Natural hemostats such as gelatin, collagen and thrombin were first developed as hemostatic agents, followed by mixes and fibrin sealants. More recently, companies have introduced synthetic sealants and hemostats that accelerate the process of blood clotting and provide a stronger seal that will withstand greater pressures. These products employ various synthetic polymer chemistry systems. Glues are required to secure tissue firmly under substantial forces. In extreme cases such as musculoskeletal repair, these glues need to withstand high tension and pressure forces. Fibrin and other sealants are not strong enough for these applications and have been used as adjuncts to sutures and staples. Cyanoacrylate glues have sufficient strength for most procedures but are not yet cleared for use in the majority of internal applications due to toxicity concerns. They also lack sufficient flexibility for use in many procedures.
Efforts are progressing to develop new biomaterials capable of gluing tissues with high strength, low toxicity, and sufficient flexibility to avoid breakage of the bond. In addition, cyanoacrylate manufacturers are examining the possibility of improving cyanoacrylate technology to overcome the existing challenges of toxicity and brittleness. Despite this huge challenge, one or both of these two approaches are likely to establish new products in the next decade. In addition, the evidence of research work suggests it should be possible to create a glue technology that incorporates hemostatic properties to further enhance the role of this technology.
Apart from fibrin-based sealants and cyanoacrylate-based high-strength glues, there are three other main categories of closure/attachment products in use or in development at present: collagen/thrombin combination, polyethylene glycol polymer and albumin cross-linked with glutaraldehyde. (See Report #S190 for status of technology development in the range of sealants and glues alternatives.)
Continued development of fibrin and other sealants is focused on products performing well in multiple respects:
- Ability to close the wound
- Strength of bond
- Speed of curing
- Protection of the wound from infection
- Low surface friction
- Breathability in order to aid healing
- Lack of adverse side effects to skin and internal tissues
- Ease of handling
These are challenging standards in combination, but manufacturers are progressively succeeding in developing products that perform well when judged against many of these parameters.
For more details, see "Worldwide Surgical Sealants, Glues, Wound Closure and Anti-Adhesion Markets, 2010-2017."