Durable, biocompatible and interphases composed of interpenetrating network of alginate and gelatin (A/G) with long shelf-life were produced. Titanium implants were conditioned with acid:peroxide followed by sodium hydroxide (NaOH) etching. Surfaces were grafted with 3-aminopropyl triethoxysilane (APTES) and optimized. It was hypothesized that interpenetrating network of A/G coated on Ti-APTES in the presence of 0.2 M sodium chloride could improve the adhesive strength and create a highly cohesive hydrogel interphase. Optimized A/G ratio and APTES grafting procedure allowed us to reproducibly produce a layer which resulted in a gap-filling, seamless and robust coating that can assume implant shape, maintain morphology and stay intact for a year at room temperature. Especially A/G 1:3 interphase coating (16.41 +/- 0.34 mu m) demonstrated good adhesion (1.28 +/- 0.32 N), water uptake (589% +/- 78), hydrolytic degradation (63 +/- 1%), low initial wettability in simulated body fluid, but demonstrated rapid methylene blue (MB) uptake (80% of drug within 1 h) and burst release (100% of MB within similar to 3 h), and favored osteoblast adhesion and proliferation over time. Furthermore, A/G 1:3 maintained integrity and showed minimal loss of strength over 12 months. Hence, A/G 1:3 interphase showed substantial potential to improve biofunctionality of bioinert implants.