Effect of blood on the morphological, biochemical and biomechanical properties of engineered cartilage

Abstract

The use of autologous chondrocytes seeded onto a biological scaffold represents a current valid tool for cartilage repair. However, the effect of the contact of blood to the engineered construct is unknown. The aim of this work was to investigate in vitro the effect of blood on the morphological, biochemical and biomechanical properties of engineered cartilage. Articular chondrocytes were enzymatically isolated from swine joints, expanded in monolayer culture and seeded onto collagen membranes for 2 weeks. Then, the seeded membranes were placed for 3 days in contact with peripheral blood, which was obtained from animals of the same species and diluted with a standard medium. As controls, some samples were left in the standard medium. After the 3 days' contact, some samples were retrieved for analysis; others were returned to standard culture conditions for 21 additional days, in order to investigate the "long-term effect" of the blood contact. Upon retrieval, all seeded samples showed increasing sizes and weights over time. However, the samples exposed to blood presented lower values with respect to the controls. Biochemical evaluation demonstrated a reduction in the mitochondrial activity due to blood contact at the early culture time (3 days post blood contact), followed by a partial recovery at the longer culture time (21 days post blood contact). Histological evaluation demonstrated evident cartilage-like matrix production for both groups. Biomechanical data showed a reduction of the values, followed by stabilization, regardless of the presence of blood. Based on the data obtained in this study, we can conclude that blood contact affects the chondrocyte activity and determines a delay in the dimensional growth of the engineered cartilage; however, at the experimental times utilized in this study, this delay did not affect the histological pattern and the biomechanical properties of the construct.

Response of Human Engineered Cartilage Based on Articular or Nasal Chondrocytes to Interleukin-1β and Low Oxygen

“…23,24 Similar results were also reported using porcine chondrocyte-based engineered cartilage exposed to whole blood, in order to duplicate the postsurgical intraarticular bleeding, which is likely to be the major source of IL-1b after implantation. 25,26 Although interesting, those results cannot be directly compared to those of the current study because of the use of tissues harvested from very young animals, as opposed to human chondrocytes from adult individuals.…”

Osteochondral Repair by a Novel Interconnecting Collagen–Hydroxyapatite Substitute: A Large-Animal Study

“…However, it is not known if the transplanted chondrocytes survived in this orthotopic model as the cells were not labelled. Considering the substantial changes that occur from the in vitro to in vivo environment, it is probable that other factors may have, in fact, influenced the survival and the activity of the transplanted cells, like the limited diffusion of nutrients or, more likely, the inflammatory stimuli generated within the joint cavity, which may have damaged the transplanted cells [47][48][49]. In this hypothetical situation, tissue regeneration would depend on activity of cells recruited into the scaffold from the lesion site.…”

Cell-Seeded Collagen Matrix–Supported Autologous Chondrocyte Transplantation (ACT-CS)

“…A negative effect of blood on biochemical and morphological properties of regenerated cartilage has been demonstrated. 29 , 30 In addition, direct contact of the seeded cellular layer of the membrane, unencumbered by a bone marrow–derived cellular infiltrate, may allow for better basal integration.…”