Human serum albumin nanoparticles for ocular delivery of bevacizumab
Inés Luis de Redín 1 , Carolina Boiero 2 , María Cristina Martínez-Ohárriz 3 , Maite Agüeros 1 , Rocío Ramos 4 , Iván Peñuelas 4 , Daniel Allemandi 2 , Juan M Llabot 2 , Juan M Irache 5
Bevacizumab-loaded nanoparticles (B-NP) were prepared by a desolvation process followed by freeze-drying, without any chemical, physical or enzymatic cross-linkage.
Compared with typical HSA nanoparticles cross-linked with glutaraldehyde (B-NP-GLU), B-NP displayed a significantly higher mean size (310 nm vs. 180 nm) and a lower negative zeta potential (-15 mV vs. -36 mV). On the contrary, B-NP displayed a high payload of approximately 13% when measured by a specific ELISA, whereas B-NP-GLU presented a very low bevacizumab loading (0.1 μg/mg).
These results could be related to the inactivation of bevacizumab after reacting with glutaraldehyde. From B-NP, bevacizumab was released following an initial burst effect, proceeded by a continuous release of bevacizumab at a rate of 6 μg/h. Cytotoxicity studies in ARPE cells were carried out at a single dose up to 72 h and with repeated doses over a 5-day period. Neither bevacizumab nor B-NP altered cell viability even when repeated doses were used.
Finally, B-NP were labeled with 99mTc and administered as eye drops in rats. 99mTc-B-NP remained in the eye for at least 4 h while 99mTc-HSA was rapidly drained from the administration point. In summary, HSA nanoparticles may be an appropriate candidate for ocular delivery of bevacizumab.