Lack Of Aggregation Research Articles

Disrupted Market Relations in Agriculture in North Macedonia: the COVID-19 Crisis

Abstract The COVID-19 crisis has stressed the importance of, and need for, a stable and functional food system, able to provide consumers with a continuous supply of quality food at affordable prices. The pandemic has also highlighted the role of agricultural producers in the food supply chain, with small farmers being the most vulnerable category. This global crisis has actually deepened the problems faced by farmers, especially those on the verge of sustainability. The purpose of this analysis was to provide an overview of the disrupted links in agriculture, as a result of the initial COVID-19 crisis. A survey was carried out with 91 farmers in North Macedonia. Moreover, in-depth interviews were conducted with selected traders and processors. In general, farmers assessed that the crisis negatively affected their economic operations. The critical parts of the supply chain derive from the disrupted link between farmers and traders/processors, lack of field technical support resulting from the mobility restrictions, uncertainty in cooperation, lower production quantities, and varying quality of the agricultural products. Availability and cost of seasonal workforce was also pronounced as an issue. The dominant family farms small-scale structure and lack of aggregation in the sector challenged the resilience and effective response to the crisis. From buyers’ and processors’ perspective, the crisis effect was marked through the disrupted communication with farmers, low awareness of the need for change, and drastic decline in the HORECA channel sales. The agricultural and rural policy is designed to address measures adjusted to the needs of the key actors in the sector. The priority set of measures should support the food supply chain, enhancing farmers’ networking and aggregation, and on-farm and off-farm diversification, along with improved communication, information systems and digitalisation. Improving productivity and competitiveness remains an effective strategy for sustainable operations, greater resilience and risk adaptation in crises such as the pandemic.

A Dictyostelium model for BPAN disease reveals a functional relationship between the WDR45/WIPI4 homolog Wdr45l and Vmp1 in the regulation of autophagy-associated PtdIns3P and ER stress

ABSTRACT PROPPINs are conserved PtdIns3P-binding proteins required for autophagosome biogenesis that fold into a characteristic group of seven-bladed beta-propellers. Mutations in WDR45/WIPI4, a human member of this family, lead to BPAN, a rare form of neurodegeneration. We have generated mutants for the two PROPPIN proteins present in the model system Dictyostelium discoideum (Atg18 and Wdr45l) and characterized their function. Lack of Wdr45l greatly impairs autophagy, while Atg18 only causes subtle defects in the maturation of autolysosomes. The strong phenotype of the Wdr45l mutant is strikingly similar to that observed in Dictyostelium cells lacking Vmp1, an ER protein required for omegasome formation. Common phenotypes include impaired growth in axenic medium, lack of aggregation, and local enrichment of PtdIns3P as determined by the use of lipid reporters. In addition, Vmp1 and Wdr45l mutants show a chronically active response to ER stress. For both mutants, this altered PtdIns3P localization can be prevented by the additional mutation of the upstream regulator Atg1, which also leads to recovery of axenic growth and reduction of ER stress. We propose that, in addition to an autophagy defect, local autophagy-associated PtdIns3P accumulation might contribute to the pathogenesis of BPAN by disrupting ER homeostasis. The introduction of BPAN-associated mutations in Dictyostelium Wdr45l reveals the impact of pathogenic residues on the function and localization of the protein.

QCM nanocomposite gas sensors – Expanding the application of waterborne polymer composites based on graphene nanoribbon

Graphene nanoribbons (GNR) are narrow strips of graphene in one dimensional morphology with extraordinary properties, owing to the large edges that offer numerous interfacial contact area to the polymer phase in the composite materials. Consequently, minor amount of GNR incorporated within polymer matrix, will not only reinforced mechanically and thermally the composite materials, but will significantly expand their application potential, giving added value to the cheap polymeric material. Herein, the quartz crystal microbalance (QCM) gas sensing of the nanocomposites was investigated.In this work we took advantage of the polymerization in dispersed media as green synthesis method to produce for first time waterborne polymer/GNR nanocomposites. The lack of aggregation during structuring of GNRs within the polymer matrix and the established covalent bonding between the polymer and GNRs phases were responsible for the observed strong mechanical and thermal reinforcement of the nanocomposites. By exposure of the nanocomposites to low concentrations of toxic gases (CO, NH3, and N2O in a concentration range of 70–1000 ppm), it was found that the sensors are characterized by a large sensor response in short time, at room temperature and with very good reproducibility in three investigated cycles of gas adsorption and desorption. The excellent performance was attributed to the large functional interface created between the GNRs and the polymer that offer numerous adsorption sites, along with the composite morphology that provide availability of these sites to the gasses. The sensors have shown selectivity towards NH3 rather than N2O and CO, likely, because the former interacted with the composite materials by joint Wan der Waals forces and hydrogen bonding, whereas the last two gasses interact exclusively by the van der Waals interactions.

