Characterization and Quantitation of Carbon Black Nanomaterials in Polymeric and Biological Aqueous Dispersants by Asymmetrical Flow Field Flow Fractionation.
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ABSTRACT:
SUBMITTER: Sanjuan-Navarro L
PROVIDER: S-EPMC8637946 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Liposomal formulations for the treatment of cancer and other diseases are the most common form of nanotechnology enabled pharmaceuticals (NEPs) submitted for market approval and in clinical application today. The accurate characterization of their physical-chemical properties is a key requirement; in particular, size, size distribution, shape, and physical-chemical stability are key among properties that regulators identify as critical quality attributes. Here we develop and validate an optimized method, based on multi-detector asymmetrical-flow field flow fractionation (MD-AF4) to accurately and reproducibly separate liposomal drug formulations into their component populations and to characterize their associated size and size distribution, whether monomodal or polymodal in nature. In addition, the results show that the method is suitable to measure liposomes in the presence of serum proteins and can yield information on the shape and physical stability of the structures. The optimized MD-AF4 based method has been validated across different instrument platforms, three laboratories, and multiple drug formulations following a comprehensive analysis of factors that influence the fractionation process and subsequent physical characterization. Interlaboratory reproducibility and intra-laboratory precision were evaluated, identifying sources of bias and establishing criteria for the acceptance of results. This method meets a documented high priority need in regulatory science as applied to NEPs such as Doxil and can be adapted to the measurement of other NEP forms (such as lipid nanoparticle therapeutics) with some modifications. Overall, this method will help speed up development of NEPS, and facilitate their regulatory review, ultimately leading to faster translation of innovative concepts from the bench to the clinic. Additionally, the approach used in this work (based on international collaboration between leading non-regulatory institutions) can be replicated to address other identified gaps in the analytical characterization of various classes of NEPs. Finally, a plan exists to pursue more extended interlaboratory validation studies to advance this method to a consensus international standard.
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Project description:Applications of asymmetrical flow field-flow fractionation (AF4) continue to expand rapidly in the fields of nanotechnology and biotechnology. In particular, AF4 has proven valuable for the separation and analysis of particles, biomolecular species (e.g., proteins, bacteria) and polymers (natural and synthetic), ranging in size from a few nanometers to several micrometers. The separation of non-spheroidal structures (e.g., rods, tubes, etc.) with primary dimensions in the nanometer regime, is a particularly challenging application deserving of greater study and consideration. The goal of the present study was to advance current understanding of the mechanism of separation of rod-like nano-objects in the AF4 channel. To achieve this, we have systematically investigated a series of commercially available cetyltrimethylammonium bromide stabilized gold nanorods (AuNRs), with aspect ratios from 1.7 to 10. Results show clearly that the retention time is principally dependent on the translational diffusion coefficient of the AuNRs. Equations used to calculate translational and rotational diffusion coefficients (cylinder and prolate ellipsoid models) yield similarly good fits to experimental data. Well characterized gold nanorods (length and diameter by transmission electron microscopy) can be used as calibrants for AF4 measurements allowing one to determine the aspect ratio of nanorod samples based on their retention times. Graphical abstract ?.
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Project description:Asymmetrical flow field-flow fractionation (AF4) is a chromatographic separation technique that can be used for a broad range of particles or macromolecules. As an orthogonal method to size exclusion chromatography (SEC) with a much broader separation size range (1-800 nm) AF4 is gaining importance. However, the data evaluation capacities are far behind in comparison to other techniques like analytical ultracentrifugation (AUC). A program for evaluation of data from AF4 with a coupled multiangle laser light scattering (MALLS) detector was developed that allows the determination of the distributions of diffusion coefficients ( D), hydrodynamic radii ( Rh), molecular weights ( Mw), and relative concentrations (RC) of the obtained species. In addition, two algorithms to remove broadening effects via deconvolution were implemented and tested for their validity. The first is an extension of the known diffusion broadening correction applying the entire diffusion coefficient distribution instead of a single diffusion coefficient. The second applies the Richardson-Lucy algorithm for the deconvolution of overlapping signals from stars in astronomy. This program allows a reproducible strong enhancement of the fractogram resolution allowing for entire baseline separations of proteins. The comparison of the values for Mw determined by a partial Zimm plot from each data point of the original fractogram and the deconvolved results shows that especially the Richardson-Lucy algorithm maintains a high degree of data robustness.
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