief introduction in characteristics , preparation methods and applications of CSLPHNs ,specifically summarizes the developments in the fields of ophthalmic drug delivery ,tumor therapy and medical diagnostic imaging .
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Trastuzumab is a humanized monoclonal antibody that targets at human epidermal growth factor receptor 2(Her2)proto-oncogenes,which can act on Her2 over-expression of tumor cells,inhibits tumor cells proliferation, differentiation,migration and other physiological activities,reduces the risk of tumor metastasis and extend the sur-vival time of patients.
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OBJECTIVE:To evaluate the affordability of 3 anti-tumor targeted drugs gefitinib,trastuzumab and sunitinib in ur-ban and rural residents of Hubei province,and to provide reference for medical insurance price admission of anti-malignant tumor targeted drugs in China. METHODS:Referring to the incidence of malignant tumor stated in statistical yearbook of Hubei province and income data of urban and rural residents in Hubei province,based on the policy of reducing the price of imported drugs by 50% mentioned in the national drug price negotiations,and assume the drugs are included in the medical insurance reimbursement list,WHO/HAI standard survey method,catastrophic expenditure evaluation method and poverty effect evaluation method were ad-opted to calculate the affordability of 3 drugs. RESULTS:According to WHO/HAI standard survey method,increment of payment for 3 drugs were 64.00%-74.00% before and after 50% discount and reimbursement. According to catastrophic expenditure evalua-tion method,50% discount of gefitinib and reimbursement gefitinib,trastuzumab and sunitinib in urban area would result in cata-strophic expenditures of 20.00%、59.28% and 35.48% patients;in rural area,would result in catastrophic expenditures of 50.63%、74.72% and 75.93% patients. According to poverty effect evaluation method,50% discount of 3 drugs and reimbursement caused less than 31.95% urban and rural patients falling to poverty. CONCLUSIONS:Fifty percentage discount of 3 anti-tumor targeted drugs mentioned in the national drug price negotiations cause the economic burden more serious for rural residents than urban resi-dents. In the formulation of policies,the corresponding reimbursement ratio should be adjusted according to urban and rural areas, drug price and disease types for a balance of patients with different economic burden.
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Objective: To analyze the New Cooperative Medical System ( NCMS ) funds and Individual afford-ability of anti-tumor targeted drugs under different medical insurance entry price, and to provide the basis for establis-hing the access price for medical insurance. Methods: Choosing Conmana or Kemer ( the lung cancer targeted drug) and Herceptin (breast cancer targeted drug) to analyze the Wuhan NRCMS operating status from 2012 to 2014, use tumor surveillance data from Hubei Province during the period from 2011 to 2015;consult clinical experts to form expert consensus price, refer to the Jiangsu Province Access Price and National Negotiation Price, and explore the fund bal-ance and individual affordability when the afore-mentioned two kinds of drugs can be compensated by medical insurance under different price. Results:The basic account balances of NRCMS in Wuhan from 2016 to 2018 are-11. 948 million Yuan, 2. 513 million Yuan and 82. 955 million Yuan when Kemer can be compensated by medical insurance under Na-tional Negotiation Price. Taking the compensation of Herceptin under National Price after the bargaining, the basic ac-count balances are -26. 901 million Yuan,-35. 962 million Yuan and 17. 542 million Yuan respectively. The rate of poverty caused by illness falls to 33. 40% from 45. 85% when Conmana can be compensated by Medical Insurance un-der National Negotiation Price, while this rate falls to 45. 42% from 46. 00% for Herceptin. Conclusion:The two kinds of drugs can be afforded by the Wuhan NRCMS after the medical insurance access price is negotiated by the govern-ment, but the individual affordability of Herceptin at the National Negotiation Price is worse.
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Objective Folate receptors ( FRs) , overexpressed on the surface of a variety of tumor cells , are potential targets for tumor targeting therapy .This study aimed to prepare an FR-mediated drug nanocarrier with folate conjugated pullulan acetate ( FPA) to target chemotherapeutic agents to FR-overexpressed tumor cells and investigate its tumor-suppressing effect in vitro. Methods The cytotoxicity of epirubicin-loaded FPA nanoparticles ( FPA/EPI NP) against HepG2 and Hela cells was evaluated by MTS assay.The HepG2 and Hela cells were divided into five groups to be treated with NPs (NP control), chlorpromazine, chloro-quine, amiloride, and folate, respectively, followed by detection of the fluorescence intensity by flow cytometry . Results FPA/EPI NP was successfully formulated into NPs , with the mean particle size of (268.5 ±12.0) nm, by dialysis with an almost spherical shape . The drug-loading rate and entrapment rate of FPA/EPI NP were (6.45 ±1.04) and (72.45 ±11.50) %, respectively.The survival rates of the HepG2 and Hela cells were both >95%after 24 hours of incubation with FPA NP at 5, 40, 200, 400 and 1000μg/mL and 90.0%after 72 hours.The survival rates of the HepG2 cells treated with 5, 40, 200, 400 and 1000μg/mL FPA/EPI NP for 24 hours were (92.3 ±5.2), (70.4 ±4.6), (50.0 ±4.0), (41.1 ±4.1) and (27.0 ±3.6) %, respectively.Compared with the NP control group, the Hela cells of the chlorpromazine , amiloride and folate groups showed a significantly lower rate of NP uptake (P<0.05), and so did the HepG2 cells pretreated with chlorpromazine or amilo-ride (P<0.05).At 72 hours, the half maximal inhibitory concentrations (IC50) of FPA/EPI NP against HepG2 and Hela cells were 168 and 105μg/mL, respectively . Conclusion Clathrin-mediated endocytosis and macropinocytosis are involved in the internaliza-tion of FPA/EPI NP in HepG2 cells, while clathrin-and FR-mediated endocytosis in that of Hela cells .FPA NP may serve as a new drug carrier for tumor-targeted therapy .
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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.