The relationship between state funding and volunteer levels in voluntary sector organisations: a quantitative analysis of regulatory data

There is a long-standing debate within voluntary sector studies concerning the relationship between state funding and volunteer levels within voluntary sector organisations (VSOs). Due to a lack of suitable data, this debate has previously suffered from a lack of aggregate, quantitative evidence at the sector level. This article helps to fill this gap by exploring the relationship among larger charities in England and Wales (those with an annual income over £500,000), using a relatively new regulatory dataset on charity funding sources. The findings reveal a complicated relationship, with some small to moderate associations between the key variables. Among VSOs with at least some state funding, state income is correlated with smaller proportions of volunteers, even after controlling for size and industry. However, those with no state funding at all appear less likely to use volunteers, and to use them in lower average numbers, than those with at least some state income.

Trials and tribulations of coronavirus disease-2019 research: with a few bright lights in the fog.

Trials and tribulations of coronavirus disease-2019 research: with a few bright lights in the fog.

Epidemiology, Predisposing Factors, Biomarkers, and Prevention Mechanism of Obesity: A Systematic Review.

Background. Globally, obesity is becoming a public health problem in the general population. Various determinants were reported by different scholars even though there are inconsistencies. Different biomarkers of obesity were identified for the prediction of obesity. Even though researchers speculate the factors, biomarkers, consequences, and prevention mechanisms, there is a lack of aggregate and purified data in the area of obesity. Summary. In this review, the epidemiology, predisposing factors, biomarkers, consequences, and prevention approaches of obesity were reviewed. Key Messages. The epidemiology of obesity increased in low-, middle-, and high-income countries. Even if the factors vary across regions and socioeconomic levels, sociodemographic, behavioral, and genetic factors were prominent for the development of obesity. There are a lot of biomarkers for obesity, of which microRNA, adipocytes, oxidative stress, blood cell profile, nutrients, and microbiota were promising biomarkers for determination of occurrence of obesity. Since the consequences of obesity are vast and interrelated, multidimensional prevention strategy is mandatory in all nations.

Sedimentation Velocity Analytical Ultracentrifugation of Oxidized Recombinant Full-Length Factor VIII.

Anti-drug antibodies to coagulation factor VIII (fVIII), often termed inhibitors, present the greatest economical and treatment related obstacle in the management of hemophilia A. Although several genetic and environmental risk factors associated with inhibitor development have been identified, the precise mechanisms responsible for the immune response to exogenous fVIII therapies remain undefined. Clinical trials suggest there is an increased immunogenic potential of recombinant fVIII compared to plasma-derived products. Additional biochemical and immunological studies have demonstrated that changes in recombinant fVIII production and formulation can alter fVIII structure and immunogenicity. Recently, one study demonstrated increased immunogenicity of the recombinant fVIII product Helixate in hemophilia A mice following oxidation with hypochlorite (ClO−). It is widely reported that protein aggregates within drug products can induce adverse immune reactions in patients. Several studies have therefore investigated the prevalence of molecular aggregates in commercial recombinant products with and without use-relevant stress and agitation. To investigate the potential link between oxidation-induced immunogenicity and molecular aggregation, we analyzed the recombinant fVIII product, Helixate, via sedimentation velocity analytical ultracentrifugation following oxidation with ClO−. At 80 μM ClO−, a concentration that reduced the specific-activity by 67%, no detectable increase in large molecular aggregates (s > 12 S) was observed when compared to non-oxidized fVIII. This lack of aggregates was demonstrated both in commercial excipient as well as a HEPES buffered saline formulation. These data suggest that oxidation induced immunogenicity is independent of aggregate-mediated immune response. Therefore, our data support multiple, independent mechanisms underlying fVIII immunogenicity.

