Gelatin-Alginate hydrogels as bioadhesives, drug delivery systems and scaffolds for tissue engineering

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. Gelatin, a natural water-soluble polymer derived from collagen, and alginate, a natural polysaccharide extracted from marine algae, are both biocompatible, biodegradable, and have been used in variety of biomedical application. When these polymers are crosslinked using a zero-length carbodiimide crosslinker, unique dual polymeric network structures are created. We have developed several processing methods for converting these gelatin-alginate networks to biomedical applications and studied the effects of the formulation parameters and processing conditions on the physical, mechanical and biological properties. In-vivo studies were performed as well. Examples demonstrating several applications will be presented.

Adhesives for wound closure and medical sealant applications will focus on controlling the cohesion/adhesion mechanism for achieving desired bonding and sealing abilities, as well as relevant physical properties, such as viscosity, gelation time and swelling degree. Incorporation of hemostatic agents and reinforcing short fibers resulted in novel dual composite structures. Their structuring enables optimal functioning in bleeding control for life saving applications.

Drug delivery applications will focus on the hydrogels as vehicles for antibiotic eluting systems, such as for treating infections of the periodontal pockets. In these systems, although the alginate concentration used is relatively low, it strongly affected both, the physical and mechanical properties of the hydrogel.

Scaffolds for tissue regeneration applications will focus on novel porous structures. Special formulations are designed to be injected through long and narrow catheters in order to reach areas in the body that are difficult to reach. This minimally invasive procedure reduces the patient discomfort, risk of infection, and hospitalization time. Other formulations are designed to combine resilience with low modulus, for adipose tissue regeneration. These present a new approach for breast reconstruction following partial mastectomy due to breast cancer diagnosis.

In all mentioned above gelatin-alginate systems, we showed that combination of appropriate formulation parameters with new processing methods and structuring effects, are of great scientific and medical relevance, and is expected to provide new solutions to basic needs in various medical fields.