Mechanical and morphological responses of osteoblast-like cells to two-photon polymerized microgrooved surfaces.

Microgrooved surfaces are recognized as an important strategy of tissue engineering to promote the alignment of bone cells. In this work, we have investigated the mechanical and morphological aspects of osteoblasts cells after interaction with different micro-structured polymeric surfaces. Femtosecond laser writing technique was used for the construction of circular and parallel microgrooved patterns in biocompatible polymeric surfaces based on pentaerythritol triacrylate. Additionally, we have studied the influence of the biocompatible TiO2 nanocrystals (NCs) related to the cell behavior, when incorporated to the photoresin. The atomic force microscopy technique was used to investigate the biomechanical reaction of the human osteoblast-like MG-63 cells for the different microgroove. It was demonstrated that osteoblasts grown on circular microgrooved surfaces exhibited significantly larger Young's modulus compared to cells sown on flat films. Furthermore, we could observe that TiO2 NCs improved the circular microgrooves effects, resulting in more populated sites, 34% more elongated cells, and increasing the cell stiffness by almost 160%. These results can guide the design and construction of effective scaffold surfaces with circular microgrooves for tissue engineering and bone regeneration.

Modulation of inflammatory processes by leaves extract from Clusia nemorosa both in vitro and in vivo animal models.

The present study was carried out to investigate the anti-inflammatory effect of the hexane extract of the leaves from Clusia nemorosa G. Mey, called HECn, using carrageenan-induced mice pleurisy and cotton pellet-induced mice granuloma. Additionally, the ability of HECn to affect both neutrophil migration as viability was investigated by use of the Boyden chamber assay and flow cytometry, respectively. The HECn significantly inhibited exudation, total leukocytes and neutrophils influx, as well as TNFα levels in carrageenan-induced pleurisy. However, the extract not suppressed the granulomatous tissue formation in the cotton pellet-induced granuloma test. Experiments performed in vitro revealed that HECn on human neutrophils inhibited a dose-dependent manner the CXCL1-induced neutrophil chemotaxis. Furthermore, HECn also inhibited the chemoattraction of human neutrophils induced by formyl-methionyl-leucyl-phenylalanine (fMLP), leukotriene B4 (LTB4) and platelet activating factor (PAF) in a Boyden chamber. However, this same treatment not was able to induce apoptosis. The results obtained in this study showed that the extract from leaves of C. nemorosa possess a potent inhibitory activity in acute model of inflammation, being the effects mediated, in part, by inhibition of neutrophil responsiveness. These results indicate that C. nemorosa could be a good source for anti-inflammatory compounds.

Antinociceptive activity of aqueous extract of Bowdichia virgilioides in mice.

Bowdichia virgilioides Kunth (Family Fabaceae) is a plant that is distributed widely in the tropical and subtropical regions of the world. In the northeast region of Brazil, where B. virgilioides is called "sucupira-preta," the stem bark is used in folk medicine to treatment of inflammatory and painful diseases. This study aimed to evaluate the antinociceptive activity of the aqueous extract of the dried stem bark of B. virgilioides. The aqueous extract of B. virgilioides in doses of 50, 100, 200, and 400 mg/kg was administered orally 1 hour prior to pain induction. Only the doses of 200 and 400 mg/kg produced an inhibition by 61% and 74%, respectively, in the number of abdominal writhings induced by acetic acid. This antinociceptive effect was not reversed by pretreatment with naloxone, indicating that the effect is not associated with the activation of opioid receptors. In the formalin test, using the two highest doses, the extract had no effect in the first phase but produced an analgesic effect on the second phase with the inhibition of licking time (P < .001). In the hot plate test, no effect was seen at the dose of 400 mg/kg p.o. Our findings show that B. virgilioides contains pharmacologically active constituents that possess antinociceptive activity justifying its popular therapeutic use in treating conditions associated with the painful conditions.