14 research outputs found
Resorbable scaffolds modified with collagen type I or hydroxyapatite : in vivo studies on rabbits
Surface-modified poly(l-lactide-co-glycolide) scaffolds for the treatment of osteochondral critical size defects : in vivo studies on rabbits
Poly(l-lactide-co-glycolide) (PLGA) porous scaffolds were modified with collagen type I
(PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check
their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using
solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the
range of 250–320 µm. The physico-chemical properties of the scaffolds were evaluated using scanning
electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD),
X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), sessile drop,
and compression tests. Three types of the scaffolds (unmodified PLGA, PLGA/coll, and PLGA/HAp)
were implanted into the defects created in New Zealand rabbit femoral trochlears; empty defect acted
as control. Samples were extracted after 1, 4, 12, and 26 weeks from the implantation, evaluated
using micro-computed tomography (µCT), and stained by Masson–Goldner and hematoxylin-eosin.
The results showed that the proposed method is suitable for fabrication of highly porous PLGA
scaffolds. Effective deposition of both coll and HAp was confirmed on all surfaces of the pores
through the entire scaffold volume. In the in vivo model, PLGA and PLGA/HAp scaffolds enhanced
tissue ingrowth as shown by histological and morphometric analyses. Bone formation was the
highest for PLGA/HAp scaffolds as evidenced by µCT. Neo-tissue formation in the defect site was
well correlated with degradation kinetics of the scaffold material. Interestingly, around PLGA/coll
extensive inflammation and inhibited tissue healing were detected, presumably due to immunological
response of the host towards collagen of bovine origin. To summarize, PLGA scaffolds modified with
HAp are the most promising materials for bone tissue regeneration