Characterization of structurally related adenovirus-laden silk-elastinlike hydrogels

Genetically engineered silk-elastinlike protein polymer (SELP) analogs, SELP-47K and -415 K, consisting of varying ratio(s) and length(s) of silk and elastin in their monomer repeats and capable of spontaneous hydrogel formation were evaluated as matrices for controlled adenoviral release in vitro. The degree of swelling (q) and the amount of soluble fraction of SELP hydrogel analogs were evaluated with and without the incorporation of adenoviruses. The results indicate that polymer concentration and structure and not the incorporated adenoviruses are the predominant factors that influence q and the soluble fraction in these hydrogels over a 28-day period. The release of adenoviruses was a function of polymer concentration and structure. The higher cumulative percentage release observed in SELP-415K compared to SELP-47K can be attributed to the longer elastin sequence in the polymer backbone. These results indicate the potential of customizing the network properties and release from SELPs by manipulating the macromolecular architecture using recombinant synthesis.