Influence of serum proteins on the kinetics of attachment of vero cells to cytodex microcarriers

Abstract

Abstract:The attachment characteristics of the Vero cell line on microcarriers has been found to be influenced by the serum proteins. Significant quantities of serum proteins were found to be adsorbed on the carrier surface, which resulted in decreased exchange capacity and a lower attachment rate constant. The kinetics of attachment followed primarily first order with respect to the concentration of free cells. With positively charged microcarriers the attachment process exhibited two distinct phases, an initial phase of normal attachment followed by a second phase characterized by a lower rate of attachment. The attachment rate constant in the first phase (0.062 min-l) was reduced to 0.01 min-' in the second phase. Presumably, at a low concentration of free Vero cells, the attachment process is retarded by unadsorbed Bovine Serum Albumin (BSA) and other serum proteins present in the medium.Key words : Vero cell, microcarrier, attachment kinetics, serum proteins.

Clinical-scale expansion of adipose-derived stromal cells starting from stromal vascular fraction in a single-use bioreactor: proof of concept for autologous applications

“…The first one was the modulation of PL concentration. The PL percentage was reduced to 0.5% during the first 24 h of culture to increase cell adhesion (Himes and Hu, ; Mukhopadhyay et al , ), and increased to 5% for the remaining culture to boost the ASC proliferation after adhesion. In addition to this modification, Pluronic® F‐68, which is a non‐ionic surfactant, was added to the culture medium as a shear protectant (Gigout et al , ; Hu et al , ; Murhammer and Goochee, ; Wu, ; Wu et al , ).…”

“…In addition, because other studies demonstrated that cell adhesion to microcarriers was improved using low serum quantity (Himes and Hu, ; Mukhopadhyay et al , ), we decreased the PL percentage to 0.5% at the beginning of the culture. A non‐ionic surfactant, the Pluronic® F68, was also added to the culture medium as a shear protectant (Gigout et al , ; Hu et al , ; Murhammer and Goochee, ; Wu, ; Wu et al , ).…”

Modulation of mesenchymal stem cell actin organization on conventional microcarriers for proliferation and differentiation in stirred bioreactors

“…Furthermore, poor cell adhesion on chitosan was attributed to the low ability of this matrix to adsorb fibronectin from serum‐containing solutions (Amaral et al ., ). In the same vein, the major protein adsorbed from serum on Cytodex‐1 MCs seems to be albumin (Mukhopadhyay et al ., ). In contrast, from previous chromatography studies, fibronectin is known to bind specifically on gelatin (or denatured collagen) (Brew and Ingram, ).…”

Growth behavior of number distributed adherent MDCK cells for optimization in microcarrier cultures

“…In all studies, [8][9][10][11] the number of viable cells in suspension and the number of cells attached to microcarriers was determined using a method first introduced by Sanford et al 12 and later modified by van Wezel 13 and Levine et al 14 For attached cells on microcarriers, a certain volume of 0.1 M citrate and 0.1% crystal violet was added to a representative sample and the number of released and stained nuclei counted in a haemocytometer. The number of attached cells was corrected using the recorded volume of settled microcarriers in the sample as reported by Napapetian et al 15 and Mukhopadhyay et al 16 Kong et al 17 and Wu et al 10 determined a half-life time for cell attachment that did not differ between the two complementary kinetics of cells attachment and decrease in suspension cells. Both authors concluded that the attachment of cells on microcarriers can be described with first-order kinetics.…”