Effect of polydeoxyribonucleotide and polynucleotide on rotator cuff healing and fatty infiltration in a diabetic rat model

Fig. 1. Flow diagram. PDRN: polydeoxyribonucleotide, PN: polynucleotide, DM: diabetes mellitus, Rt: right.

Fig. 2. Repair of chronic infraspinatus tear. (A) Chronic tear of infraspinatus, (B) Repaired infraspinatus.

Fig. 3. The material testing machine. (A) Instron 5543 connected with a pneumatic grip and a rat muscle fixation device (KR Design Registration 30-0854878), (B) Application of tensile load to the infraspinatus of the rat.

Fig. 4. Histologic grading. (A) * H&E stain at the musculotendinous region used a four-scale system (grades 0, 1, 2, and 3), where a grade 0 = no fat deposits and 3 = fat droplets found in most fibers. (B-C) § H&E and Masson’s Trichrome stains at the tendon-to-bone junction, where a portion of < 25% of proportion: grade 0 (g0: absent or minimal); 25 ~ 50%: grade 1 (g1: mild degree); 50 ~ 75%: grade 2 (g2: moderate degree); > 75%: grade 3 (g3: severe (marked) degree). G1: Group 1, saline + repair; G2: Group 2, saline + repair; G3: Group 3, PDRN + repair; G4: Group 4, PN + repair. G1: normal, G2-4: DM, sham 1 and 2: left shoulder of the G1 and G2 groups.

Fig. 5. Immunohistochemistry (S100, CD 68 and CD 168) and cross-sectional area at the musculotendinous region. (A) The number of adipocytes on S100 staining, (B) The number of macrophages on CD 68 staining, (C) The number of macrophages on CD 168 staining, (D) The cross-sectional area of the muscle fiber. G1: saline + repair; G2: Saline + Repair; G3: PDRN + Repair; G4: PN + Repair. G1: normal, G2-4: DM, sham 1 or 2: left shoulder of G1 or G2, CSA: cross-sectional area of the muscle fiber. The error bars show the standard deviations. Asterisks show a statistically significant difference between the two groups (P < .05).

Fig. 6. The histological and immunohistochemical findings. (A) Grading for adipocytes on H&E staining of the M-T region (x200). Black arrows are adipocytes. (B) S100 stained cells in the M-T region (x400). Black arrows are S100-stained adipose cells. The G3 and G4 groups showed fewer adipocytes than the G2 groups. (C) CD 68-stained cells in the M-T region (x400). Black arrows are CD 68-stained cells. The G3 and G4 groups showed fewer CD68-stained cells than the G2 group. The G3 group showed the lowest number of CD 68-stained cells. (D) CD 168-stained cells in the M-T region (x400). Black arrows are CD168-stained cells. The G3 and G4 groups showed more CD168-stained cells than the G1 and G2 groups. (E) Collagen fiber continuity and parallel orientation on Masson’s trichrome stain (x100) of T-B junction. Black arrows are T-B junctions. The G3 and G4 groups showed more continuous and parallelly oriented collagen fibers than the G2 group. The G1 and G2 groups showed no definite T-B junctions. (F) CSA on H&E staining of the M-T region (x400). The G3 group showed the largest CSA, and the G2 group showed the smallest CSA. 1: sham 1; 2: sham 2; 3: G1; 4: G2; 5: G3; 6: G4. Sham 1 and 2: left…

Fig. 7. Mean plasma levels of growth factors. (A) VEGF (vascular endothelial growth factor), (B) FGF (fibroblast growth factor), (C) IGF (insulin-like growth factor), 2nd OP: the repair operation, 2nd injection: additional injection 2 weeks after the repair operation, sacrifice: sacrifice 4 weeks after the repair operation, G1: Group 1, saline + repair; G2: Group 2, saline + repair; G3: Group 3, PDRN + repair; G4: Group 4, PN + repair. The error bars show the standard deviations. Asterisks show a statistically significant difference between the two groups (P < .05).