ABSTRACT:
The regeneration of damaged organs requires that
engineered tissues mature when implanted at sites of injury or disease.
We have used new analytic techniques to determine the extent of tissue
regeneration after treatment of knee injury patients with a novel
cartilage tissue engineering therapy and the effect of pre-existing
osteoarthritis on the regeneration process. We treated 23 patients,
with a mean age of 35.6 years, presenting with knee articular cartilage
defects 1.5 cm2 to 11.25 cm2 (mean, 5.0 cm2) in area. Nine of the
patients had X-ray evidence of osteoarthritis. Chondrocytes were
isolated from healthy cartilage removed at arthroscopy. The cells were
cultured for 14 days, seeded onto esterified hyaluronic acid scaffolds
(Hyalograft C), and grown for a further 14 days before implantation. A
second-look biopsy was taken from each patient after 6 to 30 months
(mean, 16 months). After standard histological analysis, uncut tissue
was further analyzed using a newly developed biochemical protocol
involving digestion with trypsin and specific, quantitative assays for
type II collagen, type I collagen, and proteoglycan, as well as mature
and immature collagen crosslinks. Cartilage regeneration was observed
as early as 11 months after implantation and in 10 out of 23 patients.
Tissue regeneration was found even when implants were placed in joints
that had already progressed to osteoarthrosis. Cartilage injuries can
be effectively repaired using tissue engineering, and osteoarthritis
does not inhibit the regeneration process (1 Hollander et. al)
PMID: 16889509 [PubMed - indexed for MEDLINE]