Tunable supramolecular hydrogel for in situ encapsulation and sustained release of bioactive lysozyme

To develop new matrices for the entrapment and sustained release of bioactive lysozyme, a series of supramolecular hydrogels based on α-cyclodextrin (α-CD) and water-soluble poly(ε-caprolactone)–poly(ethylene glycol) block copolymer (PCL-b-PEG) were prepared in the presence of chicken egg lysozyme. Different from commonly used polymeric microspheres and chemically crosslinked hydrogels for lysozyme encapsulation, such hydrogel matrices could be formed under mild conditions without high temperature and the use of chemical emulsifiers or crosslinkers. Their gelation rate, mechanical strength and shear viscosity as well as the release behavior for the encapsulated lysozyme could be tuned easily by the change of α-CD or PCL-b-PEG amount. For the encapsulated lysozyme, its conformation and biological activity could be well maintained when compared to native lysozyme. For the resultant supramolecular hydrogels, they were also confirmed to have a good biocompatibility by MTT assay using mice skin fibroblast (L929).

In an aqueous environment, the supramolecular gelation and lysozyme loading can be achieved simultaneously at room temperature without chemical emulsifiers or crosslinkers.Figure optionsDownload high-quality image (48 K)Download as PowerPoint slideHighlights
► Novel supramolecular gelation strategy for in situ encapsulation and sustained release of bioactive lysozyme was developed.
► The supramolecular gelation and lysozyme loading could be achieved simultaneously in an aqueous environment.
► The gelation rate and extent during lysozyme encapsulation as well as the release behavior of encapsulated lysozyme could be easily tuned.
► For the encapsulated lysozyme, its conformation and biological activity could be well maintained.