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1.
A series of novel amphiphilic triblock copolymers of poly(ethyl ethylene phosphate) and poly(-caprolactone) (PEEP-PCL-PEEP) with various PEEP and PCL block lengths were synthesized and characterized. These triblock copolymers formed micelles composed of a hydrophobic core of poly(-caprolactone) (PCL) and a hydrophilic shell of poly(ethyl ethylene phosphate) (PEEP) in aqueous solution. The micelle morphology was spherical, determined by transmission electron microscopy. It was found that the size and critical micelle concentration values of the micelles depended on both hydrophobic PCL block length and PEEP hydrophilic block length. The in vitro degradation characteristics of the triblock copolymers were investigated in micellar form, showing that these copolymers were completely biodegradable under enzymatic catalysis of Pseudomonas lipase and phosphodiesterase I. These triblock copolymers were used for paclitaxel (PTX) encapsulation to demonstrate the potential in drug delivery. PTX was successfully loaded into the micelles, and the in vitro release profile was found to be correlative to the polymer composition. These biodegradable triblock copolymer micelles are potential as novel carriers for hydrophobic drug delivery. 相似文献
2.
Formation of core-shell type biodegradable polymeric micelles from amphiphilic poly(aspartic acid)-block-polylactide diblock copolymer 总被引:1,自引:0,他引:1
Poly(aspartic acid)-block-polylactide diblock copolymers (PAsp-b-PLAs) having both hydrophilic and hydrophobic segments of various lengths were synthesized. These PAsp-b-PLA diblock copolymers formed polymeric micelles consisting of a hydrophobic PLA core and a hydrophilic, pH-sensitive PAsp shell in aqueous solution. The effects of the segment length of both the PLA and the PAsp portions and the pH of the solution on the shapes and sizes of the PAsp-b-PLA polymeric micelles were investigated. The results indicated a balance between the effects of electrostatic repulsion, hydrogen bonding in the PAsp shell layer, and hydrophobic interactions in the PLA core determine the sizes of the PAsp-b-PLA polymeric micelles. Moreover, the PAsp-b-PLA polymeric micelles did not possess any cytotoxic activity against L929 fibroblast cells. The obtained polymeric micelle should be useful for biodegradable biomedical materials such as drug delivery vehicle. 相似文献
3.
M. H. Sawyer P. Baumann L. Baumann S. M. Berman J. L. Cánovas R. H. Berman 《Archives of microbiology》1977,112(1):49-55
Cell-free extracts of d-fructose grown cells of Pseudomonas putida, P. fluorescens, P. aeruginosa, P. stutzeri, P. mendocina, P. acidovorans and P. maltophila catalyzed a P-enolpyruvate-dependent phosphorylation of d-fructose and contained 1-P-fructokinase activity suggesting that in these species fructuse-1-P and fructose-1,6-P2 were intermediates of d-fructose catabolism. Neither the 1-P-fructokinase nor the activity catalyzing a P-enolpyruvate-dependent phosphorylation of d-fructose was present in significant amounts in succinate-grown cells indicating that both activities were inducible. Cell-free extracts also contained activities of fructose-1,6-P2 aldolase, fructose-1,6-P2 phosphatase, and P-hexose isomerase which could convert fructose-1,6-P2 to intermediates of either the Embden-Meyerhof pathway or Entner-Doudoroff pathway. Radiolabeling experiments with 1-14C-d-fructose suggested that in P. putida, P. aeruginosa, P. stutzeri, and P. acidovorans most of the alanine was made via the Entner-Doudoroff pathway with a minor portion being made via the Embden-meyerhof pathway. An edd
- mutant of P. putida which lacked a functional Entner-Doudoroff pathway but was able to grow on d-fructose appeared to make alanine solely via the Embden-Meyerhof pathway.Non-Standard Abbreviations cpm
counts per min
-
edd
-
mutant lacking Entner-Doudoroff dehydrase (6-PGA dehydrase)
- EDP
Entner-Doudoroff pathway
- EMP
Embden-Meyerhof pathway
- FDP
fructose-1,6-P2
- FDPase
FDP phosphatase
- F-1-P
fructose-1-P
- F-6-P
fructose-6-P
- FPTs
PEP: d-fructose phosphotransferase system
- G-6-P
glucose-6-P
- KDPG
2-keto-3-deoxy-6-P-gluconate
- PEP
P-enolpyruvate
- 1-PFK
1-P-fructokinase
- 6-PFK
6-P-fructokinase
- 6-PGA
6-P-gluconate 相似文献
4.
