Displaying publications 1 - 20 of 21 in total

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  1. Hyaluronic Acid-Based Bioconjugate Systems, Scaffolds, and Their Therapeutic Potential
    Kotla NG, Mohd Isa IL, Larrañaga A, Maddiboyina B, Swamy SK, Sivaraman G, et al.
    Adv Healthc Mater, 2023 Aug;12(20):e2203104.
    PMID: 36972409 DOI: 10.1002/adhm.202203104
    In recent years, the development of hyaluronic acid or hyaluronan (HA) based scaffolds, medical devices, bioconjugate systems have expanded into a broad range of research and clinical applications. Research findings over the last two decades suggest that the abundance of HA in most mammalian tissues with distinctive biological roles and chemical simplicity for modifications have made it an attractive material with a rapidly growing global market. Besides its use as native forms, HA has received much interest on so-called "HA-bioconjugates" and "modified-HA systems". In this review, the importance of chemical modifications of HA, underlying rationale approaches, and various advancements of bioconjugate derivatives with their potential physicochemical, and pharmacological advantages are summarized. This review also highlights the current and emerging HA-based conjugates of small molecules, macromolecules, crosslinked systems, and surface coating strategies with their biological implications, including their potentials and key challenges discussed in detail.
    Matched MeSH terms: Macromolecular Substances
  2. A decision tree model for the prediction of homodimer folding mechanism
    Suresh A, Karthikraja V, Lulu S, Kangueane U, Kangueane P
    Bioinformation, 2009 Nov 17;4(5):197-205.
    PMID: 20461159
    The formation of protein homodimer complexes for molecular catalysis and regulation is fascinating. The homodimer formation through 2S (2 state), 3SMI (3 state with monomer intermediate) and 3SDI (3 state with dimer intermediate) folding mechanism is known for 47 homodimer structures. Our dataset of forty-seven homodimers consists of twenty-eight 2S, twelve 3SMI and seven 3SDI. The dataset is characterized using monomer length, interface area and interface/total (I/T) residue ratio. It is found that 2S are often small in size with large I/T ratio and 3SDI are frequently large in size with small I/T ratio. Nonetheless, 3SMI have a mixture of these features. Hence, we used these parameters to develop a decision tree model. The decision tree model produced positive predictive values (PPV) of 72% for 2S, 58% for 3SMI and 57% for 3SDI in cross validation. Thus, the method finds application in assigning homodimers with folding mechanism.
    Matched MeSH terms: Macromolecular Substances
  3. Fulltext Synthesis and evaluation of a molecularly imprinted polymer for Pb(II) ion uptake
    Nor Azah Yusof, Beyan, Appri, Md. Haron Jelas, Nor Azowa Ibrahim
    Pertanika Journal of Science & Technology, 2009;17(1):-.
    MyJurnal
    A molecularly imprinted polymer (MIP), with the ability to bind Pb(II) ion, was prepared using the non-covalent molecular imprinting methods and evaluated as a sorbent for the Pb(II) ion uptake. 4-vinylbenzoic acid was chosen as the complexing monomer. The imprinted polymer was synthesized by radical polymerization. The template (Pb(II) ions) was removed using 0.1 M HCl. As a result, the efficient adsorption was found to occur at pH 7. The result also showed the applicability of the Langmuir model for the sorption, with the maximum sorption capacity of 204.08 μg/mg.
    Matched MeSH terms: Macromolecular Substances
  4. Recent Advances in Non-Invasive Delivery of Macromolecules using Nanoparticulate Carriers System
    Shadab M, Haque S, Sheshala R, Meng LW, Meka VS, Ali J
    Curr Pharm Des, 2017;23(3):440-453.
    PMID: 27784250 DOI: 10.2174/1381612822666161026163201
    BACKGROUND: The drug delivery of macromolecules such as proteins and peptides has become an important area of research and represents the fastest expanding share of the market for human medicines. The most common method for delivering macromolecules is parenterally. However parenteral administration of some therapeutic macromolecules has not been effective because of their rapid clearance from the body. As a result, most macromolecules are only therapeutically useful after multiple injections, which causes poor compliance and systemic side effects.

