Hydroxyapatite (HAp) coatings were applied using sol-gel method. Phosphor pentoxide and calcium nitrate were used as phosphorous and calcium precursors, respectively. Zinc nitrate and silver nitrate were used as substitute of calcium in HAp structure. As a base concentration, 1.5 wt %Ag and 2.5 wt %Zn were used. The weight percent of Ag was increased at 0.3 wt% and Zn content was scaled down at 0.5 wt%. Phase analysis and chemical bonds of synthesized materials were studied by XRD and FTIR. Antibacterial activity of Ag- and Zn-doped samples against methicilin-resistant Staphylococcus aureus (MRSA) were assessed by the plate-counting method. The XRD and FTIR results proved formation of HAp compound. Colony counting showed that silver and zinc ions prevent proliferation and growth of MRSA. Interestingly, co-presence of metal ions improves the antibacterial effectiveness of the coatings and the combined effect was greater than sum of the individual effects when each was administered alone. Overall, synergism between antibacterial activities of Zn(2+) and Ag(+) ions against MRSA can be suggested. Thus, cell toxicity decreases and biocompatibility increases without any decrement in antibacterial activity.

Cellulose powder was oxidized by NO2 gas and the porous scaffold was fabricated by dry pressing. RGD peptide was immobilized on the surface of scaffold by grafting to make a hybrid scaffold. The hybrid scaffold was characterized by SEM and FTIR and its biocompatibility was examined through MTT assay. FTIR results proved oxidization of cellulose and bonding between scaffold surface and RGD. Porous microstructure having suitable size was confirmed by SEM. The results by MTT showed significant increase of viable cells on hybrid scaffold. Porous structure and high biocompatibility were the benefits of scaffold in bone tissue engineering.