Comparison of biological characteristics of human adipose- and umbilical cord- derived mesenchymal stem cells and their effects on delaying the progression of osteoarthritis in a rat model.

BACKGROUND: The prevalence of osteoarthritis (OA) is constantly increasing with age. Adipose-derived (AD-) and umbilical cord-derived (UC-) mesenchymal stem cells (MSCs) are attractive alternatives in OA therapy and regenerative medicine. However, whether there are differences in the efficacy of MSCs derived from different tissues in the cartilage regeneration, and the frequency of administration of MSCs needs to be further studied. EXPERIMENT: UC-MSCs and AD-MSC were isolated from the umbilical cord and subcutaneous fatty tissue of humans respectively and identified by flow cytometry. In vitro, the proliferation ability and chondrogenic potential of AD-MSCs and UC-MSCs were analyzed. In vivo, forty-three Sprague-Dawley rats were used for the OA model induced by ACLT surgery. OA rats were divided into a sham group, an ACLT model group, and two therapy groups (treated with AD-MSCs or UC-MSCs). Therapy groups were treated using a single or repeated twice injection of AD-MSCs and UC-MSCs at a concentration of 1.0 × 106 cells and were followed up for 12 weeks. Serial sections of knees were examined for histological, immunohistochemical and TUNEL analysis. RESULTS: We demonstrated that the proliferation of UC-MSCs was higher than that of AD-MSCs, consistent with the bigger pellets from UC-MSCs in a chondrogenic induction medium. Degeneration of articular cartilage was observed in histological appearance of Safranine O and Toluidine blue staining, and quantitative results of modified Mankin's Score. Importantly, both AD-MSCs and UC-MSCs transplantation significantly attenuated ACLT surgical-induced OA development. In addition, ACLT-induced reduction in cartilage extracellular matrix synthesis (aggrecan) was significantly suppressed by AD-MSCs or UC-MSCs transplantation. TUNEL assay showed that AD-MSCs and UC-MSCs treatments significantly protected chondrocytes against apoptosis compared with the ACLT group. No significant differences were observed between single injections and repeated twice injections. CONCLUSIONS: The current study suggested that, in vitro, AD-MSCs and UC-MSCs showed a comparable chondrogenic potential, although UC-MSCs displayed a superior proliferation capacity. Furthermore, our results confirmed that the injection of AD-MSCs and UC-MSCs, either single or repeated twice, could significantly inhibit the progression of ACLT-induced osteoarthritis with a similar effect, and MSCs transplantation can decrease the apoptosis of articular chondrocytes caused by ACLT.

[Research Progress in the Odorants and Their Emissions from Indoor Building Decoration Materials].

The emission of pollutants from building decoration and furbishing materials associated with unpleasant odors is the main reason for complaints relating to poor quality indoor air. Currently, few studies have focused on the identification of odorants and the quantification of emissions from these building materials. Here, we summarize the analytical methods available for the study of indoor odorants and evaluate existing understanding of odorants from nine kinds of building materials, namely plaster board, wood-based materials, linoleum, carpets, plastics, rubber, artificial leather, paints, and adhesives. The possible odor-causing compounds emitted by these different materials and their odor threshold values are identified. Finally, suggestions are proposed for future research and control measures to minimize indoor odor pollution. Overall, olfactometry is the most important tool for odor analysis desite the non-standardized application of the technique when used in the assessment of odor emissions from building materials. In addition, there are large differences in the reported patterns of odorant emissions from building materials, although oxidized substances such as aldehydes, ketones, and acids are frequently identified in association with the aging of the materials via processes such as oxidation and ozone degradation over time.

The Influence of CTAB-Capped Seeds and Their Aging Time on the Morphologies of Silver Nanoparticles.

Contrast to the polydisperse nanorods formed by common seed-mediated growth method without the presence of cetyltrimethylammonium bromide (CTAB) in seed solution, we successfully obtained silver nanoparticles with different morphologies in the same reaction system by addition of CTAB in the seed solution. In this work, an appropriate amount of CTAB was added into the solution to prepare silver seed crystals. The results show that the aging time of silver seeds have a great influence on the sizes and morphologies of silver nanoparticles and thus the shape-controllable silver nanoparticles can be easily achieved by simply changing the seed aging time. The results also support that the selective adsorption ability or adsorption behavior of TSC can be adjusted by adding CTAB in the preparation procedure of silver seeds. We suggest that different aging times generate different effects on the competitive adsorption between CTAB and citrate to induce the orientation growth of silver seeds. As a result, silver nanospheres, nanorods, and triangular nanoplates can be easily prepared in the same system. In addition, we overcome the time limitation about the use of the seeds by adding CTAB into seed solution and make the synthesis of silver or other metal nanoparticles with different morphologies more easily and more efficiently.

