PRP Groups Research Articles

Platelet-rich plasma versus dexamethasone in inhibiting effect on osteogenic differentiation of human bone marrow mesenchymal stem cells

Objective To compare the effects of platelet-rieh plasma (PBP) and dexamethasone (DEX) on osteogenic differentiation of human bone marrow mesenchymal stromal cells (BMSCs). Methods BMSCs cultured in vitro were divided to 3 groups: fetal calf serum group (FCS group), PRP group (human BMSCs treated by PRP), and DEX group (human BMSCs treated by DEX) . Inverted phase contrast mi-croscopy, alkaline phosphate (ALP) staining, calcium staining and RT-PCR were used to determine gene expressions of ALP, osteocalcin (OC), collagen type Ⅰ (Coll-Ⅰ), osteonectin (ON), and core binding factor alpha 1 (Cbfα1) . The effects of PRP on osteogenic differentiation of human BMSCs were evaluated and compared with those of DEX. Results Most of the BMSCs treated by DEX were triangle or polygon in form while those treated by PRP were fusiform. At day 7, compared with FCS group, the number of ALP-positive cells in PRP group decreased (P < 0.05), but increased in DEX group (P < 0.05). At day 19, there was a significant difference in mineral deposition between PRP and FCS groups, with few calcium nodes in the PRP group (P < 0.05) . Compared with FCS group, treatment of Human BMSCs with DEX markedly increased mineral deposition, leading to much more calcium nodes (P < 0.05). DEX resulted in an earlier expression of OC at day 7 compared with FCS, and increased OC mRNA expressions at other culture time points. At the same time, DEX up-regulated ALP mRNA expression. Compared with FCS group, PRP decreased OC and ALP mRNA expressions. At different time points, the expressions of Cbfα1, ON, and Coll-Ⅰ mRNA showed no significant changes in the 3 groups. Conclusion PRP may have a direct effect on inhibiting osteogenic differentiation of human BMSCs, and can not be a substitute of DEX as an agent of osteogenic differentiation in vitro. Key words: Platelet-rich plasma; Bone mesenchymal stromal cells; Dexamethasone; Differentiation

Mesenchymal stem cells enhance bone regeneration in rat calvarial critical size defects more than platelete-rich plasma

The objective of this study was to compare culture-expanded bone marrow-derived mesenchymal stem cell and PRP loaded to natural bone mineral (Bio-Oss) and beta-TCP for rat calvarial bone repair. Twenty-two adult male Sprague-Dawley rats were randomly divided into 2 groups (n = 11). In the first group, 2 calvarial defects, 5 mm in diameter, were prepared in the parietal bone. The left defect was filled with Bio-Oss plus PRP while the right defect was filled with mesenchymal stem cell cultured on Bio-Oss. Kasios as a bone substitute was replaced in the second group. The animals were humanely killed 6 weeks postsurgery and the amount of the bone regeneration evaluated using histometric analysis. The bone fill length in the calvarial defect had statistically significant difference with other groups (P < .05). In both groups, mesenchymal stem cell revealed a higher percentage of bone formation in comparison with the PRP groups. New synthetic bone substitutes may offer a better condition for bone regeneration compared to the traditional bone substitute in combination with mesenchymal stem cells. They remained in the defect and contributed bone regeneration. The use of the mesenchymal stem cell in conjunction with bone substitutes can enhance bone regeneration more than PRP.

This Month in ANESTHESIOLOGY

This Month in ANESTHESIOLOGY

Safety and immunogenicity of Haemophilus influenzae type b polysaccharide and polysaccharide diphtheria toxoid conjugate vaccines in children 15 to 24 months of age

To evaluate the safety and immunogenicity of the Haemophilus influenzae type b polysaccharide vaccine, PRP, and a new polysaccharide-diphtheria toxoid conjugate vaccine, PRP-D, a collaborative study was carried out in six centers in five states. Subjects were 585 infants 15 to 24 months of age. They were randomly assigned to receive a single dose of PRP or PRP-D vaccine. There were no significant differences in the rate of adverse reactions between the two vaccine groups. Minor local reactions occurred in 10.3% of PRP and 12.5% of PRP-D recipients, and fever in 27.4% of PRP and 23.8% of PRP-D recipients. All reactions resolved within 48 hours. Serum samples were obtained just before vaccination and after 1 month. Prevaccination antibody levels were similar for the PRP (0.035 micrograms/mL) and PRP-D (0.027 micrograms/mL) groups, with no differences in levels by age, sex, race, vaccine lot, or study site. Both groups had significant rises in geometric mean levels, but this difference was significantly greater for PRP-D (2.166 micrograms/mL) than for PRP (0.154 micrograms/mL). In addition, the percentage of responders as determined by three definitions (twofold titer rise, greater than 0.15 micrograms/mL, and greater than 1.0 micrograms/mL) was also significantly greater for PRP-D than PRP. In contrast to a marked age-related immunogenicity to PRP (P less than 0.001), there was no significant variation in immune response to PRP-D by age. PRP-D conjugate vaccine appears to be as safe and significantly more immunogenic than PRP vaccine for children vaccinated at 15 to 24 months of age.