Influence of surface chemistry and morphology of nanoparticles on protein corona formation

Nanomaterials offer promising solutions as drug delivery systems and imaging agents in response to the demand for better therapeutics and diagnostics. However, the limited understanding of the interaction between nanoparticles and biological entities is currently hampering the development of new systems and their applications in clinical settings. Proteins and lipids in biological fluids are known to complex with nanoparticles to form a “biomolecular corona”. This has been shown to affect particles' morphology and behavior in biological systems and their interactions with cells. Hence, understanding how nanomaterials' physicochemical properties affect the formation and composition of this biocorona is a crucial step. This work evaluates existing literature on how morphology (size and shape), and surface chemistry (charge and hydrophobicity) of nanoparticles influence the formation of protein corona. The latest evidence suggest that although surface charge promotes the interaction with proteins and lipids, surface chemistry plays a leading role in determining the affinity of the nanoparticle for biomolecules and, ultimately, the composition of the corona. More recently the study of additional nanoparticles' properties like shape and surface chirality have demonstrated a significant effect on protein corona architecture, providing new tools to tailor biomolecular corona formation. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies. Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials

Expansions for the Bollobas-Riordan polynomial of separable ribbon graphs

We define 2-decompositions of ribbon graphs, which generalise 2-sums and tensor products of graphs. We give formulae for the Bollobas-Riordan polynomial of such a 2-decomposition, and derive the classical Brylawski formula for the Tutte polynomial of a tensor product as a (very) special case. This study was initially motivated from knot theory, and we include an application of our formulae to mutation in knot diagrams.Comment: Version 2 has minor changes. To appear in Annals of Combinatoric

Characterization of seed proanthocyanidins of thirty-two red and white hybrid grape varieties

Grape seed extracts are known for their beneficial effects on health and on cardiovascular diseases due to antioxidant activity and the free radical-scavenging properties of proanthocyanidins (PAs). Moreover, grape seed tannins are used in oenology as additives to improve the organoleptic characteristics of wines, and for the clarification of must and wines. PAs in seed extract of 32 hybrid and three V. vinifera grape varieties were characterized by MALDI-TOF mass spectrometry. Signals of 148 compounds were identified as [M+H]+, [M+Na]+ and [M+K]+ adducts of B-type and A-type PAs formed from catechin/epicatechin subunits up to undecamers and with galloylation degree 0-7. The number-average molecular weight (Mn) of the samples, a parameter correlated with the molecular weight of polymers, and the polyphenolic content of extract, were also determined. Profiles of the hybrid grape varieties were compared with those of three V. vinifera samples studied as references. 'Terzi 108-6' showed high content of antioxidant polyphenols and 'Seyve Villard 12-390' higher content of higher oligomers. These two grape varieties are therefore potentially very interesting as sources of antioxidants and tannins for nutraceutical and oenological uses

Fast Evaluation of Interlace Polynomials on Graphs of Bounded Treewidth

We consider the multivariate interlace polynomial introduced by Courcelle (2008), which generalizes several interlace polynomials defined by Arratia, Bollobas, and Sorkin (2004) and by Aigner and van der Holst (2004). We present an algorithm to evaluate the multivariate interlace polynomial of a graph with n vertices given a tree decomposition of the graph of width k. The best previously known result (Courcelle 2008) employs a general logical framework and leads to an algorithm with running time f(k)*n, where f(k) is doubly exponential in k. Analyzing the GF(2)-rank of adjacency matrices in the context of tree decompositions, we give a faster and more direct algorithm. Our algorithm uses 2^{3k^2+O(k)}*n arithmetic operations and can be efficiently implemented in parallel.Comment: v4: Minor error in Lemma 5.5 fixed, Section 6.6 added, minor improvements. 44 pages, 14 figure

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Study of protein corona formation and its impact on the morphology and properties of acrylamide-based nanogels

The application of nanomaterials to the field of medicine offers exciting and promising therapeutic strategies which are expected to positively impact the quality of life of future patients. In particular, polymeric acrylamide-based nanogels represent low toxic profile, drug loading capacity and tuneable stimuli responsive properties, which make them suitable nanomaterials for potential drug delivery applications. However, the rational design and development of successful nanomedicines is currently hampered by the lack of a broad understanding on the “nano-bio” interface, which comprises the dynamic physiochemical interactions between nanomaterials and biological components such as proteins, cellular membranes, and lipids. In the past 15 years, the study of the interactions between nanomaterials and proteins (protein corona) has gained importance; the protein corona has been shown to affect many aspects of nanomaterials such as toxicity, bioavailability, cell interaction, and targeting, often resulting detrimental for their use in biological settings. Although research efforts have improved the understanding of the protein corona, many limitations are currently in place. The lack of a broad set of techniques able to evaluate the protein corona in situ (without NP-protein complex isolation) limits our understanding of the more subtle and elusive interactions (soft corona). Moreover, the effect of protein corona on important physico-chemical properties of nanoparticles such as interfacial behaviour and response to stimuli are not understood, which makes the assessment of novel strategies to overcome (or exploit) the protein corona more challenging. This project represents a contribution to the area of nanoparticle-protein interactions, aiming to (I) understand the role that the chemical and morphological properties of polymeric nanogels play in the formation of protein corona, (II) develop novel analytical approach to investigate the in situ protein corona formation, and (III) study the effect of protein corona on the properties of nanomaterials (i.e. their interfacial and stimuli responsive properties). Chapter 1 provides an introduction to the advances in the area of novel nanomaterials as drug delivery vehicles and the evaluation of their protein corona formation. This includes a specific overview of the progresses in the development of polymeric nanogels drug delivery platforms. In Chapter 2, we evaluate the use of surface force tensiometry as a novel approach to investigate the formation of nanogel-protein complexes in solution and their adsorption at the air/water interface. The role played by the chemical structure of the nanogels and model proteins on their complex formation and interfacial behaviour are elucidated. In Chapter 3, the ability of protein corona to alter the thermoresponsive properties of NIPAM- and NPAM-based nanogels was studied. In Chapter 4, the in vitro toxicity and cellular internalisation of neutral and positively charged nanogels in brain endothelial cells (hCMEC/D3) and the effect of proteins in media was assessed. Finally, the conclusions of this research project along with future perspectives are presented in Chapter 5; This is followed by a detailed section of materials and methods (Chapter 6) and references

Ion trap mass spectrometry, a new tool in the investigation of drugs of abuse in hair

The use of an ion trap mass spectrometer for the detection, via tandem mass spectrometry, of morphine and cocaine in the hair of drug addicts proved to be successful. In particular, detection limits of 1-20 ppb for morphine and 5-30 ppb for cocaine were achieved, with good reproducibility and absence of interferent specie