Maximum Binding Capacity Research Articles

Interaction of lipophorin with Rhodnius prolixus oocytes: biochemical properties and the importance of blood feeding

Lipophorin (Lp) is the main haemolymphatic lipoprotein in insects and transports lipids between different organs. In adult females, lipophorin delivers lipids to growing oocytes. In this study, the interaction of this lipoprotein with the ovaries of Rhodnius prolixus was characterised using an oocyte membrane preparation and purified radiolabelled Lp (125I-Lp). Lp-specific binding to the oocyte membrane reached equilibrium after 40-60 min and when 125I-Lp was incubated with increasing amounts of membrane protein, corresponding increases in Lp binding were observed. The specific binding of Lp to the membrane preparation was a saturable process, with a Kdof 7.1 ± 0.9 x 10-8M and a maximal binding capacity of 430 ± 40 ng 125I-Lp/µg of membrane protein. The binding was calcium independent and pH sensitive, reaching its maximum at pH 5.2-5.7. Suramin inhibited the binding interaction between Lp and the oocyte membranes, which was completely abolished at 0.5 mM suramin. The oocyte membrane preparation from R. prolixus also showed binding to Lp from Manduca sexta. When Lp was fluorescently labelled and injected into vitellogenic females, the level of Lp-oocyte binding was much higher in females that were fed whole blood than in those fed blood plasma.

Interaction of lipophorin with Rhodnius prolixus oocytes: biochemical properties and the importance of blood feeding.

Lipophorin (Lp) is the main haemolymphatic lipoprotein in insects and transports lipids between different organs. In adult females, lipophorin delivers lipids to growing oocytes. In this study, the interaction of this lipoprotein with the ovaries of Rhodnius prolixus was characterised using an oocyte membrane preparation and purified radiolabelled Lp (125I-Lp). Lp-specific binding to the oocyte membrane reached equilibrium after 40-60 min and when 125I-Lp was incubated with increasing amounts of membrane protein, corresponding increases in Lp binding were observed. The specific binding of Lp to the membrane preparation was a saturable process, with a K(d) of 7.1 ± 0.9 x 10-8M and a maximal binding capacity of 430 ± 40 ng 125I-Lp/µg of membrane protein. The binding was calcium independent and pH sensitive, reaching its maximum at pH 5.2-5.7. Suramin inhibited the binding interaction between Lp and the oocyte membranes, which was completely abolished at 0.5 mM suramin. The oocyte membrane preparation from R. prolixus also showed binding to Lp from Manduca sexta. When Lp was fluorescently labelled and injected into vitellogenic females, the level of Lp-oocyte binding was much higher in females that were fed whole blood than in those fed blood plasma.

Preparation and Characterization of Molecularly Imprinted Polymer as SPE Sorbent for Melamine Isolation

In this paper, a separation procedure combining molecularly imprinted-solid phase extraction (MI-SPE) was developed for the isolation of melamine. The molecularly imprinted polymer (MIP) was prepared using precipitation polymerization method where melamine as template, 9-vinylcarbazole as functional monomer, ethtylene glycol dimethacrylate as a cross-linker and benzoyl peroxide as initiator. An off-line MI-SPE method followed by ultra-performance liquid chromatography detection of melamine was established. MIP showed a better affinity toward melamine compared to non imprinted polymer (NIP) with a maximum binding capacity of 53.01 mg/g MIP. Based on the correlation coefficients, the kinetic study indicated that the adsorption of melamine by MIP fit a pseudo-second order model. From isotherm study, adsorption of melamine by MIP increased when the concentration of melamine increased and followed a Freundlich isotherm model, which indicates the sorption can be described by multilayer sorption. The interference study proved that MIP has better binding capacity towards melamine if compared to NIP due to specific sites of melamine occurred in MIP particles.

