Pluronic modified polyamidoamine (PAMAM) conjugate (PF127-PAMAM) was prepared and the inhibiting effect of MDR against MCF-7/ADR was investigated with doxorubicin (DOX) as model drug. 1H NMR and FTIR spectra showed that the conjugate was synthesized successfully. Element analysis accurately measured that 27.63% amino of per PAMAM was modified by pluronic (PAMAM : PF127, 1 : 35.37 mole ratio). PF127-PAMAM showed an increased size and a reduced zeta potential compared to PAMAM. PF127-PAMAM had lower hemolytic toxicity and cytotoxicity due to the reduced zeta potential and the protection of PF127. Each PF127-PAMAM molecular could load 19.58 DOX molecules, and the complex exhibited sustained and pH-sensitive release behavior. PF127-PAMAM/DOX exhibited weaker cytotoxicity than free DOX in MCF-7 cells; while the complex showed much stronger reverse effect of drug resistance in MCF-7/ADR cells, and resistance reversion index (RRI) was as high as 33.15.
Dendrimers ; pharmacology ; Doxorubicin ; pharmacology ; Humans ; MCF-7 Cells ; drug effects ; Poloxamer ; pharmacology

OBJECTIVETo observe the biodegradation and absorption of poloxamer 407 in vivo, and the effect of poloxamer 407 on the middle ear and inner ear after regional perfusion in guinea pigs.

METHODSThe right ears of 10 guinea pigs as experimental group were perfused with 20% poloxamer 407 in situ gel 100 microl in round window niche, with the left ears as control group with normal saline. Another two animals without treatment were in negative control group. Auditory function was investigated before and 3, 7, 14, 28, 49 days after perfusion, and the histology of bulles after auditory brainstem response (ABR) each examination were examined by means of serial section after paraffin imbedding.

RESULTSThe poloxamer gel was almost biodegraded and discharged 49 days after perfusion, only few gel remained in the middle ear cavity under light microscope. The ABR threshold to filtered clicks was elevated after perfusion with poloxamer 407, and was recovered to normal at 49 days after perfusion. The morphology of the mucosa of middle ear cavity, round window membrane, Corti's and vestibular organs were not significantly damaged after poloxamer 407 perfusion.

CONCLUSIONSPoloxamer 407 can be biodagraded in vivo or discharged via eustachian tube, and causes no inflammation on the middle ear cavity. There are temporary changes on auditory function of inner ear after topical perfusion with poloxamer 407 in round window can cause, but no irreversible damage on function and morphology of cochlear and vestibular organs.

Animals ; Ear, Inner ; drug effects ; Ear, Middle ; drug effects ; Guinea Pigs ; Poloxamer ; administration & dosage ; pharmacology

BACKGROUND: Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water. METHODS: DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation. RESULTS: The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups. CONCLUSIONS: Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.
Animals ; Bone Matrix/*physiology ; Cell Culture Techniques ; Decalcification Technique ; Excipients/*pharmacology ; Hydrogels/pharmacology ; Male ; Mesenchymal Stromal Cells/*drug effects ; Osteogenesis/*drug effects ; Poloxamer/*pharmacology ; Rats ; Rats, Nude

AIMTo explore the intestinal absorption characteristics of lumbrokinase (YJM-I) in the absence or presence of various absorption enhancers and to find the optimum intestinal site for YJM-I absorption.

METHODSThe absorption kinetics and absorption intestinal sites for YJM-I absorption were investigated with the method of diffusion cell in vitro, duodenum bolus injection, recirculating perfusion and in situ duodenum perfusion in vivo.

RESULTSYJM-I could be transported into blood and kept its biological activity across intestinal endothelial membrane after administration via duodenum site, whereas with lower bioavailability. Some of the absorption enhancers were shown good enhancement effects on intestinal absorption of YJM-I in vitro and in situ experiments. The order of enhanced efficiencies of various enhancers on duodenum, ileum and jejunum in vitro permeation experiments were shown as follows: 1% chitosan > 1% SDCh > 1% Na2EDTA > 1% SDS > 1% sodium caprylate > 1% poloxamer > 1% HP-beta-CD. The order of enhanced efficiencies of various enhancers on duodenum absorption of YJM-I in vivo were as follows: 2.5% SDCh > 2.5% Na2EDTA > 2.0% chitosan > 2.5% SDS > 2.5% sodium caprylate > 2.5% Poloxamer > 2.5% HP-beta-CD.