A Platinum Functional Porphyrin Conjugate: An Excellent Cancer Killer for Photodynamic Therapy

Abstract A novel tetracationic porphyrin-platinum(II) conjugate was synthesized and characterized. This complex, 4Pt(dach)ClTPyP, showed reasonable water solubility, lack of aggregation, and high singlet oxygen quantum yield. It also exhibited low dark cytotoxicity and excellent photocytotoxicity (Colon26: 0.17 µM; Sarcoma180: 0.25 µM). The mechanisms of cell death have been investigated and are attributed to high singlet oxygen generation, internalization into nucleus, and a caspase-3 induced apoptosis pathway. In the in vivo photodynamic therapy (PDT) assay, 4Pt(dach)ClTPyP completely killed tumor tissue, not simply displaying inhibition of tumor growth, and no recurrence was seen 18 days later after a single administration. All these findings of 4Pt(dach)ClTPyP shed light on a potential clinical use for cancer PDT in the future.

Incorporation of hydroxyproline in bacterial collagen from Streptococcus pyogenes

Bacterial collagen-like proteins differ from vertebrate collagens in that they do not contain hydroxyproline, which is seen as a characteristic of the vertebrate collagens, and which provides a significant contribution to the stability of the collagen triple-helix at body temperature. Despite this difference, the bacterial collagens are stable at around body temperature through inclusion of other stabilising sequence elements. Another difference is the lack of aggregation, and certain vertebrate collagen binding domains that can be introduced into the bacterial sequence lack full function when hydroxyproline is absent. In the present study we have demonstrated that a simple method utilising co-translational incorporation during fermentation can be used to incorporate hydroxyproline into the recombinant bacterial collagen. The presence and amount of hydroxyproline incorporation was shown by amino acid analysis and by mass spectrometry. A small increase in thermal stability was observed using circular dichroism spectroscopy. Statement of SignificanceRecombinant bacterial collagens provide a new opportunity for biomedical materials as they are readily produced in large quantity in E. coli. Unlike animal collagens, they are stable without the need for inclusion of a secondary modification system for hydroxyproline incorporation. In animal collagens, however, introduction of hydroxyproline is essential for stability and is also important for functional molecular interactions within the mammalian extracellular matrix. The present study has shown that hydroxyproline can be readily introduced into recombinant S. pyogenes bacterial collagen through direct co-translational incorporation of this modified imino acid during expression using the codons for proline in the introduced gene construct. This hydroxylation further improves the stability of the collagen and is available to enhance any introduced molecular functions.

Glanzmann Thrombasthenia: A Case Report in Moroccan Child

Glanzmann thrombasthenia is a hereditary hemorrhagic problem and is characterized by a qualitative or quantitative deficiency of the platelet glycoprotein GPIIb-IIIa, responsible for the reduction of platelet aggregation. The reported case concerns an 11-year-old child admitted to the Clinical Hematology Department of the University Hospital Mohamed 6 for epistaxis and gingivorrhagia. The questioning of the father revealed the concept of consanguinity, as well as his history of death and his hemorrhagic syndrome. The biological assessment performed in a patient shows a normal blood count; it is not particularly thrombocytopenia and the platelets have an average volume of 10.6 fL, the prothrombin time (PT), the partial thromboplastin time with activator (APTT) are normal. The platelet occlusion time (POT) is lengthened. The von Willebrand factor has not been investigated: the antigen (VWF-Ag) is 148% and the cofactor of ristocetin (VWF-RCo) is 116%. On the other hand, the exploration of platelet functions shows a lack of aggregation or of the platelet activator used: there is no aggregation in the presence of collagen, ADP, acid arachidonic, and aggregation induced by ristocetin is very disturbed. Immunophenotyping of platelet glycoproteins and the study of glycoprotein expression after thrombin activation by flow cytometry resulting from GpIIbIIIa (CD41), GpIIIa (CD61). The diagnosis is available for this patient is Glanzmann trombasthenia.

OR47 A novel role for antibodies to HLA and self-antigens: Induction of immuno-stimulatory exosomes