Characterization of pandemic influenza A (H1N1) virus hemagglutinin specific polyclonal antibodies for biosensor applications

In this study, recombinant hemagglutinin protein (rH1N1HA) of Pandemic influenza virus and polyclonal antibodies against it for biosensor applications have been characterized. For rapid and high sensitive detection of H1N1 virus or its antibodies, PCR-free and label free detection method based on a surface plasmon resonance technique has been proposed. The glycosylated H1N1HA protein was expressed in yeast and the authenticity of the expressed protein was confirmed by Western blotting. Rabbit polyclonal antibodies developed against rH1N1HA protein were evaluated for their ability to neutralize H1N1 virus through plaque reduction neutralization test and indirect ELISA. Affinity purified anti-H1N1HA IgG were characterized further for their specificity, affinity of interaction, the association and dissociation rates at which they interact through surface plasmon resonance technique. The equilibrium constant and maximum binding capacity of analyte was found to be 49.7 nM and 47.28m°, respectively. The assay could detect a lowest IgG of 0.5 ng on a rH1N1HA coated chip. Combined with the high sensitivity of surface plasmon resonance technique and specificity of the reagents, it is possible to develop a rapid detection assay for monitoring influenza infections.

A Surface Molecularly Imprinted Polymer for Selective Extraction and Liquid Chromatographic Determination of 4-Methylimidazole in Environmental Samples

A newly designed surface molecularly imprinted polymer (MIP) was developed using 4-methylimidazole as the template and ethylenediaminepoly (styrene-divinylbenzene) particles as the support material. The resulting MIP material was characterized with scanning electron microscopy, infrared spectrum, surface area, pore-size and thermal property measurements. Static adsorption, solid-phase extraction (SPE) and high-performance liquid chromatography were combined to study the adsorption characteristics and selective recognition performance of the polymer for 4-methylimidazole and its structural analogues. It was shown that the maximum binding capacities of 4-methylimidazole on the MIP and the non-imprinted polymer (NIP) were 416 and 227 μmol g-1, respectively. The binding process could be described by pseudo-second-order kinetics, and the adsorption equilibrium was achieved in 40 minutes. Compared with the corresponding NIP, the MIP exhibited much higher adsorption performance and selectivity for the template. ...

Characteristics and Functional Relevance of Apolipoprotein-A1 and Cholesterol Binding in Mammary Gland Tissues and Epithelial Cells

Cholesterol in milk is derived from the circulating blood through a complex transport process involving the mammary alveolar epithelium. Details of the mechanisms involved in this transfer are unclear. Apolipoprotein-AI (apoA-I) is an acceptor of cellular cholesterol effluxed by the ATP-binding cassette (ABC) transporter A1 (ABCA1). We aimed to 1) determine the binding characteristics of 125I-apoA-I and 3H-cholesterol to enriched plasma membrane vesicles (EPM) isolated from lactating and non-lactating bovine mammary glands (MG), 2) optimize the components of an in vitro model describing cellular 3H-cholesterol efflux in primary bovine mammary epithelial cells (MeBo), and 3) assess the vectorial cholesterol transport in MeBo using Transwell® plates. The amounts of isolated EPM and the maximal binding capacity of 125I-apoA-I to EPM differed depending on the MG’s physiological state, while the kinetics of 3H-cholesterol and 125I-apoA-I binding were similar. 3H-cholesterol incorporated maximally to EPM after 25±9 min. The time to achieve the half-maximum binding of 125I-apoA-I at equilibrium was 3.3±0.6 min. The dissociation constant (KD) of 125I-apoA-I ranged between 40–74 nmol/L. Cholesterol loading to EPM increased both cholesterol content and 125I-apoA-I binding. The ABCA1 inhibitor Probucol displaced 125I-apoA-I binding to EPM and reduced 3H-cholesterol efflux in MeBo. Time-dependent 3H-cholesterol uptake and efflux showed inverse patterns. The defined binding characteristics of cholesterol and apoA-I served to establish an efficient and significantly shorter cholesterol efflux protocol that had been used in MeBo. The application of this protocol in Transwell® plates with the upper chamber mimicking the apical (milk-facing) and the bottom chamber corresponding to the basolateral (blood-facing) side of cells showed that the degree of 3H-cholesterol efflux in MeBo differed significantly between the apical and basolateral aspects. Our findings support the importance of the apoA-I/ABCA1 pathway in MG cholesterol transport and suggest its role in influencing milk composition and directing cholesterol back into the bloodstream.

