Cryohemostasis of uncontrolled hemorrhage from liver injury

Iodine Immobilized UiO-66-NH2 Metal-Organic Framework as an Effective Antibacterial Additive for Poly(ε-caprolactone)

Iodine has been widely used as an effective disinfectant with broad-spectrum antimicrobial potency. However, the application of iodine in an antibacterial polymer remains challenging due to its volatile nature and poor solubility. Herein, iodine immobilized UiO-66-NH2 metal-organic framework (MOF) (UiO66@I2) with a high loading capacity was synthesized and used as an effective antibacterial additive for poly(ε-caprolactone) (PCL). An orthogonal design approach was used to achieve the optimal experiments' conditions in iodine adsorption. UiO66@I2 nanoparticles were added to the PCL matrix under ultrasonic vibration and evaporated the solvent to get a polymer membrane. The composites were characterized by SEM, XRD, FTIR, and static contact angle analysis. UiO-66-NH2 nanoparticles have a high iodine loading capacity, up to 18 wt.%. The concentration of iodine is the most important factor in iodine adsorption. Adding 0.5 wt.% or 1.0 wt.% (equivalent iodine content) of UiO66@I2 to the PCL matrix had no influence on the structure of PCL but reduces the static water angle. The PCL composites showed strong antibacterial activities against Staphylococcus aureus and Escherichia coli. In contrast, the same content of free iodine/PCL composites had no antibacterial activity. The difference in the antibacterial performance was due to the different iodine contents in the polymer composites. It was found that MOF nanoparticles could retain most of the iodine during the sample preparation and storage, while there was few iodine left in the free iodine/PCL composites. This study offers a common and simple way to immobilize iodine and prepare antibacterial polymers with low antiseptic content that would reduce the influence of an additive on polymers' physical properties.

Zeolitic imidazolate framework-8/Bacterial Cellulose Composite for Iodine Loading and Its Antibacterial Performance

Bacterial cellulose (BC), produced by bacteria and fungi, is a promising material in the biomedical field. However, non-antibacterial activity limits its broad applications. Herein, antibacterial composites (BC/ZIF-8-Iodine) were prepared by...

Controlled release of iodine from cross-linked cyclodextrin metal-organic frameworks for prolonged periodontal pocket therapy

Effective therapeutic system to periodontitis was designed using cross-linked cyclodextrin metal-organic framework (COF) as carrier for iodine and further suspended in hydroxyethyl cellulose gel as I2@COF-HEC hydrogel. Inclusion of iodine within the COF was demonstrated by SR-FTIR spectral and characteristic DSC and TGA changes. Molecular modelling identified the interaction of iodine with both COF central cavity and individual cyclodextrin moieties of COF. In vitro results of study demonstrated that iodine release in artificial saliva from I2@COF-HEC hydrogel could be extended up to 5 days, which was slower than I2@COF particles. Using an in vivo rat model of periodontitis, micro-computed tomography of alveolar bone morphology demonstrated that I2@COF-HEC hydrogel showed similar effects in decreasing periodontal pocket depth and alveolar bone resorption to minocycline ointment, a periodontitis antibiotic. The I2@COF-HEC hydrogel is a novel local delivery device of iodine as a broad spectrum antimicrobial use for treatment of periodontitis.

Incidence and clinical sequelae of portal and hepatic venous thrombosis following percutaneous cryoablation of liver tumors

PURPOSE

To assess the incidence and sequelae of portal and hepatic venous thrombosis after percutaneous cryoablation of hepatic tumors.

METHODS

From November 1998 through December 2010, 223 hepatic tumors were cryoablated during 170 ablation procedures in 135 patients. 24-h post-procedure MR images were reviewed retrospectively by two abdominal radiologists in consensus to identify tumor ablations that developed one or more new portal or hepatic venous thromboses in or outside the ablation zone. On follow-up MRI and CT examinations the outcomes of thromboses were classified as resolved, partially recanalized, persistent, or propagated.

RESULTS

Venous thrombosis developed in association with 54 (24%) of 223 tumor ablations treated during 53 (31%) ablation procedures in 39 (28.8%) patients (15 women, 24 men; age range 40-82 years, mean 59 years). Of these 54 thromboses, 49 (91%) were located in portal vein branches, four (7%) in both portal and hepatic vein branches, and one (2%) in a hepatic vein branch. Thrombosed veins were outside but abutted the ablation zone in 36 (66.7%), and within it in 18 (33.3%). On follow-up imaging (n = 49), thrombi resolved in 29 (59%), partially recanalized in two (4%), persisted in 18 (37%) and propagated from sub-segmental or segmental branches to the left or right portal branches in five (10%). No thrombus propagated to the main portal vein or inferior vena cava.

CONCLUSION

Portal and hepatic vein branch thromboses are common in small branches following percutaneous cryoablation of hepatic tumors and most resolve spontaneously without sequelae.

