Organic–inorganic collagen/iota‐carrageenan/hydroxyapatite hybrid membranes are bioactive materials for bone regeneration

ABSTRACT This study aimed to produce biomembranes with controlled degradability for application in bone regeneration in order to stimulate biological reactions necessary to improve bone formation. Hydrogels were prepared by dissolving hydrolyzed collagen (HC) and iota‐carrageenan (ι‐Carr) in aqueous mixtures containing CaCl2 and H3PO4. A rise in pH by exposure to NH3(g) caused mineral precipitation into the hydrogel. Subsequently, the membranes were fabricated by solvent casting. Infrared spectroscopy and X‐ray diffraction attested hydroxyapatite formation. The crystallite size was close to 12 nm, which was smaller than the size reported for human bone apatite. The membranes induced bone‐like apatite precipitation in simulated body fluid. The carrageenan content modulated the membrane mechanical behavior. Membranes with controlled degradability were obtained by using higher amount of this polysaccharide. These membranes were able to release HC in physiological conditions. The surface properties were evaluated in terms of wettability and surface energy (γS) by means of contact angle (θc) measurements. Low θc (8.5–16.8) indicated that the hybrid membranes were hydrophilic, while higher γS values, around 70.6 mJ.m−2, could favor biomolecule incorporation into the surface. Our data set evidenced that these materials could potentially be used as a temporary guided tissue regeneration membrane with the possibility of inducing bone regeneration. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48004. Calcium and phosphate ions can be entrapped into the interstices of polysaccharide/collagen membranes resulting in the controlled precipitation of biominerals.