Engineer biomolecules by linking desired properties with phage propagation.

Genetic diversity promotes laboratory based evolution and researchers can use mutagenesis and artificial selection to acquire expected phenotypes more frequently. Continuous evolution makes the important steps of laboratory evolution integrated into an uninterrupted cycle, enabling more generations to be evolved and scarcely any human interventions. Phages such as X174, T7 and λ bacteriophages with ideal mutation rates and feasibility to manipulate have been developed as an excellent platform for in vivo continuous evolution. Researchers at Harvard have recently invented an innovative system for the directed evolution of interested biomolecules: phage-assisted continuous evolution (PACE). PACE enables researchers to evolve biomolecules with desired properties within a very short time, which can perform more than 40 rounds of evolution in one day. Up to now, RNAP, protease, gene editing tool, receptor binding protein, aminoacyl-tRNA synthetase and single-chain variable fragments (scFv) have been optimized and evolved with improved activities and specificities by PACE. In addition, two simplified versions of PACE (PRECEL, PANCE) and a novel M13 phagemid-based system have been developed to expand the toolkit of directed evolution. It is promising and exciting that potentially any disease-related molecules which link desired activities with phage propagation can be optimized by above phage-assisted systems, thus leading to more potent biological therapies to be developed and applied into the clinic.

Antimicrobial activity of X zeolite exchanged with Cu2+ and Zn2+ on Escherichia coli and Staphylococcus aureus.

The biocidal cations of Cu2+ and Zn2+ were hosted on the surfaces and in the cavities of X zeolite via ion exchange. The microstructure and interface properties of the exchanged zeolite X samples were analyzed by XRD, SEM, XPS, and XRF. The as-prepared samples showed excellent antimicrobial activity towards gram-negative bacteria of Escherichia coli and gram-positive bacteria of Staphylococcus aureus. Furthermore, the batch antimicrobial experiments showed that the bacterial disinfection process fitted well with the first order model. The Cu2+-zeolite showed excellent and better antibacterial performance on S. aureus than on E. coli, and the mortalities of E. coli and S. aureus were almost 100% after 1 h with the initial Cu2+-zeolite concentrations of 1000 ppm and 100 ppm, respectively. However, the Zn2+-zeolites were found to be less effective on S. aureus than on E. coli, and the mortalities of E. coli and S. aureus were almost 100% after 1 h with the initial Zn2+-zeolite concentrations of 500 ppm and 1000 ppm, respectively. In addition, the relationships between the apparent rate constant (k) and reagent concentration (C) were also systematically investigated. The present results suggest that the as-prepared samples could be promising antibacterial materials for the efficient disinfection of contaminated water with bacteria.

Visible-Light-Driven Catalytic Disinfection of Staphylococcus aureus Using Sandwich Structure g-C3N4/ZnO/Stellerite Hybrid Photocatalyst.

A novel g-C3N4/ZnO/stellerite (CNZOS) hybrid photocatalyst, which was synthesized by coupled hydro thermal-thermal polymerization processing, was applied as an efficient visible-light-driven photocatalyst against Staphylococcus aureus. The optimum synthesized hybrid photocatalyst showed a sandwich structure morphology with layered g-C3N4 (doping amount: 40 wt%) deposited onto micron-sized ZnO/stellerite particles (ZnO average diameter: ~18 nm). It had a narrowing band gap (2.48 eV) and enlarged specific surface area (23.05 m²/g). The semiconductor heterojunction effect from ZnO to g-C3N4 leads to intensive absorption of the visible region and rapid separation of the photogenerated electron-hole pairs. In this study, CNZOS showed better photocatalytic disinfection efficiency than g-C3N4/ZnO powders. The disinfection mechanism was systematically investigated by scavenger-quenching methods, indicating the important role of H2O2 in both systems. Furthermore, h⁺ was demonstrated as another important radical in oxidative inactivation of the CNZOS system. In respect of the great disinfection efficiency and practicability, the CNZOS heterojunction photocatalyst may offer many disinfection applications.

A novel stellerite-based photocatalytic composite and its enhanced disinfection application.