    METHOD: Therefore, there is a need to improve delivery of therapeutic macromolecules to enable non-invasive delivery routes, less frequent dosing through controlled-release drug delivery, and improved drug targeting to increase efficacy and reduce side effects.

    RESULT: Non-invasive administration routes such as intranasal, pulmonary, transdermal, ocular and oral delivery have been attempted intensively by formulating macromolecules into nanoparticulate carriers system such as polymeric and lipidic nanoparticles.

    CONCLUSION: This review discusses barriers to drug delivery and current formulation technologies to overcome the unfavorable properties of macromolecules via non-invasive delivery (mainly intranasal, pulmonary, transdermal oral and ocular) with a focus on nanoparticulate carrier systems. This review also provided a summary and discussion of recent data on non-invasive delivery of macromolecules using nanoparticulate formulations.

    Matched MeSH terms: Macromolecular Substances/chemistry
  5. Fulltext Conventional study on novel dicationic ionic liquid inclusion with β-cyclodextrin
    Mohamad S, Surikumaran H, Raoov M, Marimuthu T, Chandrasekaram K, Subramaniam P
    Int J Mol Sci, 2011;12(9):6329-45.
    PMID: 22016662 DOI: 10.3390/ijms12096329
    This study focuses on the synthesis and characterization of the inclusion complex of β-Cyclodextrin (β-CD) with dicationic ionic liquid, 3,3'-(1,4-Phenylenebis [methylene]) bis(1-methyl-1H-imidazol-3-ium) di(bromide) (PhenmimBr). The inclusion complex was prepared at room temperature utilizing conventional kneading technique. Proton ((1)H) NMR and 2D ((1)H-(1)H) COSY NMR were the primary characterization tools employed to verify the formation of the inclusion complex. COSY spectra showed strong correlations between protons of imidazolium and protons of β-CD which indicates that the imidazolium ring of PhenmimBr has entered the cavity of β-CD. UV absorption indicated that β-CD reacts with PhenmimBr to form a 2:1 β-CD-PhenmimBr complex with an apparent formation constant of 2.61 × 10(5) mol&(-2) L(2). Other characterization studies such as UV, FT-IR, XRD, TGA, DSC and SEM studies were also used to further support the formation of the β-CD-PhenmimBr inclusion complex.
    Matched MeSH terms: Macromolecular Substances/chemical synthesis; Macromolecular Substances/chemistry*
  6. Fulltext Data of microwave assisted extraction and conventional hot water extraction of Dendrobium Sonia 'Earsakul' orchid flower
    Netramai S, Kijchavengkul T, Samsudin H, Lertsiri S
    Data Brief, 2020 Aug;31:105906.
    PMID: 32637506 DOI: 10.1016/j.dib.2020.105906
    Crude extracts of fresh Dendrobium Sonia 'Earsakul' orchid flowers (DSE) were prepared using microwave assisted extraction (MAE; using household microwave oven) and hot water extraction (HWE; at constant 80 °C). The obtained DSEs were measured their absorbance at λmax of 543 and 583 nm and determined their total monomeric anthocyanin contents (TAC). Mathematical models of MAE of Dendrobium Sonia 'Earsakul' orchid flower were constructed using response surface methodology - Box-Behnken design. Studied parameters included flower to water ratio, microwave power, and extraction time, with absorbance at λmax as response. The data generated were 1) visible spectrum (400-700 nm) of DSE; 2) absorbance values at λmax and 3) TAC of DSEs obtained from various extraction conditions of MAE and HWE; 4) linear equations describing correlations between TAC and absorbance at λmax of DSEs; and 5) mathematical models of MAE of Dendrobium Sonia 'Earsakul' orchid.
    Matched MeSH terms: Macromolecular Substances
  7. Molecularly imprinted polymer synthesis using RAFT polymerisation
    Peter A.G. Cormack, Faizatul Shimal Mehamod
    Sains Malaysiana, 2013;42:529-535.
