Due to good biocompatibility and mechanical properties, magnesium (Mg) and its alloys are considered promising degradable materials for orthopedic applications. In this work, a Mg metal matrix composite (MMC) was fabricated using Mg-2.9Zn-0.7Zr alloy as the matrix and 1 wt% nano-hydroxyapatite (n-HA) particles as reinforcements. In vitro corrosion behavior and cytocompatibility of a Mg-Zn-Zr/n-HA composite and a Mg-Zn-Zr alloy were investigated. In contrast with the Mg-Zn-Zr alloy, the MMC has better properties. The average corrosion rate of MMC is 0.75 mm/yr after immersion in simulated body fluid (SBF) for 20 days, and the surface of MMC is covered with white Ca-P precipitates. The electrochemical test results show that the corrosion potential (E(corr)) of MMC increases to -1.615 V and its polarization resistance (R(p)) is 2.56 KOmega with the addition of n-HA particles. The co-cultivation of MMC with osteoblasts results in the adhesion and proliferation of cells on the surface of the composite. The maximum cell density is calculated to be (1.85+/-0.15) x 10(4)/l after 5 days of co-culture with osteoblasts. The average cell numbers for two groups after culturing for 3 and 5 days (P<0.05) are significantly different. All the results demonstrate that the Mg-Zn-Zr/n-HA composite can be potentially used as biodegradable bone fixation material.
The mechanisms involved in diabetic neuropathic pain are complex and involve peripheral and central pathophysiological phenomena. Proinflammatory tumour necrosis factor α (TNF-α) and TNF-α receptor 1, which are markers of inflammation, contribute to neuropathic pain. The purpose of this experimental study was to evaluate the effect of curcumin on diabetic pain in rats. We tested 24 rats with diabetes induced by a single intraperitoneal injection of streptozotocin and 24 healthy control rats. Twelve rats in each group received 60 mg/kg oral curcumin daily for 28 days, and the other 12 received vehicle. On days 7, 14, 21, and 28, we tested mechanical allodynia with von Frey hairs and thermal hyperalgesia with radiant heat. Markers of inflammation in the spinal cord dorsal horn on day 28 were estimated with a commercial assay and Western blot analysis. Compared to control rats, diabetic rats exhibited increased mean plasma glucose concentration, decreased mean body weight, and significant pain hypersensitivity, as evidenced by decreased paw withdrawal threshold to von Frey hairs and decreased paw withdrawal latency to heat. Curcumin significantly attenuated the diabetes-induced allodynia and hyperalgesia and reduced the expression of both TNF-α and TNF-α receptor 1. Curcumin seems to relieve diabetic hyperalgesia, possibly through an inhibitory action on TNF-α and TNF-α receptor 1.
Summary
The efficiency of various techniques pulsed electric field (PEF), ultrasound (US), high‐pressure microfluidisation (HPMF), hydrochloric acid (HCl) and ionic liquids (ILs) for cell wall disruption in astaxanthin extraction from Haematococcus pluvialis was compared. The results indicated that ILs, HCl and HPMF treatment were shown the most efficient for cell disruption with more than 80% astaxanthin recovery. While the cell wall integrity of H. pluvialis cyst cell was less affected by US and PEF treatment. It was found that imidazolium‐based ILs showed the greater potential for cell disruption than pyridinium‐based and ammonium‐based ILs. Among all the ILs examined, 1‐butyl‐3‐methylimidazolium chloride ([Bmim] Cl) exhibited efficient cell disruption and capability of astaxanthin recovery at mild condition (pretreatment with 40% IL aqueous solution at 40 °C, followed by extraction with methanol at 50 °C) without extensive energy consumption and special facility requirement. In addition, recyclability of ILs was excellent.
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