Ji Zheng S. Robert Northrup Peter J. Hornsby 《In vitro cellular & developmental biology. Animal》1998,34(9):679-684
Summary We describe a method for increasing the hydrophilicity of materials formed from biodegradable polymers and introducing chemical
functional groups on their surfaces. Poly(L-lactic acid) was blended with poly(ɛ-CBZ-L-lysine) at an 80:20 ratio. Films of the mixture were prepared and foams were made by solvent casting and salt leaching. Amino
groups on the surface of the polymer mixture were deprotected by acid hydrolysis. As an example of the applicability of the
technique for attachment of biomolecules, we covalently linked collagen to the deprotected amino groups, creating a surface
capable of high density growth of a differentiated cell type (bovine adrenocortical cells). The method should be generally
useful for surface modification of biodegradable polymer materials used in tissue engineering. 相似文献
5.
Amphiphilic diblock copolymers with varying compositions of hydrophilic poly(ethylene oxide) (PEO) and hydrophobic poly[bis(ethyl glycinat-N-yl)phosphazene] (PNgly) were synthesized via the controlled cationic-induced polymerization of a phosphoranimine (Cl(3)P=NSiMe(3)) at ambient temperature using a PEO-phosphoranimine macroinitiator. The aqueous-phase transition behavior of PEO-PNgly-3 (M(n) = 10,000) and micelle formation of both PEO-PNgly-3 and PEO-PNgly-4 (M(n) = 8,500) were investigated using fluorescence techniques and dynamic light scattering. The critical micelle concentrations (cmc's) of PEO-PNgly-3 and PEO-PNgly-4 were determined to be 3 and 12 mg/L with the mean diameters of micelles being 120 and 130 nm, respectively. The hydrolytic degradation of these diblock copolymers was also studied in solution. These studies coupled with the biodegradability of the poly[bis(ethyl glycinat-N-yl)phosphazene] block to give benign products make PEO-PNgly copolymers well-suited for a wide variety of biomedical applications including novel biodegradable drug-delivery systems. 相似文献
6.
Cell-free extracts of d-fructose grown cells of marine species of Alcaligenes as well as Pseudomonas marina contained an activity which catalyzed a P-enolpyruvate-dependent phosphorylation of d-fructose in the 1-position as well as activities of the following enzymes: 1-P-fructokinase, fructose-1,6-P2 aldolase, PPi-dependent 6-P-fructokinase, fructokinase, glucokinase, P-hexose isomerase, glucose-6-P dehydrogenase, 6-P-gluconate dehydrase, and 2-keto-3-deoxy-6-P-gluconate aldolase. The presence of these enzyme activities would allow d-fructose to be degraded by the Embden-Meyerhof pathway and/or the Entner-Doudoroff pathway. In cell-free extracts of d-glucose grown cells, the activity catalyzing a P-enolpyruvate-dependent phosphorylation of d-fructose as well as 1-P-fructokinase activity were reduced or absent while the remaining enzymes were present at levels similar to those found in d-fructose grown cells. Radiolabeling experiments suggested that both d-fructose and d-glucose were utilized primarily via the Entner-Doudoroff pathway. Alteromonas communis, a marine species lacking 1-P-fructokinase and the PPi-dependent 6-P-fructokinase, contained all the enzyme activities necessary for the catabolism of d-fructose and d-glucose by the Entner-Doudoroff pathway; the involvement of this pathway was also consistent with the results of the radiolabeling experiments.Non-Standard Abbreviations EDP
Entner-Doudoroff pathway
- EMP
Embden-Meyerhof pathway
- FDP
fructose-1,6-P2
- FDPase
FDP phosphatase
- F-1-P
fructose-1-P
- F-6-P
fructose-6-P
- FPTS
PEP: d-fructose phosphotransferase system
- PPi-6-PFK
PPi dependent 6-PFK
- G-6-P
glucose-6-P
- KDPG
2-keto-3-deoxy-6-P-gluconate
- PEP
P-enolpyruvate
- 1-PFK
1-P-fructokinase
- 6-PFK
6-P-fructokinase
- 6-PGA
6-P-gluconate 相似文献
7.