    In this paper, the synthesis and characterisation of caffeine-imprinted polymers are described. The polymers were prepared in monolithic form via both reversible addition-fragmentation chain-transfer (RAFT) polymerisation and conventional free radical polymerisation, using methacrylic acid and ethylene glycol dimethacrylate as the functional monomer and crosslinking agent, respectively. The potential benefits in applying RAFT polymerisation techniques towards the synthesis of molecularly imprinted polymers (MIPs) are explored and elucidated. The pore structures of the polymers produced were characterised by nitrogen sorption porosimetry and the molecular recognition properties of representative products were evaluated in high-performance liquid chromatography (HPLC) mode. Molecular imprinting effects were confirmed by analysing the relative retentions of analytes on imprinted and non-imprinted HPLC
    stationary phases. It was found that a caffeine-imprinted polymer synthesised by RAFT polymerisation was superior to a polymer prepared using a conventional synthetic approach; the imprinting factor and column efficiency were found to be higher for the former material.
    Matched MeSH terms: Macromolecular Substances
  8. Production of a bioflocculant from Aspergillus niger using palm oil mill effluent as carbon source
    Aljuboori AH, Uemura Y, Osman NB, Yusup S
    Bioresour Technol, 2014 Nov;171:66-70.
    PMID: 25189510 DOI: 10.1016/j.biortech.2014.08.038
    This study evaluated the potential of bioflocculant production from Aspergillus niger using palm oil mill effluent (POME) as carbon source. The bioflocculant named PM-5 produced by A. niger showed a good flocculating capability and flocculating rate of 76.8% to kaolin suspension could be achieved at 60 h of culture time. Glutamic acid was the most favorable nitrogen source for A. niger in bioflocculant production at pH 6 and temperature 35 °C. The chemical composition of purified PM-5 was mainly carbohydrate and protein with 66.8% and 31.4%, respectively. Results showed the novel bioflocculant (PM-5) had high potential to treat river water from colloids and 63% of turbidity removal with the present of Ca(2+) ion.
    Matched MeSH terms: Macromolecular Substances/metabolism*
  9. Controlled release compound based on metanilate-layered double hydroxide nanohybrid
    Hussein MZ, Nasir NM, Yahaya AH
    J Nanosci Nanotechnol, 2008 Nov;8(11):5921-8.
    PMID: 19198327
    Metanilate-layered double hydroxide nanohybrid compound was synthesized for controlled release purposes through co-precipitation method of the metal cations and organic anion. The effect of various divalent metal cations (M2+), namely Zn2+, Mg2+ and Ca2+ on the formation of metanilate-LDH nanohybrids, in which metanilate anion was intercalated into three different layered double hydroxide (LDH) systems; Zn-Al, Mg-Al and Ca-Al were investigated. The syntheses were carried out with M2+ to Al3+ initial molar ratio, R of 4. The pH of the mother liquor was maintained at pH 7.5 and 10 during the synthesis, and the resulting mixture was aged at around 70 degrees C for about 18 h. The intercalation of metanilate anion into the host was found to be strongly influenced by the M2+ that formed the inorganic metal hydroxide layers. Under our experimental condition, the formation of the nanohybrid materials was found to be more feasible for the Zn-Al than for the other two systems, in which the former showed well-ordered layered organic-inorganic nanohybrid structure with good crystallinity. Intercalation is confirmed by the expansion of the interlayer spacing to about 15-17 A when metanilate was introduced into the interlamellae of Zn-Al LDHs. In addition, CHNS and FTIR analyses also support that metanilate anion has been successfully intercalated into the interlamellae of the inorganic LDH. Apart from M2+, this study also shows that the initial pH of the mother liquor plays an important role in determining the physicochemical properties of the resulting nanohybrids, especially the mole fraction of the Zn2+ substituted by the Al3+ ion in the LDH inorganic sheets which in turn controlled the loading percentage of the organic anion, surface properties and the true density. Preliminary study shows that LDH can be used to host beneficial guests, active agent with controlled release capability of the guests. Generally the overall process is governed by pseudo second order kinetic but for the first 180 min, the release process can be slightly better described by parabolic diffusion than the other models.
