title: Self-assembled carrageenan/protamine polyelectrolyte nanoplexes-Investigation of critical parameters governing their formation and characteristics.
abstract: The aim of this work was to investigate the feasibility of cross-linker free polyelectrolyte complex formation at the nanoscale between carrageenan (CAR) and protamine (PROT). The properties of CAR/PROT nanoparticles (NPs) were dependent on the carrageenan type: kappa (KC), iota (IC) and lambda (LC), concentration of components, addition of divalent cations, weight mixing ratio (WMR) of constituents and mode of component addition. In the case of 0.1% w/v solutions, IC-based NPs had the smallest particle sizes (100-150nm) and low polydispersity indices (0.1-0.4). A decrease in the solution concentration from 0.1% to 0.05% w/v enabled the formation of KC/PROT NPs. All carrageenans exhibited the ability to form NPs with surface charge ranging from -190 to 40mV. The inclusion of divalent cations caused an increase in the particle size and zeta potential. Infrared analysis confirmed the presence of a complex between CAR and PROT and showed that IC chains undergo structural changes when forming NPs. Colloidal stability of NPs was related to the initial surface charge of particles and was time- and pH-dependent. IC was found to be the most suitable type of CAR when forming nanoplexes with PROT.
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland. Electronic address: mdul@tcd.ie.
authors.forename: Maria
authors.initials: M
authors.lastname: Dul
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland; Bradford School of Pharmacy, School of Life Sciences, Centre for Pharmaceutical Engineering Science, University of Bradford, Norcroft Building, Richmond Road, Bradford BD7 1DP, W. Yorks., UK. Electronic address: K.J.Paluch@bradford.ac.uk.
authors.forename: Krzysztof J
authors.initials: KJ
authors.lastname: Paluch
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland. Electronic address: hakelly@tcd.ie.
authors.forename: Hazel
authors.initials: H
authors.lastname: Kelly
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland. Electronic address: healyam@tcd.ie.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Healy
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland. Electronic address: sassea@tcd.ie.
authors.forename: Astrid
authors.initials: A
authors.lastname: Sasse
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin 2, Ireland. Electronic address: lidia.tajber@tcd.ie.
authors.forename: Lidia
authors.initials: L
authors.lastname: Tajber
mesh_terms: D002118:Calcium / Q000737:chemistry; D002351:Carrageenan / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011479:Protamines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D015032:Zinc / Q000737:chemistry
chemical_list: D004573:Electrolytes; D007477:Ions; D011479:Protamines; D002351:Carrageenan; D015032:Zinc; D002118:Calcium
keywords: Carrageenan; Dynamic light scattering; Infrared spectroscopy; Nanoparticles; Polyelectrolyte complexes; Protamine