RESUMO
As a result of their close similarities to the inorganic mineral components of human bone, hydroxyapatite nanoparticles (n-HAp) are widely used in biomedical applications and for the elaboration of biocompatible scaffold drug delivery systems for bone tissue engineering. In this context, a new efficient and economic procedure was used for the consolidation of n-HAp in the presence of various Nigella sativa (NS) fractions at a near-room temperature. The research conducted in the present study focuses on the physicochemical properties of loaded n-HAp 3D scaffolds by NS fractions and the in vitro antibacterial activity against Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27853), and Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 700603) bacteria. In order to better understand the effect of the inserted fractions on the HAp molecular structure, the elaborated samples were subject to Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopic analyses. In addition, the morphological investigation by scanning electron microscope (SEM) of the loaded n-HAp 3D scaffolds demonstrated the presence of a porous structure, which is generally required in stimulating bone regeneration. Furthermore, the fabricated 3D composites exhibited significant antibacterial activity against all tested bacteria. Indeed, MIC values ranging from 5 mg/mL to 20 mg/mL were found for the HAp-Ethanol fraction (HAp-Et) and HAp-Hexane fraction (HAp-Hex), while the HAp-Aqueous fraction (HAp-Aq) and HAp-Methanol fraction (HAp-Me) showed values between 20 mg/mL and 30 mg/mL on the different strains. These results suggest that the HAp-NS scaffolds were effective as a drug delivery system and have very promising applications in bone tissue engineering.
RESUMO
This study investigated the effects of high amylose starch (HAS) consumption on gut functions in male Sprague-Dawley rats. Experimental animals were fed an diet containing HAS for 4 weeks (0, 125, 250, 500 g/kg diet). Stool weights, transit time, the pH of cecum, Bifidobacterium growth, short chain fatty acid production, and prostaglandin E2 production in colon mucus were measured. HAS intake did not affect body weight gain or food efficiency ratio during experimental period. There were no significant differences in kidney weight, epididymal fat pad weights or spleen weights, but the weights of the liver and thymus were significantly lower in the HAS100 group. The length of the large intestine, the weights of the cecum wall and cecum contents, and stool weights significantly increased through HAS intake. But transit time was not affected by the experimental diet. Although Bifidobacterium growth in the cecum increased through the HAS intake dose dependently, there were significant differences in the HAS50 and HAS100 groups. HAS intake increased the production of short chain fatty acid in the cecum contents. In particular, acetate and butyrate concentrations grew significantly. And the production of prostaglandin E2 in the colon mucus significantly decreased through HAS intake. These results demonstrate that high amylose starch intake significantly improves gut function.
