title: NaCl-triggered self-assembly of hydrophilic poloxamine block copolymers.
abstract: Tetronic 1307 (T1307) is a hydrophilic poloxamine (HLB>24) with a high molecular mass owing to its long PEO and PPO blocks. In spite of good biocompatibility, its use as a component of drug delivery systems is limited by its high critical micelle concentration (CMC) and temperature (CMT). The aim of this work was to elucidate whether the addition of NaCl or the combination of salts and temperature may bring T1307 micellization and gelling features into more practically useful values. Increasing NaCl concentration in the 0.154 M (isotonic) to 2M (hypertonic) range made the copolymer more hydrophobic and more prone to self-assemble into unimodal micelles, as observed by means of π-A isotherms, (1)H NMR, dynamic light scattering (DLS), small-angle neutron scattering (SANS), and pyrene fluorescence. The decrease in CMC and CMT observed for T1307 in 0.5 M NaCl medium (tolerable hypertonic solution), compared to water, notably favored the solubility of hydrophobic drugs such as curcumin and quercetin. Moreover, phase diagram, intrinsic viscosity and sol-to-gel transition were markedly affected by NaCl concentration. Overall, the strong dependence of T1307 self-assembly features on NaCl opens interesting possibilities for tuning the performance of T1307 as a component of nanocarriers and in situ gelling systems.
authors: Department of Zoology, PT Sarvajanik College of Science, Surat 395001 India.
authors: Anita
authors: A
authors: Bahadur
authors: Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors: Sonia
authors: S
authors: Cabana-Montenegro
authors: Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors: Vinod Kumar
authors: VK
authors: Aswal
authors: Departamento de Química Física, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors: Emilio V
authors: EV
authors: Lage
authors: Departamento de Química Física, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors: Isabel
authors: I
authors: Sandez-Macho
authors: Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors: Angel
authors: A
authors: Concheiro
authors: Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain. Electronic address: carmen.alvarez.lorenzo@usc.es.
authors: Carmen
authors: C
authors: Alvarez-Lorenzo
authors: Chemistry Department, Veer Narmad South Gujarat University, Surat 395001 India. Electronic address: pbahadur2002@yahoo.com.
authors: Pratap
authors: P
authors: Bahadur
mesh_terms: D003474:Curcumin / Q000737:chemistry; D016503:Drug Delivery Systems; D004355:Drug Stability; D005029:Ethylenediamines / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D033363:Neutron Diffraction; D011073:Polyamines / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011794:Quercetin / Q000737:chemistry; D053838:Scattering, Small Angle; D012965:Sodium Chloride / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D014783:Viscosity
chemical_list: D005029:Ethylenediamines; D008823:Micelles; D011073:Polyamines; D011108:Polymers; C000610401:Tetronic 1307; D012965:Sodium Chloride; D011794:Quercetin; D003474:Curcumin
keywords: Block copolymers; Drug solubility; In situ gelling; Micelles; Osmolarity; Salt concentration; Self-assembly