    Matched MeSH terms: Macromolecular Substances/chemistry
  10. Synthesis and characterization of polymeric V2O5/AlO(OH) with nanopores on alumina support
    Ahmad AL, Abd Shukor SR, Leo CP
    J Nanosci Nanotechnol, 2006 Dec;6(12):3910-4.
    PMID: 17256351
    Polymeric vanadium pentoxide gel was formed via the reaction of V2O5 powder with hydrogen peroxide. The polymeric vanadium pentoxide gel was then dispersed in alumina gel. Different vanadium loading composites were coated on alumina support and calcined at 500 degrees C for 1 hr. These composite layers were characterized using TGA, FT-IR, XRD, SEM, and Autosorb. It was found that the lamellar structure of polymerized vanadium pentoxide was retained in the inorganic matrix. Crystalline alumina in gamma phase was formed after calcinations. However, the vanadium-alumina mixed oxides are lack of the well defined PXRD peaks for polycrystalline V2O5. This is possibly because the vanadia species are highly dispersed in the alumina matrix or the vanadia species are dispersed as crystalline which is smaller than 4 nm. In addition, the imbedded polymeric vanadium oxide improved the specific area and average pore diameter of the composite layer.
    Matched MeSH terms: Macromolecular Substances/chemistry
  11. A facile approach to prepare regenerated cellulose/graphene nanoplatelets nanocomposite using room-temperature ionic liquid
    Mahmoudian S, Wahit MU, Imran M, Ismail AF, Balakrishnan H
    J Nanosci Nanotechnol, 2012 Jul;12(7):5233-9.
    PMID: 22966551
    This study presents the preparation of regenerated cellulose (RC)/graphene nanoplatelets (GNPs) nanocomposites via room temperature ionic liquid, 1-ethyl-3-methylimidazolium acetate (EMIMAc) using solution casting method. The thermal stability, gas permeability, water absorption and mechanical properties of the films were studied. The synthesized nanocomposite films were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The T20 decomposition temperature of regenerated cellulose improved with the addition of graphene nanoplatelets up to 5 wt%. The tensile strength and Young's modulus of RC films improved by 34 and 56%, respectively with the addition of 3 wt% GNPs. The nanocomposite films exhibited improved oxygen and carbon dioxide gas barrier properties and water absorption resistance compared to RC. XRD and SEM results showed good interaction between RC and GNPs and well dispersion of graphene nanoplatelets in regenerated cellulose. The FTIR spectra showed that the addition of GNPs in RC did not result in any noticeable change in its chemical structure.
    Matched MeSH terms: Macromolecular Substances/chemistry
  12. Substrate effects on surface morphologies and magnetic properties of nanostructured FePt thin films
    Low PL, Yong BE, Ong BH, Matsumoto M, Tou TY
    J Nanosci Nanotechnol, 2011 Mar;11(3):2640-3.
    PMID: 21449444
    The substrate effects on surface morphologies, crystal structures, and magnetic properties of the sputter-deposited FePt thin films on Corning 1737, normal glass, and Si wafer substrates, respectively, were investigated. High in-plane coercivities of 10 kOe were obtained for the air-annealed films on Corning 1737 and Si wafer, where both films similarly have granular-like morphologies. Besides, increasing grain size and surface roughness of all the FePt films with the post-anneal temperature were observed. Moreover, partially separated grains were seen in the film on Si wafer, where the formation of Fe silicides during post-anneal is suspected, in which has enhanced the magnetic ordering.
    Matched MeSH terms: Macromolecular Substances/chemistry
  13. Observation of a cubical-like microstructure of strontium iron garnet and yttrium iron garnet prepared via sol-gel technique
    Nasir N, Yahya N, Kashif M, Daud H, Akhtar MN, Zaid HM, et al.
    J Nanosci Nanotechnol, 2011 Mar;11(3):2551-4.
