Alginate capsules with cuttlebone-derived fillers as an integrated solution for bone repair

Abstract

Alginate capsules with cuttlebone-derived fillers were developed for bone repair applications. Prepared capsules were designed to be suitable for the treatment of small-sized bone loss provocative diseases, such as endodontic and periodontal diseases. Cuttlebone microparticles, as a source of calcium carbonate, or cuttlebone-derived hydroxyapatite microparticles were used as mineral fillers for the preparation of alginate capsules. The capsules were additionally covered with chitosan layer for the hard structure formation and improvement of adhesive properties. Encapsulation efficiency of dexamethasone as a model allopathic drug was 19 %, 24 % and 12 % for capsules with cuttlebone microparticles, capsules with cuttlebone-derived hydroxyapatite and capsules without any mineral filler (control group), respectively. We observed that chitosan coating and lyophilisation contributed for the preservation of spherical structure of alginate capsules with mineral fillers. Swelling study of dried capsules in simulated physiological environment (in phosphate buffer saline, pH = 7.2 at 37 °C temperature) showed that average swelling index of alginate-based capsules without mineral fillers was much higher in comparison to capsules with cuttlebone fillers: 121 %, 17 % and 3 % for control group, capsules with cuttlebone microparticles and capsules with cuttlebone-derived hydroxyapatite, respectively.