We investigated the synergistic wound‐healing effects of D ‐glucosamine (GlcN) and collagen peptide ( : 10 000 Daltons soluble collagen (S‐Co)) on injured cartilage. A injured cartilage model in rabbit was surgically created. Under general anesthesia, three holes at articular cartilage of the medial trochlear (one hole) and trochlear sulcus (two holes) of a distal femur were created using a high‐speed orthopedic drill. After surgery, rabbits were orally administered with collagen peptide (S‐Co group), GlcN (G group), or both (CoG group) for 2 or 3 weeks. In addition, glycine (Gly group) was administered as a control for the S‐Co group in three rabbits. Control rabbits were provided with water ad lib. After 2 weeks, the holes were filled by fibroblasts and chondroblasts in the treatment group, whereas in the control group, the holes were not filled completely unlike for the treatment group. Even three weeks later, only a small change was seen in the control group. In the group receiving collagen and GlcN, the holes were completely filled by proliferating chondroblasts, remodeling of bony trabeculae was also observed. Image analysis of Safranin O‐ and Alcian blue‐stained specimens showed increased production of proteoglycans and glycosaminoglycans, respectively, not only in the injured site, but also in the normal cartilage in the treated groups. The most enhanced healing of injury and increase in Safranin O and Alcian blue positive materials was observed in the CoG group. As a result, simultaneous administration of collagen and GlcN gave a fairly enhanced healing on restoration of cartilage injuries.
Artificial cartilage injury at the stifle joint of a rabbit. a: proximal hole in trochlear sulcus; b: distal hole in trochlear sulcus; c: medial hole in medial trochlear ridge.
: 10 000 Daltons soluble collagen (S‐Co)) on injured cartilage. A injured cartilage model in rabbit was surgically created. Under general anesthesia, three holes at articular cartilage of the medial trochlear (one hole) and trochlear sulcus (two holes) of a distal femur were created using a high‐speed orthopedic drill. After surgery, rabbits were orally administered with collagen peptide (S‐Co group), GlcN (G group), or both (CoG group) for 2 or 3 weeks. In addition, glycine (Gly group) was administered as a control for the S‐Co group in three rabbits. Control rabbits were provided with water ad lib. After 2 weeks, the holes were filled by fibroblasts and chondroblasts in the treatment group, whereas in the control group, the holes were not filled completely unlike for the treatment group. Even three weeks later, only a small change was seen in the control group. In the group receiving collagen and GlcN, the holes were completely filled by proliferating chondroblasts, remodeling of bony trabeculae was also observed. Image analysis of Safranin O‐ and Alcian blue‐stained specimens showed increased production of proteoglycans and glycosaminoglycans, respectively, not only in the injured site, but also in the normal cartilage in the treated groups. The most enhanced healing of injury and increase in Safranin O and Alcian blue positive materials was observed in the CoG group. As a result, simultaneous administration of collagen and GlcN gave a fairly enhanced healing on restoration of cartilage injuries. 