Bioabsorbables polymers Implants

Polydioxanone (PDS) is completely elirninated from the body upon absorption. The mechanism of polydioxanone degradation is similar to that observed for other synthetic bioabsorbable polymers. Polydioxanone degradation in vitro was affected by gamma irradiation dosage but not substantially by the presence of enzymes (39). The strength loss and absorption of braided PDS, but not monofilament PDS, implanted in infected wounds, however, was significantly greater than in noninfected wounds. 

M.W.King,Y.Marois,G.R.Marinov,J.P.Delagoutte and R.Guidoin, Monitoring the inflammatory response and rate of resorption of partially resorbable bicomponent fibers. Proceedings of ASTM Symposium on Synthetic Bioabsorbable Polymers for Implants, Kansas City, MO, USA, 16-17 Nov. 1999, p. 8. 

A second application is the controlled release of the polymer. Here, we report two different examples. The first example is a bioabsorbable suture. A suture is defined as bioabsorbable in solid polymeric materials or devices if it can dissolve in body fluids without any polymer chain cleavage or molecular mass decrease. Another example is a water-soluble implant that undergoes slow dissolution in body fluids. A bioabsorbable polymer also can be bioresorbable if the dispersed macromolecules are excreted [6]), or it is a MD belonging at least to class 11b [4] but usually to class 111 (release a drug with an ancillary function or it is completely resorbable) [5],... 

K. Gorona, S. Gogolewski, Novel biodegradable polyurethanes for medical applications, in Synthetic Bioabsorbable Polymers for Implants, ed. by C.M. Agrawal, J.E. Parr, S.T. Lin (ASTM special technical publication, UK, 2000), pp. 39-57... 

Bioabsotbable ate solid polymeric materials or devices, which can dissolve in body fluids without any polymer chain cleavage or molecular mass decrease. For example, it is the case of slow dissolution of water-soluble implants in body fluids. A bioabsorbable polymer can be bioresorbable if the dispersed macromolecules are excreted. 

Sinha, V.R. and Khosla, L. (1998) Bioabsorbable polymers for implantable therapeutic systems. Drug Dev. Ind. Pharm. 24, 1129-1138. 

Marois Y, Zhang Z, Vert M, Deng X, Lenz RW, Guidoin R (2000) In Mauli Agrawal C, Parr JE, Lin ST (eds) Synthetic bioabsorbable polymers for implants. American Society for Testing and Materials, West Conshohocken, p 12... 

There is an important additional advantage of using (n-s) polymer-CD-ICs to nucleate the melt-crystallization of polymers. Because CDs are nontoxic, biocompatible, and biodegradable, they may be safely utilized in (n-s) polymer-CD-IC nucleants to fabricate both permanent and biodegradable/bioabsorbable implants that are also nontoxic. 

The size of the cartilage formed in the experimental bioabsorbable implants increased over a period of about 7 weeks after which time it remained stable. The growth appeared histologically to be at the expense of the fibrous tissue initially seen and associated at least temporally with a decrease in neovascularization and resolution of the mild inflammatory response originally noted. There was a decrease in inflammatory response, as evidenced by decreases in the number of polymorphonuclear leukocytes and giant cells, which correlated with the disappearance of the polymers. Very little evidence of either inflammatory response or polymer remnants were seen after 7 weeks when using bioabsorbable material, while moderate inflammation and minimal cartilage formation was noted in the nonabsorbable implants after this period of time. 

To be used as biomaterials, polymers must possess biocompatibility, bioabsorbability and mechanical resistance [114]. Current applications include surgical implants and plain membranes in vascular or orthopaedic surgery, as well as the controlled release of drugs. PLA is the most widely used material for medical applications. Other possible outlets are offered by the hygiene sector including, nappy back sheets, cotton swabs, disposable razors and so on. 

Bioabsorbables These polymers can be dissolved in body fluids with minimal change to their original molecular weight. These polymers are mainly used as slow water-soluble implants... 

In addition, polyanhydrides have been considered as attractive materials for temporary biomaterials, such as sutures, and bioabsorbable prostheses. Degradation products of these polymers have anti-thrombotic/anti-inflammatory properties. Active polymers namely poly(anhydride esters) stimulate new tissue formation. The resulting combination features make polyanhydrides as ideal implantable materials. 

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