Cross-linkable di- and triblock copolymers of poly(epsilon-caprolactone) (PCL) and monomethoxyl poly(ethylene glycol) (MPEG) were synthesized. These amphiphilic copolymers self-assembled into nanoscale micelles capable of encapsulating hydrophobic paclitaxel in their hydrophobic cores in aqueous solutions. To further enhance their thermodynamic stability, the micelles were cross-linked by radical polymerization of the double bonds introduced into the PCL blocks. Reaction conditions were found to significantly affect both the cross-linking efficiency and the micelle size. The encapsulation of paclitaxel into the micelles was confirmed by the proton nuclear magnetic resonance (1H NMR) spectroscopy. Encouragingly, paclitaxel-loading efficiency of micelles was enhanced significantly upon micelle core-cross-linking. Both the micelle size and the drug loading efficiency increased markedly with increasing the PCL block lengths, no matter if the micelles were core-cross-linked or not. However, paclitaxel-loading did not obviously affect the micelle size or size distribution. The cross-linked micelles exhibited a significantly enhanced thermodynamic stability against dilution with aqueous solvents. The efficient cellular uptake of paclitaxel loaded in the nanomicelles was demonstrated by confocal laser scanning microscopy (CLSM) imaging. This new biodegradable nanoscale carrier system merits further investigations for parenteral drug delivery. 相似文献
8.
A novel biodegradable amphiphilic brush-coil block copolymer consisting of poly(epsilon-caprolactone) and PEGylated polyphosphoester was synthesized by ring opening polymerization. The composition and structure of the copolymer were characterized by 1H NMR, 13C NMR, and FT-IR, and the molecular weight and molecular weight distribution were analyzed by gel permeation chromatograph (GPC) measurements to confirm the diblock structure. These amphiphilic copolymers formed micellar structures in water, and the critical micelle concentrations (CMCs) were around 10(-3) mg/mL, which was determined using pyrene as a fluorescence probe. Transmission electron microscopy (TEM) images showed that the micelles took an approximately spherical shape with core-shell structure, which was further demonstrated by laser light scattering (LLS) technique. The degradation behavior of the polymeric micelle was also investigated in the presence of Pseudomonas lipase and characterized by GPC measurement. Such polymer micelles from brush-coil block copolymers are expected to have wide utility in the field of drug delivery. 相似文献
9.
Syntheses of l-dopa 1a glucoside 10a,b and dl-dopa 1b glycosides 10–18 with d-glucose 2, d-galactose 3, d-mannose 4, d-fructose 5, d-arabinose 6, lactose 7, d-sorbitol 8 and d-mannitol 9 were carried out using amyloglucosidase from Rhizopus mold, β-glucosidase isolated from sweet almond and immobilized β-glucosidase. Invariably, l-dopa and dl-dopa gave low to good yields of glycosides 10–18 at 12–49% range and only mono glycosylated products were detected through glycosylation/arylation at the third or fourth
OH positions of l-dopa 1a and dl-dopa 1b. Amyloglucosidase showed selectivity with d-mannose 4 to give 4-O-C1β and d-sorbitol 8 to give 4-O-C6-O-arylated product. β-Glucosidase exhibited selectivity with d-mannose 4 to give 4-O-C1β and lactose 7 to give 4-O-C1β product. Immobilized β-glucosidase did not show any selectivity. Antioxidant and angiotensin converting enzyme inhibition
(ACE) activities of the glycosides were evaluated glycosides, out of which l-3-hydroxy-4-O-(β-d-galactopyranosyl-(1′→4)β-d-glucopyranosyl) phenylalanine 16 at 0.9 ± 0.05 mM and dl-3-hydroxy-4-O-(β-d-glucopyranosyl) phenylalanine 11b,c at 0.98 ± 0.05 mM showed the best IC50 values for antioxidant activity and dl-3-hydroxy-4-O-(6-d-sorbitol)phenylalanine 17 at 0.56 ± 0.03 mM, l-dopa-d-glucoside 10a,b at 1.1 ± 0.06 mM and dl-3-hydroxy-4-O-(d-glucopyranosyl)phenylalanine 11a-d at 1.2 ± 0.06 mM exhibited the best IC50 values for ACE inhibition.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Ai H Lvov YM Mills DK Jennings M Alexander JS Jones SA 《Cell biochemistry and biophysics》2003,38(2):103-114
A recently developed method for surface modification, layer-by-layer (LbL) assembly, has been applied to silicone, and its
ability to encourage endothelial cell growth and control cell growth patterns has been examined. The surfaces studied consisted
of a precursor, with alternating cationic polyethyleneimine (PEI) and anionic sodium polystyrene sulfonate (PSS) layers followed
by alternating gelatin and poly-d-lysine (PDL) layers. Film growth increased linearly with the number of layers. Each PSS/PEI bilayer was 3 nm thick, and each
gelatin/PDL bilayer was 5 nm thick. All layers were more hydrophilic than the unmodified silicone rubber surface, as determined
from contact angle measurements. The contact angle was primarily dictated by the outermost layer. Of the coatings studied,
gelatin was the most hydrophilic. A film of (PSS/PEI)4/(gelatin/PDL)4/ gelatin was highly favorable for cell adhesion and growth, in contrast to films of (PSS/PEI)8 or (PSS/PEI)8/PSS. Cell growth patterns were successfully controlled by selective deposition of microspheres on silicone rubber, using
microcontact printing with a silicone stamp. Cell adhesion was confined to the region of microsphere deposition. These results
demonstrate that the LbL self-assembly technique provides a general approach to coat and selectively deposit films with nanometer
thickness on silicone rubber. Furthermore, they show that this method is a viable technique for controlling cellular adhesion
and growth. 相似文献
11.
