No abstract

Cell colonization of the surrounding environment is a very significant process in both physiological and pathological events. In order to understand the tissue regeneration process and thereby provide guidance principles for designing new biomaterials, it is of paramount importance to study the cell colonization in the presence of physical, chemical, and biological cues. Flat "gradient" materials are generally used with this purpose. Three dimensional gradient scaffolds mimicking more precisely the situation in vivo are somewhat more complex to fabricate and characterize. Scaffolds for Tissue Engineering (TE) made of hydrophobic synthetic polymers do not allow good cell colonization: far from their periphery, in fact, internal cell colonization is usually low. In this research poly-ε caprolactone (PCL) scaffolds have been "decorated" with chemical gradients both on top and along their thickness by means of cold plasma processes, in order to improve cell colonization of their core. Plasma treatments with a mixture of argon and oxygen (Ar/O), as well as plasma deposition of differently cross-linked poly(ethylene oxide) (PEO)-like coatings, have been performed. This study establishes that cross-linked PEO-like domains interspaced with native PCL ones deposited only on top of the scaffold (i.e., coating that penetrates less than 300 μm inside the scaffold) are more effective in promoting cell colonization across the scaffolds than the other tested materials including superhydrophilic samples and that ones produced by tested double step approaches. Last but not least, one result of this research is that, in the case of plasma coatings with low deposition rates and porous materials with a low pore interconnectivity, it is possible to improve penetration of low pressure plasma active species inside the scaffold's core thorough a pretreatment of the porous materials (i.e., penetration up to 4500 mm far from topside).

BackgroundLimitations of autogenous grafts have dictated the need for development of new biomaterials that can serve as allografts. A paradigm shift directed manufacturers to revert to nature in the search for such allografts. This study aimed to evaluate an eggshell-based supplement, Membrell’s® BONEhealth Plus D3 & K2, indicated to support bone mineral density, as a natural bone graft material.MethodsTwelve 5 × 10 × 1 mm full-thickness cranial bone defects were created in six adult male New Zealand rabbits. Six defects were filled with Membrell’s® BONEhealth™ Plus D3 & K2, and the others were left empty as control. The animals were sacrificed 14 days postoperatively. The defects were dissected and prepared for histological assessment. Bone formation was compared both qualitatively and quantitatively. The area percent of newly-formed bone was evaluated in five successive regions using image analysis. Statistical analysis was performed using unpaired t-test. Differences between the two groups were considered significant at p ≤ 0.05.ResultsCranial bone defects filled with the nano-sized eggshell powder “Membrell’s® BONEhealth™ Plus D3 & K2” revealed significantly higher levels of osteoid, newly-formed, regularly-arranged bone trabeculae in the center of the defects (47.37% ± 1.12) compared to the control defects (21.6% ± 4.92), which revealed no bone formation. A rapid rate of resorption of the nano-sized eggshell powder and consequently a rapid osteogenic effect was evident.ConclusionsThe eggshell-based graft powder, Membrell’s® BONEhealth™ Plus D3 & K2, is a biocompatible material which has the potential to enhance new bone formation.

The interplay between plasma processes and the biological environment is a\ud long and intriguing story that spans different applications, from surface modification of biomaterials\ud to the direct interaction of plasma with cells. This makes plasma processes very\ud powerful tools in such biomedical fields as tissue engineering and sterilization, which are\ud much different than the typical field in which plasmas are used. In vitro cell culture experiments\ud represent the best way to fully understand the more subtle and fundamental interactions\ud between the chemical species produced by glow discharge and cells. Among the different kind\ud of cells that can be used, cell lines allow high reproducibility and control of results. This article\ud reviews 3 main items, ranging from low-pressure plasma modifications of 2- and 3-dimensional\ud materials to dielectric barrier discharges directly on cells, with respect to the authors’\ud scientific work

he cotton leafworm, Spodoptera littoralis (Boisd.) is very polyphagous insect against the most economic plants all over the world. The traditional synthetic chemical insecticides had dramatic effect on the living organisms including man. Anti-juvenile hormones; precocene II effect on the cotton leafworm, Spodoptera littoralis were assayed under laboratory conditions. (PrecoceneII (6,7-dimethoxy-2,2dimethylchromene) was the main constituent isolated from Ageratum houstonianum plant. The compound caused toxicity against the larvae with (LC10 was 5.59 mg/l), (LC25 was 24.69 mg/l) and (LC50 was 128.53 mg/l). There was some morphogenic effect obtained due to effect of precoceneII on larvae, pupae and adult stages. On the other hands the biochemical analysis of the cotton leafworm revealed that precocene II caused significant increase in chitinase, protease and total carbohydrates with (17.32, 50.17 and 36.85 %), respectively comparison to control.