Study on directional separation of picroside Ⅱ from extract of traditional Chinese medicine by molecularly imprinted technology

Picroside II, separated from Chinese herbal medicine, is an active compound with neroprotective activity. Molecularly imprinted polymers (MIPs) have high affinity toward template molecules synthesized by molecularly imprinted technology for its specific combined sites, which can overcome the shortcomings of traditional separation methods, such as complex operation and low efficiency. In this paper, MIPs were prepared by precipitation polymerization with picroside II as the template molecule, 1-vinylimidazole (1-Vinyl) as functional monomer, ethylene glycol dimethacrylate (EDMA) as cross-linker. The morphology of MIPs was characterized by scanning electronmicroscope (SEM) and its static adsorption capacity was measured by the scatchard equation. The results showed that picroside II MIPs have spherical shape, and most of them are uniform in size. Furthermore, the maximum binding capacity (Q(max)) of MIPs is 3.02 mg x g(-1), higher than that of non-imprinted polymers (NIPs). This result indicated that picroside II MIPs with good morphology and high targeted affinity toward the template molecules can be prepared by precipitation polymerization, which can be used to separate picroside II and its analogies from extract of Chinese herbal medicine. In addition, this method has the advantages of good environment and simple operation, which might offer a novel method for the efficient separation of picroside II in the traditional herbal medicines.

Synthesis and Evaluation of Molecularly Imprinted Polymeric Microspheres for Chloramphenicol by Aqueous Suspension Polymerization as a High Performance Liquid Chromatography Stationary Phase

School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing 100083, ChinaReceived March 13, 2013, Accepted March 30, 2013Molecularly imprinted microsphere for chloramphenicol (CAP) with high adsorption capacity and excellentselectivity is prepared by aqueous suspension polymerization, in which chloramphenicol is used as templatemolecule and ethyl acetate as porogen. The CAP-imprinted microspheres are used as high performance liquidchromatography (HPLC) stationary phase and packed into stainless steel column (150 mm × 4.6 mm i.d.) forselective separation of chloramphenicol. HPLC analysis suggests that chloramphenicol can be distinguishedfrom not only its structural analogs but also other broad-spectrum antibiotic such as erythromycin andtetracycline. In addition, the binding experiments of CAP-imprinted microspheres are carried out in ethanol/water (1:4, V:V), the results indicate that the maximum apparent static binding capacity of molecularlyimprinted microspheres is up to 66.64 mg g

Regenerable hydrogels based on poly(acrylic acid-sodium acrylate-acrylamide) modified by sodium humate for high removal of Pb2+ and Fe2+ ions: metal adsorption kinetics and thermodynamic studies

ABSTRACTA novel superabsorbent hydrogel based on poly(acrylic acid-sodium acrylate-acrylamide)/sodium humate poly(AAc-SA-AM)/SH was applied as adsorbent to adsorb metal ions (Pb2+, Fe2+) from the aqueous solutions. The factors affecting adsorption capacity of the poly(AAc-SA-AM)/SH hydrogel such as contact time, pH, temperature, SH content (wt.%), initial concentration of the metal ion, and ionic strength were systematically investigated. Results from the experimental data revealed that an appropriate addition of SH (2.44 wt.%) not only increases the metal ion adsorption of poly(AAc-SA-AM) hydrogel but also improves its regeneration ability. The results showed that the adsorption equilibrium data fitted the Langmuir isotherm better than the Freundlich isotherm. The maximum binding capacity for Pb2+ ion was 198 and 164 mg/g/l for Fe2+ ion for per g of poly(AAc-SA-AM)/SH (SH4) hydrogel (high as compared to many other adsorbents). The changes in thermodynamic parameters were also calculated, and the negative...

Development and characterisation of an immunoaffinity column for the selective extraction of methandrostenolone from food and feed samples

Methandrostenolone (MA) is used as veterinary medicine for promoting food-producing animal growth. Accumulation of MA in a human body would cause multiple side effects. In this study, an anti-MA monoclonal antibody (mAb)-based immunoaffinity column (IAC) was prepared and its application to the selective extraction of MA from actual samples was evaluated. The employed antibody exhibited good sensitivity and specificity towards MA with an IC50 value of 7.89 ng/mL and less than 1% cross-reactivity towards structurally related compounds. By coupling CNBr-activated Sepharose with the antibody, an IAC was prepared. Two percent methanol and 70% methanol were selected, respectively, as loading and eluting solution by optimisation. The maximum binding capacity of the column for MA reached 4760 ng/mL gel. The average recovery of 50, 250 and 500 ng MA standards from IACs was 88.6% with a relative standard deviation (RSD) among columns of 8.5%. After three times usage, the binding capacity and recovery still remained 93.4% and 81.1%, respectively. To further verify the effect of matrices on the extraction efficiency, the IACs were challenged with MA-fortified animal tissue and feed samples and the recovery were found to be in the range of 78.7%–95.1%.