    PMID: 21449424
    This is our initial response towards preparation of nano-inductors garnet for high operating frequencies strontium iron garnet (Sr3Fe5O12) denoted as SrIG and yttrium iron garnet (Y3Fe5O12) denoted as YIG. The garnet nano crystals were prepared by novel sol-gel technique. The phase and crystal structure of the prepared samples were identified by using X-ray diffraction analysis. SEM images were done to reveal the surface morphology of the samples. Raman spectra was taken for yttrium iron garnet (Y3Fe5O12). The magnetic properties of the samples namely initial permeability (micro), relative loss factor (RLF) and quality factor (Q-Factor) were done by using LCR meter. From the XRD profile, both of the Y3Fe5O12 and Sr3Fe5O12 samples showed single phase garnet and crystallization had completely occurred at 900 degrees C for the SrIG and 950 degrees C for the YIG samples. The YIG sample showed extremely low RLF value (0.0082) and high density 4.623 g/cm3. Interesting however is the high Q factor (20-60) shown by the Sr3Fe5O12 sample from 20-100 MHz. This high performance magnetic property is attributed to the homogenous and cubical-like microstructure. The YIG particles were used as magnetic feeder for EM transmitter. It was observed that YIG magnetic feeder with the EM transmitter gave 39% higher magnetic field than without YIG magnetic feeder.
    Matched MeSH terms: Macromolecular Substances/chemistry
  14. Biosynthesis and mobilization of poly(3-hydroxybutyrate) [P(3HB)] by Spirulina platensis
    Jau MH, Yew SP, Toh PS, Chong AS, Chu WL, Phang SM, et al.
    Int J Biol Macromol, 2005 Aug;36(3):144-51.
    PMID: 16005060
    Three strains of Spirulina platensis isolated from different locations showed capability of synthesizing poly(3-hydroxybutyrate) [P(3HB)] under nitrogen-starved conditions with a maximum accumulation of up to 10 wt.% of the cell dry weight (CDW) under mixotrophic culture conditions. Intracellular degradation (mobilization) of P(3HB) granules by S. platensis was initiated by the restoration of nitrogen source. This mobilization process was affected by both illumination and culture pH. The mobilization of P(3HB) was better under illumination (80% degradation) than in dark conditions (40% degradation) over a period of 4 days. Alkaline conditions (pH 10-11) were optimal for both biosynthesis and mobilization of P(3HB) at which 90% of the accumulated P(3HB) was mobilized. Transmission electron microscopy (TEM) revealed that the mobilization of P(3HB) involved changes in granule quantity and morphology. The P(3HB) granules became irregular in shape and the boundary region was less defined. In contrast to bacteria, in S. platensis the intracellular mobilization of P(3HB) seems to be faster than the biosynthesis process. This is because in cyanobacteria chlorosis delays the P(3HB) accumulation process.
    Matched MeSH terms: Macromolecular Substances/chemistry
  15. Studies on the interaction of mononuclear metal(II) complexes of amino‑naphthoquinone with bio-macromolecules
    Kosiha A, Lo KM, Parthiban C, Elango KP
    Mater Sci Eng C Mater Biol Appl, 2019 Jan 01;94:778-787.
    PMID: 30423764 DOI: 10.1016/j.msec.2018.10.021
    Three metal(II) complexes [CoLCl2], [CuLCl2] and [ZnL2Cl2] {L = 2‑chloro‑3‑((3‑dimethylamino)propylamino)naphthalene‑1,4‑dione} have been synthesized and characterized using analytical, thermal and spectral techniques (FT-IR, UV-Vis, ESR and ESI-MS). The structure of the L has been confirmed by single crystal XRD study. The complexes show good binding propensity to bovine serum albumin (BSA) having relatively higher binding constant values (104 M-1) than the ligand. Fluorescence spectral studies indicate that [CoLCl2] binds relatively stronger with CT DNA through intercalative mode, exhibiting higher binding constant (2.22 × 105 M-1). Agarose gel electrophoresis run on plasmid DNA (pUC18) prove that all the complexes showed efficient DNA cleavage via hydroxyl radical mechanism. The complexes were identified as potent anticancer agents against two human cancer cell lines (MCF7 and A549) by comparing with cisplatin. Co(II) complex demonstrated greater cytotoxicity against MCF7 and A549 cells with IC50 values at 19 and 22 μM, respectively.
