Encapsulation of BSA in hybrid PEG hydrogels: stability and controlled release

Hybrid hydrogels based on silylated polyethylene glycol, Si-PEG, were evaluated as hybrid matrices able to trap, stabilize and release bovine serum albumin (BSA) in a controlled manner. Parameters of the inorganic condensation reaction leading to a siloxane (Si-O-Si) three dimensional network were carefully investigated, in particular the temperature, the surrounding hygrometry and the Si-PEG concentration. The resulting hydrogel structural features affected the stability, swelling, and mechanical properties of the network, leading to different protein release profiles. Elongated polymer assemblies were observed, the length of which ranged from 150 nm to over 5 mu m. The length could be correlated to the Si-O-Si condensation rate from 60% (hydrogels obtained at 24 degrees C) to about 90% (xerogels obtained at 24 degrees C), respectively. Consequently, the controlled release of BSA could be achieved from hours to several weeks, with respect to the fibers' length and the condensation rate. The protein stability was evaluated by means of a thermal study. The main results gave insight into the biomolecule structure preservation during polymerisation, with Delta G < 0 for encapsulated BSA in any conditions, below the melting temperature (65 degrees C).

Automated summary

Hybrid hydrogels based on silylated polyethylene glycol (Si-PEG) were evaluated as matrices for controlled release of bovine serum albumin (BSA), with investigations into the parameters affecting the hydrogel structure and protein release behavior. The study provided insights into the stability, swelling, and mechanical properties of the network, as well as the impact of different factors on the protein release profiles.