CONCLUSIONThe results indicated that the absorption of YJM-I could be enhanced by various enhancers, and duodenum was the optimum absorption site of YJM-I. Furthermore, bio-adhesive chitosan might be a potential enhancer of intestinal YJM-I absorption.

Administration, Oral ; Animals ; Area Under Curve ; Caprylates ; pharmacology ; Chitosan ; pharmacology ; Deoxycholic Acid ; pharmacology ; Duodenum ; drug effects ; metabolism ; Edetic Acid ; pharmacology ; Endopeptidases ; administration & dosage ; pharmacokinetics ; Injections, Intravenous ; Intestinal Absorption ; Male ; Metabolic Clearance Rate ; Poloxamer ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore Poloxamer 188, a non-ionic surfactant as a potential tool for early intervention into the chondrocyte damaged by blunt mechanical trauma in vitro.

METHODSThree groups were control group (n = 6), no treatment group (n = 12) and Poloxamer 188 treatment group (n = 12). Two groups are then loaded to 20 MPa in unconfined compression. At 1 and 24 h the percentages of live and dead cells of superficial zone in compressed and control groups were determined with a cell viability stain.

RESULTSAt 1 h post-trauma, specimens of Poloxamer 188 treatment group (76%) had a significantly increased percentage of live cells in the superficial zone versus the no treatment group (55%). In 24 h the percentages of live cells in the superficial zone of the Poloxamer 188 treatment group (57%) were significantly greater than in the no treatment group (38%).

CONCLUSIONSPoloxamer 188 surfactant could help restore the integrity of cell membranes in cartilage damaged by blunt mechanical trauma. Models of mechanical cartilage injury in vitro may explain aspect of the interactions between mechanical forces and degradative pathways which lead to osteoarthritis progression.

Apoptosis ; drug effects ; Cartilage, Articular ; pathology ; Cell Survival ; drug effects ; Chondrocytes ; drug effects ; pathology ; Humans ; In Vitro Techniques ; Poloxamer ; pharmacology ; Random Allocation ; Weight-Bearing

To investigate the inhibitory effect of Pluronic on P-glycoprotein (P-gp) drug efflux pump, Caco-2 cells and animal models were established to study the influence of Pluronic on celiprolol transport across Caco-2 cell monolayer and intestinal mucous membrane with verapamil set as a positive control. Drug concentration was measured by HPLC and the apparent permeability coefficient (P(app)), absorption rate constant (k(a)) and the effective permeability coefficient (P(eff)) were calculated. P(app) of basolateral to apical side and apical to basolateral side was (2.10 +/- 0.13) x 10(-6) and (0.333 +/- 0.018) x 10(-6) cm x s(-1), respectively. Transports of celiprolol across Caco-2 cell monolayer were influenced by both verapamil and Pluronic. The absorption constants (k(a)) of celiprolol at duodenum, jejunum, ileum, and colon were (0.09 +/- 0.03), (0.14 +/- 0.04), (0.11 +/- 0.03) and (0.05 +/- 0.02) h(-1), k(a) of celiprolol in verapamil group were (0.14 +/- 0.03), (0.24 +/- 0.02), (0.25 +/- 0.03) and (0.23 +/- 0.02) h(-1), and k(a) of celiprolol in Pluronic group were (0.13 +/- 0.02), (0.22 +/- 0.02), (0.22 +/- 0.03) and (0.20 +/- 0.03) h(-1), respectively. Pluronic showed significant effect on inhibiting P-gp of Caco-2 cell and intestinal mucosa in rats.
ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Animals ; Biological Transport ; drug effects ; Caco-2 Cells ; Celiprolol ; pharmacokinetics ; Excipients ; Humans ; Intestinal Absorption ; drug effects ; Intestinal Mucosa ; metabolism ; Jejunum ; metabolism ; Male ; Permeability ; Poloxamer ; administration & dosage ; pharmacology ; Rats ; Rats, Sprague-Dawley

