Absorbable oxalate polymers

Early demonstration that the absorption of poly(methoxypropyl cyanoacrylate) can be accelerated in the presence of hquid absorbable oxalate polymers led Shalaby to develop a new family of methoxypropyl cyanoacrylate (MFC)/polyester formulations as tissue adhesives with a broad range of properties. These formulations were tailored to produce absorbable tissue adhesives with a range of adhesive properties and compositionally controlled compliance depending on the type and content of the absorbable polyester component in the formulation. 

Absorbable oxalate polymers biological performance of transcortical pins, 208-209... 

An absorbable polymeric modifier that is compatible with the chosen cyanoacrylate to achieve a moderate-to-high preuse viscosity for ease of application, and to increase the absorption rate and compliance of tile cured adhesive for minimizing residence time at the application site and maximizing mechanical biocompatibility — for this, highly absorbable liquid oxalate polymers, such as poly(triox-yethylene oxalate) (PTOEO) and amorphous or low-melting absorbable copolyesters such as those described in Chapter 3 — polyaxial copolyesters and other copolymers based on cyclic monomers — were selected. 

The iron absorption is inhibited in the presence of carbonates, oxalates and phosphates. Probably they participate in macromolecular polymer formation, which are not absorbable from alimentary canal. 

In response to these concerns, and particularly the ones associated with tire nonabsorbable cyanoacrylates that are used clinically. Linden and Shalaby disclosed a novel, absorbable tissue adhesive composition that addressed, to a practical extent, the drawbacks of the absorbable bioadhesive as well as nonabsorbable cyanoacrylates. In effect, these absorbable tissue adhesive compositions were based (1) primarily on methoxyalkyl cyanoacrylates and preferably methoxypropyl cyanoacrylate as the precursor of an absorbable tissue adhesive polymer and (2) on a polymeric, highly absorbable, liquid comprising an oxalate ester of triethylene glycol as a modifier to modulate the viscosity of the overall composition, lower the heat of polymerization, and increase the compliance and absorption rate of the cured adhesive joint. In a more recent disclosure by Shalaby, a number of other useful modifiers were described and the functional performance of the new adhesive compositions was reported. ... 

Based on the design criteria noted above, the evolution of the absorbable cyanoacrylate-based system commenced with methoxypropyl cyanoacrylate (MFC) and was followed by formulation of MFC with polyether oxalate or polyester carbonate. Figure 5.1 outlines a polymerization scheme and designation of the final polymer. Both V-100 and V-150 tissue adhesives contain the same components but in different proportions. 

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