The aim of this work was to prepare, characterize and evaluate the potential of novel ZnO/stellerite composite photocatalysts against Staphylococcus aureus (S. aureus). SEM/EDS studies employed to study the surface morphological properties revealed stellerite as the catalysts carrier played a role of dispersant for ZnO nanoparticles. The XRD patterns of the ZnO/stellerite indicated hexagonal crystal structure with 20-30 nm size. It was found that the crystallite size of ZnO/stellerite was much smaller as compared to pure ZnO and increased with increasing ZnO loading amount. The results of optical properties of ZnO/stellerite showed smaller band gap in contrast to pure ZnO, investigated by UV-vis absorption. Due to the optimum ZnO loading, the as-prepared ZnO-20 composite had the highest BET surface area and the pore volume. Using the TG-DSC measurement, the high thermal stability of the product was studied for different temperature values. Antibacterial activity of ZnO/stellerite affected by the ZnO loading, concentration of samples and light conditions (under dark and UV irradiation conditions) was examined by disinfection of S. aureus. The as-prepared ZnO-20 composite with 100 mg/L was found to exhibit excellent inactivation efficiencies (87.65% in the dark and 97.67% under UV illumination) towards S. aureus. Compared with pure ZnO, the obtained composite photocatalysts showed significantly better antibacterial performance by studying the disinfection kinetics of S. aureus. Thus, the present study reveals that the novel ZnO/stellerite shows great potential for its use in the targeted disinfection applications.

Preparation of triangular silver nanoplates by silver seeds capped with citrate-CTA.

Due to the competitive growth on the crystal face of seed, it is always difficult to control the morphology of the formation of nanoparticles precisely by a seed-mediated growth method. Herein, we provided a simple but effective technique to synthesize silver nanotriangles using a new silver seed that is capped with citrate-CTA+ (CTA+ is cetyltrimethyl ammonium cation). Compared to the preparation of silver nanoparticles (AgNPs) by a conventional seed-mediated method, in this paper, we presented a growth technique with two distinct innovative changes. First, the concentrations of CTAB that we added in silver seed collosol have a significant impact on the size distribution, and silver nanotriangles, nanorods, and nanospheres could be obtained by adjusting the CTAB concentration. Second, the seed prepared by our method has a longer use time, and silver nanotriangles, nanospheres, and nanorods could be prepared by adjusting the aged time of the seed colloid. We have also shown a simple way to control the morphology of silver nanoparticles in almost the same reactive medium by varying the NaOH concentration. Using the new silver seed capped with citrate-CTA+, we obtained triangular silver nanoparticles with relatively high regularity. Based on the limited experimental results and IR analysis, a possible mechanism was preliminarily proposed to explain the formation of the seed and the truncated triangular AgNPs.

pH Dependent synthesis of two isomeric dinuclear Cerium(II) complexes: Structures, DNA interactions, cytotoxic activity and apoptotic study.

Two isomeric dinuclear Cerium(II) complexes 1 and 2, formulated as Ce2(phen)2(NO3)2(L)4 [L=phenylacetic acid, phen=1,10-phenanthroline] was synthesized under solvothermal conditions at different pH values. The two complexes were characterized by elemental analysis, IR and single crystal X-ray diffraction. Complexes 1 and 2 were studied the binding with DNA and against cytotoxic activity. Fluorescence analysis indicated that the two complexes can bind to DNA. The changes with different gradient concentration of DNA added into the complexes in absorption spectra show a strongπ-stacking interaction between the complexes and DNA base pairs. The Cerium(II) complexes showed good cytotoxic activity against cancer cell lines, being 2 the most potent complex. Apoptotic studies of the two novel dinuclear complexes showed significant inhibitory rate on cancer cell growth line KB.

The Syntheses, Structures, Fluorescence Properties and Biological Activity of two Novel Zinc(II) Complexes Controlled by the Tripodal Imidazole Ligand.

Two new zinc complexes, namely Zn(L(1))ClCH2NO(1) and {Zn(L(2))CH2NO}n▪N(CH3)3▪ClO4(2) (L(1) = 3,5-di(1H-imidazol-1-yl)pyridine L(2) = 1,3,5-tris(1-imidazolyl) benzene), have been synthesized, and characterized by IR spectra, elemental analysis, and a single crystal X-ray diffraction. Fluorescence spectroscopy indicated that two complexes presented strong DNA binding affinity constants to fish sperm DNA (FS-DNA). Gel electrophoresis assay demonstrated the ability of the complex to cleave the HL-60 DNA. Apoptotic study showed the complex exhibited significant cancer cell(KB) inhibitory rate.

