Selecting analytical tools for characterization of polymersomes in aqueous solution

Abstract

Selecting the appropriate analytical methods for characterizing the assembly and morphology of polymer-based vesicles, or polymersomes are required to reach their full potential in biotechnology. This work presents and compares 17 different techniques for their ability to adequately report size, lamellarity, elastic properties, bilayer surface charge, thickness and polarity of polybutadienepolyethylene oxide (PB-PEO) based polymersomes. The techniques used in this study are broadly divided into scattering techniques, visualization methods, physical and electromagnetical manipulation, sorting/purification, and simulation tools. Of the analytical methods tested, Cryo-TEM and AFM turned out to be advantageous for polymersomes with smaller diameter than 200 nm, whereas confocal microscopy is ideal for diameters > 400nm. Polymersomes in the intermediate diameter range can be characterized using FF-Cryo-SEM and NTA. SAXS provides reliable data on bilayer thickness and internal structure, Cryo-TEM on multilamellarity. Taken together, these tools are valuable for characterizing polymersomes per se but the comparative overview is also intended to serve as a starting point for selecting methods for characterizing polymersomes with encapsulated compounds or polymersomes with incorporated biomolecules (e.g. membrane proteins).

Topological Insight into Superabsorbent Hydrogel Network Structures: a 1H Double‐Quantum NMR Study

“…Drying may cause morphological changes. Freeze‐fracture cryogenic electron microscopy (FF‐Cryo‐SEM or ‐TEM) can overcome vacuum‐induced sample deformation . Thus, noninvasive, fast, and reliable methods are searched for to characterize the polymeric network and its inhomogeneity.…”

SANS study on self-assembled structures of glucose-responsive phenylboronate ester-containing diblock copolymer

“…This simplified model described the SANS data rather well with a reduced χ 2 of 3.5. The scattering in the local structures of vesicles (around 0.1Å -1 ) [16,25], such as the conformation of the PEG chains, was difficult to extract due to very low polymer concentration. This, in turn, prohibited applying more sophisticated models to analyze the data.…”

“…This, in turn, prohibited applying more sophisticated models to analyze the data. Since the quality of the fit was good, a core-shell model with three layers in the shell [16] was not adopted. More sophisticated models will not lead to a unique set of parameters.…”

“…Dynamic light scattering (DLS), static light scattering, and transmission electron microscopy (TEM) have been frequently used to generate structural information of 5 micelles and vesicles formed by PBA-containing block copolymers [4,5,7,8,15]. Smallangle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) are powerful complementary techniques for revealing structures on the nano-meter scale and have been used to monitor in situ structural changes of block copolymer and surfactant assemblies [16][17][18][19][20]. In this work, self-assembled structures of PBE-containing diblock copolymers in water were studied using SANS for the first time.…”

Polimerossomos versus lipossomos: a evolução da "Bala Mágica"

“…O mesmo trabalho divide as técnicas em cinco grupos: técnicas de espalhamento, métodos visuais, manipulação física e eletromagnética, ensaios de purificação e ferramentas de simulação. 65 O tamanho fornecido pela técnica de espalhamento de luz dinâmico (do inglês dynamic light scattering, DLS) baseia-se no espalhamento da luz incidente a partir de um laser a uma intensidade induzida pelo movimento Browniano das partículas em solução, fornecendo o raio ou diâmetro hidrodinâmico a partir da equação de Stokes-Einstein, e assim deve ser correlacionado com análises microscópicas. 66 Resultados de DLS podem sugerir agregação dos sistemas ou indicar mudanças nos tamanhos dos sistemas mediante alterações de condições experimentais.…”