The lead ion-catalyzed oligomerization of 5′-phosphorimidazolides of D-, L- or racemic DL-adenosine (D-ImpA, L-ImpA and DL-ImpA) gave oligoadenylates up to a pentamer. The oligomers resulting from racemic ImpA were comparable in yields and length
to those from chiral D- or L-ImpA. A complex mixture of homochiral and heterochiral oligomers was formed in the reaction from racemic ImpA. Total dimer
product from racemic ImpA by the lead ion catalyst showed homochiral selectivity. The reaction catalyzed by uranyl ion yielded
oligoadenylates up to 15mer from chiral D- or L-ImpA in over 95% yield. A complex mixture of isomeric oligoadenylates was formed from racemic DL-ImpA in the presence of uranyl ion catalyst in comparable yields to those from D- or L-ImpA. The analysis of the dimer product from DL-ImpA showed that the homochiral 2′ –5′ linked dimer was selectively formed. D-ImpA polymerized effectively on a poly(U) template, which is exclusively composed of D-uridine, yielding oligoadenylates up to a pentamer. In contrast, L-ImpA or racemic DL-ImpA polymerized far less efficiently on the poly(U) template, demonstrating that chiral selection takes place in the poly(U)
template-directed oligoadenylate formation. 相似文献
12.
The aim of the investigation was to prepare and characterize wheat germ agglutinin(WGA)-conjugated poly(d,l-lactic-co-glycolic) acid nanoparticles encapsulating mometasone furoate (MF) as a model drug and assess changes in its fate in terms
of cellular interactions. MF loaded nanoparticles were prepared using emulsion–solvent evaporation technique. WGA-conjugation
was done by carbodiimide coupling method. The nanoparticles were characterized for size, zeta potential, entrapment efficiency
and in-vitro drug release. The intracellular uptake of nanoparticles, drug cellular levels, and anti-proliferative activity studies of
wheat germ agglutinin-conjugated and unconjugated nanoparticles were assessed on alveolar epithelial (A549) cells to establish
cellular interactions. Prepared nanoparticles were spherical with 10–15 μg/mg of WGA conjugated on nanoparticles. The size
of nanoparticles increased after conjugation and drug entrapment and zeta potential reduced from 78 ± 5.5% to 60 ± 2.5% and
−15.3 ± 1.9 to −2.59 ± 2.1 mV respectively after conjugation. From the cellular drug concentration–time plot, AUC was found
to be 0.4745, 0.6791 and 1.24 for MF, MF-nanoparticles and wheat germ agglutinin-MF-nanoparticles respectively. The in-vitro antiproliferative activity was improved and prolonged significantly after wheat germ agglutinin-conjugation. The results
conclusively demonstrate improved availability and efficacy of antiasthmatic drug in alveolar epithelial cell lines. Hence,
a drug once formulated as mucoadhesive nanoparticles and incorporated in dry powder inhaler formulation may be used for targeting
any segment of lungs for more improved therapeutic response in other lung disorders as well. 相似文献
13.
