Subscriber access provided by UNIV OF CALIFORNIA SAN DIEGO LIBRARIES
Article
Vesicles Formation by Zwitterionic Micelle and PolyL-lysine: Solvation and Rotational Relaxation Study Jagannath Kuchlyan, Debasis Banik, Arpita Roy, Niloy Kundu, and Nilmoni Sarkar J. Phys. Chem. B, Just Accepted Manuscript • DOI: 10.1021/acs.jpcb.5b02893 • Publication Date (Web): 08 Jun 2015 Downloaded from http://pubs.acs.org on June 12, 2015
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Physical Chemistry B is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 23
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The Journal of Physical Chemistry
Vesicles Formation by Zwitterionic Micelle and Poly-L-lysine: Solvation and Rotational Relaxation Study Jagannath
Kuchlyan,
Debasis
Banik,
Arpita
Roy,
Niloy
Kundu,
and Nilmoni Sarkar* Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India E-mail:
[email protected]. Fax: 91-3222-255303 Abstract
The stable unilamellar vesicles formation, having large potential applications in biological as well as biomedical fields, has been investigated in aqueous solution composed of a zwitterionic surfactant, N-hexadecyl-N,N-dimethylammonio-1-propanesulfonate (SB-16) and water soluble cationic poly (amino acid), Poly-L-lysine (PLL). Dynamic light scattering (DLS), transmission electron microscopy (TEM), and other optical spectroscopic techniques revealed the transformation of SB-16 micelles in aqueous solutions into stable unilamellar vesicles above a certain concentration (0.008-0.1w/v %) of PLL. Solvation and rotational dynamics of coumarin 480 (C-480) give the information on hydration behavior around the head group regions of SB-16 micelle and SB-16/PLL vesicle. It was observed that the hydration nature around the head group regions of SB-16/PLL vesicular system is higher than the head groups regions of micellar system. Thus PLL permits to penetrate more water molecules in the head group regions of vesicular system.
Key Words: Polypeptide, Hydration, Self-assembly, Micelle-to-vesicle transition
1 ACS Paragon Plus Environment
The Journal of Physical Chemistry
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
1. Introduction: The formation of Vesicle is an important phenomenon because vesicles are biomimicing and have extensive applications in drug encapsulation and delivery, synthesis of nanoparticles and microreactors.1-4 Specially polypeptide based vesicles have great attention due to their similarity with cell membranes and important applications in biomedical researches.5-7 Recently there has been a growing in research interest for the preparation and characterization of polypeptide based materials.6 Synthetic poly(amino acid) have been extensively used for the preparation of polymeric vesicles.8-12 Using poly(L-arginine) or poly(L-lysine) as the hydrophilic part and poly(L-leucine) as the hydrophobic part, Deming and coworkers6 prepared poly(amino acid) vesicles. In comparison to conventional liposomes, poly (amino acid) based vesicles showed higher membrane properties, better stability and various applications in the fields of chemistry and biology.5,6,9,13 Therefore there has been an important research concern on the synthesis, designing, and modification of polypeptide based vesicles for a wide range of applications, ranging from material science to biomedical science. There are a number of reported on the preparation of unilamellar vesicles by simple mixing of surfactant solution.14-15Very recently our group prepared unilamellar vesicle by mixing cholesterol with various types of surfactants.14 Stable vesicles have been obtained from many surfactant mixtures such as cationic/anionic, cationic/cationic, nonionic/ionic, zwitterionic/anionic and zwitterionic/cationic systems but there are only a few studies in case of surfactant/poly(amino acid) systems.15-21 Here, we have shown vesicle formation with zwitterionic surfactant and amino acid based polymer. Zwitterionic surfactants are insensitive to variation of the ionic strength and temperature and mildness in a general sense.22 It is previously reported that Zwitterionic surfactants have strong interaction with polymer.20 Studies on polypeptide based block or graft copolymers revealed that they can self-assemble to form micelles or vesicles which have been extensively investigated due to their biocompatibility, stimuli-responsiveness and having the requisite structures and functions of proteins.23-29 The demand of polypeptides in pharmaceutical or biomedical field is increasing due to their biocompatibility and biodegradability. A significant number of reports regarding the use of synthetic polypeptides for biomedical applications are fascinated on water-soluble polypeptides, in particular poly(L-lysine) or poly(L-arginine) as polycations and poly(L-aspartic acid) or poly(L-glutamic acid) as polyanions, as well as on various polypeptide copolymers using 2 ACS Paragon Plus Environment
Page 2 of 23
Page 3 of 23
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
The Journal of Physical Chemistry
adapted synthetic routes.6 Poly-L-lysine (PLL) polymers are polypeptides with amino acid Llysine as a repetitive unit.30-31 They are biodegradable, good antimicrobial agents and also they are used in numerous materials including drug delivery systems. The secondary structures of PLL have been extensively studied in aqueous solution using various spectroscopic techniques.32 Due to presence of primary amine groups with its backbone PPL is cationic when the environmental pH is lower than its isoelectric point which is around 9.0.30 It is one of the first cationic polymers used for gene transfer due to their low immunogenicity. Being a cationic polypeptide, Poly-L-lysine (PLL) can be used as a modifier for drug carriers and also to increase the cellular consumption of drugs by enhancing the permeability of various compounds. Polycations including PLL show stimulus activity towards fabrication of immunoglobulin, which makes their existence in higher organisms.33-35The antimicrobial capability of PPL depend on its cationic nature because PPL is adsorbed on negatively charged cell surfaces of microorganisms through electrostatic interactions and this leads to cell membrane disruption.36 It is reported that an oligomeric connecting molecule Lys-12-Lys on mixing with sodium dodecyl sulfate (SDS) in aqueous solution can form vesicles.24 The interaction of SDS with Lys12-Lys occur through head groups by electrostatic attraction and hydrogen bonds assisted by hydrophobic interaction between the tail groups. The binding with SDS head groups is facilitated by the presence of positive charges and the hydrogen bonding sites in Lys-12-Lys. A great improvement in the production of supramolecular amphiphiles was made by Zhang and coworkers using noncovalent interactions, followed by the contribution of comprehensive reviews.37-39 The vesicles composed of soft materials utilize their interior cavities for the encapsulation of water and other guest molecules. Bearing such properties vesicles have most promising potential application in various fields.40-43 Solvation dynamics gives useful information regarding the microenvironments of vesicles. Dynamics of solvent molecules and their chemical and biological effects are attractive topics for current research. Micelles, reverse micelles, and lipid bilayers mimic biological systems; as a result various research groups have used both experimental and theoretical methods to develop the solvation dynamics in various organized assemblies.44-47 Solvation in bulk water is very rapid (