Gabexate mesilate (GM) is a trypsin inhibitor, and mainly used for treatment of various acute pancreatitis, including traumatic pancreatitis (TP), edematous pancreatitis, and acute necrotizing pancreatitis. However, due to the characteristics of pharmacokinetics, the clinical application of GM still needs frequently intravenous administration to keep the blood drug concentration, which is difficult to manage. Specially, when the blood supply of pancreas is directly damaged, intravenous administration is difficult to exert the optimum therapy effect. To address it, a novel thermosensitive in-situ gel of gabexate mesilate (GMTI) was developed, and the optimum formulation of GMTI containing 20.6% (w/w) P-407 and 5.79% (w/w) P188 with different concentrations of GM was used as a gelling solvent. The effective drug concentration on trypsin inhibition was examined after treatment with different concentrations of GMTI in vitro, and GM served as a positive control. The security of GMTI was evaluated by hematoxylin-eosin (HE) staining, and its curative effect on grade II pancreas injury was also evaluated by testing amylase (AMS), C-reactive protein (CRP) and trypsinogen activation peptide (TAP), and pathological analysis of the pancreas. The trypsin activity was slightly inhibited at 1.0 and 5.0 mg/mL in GM group and GMTI group, respectively (P<0.05 vs. P-407), and completely inhibited at 10.0 and 20.0 mg/mL (P<0.01 vs. P-407). After local injection of 10 mg/mL GMTI to rat leg muscular tissue, muscle fiber texture was normal, and there were no obvious red blood cells and infiltration of inflammatory cells. Furthermore, the expression of AMS, CRP and TAP was significantly increased in TP group as compared with control group (P<0.01), and significantly decreased in GM group as compared with TP group (P<0.01), and also slightly inhibited after 1.0 and 5.0 mg/mL GMTI treatment as compared with TP group (P<0.05), and significantly inhibited after 10.0 and 20.0 mg/mL GMTI treatment as compared with TP group (P<0.01). HE staining results demonstrated that pancreas cells were uniformly distributed in control group, and they were loosely arranged, partially dissolved, with deeply stained nuclei in TP group. Expectedly, after gradient GMTI treatment, pancreas cells were gradually restored to tight distribution, with slightly stained nuclei. This preliminary study indicated that GMTI could effectively inhibit pancreatic enzymes, and alleviate the severity of trauma-induced pancreatitis, and had a potential drug developing and clinic application value.
Amylases ; metabolism ; Animals ; C-Reactive Protein ; metabolism ; Delayed-Action Preparations ; chemical synthesis ; pharmacokinetics ; pharmacology ; Gabexate ; chemistry ; pharmacokinetics ; pharmacology ; Gels ; Male ; Muscle, Skeletal ; drug effects ; enzymology ; Oligopeptides ; metabolism ; Pancreas ; drug effects ; enzymology ; pathology ; Pancreatitis ; drug therapy ; enzymology ; etiology ; pathology ; Poloxamer ; chemistry ; Rats ; Rats, Sprague-Dawley ; Serine Proteinase Inhibitors ; chemistry ; pharmacokinetics ; pharmacology ; Temperature ; Wounds, Penetrating ; complications ; drug therapy ; enzymology ; pathology

The aim of this study is to establish a simple and stable model like poloxamer 407 (P-407)-induced dyslipidemia of golden hamster model, and investigate the mechanism of lipid metabolism disturbance in this model. PPARalpha agonist and HMG-CoA reductase inhibitor were administrated to validate the efficacy on regulating lipid metabolism in the dyslipidemia golden hamster model. Six weeks male golden hamsters were chosen to inject P-407 intraperitoneally at a bolus dose of 300 mg x kg(-1), an intermittent injection at a dose of 200 mg x kg(-1) every 72 hours after the bolus. The results showed that P-407-induced golden hamster model characterized as increased serum triglyceride (TG), total cholesterol (TC), free cholesterol (free-CHO), cholesteryl ester (CE), free fatty acids (FFA) and apoB levels, and the hyperlipidemia state maintained at a stable level persistently. Meanwhile, augmented malondialdehyde (MDA) and nitric oxide (NO) level was observed. LCAT and SR-B I mRNA levels in liver of model group were down-regulated (expression ratio is 0.426; 0.783), while HMG-CoA reductase mRNA level was up-regulated (expression ratio is 1.493) compared with those of the normal group. The serum cholesterol and triglyceride levels were significantly lower in P-407-induced dyslipidemia hamster model after treated with atorvastatin (Ato) at a dose of 50 mg x kg(1) or fenofibrate (Fen) at 100 mg x kg(-1) for two weeks. These findings suggest that serum lipid distribution in dyslipidemia golden hamster is similar to that of human, and which may be relevant to the disturbance of the enzymes expression involved in lipid metabolism in liver. Results obtained from this study support the concept that dyslipidemia golden hamster may be an adequate animal model to evaluate the efficacy of lipid-lowering agents.
Animals ; Anticholesteremic Agents ; pharmacology ; Atorvastatin Calcium ; CD36 Antigens ; genetics ; metabolism ; Cricetinae ; Disease Models, Animal ; Dyslipidemias ; chemically induced ; metabolism ; Fenofibrate ; pharmacology ; Heptanoic Acids ; pharmacology ; Hydroxymethylglutaryl CoA Reductases ; genetics ; metabolism ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Hypolipidemic Agents ; pharmacology ; Lipid Metabolism ; Liver ; metabolism ; Male ; Malondialdehyde ; metabolism ; Mesocricetus ; Nitric Oxide ; metabolism ; PPAR alpha ; agonists ; Phosphatidylcholine-Sterol O-Acyltransferase ; genetics ; metabolism ; Poloxamer ; Pyrroles ; pharmacology ; RNA, Messenger ; metabolism ; Superoxide Dismutase ; metabolism

