In Situ Agar – Carbomer Hydrogel Polycondensation:a Chemical Approach to Regenerative Medicine

Injectable hydrogels with in situ polycondensation capability are believed powerful tools to be used in spinal cord injury (SCI) repair: they can be injected using minimally invasive techniques and can conform to any shape. Here, we finely tuned chemistry of a promising hydrogel, specifically developed for cell and drug delivery purposes in SCI therapeutical strategies, in order to allow its injection through a 40 mm needle at solution state and to let gelation take place inside target tissue, just after injection. A solution was injected in vivo into mouse spinal cord and consequent in situ gel formation was verified: magnetic resonance imaging showed presence of the polymeric network at injection site and histological analysis, coherently, revealed spherical enclosures in spinal cord. This hydrogel showed to be a new biocompatible and microinvasive tool that can be used in vivo as local reservoir for in situ delivery of drugs and cells. This paves the way for the future generation and in vivo experimental validation of new combined tissue engineering approaches