PODS™ proteins are made using an insect cell expression system in which the active protein is co-expressed alongside polyhedrin carrier protein. Polyhedrin forms microcrystals within insect cells which specifically capture the active protein to form a co-crystal complex.
The active protein is captured in its nascent, natively folded form with limited scope for proteolytic degradation. Consequently, excellent levels of bioactivity are observed. The PODS™ co-crystals provide a sustained release mechanism and can be used to functionalize surfaces. For further details, please refer to the PODS™ Technology page.
The product contains the polyhedrin protein co-crystalized with Human Wnt-3a. Wnt-3a signalling has been implicated in the control of differentiation of stem cells. Wnt proteins have been shown to regulate cell-to-cell interactions during embryogenesis, more specifically regulating mesoderm differentiation and osteogenesis. The Wnts have also been shown to have putative roles in the regulation of adult stem cells.
PODS™ co-crystals provide a depot of proteins which are steadily secreted. It has been estimated that the biological activity of 50 million PODS™ co-crystals generates the same peak dose as 3.3 μg of standard recombinant protein. However, at 5 days following the start of seeding the PODS™ co-crystals, there are more than 50% of these peak levels still present in the culture system.
Ultimately, the amount of PODS™ co-crystals that is optimal for a particular experiment should be determined empirically. Based on previous data, we suggest using 50 million PODS™ co-crystals in place of 3.3 μg of standard growth factor as a starting point."
To control for cross-reactivity with cells or as a negative control, we recommend using PODS™ growth factors alongside PODS™ Empty crystals, as the latter do not contain or release cargo protein.
Wingless type 3, MMTV integration site family member 3A, Wnt 3a, Wnt3a