Articular cartilage repair using allogeneic perichondrocyteseeded biodegradable porous polylactic acid (PLA): A tissue‐engineering study

Abstract

Efforts to expand treatment options for articular cartilage repair have increasingly focused on the implantation of cell-polymer constructs. The purpose of this study is to determine the suitability of porous D,D-L,L-polylactic acid as a carrier for delivering repair cells obtained from rib perichondrium into full-thickness articular cartilage defects. In vitro characterization of perichondrocyte-polylactic acid composite grafts was combined with in vivo assessment of the early articular cartilage repair in a clinically relevant model. Using a fluorescent double-stain protocol to visualize live and dead cells in situ, primary cells cultured from perichondrium were found to be capable of attaching to and surviving within a porous D,D-L,L-polylactic acid matrix. These perichondrocyte-polylactic acid composite grafts were then implanted within osteochondral defects drilled into the left medial femoral condyles of 16 adult New Zealand white rabbits. Experimental animals were sacrificed 6 weeks after implantation and the repair tissue was evaluated grossly, histologically, and biochemically. Grossly, 96% (15/16) of the experimental animals demonstrated repairs consisting of a smooth, firm neocartilage which appeared similar in color and texture to the surrounding articular surface. Matrix staining for cartilaginous protein was seen surrounding chondrocyte-like cells in the cartilage regions of the repair. Cellular alignment was found to be related to scaffold architecture. These results suggest that scaffolds composed of porous D,D-L,L-polylactic acid support the growth of cartilaginous repair tissue and are compatible with both in vitro and in vivo survival of chondrogenic cells.

Emulsion Templating of Poly(lactic acid) Particles: Droplet Formation Behavior

“…Initially, D d ∝ Q d , and because f ∝ Q d /D d 3 , the relationship between f and Q d becomes f ∝ Q d −2 . In the dripping regime eq 2 can be applied and thus 17 , which means that the frequency of drop generation is virtually independent of the dispersed phase flow rate. In other words, any increase in drop formation time due to an increase in the diameter of the drops is fully compensated by the faster growth rate of droplets due to the increased rate of flow of the dispersed phase.…”

Material Properties of Fresh Cold-stored Allografts for Osteochondral Defects at 1 Year

“…Gross cartilage morphology was graded using a standard visual assessment score by two independent observers (AR, JZ) ( Fig. 2A-C) [2,3,15,58]. In addition, the same two observers (AR, JZ) made subjective assessments of the degree of host-donor interface.…”

Adeno-associated viral gene transfer of transforming growth factor-β1 to human mesenchymal stem cells improves cartilage repair

“…Similar to retroviral transfection, AAV transduction effects persist in hMSC through the critical 46 weeks when early osteochondral repair tissue forms. 12,16,35 Clinical rehabilitation following cartilage repair procedures also focus on supporting the repair process during this time frame. Numerous studies using retroviral gene transfer of growth factors such as rhOP-1, rhBMP-2, rhBMP-7 and other cartilage-friendly growth factors have been shown to improve osteochondral repair.…”

“…[9][10][11] Owing to the limited repair potential of mature differentiated chondrocytes, there has been a strong interest in using mesenchymal stem cells for cartilage tissue engineering. 1,[12][13][14] Bone marrow cells are routinely accessed clinically for cartilage repair and form the basis for the repair of osteochondral injuries. [15][16][17] The chondrogenic potential of human mesenchymal stem cells (hMSC) is well described.…”