The use of transferrin in Cell Culture is a method for providing iron to the cells. The delivery of iron using transferrin has been well documented for cell culture systems and in biomanufacturing of therapeutic proteins, such as monoclonal antibodies. Transferrin is derived from both animal and human serum sources for use in these processes. Recently, a move is being made towards animal and human-free cell culture systems. The employment of a human recombinant alternative to transferrin would prove optimal for cell culture as well as for biomanufacturing.

Lacromin™

Recombinant human lactoferrin, Lacromin™ (InVitria) is a cell culture grade recombinant human lactoferrin (rhLF) that is produced from an animal- and human-free plant based expression system, ExpressTec (Nandi et al., Transgen. Res., 2005). Lacromin™ is a 80 kD glycoprotein belonging to the transferrin family of proteins and has an amino-acid homology and similar iron biding properties to human transferrin. Lacromin™ is a multi-functional protein, as such it is a cell growth factor, a source of iron, delays apoptosis and displays anti-microbial properties. Lacromin™ has been reported to have synergistic effects with both EGF (Kohno et al., Acta. Paedietr., 1993) and bFGF on cell growth (Shinoda et al., Adv. Exp. Med. Biol., 1994).

Osteoblast Cells for Use in Tissue Engineering

Osteoblast cells produce a bone matrix and result in increase bone mass. These cells are being studied for application in 3D scaffolds cultured in bioreactors for In Vitro tissue engineering of bone (Xiaojun et al., Proc Natl. Acad. Sci. U.S.A., 2004).

The Effect of Lacromin™ on Osteoblast Cell Growth

Rat osteoblast cells were cultured in a serum-free medium supplemented with 1% BSA either without or in the presence of recombinant human lactoferrin (holo-rhLF) to assess for cell stimulation by holo-rhLF as determined by [3H]-thymidine incorporation. A dose response for the concentrations of 0.1, 1, 10 and 100 mg/L was assessed. At the concentration of 100 mg/L, cell doubling was twice as much as for the group not receiving supplementation with holo-rhLF. A significant effect on cell growth was observed even at the concentration of 0.1 mg/L (Haung et al., In Vitro Cell. Dev. Biol.-Animal., 2008). Cornish et al., Endocrin., 2004, reported comparable results of lactoferrin on cell growth of osteoblast cells.

Conclusions

Holo-hLF, Lacromin™ (InVitria) promotes cell growth in osteoblast cells. Additional advantages of Lacromin™ include high and stable expression of recombinant proteins, tissue specific expression in grain endosperm, rapid scalability to metric-ton quantities, prevention of Gene flow with self pollinating crops, low capital investment and production costs, and efficient processing and recovery (Huang, BioProcess, 2004).

The use of Lacromin™ in the culture of osteoblast cells provides effective growth stimulation (InVitria Lacromin™ product brochure, www.InVitria.com) and employment of a human recombinant lactoferrin would prove optimal for cell culture as well as for biomanufacturing.

Forbes.com, Press Release: http://www.forbes.com/prnewswire/feeds/prnewswire/2008/10/10/prnewswire200810101418PR_NEWS_USPR_____AQF037.html.