Experimental cryosurgery investigations in vivo

Cryosurgery is the use of freezing temperatures to elicit an ablative response in a targeted tissue. This review provides a global overview of experimentation in vivo which has been the basis of advancement of this widely applied therapeutic option. The cellular and tissue-related events that underlie the mechanisms of destruction, including direct cell injury (cryolysis), vascular stasis, apoptosis and necrosis, are described and are related to the optimal methods of technique of freezing to achieve efficacious therapy. In vivo experiments with major organs, including wound healing, the putative immunological response following thawing, and the use of cryoadjunctive strategies to enhance cancer cell sensitivity to freezing, are described.

The application of cryosurgery in the treatment of lung cancer

Lung cancer is the commonest cause of cancer death, with a very poor survival rate. By the time of diagnosis, most cases are at an advanced stage and about 30% present with symptoms caused by central endobronchial obstruction. Endobronchial cryosurgery is an effective technique, which can be used to relieve tracheobronchial obstruction caused by lung cancer. This report describes the technique, using a nitrous oxide cooled cryoprobe, inserted through a bronchoscope, to remove the obstruction and reopen the airway. In this study, 476 consecutive patients (mean age 68.3 years, M:F ratio 1.9:1) with obstructive tracheobronchial tumours underwent a mean of 2.4 cryosurgical treatments. Their TNM staging was, stage II 6.7%, IIIa 21.0%, IIIb 23.9%, IV 48.4%. Improvement in symptom quantification was found with 76.4, 69.0, 59.2, and 42.6% of symptomatic patients for haemoptysis, cough, dyspnoea, and chest pain, respectively. Mean values for respiratory function improved from 1.38 to 1.41 litres for FEV1 and 1.91 to 2.04 litres for FVC (p </= 0.0001). Mean performance status improved from 59.6 to 75.2 for Karnofsky scale and 3.04 to 2.20 for the WHO scale and the complication rate was 3.5% of treatments. The Kaplan-Meier median survival was 8.2 months and 1- and 2-year survival 38.4 and 15.9%, respectively. Survival analysis suggested a possible survival advantage over alternative palliative techniques. Endobronchial cryosurgery provides a safe and effective method for the palliation of otherwise inoperable lung cancer. It has advantages over other methods in terms of safety, cost, and a low complication rate. Cryosurgery can be repeated as often as required.

Intraosseous Hypertonic Saline Solution for Resuscitation of Uncontrolled, Exsanguinating Liver Injury in Young Swine

Fluid resuscitation administered before hemorrhage control for trauma victims sustaining blunt abdominal injury is controversial. Prehospital fluid resuscitation is limited by difficulty in delivering large volumes of fluid in the field and time delays associated with gaining vascular access. Venous access is often a clinical dilemma in severely hypovolemic children. Intraosseous infusion is considered a useful technique for the administration of fluids in emergency situations when peripheral intravascular access is not possible. This study investigated the effectiveness of intraosseous versus intravenous infusion of hypertonic saline solution in an uncontrolled hemorrhagic shock swine model. We also tested the effect of the different sites of infusion on the intra-abdominal bleeding. Relevant hemodynamic parameters were monitored and blood samples were collected. After liver injury, 20 anesthetized immature pigs were randomized to three groups: intraosseous access, intravenous access and control. After 20 min of uncontrolled hemorrhage, the hypertonic saline solution begins in the intraosseous access and intravenous access groups of animals. Thirty minutes later, the animals were killed and intra-abdominal blood loss was measured. All the pigs presented lower pressures and lower cardiac output after 20 min of hemorrhagic shock. The intravenous and intraosseous access groups did not show a better hemodynamic performance after 10 min of fluid resuscitation. At the end of the experiment, all animals were hemodynamically similar without an improved answer to a fluid resuscitation. There were no significant differences between groups regarding intra-abdominal blood loss. It was concluded that the hypertonic saline solution in this experimental model did not promote hemodynamic improvement and there were no differences between the two sites of fluid resuscitation regarding intra-abdominal blood loss.

Early use of recombinant factor VIIa improves mean arterial pressure and may potentially decrease mortality in experimental hemorrhagic shock: a pilot study

BACKGROUND

Recombinant factor VIIa (rFVIIa) is used for treatment of bleeding episodes in hemophilia patients who develop inhibitors to factors VIII and IX. We tested the hypothesis that administration of rFVIIa early after injury would decrease bleeding and improve survival after experimental hepatic trauma.

METHODS

Anesthetized swine were cannulated for blood sampling and hemodynamic monitoring. Avulsion of left median lobe of the liver induced uncontrolled hemorrhage. After a 10% reduction of mean arterial pressure, animals were blindly randomized to receive intravenous rFVIIa (180 microg/kg) (n = 6) or placebo (n = 7).

RESULTS

Mortality was 43% (three of seven) in controls versus 0% with rFVIIa (p = 0.08, chi2). Significantly shorter prothrombin time and higher mean arterial pressures were observed in the rFVIIa group.

CONCLUSION

Intravenous administration of rFVIIa early after induction of hemorrhage shortens prothrombin time and improves mean arterial pressure. A trend toward improved survival was observed.