Table 3:

Cell viability of AMDCs in PBS and collagen following injection with 22 and 27G needles immediately after injection, at 24 and 48 hours.

Needle gauge/length	Delivery vehicle	0 hr. viability (%)	24 hr. viability (%)	48 hr. viability (%)
22G, 3.5in	Collagen	97.27 ± 1.9	100	99.5 ± 0.5^a
22G, 3.5in	PBS	86.9 ± 4.6^a	77.9 ± 6.9^a	70.8 ±10.8^a
27G,3.5 in	Collagen	100	100	100
27G,3.5 in	PBS	89.4 ± 3.2^a	80.3 ± 6.2^a	70.0 ± 10.8^a
27G, 9.5in	Collagen	100	100	100
27G, 9.5in	PBS	96.9 ± 1.5^a	93.4 ± 19.6^a	82.4 ± 8.1^a

Note: Cell-collagen suspensions maintained high viability compared to cell-PBS suspensions, showing progressive cell loss at 24 and 48 hours. Mean ± SEM, n=3

represents a significant difference from collagen treated group, p< 0.05.