Protein resistant surfaces: Comparison of acrylate graft polymers bearing oligo-ethylene oxide and phosphorylcholine side chains
Notice bibliographique
Résumé
The objective of this work was to compare poly(ethylene glycol) (PEG) and phosphorylcholine (PC) moieties as surface modifiers with respect to their ability to inhibit protein adsorption. Surfaces were prepared by graft polymerization of the methacrylate monomers oligo(ethylene glycol) methyl ether methacrylate (OEGMA, MW 300, PEG side chains of length n=4.5) and 2-methacryloyloxyethyl phosphorylcholine (MPC, MW 295). The grafted polymers thus contained short PEG chains and PC, respectively, as side groups. Grafting on silicon was carried out using surface-initiated atom transfer radical polymerization (ATRP). Graft density was controlled via the surface density of the ATRP initiator, and chain length of the grafts was controlled via the ratio of monomer to sacrificial initiator. The grafted surfaces were characterized by water contact angle, x-ray photoelectron spectroscopy, and atomic force microscopy. The effect of graft density and chain length on fibrinogen adsorption from buffer was investigated using radio labeling methods. Adsorption to both MPC- and OEGMA-grafted surfaces was found to decrease with increasing graft density and chain length. Adsorption on the MPC and OEGMA surfaces for a given chain length and density was essentially the same. Very low adsorption levels of the order of 7 ngcm(2) were seen on the most resistant surfaces. The effect of protein size on resistance to adsorption was studied using binary solutions of lysozyme (MW 14 600) and fibrinogen (MW 340 000). Adsorption levels in these experiments were also greatly reduced on the grafted surfaces compared to the control surfaces. It was concluded that at the lowest graft density, both proteins had unrestricted access to the substrate, and the relative affinities of the proteins for the substrate (higher affinity of fibrinogen) determined the composition of the layer. At the highest graft density also, where the adsorption of both proteins was very low, no preference for one or the other protein was evident, suggesting that adsorption did not involve penetration of the grafts and was occurring at the outer surface of the graft layer. It thus seems likely that preference among different proteins based on ability to penetrate the graft layer would occur, if at all, at a grafting density intermediate between 0.1 and 0.39 cm(2). Again the MPC and OEGMA surfaces behaved similarly. It is suggested that the main determinant of the protein resistance of these surfaces is the "water barrier layer" resulting from their hydrophilic character. In turn the efficacy of the water barrier depends on the monomer density in the graft layer.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».