1. Volume 32, Issue 4, Pages 381-386 (April 2003)
Local bone formation by injection of recombinant human bone morphogenetic protein-2 contained in polymer carriers 
N Saito, T Okada, H Horiuchi, H Ota, J Takahashi, N Murakami, M Nawata, S Kojima, K Nozaki, K Takaoka 
Bone 
Volume 32, Issue 4, Pages (April 2003)
DOI: /S (03)

2. Fig. 1
Structural formula of poly-d,l-lactic acid–polyethylene glycol block copolymer (PLA–PEG). m,n,o, number of units.
Bone  , DOI: ( /S (03) )

3. Fig. 2
Liquid–semisolid transition curve. Conditions of liquid or semisolid were determined by surface conditions of polymers when tilted at a 45° angle. The liquid–semisolid transition point (transitional temperature) of five polymers was defined as the lowest temperature at which the polymer showed liquid condition (horizontal surface), and plotted against total molecular weights of polymers. The transitional temperature of each polymer increased as a function of the molecular weight of the polymer.
Bone  , DOI: ( /S (03) )

4. Fig. 3
New ectopic bone formation 3 weeks after implantation of five types of PLA–PEG implants with 10 μg of rhBMP-2 into the back muscles of ddy mice. (A) Soft X-ray photographs show the radiopaque area with a trabecular pattern. The ossicles in the P6400 group were the largest. (B) Histological results for the P900, P2100, P3200 and P6400 groups were the same. Light microscopy of the P6400 group shows new bone formation with hematopoietic marrow (M) and bony trabeculae (T) without polymer remnants. There was no evidence of inflammation of foreign-body reactions in the host tissues (H) adjacent to the new bone. (C) Histology of 9500 showed some remnants of the polymer (arrows) in the center of the ossicle. Hematoxylin and eosin stain. Scale bar, 100 μm.
Bone  , DOI: ( /S (03) )

5. Fig. 4
Single energy X-ray absorptiometry analysis of the ectopic new bone induced by five types of polymers with 10 μg of rhBMP-2 and by the collagen with the same dose of rhBMP-2 3 weeks after implantation. (A and B) In P900, P2100, P3200, and P6400 polymer groups, both the BMC and BMD values of the ectopic new bone correlated with the increase in total molecular weight of the polymers, but both values were significantly higher for the P6400 group than for the P9500. Both values were significantly higher for the P6400 group than for the collagen. (A) BMC; n = 5 per group. a, P < 0.05 versus P900; b, P < 0.05 versus P900, P2100, P3200, P9500, and collagen. (B) BMD; n = 5 per group. a, P < 0.05 versus P900; b, P < 0.05 versus P900 and P2100; c, P < 0.05 versus P900, P2100, P3200, P9500, and collagen.
Bone  , DOI: ( /S (03) )

6. Fig. 5
New bone formation by injection. (A–C) New orthotopic bone was formed by injection of PLA–PEG/BMP composites (25 μg of P6400 with 10 μg of rhBMP-2) into the muscle pouch on the abraded surface of the murine femur (3 weeks after injection). (A) Soft X-ray photograph. Arrows indicate new bone. (B) Light micrograph of the host–new bone interfaces. New bone with bony trabeculae (BT) and hematopoietic marrow (HM) was attached to the surface of the host bone (HB). Arrowheads indicate host–new bone interfaces. (C) Light micrograph of interface between surrounding soft tissues (ST) and new bone (NB). There was no evidence of inflammation, foreign-body reactions, nor granulation formation in surrounding muscle tissues. Arrowheads indicate surrounding tissue–new bone interfaces. Hematoxylin and eosin stain. Scale bar, 100 μm.
Bone  , DOI: ( /S (03) )

7. Fig. 6
Injectable rhBMP-2 delivery system. When heated at 60°C, PLA–PEG/rhBMP-2 composites can be injected percutaneously with a syringe, thus avoiding the need for surgical implantation. Subsequently, they become firm when they cool to body temperature, resulting in semisolid polymeric implants in the body.
Bone  , DOI: ( /S (03) )