Novel palladium(II) complexes containing a sulfur ligand: structure and biological activity on HeLa cells.

Two novel palladium(II) complexes with a thiosalicylic acid (HSC(6)H(4)CO(2)H) ligand, with the formulas [Pd(TSA)(L)]·mH(2)O (TSA is thiosalicylic acid; in complex 1, L is 1,10-phenanthroline and m = 1; in complex 2, L is 2,2'-bipyridine and m = 2), have been synthesized and characterized. The coordination geometry of both palladium atoms is square planar; they are four-coordinated and each is coordinated in an N,N,O(-),S(-) mode. There is a sigmoid oxygen chain in complex 1, but an oxygen ring in complex 2. The competitive binding of the complexes to HeLa cell DNA (HL-DNA) has been investigated by fluorescence spectroscopy. The results show that the two complexes have the ability to bind with HL-DNA. Viscosity studies suggest that the complexes bind to DNA by intercalation. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the HL-DNA. The two complexes exhibit cytotoxic specificity and a significant cancer cell inhibitory rate. The apoptosis tests indicated that the complexes have an apoptotic effect. Furthermore, complex 1 exhibits more biological activity than complex 2, which is mainly because the area of the aromatic ring of 1,10-phenanthroline is larger than that of 2,2'-bipyridine.

Synthesis, characterization, interaction with DNA, and cytotoxic effect in vitro of new mono- and dinuclear Pd(II) and Pt(II) complexes with benzo[d]thiazol-2-amine as the primary ligand.

A series of novel Pd(II) and Pt(II) complexes, [PdL(2)Cl(2)]·DMF (1), [Pd(2)(L-H)(2)(bpy)Cl(2)]·(H(2)O)(2)·DMF (2), [Pd(2)(L-H)(2)(phen)Cl(2)]·2H(2)O (3), [PtL(2)Cl(2)]·H(2)O (4), [Pt(2)(L-H)(2)(bpy)Cl(2)]·2H(2)O (5), and [Pt(2)(L-H)(2)(phen)Cl(2)]·H(2)O (6), where bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, and L = 1,3-benzothiazol-2-amine, have been synthesized and characterized. The competitive binding of the complexes to DNA has been investigated by fluorescence spectroscopy. The values of the apparent DNA binding constant, calculated from fluorescence spectral studies, were 3.8 × 10(6) (K(app)(4)), 2.9 × 10(6) (K(app)(1)), 2.4 × 10(6) (K(app)(6)), 2.0 × 10(6) (K(app)(5)), 1.2 × 10(6) (K(app)(3)), and 6.9 × 10(5) (K(app)(2)). The binding parameters for the fluorescence Scatchard plot were also determined. On the basis of the data obtained, it indicates that the six complexes bind to DNA with different binding affinities in the relative order 4 > 1 > 6 > 5 > 3 > 2. Viscosity studies carried out on the interaction of complexes with Fish Sperm DNA (FS-DNA) suggested that all complexes bind by intercalation. Gel electrophoresis assay demonstrates that all the complexes can cleave the pBR 322 plasmid DNA and bind to DNA in a similar mode. The cytotoxic activity of the complexes has been also tested against four different cancer cell lines. The results show that all complexes have activity against KB, AGZY-83a, Hep-G2, and HeLa cells. In general, the Pt(II) complexes were found to be more effective than the isostructural Pd(II) complexes. The mononuclear complexes exhibited excellent activity in comparison with the dinuclear complexes in these four cell lines. Moreover, on the KB cell line (the human oral epithelial carcinoma), the observed result seems quite encouraging for the six complexes with IC(50) values ranging from 1.5 to 8.6 µM. Furthermore, apoptosis assay with hematoxylin-eosin staining shows treatment with the six complexes results in morphological changes of KB cells. The results induce apoptosis in KB cells.

Impact of the carbon chain length of novel palladium(II) complexes on interaction with DNA and cytotoxic activity.