Silylated montmorillonite based molecularly imprinted polymer for the selective binding and controlled release of thiamine hydrochloride

In the present study, specific binding and controlled release of thiamine hydrochloride (THC) to and from a novel molecularly imprinted polymer (MIP) matrix namely, THC-templated-silylated montmorillonite-itaconic acid polymer was investigated. The polymer matrix was characterized by means of XRD, FTIR and SEM analyses. Optimization of various imprinting components and binding characteristics of THC by the novel MIP were examined in detail. The binding affinity of THC for MIP was found to be greater than that for non-imprinted polymer (NIP). The maximum binding was found to be at solution pH of 4.5. The Sips isotherm model was found to describe well the equilibrium binding data with maximum binding capacity of 100mg/g for MIP. The kinetic study revealed that the binding of THC onto MIP follows pseudo-second-order kinetic model with correlation coefficient 0.999. The swelling study of MIP in distilled water showed that the maximum swelling capacity is 329.0g/g at about 8h. In vitro release experiments showed that MIP releases drug in intestinal fluid with a controlled manner. The release kinetics of drug from MIP was analyzed using Ritger–Peppas model. The binding specificity of MIP for THC was tested using different substrates having structural analogue to the template, THC.

COMPONENTS SCREENING FROM CURCUMA LONGA LINN. AND THEIR BIOAFFINITY PROPERTY ON HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS BY CELL MEMBRANE CHROMATOGRAPHY

Curcuma longa Linn. (CLL) is widely used as a traditional herbal medicine for the prevention of diabetic vascular complications, but the potential active compounds and its bioaffinity property to cells remain obscure. In this study, cell membrane chromatography (CMC) was used to screen the active components binding to human umbilical vein endothelial cells (HUVECs). Demethoxycurcumin and curcumin in CLL were identified as two cells-binding compounds. MTT and acridine orange-ethidium bromide (AO-EB) results demonstrated demethoxycurcumin and curcumin had protection activity on advanced glycation end products (AGEs)-induced HUVECs damage, including increasing cell viability and reducing apoptosis. CMC was also used to determine the bioaffinity property of these compounds to cells. The dissociation equilibrium constants (Kd) of demethoxycurcumin and curcumin were 3.173 ± 0.46 and 3.088 ± 0.51 nM. Maximum binding capacities (Bmax) were 22.61 ± 3.74 and 24.39 ± 2.11 fmol · mg−1 protein. The IC50 of demethoxycurcumin and curcumin were (2.50 ± 0.16) and (1.59 ± 0.28) × 10−7 M, respectively. Our results indicated that demethoxycurcumin and curcumin were the potential active compounds in CLL for the prevention of diabetic vascular complications, and CMC provided a rapid and efficient method for screening potential active components in traditional Chinese medicines against diabetic vascular complications.

Selection and characterization of peptides binding to diamond-like carbon

Phage display was used to find peptides specific for amorphous diamond-like carbon (DLC). A set of putative binders was analyzed in detail and one sequence was found that functioned both as a peptide fused to the pIII protein in M13 phage and as a peptide fused to the enzyme alkaline phosphatase (AP). The dissociation constant of the peptide–AP fusion on DLC was 63nM and the maximum binding capacity was 6.8pmol/cm2. Multiple ways of analysis, including phage titer, enzyme-linked immunosorbent assay, and ellipsometry were used to analyze binding and to exclude possible false positive results. DLC binding peptides can be useful for self-assembling coatings for modifying DLC in specific ways.

Synthesis, optimization, and characterization of molecularly imprinted nanoparticles

Nanoparticles of molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization method. Glucose was used as a template molecule. The impact of different process parameters on the preparation of nanoparticles was investigated in order to reach the maximum binding capacity of MIPs. Experimental data based on uniform design were analyzed using artificial neural network to find the optimal condition. The results showed that the binding ability of nanoparticles of MIPs prepared under optimum condition was much higher than that of the corresponding non-imprinted nanoparticles (NIPs). The findings also demonstrated high glucose selectivity of imprinted nanoparticles. The results exhibited that the particle size for MIP nanoparticles was about 557.6 nm, and the Brunauer-Emmett-Teller analysis also confirmed that the particle pores were mesopores and macropores around 40 nm and possessed higher volume, surface area, and uniform size compared to the corresponding NIPs.

