The
present work evaluates the effect of nanoparticle size on the
structure and function of albumin proteins. Further, the work evaluates
the nature of binding between low molecular weight (∼20 kDa)
chitosan oligosaccharide nanoparticles (COS NPs) and high molecular
weight (∼85–90 kDa) chitosan nanoparticles (CS NPs)
with two model proteins, namely, human serum albumin (HSA) and bovine
serum albumin (BSA). The size-dependent pattern of protein-adsorption
onto nanoparticle surface was studied using dynamic light scattering
and further quantified by size exclusion chromatography-HPLC method.
Circular dichroism spectroscopy revealed that both the proteins underwent
conformational change upon association with the cationic nanoparticulate
systems. Further, fluorescence spectroscopy was used to probe the
stability of nanoparticle–protein complexes, by determining
the binding constants of nanoparticle to protein and to evaluate the
thermodynamic parameters of the interacted proteins. Smaller-sized
NPs, in case of both the polymers, exhibited greater protein binding
and increased conformational loss in proteins. Also, CS NPs resulted
in lesser change in protein structure, thereby indicating a better
biocompatibility than COS NPs. This observation was supported by the
results of fluorescence spectroscopy, which implicated that the CS
NPs (110 nm) formed the most stable, ground-state complex with HSA,
which had a binding constant (K
b) of 6.76
× 104 M–1. Results from this investigation
provide valuable insights into the molecular level interactions taking
place at nanobiointerfaces, which can help in engineering stable,
nanoscale materials of chitosan biopolymer and will be helpful to
understand the nanoparticle toxicity for biomedical applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.