A series of Pd(II) complexes with a benzenealkyl dicarboxlate chain, with the formulas [Pd(L(n))(bipy)].mH(2)O (bipy = 2,2'-bipyridine, complex 1: L(1) = phenylmalonate, m = 2.5; complex 2: L(2) = benzylmalonate, m = 1; complex 3: L(3) = phenethylmalonate, m = 2; complex 4: L(4) = phenylpropylmalonate, m = 5), have been prepared in an attempt to correlate factors about the carbon chain of the compounds with DNA binding and cytotoxic activity. The binding of complexes with fish sperm DNA (FS-DNA) was carried out by UV absorption and fluorescence spectra. A gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic effects of these complexes were examined on four cancer cell lines, HeLa, Hep-G2, KB, and AGZY-83a. The four complexes exhibited cytotoxic specificity and a significant cancer cell inhibitory rate. An apparent dependence of DNA-binding properties and cytotoxicity on the carbon chain length was obtained: the longer the carbon chain length, the higher the efficiency of DNA-binding and the greater the cytotoxicity.

Synthesis, characterization, interaction with DNA and cytotoxicity in vitro of the complexes [M(dmphen)(CO3)].H2O [M=Pt(II), Pd(II)].

The complexes [Pt(dmphen)CO3].H2O (1), [Pd(dmphen)CO3].H2O (2) (dmphen is 2,9-dimethyl-1,10-phenanthroline) have been synthesized and characterized. The binding of the complexes with FS-DNA was investigated by UV spectrum and fluorescence spectrum, showing that the complexes have the ability of interaction with DNA of intercalative mode. The intrinsic binding constant K of the complexes with FS-DNA is 1.8 x 10(5) M(-1) (1) and 1.6 x 10(4) M(-1) (2), respectively. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pBR 322 plasmid DNA. Evaluation of cytotoxic activity of the complexes against four different cancer cell lines proved that the complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate.

[Controllable synthesis and UV-Vis spectral analysis of silver nanoparticles in AOT microemulsion].

Colloidal silver nanoparticles were synthesized in water-in-oil microemulsion using silver nitrate solubilized in the water core of a microemulsion as source of silver ions, hydrazine hydrate solubilized in the water core of another one as reducing agent, cyclohexane as the continuous phase, and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as the surfactant. The main factors affecting the formation of silver nanoparticles were systematically studied. Ultraviolet-visible (UV-Vis) spectra were used for analyzing the effects of reaction parameters, including the type of reducing agents, the molar ratio of water to surfactant and the concentration of AgNO3 and AOT and so on, on the formation of silver nanoparticles. Original results for the controllable synthesis of silver nanoparticles were obtained when the synthesis proceeded in AOT-cyclohexane-AgNO3 microemulsion. The UV-Vis spectra of silver sols formed in the microemulsion with various parameters were studied systematically. The results show that the amount and average size of the obtained nanoparticles obviously depend on the above parameters. When the concentration of AgNO3 is lower, smaller silver nanoparticles are easy to form by increasing the concentration of AgNO3 appropriately. The higher W value was found to form larger numbers of silver nanoparticles with larger particle size. Compared to the solubility of NaBH4 in AOT reverse micelles, hydrazine hydrate is well soluble in these micelles, and thus it is favorable to reduce the silver ions solubilized in the water core of AOT-cyclohexane-AgNO3 microemulsion. The increase in the concentration of AOT induces an increase in the number of AOT micelles and a decrease in the molar ratio of water to surfactant. As a result, the solubilization capacity of reactants in the micelles increases and the radii of the micelles decrease. That is to say, with the increase in AOT concentration, the amount of the formed nanoparticles increases and the average size of the particles decreases.

Preparation of silver nanoparticles in water-in-oil AOT reverse micelles.

Colloidal silver nanoparticles were synthesized in AOT microemulsions. The effects of the precursors' concentration and the molar ratios of water to AOT on the particle size and size distribution were investigated. UV-vis spectra showed that the Ag+4 intermediates formed at low N2H4 concentration. TEM micrographs confirmed that the silver nanoparticles are all spherical with mean diameters in the range 2-5 nm and have a narrow size distribution. Not only the particle size but also the size distribution was increasing with the W value. The silver colloid has favorable stability and can be preserved for a long time without precipitation.

Tree analysis of mass spectral urine profiles discriminates transitional cell carcinoma of the bladder from noncancer patient.