Aim Recent report from us demonstrated that lung transplant recipients who developed donor specific antibodies (DSA) against HLA and chronic rejection (Bronchiolitis Obliterans Syndrome (BOS)) had circulating exosomes expressing donor HLA and lung self-antigens (SAgs), Collagen-V and K α 1-Tubulin, (AJT,17:474,2017). The goals of this study are to determine the role of DSA and antibodies (Abs) to SAgs in the development of exosomes and to define their immunogenicity. Methods Towards determining exosome development following ligation of antigens by Abs, an in vitro assay using human airway epithelial cells (AEC) incubated with allo-Abs to HLA (high panel reactive antibody sera) or Abs to lung SAgs was performed. After incubating AEC for 24 h, supernatants were collected for exosome isolation. Exosomes were isolated by ultracentrifugation and lack of aggregates determined using sucrose density gradient. Presence of exosome marker CD-9 and Alix, SAgs, costimulatory molecules (CD-80 & 86), HLA-class II and 20 s proteasome subunit α 3 were determined by immunoblot. Exosomes isolated from BOS patients were used for immunization of mice with or without adjuvants and immune responses determined, Abs by ELISA and SAg specific cytokines by ELISpot. Results Culture of AEC with either anti-HLA or Abs to SAgs, but not control, resulted in exosome secretion to the supernatant. Cells remained viable (>90%) at 24hrs when supernatant was collected for exosome isolation. Exosomes demonstrated markers CD-9 and Alix, lung SAgs, costimulatory molecules (CD80 & 86), HLA-class II and 20S proteasome. Immunization of mice with exosomes from BOS patients with or without adjuvant resulted in Abs to K α 1-Tubulin and Collagen-V. Splenic T cells responded to both SAgs with increased frequencies of IFN-’Y and IL17 with reduction in IL10. Conclusions Ligation of AEC by anti-HLA or anti-lung SAgs results in exosome development without cell death. Exosomes contain lung SAgs along with HLA-class II, 20S proteasome and costimulatory molecules making it highly immunogenic. Therefore, exosomes released from AEC upon binding by either de novo developed DSA or Abs to lung SAgs will augment immune responses following lung transplantation leading to rejection.

Covalent-Bonded Reduced Graphene Oxide-Fluorescein Complex as a Substrate for Extrinsic SERS Measurements.

When graphene is used as SERS substrates, it contributes to the chemical mechanism (CM) of enhancement of Raman signal, owing to which the detection limit is very low (lower than mM content of probe molecules). The CM of enhancement depends largely on the interactions between the substrate and the probe molecules. Therefore, in this work, we have investigated the possibility of increasing the SERS activity of graphene by improving the interaction between the probe molecule and the graphene substrate by establishing exclusively strong covalent bonding between them. Fluorescein (Fl) was selected as a probe molecule because it is one of the most commonly used fluorophore in bioscience. As a graphene substrate, reduced graphene oxide (rGO) platelets were used. In addition, silver nanoparticles (AgNPs) were added onto the hybrids to further increase the enhancement by electromagnetic mechanism. Highly enhanced Raman signal of Fl onto neat rGO was achieved for micromolar concentration of the probe molecules. This was attributed to the covalent bonding between them, which introduced hole doping to rGO, decreasing the Fermi level of rGO and bringing it more closely to the LUMO of Fl. This induces aligning of their energy levels, resulting in higher contribution of the nonresonance effect to the charge transfer mechanism of enhancement, which, in this case, occurred intramolecularly. When AgNPs were added onto the rGO substrate, the expected enhancement performance was not observed. On the one hand, this was attributed to small size (∼20 nm) of AgNPs and lack of aggregates and, on the other, due to the unusually high contribution of CM determined.

Design of polymeric core-shell nanocontainers impregnated with benzotriazole for active corrosion protection of galvanized steel

Abstract Polymeric nanocontainers (NCs) impregnated with corrosion inhibitor benzotriazole are formed using layer-by-layer deposition of poly(acrylic acid) and poly(diallyldimethylammonium chloride) onto hematite particles in the presence of 0.1 M NaCl. Electric light scattering and electrophoresis are employed to control the formation and the size of NCs, as well as the stability of their suspensions. The inhibitor loaded NCs are incorporated into the volume of the galvanized coating during the electrodeposition of zinc on the steel substrate to ensure additional self-healing effect in the case of corrosion attack. The surface morphology and the uniformity of this composite coating as well as the lack of aggregation of the nanocontainers is demonstrated by scanning electron microscopy. The influence of NCs present in the zinc electrolyte on the cathodic and anodic processes is investigated by cyclic voltammetry. The corrosion behavior of the composite coatings at conditions of external cathodic and anodic polarization is tested with potentiodynamic measurements and the results are compared to pure zinc coatings. The composite coatings with embedded NCs revealed enhanced corrosion protection of low carbon steel in comparison with the pure zinc coatings in neutral corrosion medium.

