Suture resorbable

Health Safety. PET fibers pose no health risk to humans or animals. Eibers have been used extensively iu textiles with no adverse physiological effects from prolonged skin contact. PET has been approved by the U.S. Eood and Dmg Administration for food packagiug and botties. PET is considered biologically iuert and has been widely used iu medical iaserts such as vascular implants and artificial blood vessels, artificial bone, and eye sutures (19). Other polyester homopolymers including polylactide and polyglycoHde are used iu resorbable sutures (19,47). 

Resulting poly(a-hydroxyacids) are important biomaterials used as resorbable sutures and prostheses [196]. The mechanism of polymerization is not well established. Polymerization may be initiated with Lewis acids (SbF3, ZnCl2, SnCl4) however, other typical cationic initiators (e.g, triethyloxonium or triphenylcarbenium salts) fail to initiate polymerization [197]. Thus, it is not clear whether polymerization proceeds by typical cationic mechanism or rather involves the coordination mechanism. The chain transfer to polymer resulting in transesterification was postulated [198,199] and confirmed later by detailed, 3C NMR studies of lactide copolymers [200]. 

But the different degradation processes, PHB catalyzed by enzymes and acid-base catalyst and PLA just by acid-base catalyst, determine to a considerable extent the degradation and/or resorption times of both materials and therefore the areas for human and veterinary medical use. These materials are used in human or veterinary medicine, or they are presently being tested in the in vitro phase, for example, as resorbable sutures, for blood vessel repair, drug-delivery systems, bandages, scaffolds for producing retard materials for coupling active substances, cells and... 

The physical properties of a biomateiial include mechanical properties, such as stiffness, strength, and durability, together with other properties, such as oxygen permeability. The properties need to be suitable for the intended lifetime of the implant, which can range from the few weeks required for resorbable sutures to the lifetime of the patient receiving a hip replacement. 

Biocompatible plastics are used in medicinal applications, and the prefix bio indicates that the polymer, when being immersed in a Uving organism (human or animal), does not harm the body or its metabolism in any way. These biopolymers can also be based on fossil raw materials or on renewable resources. They may be durable in the body, as in the case of artificial blood vessels, or they may disintegrate and be resorbed in the body, as in the case of resorbable suture threads. 

Although PLA fibres are used in different textile applications as, for example, non-woven textile for clothes, they achieved their first commercial success as resorbable sutures. One of the first commercially available fibre-formed bioresorbable medical products is based on copolymers of GA in combination with L-lactide (Vicryl) [67]. Fibres can be produced both by solvent and by melt-spinning processes and drawn under different conditions to orient the macro molecules [7]. 

Suture materials need to be tested for tensile behavior, that is, ultimate breaking force (N) and extension at break (%), flexibility, creep and resistance to iatrogenic trauma, that is, the suture s ability to withstand mishandling and trauma caused by needle holders during surgery. In the case of resorbable sutures, the rate of biodegradability or resorption also needs to be measured in terms of the rate of strength loss and the rate of mass loss. These two properties do not follow the same decay curve. 

However, since the Tg remains well above room temperature, a plot of varying frequency from 0.001 to 100 Hz of these materials will continue to show little or no change in the storage or loss modulus. The glass transition temperature for chitosan is reported to be 102°C (375°K) (Khachatoorian et al., 2004).This means that resorbable sutures made from chitosan will also be stable at physiological body temperature. 

The approval by the Food and Dmg Administration (FDA) for the use of PCL as dmg delivery carrier and long-term implants (Schantz et al., 2003a,b, 2006) is another key advantage of this material that propelled it faster towards mass production. One very important fact for industry in particular is that PCL has the lowest price on the market if compared with the other bioresorbable and biocompadble polyesters (Armani and Liu, 2000). Companies such as Ethicon, Inc. (Somerville, NJ) started producing PCL resorbable sutures under the trade name Monacryl (Middleton and Tipton, 2000) while others focused more on manufacturing different PCL scaffolds for medical or research purposes (Abedalwafa et al., 2013). 

Developments in the u.se of biodegradable polymers in biomedical and surgical applications are reviewed. Applications discussed include tissue engineering, bone fracture fixation devices, resorbable sutures, vascular grafts, temporary barriers for the prevention of postoperative adhesion, artificial skin and systems for controlled drug release. 92 refs. 

On account of their controlled resorption rate and biocompatibility, POEs have been explored mainly as drug delivery vehicles. Their use as tissue engineering scaffolds is limited due to their weak mechanical properties. There are no reports in the literature for their use as resorbable suture materials. 

PLA is a biodegradable, bioresorbable polymer fiiat can be assimilated by the body and has important applications in sustained-release drug delivery systems. The mechanical properties and absorbability of PLA make it an ideal candidate for implants in bone and soft tissue and for resorbable sutures. 

This polymer has been used in several medical applications already approved by the U.S. Food and Drug Administration. Recently, PCL is being applied not only in the development of drug delivery systems [42] and resorbable sutures [43], but also as a material for tissue regeneration [44]. 

PLA is a biodegradable polymer that has been widely studied and is used for domestic packaging, and biomedical apphcations, such as resorbable sutures, surgical implants, scaffolds for tissue engineering and controlled dmg-deliveiy devices. PLA can exist as two stereoisomers, designated as D and L, or as a racemic mixture, designated as DL. The D and L forms are optically active while the DL form is optically inactive. Poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) are semicrystalline,... 

Biodegradable synthetic polymers such as poly(glycolic acid), poly(lactic acid) and their copolymers, and copolymers of trimethylene carbonate and glycolide have been used in a number of clinical applications [26-30]. The major applications include resorbable sutures, drug delivery systems and orthopaedic fixation devices such as pins, rods and screws [31, 32]. 

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