Identifying a suitable polymeric biomaterial for myocardial patch repair following myocardial infarction, cerebral infarction, and cartilage injury is essential. This study aimed to investigate the effect of the novel polymer material, poly3-hydroxybutyrate-co-3-hydroxyhexanoate, on the adhesion, proliferation, and differentiation of mouse-induced pluripotent stem cells in vitro. Mouse-induced pluripotent stem cells were isolated, expanded, and cultured on either two-dimensional or three-dimensional poly3-hydroxybutyrate-co-3-hydroxyhexanoate films (membranes were perforated to imitate three-dimensional space). Following attachment onto the films, mouse-induced pluripotent stem cell morphology was visualized using scanning electron microscopy. Cell vitality was detected using the Cell Counting Kit-8 assay and cell proliferation was observed using fluorescent 4',6-diamidino-2-phenylindole (DAPI) staining. Mouse-induced pluripotent stem cells were induced into cardiomyocytes by differentiation medium containing vitamin C. A control group in the absence of an inducer was included. Mouse-induced pluripotent stem cell survival and differentiation were observed using immunofluorescence and flow cytometry, respectively. Mouse-induced pluripotent stem cells growth, proliferation, and differentiation were observed on both two-dimensional and three-dimensional poly3-hydroxybutyrate-co-3-hydroxyhexanoate films. Vitamin C markedly improved the efficiency of mouse-induced pluripotent stem cells differentiation into cardiomyocytes on poly3-hydroxybutyrate-co-3-hydroxyhexanoate films. Three-dimensional culture was better at promoting mouse-induced pluripotent stem cell proliferation and differentiation compared with two-dimensional culture.

The purpose of this study was to investigate the most suitable polymer material for supporting stem cell growth as a myocardial patch. After cell isolation and expansion of mouse bone marrow mesenchymal stem cells (BMSC), the cells were induced to differentiate into cardiomyocytes with 5-azacytidine to determine their differentiation potential. BMSCs were also seeded onto three types of polymer material film, including polyurethane (PU), 3-hydroxybutyrate-co-4-hydroxybutyrate [P(3HB-co-4HB)], and polypropylene carbonate (PPC). The results revealed that cell numbers were more abundant on both the PU and P(3HB-co-4HB) material surfaces. Conversely, the surface of PPC was smooth with only cell lysate debris observed. The average cell counts were as follows: 143.78 ± 38.38 (PU group), 159.50 ± 33.07 [P(3HB-co-4HB) group], and 1.40 ± 0.70 (PPC group). There was no statistically significant difference in cell numbers between the PU and P(3HB-co-4HB) groups. A statistically significant difference was identified between the PPC group and both the PU (P1) and P(3HB-co-4HB) groups (P2). Polymer biomaterial patches composed of PU and P(3HB-co-4HB) permit good stem cell growth. P(3HB-co-4HB) has the potential for development as a clinical alternative to current treatment methods for the regeneration of cardiomyocytes in patients with myocardial infarction.

Comparing patients receiving a loading dose of statins with those receiving a regular dose after CABG, the medium- and long-term efficacy of a loading dose showed significant reduction in LDL-C, lower occurrence of adverse cardiac events, and reduction in graft restenosis. Although the incidence of drug-related side effects was slightly higher in the loading-dose group, in the majority of patients they were not serious. Overall, a loading dose of statins is superior to regular dosing of statins after CABG.