Surface Plasmon Resonance Sensogram Based Characterization of Antibodies Raised Against Intact Teliospores and Purified Diagnostic Antigen for Development of Nano-Immunosensor for Fungal Spore Antigen of Karnal Bunt (Tilletia indica) of Wheat

The label free real time surface plasmon resonance based immuno-sensing system was first time demonstrated in the authors’ lab using a mercaptoundecanoic acid modified gold sensor chip. The kinetics of the antigen–antibody interaction was determined for optimization of resonance signal intensity for the detection of antigen(s) of fungal teliospores-causative entities of Karnal bunt disease of wheat incited by Tilletia indica. The approach involves the use of a rabbit polyclonal (anti-teliospore) antibody and mono-specific antibody generated against intact teliospores and purified diagnostic antigen of 28 kDa protein. The sensitivity of each of these two immunosensors constructed with the different concentrations of teliosporic antigen was determined by sensogram analysis which showed detection sensitivity as low as 625 and 156 pg which is equivalent to 2.5 and 1.0 teliospores over the sensor surface by getting an angle of dip indicating greater affinity of raised anti-teliospore antibodies and monospecific antibody respectively. By using kinetic evaluation software, the equilibrium constant (KD) and maximum binding capacity of analyte (Bmax) values were calculated and found to be 3.45 and 331.8 nM respectively using polyclonal and 1.57 and 289.57 nM respectively using monospecific antibody.

Crosslinked-Chelating Porous Sheet with High Dynamic Binding Capacity of Metal Ions

A crosslinked chelating porous sheet was prepared by cografting ethylene glycol dimethacrylate (EGDMA) with glycidyl methacrylate onto an electron-beam-irradiated porous polyethylene sheet, followed by the introduction of an iminodiacetate group. At a molar percentage of EGDMA of 1.0 mol%, the sheet exhibited a maximum dynamic binding capacity for copper ions of 0.93 mmol/g, while the equilibrium binding capacity remained the same (1.2 mmol/g) as that of a non-crosslinked chelating porous sheet. The crosslinking of the grafted chain causes copper ions to lower their diffusion rate along the sheet thickness driven by the gradient of the amount of copper ions adsorbed.

Preparation of Melamine Molecularly Imprinted Polymeric Microspheres by Two-Step Seed Swelling Polymerization

Melamine molecularly imprinted polymeric microsphere (MIPM) was initially prepared by two-step seed swelling polymerization methods. Factors affecting the particle morphologies including emulsifier, dispersant, the water-oil ratio, and etc were optimized in order to obtain the MIPMs with a final narrow particle diameter of 3-5 μm. Characterization of the resulted polymeric microspheres was investigated by scanning electron microscope (SEM), infrared absorption spectroscopy (IR), and mercury analyzer (MA), respectively. When the initial concentration of melamine was 1.0 mmol L-1, the affinity capacity of MIPMs was 2.0 times than that of NIPMs. Scatchard analysis suggested melamine were recognized by the prepared MIPMs with two classes of binding sites. The apparent maximum binding capacity and dissociation constant were calculated to be 43.2 μmol g-1 (Qmax1) and 2.2×10-4 mol L-1 (Kd1) for high affinity site, whilst to be 102.3 μmol g-1 (Qmax2) and 1.3×10-3 mol L-1 (Kd2) for low affinity site, respectively. Obvious molecular effects towards melamine were further confirmed by the comparative HPLC experiments using NIPMs and MIPMs as the stationary phases, respectively.

