0000000000086334
AUTHOR
Harm-anton Klok
showing 6 related works from this author
Size- and coating-dependent uptake of polymer-coated gold nanoparticles in primary human dermal microvascular endothelial cells.
2012
A library-orientated approach is used to gain understanding of the interactions of well-defined nanoparticles with primary human endothelial cells, which are a key component of the vasculature. Fifteen sequentially modified gold nanoparticles (AuNPs) based on three different core sizes (18, 35, 65 nm) and five polymeric coatings were prepared. The synthetic methodology ensured homogeneity across each series of particles to allow sequential investigation of the chemical features on cellular interactions. The toxicity of these nanoparticles, their uptake behavior in primary human dermal microvascular endothelial cells (HDMECs), and quantification of uptake were all investigated. The results o…
Impact of polymer-modified gold nanoparticles on brain endothelial cells: exclusion of endoplasmic reticulum stress as a potential risk factor
2016
A library of polymer-coated gold nanoparticles (AuNPs) differing in size and surface modifications was examined for uptake and induction of cellular stress responses in the endoplasmic reticulum (ER stress) in human brain endothelial cells (hCMEC/D3). ER stress is known to affect the physiology of endothelial cells (ECs) and may lead to inflammation or apoptosis. Thus, even if applied at non-cytotoxic concentrations ER stress caused by nanoparticles should be prevented to reduce the risk of vascular diseases and negative effects on the integrity of barriers (e.g. blood-brain barrier). We exposed hCMEC/D3 to twelve different AuNPs (three sizes: 18, 35, and 65 nm, each with four surface-modif…
Squaric acid mediated chemoselective PEGylation of proteins: reactivity of single-step-activated α-amino poly(ethylene glycol)s.
2012
The covalent attachment of poly(ethylene glycol) (PEG) to therapeutically active proteins (PEGylation) has become an important method to deal with the pharmacological difficulties of these polypeptides, such as short body-residence times and immunogenicity. However, the derivatives of PEG used for PEGylation lack further functional groups that would allow the addition of targeting or labeling moieties. Squaric acid diethyl ester was used for the chemoselective single-step activation of poly(ethylene glycol)s into the respective ester amides. The resultant selective protein-reactive poly(ethylene glycol)s were investigated with respect to their selectivity towards amino acid residues in bovi…
Squaric Acid Mediated Synthesis and Biological Activity of a Library of Linear and Hyperbranched Poly(Glycerol)-Protein Conjugates
2012
Polymer-protein conjugates generated from side chain functional synthetic polymers are attractive because they can be easily further modified with, for example, labeling groups or targeting ligands. The residue specific modification of proteins with side chain functional synthetic polymers using the traditional coupling strategies may be compromised due to the nonorthogonality of the side-chain and chain-end functional groups of the synthetic polymer, which may lead to side reactions. This study explores the feasibility of the squaric acid diethyl ester mediated coupling as an amine selective, hydroxyl tolerant, and hydrolysis insensitive route for the preparation of side-chain functional, …
Uptake of poly(2-hydroxypropylmethacrylamide)-coated gold nanoparticles in microvascular endothelial cells and transport across the blood-brain barri…
2020
The facile and modular functionalization of gold nanoparticles makes them versatile tools in nanomedicine, for instance, photothermal therapy, contrast agents or as model nanoparticles to probe drug-delivery mechanisms. Since endothelial cells from various locations in the body exhibit unique phenotypes we quantitatively examined the amount of different sized poly(2-hydroxypropylmethacrylamide)-coated gold nanoparticles internalized into primary human dermal endothelial cells or human brain endothelial cells (hCMEC/D3) by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and visualized the nanoparticles using light and electron microscopy. Poly(2-hydroxypropylmethacrylamide)…
Impact of polymer-modified gold nanoparticles on brain endothelial cells: exclusion of endoplasmic reticulum stress as a potential risk factor
2016
A library of polymer-coated gold nanoparticles (AuNPs) differing in size and surface modifications was examined for uptake and induction of cellular stress responses in the endoplasmic reticulum (ER stress) in human brain endothelial cells (hCMEC/D3). ER stress is known to affect the physiology of endothelial cells (ECs) and may lead to inflammation or apoptosis. Thus, even if applied at non-cytotoxic concentrations ER stress caused by nanoparticles should be prevented to reduce the risk of vascular diseases and negative effects on the integrity of barriers (e.g. blood–brain barrier). We exposed hCMEC/D3 to twelve different AuNPs (three sizes: 18, 35, and 65 nm, each with four surface-modif…