Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neocartilage was engineered by culturing bovine chondrocytes on poly(glycolic acid) (PGA) fibrous nonwoven scaffolds. The biomechanical properties and morphologies of the PGA-chondrocyte constructs were studied over 12 weeks of in vitro culture. PGA scaffolds without cells lost their mechanical strength and structural integrity between week 2 and week 3 in culture. The thickness of the PGA-chondrocyte constructs decreased by 35% during the first 3 weeks, but the thickness increased from week 3 to week 9 to a thickness 42% higher than that of the starting scaffolds, which was then maintained. Safranin O staining of PGA-chondrocyte constructs revealed increasing proteoglycan formation over time. The compressive modules of PGA-chondrocyte constructs increased with in vitro culture time, and reached the same order of magnitude as that of normal bovine cartilage at week 9. The aggregate modulus of the PGA-chondrocyte constructs decreased by 57% over the first 2 weeks but then increased, reaching the same order of magnitude as normal bovine cartilage at week 12. The apparent permeability of the PGA-chondrocyte constructs, which was initially four orders of magnitude above that of normal cartilage, decreased between weeks 1 and 3 and thereafter remained the same order of magnitude as that measured for normal cartilage.
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PMID:Development of biomechanical properties and morphogenesis of in vitro tissue engineered cartilage. 860 Jan 49

The use of biodegradable scaffolds for articular cartilage repair has been investigated by numerous researchers. The objective of this screening study was to examine how the mechanical and physical properties of four multiphase implants can affect the cartilage healing response. Multiphase implant prototypes were prepared using poly(D,L)lactide-co-glycolide as the base material. PGA fibers (FR), 45S5 Bioglass (BG) and medical grade calcium sulfate (MGCS) were used as additives to vary stiffness and chemical properties. Osteochondral defects (3 mm dia. and 4 mm in depth) were created bilaterally in the medial femoral condyle (high-weight bearing) and the distal medial portion of the patellar groove (low-weight bearing) of 16 Spanish goats. Half of the implants were loaded with autologous costochondral chondrocytes. Defect sites (total n = 64, 4 sites/treatment) were randomly treated and allowed to heal for 16 weeks, fully weight bearing. At euthanasia, gross evaluations and biomechanical testing were conducted. Histological sections of the defect sites were stained with H and E, Safranin O/Fast Green or processed to analyze collagen architecture. Sections were semi-quantitatively scored for repair tissue structure. Qualitative evaluations showed that all groups had a high percentage of hyaline cartilage and good bony restoration, with new tissue integrating well with the native cartilage. Gross and histology scoring indicated a significantly higher score for defect healing in the condyle than in the patellar groove, but no difference in healing for implant types or addition/omission of cells was found. This investigation demonstrates that focal, osteochondral defects in caprine distal femurs treated with various implant constructs were repaired with hyaline-like cartilage and good underlying bone. The multiphase implants show potential for treatment of osteochondral defects and long-term studies need to be undertaken to confirm the longevity of the regenerated tissue.
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PMID:Evaluation of multiphase implants for repair of focal osteochondral defects in goats. 1107 6