In vitro characterization of an injectable in situ forming composite system for bone reconstruction

none7siInjectable in situ forming composite scaffolds (ISFcG) have been prepared combining bovine bone substitute granules with a biodegradable and biocompatible thermogelling polymeric solution (chitosan). The presence of the organic component affects both physico-chemical features of ISFcG, as porosity, interconnectivity, mechanical properties and biofunctionality. The high water retention ability and the hydrophilic nature of the ISFcG polymer matrix promote the attachment and the infiltration of cells into the matrix and their growth. The polymeric component of ISFcG was susceptible to degradation during the in vitro incubation in simulated physiological conditions (DMEM pH 7.4, 37 C). The degradation products did not present remarkable toxicity level, as the MTT data resulted to be constant. The stability study showed an excellent in vitro physical stability even after mechanical stress. These features make the ISFcG based on chitosan and bovine bone substitute granules an excellent injectable composite scaffold for bone tissue regeneration.Dorati, R.; Colonna, C.; Genta, I.; De Trizio, A.; Modena, T.; Klöss, H.; Conti, B.Dorati, Rossella; Colonna, Claudia; Genta, Ida; DE TRIZIO, Antonella; Modena, Tiziana; Klöss, H.; Conti, Bic

Effect of SH-, NH2- and COOH-site group reagents on the transport processes in the proximal convolution of the rat kidney

The effects of site group reagents were tested on the following transport processes of the proximal convolution. Isotonic Na+ absorption, evaluated by the shrinking droplet procedure, histidine and glucose transport, evaluated by measuring the respective transtubular concentration difference at zero substance and water net flux. The test substances were applied either by continuous microperfusion of the peritubular capillaries or by luminal perfusion prior to the transport tests or by addition to the luminal test solution. The SH reagents (0.2 mM) N-ethylmaleimide,p-chloromercuribenzoate (pCMB) 3,6-bis-(acetatomercurimethyl)dioxane and Mersalyl (Salyrgane) caused 50% inhibition of the isotonic Na+ absorption in approximately 1.5 min when applied to the capillary perfusate. The same effect was reached in 2–3 min by 0.2 mMp-chloromercuriphenylsulfonate, benzamido-4-iodo-acetylstilbene-2,5-disulfonate and 2,2′-dihydroperoxy-2,2′-dibutylperoxide. However, the large molecular SH reagentspCMB-dextran T10 and benzoxanthene-3,4-dicarboxylic-N-iodoacetyloligoprolyl-2-aminoethylimid, did not inhibit the isotonic Na+ absorption. If an inhibitory effect was observed on the Na+ transport its onset was faster, when the substance was applied from the blood site than when it was given from the tubular lumen. Because SH reagents inhibit the isotonic Na transport faster when applied from the blood side, and because SH reagents with MW up to 690 are inhibitory whereas larger ones with MW over 1700 are not, it seems that they exert their inhibitory action on SH groups located a) predominantly on the blood side and b) deep within the membrane and not at the surface. Histidine- and glucose transport was inhibited only when the sodium transport was inhibited considerably. The oxygen consumption of teased kidney slices is not inhibited by 0.2 mMpCMB or Mersalyl within 10 min, but it is inhibited considerably by 1 mM of these substances in the same period of incubation time. The COOH reagents N,N′-carbonyl-diimidazole and N-ethyl-N′-(3-dimethyl-aminopropyl)carbodiimid (10 mM) and the NH2 reagents 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid, 2 Na+ (SITS) (1 mM) as well as danslychloride (applied from the lumen at 5 mM in paraffin oil) did not inhibit the isotonic Na+ absorption

HematoWork: A Knowledge-Based Workflow System for Distributed Cancer Therapy

The domain of hemato-oncology is characterized by a complex and data-intensive treatment and the involvement of geographically distributed institutions (e.g. oncological ward, central commission, external panels) in the context of protocol-directed trials. Current research efforts in this domain (e.g. [1-3]) focus on specialized subtasks such as chemotherapy calculation and toxicity monitoring, but fail to support inter-application data flow and coordination aspects which have been identified as essential for integration in heterogeneous and distributed clinical environments (e.g. [4,5]). Therefore, at Leipzig University, the distributed workflow system HEMATOWORK, which has explicit knowledge about the oncological treatment and the associated communication paths between the involved institutions, is currently developed. In particular, HEMATOWORK intends to support the following basic tasks: Treatment Functionality: This core functionality of HEMATOWORK covers therapy management and diagnostic monitoring, and is achieved through specialized applications (e.g. for calculating chemotherapy dosages) and databases coordinated by HEMATOWORK. Intra-hospital Communication Functionality: As every specialized medical workflow system inherently requires services of other local sections and departments