RESUMO
The periosteum, a vascularized tissue membrane, is essential in bone regeneration following fractures and bone loss due to some other reasons, yet there exist several research gaps concerning its regeneration. These gaps encompass reduced cellular proliferation and bioactivity, potential toxicity, heightened stiffness of scaffold materials, unfavorable porosity, expensive materials and procedures, and suboptimal survivability or inappropriate degradation rates of the implanted materials. This research used an interdisciplinary approach by forming a new material fabricated through electrospinning for the proposed application as a layer-by-layer tissue-engineered periosteum (TEP). TEP comprises poly(ε-caprolactone) (PCL), PCL/gelatin/magnesium-doped zinc oxide (vascular layer), and gelatin/bioactive glass/COD liver oil (osteoconductive layer). These materials were selected for their diverse properties, when integrated into the scaffold formation, successfully mimic the characteristics of native periosteum. Scanning electron microscopy (SEM) was employed to confirm the trilayer structure of the scaffold and determine the average fiber diameter. In-vitro degradation and swelling studies demonstrated a uniform degradation rate that matches the typical recovery time of periosteum. The scaffold exhibited excellent mechanical properties comparable to natural periosteum. Furthermore, the sustained release kinetics of COD liver oil were observed in the trilayer scaffold. Cell culture results indicated that the three-dimensional topography of the scaffold promoted cell growth, proliferation, and attachment, confirming its non-toxicity, biocompatibility, and bioactivity. This study suggests that the fabricated scaffold holds promise as a potential artificial periosteum for treating periostitis and bone fractures.
Assuntos
Gelatina , Alicerces Teciduais , Alicerces Teciduais/química , Gelatina/química , Periósteo , Biomimética , Óleo de Fígado de Bacalhau , Poliésteres/química , Engenharia Tecidual/métodosRESUMO
The present study aimed to evaluate the effect of chromium-loaded chitosan nanoparticles (Cr-CNPs) on the electrophysiological indices, gene expression of glucose transporters, and tissue glycogen in broilers. A total of 200 one-day-old broilers were randomly divided into five groups, with each having five replicates (n = 8). Group A was fed a corn-soybean meal diet, while the diets of groups B, C, D, and E were supplemented with 200, 400, 800, and 1200 µg/kg of Cr as Cr-CNPs, respectively. On day 35, the jejunum was collected for electrophysiological study, gene expression of glucose transporters, and tissues glycogen determination. The basal short-circuit current and tissue conductance before the addition of glucose was the same in all groups. Following the addition of glucose, the change in short-circuit current decreased (p < 0.05) in the jejunal tissues of birds supplemented with 400 and 1200 µg Cr-CNPs compared with the control group. Gene expression of SGLT-1 and GLUT-2 remained unaffected with supplementation. The serum glucose and liver glycogen concentration decreased (p < 0.05) linearly with supplementation, while no effect was observed on muscle glycogen. In conclusion, Cr-CNPs supplementation decreases the glucose absorption and liver glycogen content, without affecting the gene expression of glucose transporters.
RESUMO
Two new ballonigrin type lactone diterpenoids, named ballonigrin lactone A and B, have been isolated from the roots of Ballota limbata. Structure elucidation of the isolated compounds was based on spectroscopic {IR, 1H- and 3C-NMR, and 2D-NMR (HMQC, HMBC, COSY and NOESY} and EI-MS data.