    Matched MeSH terms: Macromolecular Substances/chemistry*
  16. Dynamics of PEGylated-dextran-spermine nanoparticles for gene delivery to leukemic cells
    Amini R, Jalilian FA, Abdullah S, Veerakumarasivam A, Hosseinkhani H, Abdulamir AS, et al.
    Appl Biochem Biotechnol, 2013 Jun;170(4):841-53.
    PMID: 23615733 DOI: 10.1007/s12010-013-0224-0
    Leukemic cells are hard-to-transfect cell lines. Many transfection reagents which can provide high gene transfer efficiency in common adherent cell lines are not effective to transfect established blood cell lines or primary leukemic cells. This study aims to examine a new class of cationic polymer non-viral vector, PEGylated-dextran-spermine (PEG-D-SPM), to determine its ability to transfect the leukemic cells. Here, the optimal conditions of the complex preparation (PEG-D-SPM/plasmid DNA (pDNA)) were examined. Different weight-mixing (w/w) ratios of PEG-D-SPM/pDNA complex were prepared to obtain an ideal mixing ratio to protect encapsulated pDNA from DNase degradation and to determine the optimal transfection efficiency of the complex. Strong complexation between polymer and pDNA in agarose gel electrophoresis and protection of pDNA from DNase were detected at ratios from 25 to 15. Highest gene expression was detected at w/w ratio of 18 in HL60 and K562 cells. However, gene expression from both leukemic cell lines was lower than the control MCF-7 cells. The cytotoxicity of PEG-D-SPM/pDNA complex at the most optimal mixing ratios was tested in HL60 and K562 cells using MTS assay and the results showed that the PEG-D-SPM/pDNA complex had no cytotoxic effect on these cell lines. Spherical shape and nano-nature of PEG-D-SPM/pDNA complex at ratio 18 was observed using transmission electron microscopy. As PEG-D-SPM showed modest transfection efficiency in the leukemic cell lines, we conclude that further work is needed to improve the delivery efficiency of the PEG-D-SPM.
    Matched MeSH terms: Macromolecular Substances/chemistry
  17. Molecularly imprinted polymer for the removal of diclofenac from water: Synthesis and characterization
    Samah NA, Sánchez-Martín MJ, Sebastián RM, Valiente M, López-Mesas M
    Sci Total Environ, 2018 Aug 01;631-632:1534-1543.
    PMID: 29727977 DOI: 10.1016/j.scitotenv.2018.03.087
    Contaminants of Emerging Concerns (CECs) have been introduced as one type of recalcitrant pollutant sources in water. In this study, the non-steroidal anti-inflammatory drug diclofenac (DCF) has been removed from water solutions using Molecularly Imprinted Polymer (MIP), synthetized via bulk polymerization with allylthiourea (AT) as the functional monomer and using DCF as template (MIP-DCF). DCF detection has been performed by UV spectrophotometer. From the kinetic study in batch mode, approximately 100% of removal is observed by using 10mg of MIP-DCF, with an initial concentration of 5mg/L of DCF at pH7, within 3min and agitated at 25°C. In continuous flow mode study, using a cartridge pre-packed with 10mg of MIP-DCF, a high adsorption capacity of 160mgDCF/g MIP was obtained. To study the porosity of MIPs, scanning electron microscopy (SEM) has been used. In order to characterize the chemical interaction between monomer and template, the pre-polymerization mixture for MIP and DCF has also been studied by 1H NMR. One of the chemical shift observed has been related to the formation of a complex between amine protons of thiourea group of AT with carboxylic acid on DCF. In conclusion, the developed MIP works as a good adsorbent for DCF removal, and is selective to DCF in the presence of indomethacin and ibuprofen.
    Matched MeSH terms: Macromolecular Substances
  18. Structure-property interpretation of biological polyhydroxyalkanoates with different monomeric composition: Dielectric spectroscopy investigation
    Ishak KA, Velayutham TS, Annuar MSM, Sirajudeen AAO
    Int J Biol Macromol, 2021 Feb 01;169:311-320.
