Ionic liquid modulation of swelling and LCST behavior of N-isopropylacrylamide polymer gels.

The physicochemical properties of free-standing cross-linked poly(N-isopropylacrylamide) (pNIPAAM) gels, generated in the presence of the Ionic liquids (ILs), 1-ethyl-3-methylimidazolium [C2mIm](+) salts of ethylsulfate [EtSO4](-), dicyanamide [DCA](-), bis(trifluoromethylsulfonyl)imide [NTf2](-), and trihexyltetradecylphosphonium dicyanamide ([P(6,6,6,14)][DCA]) are described. The Lower Critical Solution Temperature (LCST) of the resulting ionogel was found to vary between 24-31 °C. The behaviour of swelling is found to be as high as 31.55% (±0.47, n = 3) from the initial dehydrated state, while 28.04% (±0.42, n = 3) shrinking from the hydrated swollen state is observed. For ionogels based on the [DCA](-) anion an unexpected complete loss of the shrinking behaviour occurs, attributed to water interactions with the nitrile group of the [DCA](-) anion. Scanning Electron Microscopy also reveals distinct morphological changes, for example [C2mIm][EtSO4] displays a highly porous, nodule type morphology, efficiently pre-disposed for water uptake.

The use of state-of-the-art haemostatic materials in gastrointestinal surgery.

Haemostatic materials such as: gelatine sponges, oxygenated cellulose meshes, tissue sealants, collagen matrices with human thrombin and fibrinogen are gaining on popularity in gastrointestinal surgery, especially in colorectal surgery. We searched for available scientific publications in the Pubmed and Cochrane database on the use of individual hemostatic materials in the field of gastrointestinal surgery. The analysis focused on the assessment of the safety of the use of individual materials in terms of the rate of bleeding complications and the rate of anastomotic leakage cases. The use of haemostatic materials has for years been a recognized method of reducing the rate of intra- and postoperative complications, both in gastrointestinal surgery and in other surgical specialties. Based on the available studies, it can be concluded that the use of hemostatic materials such as matrices, sponges and adhesives in gastrointestinal surgery, even in patients at high risk of anastomotic leakage and bleeding complications, reduces the incidence of complications. The growing popularity of haemostatics and sealants in surgery means that they are currently used in a wide range of indications, and surgeons are more and more willing to use them even in case of standard surgical procedures, which is reflected in the available studies. Choosing a haemostat should be a conscious decision, taking into account the site and type of bleeding, mechanism of action, ease of use, efficacy, safety, and price, among others.

[Breast carcinoma and anaplastic gastric carcinoma with pleural metastases in patient after mastectomy 30 years ago]. / Przypadek wspólistnienia raka sutka z rakiem anaplastycznym zoladka z przerzutami do oplucnej u chorej po mastektomii przed 30 laty.

We describe a case of two simultaneous malignancies--anaplastic gastric carcinoma with pleural metastases and left breast carcinoma. These malignancies were recognized in 78-year old woman after right mastectomy performed 30 years ago. Additionaly, during diagnostic procedures rectal polypus found during colonoscopy occurred to be adenoma tubulovillosum. Her parents died from malignancies--mother from gastric cancer and father from pulmonary carcinoma. One should remember that there is always possibility of simultaneous development of more than one primary malignancies in one patient and neoplastic disease is an important cancer risk factor. This observation confirms the important role of genetic factors in the pathogenesis of malignant diseases.

Photoswitchable ratchet surface topographies based on self-protonating spiropyran-NIPAAM hydrogels.

In this work, self-protonating spiropyran-based poly(N-isopropylacrylamide) polymer networks are prepared. These photoresponsive hydrogel coatings can change their surface topography upon exposure with visible light in a neutral environment. Photoresponsive surface-constrained films have been fabricated for which the swelling behavior can be controlled in a reversible manner. In a first step, symmetrical switchable surface topologies with varying cross-link density are obtained by polymerization-induced diffusion. Under light exposure, the areas with low cross-link density swell more than the areas with high cross-link density, thus forming a corrugated surface. Asymmetric ratchet-like photoresponsive surfaces have been prepared on prestructured asymmetric substrates. As a result of thickness variation of the surface-confined hydrogel layer, an asymmetric swelling behavior is obtained. Depending on the cross-link density of the hydrogel, it is possible to switch between a ratchet and flat surface topography or even an inverse ratchet surface by light.

Thermoresponsive poly(ionic liquid) hydrogels.

A new series of LCST ILs have been copolymerised with crosslinkers of varying length to afford the first ever thermoresponsive poly(ionic liquid)-based hydrogels. These hydrogels exhibit surprisingly broad LCST and volume transition behaviour compared to standard thermoresponsive gels and linear ILs.