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Nanocomposite Membrane-Based Photocatalytic Reactor for Degradation of Endocrine-Disrupting Compound in Water
Published in Chaudhery Mustansar Hussain, Ajay Kumar Mishra, Nanocomposites for Pollution Control, 2018
Hazlini Dzinun, Mohd Hafiz Dzarfan Othman, A. F. Ismail, Mohd Hafiz Puteh, Mukhlis A. Rahman, Juhana Jaafar
Since TiO2 has higher affinity to water than polymer, the penetration velocity of water into the membrane may increase with TiO2 content during the coagulation step. More porous were formed in membranes due to the increment of water solvent interdiffusion. During coagulation step, the DMAc which is soluble in water comes out of membranes, whereas TiO2 particles remain inside the membrane matrix and plug some of the membrane pores. This process can also be affected by particle aggregation phenomena. Because of this, the addition of different amounts of TiO2 yields different structures which are difficult to predict [25].
Directional Statistics of Preferential Orientations of Two Shapes in Their Aggregate and Its Application to Nanoparticle Aggregation
Published in Technometrics, 2018
Ali Esmaieeli Sikaroudi, David A. Welch, Taylor J. Woehl, Roland Faller, James E. Evans, Nigel D. Browning, Chiwoo Park
A particle aggregation is a merging of two smaller particles into one larger particle, which is one of the main driving forces that grow atoms or molecular clusters into nanoparticles during a chemical synthesis of nanoparticles. With a better understanding of a particle aggregation, synthesizing nanoparticles of desired sizes and shapes should be possible (Welch et al. 2016; Zhang et al. 2012; Li et al. 2012).
Polyethylenimine-based nanocarriers in co-delivery of drug and gene: a developing horizon
Published in Nano Reviews & Experiments, 2018
Abbas Zakeri, Mohammad Amin Jadidi Kouhbanani, Nasrin Beheshtkhoo, Vahid Beigi, Seyyed Mojtaba Mousavi, Seyyed Ali Reza Hashemi, Ayoob Karimi Zade, Ali Mohammad Amani, Amir Savardashtaki, Esmail Mirzaei, Sara Jahandideh, Ahmad Movahedpour
The transfusion efficiency is closely related to the PEI binding with DNA and the ability to overcome a specific barrier [38]. Trafficking and destruction of vectors in lysosomes is one of the main barriers to cellular gene transfer. Akinc et al., have used quantitative methods to study the mechanism of polyethylenimine-mediated DNA transfection. The results are in complete agreement with the proton sponge hypothesis and show that PEI-mediated transfection is effective in avoiding lysosomal trafficking [39]. Polymer/DNA, using a number of possible mechanisms that include DNA protection from enzymatic degradation, faciliting cellular absorption, promoting endolysosomal escape, DNA unpacking in the cytosol, the nucleus and escorting nuclear translocation of DNA or nanoparticles [40]. The excess PEI significantly improves the efficiency of transfection of amounts of polyplex [38]. The transfection process can be affected by many unknown factors. However, several studies have linked the transfection efficiency and cytotoxicity of PEI preparations to the physicochemical properties, the molecular weight and the branching ratio of polymer [41,42], the amount of DNA, the DNA ratio to the PEI, the timing and the solution conditions for complex formation, the transfection medium and cell density at time of transfer [43,44]. In addition, many factors, including temperature, surfactant, complex concentration, ionic strength, viscosity, pH, can significantly affect the aggregation process. Random reduction of particles, increasing electrostatic explosion, preventing particle accumulation and reducing hydrophobicity can make the complex stable [44,45]. Particle size can be mentioned as the important factors affecting the cellular absorption of particles within the cytoplasmic membrane [44,46]. Particle aggregation results from colloidal instability and particle swelling due to charge screening, are two factors contributing to increasing particle size. Salt ions increase the size of PEI-DNA complex and the transfer efficiency, and the longer incubation period has the opposite effect [40,44]. In 2004, Grosse et al., found that cytotoxic effects of PEI could be due to its ability to eliminate endosomes. In fact, this ‘proton sponge effect’ causes high gene transfer capacity. They showed that lactosylated PEI retains the ‘proton sponge effect’ of the polymer unchanged, which is essential for the efficient gene delivery [47].