Conference Scene: From innovative polymers to advanced nanomedicine: Key challenges, recent progress and future perspectives

Recent developments in polymer-based controlled delivery systems have made a significant clinical impact. The second Symposium on Innovative Polymers for Controlled Delivery (SIPCD) was held in Suzhou, China to address the key challenges and provide up-to-date progress and future perspectives in the innovation of polymer-based therapeutics. At SIPCD, a stimulating panel discussion was introduced for the first time on “What is the future of nanomedicine?” This report highlights the most recent research and developments in biomedical polymers and nanomedicine made by 29 invited scientists from around the world, as well as important issues regarding clinical advancements of nanomedicine conferred during the panel discussion

An in vitro study of the adhesion of blood platelets onto vascular catheters. Part I

The adhesion of human blood platelets onto vascular catheters was studied using a specially designed perfusion chamber. Polyurethane catheters were exposed to citrated human blood for different periods (up to 20 min) and at different wall shear rates (190, 260, 330 sec-1). The rate of platelet adhesion was determined using 111In-labeled platelets, while the morphology of adhering platelets was investigated using scanning electron microscopy. A linear increase in platelet adhesion was found within the first 10 min of perfusion, after which a plateau value was reached. The number of adhering platelets did not vary significantly with the shear rates applied, which may indicate that within the range of shear rates studied, the adhesion of platelets onto the catheter surface is mainly determined by the rate of the reaction between the platelets and the material surface. Catheters coated with a conjugate of heparin and albumin showed a four- to five-fold reduction in platelet adhesion as compared to uncoated catheters. This reduction in platelet adhesion was not only due to the presence of albumin moieties at the surface but also to the presence of heparin residues in the adsorbed albumin-heparin conjugate

Complement inhibitory and anticoagulant activities of fractionated heparins

Almost monodisperse heparin fractions (Mw/Mn < 1.1) were obtained by gel filtration of a commercial heparin. These fractions were assayed for anticoagulant activity (thrombin times and APTT), chromogenic anti-factor Xa activity, inhibitory activity for the human classical complement pathway, carboxyl group content and total sulfate content. Linear relationships were observed between the molecular weight of the heparin fractions and the anticoagulant activities as determined by thrombin time- and APTT-assay and the classical complement pathway inhibitory activity. On the other hand a hyperbolic-like relationship was observed between the molecular weight of the heparin fractions and the chromogenic anti-factor Xa activity. The heparin fractions did not show significant differences with respect to the carboxyl group and total sulfate content. Low- and high affinity heparin fractions were obtained by affinity chromatography using immobilized AT III. High- and low-affinity fractions greatly differed not only with respect to their APTT activity, but also where their complement-inhibitory activities were concerned. The latter in contrast to literature data available. These differences could not be explained by the observed differences in molecular weight of high and low affinity heparin respectively

Азовська операція Революційної Повстанської Армії України (махновців)

В історії України знайдеться не так вже й багато явищ та подій, які б значимістю та силою переросли рамки регіональної та національної історії і ставали повноправними надбаннями історії всесвітньої. Ще менше подібних подій та явищ існувало на рівні південноукраїнського регіону. І було б логічно, якби такі явища посилено досліджувались істориками, а результати досліджень ставали надбанням якомога ширшого загалу, що перетворювало б ці явища на бренд, який швидко вгадувався і запам’ятовувся будь-де. Проте в умовах сучасної України ми цього не спостерігаємо

Interaction of antithrombin III with preadsorbed albumin-heparin conjugates

The adsorption of antithrombin III (AT III) onto polystyrene surfaces preadsorbed with albumin or albuminheparin conjugates was studied using a two step enzyme immuno assay. When AT III-buffer solutions were used, the highest adsorption values were measured on high affinity albumin-heparin conjugate pretreated surfaces. Less AT III adsorption was found on nonfractionated albumin-heparin conjugate preadsorbed surfaces. AT III adsorption could also be detected on low affinity conjugate and albumin coated surfaces. When AT III was adsorbed from plasma or plasma dilutions with buffer, only AT III on surfaces preadsorbed with high affinity or nonfractionated albumin-heparin conjugate was found. These results demonstrate that the heparin moiety of the conjugate is directed to the solution phase whereas the albumin moiety contacts the polystyrene surfaca

Концепція сталого розвитку туризму в сучасних умовах

Мета статті – розробка основних положень концепції сталого розвитку туризму в регіоні

Alginate microspheres containing temperature sensitive liposomes (TSL) for MR-guided embolization and triggered release of doxorubicin

Objective The objective of this study was to develop and characterize alginate microspheres suitable for embolization with on-demand triggered doxorubicin (DOX) release and whereby the microspheres as well as the drug releasing process can be visualized in vivo using MRI. Methods and Findings For this purpose, barium crosslinked alginate microspheres were loaded with temperature sensitive liposomes (TSL/TSL-Ba-ms), which release their payload upon mild hyperthermia. These TSL contained DOX and [Gd(HPDO3A)(H2O)], a T1 MRI contrast agent, for real time visualization of the release. Empty alginate microspheres crosslinked with holmium ions (T2* MRI contrast agent, Ho-ms) were mixed with TSL-Ba-ms to allow microsphere visualization. TSL-Ba-ms and Ho-ms were prepared with a homemade spray device and sized by sieving. Encapsulation of TSL in barium crosslinked microspheres changed the triggered release properties only slightly: 95% of the loaded DOX was released from free TSL vs. 86% release for TSL-Ba-ms within 30 seconds in 50% FBS at 42°C. TSL-Ba-ms (76 ± 41 μm) and Ho-ms (64 ± 29 μm) had a comparable size, which most likely will result in a similar in vivo tissue distribution after an i.v. co-injection and therefore Ho-ms can be used as tracer for the TSL-Ba-ms. MR imaging of a TSL-Ba-ms and Ho-ms mixture (ratio 95:5) before and after hyperthermia allowed in vitro and in vivo visualization of microsphere deposition (T2*-weighted images) as well as temperature-triggered release (T1-weighted images). The [Gd(HPDO3A)(H2O)] release and clusters of microspheres containing holmium ions were visualized in a VX2 tumor model in a rabbit using MRI. Conclusions In conclusion, these TSL-Ba-ms and Ho-ms are promising systems for real-time, MR-guided embolization and triggered release of drugs in vivo