“…When the scaffold is degraded, the encapsulated expression vector is adsorbed locally by the cells. The combination of gene therapy and scaffolds seems to greatly enhance both the efficiency and duration of transfected genes, leading to systems able to promote bone, cartilage, and osteochondral regeneration [22,23,26]. Scaffolds can be natural such as DBM, gelatine, alginate, fibrinogen and collagen based [16-18, 21, 27, 46, 52, 62, 71, 73, 84], or synthetic such as polyglycolic acid (PGA), polylactic acid (PLA) and poly(lactic-co-glycolide) (PLGA) [14,42,54,[82][83][84] (Table 1).…”