ABSTRACT
Objective To label human amniotic epithelial cells(hAECs) by using PEI-FeOnanoparticles. Methods The PEI-FeOnanoparticles were characterized by using transmission electron microscopy and dynamic light scattering. The primary cultured hAECs were labeled with the nanoparticles,and the labeling efficiency was evaluated by Prussian blue staining. The cell survival rate and viability were tested by using placenta blue staining and CCK-8 assay,respectively. Results The PEI-FeOnanoparticles were compact spheres with an average particle size of 13 nm,a hydrodynamic radius of 17.56 nm,and a zeta potential of+34.5 mV. The labeling efficiency of the nanoparticles on hAECs reached 91% when the concentrations were greater than 20 μg/ml. When the concentrations of nanoparticles were at 50 μg/ml(t=16.37,P<0.0001;t=10.39,P<0.0001) and 100 μg/ml(t=29.89,P<0.0001;t=16.86,P<0.0001),the cell survival rates and cell viabilities were significantly reduced versus controls. Conclusion The PEI-FeOnanoparticles can be used for labeling hAECs without obvious cytotoxicity at its working concentration.
ABSTRACT
Objective To observe the expression levels of matrix metalloproteinase-2 and 9 (MMP-2, MMP-9) in wound tissue and wound effusion in patients with chronic pressure ulcers treated with an alternating pres- sure relief mattress,and to correlate these observations with wound healing.Methods A total of 24 patients with chronic pressure ulcers were recruited and divided into two groups :one treated with an alternating pressure relief mat- tress and the other without,in addition to conventional treatment for pressure ulcers.The expression of MMP-2 and MMP-9 in the wound tissue and its exudate were amplified with a reverse transeriptase-polymerase chain reaction (RT-PCR) and analyzed using quantitative gelatin zymography.Wound healing was also observed and assessed using the pressure ulcer scale for healing (PUSH).Results The wounds were observed to heal well in both groups,as indicated by a significant decrease in the PUSH scores.Statistical analysis revealed a significant difference between the two groups with regard to the PUSH score on the 21st day after initiation of the study.With the healing of the pressure ulcers,the expression both MMP-2 and MMP-9 decreased.On the seventh and the 21st days,the expression of MMP-2 and MMP-9 in patients treated with an alternating pressure relief mattress was significantly less than in those without the mattress.Conclusion MMP-2 and MMP-9 can be biomarkers for the healing of pressure ulcers. An alternating pressure relief mattress is helpful for treating pressure ulcers.