ABSTRACT
In this study, dexamethasone (DXMS) and captopril (CAP) were co-loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles with a surface coating of a phospholipid bilayer, and then the core-shell nanoparticles were modified with polyethylene glycol and integrin α8 antibody to obtain immunoliposome-nanoparticle hybrids (DXMS/CAP@PLGA-ILs). The role of nanoparticles on the renal targeting, anti-inflammatory effects, and macrophage differentiation were investigated. The results showed that the particle size of the nanoparticles was 115.9 ± 2.89 nm, and the core-shell structure could be observed under an electron microscope. The drug loading capacity of DXMS and CAP was 5.72% ± 0.37% and 7.51% ± 0.07%, respectively. The results of in vitro experiments showed that DXMS/CAP@PLGA-ILs could reduce the secretion of specific cytokines and the mRNA expression of markers in M2-type macrophages, thus promoting the differentiation of M2-type macrophages in the direction of unpolarized macrophages. In vivo experiments in mice showed that DXMS/CAP@PLGA-ILs had a significant renal targeting effect, which could restore the renal index, serum creatinine, and urea nitrogen levels of mesangial proliferative glomerulonephritis in mice. Moreover, DXMS/CAP@PLGA-ILs could reduce both the secretion of inflammatory cytokines and the mRNA expression levels of M1 and M2 macrophage markers in the kidney. All the animal experiments were in accordance with the regulations of Animal Ethics Committee of Sichuan Agricultural University. In conclusion, renal-targeting DXMS/CAP@PLGA-ILs could effectively regulate the polarization of macrophages and had an "anti-inflammatory/anti-fibrosis" therapeutic effect, providing a new strategy and basis for the targeted therapy of glomerulonephritis.
ABSTRACT
<p><b>OBJECTIVE</b>To study large-scale expansion of SD (Sprague-Dawley) rat's osteoblasts in suspension culture in a rotating wall vessel bioreactor (RWVB).</p><p><b>METHODS</b>The bioreactor rotation speeds were adjusted in the range of 0 to 20 rpm, which could provide low shear on the microcarriers around 1 dyn/cm2. The cells were isolated via sequential digestions of neonatal (less than 3 days old) SD rat calvaria. After the primary culture and several passages, the cells were seeded onto the microcarriers and cultivated in T-flask, spinner flask and RWVB respectively. During the culture period, the cells were counted and observed under the inverted microscope for morphology every 12 h. After 7 days, the cells were evaluated with scanning electron microscope (SEM) for histological examination of the aggregates. Also, the hematoxylin-eosin (HE) staining and alkaline phosphatase (ALP) staining were performed. Moreover, von-Kossa staining and Alizarin Red S staining were carried out for mineralized nodule formation.</p><p><b>RESULTS</b>The results showed that in RWVB, the cells could be expanded by more than ten times and they presented better morphology and vitality and stronger ability to form bones.</p><p><b>CONCLUSIONS</b>The developed RWVB can provide the culture environment with a relatively low shear force and necessary three-dimensional (3D) interactions among cells and is suitable for osteopath expansion in vitro.</p>
Subject(s)
Animals , Rats , Bioreactors , Cell Culture Techniques , Cell Enlargement , Culture Media , Glucose , Metabolism , Hydrogen-Ion Concentration , Lactic Acid , Metabolism , Osmolar Concentration , Osteoblasts , Cell Biology , Metabolism , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To analyze the forces of rotational wall vessel (RWV) bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor.</p><p><b>METHODS</b>The motion of the microcarrier in the rotating wall vessel (RWV) bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation.</p><p><b>RESULTS</b>The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined.</p><p><b>CONCLUSION</b>The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.</p>