The purpose of this study is to synthesize nanometer calcium carbonate/poly(L-lactide) composites and evaluate its biocompatibility, and mechanical properties. The nanometer calcium carbonate/poly(L-lactide) composites was prepared by the method of solution mixing and cell culture. Its properties were analyzed using, mechanical tests, MTT assay, transmission electron microscope and scanning electron microscope. It was found that the new kind copolymer had good biocompatibility, nanometer calcium carbonate could enhance the strength of the pure poly (L-lactide) matrix. The nanometer calcium carbonate/poly (L-lactide) composites is a promising bioabsorbable material. It is worth further medical research.
Animals ; Biocompatible Materials ; Calcium Carbonate ; Cell Line ; Materials Testing ; Mice ; Nanostructures ; Polyesters ; Tensile Strength

Objective:To explore the relationships between sarcopenia and the clinical efficacy and prognosis of elderly patients with esophageal cancer who were treated by radical radiotherapy.Methods:The clinicopathological data of 134 elderly patients with esophageal cancer who received radical radiotherapy in Department of Radiotherapy, Affiliated Hospital of Yangzhou University from January 2013 to December 2018 were retrospectively analyzed. The muscle cross-sectional area at the level of the third lumbar vertebra was measured by using computed tomography (CT) images. These patients were divided into sarcopenia group ( n=56) and non-sarcopenia group ( n=78) according to the skeletal muscle index before radiotherapy. The efficacy and incidence of adverse reactions of the two groups were compared. Kaplan-Meier method was used to plot the survival curve, and Cox regression model was used to analyze prognostic factors. Results:There was a significant difference in the objective response rate between the sarcopenia and non-sarcopenia group at 1 month after radiotherapy [53.57% (30/56) vs. 71.79% (56/78) , χ2=4.71, P=0.030]. There was no significant difference in the disease control rate between the two groups [94.64% (53/56) vs. 91.03% (71/78) , χ2=0.21, P=0.651]. There was a significant difference in the total incidence of adverse reactions between the sarcopenia and non-sarcopenia group [67.86% (38/56) vs. 47.44% (37/78) , χ2=5.52, P=0.019]. By the end of the follow-up, the 1-, 3- and 5-year overall survival (OS) rates of 134 elderly patients with esophageal cancer who received radical radiotherapy were 91.0%, 73.1% and 55.2% respectively. The median OS of patients in the sarcopenia and non-sarcopenia group were 14 months and 26 months respectively, with a statistically significant difference ( χ2=9.84, P=0.002) . The median progression-free survival (PFS) of the two groups were 7 months and 18 months respectively, with a statistically significant difference ( χ2=9.91, P=0.002) . Univariate analysis showed that cT stage ( HR=2.45, 95% CI: 1.26-4.74, P=0.008) , cN stage ( HR=1.63, 95% CI: 1.06-2.50, P=0.027) , cTNM stage ( HR=2.04, 95% CI: 1.28-3.27, P=0.003) , body mass index (BMI) ( HR=2.23, 95% CI: 1.01-4.90, P=0.046) , pre-radiotherapy sarcopenia ( HR=2.45, 95% CI: 1.27-4.72, P=0.007) and chemotherapy ( HR=0.30, 95% CI: 0.11-0.83, P=0.020) were prognostic factors for OS; cT stage ( HR=2.27, 95% CI: 1.18-4.39, P=0.015) , cN stage ( HR=1.61, 95% CI: 1.04-2.47, P=0.030) , cTNM stage ( HR=1.90, 95% CI: 1.19-3.02, P=0.007) , BMI ( HR=1.98, 95% CI: 1.06-3.79, P=0.032) , pre-radiotherapy sarcopenia ( HR=1.79, 95% CI: 1.06-3.04, P=0.031) and adverse reactions ( HR=0.60, 95% CI: 0.38-0.97, P=0.037) were prognostic factors for PFS. Multivariate analysis showed that pre-radiotherapy sarcopenia ( HR=1.91, 95% CI: 1.22-3.00, P=0.005) was an independent prognostic factor for OS; BMI ( HR=1.80, 95% CI: 1.03-3.15, P=0.039) and pre-radiotherapy sarcopenia ( HR=2.00, 95% CI: 1.27-3.14, P=0.003) were independent prognostic factors for PFS. Conclusion:Sarcopenia before radiotherapy can be a useful predictor for prognosis in elderly patients with esophageal cancer who received radical radiotherapy, and patients with sarcopenia benefit less from treatment.