Search

Objectives: This study aimed to prepare functional composite electrospinning fibrous membranes with the functions of antifibrosis and bacteriostasis, as well as to explore its repair effect on rat jaw defect., Methods: Poly-(lactic acid-co-glycolic acid) fibrous membrane loaded with cyclic-arginine-glycine-aspartic acid sequence, ornidazole, and nanohydroxyapatite (n-HA) was prepared by electrospinning as the functional layer (GBRL) for adhering onto defective bone. A barrier layer with the function of supporting and isolating different functional layers was prepared by tape-casting method. Poly(p-dioxanone-co-l-phenylalanine) fiber membrane with the function of inhibiting fibrosis was prepared by electrospinning technology as the antifibrosis layer (AFL). The morphology of the composite membrane was characterized by scanning electron microscopy. The effects of different functional layers on the proliferation of mouse osteoblast precursor cells (MC3T3-E1) and mouse fibroblasts (L929) were studied by cell-proliferation test (CCK-8 method). The inhibitory effect of composite membrane on the proliferation of Porphyromonas gingivalis was studied by bacteriostatic circle test. A rat mandibular-bone defect model was established to study the repair effect of composite fiber membrane on bone-defect tissue. This repair effect was compared with that of collagen oral-repair membrane commonly used in clinics., Results: The GBRL layer could support the proliferation of MC3T3-E1 cells, and the AFL layer could inhibit the proliferation of L929 cells. Composite membranes loaded with ornidazole could inhibit the proliferation of Porphyromonas gingivalis . Various composite membranes can induce the reconstruction of rat jaw defects, among which the composite membranes loaded with ornidazole and n-HA had the best repair effect, which was better than that of collagen oral-repair membrane., Conclusions: The electrospun membrane loaded with ornidazole and n-HA as the composite fiber membrane of GBRL layer had excellent antibacterial and bone-tissue-regeneration activity. The effect was better than that of the commonly used collagen oral-repair membrane. Therefore, this material has great potential to induce bone regeneration for defects caused by periodontal diseases.

We investigated the luminescence characters of the ethanol solutions containing metallic ions and heterocyclic selenium compounds with different molecular structures in this paper. Heterocyclic selenium compounds included piazselenole (PS), 4,5-benzopiazselenole (BP), 5-methyl-piazselenole (MP), and 4,4'-dipiazselenole (DP). The results were as follows: (1) When the conjugative effect of piazselenoles increased, the emission spectrum shifted to lower frequencies; (2) Sn(IV) made the DP emission wavelength shorten. Sn(IV) reduced the fluorescence of MP, but caused fluorescence enhancement for BP and DP. The fluorescence of PS couldn't be detected at normal temperature, but strong fluorescence of PS was determined when the ratio of nSn(IV)/n(PS) was 0.5; (3) Sn(IV), Cr(III), Cd(II), Cu(II) and Sb(III) caused fluorescence enhancement for BP. The fluorescence of BP was reduced when increasing the concentration of Fe(III) and Fe(II). Zn(II) had little effect on the fluorescence of BP.

It has been proved by medicinal practice that the extraction from chicken bile has excellent antiphlogistic and anti-tumour effects. Chicken bile and the biles of various animals were dried and after IR spectral analyses, different IR spectra can be obtained with the resulting powders. In comparison with IR spectra, the IR spectrum from chicken bile is significantly different with that of other animals; whereas there are very good consistency among the chicken biles from different origin samples. The analyses of chicken bile show the chemical composition of chicken bile is different from that of other animals and the biles of different chicken have essentially same chemical composition.

This study was intended to address the mechanism of the degradation for the bioabsorbable materials poly(epsilon-caprolactone) (PCL) in vitro and in vivo by measurement of changes in intrinsic viscosity, number average molecular weight and crystalliniy. The test demonstrated that the degradation in rabbit was quicker than that in vitro. This illustrates that the mechanism of bioerosion in vivo is as important as the nonenzymatic random hydrolytic cleavage of ester linkages. Regardless of the initial Mn of the sample, a linear relationship between ln[eta] and time was observed until the Mn decreased to about 5000. Before this decrease of Mn, the main mechanism of degradation is hydrolytic cleavage of ester groups, with an accompanying enzymatic surface erosion, but after this decrease of Mn, the bioerosion with weight loss plays a role more significant than that the hydrolytic reaction plays in the degradation. The morphological characteristics of PCL materials after and before erosion were also compared by means of Scanning Electron Microscopy.