A modularized framework for sales and operations planning with focus on process industries

This paper suggests a modularized sales and operations planning (S&OP) framework, consisting of content and process. The framework’s content is based on a typology of decoupling points in which the effect of decoupling points on the decision variables in S&OP is studied. The framework’s process takes a step back and addresses the need for a more elaborate design to precede the operational use of S&OP content for different production contexts. The framework supports both process industries (PIs) and discrete manufacturing industries (DIs), and recognizes their specific requirements and reflects them in their S&OP. The differentiating characteristics of PIs and DIs are emphasized through three different decoupling points, namely: discretization decoupling point, control mode decoupling point, and customer order decoupling point. The suggested framework aims to fill the gap in the literature regarding the lack of aggregate planning processes that match the PIs’ specific requirements by reflecting the differentiating characteristics of PIs in S&OP.

Ecology and application of haloalkaliphilic anaerobic microbial communities.

Haloalkaliphilic microorganisms that grow optimally at high-pH and high-salinity conditions can be found in natural environments such as soda lakes. These globally spread lakes harbour interesting anaerobic microorganisms that have the potential of being applied in existing technologies or create new opportunities. In this review, we discuss the potential application of haloalkaliphilic anaerobic microbial communities in the fermentation of lignocellulosic feedstocks material subjected to an alkaline pre-treatment, methane production and sulfur removal technology. Also, the general advantages of operation at haloalkaline conditions, such as low volatile fatty acid and sulfide toxicity, are addressed. Finally, an outlook into the main challenges like ammonia toxicity and lack of aggregation is provided.

Preparation and pharmacodynamic assessment of ezetimibe nanocrystals: Effect of P-gp inhibitory stabilizer on particle size and oral absorption

Drug nanocrystals have been widely accepted as potent formulations to overcome poor solubility, dissolution and bioavailability problems of hydrophobic drugs. The present study aimed to develop drug nanocrystals of ezetimibe (Eze), a model BCS class II and hypocholesterolemic drug using bottom up precipitation methods. d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS), and l-ascorbic acid-2-glucoside (AA2G), were the two stabilizers whose potential in developing Eze nanocrystals was investigated. Particle size and zeta potential portrayed the potential of both the stabilizers in producing Eze nanocrystals. The optimized nanocrystal formulations were evaluated for in-vitro solubility, dissolution, solid state characters and in-vivo pharmacodynamic performance. The nanocrystal formulations remarkably increased the solubility of the drug (p<0.05 compared to pure drug). Pure drug could not dissolve more than 28.9% during the 60min dissolution study whereas the drug nanocrystals prepared with AA2G and TPGS presented t90% at 41.33±2.58 and 16.07±2.32min, respectively. The PXRD and DSC studies confirmed the retention of crystallinity and the SEM images indicated lack of aggregation in dried nanocrystals. The TPGS nanocrystals presented significantly superior pharmacodynamic activity upon oral administration. The current study corroborated TPGS nanocrystals to be a promising choice of formulation for the oral delivery of Eze.

Spatio-temporal variability in the distribution of ground-dwelling riparian spiders and their potential role in water-to-land energy transfer along Hong Kong forest streams.

Terrestrial predators have been shown to aggregate along stream margins during periods when the emergence of adult aquatic insects is high. Such aggregation may be especially evident when terrestrial surroundings are relatively unproductive, and there are steep productivity gradients across riparia. In tropical forests, however, the productivity of inland terrestrial habitats may decrease the resource gradient across riparia, thus lessening any tendency of terrestrial predators to aggregate along stream margins. We elucidated the spatio-temporal variability in the distribution of ground-dwelling spiders and terrestrial arthropod prey within the riparia of two forest streams in tropical Hong Kong by sampling arthropods along transects at different distances from the streams during the wet and dry seasons. Environmental variables that may have influenced spider distributions were also measured. The vast majority of ground-dwelling predators along all transects at both sites were spiders. Of the three most abundant spiders captured along stream margins, Heteropoda venatoria (Sparassidae) and Draconarius spp. (Agelenidae) were terrestrially inclined and abundant during both seasons. Only Pardosa sumatrana (Lycosidae) showed some degree of aggregation at the stream banks, indicating a potential reliance on aquatic insect prey. Circumstantial evidence supports this notion, as P. sumatrana was virtually absent during the dry season when aquatic insect emergence was low. In general, forest-stream riparia in Hong Kong did not appear to be feeding hotspots for ground-dwelling predators. The lack of aggregation in ground-dwelling spiders in general may be attributed to the low rates of emergence of aquatic insects from the study streams compared to counterpart systems, as well as the potentially high availability of terrestrial insect prey in the surrounding forest. Heteropoda venatoria, the largest of the three spiders maintained a high biomass (up to 28 mg dry weight/m2) in stream riparia, exceeding the total standing stock of all other spiders by 2–80 times. The biomass and inland distribution of H. venatoria could make it a likely conduit for the stream-to-land transfer of energy.