BACKGROUND: Recent advances in proteomic profiling technologies, such as surface-enhanced laser desorption/ionization mass spectrometry (SELDI), have allowed preliminary profiling and identification of tumor markers in biological fluids in several cancer types and establishment of clinically useful diagnostic computational models. We developed a bioinformatics tool and used it to identify proteomic patterns in urine that distinguish transitional cell carcinoma (TCC) from noncancer. METHODS: Proteomic spectra were generated by mass spectroscopy (surface-enhanced laser desorption and ionization). A preliminary "training" set of spectra derived from analysis of urine from 46 TCC patients, 32 patients with benign urogenital diseases (BUD), and 40 age-matched unaffected healthy men were used to train and develop a decision tree classification algorithm that identified a fine-protein mass pattern that discriminated cancer from noncancer effectively. A blinded test set, including 38 new cases, was used to determine the sensitivity and specificity of the classification system. RESULTS: The algorithm identified a cluster pattern that, in the training set, segregated cancer from noncancer with sensitivity of 84.8% and specificity of 91.7%. The discriminatory pattern correctly identified. A sensitivity of 93.3% and a specificity of 87.0% for the blinded test were obtained when comparing the TCC vs. noncancer. CONCLUSIONS: These findings justify a prospective population-based assessment of proteomic pattern technology as a screening tool for bladder cancer in high-risk and general populations.

[Changes of alkaline phosphatase sugar chains in hepatocellular carcinoma tissue].

OBJECTIVE: To investigate the changes of sugar chain structures of alkaline phosphatase (ALP) in hepatoma tissue and its relation to the invasiveness of hepatocellular carcinoma (HCC). METHODS: The binding ratios of ALP from 9 normal liver tissues, 16 hepatoma tissues and 16 noncancerous tissues surrounding hepatoma were analysed by affinity chromatography on various lectin columns including leukoagglutinating phytohemagglutinin (L-PHA), lentil lectin (LCA), Datura stramonium agglutinin (DSA), erythroagglutinating phytohemagglutinin (E-PHA) and Sambucus nigra bark agglutinin (SNA). RESULTS: The binding ratios of ALP on L-PHA (22.94%+/-5.30%), DSA (55.97%+/-13.72%), LCA (38.16%+/-8.87%), E-PHA (11.56%+/-4.81%) and SNA (69.80%+/-13.71%) in HCC tissues were significantly increased (P<0.01) compared with that in normal liver tissues (L-PHA 5.89%+/-2.75%, DSA 36.20%+/-11.58%, LCA 17.90%+/-6.71%, E-PHA 5.38%+/-2.20%, SNA 57.32%+/-11.27%), respectively. t values between the two groups were 8.94, 3.64, 5.94, 3.62 and 2.32, respectively. L-PHA-binding ratio (25.84%+/-4.67%) of ALP in HCC with invasiveness was significantly higher than that (18.10%+/-3.64%) without invasiveness (t=3.71, P<0.01). CONCLUSION: The changes of ALP sugar chain structures occur in HCC tissue. b1-6 branching sugar chain structure of ALP is related to the invasiveness of HCC.

The preparation and characterization of monomethoxypoly(ethylene glycol)-b-poly-DL-lactide microcapsules containing bovine hemoglobin.

Methoxypoly(ethylene glycol)-b-poly-DL-lactide (PELA) microcapsules containing bovine hemoglobin (bHb) were prepared by a W/O/W double emulsion-solvent diffusion process. bHb solution was used as the internal aqueous phase, PELA/organic solvent as the oil phase, and polyvinyl alcohol (PVA) solution as the external aqueous phase. This W/O/W double emulsion was added into a large volume of water (solidification solution) to allow organic solvent to diffuse into water. The optimum preparative condition for PELA microcapsules loaded with bovine hemoglobin was investigated. It was found that homogenization rate, type of organic solvent, and volume of the solidification solution influenced the activity of bovine hemoglobin encapsulated. When the homogenization rate was lower than 9000 rpm and ethyl acetate was used as the organic solvent, there was no significant influence on the activity of hemoglobin. High homogenization rate as 12 000 rpm decreased the P50 and Hill coefficient. Increasing the volume of solidification solution had an effect of improving the activity of microencapsulated hemoglobin. The composition of the PELA had the most important influence on the success of encapsulation. Microcapsules fabricated by PELA with MPEG2k block (molecular weight of MPEG block: 2000) achieved a high entrapment efficiency of 90%, better than PL A homopolymer and PELA with MPEG5k blocks. Hemoglobin microcapsules with native loading oxygen activity (P50 = 26.0 mmHg, Hill coefficient = 2.4), mean size of about 10 microm, and high entrapment efficiency (ca. 93%) were obtained at the optimum condition.