Table 1.

Physical and MRI characteristics of the different magnetic PLGA particles made for this study, showing particle size and iron oxide content. Particle size values are mean +/− s.d. n> 50 particles.

Particle characteristics	nanoparticles			microparticles
Magnetite:PLGA	0:1	1:1	2:1	0:1	1:1	2:1
Particle size, nm	105±37	95±34	105±62	2100±1100	920±510	920±790
Magnetite content, wt%	0	56.7	83.7	0	58.2	66.1
r2, s−1mM−1 iron	-	196	28.5	-	44.7	38.7
r2, s−1mM−1 particle	-	8.91 ×108	3.95 ×108	-	1.937 ×1011	2.11 ×1011
r2*, s−1mM−1 iron	-	659.1	243	-	384.1	614.1
r2*, s−1mM−1 particle	-	2.99 ×109	3.37 ×109	-	1.65 ×1012	3.35 ×1012