BACKGROUND AND PURPOSE: Arginine esterase(Ancrod), a thrombin-like enzyme, purified from the venoms of Agkistrodon halys, has known to cleave fibrinopeptide A from the fibrinogen and lead to circulation of soluble noncross-linked "ancrodfibrin', which stimulates endogenous T-PA release.Many authors have suggested clinical applicability of this enzyme,but clinical studies on its fibrinolytic action has been insufficient.Thus we studied the influence of this enzyme on fibrinolytic activity in cerebral infarction. METHOD: We observed the change of euglobulin fibrinolytic activity, t-PA antigen, t-PA activity, fibrinopeptide A, fibrinogen, FDP and D-dimer, during 12 hours after a bolus intravenous administration of 0.25 unit of the arginine esterase to the 9 patients with cerebral infarction. RESULT:There was no change of the euglobulin fibrinolytic activity, fibrinopeptide A and t-PA Ag but there was significant increase in both t-PA activity and FDP, D-dimer and significant decrease in fibrinogen. CONCLUSION: Our result suggest that arginine esterase converts fibrinogen to a fibrin polymer which has a increased susceptibility to lysis by plasmirl This enzyme seems to amplify T-PA activity through the consequent increase in FT)P, because there is no increase in the euglobulin fibrinolytic activity, fibr'mopeptide A and t-PA Ag suggesting direct T-PA release. Arginine esterase, having action of effective defibrinogenation and safe fibrinolysis,could be used for the thrombus related disease.
Administration, Intravenous ; Agkistrodon ; Arginine ; Cerebral Infarction ; Fibrin ; Fibrinogen ; Fibrinopeptide A ; Humans ; Polymers ; Snake Venoms* ; Snakes* ; Thrombosis ; Venoms

OBJECTIVETo prepare polylactic acid microspheres containing total alkaloid extracts of Caulis sinomenii and study their release characteristics in vitro.

METHODPolylactic acid microspheres containing total alkaloid extracts of C. sinomenii were prepared by O/W emulsification solvent-evaporation process. The microspheres were characterized in terms of morphology, encapsulation efficiency, and particle size distribution. The effect of different conditions on release property of microspheres was studied.

RESULTThe formed microspheres were spherical with smooth surfaces. The encapsulation efficiency and rate of drug loading were (83.4 +/- 5.63)% and (8.7-0.35)%, respectively. The distribution of particle size was uniform and the average size was (21.5 +/- 1.22) microm. In vitro release study revealed that the 32-hour accumulative release percentage reached 80%.

CONCLUSIONPolylactic acid microspheres containing total alkaloid extracts of C. sinomenii were prepared successfully. Microspheres with good sustained-release characteristics can be produced by controlling different process parameters.

Drugs, Chinese Herbal ; administration & dosage ; chemistry ; Lactic Acid ; chemistry ; Microspheres ; Polyesters ; Polymers ; chemistry ; Sinomenium ; chemistry

BACKGROUNDDrug eluting stents (DESs) made with biodegradable polymer have been developed in an attempt to improve clinical outcomes. However, the impact of biodegradable polymers on clinical events and stent thrombosis (ST) remains controversial.

METHODSWe searched Medline, the Cochrane Library and other internet sources, without language or date restrictions for articles comparing clinical outcomes between biodegradable polymer DES and durable polymer DES. Safety endpoints were ST (definite, definite/probable), mortality, and myocardial infarction (MI). Efficacy endpoints were major adverse cardiac event (MACE) and target lesion revascularization (TLR).

