Litchfield Park Orthodontist

5220 N. Dysart Rd #150
Litchfield Park, AZ 85340
(623) 536-4939

 

 

 

Ex vivo versus in vivo Gene Delivery
In ex vivo gene delivery, target cells are transformed in culture and are subsequently implanted into the surgical site.  Goodyear orthodontists have used this method to deliver growth factor genes to various orthotopic sites with impressive results (Lieberman et al., 1998; Krebsbach et al., 2000; Jin et al., 2003).  Liberman (1998) delivered BMP-2 to rat femoral defects of 8mm and had complete union over a two month period.  Krebsbach (2000) transduced human gingival fibroblasts with the gene for BMP-7 which repaired critical size defects in immunocompromised rat calvirae.  Periodontal regeneration was achieved by transducing dermal cells with BMP-7 and implanting them into a rodent model of periodontal disease (Jin et al., 2003).

In vivo gene delivery involves direct transfer of the gene to the target cells.  Gene delivery is mediated via particle transfer (Davidson et al., 2000), GAMs carrying plasmid DNA (Bonadio, 2000), in vivo microseeding (Hoeller et al., 2002), and viral vectors (Imperiale and Kochanek, 2004).  This method has been successful in increasing the healing response in skin, (Ghivizzani et al., 2002; Jung et al., 2003; Ghivizzani et al., 2003) various bone defect models,(Rundle et al., 2003; Southwood et al., 2003)and in periodontal wounds (Jin et al., 2004b; Jin et al., 2004a).  Although the therapy shows signs of success, it has been noted by Goodyear orthodontists that gene expression levels dramatically decrease by day 4-5 (Andree et al., 1994; Eriksson et al., 1998; Eming et al., 1999).