Tailored hyaluronic acid hydrogels through hydrophilic prepolymer cross-linkers

• DOI: 10.1039/b917113d
• Publication Date: 2009-12-02T12:01:43Z
• Authors: Anandhan Dhanasingh; Jochen Salber; Martin Moeller; Juergen Groll
• Keywords: Prepolymer; Isocyanate

Despite its enormous biological importance, a lack of mechanical stability and fast degradability often hampers more intense application hyaluronic acid (HA) for biomedical applications. We present method to prepare based hydrogels with tailored stability, porosity by cross-linking functional 18 kDa six arm star shaped poly(ethylene oxide-stat-propylene oxide) (sP(EO-stat-PO)) prepoylmers in aqueous solutions. In the case NCO groups at distal ends arms, occurs through reaction OH HA resulting urethane bridges between molecules HA. parallel, slow hydrolysis isocyanates amines that subsequently rapidly aminolyze other isocyanate lead urea prepolymers as side reaction. Overall, this process leads within 5 15 min depending on molar ratios NCO-sP(EO-stat-PO) A chemically orthogonal way can be achieved acrylate thiolated where exclusively results from Michael-type addition thiol groups. This also gelation times min. The two mechanisms are compared gels analyzed regarding chemical composition, equilibrium water content, degree sol-content, porosity, resistance towards enzymatic degradation hyaluronidase.