Sinteza i dizajniranje strukture i osobina hidroksiapatit-polilaktid kompozitnih biomaterijala
Synthesis and designing of the structure and properties of composite biomaterials hydroxyapatite-polylactides
Author
Ignjatović, Nenad L.
Mentor
Plavšić, MilenkoCommittee members
Uskoković, Dragan
Aleksić, Radoslav
Jovanović, Slobodan
Savić, Vojin
Metadata
Show full item recordAbstract
Koštani defekti mogu se reparisati biomaterijalima na bazi sintetskog hidroksiapatita
(HAp). U slučaju reparacije koštanih defekata sa prekidom kontinuiteta, neophodno je da
upotrebljeni biomaterijal zadovolji biomehaničke uslove. Poboljšanje mehaničkih osobina HApa
ostvareno je njegovim ojačavanjem biokompatibilnim pofimerima.
Predmet ovih istraživanja je sinteza i dizajniranje strukture i osobina kompozitnih
biomaterijala hidroksiapatit-polilaktida. Upotrebom bioresorbilnog poli-l-laktida (PLLA) i
bioneresorbilnog HAp-a dobijen je kompozitni biomaterijal HAp/PLLA sa mehaničkim
osobinama bliskim prirodnom koštanom tkivu. Mešanjem potpuno rastvorenog PLLA sa
komponentom HAp-a, a zatim vakuum uparavanjem, dobijen je visoko porozni kompozit. Ova
vrsta kompozita je naknadno dizajnirana hladnim i toplim presovanjem. U ovim istraživanjima
ispitan je uticaj presovanja na degradacione promene tokom kompaktiranja, molsku masu
PLLA i kompresionu čvrstoću. Definisan je uticaj parametara presovan...ja, kao što su
temperatura, pritisak i vreme na poroznost, kompresionu čvrstoću i modul elastičnosti. Ispitan
je uticaj veličina čestica HAp-a i molske mase PLLA na analizirane osobine. Mogućnosti
primene kompozitnog biomaterijala HAp/PLLA u realnim, in vivo uslovima ispitane su
primenom FT-IR spektroskopije. Tokom procesa primene dolazi do formiranja novog vezivnog
tkiva kolagena, uz stvaranje novih kolagenskih grupa koje su registrovane FT-IR
spektroskopijom. Implanti od HAp/PLLA kompozita intraperitonealno su implantirani. a nakon
2, 7 i 12 nedelja od impfantacije histopatološki analizirani. Mogućnosti zamene, do sada široko
korišćene, primene autologne kosti u reparacijama koštanog tkiva, takođe je analizirana u ovoj
doktorskoj disertaciji.
Bone-defects can be repaired using biomaterials based on synthetic calciumhydroxyapatite
(HAp). The bone tissue repair, in the case of broken bone continuity,
can successfully be made by a biomaterial of corresponding mechanical properties.
Adequate mechanical properties of biocomposite blocks can be reached by reinforcing
HAp with biocompatible polymers.
The research subject of this study are the synthesis and designing of the structure and
properties of composite biomaterials hydroxyapatite-polylactides Using biocompatible
and bioresorptive poly-L-lactide (PLLA) polymer, HAp/PLLA composite biomaterial
consisting of a non-bioresorptive HAp and bioresorptive PLLA component with
mechanical properties similar to those of bones can be produced. Completely dissolved
PLLA with HAp granules gives a mixture, from which, after evaporation in vacuum,
HAp/PLLA composite biomaterial of high porosity is formed. The material obtained in
this way can be compacted by hot and cold pressing. In order t...o investigate the
influence of hot pressing time on the degradation changes, the molecular weight of
PLLA and compressive strength of biocomposite before and after hot pressing have
been analyzed. The effects of hot pressing parameters such as temperature, pressure
and time, on the porosity, compressive strength, elasticity modulus and the mechanism
of fracture formation of hot pressed blocks have been investigated, as well as their
dependence on the HAp particle sizes and PLLA molecular weights. In this research
the bone tissue repair process in vivo using HAp/PLLA composite biomaterial was
studied by FT-IR spectroscopy. Implants made of HAp/PLLA biocomposites with PLLA
were studied 2, 7 and 12 weeks after being implanted intraperitoneally. Also, a possible
substitution of the autologous bone with HAp/PLLA biocomposites, in filling up bone
defects, was investigated.