Copolymerization and Synthesis of Multiply Binding Histamine Ligands for the Robust Functionalization of Quantum Dots

The polymeric functionalization of quantum dots via ligand exchange is a robust method for the preparation of stable fluorescent particles with high quantum yields. For most biological applications of quantum dots, water solubility is a key requirement; to achieve biocompatibility, polymeric ligand systems that can provide water solubility as well as effective anchoring groups are advantageous. In this work, histamine functional polymers bearing poly(ethylene glycol) (PEG) side chains were prepared using RAFT polymerization. A versatile postmodification strategy using activated ester units of N-methacryloxysuccinimide (NMS) and poly(ethylene glycol) methacrylate in the polymer chain afforded copolymers ranging from 6K to 50K with low polydispersities, along with tailored composition of each monomer along the copolymer chain. By controlling the monomer ratio, PEGMA molecular weight, time, and temperature, the composition could be tuned to study its effect on quantum dot functionalization. Representative oleate-capped CdSe/CdxZn1–xS QDs purified by a recently established gel permeation chromatography (GPC) method were used to test the effectiveness of the histamine-bearing polymers for preparation of water-soluble QDs. Successful ligand exchange of the QDs was characterized by good dispersions in water, lack of aggregation between QDs, and good quantum yields in water. Overall, the synthetic method demonstrates a facile and robust postmodification strategy for the formation of multiply binding, histamine-bearing copolymers, which can be applied to nanomaterials for fundamental investigations and bioimaging/biodistribution studies.

A versatile δ-aminolevulinic acid (ΑLA)-cyclodextrin bimodal conjugate-prodrug for PDT applications with the help of intracellular chemistry.

Grafting of δ-aminolevulinic acid (1) moieties on the narrow periphery of a β-cyclodextrin (β-CD) derivative through hydrolysable bonds was implemented, in order to generate a water-soluble, molecular/drug carrier with the capacity to undergo intracellular transformation into protoporphyrin IX (PpIX), an endogenous powerful photosensitizer for photodynamic therapy (PDT). The water-soluble derivative 2 was prepared by esterifying δ-azidolevulinic acid with heptakis(6-hydroxyethylamino-6-deoxy)-β-cyclodextrin, with an average degree of substitution, DS = 3. Delivery of water-soluble, colorless 2 to cells resulted in intense red fluorescence registered by confocal microscopy, evidently due to the engagement of the intracellular machinery towards formation of PpIX. Conjugate 2 was further complexed with a fluorescein-labeled model guest molecule which was successfully transported into the cells, thereby demonstrating the bimodal action of the derivative. The present work shows the versatility of CDs in smart applications and constitutes advancement to our previously shown PpIX-β-CD conjugation both in terms of water solubility and lack of aggregation.

Non-covalent functionalization of single-walled carbon nanotubes with modified polyethyleneimines for efficient gene delivery

Functionalized carbon nanotubes (CNTs) have been recently emerged as important class of vectors for delivery of DNA and other biomolecules into various cells. In this study, single-walled carbon nanotubes (SWNTs) were functionalized by non-covalent binding of hydrophobic moieties, which were covalently linked to polyethyleneimines (PEIs). PEIs of three molecular weights (25, 10 and 1.8kDa) were used. CNTs were functionalized with the PEI series either through phospholipid moiety (via a polyethyleneglycol linker) or through directly-attached long (18 carbons) or intermediate (10 carbons) hydrophobic alkyl moieties. All PEI-functionalized CNTs exhibited good stability and dispersibility in biological media. Visualizing of functionalized CNTs and lack of aggregation were confirmed by atomic force microscopy. The PEI derivatives bound to CNTs retained the ability to fully condense plasmid DNA at low N/P ratios and substantial buffering capacity in the endosomal pH range. PEI-functionalized CNTs exhibited increased transfection efficiency compared to underivatized PEIs up to 19-fold increase being observed in the functionalized CNT with the smallest PEI tested, the smallest hydrophobic attachment moiety tested and no linker. Also PEI-functionalized CNTs were effective gene delivery vectors in vivo following tail vein injection in mice with the largest expression occurring with the vector PEI-functionalized through a polyethyleneglycol linker.