This research was carried out to investigate the effect of basic fibrous growth factor (bFGF) controlled release hydrogel nanoparticles on the proliferation and differentiation of mesenchymal stem cells. The dex-GMA-bFGF-NPs were prepared by an improved emulsion polymerization method; their morphology, size and encapsulated ratio were assessed by routine procedure. Dynamic dialysis method was used to determine the release characteristics of dex-GMA-bFGF-NPs in vitro. The secondary culture MSCs were divided into four groups according the different ingredients being added into the DMEM culture medium: free bFGF group (A), blank dex-GMA nanoparticles group (B), dex-GMA-bFGF nanoparticles group (C), nothing group (D). The proliferation of cultured MSCs was measured by using cell counting method, MTT method and flow cytometry. ALP kit was used to evaluate the ALP activity of the MSCs to show the differentiation of the cells by adding the dex-GMA-bFGF-NPs to the DMEM culture medium (C group) or bFGF only (A group). B group and D group were taken as the controls. The results were analyzed by statistical analysis software (SPSS11.0). All results showed that the shape of dex-GMA-bFGF-NPs was spherical. The encapsulated ratio was 88% and more than 85% of the encapsulated bFGF could be released during 14 days. The in vitro cellular study showed the control release of bFGF from nanoparticles could promote the proliferation of MSCs. After 12 days, the cell number in groups A, B and C was (21.97 +/- 0.25) x 10(4) cells/ml, (12.43 +/- 0.13) x 10(4) cells/ml, (27.45 +/- 0.78) x 10(4) cells/ml and (12.03 +/- 0.43) x 10(4) cells/ml, with the difference being statistically significant among them (P < 0.05). The flow cytometry revealed that the G2/M+S percentage in group C was the highest at 4-8 days after plate culture(P < 0.05). During the first 3 days, the proliferation and differentiation of BMSCs between group A and group B were of no significance (P > 0.05), but were much faster than those of group C and D. After 7 days, dex-GMA-bFGF-NPs could enhance BMSCs proliferation and differentiation continually, but bFGF had no enhancement any more, the difference between group A and group B became more significant (P < 0.05). So we made the conclusions the bFGF loading dex-GMA hydrogel nanoparticles can release bFGF more than 21 days and can promote the proliferation and differentiation of the BMSCs through a long period of controlled release of bFGF. Dex-GMA-bFGF-NPs may be an ideal controlled release carrier for bioactive growth factors.
Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Culture Media ; Female ; Fibroblast Growth Factor 2 ; pharmacology ; Male ; Mesenchymal Stromal Cells ; cytology ; Nanoparticles ; Rats ; Rats, Sprague-Dawley

BACKGROUND: Although newly formed constructs of feasible pressure-preadjusted bone marrow mesenchymal stem cells (BMSCs) and platelet-rich fibrin (PRF) showed biomechanical flexibility and superior capacity for cartilage regeneration, it is still not very clear how BMSCs and seed cells feel mechanical stimuli and convert them into biological signals, and the difference in signal transduction underlying mechanical and chemical cues is also unclear. METHODS: To determine whether mechanical stimulation (hydrostatic pressure) and chemical cues (platelet-rich fibrin, PRF) activate canonical or noncanonical Wnt signaling in BMSCs, BMSCs cocultured with PRF were subjected to hydrostatic pressure loading, and the activation of the Wnt signaling molecules and expression of cartilage-associated proteins and genes were determined by western blotting and polymerase chain reaction (PCR). Inhibitors of canonical or noncanonical Wnt signaling, XVX-939 or L690,330, were adopted to investigate the role of Wnt signaling molecules in mechanically promoted chondrogenic differentiation of BMSCs. RESULTS: Hydrostatic pressure of 120 kPa activated both Wnt/b-catenin signaling and Wnt/Ca2+ signaling, with the the maximum promotion effect at 60 min. PRF exerted no synergistic effect on Wnt/b-catenin signaling activation. However, the growth factors released by PRF might reverse the promotion effects of pressure on Wnt/Ca2+ signaling. Real-time PCR and Western blotting results showed that pressure could activate the expression of Col-II, Sox9, and aggrecan in BMSCs cocultured with PRF. Blocking experiment found a positive role of Wnt/b-catenin signaling, and a negative role of Wnt/ Ca2+ signaling in chondrogenic differentiation of the BMSCs. Mutual inhibition exists between canonical and noncanonical Wnt signaling in BMSCs under pressure. CONCLUSION Wnt signaling participates in the pressure-promoted chondrogenesis of the BMSCs co-cultured with PRF, with canonical and noncanonical pathways playing distinct roles during the process.

Tracheostomy is a very common airway procedure in the treatment of critically ill neurological patients. At present, the traditional tracheal cannula fixation belt is easy to be contaminated, difficult to disinfect, and needs to be replaced regularly. It is prone to infection, skin injury, unplanned extubation and other adverse events, which cannot meet the clinical treatment effect and patient safety management. In order to overcome the above problems, the medical staff of the neurology intensive care unit of Henan Provincial People's Hospital designed a new type of tracheal cannula fixation belt to increase patient comfort and reduce complications, and obtained a National Utility Model Patent of China (ZL 2022 2 0855188.8). The main structure of the device includes a following shaped bending plate, a fastening belt, a locking pin, and a distance adjustment hole. The left and right sides of the shaped bending plate are equipped with fastening belts with breathable and anti-wear pads. The inner side of the left fastening belt is equipped with two sets of locking pins, and the outer surface of the right fastening belt and breathable and anti-wear pad is equipped with multiple sets of distance adjustment holes. Additionally, the back of the shaped bending plate is equipped with breathable buffer pads. The fastening belt can drive the following bending plate to stick tightly to the patient's neck. The operator installs the locking pin card into the distance adjustment hole according to the "one back" principle, and the fastening belts on both sides fix the device with the cooperation of the locking pin, greatly reducing the probability of excessive displacement of the tracheal tube during use, effectively improving the fixation effect of the device, strengthening the adaptability of the device to different personnel, and thus enhancing the practicality of the device. The new type of tracheal cannula fixation band is convenient, safe and efficient, which can increase patient comfort, reduce complications. It has certain clinical value and is suitable for clinical promotion.