RESULTSWe identified 15 randomized controlled trials (n = 17 068) with a weighted mean follow-up of 20.6 months. There was no statistical difference in the incidence of definite/probable ST between durable polymer- and biodegradable polymer- DES; relative risk (RR) 0.83; 95% confidence interval (CI) 0.62-1.11; P = 0.22. Biodegradable polymer DES had similar rates of definite ST (RR 0.94, 95% CI 0.66-1.33, P = 0.72), mortality (RR 0.94, 95% CI 0.82-1.09, P = 0.43), MI (RR 1.08, 95% CI 0.92-1.26. P = 0.35), MACE (RR 0.99, 95% CI 0.91-1.09, P = 0.85), and TLR (RR, 0.94, 95% CI 0.83-1.06, P = 0.30) compared with durable polymer DES. Based on the stratified analysis of the included trials, the treatment effect on definite ST was different at different follow-up times: ≤ 1 year favoring durable polymer DES and >1 year favoring biodegradable polymer DES.

CONCLUSIONSBiodegradable polymer DES has similar safety and efficacy for treating patients with coronary artery disease compared with durable polymer DES. Further data with longer term follow-up are warranted to confirm the potential benefits of biodegradable polymer DES.

Coronary Artery Disease ; drug therapy ; surgery ; Drug-Eluting Stents ; Humans ; Polymers ; administration & dosage ; Thrombosis

Nanoparticles had received much attention in the development of new kind of pharmaceutical formation because of the special nano-effectivity. Recently, some studies discovered the special functions of the nanoparticles in transdermal and transmucosal drug delivery systems. Even though the acting mechanism of the nanoparticles in these drug delivery systems are not known, these discoveries of the special function of the nanoparticles provide new developing prospect to the drug delivery systems. This paper mainly reviews the present studying results about the nanoparticles used in the transdermal and transmucosal drug delivery systems, including the lipid nanopaticles, natural polymer and the synthesized polymer nanoparticles.
Administration, Cutaneous ; Animals ; Chitosan ; Drug Delivery Systems ; Humans ; Lipids ; Liposomes ; Nanotechnology ; methods ; Polymers

OBJECTIVETo develop a drug delivery system triptolide-polyethylenimine-cyclodextrin and to evaluate its anticancer activity in vitro.

METHODSTriptolide was conjugated to polyethylenimine-cyclodextrin by N, N'-carbonyldiimidazole to form triptolide-polyethylenimine-cyclodextrin. (1)H-NMR, FT-IR and XRD were used to confirm its structure. The anticancer effect of the polymer was assessed by MTT assay, erasion trace test and hematoxylin-eosin staining. The potential to condense siRNA and to delivery siRNA into cytoplasm was demonstrated by gel retardation assay, zeta-potential determination and fluorescence staining.

RESULTSTriptolide was successfully conjugated to polyethylenimine-cyclodextrin and the conjugation rate of triptolide was 10% (w/w). siRNA was effectively condensed by the polymer at the N/P ratio of 5, and its particle size was 300 ±15 nm and zeta potential was 8 ±2.5 mV. MTT assay, erasion trace test and hematoxylin-eosin staining revealed that triptolide-polyethylenimine-cyclodextrin had anticancer effect and low cytotoxicity to normal cells. The polymer was able to deliver siRNA to the cytoplasm effectively as demonstrated by fluorescence staining.

CONCLUSIONTriptolide-polyethylenimine-cyclodextrin is able to inhibit the growth and migration of cancer cells in vitro and to carry siRNA into cells effectively. It is potential to be used as a novel prodrug for co-delivery of gene and drug in cancer treatment.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Cell Line, Tumor ; Cyclodextrins ; Diterpenes ; administration & dosage ; pharmacology ; Drug Carriers ; Epoxy Compounds ; administration & dosage ; pharmacology ; Humans ; Nanoparticles ; Phenanthrenes ; administration & dosage ; pharmacology ; Polyethyleneimine ; Polymers

