Evaluation of Different Polymerisation Methods of Ocular Prosthesis Acrylic Resins on Subcutaneous Tissue Inflammatory Response in Rats.

Objectives: This study aimed to evaluate the influence of different polymerisation methods of acrylic resin for ocular prostheses on the subcutaneous tissue inflammatory response of rats. Methods: The study was conducted at the Basic Sciences Department, Araçatuba Dental School, São Paulo State University (UNESP), Brazil, from 2016 to 2018. The samples were prepared by water bath (WB), microwave energy (MW) or autopolymerisation (AP) (n = 20 samples per group). The inflammatory response (cell count and immunohistochemical analysis of interleukin [IL]-1ß, IL-6, tumour necrosis factor [TNF]-α, IL-17 and macrophage inflammatory protein-3α) was analysed by the implantation of a sample from each group in the subcutaneous tissue of 20 Wistar rats and evaluated after seven, 15, 30 and 60 days. The quantitative and qualitative data were analysed using analysis of variance and Tukey tests (P <0.05) and visual comparison, respectively. Results: There was a moderate inflammatory infiltrate for the MW and AP groups and a light infiltrate for the WB group after seven days. The inflammatory infiltrate and the immunolabeling of tested targets decreased gradually during the 60-day period. The AP group had the highest immunolabeling of TNF-α (seven days), IL-1ß and IL-17 (at 15 and 30 days) and IL-6 (at 30 and 60 days). The WB and MW groups showed greater immunolabeling at 15 and 30 days, while the MW group also had high results at 60 days. Conclusion: Polymerisation by microwave energy and by chemical activation resulted in a higher inflammatory response.

Chronic high glucose and insulin stimulate bone-marrow stromal cells adipogenic differentiation in young spontaneously hypertensive rats.

We evaluated whether genetic predisposition is sufficient to induce changes due to chronic high glucose (HG; 25 mmol/L) in the presence or absence of insulin (HGI; 10 µg/ml) on osteogenic differentiation and markers in bone-marrow mesenchymal stem cells (BMSCs) from young Wistar (WBMSCs) and spontaneous hypertensive rats (SBMSCs) without hypertension. HG suppressed osteogenic differentiation in both the strains, observed by mineralization inhibition and decreased levels of the osteogenic markers Runx2, osterix, osteopontin, and bone sialoprotein, compared to osteogenic medium (OM) cells. In WBMSCs, the effects of HG were associated with the down regulation of ERK1/2 and up regulation of p38 activities; however, HGI did not revert the effects of HG on MAPK activities. Moreover, HG did not affect MAPK signaling in SBMSCs compared to that in OM. HGI increased mineralization in WBMSCs compared to that in OM, but not in SBMSCs. High expression of peroxisome proliferator-activated receptor-gamma and glucose transporter type 4 in OM could be related with the predisposition to adipogenic differentiation noted in SBMSCs and was confirmed by emergence of adipocyte-like cells by HGI treatment. Downregulation of p38 and upregulation of JNK activities were observed in both BMSCs treated with HGI compared to those treated by HG. Ma (osmotic control) also suppressed osteogenic differentiation in both the strains. In conclusion, we demonstrated that SBMSCs from young spontaneous hypertensive rats, without hypertension but with genetic and epigenetic predisposition, exhibited decreased osteoblastic differentiation under HG and HGI did not revert the effects of HG in SBMSCs but increased adipogenic differentiation.