In vitro and in vivo study of naturally derived alginate/hydroxyapatite bio composite scaffolds

Biogenic bioceramics scaffolds are receiving considerable attention for bone restoration applications. Compared with scaffolds of chemical origin, biogenic scaffolds exhibit greater biocompatibility and enhanced bioactive features. In the present study, porous biogenic hydroxyapatite (bHA) was prepared via a polymeric infiltration route and was subsequently coated with alginate to produce alginate/biogenic hydroxyapatite (Alg/bHA) composites. Alginate was used to enhance the mechanical properties as well as the bioactivity and biodegradability of the HA scaffolds. A coating of 3%w/v alginate applied for 10 min was found to result in the best coating for the HA porous scaffolds. The in vitro study demonstrated that the prepared composites had acceptable bioactivity and biodegradability characteristics. The histological study in femur bone of rats indicated that the 3Alg/HA scaffolds capable of supporting both endochondral and intramembranous bone formation. The defect was fully regenerated and mostly filled with the mature lamellar bone after 6 months, with Ca/P atomic ratio similar to the rat's normal bone. The studied scaffolds provide a promising therapeutic option to enhance local bone healing because they do not damage liver or kidney functions and do not induce carcinogenic or inflammatory effects. Accordingly, 3Alg/HA scaffolds are recommended for the tissue engineering applications.