There is an increasing interest in new polymeric systems for various clinical applications, that will be based on known materials, obviating the need for development of new polymers. We have developed dual composite formulations and processing methods for converting natural-based hydrogel networks to biomedical applications. In order to enhance the mechanical- physical properties and functionality, combination of two types of functional materials were added: hemostatic agents and cellulose fibers or hydeoxyapatite. The effects of the formulation parameters and processing conditions on the physical, mechanical and biological properties were elucidated. In-vivo studies were performed as well. Our results show that the addition of functional fillers enabled to increase the tensile strength and modulus of the bulk material, leading to both, higher sealing ability and higher bonding strength. The gelation time and swelling degree significantly decreased and the viscosity increased with the functional fillers incorporation, which all together enables better functioning. We showed that our novel concept of dual-composite hydrogels, combined with appropriate formulation parameters, new processing methods and nano/micro structuring effects, is of great scientific and medical relevance, and is expected to provide new solutions to basic needs in various medical fields.