  Nanoparticles (NPs) based on the polymer poly (lactide-co-glycolide) acid
(PLGA) have been widely studied in developing delivery systems for drugs and
therapeutic biomolecules, due to the biocompatible and biodegradable properties
of the PLGA. In this work, a synthesis method for bone morphogenetic protein
(BMP-2)-loaded PLGA NPs was developed and optimized, in order to carry out and
control the release of BMP-2, based on the double-emulsion
(water/oil/water,W/O/W) solvent evaporation technique. The polymeric surfactant
Pluronic F68 was used in the synthesis procedure, as it is known to have an
effect on the reduction of the size of the NPs, the enhancement of their
stability, and the protection of the encapsulated biomolecule. Spherical solid
polymeric NPs were synthesized, showing a reproducible multimodal size
distribution, with diameters between 100 and 500 nm. This size range appears to
allow the protein to act on the cell surface and at the cytoplasm level. The
effect of carrying BMP-2 co-adsorbed with bovine serum albumin on the NP
surface was analyzed. The colloidal properties of these systems (morphology by
SEM, hydrodynamic size, electrophoretic mobility, temporal stability, protein
encapsulation, and short-term release profile) were studied. The effect of both
BMP2-loaded NPs on the proliferation, migration, and osteogenic differentiation
of mesenchymal stromal cells from human alveolar bone (ABSC) was also analyzed
in vitro.
