ap9b00139_si_001.pdf (601.32 kB)
Cross-Reactive Alginate Derivatives for the Production of Dual Ionic–Covalent Hydrogel Microspheres Presenting Tunable Properties for Cell Microencapsulation
journal contribution
posted on 2019-05-02, 00:00 authored by Luca Szabó, Carmen Gonelle-Gispert, Elisa Montanari, François Noverraz, Aurélien Bornet, Léo H. Bühler, Sandrine Gerber-LemaireThe
production of hydrogel micropsheres (MS) presenting physical,
mechanical, and biological properties which can be modulated by their
chemical composition is required to enlarge the panel of biomaterials
for cell transplantation therapies. Functionalization of sodium alginate
(Na-alg) with cross-reactive poly(ethylene glycol) (PEG) derivatives
presenting terminal thiol and carbon electrophile functionalities
provided novel polymers which upon simple one-step protocol formed
hydrogel MS assembled by combination of Ca-alg interactions and sulfur–carbon
covalent bonds. Several parameters such as the grafting degree on
the alg backbone and the viscosity of the polymer solutions can be
adjusted to provide optimal formulation for the capsule formation
technology. Compared with pure Ca-alg MS, dual ionic–covalent
MS displayed improved mechanical resistance and shape recovery performance.
Importantly, under conditions which resulted in complete liquefaction
of Ca-alg MS, chemically cross-linked Alg-PEG MS maintained stable
spherical morphology. In addition, these hydrogels allowed excellent
viability and functionality of microencapsulated Huh7 cells. After
transplantation in the peritoneal cavity of immune competent mice,
the dual ionic–covalent MS remained free-floating and maintained
their integrity over 30 days.