Multi‐cycle recovery of lactoferrin and lactoperoxidase from crude whey using fimbriated high‐capacity magnetic cation exchangers and a novel “rotor–stator” high‐gradient magnetic separator

Cerium (IV) initiated "graft-from" polymerization reactions were employed to convert M-PVA magnetic particles into polyacrylic acid-fimbriated magnetic cation exchange supports displaying ultra-high binding capacity for basic target proteins. The modifications, which were performed at 25 mg and 2.5 g scales, delivered maximum binding capacities (Qmax ) for hen egg white lysozyme in excess of 320 mg g(-1) , combined with sub-micromolar dissociation constants (0.45-0.69 µm) and "tightness of binding" values greater than 49 L g(-1) . Two batches of polyacrylic acid-fimbriated magnetic cation exchangers were combined to form a 5 g pooled batch exhibiting Qmax values for lysozyme, lactoferrin, and lactoperoxidase of 404, 585, and 685 mg g(-1) , respectively. These magnetic cation exchangers were subsequently employed together with a newly designed "rotor-stator" type HGMF rig, in five sequential cycles of recovery of lactoferrin and lactoperoxidase from 2 L batches of a crude sweet bovine whey feedstock. Lactoferrin purification performance was observed to remain relatively constant from one HGMF cycle to the next over the five operating cycles, with yields between 40% and 49% combined with purification and concentration factors of 37- to 46-fold and 1.3- to 1.6-fold, respectively. The far superior multi-cycle HGMF performance seen here compared to that observed in our earlier studies can be directly attributed to the combined use of improved high capacity adsorbents and superior particle resuspension afforded by the new "rotor-stator" HGMS design.

Improved preparation of a chitosan-based immunoaffinity column using antibody against methandrostenolone as ligand

Chitosan is obtained by N-deacetylation of chitin, which is the second most abundant natural biopolymer. In this study, an improved preparation and characterisation of a chitosan-based immunoaffinity chromatography (IAC) column were performed. The immunoaffinity adsorbent was prepared by covalently coupling monoclonal antibody (mAb) against methandrostenolone (MA) to glutaraldehyde cross-linked chitosan (chitosan CL). Scanning electron micrograph of chitosan CL indicated that the shape of the particles was spherical with a diameter range from about 300 to 500 µm. Infrared spectral analysis suggested that the immunoaffinity adsorbent was successfully prepared by coupling antibody with chitosan CL. For chromatographic extraction, 90% methanol was selected as eluant. Under optimum conditions, the maximum binding capacity of the IAC column was 3900 ng MA/mL adsorbent. The average recovery of 50, 250 and 500 ng of MA standards from IAC columns was 96.9% with a relative standard deviation among columns of 1.48%. After eight uses, the extraction recovery of the IAC column remained 82.1%. To further verify the effect of matrices on the extraction efficiency, the IAC columns were challenged with MA-fortified animal tissue and feed samples. Recoveries were 84.9–87.1%, demonstrating the effectiveness of these IAC columns for sample clean-up in MA residue determination.

Potent Retro-Inverso d-Peptide for Simultaneous Targeting of Angiogenic Blood Vasculature and Tumor Cells

The application of tumor targeting ligands for the treatment of cancer holds the promise of enhanced efficacy and reduced toxicity. L-SP5 ((L)(SVSVGMKPSPRP)) is a peptide that recognizes tumor neovasculature but not normal blood vessels (Lee et al., Cancer Res.2007, 67, 10958-65). The current report presents the design and application of D-SP5 ((D)(PRPSPKMGVSVS)), a novel retro-inverso analogue of L-SP5. Peptides D-SP5 and parental L-SP5 are shown to compete for the same target sites of a yet unknown cellular target and possess a dual-targeting bioactivity for both activated endothelial cells (HUVEC) and several tumor cell lines. Cellular uptake experiments showed superior in vitro targeting abilities of D-SP5 compared with L-SP5, such as enhanced internalization into stimulated HUVEC or KB, U87, and SGC tumor cells. A radioligand receptor binding assay revealed a higher cell affinity of D-SP5 in all tested cell lines, with K(d) values for D-SP5 about 2-fold lower than for L-SP5. An up to 3-fold higher maximum binding capacity (B(max)) to cells of D-SP5 was noted. Fluorescein-labeled D-SP5 upon intravenous administration displayed strong association with tumor endothelium. D-SP5-conjugated PEG-DSPE micelles displayed enhanced tumor homing (evidenced by near-infrared in vivo imaging). When loaded with doxorubicin, D-SP5 micelles could markedly suppress tumor growth with higher efficacy than L-SP5 micelles both in vitro and in vivo in KB tumor xenografts. In summary, the data demonstrate that D-SP5 displays higher binding affinities toward tumor endothelium as well as tumor cells and enhanced tumor targeting capability in vitro and in vivo.