    PMID: 33340632 DOI: 10.1016/j.ijbiomac.2020.12.090
    Dielectric spectroscopy is employed to study the relaxation phenomena in natural polyhydroxyalkanoates (PHAs) upon temperature and frequency variations. Effects of PHAs molecular structure on the relaxation, arising from the differences in monomeric composition, are investigated under identical conditions in a frequency range of 10-2-106 Hz, and at different temperatures. All PHA samples showed different dielectric response at different temperature. Primary α-relaxation signals are observed at temperature corresponding to the glass transition temperature. On the other hand, secondary β- and γ-relaxations are detected at low temperatures, and attributed to local motions of polar groups and small segments of the polymer chain. The dielectric properties of representative PHA samples are compared and discussed.
    Matched MeSH terms: Macromolecular Substances
  19. Fulltext Gene transfer into the lung by nanoparticle dextran-spermine/plasmid DNA complexes
    Abdullah S, Wendy-Yeo WY, Hosseinkhani H, Hosseinkhani M, Masrawa E, Ramasamy R, et al.
    J Biomed Biotechnol, 2010;2010:284840.
    PMID: 20617146 DOI: 10.1155/2010/284840
    A novel cationic polymer, dextran-spermine (D-SPM), has been found to mediate gene expression in a wide variety of cell lines and in vivo through systemic delivery. Here, we extended the observations by determining the optimal conditions for gene expression of D-SPM/plasmid DNA (D-SPM/pDNA) in cell lines and in the lungs of BALB/c mice via instillation delivery. In vitro studies showed that D-SPM could partially protect pDNA from degradation by nuclease and exhibited optimal gene transfer efficiency at D-SPM to pDNA weight-mixing ratio of 12. In the lungs of mice, the levels of gene expression generated by D-SPM/pDNA are highly dependent on the weight-mixing ratio of D-SPM to pDNA, amount of pDNA in the complex, and the assay time postdelivery. Readministration of the complex at day 1 following the first dosing showed no significant effect on the retention and duration of gene expression. The study also showed that there was a clear trend of increasing size of the complexes as the amount of pDNA was increased, where the sizes of the D-SPM/pDNA complexes were within the nanometer range.
    Matched MeSH terms: Macromolecular Substances
  20. Nucleotide changes responsible for loss of neuroinvasiveness in Japanese encephalitis virus neutralization-resistant mutants
    Cecilia D, Gould EA
    Virology, 1991 Mar;181(1):70-7.
    PMID: 1704661
    The Sarawak strain of Japanese encephalitis virus (JE-Sar) is virulent in 3-week-old mice when inoculated intraperitoneally. The nucleotide sequence for the envelope glycoprotein (E) of this virus was determined and compared with the published sequences of four other strains. There were several silent nucleotide differences and five codon changes. Monoclonal antibodies (MAbs) against the E protein of JE-Sar virus were prepared and characterized. MAb-resistant mutants of JE-Sar were selected to determine if mutations in the E protein gene could affect its virulence for mice. Eight mutants were isolated using five different MAbs that identified virus-specific or group-reactive epitopes on the E protein. The mutants lost either complete or partial reactivity with selecting MAb. Several showed decreased virulence in 3-week-old mice after intraperitoneal inoculation. Two (r27 and r30) also showed reduced virulence in 2-week-old mice. JE-Sar and the derived mutants were comparable in their virulence for mice, when inoculated intracranially. Mutant r30 but not r27 induced protective immunity in adult mice against intracranial challenge with parent virus. However, r27-2 did induce protective immunity against itself. Nucleotide sequencing of the E coding region for the mutants revealed single base changes in both r30 and r27 resulting in a predicted change from isoleucine to serine at position 270 in r30 and from glycine to aspartic acid at position 333 in r27. The altered capacity of the mutants to induce protective immunity is consistent with the immunogenicity changes predicted by computer analysis using the Protean II program.
    Matched MeSH terms: Macromolecular Substances
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