@article {2425,
	title = {Decoding the Kinetic Pathways toward a Lipid/DNA Complex of Alkyl Alcohol Cationic Lipids Formed in a Microfluidic Channel.},
	journal = {J Phys Chem B},
	volume = {126},
	year = {2022},
	month = {2022 Jan 27},
	pages = {588-600},
	abstract = {<p>Complexes of cationic liposomes with DNA have emerged as promising nonviral vectors for delivering genetic information into cells for gene therapy. Kinetics of the liposome/DNA complex (lipoplex) formation on a millisecond time scale are studied by monitoring time evolution of fluorescence of 8-anilino-1-naphthalene sulfonic acid (ANS) and ethidium bromide (EtBr) in a continuous flow microfluidic channel coupled to a fluorescence microscope. The formation of lipoplexes between calf thymus DNA and liposomes based on two novel cationic lipids (Lip1810 and Lip1814) are found to follow a two-step process with kinetic constants for the Lip1814/DNA complex ( = 1120-1383 s, = 0.227-1.45 s) being significantly different from those ( = 68.53-98.5 s, = 32.3-60.19 s) corresponding to formation of the Lip1810/DNA complex. The kinetic pathway leading to the formation of Lip1814/DNA complex is whereas the formation of Lip1810/DNA complex occurs by a . The observed difference in the kinetics of lipoplex formation likely originates from different structures of the lipid/DNA complexes.</p>
},
	issn = {1520-5207},
	doi = {10.1021/acs.jpcb.1c07263},
	author = {Mukherjee, Dipanjan and Hasan, Md Nur and Ghosh, Ria and Ghosh, Gourab and Bera, Arpan and Prasad, Sujanthi Easwara and Hiwale, Ankita and Vemula, Praveen K and Das, Ranjan and Pal, Samir Kumar}
}
@article {2146,
	title = {Differential flexibility leading to crucial microelastic properties of asymmetric lipid vesicles for cellular transfection: A combined spectroscopic and atomic force microscopy studies.},
	journal = {Colloids Surf B Biointerfaces},
	volume = {196},
	year = {2020},
	month = {2020 Sep 21},
	pages = {111363},
	abstract = {<p>The role of microscopic elasticity of nano-carriers in cellular uptake is an important aspect in biomedical research. Herein we have used AFM nano-indentation force spectroscopy and F{\"o}rster resonance energy transfer (FRET) measurements to probe microelastic properties of three novel cationic liposomes based on di-alkyl dihydroxy ethyl ammonium chloride based lipids having asymmetry in their hydrophobic chains (Lip1818, Lip1814 and Lip1810). AFM data reveals that symmetry in hydrophobic chains of a cationic lipid (Lip1818) imparts higher rigidity to the resulting liposomes than those based on asymmetric lipids (Lip1814 and Lip1810). The stiffness of the cationic liposomes is found to decrease with increasing asymmetry in the hydrophobic lipid chains in the order of Lip1818 \&gt; Lip1814 \&gt; lip1810. FRET measurements between Coumarin 500 (Donor) and Merocyanine 540 (Acceptor) have revealed that full width at half-maxima (hw) of the probability distribution (P(r)) of donor-acceptor distance (r), increases in an order Lip1818 \&lt; Lip1814 \&lt; Lip1810 with increasing asymmetry of the hydrophobic lipid chains. This increase in width (hw) of the donor-acceptor distance distributions is reflective of increasing flexibility of the liposomes with increasing asymmetry of their constituent lipids. Thus, the results from AFM and FRET studies are complementary to each other and indicates that an increase in asymmetry of the hydrophobic lipid chains increases elasticity and or flexibility of the corresponding liposomes. Cell biology experiments confirm that liposomal flexibility or rigidity directly influences their cellular transfection efficiency, where Lip1814 is found to be superior than the other two liposomes manifesting that a critical balance between flexibility and rigidity of the cationic liposomes is key to efficient cellular uptake. Taken together, our studies reveal how asymmetry in the molecular architecture of the hydrophobic lipid chains influences the microelastic properties of the liposomes, and hence, their cellular uptake efficiency.</p>
},
	issn = {1873-4367},
	doi = {10.1016/j.colsurfb.2020.111363},
	author = {Mukherjee, Dipanjan and Rakshit, Tatini and Singh, Priya and Mondal, Suman and Paul, Debashish and Ahir, Manisha and Adhikari, Arghya and Puthiyapurayil, Theja P and Vemula, Praveen Kumar and Senapati, Dulal and Das, Ranjan and Pal, Samir Kumar}
}