The goal of this study was to develop a new type of core-shell micelles based on biocompatible and biodegradable amphiphilic copolymers, named PCL-CS, using chondroitin sulfate (CS) as a hydrophilic segment and poly(epsilon-caprolactone) (PCL) as a hydrophobic segment. The copolymers, prepared from the various compositions between CS and PCL, were characterized by Fourier transform infrared spectrometer, proton nuclear magnetic resonance spectrometer, and differential scanning calorimeter. The PCL-CS copolymers could be assembled into micelles using a simple emulsion. With the fluorescent probe technique, the critical micelle concentrations were obtained in the range of 1.26 x 10(-3)-8.86 x 10(-3) mg/mL. The spherical images of micelles were visualized in the presence of polyvinyl alcohol (PVA) with the use of the transmission electron microscope. The particle sizes of micelles were all smaller than 300 nm, neither aggregate nor change in hydrodynamic sizes after 15 days staying in solutions containing salts or PVA by dynamic light scattering. The intracellular uptake of KB cells incubated with PCL-CS micelles was evidenced by confocal laser scanning microscope upon loading fluorescein isothiocyanate labeled bovine serum albumin as a probe. 相似文献
14.
van Sandick JW Boermeester MA Gisbertz SS ten Berge IJ Out TA van der Pouw Kraan TC van Lanschot JJ 《Cancer immunology, immunotherapy : CII》2003,52(10):617-624
Introduction Recent studies have indicated that the cytokines produced by CD4+ T helper type 1 (Th1) and type 2 (Th2) cells are critically important in antitumour immunity and perhaps clinical outcome. From this perspective, we investigated the immunocompetence of patients with previously untreated cancer of the oesophagus or oesophagogastric junction (OGJ) in relation to stage of disease and postoperative survival.Methods Blood samples were taken prior to surgery from 32 patients with adenocarcinoma of the oesophagus or OGJ. Ten healthy volunteers served as normal controls. T-cell and monocyte subpopulations were determined using flow cytometry. Monocyte as well as Th1- and Th2-lymphocyte cytokine levels were assessed in stimulated whole blood cultures.Results Absolute T-cell and monocyte (subset) counts as well as monocyte cytokine levels were similar among patients and controls. Production of Th1-type cytokines was higher in patients than in controls (IFN-, p=0.01; IL-2, p=0.05), whereas Th2-type cytokine levels were comparable (IL-4, p=0.5; IL-13, p=0.3). T-cell CD4+/CD8+ ratios decreased as pTNM stage worsened (stage I/II vs stage III/IV, p=0.009). Of all measured immunological parameters, only IL-2 production significantly affected both overall survival (p=0.015) and disease-free survival (p=0.0062). High IL-2 levels corresponded with a favourable prognosis.Conclusions Patients awaiting surgery for adenocarcinoma of the oesophagus or oesophagogastric junction demonstrated a shift in the Th1/Th2 balance—in favour of Th1—compared with healthy volunteers. The ability of T cells to produce IL-2 was related to survival indicating a crucial role of Th1-type cells in antitumour immunosurveillance. 相似文献
15.
This study focuses on the aggregation behavior of the biodegradable amphiphilic block copolymers based on methoxy poly(ethylene glycol) (mPEG) as a hydrophilic block and either crystalline poly(caprolactone-b-l-lactide) (P(CL-LLA)) or amorphous poly(caprolactone-b-D,L-lactide) (P(CL-DLLA)) as a hydrophobic block. These block copolymers have a strong tendency to form micelles in aqueous medium, with very low critical micelle concentrations (CMCs). The CMC of P(CL-LLA)-b-mPEG is higher than that of P(CL-DLLA)-b-mPEG when the mPEG block has the same molecular weight. Furthermore, the partition equilibrium coefficient (K(v)) of pyrene in the micellar solution of P(CL-LLA)-b-mPEG copolymer was lower than that of P(CL-DLLA)-b-mPEG copolymer when the mPEG block was the same length. These differences were believed to be related to the physical state of the core-forming blocks, i.e., the crystalline P(CL-LLA) block and the amorphous P(CL-DLLA) block. The TEM images showed that micelles formed by P(CL-LLA)-b-mPEG assembled in a cylindrical morphology, whereas those formed by P(CL-DLLA)-b-mPEG took a classical spherical shape. In addition, with differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) analyses, it is believed that the crystallization tendency of the core-forming blocks is the main factor governing the morphology of micelles in water. A possible mechanism for the cylindrical assembly morphology was discussed. 相似文献
16.
