Biocompatible adhesive

The concentration of a small molecule reactant inside the polymer coils can be lower than outside when one uses a poor solvent for the polymer. This results in lower local and overall reaction rates. In the extreme, a poor solvent results in reaction occurring only on the surfaces of a polymer. Surface reactions are advantageous for applications requiring modification of surface properties without affecting the bulk physical properties of a polymer, such as modification of surface dyeability, biocompatibility, adhesive and frictional behavior, and coatability [Ward and McCarthy, 1989]. 

Toxicity and biocompatibility. Adhesives used in medical devices that are implanted or in contact with the body must be tested and shown to be non-toxic, biologically inert, and compatible withblood andbody fluids. Compatibility with blood and other body fluids is especially critical. Surfaces in contact with blood must not serve a sites for coagulation and clotting of blood. Generally, qualification testing is performed to ISO-10993[ ] or to U. S. Pharmacopoeia (USP) Class VI. The two standards specify slightly different tests. The USP Class VI standard specifies acute... 

Biomolecular materials and processes have in the recent decade overlapped with polymer science and engineering. Advancements in polymeric materials research for biomolecular and medical applications are rapidly becoming commercialized, examples include biocompatible adhesives for sutureless tissue bonding, liquid dressings for wounds and many other materials used for in vitro and in vivo medical applications. To keep pace with these advancements, the editor has included useful terms in the main body that are commonly used in the material sciences for these new industries. 

Modification of surfaces with thin polymer films can be used to tailor the surface properties such as hydrophilicity/phobicity, biocompatibility, adhesion, adsorption, corrosion resistance, and friction. ° " ° Nanoscale organization of the functional surface can be directed by photolithography and micro-and nanoscale printing. The chemical nature of the underlying material becomes hidden by the presence of a film a few nm thick. The interaction of the whole system with the surrounding environment is governed by these coatings. 

The term biocompatible adhesive includes any natural or synthetic adhesive that interfaces with living tissues and biological fluids, and is suitable for short-/long-term biomedical applications. These surgical glues are particularly useful as replacement or support for sutures that are sometimes difficult to manipulate during laparoscopic or microscopic procedures, or... 

A surface is that part of an object which is in direct contact with its environment and hence, is most affected by it. The surface properties of solid organic polymers have a strong impact on many, if not most, of their apphcations. The properties and structure of these surfaces are, therefore, of utmost importance. The chemical stmcture and thermodynamic state of polymer surfaces are important factors that determine many of their practical characteristics. Examples of properties affected by polymer surface stmcture include adhesion, wettability, friction, coatability, permeability, dyeabil-ity, gloss, corrosion, surface electrostatic charging, cellular recognition, and biocompatibility. Interfacial characteristics of polymer systems control the domain size and the stability of polymer-polymer dispersions, adhesive strength of laminates and composites, cohesive strength of polymer blends, mechanical properties of adhesive joints, etc. 

Schiraldi et al. [64] have developed this kind of material by combining silica particles and pHEMA. pHEMA is a biocompatible hydrogel that has been widely studied in the past decades due to its chemical-physical structure and mechanical properties. It has been widely used in ophthalmic prostheses (contact or intraocular lenses), vascular prostheses, drug delivery systems and soft-tissue replacement [65]. These authors have shown that by incorporating silica nanoparticles, the resulting hybrid material is highly biocompatible and promotes bone cell adhesion and proliferation of bone cells seeded on it.1 ... 

Many kinds of nonbiodegradable vinyl-type hydrophilic polymers were also used in combination with aliphatic polyesters to prepare amphiphilic block copolymers. Two typical examples of the vinyl-polymers used are poly(/V-isopropylacrylamide) (PNIPAAm) [149-152] and poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) [153]. PNIPAAm is well known as a temperature-responsive polymer and has been used in biomedicine to provide smart materials. Temperature-responsive nanoparticles or polymer micelles could be prepared using PNIPAAm-6-PLA block copolymers [149-152]. PMPC is also a well-known biocompatible polymer that suppresses protein adsorption and platelet adhesion, and has been used as the hydrophilic outer shell of polymer micelles consisting of a block copolymer of PMPC -co-PLA [153]. Many other vinyl-type polymers used for PLA-based amphiphilic block copolymers were also introduced in a recent review [16]. 

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