title: Crystallization study and comparative in vitro-in vivo hydrolysis of PLA reinforcement ligament.
abstract: In the present work, the crystallization behavior and in vitro-in vivo hydrolysis rates of PLA absorbable reinforcement ligaments used in orthopaedics for the repair and reinforcement of articulation instabilities were studied. Tensile strength tests showed that this reinforcement ligament has similar mechanical properties to Fascia Latta, which is an allograft sourced from the ilio-tibial band of the human body. The PLA reinforcement ligament is a semicrystalline material with a glass transition temperature around 61 °C and a melting point of ~178 °C. Dynamic crystallization revealed that, although the crystallization rates of the material are slow, they are faster than the often-reported PLA crystallization rates. Mass loss and molecular weight reduction measurements showed that in vitro hydrolysis at 50 °C initially takes place at a slow rate, which gets progressively higher after 30-40 days. As found from SEM micrographs, deterioration of the PLA fibers begins during this time. Furthermore, as found from in vivo hydrolysis in the human body, the PLA reinforcement ligament is fully biocompatible and after 6 months of implantation is completely covered with flesh. However, the observed hydrolysis rate from in vivo studies was slow due to high molecular weight and degree of crystallinity.
authors.affiliation: 2nd Orthopaedic Department, Aristotle University of Thessaloniki, Thessaloniki, Macedonia 54124, Greece; E-Mails:  beslikastheo@in.gr  (T.B.);  jgigis@otenet.gr  (I.G.);  bill.goulios@gmail.gr  (V.G.);  hristofo@med.auth.gr  (J.C.).
authors.forename: Theodore
authors.initials: T
authors.lastname: Beslikas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Gigis
authors.forename: Vasilios
authors.initials: V
authors.lastname: Goulios
authors.forename: John
authors.initials: J
authors.lastname: Christoforides
authors.forename: George Z
authors.initials: GZ
authors.lastname: Papageorgiou
authors.forename: Dimitrios N
authors.initials: DN
authors.lastname: Bikiaris
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use; D003460:Crystallization; D006801:Humans; D006868:Hydrolysis; D007592:Joint Diseases / Q000503:physiopathology / Q000628:therapy; D019344:Lactic Acid / Q000737:chemistry*; D008022:Ligaments / Q000503:physiopathology*; D008422:Materials Testing; D044367:Phase Transition; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D019736:Prostheses and Implants; D013718:Tensile Strength; D044366:Transition Temperature
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)
references.citation: Biomaterials. 1991 May;12(4):433-7
references.pmid: 1909582
references.citation: J Biomater Sci Polym Ed. 2000;11(6):617-32
references.pmid: 10981677
references.citation: J Mater Sci Mater Med. 2005 Aug;16(8):699-707
references.pmid: 15965738
references.citation: Biomacromolecules. 2007 Jul;8(7):2301-10
references.pmid: 17579477
references.citation: Biomacromolecules. 2010 Jan 11;11(1):277-83
references.pmid: 19928814
references.citation: Biomaterials. 1991 Apr;12(3):292-304
references.pmid: 1649646
references.citation: J Oral Maxillofac Surg. 1999 Feb;57(2):113-8
references.pmid: 9973116
references.citation: Biomaterials. 2000 Dec;21(24):2529-43
references.pmid: 11071603
references.citation: Biomaterials. 1992;13(9):594-600
references.pmid: 1391406
references.citation: Biomaterials. 2006 Jul;27(19):3540-8
references.pmid: 16542719
references.citation: J Biomater Sci Polym Ed. 2007;18(5):579-94
references.pmid: 17550660
references.citation: Knee Surg Sports Traumatol Arthrosc. 2008 Jul;16(7):655-60
references.pmid: 18418577
references.citation: Biomaterials. 1995 Mar;16(4):305-11
references.pmid: 7772670
references.citation: Biomacromolecules. 2003 Nov-Dec;4(6):1466-86
references.pmid: 14606869
references.citation: Biomaterials. 1981 Oct;2(4):215-20
references.pmid: 7326315
references.citation: J Mater Sci Mater Med. 2006 Feb;17(2):169-77
references.pmid: 16502250
references.citation: Macromol Biosci. 2004 Feb 20;4(2):100-11
references.pmid: 15468200
references.citation: Biomaterials. 1996 Jan;17(2):93-102
references.pmid: 8624401
references.citation: Langmuir. 2010 Jan 5;26(1):378-83
references.pmid: 20038176
references.citation: Biomaterials. 2001 Feb;22(4):363-9
references.pmid: 11205440
references.citation: Acta Biomater. 2011 May;7(5):2035-46
references.pmid: 21316490
references.citation: Int J Biol Macromol. 1999 Jun-Jul;25(1-3):283-91
references.pmid: 10416676