The thermophilic phototrophic prokaryote, Chloroflexus aurantiacus was shown to contain high constitutive l-threonine (l-serine) deaminating activity. Separation of cellular proteins by DE 52-cellulose chromatography and by polyacrylamide gel electrophoresis with subsequent activity staining of the gels yielded two bands, one representing an isoleucine-sensitive, the other one an isoleucine-insensitive form of l-threonine dehydratase. Both enzymes had a molecular weight of 120,000 but were distinguished by their different affinities to the two substrates, l-threonine and l-serine.Abbreviations SDH
l-serine dehydratase
- TDH
l-threonine dehydratase 相似文献
17.
Clostridium sphenoides was grown on glucose in a phosphate-limited medium. Below 80 M phosphate two new products were formed in addition to ethanol, acetate, H2 and CO2: d(-)-1,2-propanediol and d(-)-lactate. These compounds were apparently synthesized via the methylglyoxal by-pass. The activity of the enzymes involvedmethylglyoxal synthase, methylglyoxal reductase, 1,2-propanediol dehydrogenase and glyoxalase-could be demonstrated in cell extracts of C. sphenoides. The formation of 1,2-propanediol from methylglyoxal proceeded via lactaldehyde. The enzyme methylgloxal synthase was inhibited by phosphate.
Clostridium glycolicum, C. nexile, C. cellobioparum, C. oroticum and C. indolis did not produce propanediol under the condition of phosphate limitation. The latter two species, however, formed d(-)-lactate.Dedicated to Prof. Dr. G. Drews on the occasion of his 60th birthday 相似文献
18.
Ricardo Titze-de-Almeida Cilene Lino de Oliveira Hilda W. Shida Francisco Silveira Guimarães Elaine Aparecida Del Bel 《Cellular and molecular neurobiology》1994,14(4):373-380
Summary 1. The effects of restraint stress on c-fos mRNA expression in the dentate gyrus were investigated byin situ hybridization.2. Confirming previous findings, c-fos mRNA expression increased after 30 min of forced restraint.3. This effect was attenuated by a previous i.c.v. injection of the anxiolytic benzodiazepine midazolam (20 nmol/2 µl) or theN-methyl-d-aspartate (NMDA) receptor antagonist 2-amino-7-phosphonoheptanoic acid (AP-7; 5 nmol/2 µl).4. These results suggest that the dentate gyrus is activated during restraint stress and that this activation may be modulated by benzodiazepine -aminobutyric acidA (GABAA) or NMDA receptors. 相似文献
19.
Six amphiphilic diblock copolymers based on methoxy poly(ethylene glycol) (MePEG) and poly(delta-valerolactone) (PVL) with varying hydrophilic and hydrophobic block lengths were synthesized via a metal-free cationic polymerization method. MePEG-b-PVL copolymers were synthesized using MePEG with Mn = 2000 or Mn = 5000 as the macroinitiator. 1H NMR and GPC analyses confirmed the synthesis of diblock copolymers with relatively narrow molecular weight distributions (Mn/Mw = 1.05-1.14). DSC analysis revealed that the melting temperatures (Tm) of the copolymers (47-58 degrees C) approach the Tm of MePEG as the PVL content is decreased. MePEG-b-PVL copolymer aggregates loaded with the hydrophobic anti-cancer drug paclitaxel were found to have effective mean diameters ranging from 31 to 970 nm depending on the composition of the copolymers. A MePEG-b-PVL copolymer of a specific composition was found to form drug-loaded micelles of 31 nm in diameter with a narrow size distribution and improve the apparent aqueous solubility of paclitaxel by more than 9000-fold. The biological activity of paclitaxel formulated in the MePEG-b-PVL micelles was confirmed in human MCF-7 breast and A2780 ovarian cancer cells. Furthermore, the biocompatibility of the copolymers was established in CHO-K1 fibroblast cells using a cell viability assay. The in vitro hydrolytic and enzymatic degradation of the micelles was also evaluated over a period of one month. The present study indicates that the MePEG-b-PVL copolymers are suitable biomaterials for hydrophobic drug formulation and delivery. 相似文献
20.
Friedrich Ehrendorfer 《Plant Systematics and Evolution》1977,126(4):405-408
Galium suberosum
Sibth. etSm. belongs toAsperula sect.Thliphthisa; the taxonomic transfer and a new name are therefore necessary:Asperula cypria
Ehrend. is endemic on the isle of Cyprus. Its closest affinities are withA. antalyensis
Ehrend. in S.W. Anatolia. 相似文献