Tissue-Adhesive Surfaces

Similarly, silk functionahzation of antiadhesive poly(methacrylic acid) brushes on titanium increased cell adhesion, but maintained its antiadhesive properties towards bacteria (Zhang et al., 2008). In some cases, the base material already represents a tissue adhesive surface and creating patches of nonadhesive PEG islands at the right separation distance excludes bacterial adhesion without negative effects on tissue cell adhesion (Wang et al., 2011). 

The extent to which these new tissue adhesives and hemostats will influence surgical procedures can be seen in the following analogy. An effective carpenter cannot create a masterpiece without a saw to cut wood, nails to ensure local fixation of separate pieces of wood, and glue to cause broad surface apposition between wood surfaces. Similarly, the surgeon presently uses a scalpel to cut and divide tissues as well as a suture to create local fixation of tissues, but until... 

This agent was approved by the FDA in May of 2000 and is the first tissue adhesive to be specifically approved for use on lung parenehyma. It is extremely strong and has excellent adherence strength on the surface of the lung. Approval... 

The final section in this volume deals with applications of adhesion science. The applications described include methods by which durable adhesive bonds can be manufactured by the use of appropriate surface preparation (Davis and Venables) to unique methods for composite repair (Lopata et al.) Adhesive applications find their way into the generation of wood products (Dunky and Pizzi) and also find their way into the construction of commercial and military aircraft (Pate). The chapter by Spotnitz et al. shows that adhesion science finds its way into the life sciences in their discussion of tissue adhesives. 

The receptor-like protein tyrosine phosphatases have a transmembrane and, in some cases, a large extracellular domain with a very variable structme (Fig. 8.16). Many, but not all, membrane protein tyrosine phosphatases have two catalytic domains in the cytoplasmic region. The complete structme is very similar to the structure of transmembrane receptors. Understanding of their function is far from complete. Both the natural ligands and the substrate proteins following in the sequence are incompletely characterized. Several studies have demonstrated a role for receptor-like PTPs in neuronal cell adhesion signaling pathways. In cells of the neural tissue, a surface protein, contactin has been identified as ligand for the extracellular domain of a protein tyrosine phosphatase (Peles et al., 1995). 

In this section, we will highlight the use of the grafting technique for designing polymeric biomaterial surfaces that exhibit non-fouling property, selective protein adsorption, enhanced tissue adhesion, and minimum frictional damage to mucosa membranes. 

Adhesives are usually designed to bond dry surfaces as wood and metal, but very specially designed adhesives are formulated for bonding moist tissue surfaces. The human skin is moist and contains sweat glands that allow moisture to permeate the full thickness of the skin. If injured, the subcutaneous tissue hemorrhages because blood vessels are severed. Vessel diameter increases with tissue depth as can be observed in the Fig. 2.1, and any tissue adhesive or protective barrier must be capable of bonding to a moist surface and possibly applied over a bloody field. 

Cardiovascular-functional polymers cover almost all categories of synthetic polymers and large numbers of biopolymers. They are used to build the device bulk, act as surface-modifying additives [SMA], and also formulate tissue adhesives [11-17]. 

Another important example of the diflFerential adhesiveness which protein-dominated surfaces can display, is in the development of artificial skin especially for wound dressings and for temporary covers of extensive burns. C. W. Hall and co-workers 17) showed that relative tissue adhesion to mechanically identical velour fabrics constructed of various materials follows the order predicted by the critical surface tensions of construction material. 

Because a-cyanoacrylates contain a double bond substituted by two electron-withdrawing substituents, they are highly susceptible to anionic initiation, and water is basic enough to initiate very rapid polymerization. Therefore, because moisture can initiate polymerization and because the formed polymer is able to firmly adhere to moist surfaces, it has evoked considerable medical interest as a tissue adhesive (19. 20). 

Remove cap from the instrument. If viewing the cap reveals debris or nonspecific tissue adhesion, the said material may be removed by gently blotting the polymer surface with an adhesive-type notepad (regular adhesive, not super... 

---