Vol. 10, No 3, 2003 pp. 131 - 134
UC 615.46:612.753
CHANGES OF HAp/PLLA BIOCOMPOSITES AND
TISSUE REACTION
AFTER SUBCUTANEOUS IMPLANTATION
S. Najman1, Lj. Đorđević1,
V. Savić1, N. Ignjatović2,
M. Plavšić3, D. Uskoković2
1 Institute of Biomedical Research,
Medical Faculty, Niš, Serbia
2 Institute of Technical Science, SANU,
Belgrade, Serbia
3 Faculty of Technology, Belgrade,
Serbia
Summary. Experimental and clinical studies have shown that HAp granules
and powder may be successfully applied in reconstruction of bone defects.
Composite HAp/PLLA biomaterial embodies good characteristics of each of
these biomaterials. Differences in porosity, microstructure, compressive
consistency as well as in bioresorbility of HAp/PLLA are achieved by using
PLLA of different mole masses. The aim of this study was to analyse light
microscopy of the tissue reaction and changes of implants made of combination
of syngeneic bone fragments and HAp/PLLA biocomposites with PLLA molecule
mass of 430 000 (HP2) and 50 000 (HP3). The mice were divided into 4 experimental
studies, 8 animals each. Two groups underwent implantation, one group of
mice was falsely operated, and one group was used for general control.
Pathohistological analysis of implants was performed three months after
subcutaneous implantation. Phagocytosis of HAp/ PLLA and bone was
noticed on both implants' preparations. Blood vessels were also noticed,
confirming the process of angiogenesis around the implants' particles.
The holes around particles of biocomposites and bone fragments represented
the signs of their resorption. The presence of multinuclear cells between
implants' particles was observed and it was more prominent in HP3 implants.
Osteogenesis is more intense in HP3 and ectopic hematopoesis is present.
Our results show that designed HAp/PLLA biocomposites have good biocompatibility,
their combination with bone fragments of a vital bone enables osteogenesis
and hematopoesis and these processes are more prominent if PLLA biocomposite
with lower molecular mass was used.
Key words: Subcutaneous implantation, hidroxyapatite, polylactide,
biocomposite
PROMENE BIOKOMPOZITA HAp/PLLA
I REAKCIJA TKIVA
POSLE SUBKUTANE IMPLANTACIJE
Kratak sadržaj: Eksperimentalna i klinička istraživanja su pokazala
da se granule i prah HAp mogu uspešno primeniti za rekonstrukciju koštanih
defekata. Kompozitni biomaterijal HAp/PLLA objedinjuje dobre osobine koje
poseduje svaki od ovih biomaterijala. Razlike u poroznosti, mikrostrukturi,
kompresionoj čvrstoći kao i bioresorbilnost HAp/PLLA postižu se korišćenjem
PLLA različitih molskih masa. Cilj rada je bio da se svetlosnom mikroskopijom
analiziraju odgovor tkiva i promene implantata napravljenih od kombinacije
singenih koštanih fragmenata i biokompozita HAp/PLLA sa PLLA molekulske
mase od 430 000 (HP2) i 50 000 (HP3). Miševi su bili podeljeni u 4 eksperimentalne
grupe od po 8 životinja. U dve grupe je urađena implantacija, jedna grupa
miševa su bili lažno operisani, a jedna grupa je služila kao opšta kontrola.
Posle 3 meseca od subkutane implantacije rađena je patohistološka analiza
implantata. Na preparatima oba tipa implantata se vidi fagocitoza HAp/PLLA
i kosti. Takođe su vidljivi krvni sudovi koji svedoče o procesu angiogeneze
u okolini partikula implantata. Prazna polja oko partikula biokompozita
i koštanih fragmenata predstavljaju znake njihove resorpcije. Vidljivo
je prisustvo multinuklearnih ćelija između partikula implantata, a to je
izraženije u HP3 implantatima. U HP3 je intenzivnija osteogeneza
i prisutna je ektopična hematopoeza. Naši rezultati pokazuju da dizajnirani
biokompoziti HAp/PLLA imaju dobru biokompatibilnost, da je u njihovoj kombinaciji
sa koštanim fragmentima žive kosti moguća osteogeneza i hematopoeza i da
su ovi procesi izraženiji ako je u biokompozitu PLLA manje molekulske mase.
Ključne reči: Subkutana implantacija, hidroksiapatit, polilaktid,
biokompozit
