title: Phosphorylated, cellulose-based substrates as potential adsorbents for bone morphogenetic proteins in biomedical applications: a protein adsorption screening study using cytochrome C as a bone morphogenetic protein mimic.
abstract: Screening studies aimed at identifying useful biomedical materials that (when combined with implants) can attract bone morphogenetic proteins to their surfaces have been conducted. In this paper, the screening process has involved carrying out protein adsorption studies using cytochrome C, as a BMP protein mimic on phosphorylated cellulose-based substrates. These studies have shown that phosphorylation of cellulose produces materials that are capable of attracting the adsorption of cytochrome C to their surface. In contrast, negligible cytochrome C adsorption was observed on the unphosphorylated cellulose-based materials. The selective uptake of the positively charged cytochrome C (from solutions at pH 9.51) by the negatively charged phosphorylated cotton and microcrystalline cellulose substrates was primarily due to this protein's high isoelectric point (i.e.p) of 9.8 which gives it a positive charge at pH<i.e.p. Although this may be an obviously, well known attribute of protein adsorption behaviour, this property with respect to phosphorylated materials and its potential use for selective BMP adsorption onto biomedical materials, have not been reported directly in the literature. The work thus shows that the phosphorylated cellulose-based substrates should be seriously considered as carrier materials that could be used (with preloaded BMPs) as part of an implant system to assist in implant healing.
authors.affiliation: Chemistry Department, University of Waikato, Private Bag 3105, Hamilton, New Zealand. m.mucalo@waikato.ac.nz
authors.forename: Michael R
authors.initials: MR
authors.lastname: Mucalo
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kato
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yokogawa
mesh_terms: D000327:Adsorption; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D019485:Bone Morphogenetic Proteins / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D032561:Cotton Fiber; D045304:Cytochromes c / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D010766:Phosphorylation; D012710:Serum Albumin, Bovine / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001672:Biocompatible Materials; D019485:Bone Morphogenetic Proteins; D012710:Serum Albumin, Bovine; D002482:Cellulose; D045304:Cytochromes c