It has been one of important issues in nanomedicine research field to prepare drug-loaded nanoparticles. Optimization of the preparation parameters plays a key role in obtaining drug-loaded nanoparticles with homogeneous particle size and controlled drug release property. In this paper, gentamicin-loaded PLLA nanoparticles was prepared by means of double emulsion and solvent evaporation technique. Statistical software SPSS was employed to deal with the orthogonal design for optimizing the parameters of the formulation. The in vitro release of gentamicin from nanoparticles was determined by ultra-violet spectroscopy. Analysis of the experimental data based on orthogonal design demonstrated that the concentration of PLLA solution and the molecular weight of PLLA had significant influence on the size of nanoparticles, and the ratio of oil phase to water phase exhibited determined role in the gentamicin release property. Gentamicin-loaded PLLA nanoparticles prepared with the optimized parameters showed homogeneous particle size of 277 nm and sustained release property, which displayed a promising potential of clinical applications.
Delayed-Action Preparations ; chemical synthesis ; Drug Carriers ; Gentamicins ; administration & dosage ; pharmacokinetics ; Lactic Acid ; administration & dosage ; pharmacokinetics ; Nanoparticles ; administration & dosage ; chemistry ; Polyesters ; Polymers ; administration & dosage ; pharmacokinetics

This review presents the most outstanding contribution in the field of polymeric nanoparticles used as targeting drugs delivery systems. Nanoparticles barrier is a novel kind of controlled release system for drugs which can effectively deliver the drug to a target site and increase the bioavailability and therapeutic benefit, while minizing the side effects. In this paper the applications of nanoparticles in the active, passive and physical targeting drugs carriers are reviewed.
Albumins ; administration & dosage ; Antibodies, Monoclonal ; administration & dosage ; Biological Availability ; Cyanoacrylates ; administration & dosage ; Drug Carriers ; Drug Delivery Systems ; Humans ; Nanotechnology ; Particle Size ; Polymers ; administration & dosage

With rapid and efficient drug release, few side effects and excellent biodegradable properties, the reduction-sensitive carriers is not only the new hot point in the field of pharmaceutical research, but also the most promising intelligent drug carrier on clinical application. This paper reviews the latest research of reduction-sensitive drug and gene carriers, including the mechanisms of drug release and the synthesis of the reduction-sensitive conjugates, reduction-sensitive nano polymer micelles, nano vesicles, nano hollow microspheres, nano liposomes, as well as the characteristics and advantages of various kinds of carrier system. It will provide a theoretical basis for its further application.
Drug Carriers ; administration & dosage ; chemistry ; Micelles ; Microspheres ; Nanoparticles ; Oxidation-Reduction ; Pharmaceutical Preparations ; administration & dosage ; chemistry ; Polymers ; chemistry ; Sensitivity and Specificity

In this paper, the advance of polymeric materials applied in the development of traditional Chinese medicine (TCM) and natural products was reviewed. Especially the research progresses in use of the polymeric membranes, polymeric flocculating agents, polymeric sorbents and polymeric drug delivery system (DDS) in the separation and preparation of herb and TCM were discussed in details. In addition, the future develorment of polymeric materials in TCM preparation was also discussed.
Administration, Cutaneous ; Biocompatible Materials ; Drug Delivery Systems ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; Polymers ; Technology, Pharmaceutical ; methods ; Ultrafiltration ; instrumentation

BACKGROUNDFirst generation drug-eluting stents (DESs) were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice.

METHODSCobalt chromium based DES with bioabsorbable polymer (Simrex stent) as well as control stents (Polymer stent and EXCEL(TM) stent) were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography (QCA) analysis, histomorphometry, and electron-microscopical follow-up were performed.

RESULTSA total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis (%DS), late loss (LL), and percent area stenosis (%AS) of Simrex was (12.9 ± 0.4)%, (0.35 ± 0.02) mm, and (24.5 ± 4.2)%, respectively, without significant difference in comparison to commercialized EXCEL(TM) stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4 - 12 weeks for Simrex to complete its re-endothelialization process.

CONCLUSIONSCobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.

Angioplasty, Balloon, Coronary ; Animals ; Chromium Alloys ; administration & dosage ; Coronary Angiography ; Drug-Eluting Stents ; adverse effects ; Polymers ; administration & dosage ; Sirolimus ; administration & dosage ; Swine ; Swine, Miniature