To prepare polyrotaxane-camptothecin conjugates and evaluate its anti-tumor effect, polyrotaxane-camptothecin conjugates were successfully synthesized, and the release behavior was performed; MTT assay and cell morphology were used to examine the inhibition of cells' proliferation effect in vitro. The experimental study of the antitumor effect on S180 mice in vivo was also performed to further evaluate the anti-tumor effect of conjugate. The result showed polyrotaxane-camptothecin conjugates can effectively inhibit the proliferation in a dose dependent effect. In vivo study and cell morphology observation of S180 mice showed significant decrease in growth of tumor, degree of tumor infiltration and blood vessel number. The result indicated anti-tumor mechanism may be through affect the angiogenesis and reduced blood supply to tumor cells and then leading to necrosis.
Animals ; Antineoplastic Agents, Phytogenic ; administration & dosage ; pharmacology ; Camptothecin ; administration & dosage ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclodextrins ; chemistry ; Drug Carriers ; Drug Compounding ; Female ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Ovarian Neoplasms ; pathology ; Poloxamer ; chemistry ; Rotaxanes ; chemistry ; Sarcoma 180 ; pathology ; Tumor Burden ; drug effects

Drug delivery system (DDS) is a novel approach to overcome multidrug resistance (MDR) in tumors nowadays. This work was designed to investigate a new micellar delivery system for in vitro reversal of resistant ovarian tumor cells, based on a nonionic triblock copolymer Pluronic P105 and paclitaxel (PTX). The PTX-loaded polymeric micelles (P105/PTX) were prepared by thin film-hydration methods. Based on the results of single factor experiments, the P105/PTX micelle formulation was optimized by employing the central composite design-response surface methodology. The physico-chemical properties of the P105/PTX micelles were characterized, including micelle size, drug loading coefficient, in vitro release behavior, etc. The cytotoxicity of the P105/PTX micelles was assessed against human ovarian tumor cell line, SKOV-3/PTX, by a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. In order to understand the possible mechanism of Pluronic effects in resistant tumor cells, cellular uptake study of micellar PTX or Rhodamine-123 (R-123) was also carried out. The results showed that the micelle size was about 24 nm with drug loading coefficient of 1.1% and PTX concentration of 700 microg x mL(-1). The cumulative release amount of PTX from the P105/PTX micelles was only 45.4% in 6 h (P < 0.05) and 79.6% in 24 h, whereas Taxol injection in 6 h released 95.2% PTX. The IC50 values of the P105/PTX micelles and Taxol injection against SKOV-3/PTX were 1.14 and 5.11 microg x mL(-1), and resistance reversion index (RRI) was 9.65 and 2.15, respectively. The micellar PTX or R-123 exhibited a significant increase in cellular uptake in resistant SKOV-3/PTX cells compared with free PTX or R-123. These results indicated that PTX could effectively be solubilized by Pluronic P105 block copolymers via thin film-hydration process and formulation optimization, producing nano-scale polymeric micelles with sustained release property in vitro. The P105/PTX micelles were effectively able to reverse resistance to PTX in SKOV-3/PTX tumor cells compared with Taxol injection or free PTX solution, and the enhanced cytotoxicity in the resistant SKOV-3/PTX cell was related to the improved cellular uptake of PTX by Pluronic P105 copolymers.
Antineoplastic Agents, Phytogenic ; administration & dosage ; chemistry ; pharmacology ; Cell Line, Tumor ; Drug Carriers ; Drug Delivery Systems ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Excipients ; chemistry ; Female ; Humans ; Inhibitory Concentration 50 ; Micelles ; Ovarian Neoplasms ; metabolism ; pathology ; Paclitaxel ; administration & dosage ; chemistry ; metabolism ; pharmacology ; Particle Size ; Poloxamer ; chemistry