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Being a major component of bone tissue, hydroxyapatite is the most investigated calcium phosphate in the design and development of bone implants. The high brittleness and poor load-bearing properties have led researchers to manipulate hydroxyapatite performance by applying polymer or metal materials. The present study focuses on biomimetic approach of the hydroxyapatite synthesis from the cuttlefish bone in order to preserve highly porous structure. The low stiffness of hydroxyapatite scaffold was altered by thin polycaprolactone/poly(lactic acid) coating, resulting in remarkably 18-fold increase of Young's modulus. The mechanical test revealed that poly(lactic acid) increases the stiffness of composite scaffolds which depends on the polycaprolactone/poly(lactic acid) volume ratio. The composite scaffolds are bioactive supporting the deposition of new calcium phosphates when incubated in simulated physiological medium for 21 days. Moreover, the culture of human embryonic kidney cells indicated non-cytotoxicity of the composite scaffolds with emphasis on the cell proliferation during three days of culture. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018.

Highly porous hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2 , HAp) catalyst support was prepared through hydrothermal transformation of aragonitic cuttlefish bone (Sepia Officinalis, L., Adriatic Sea) at 200°C, preserving the natural well interconnected porous structure. To deposit the TiO 2 catalyst on the pore walls of the HAp support two methods were used: i) vacuum impregnation of the support with the suspension of a commercial TiO 2 nanopowder in isopropanol and ii) in situ synthesis of TiO 2 on the support by sol-gel technique. XRD analysis and FTIR spectroscopy were used to determine the phase composition of the material. The morphology and microstructure of the composite samples were studied by scanning electron microscopy (SEM). The presence of TiO 2 particles on the HAp surface was determined by SEM/EDX analysis. To determine the specific surface area and pore size, Brunauer-Emmett-Teller (BET) method was used. The results of the BET method showed the increased specific surface area and pore size reduction after impregnation of TiO 2 into the HAp carrier. The photocatalytic activity of HAp/TiO 2 samples was studied in a batch reactor with an annular UV-A lamp using salicylic acid as a model water pollutant. The results indicated the suitability of prepared HAp supported TiO 2 catalysts for photocatalytic applications.