Influences of opioids and nanoparticles on in vitro wound healing models

For efficient pain reduction in severe skin wounds, topical opioids may be a new option – given that wound healing is not impaired and the vehicle allows for slow opioid release, since long intervals of painful wound dressing changes are intended. We investigated the influence of opioids on the wound healing process via in vitro models, migration assay and scratch test. In fact, morphine, hydromorphone, fentanyl and buprenorphine increased the number of migrated HaCaT cells (spontaneously transformed keratinocytes) twofold. In the scratch test, morphine accelerated the closure of a monolayer wound (scratch). As possible slow release application forms are nanoparticulate systems like solid lipid nanoparticles (SLN) and dendritic core-multishell (CMS) nanotransporters, we evaluated the effect of unloaded nanoparticles on HaCaT cell migration, too. CMS nanotransporters did not inhibit migration, SLN even enhanced it (twofold). Applying morphine plus unloaded nanoparticles reduced morphine effects possibly due to uptake into CMS nanotransporters and adsorption to the surface of SLN. In contrast to SLN, TGF-β1 was taken up by CMS nanotransporters, too. Both nanoparticles are tolerable by skin and eye as derived from Episkin-SM^TM skin irritation test and HET-CAM assay. No acute toxic effects were observed either. In conclusion, opioids as well as the investigated nanoparticulate carriers conform the essential conditions for topical pain reduction.     

Dobrava-Belgrade Virus Spillover Infections, Germany

We present the molecular identification of Apodemus agrarius (striped field mouse) as reservoir host of the Dobrava-Belgrade virus (DOBV) lineage DOBV-Aa in 3 federal states of Germany. Phylogenetic analyses provided evidence for multiple spillover of DOBV-Aa to A. flavicollis, a crucial prerequisite for host switch and genetic reassortment.     

Cytotoxic and genotoxic effects of matrices for cartilage tissue engineering

Customizing auricles with biodegradable polyurethane colonized with autologous chondrocytes as an approach for tissue engineering cartilage transplants has been suggested for the reconstruction of the external ear to repair auricular deformities. Dextrose, triethanolamine and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG) are matrices of an open-pored polyurethane three-dimensional scaffold. After release from the polymer, these compounds can be absorbed into the human organism. Therefore, cytotoxic effects on human chondrocytes and lymphocytes and genotoxic effects on human lymphocytes were determined. Propidium iodide and fluoresceine diacetate staining as well as quantitative proliferations testing with EZ4U served to detect cytotoxic effects on chondrocytes. In lymphocytes cytotoxicity was checked by trypan blue staining and the alkaline single cell microgel electrophoresis (Comet) assay was used to study genotoxic effects. Dose-dependent cytotoxicity and genotoxicity of the matrices could be shown. Concentrations up to 4.25 mg/ml for dextrose, 0.15 mg/ml for PEG-PPG-PEG and 0.9 mg/ml for triethanolamine did not show cytotoxic effects in chondrocytes or genotoxic effects in lymphocytes. These data suggest that dextrose, triethanolamine and PEG-PPG-PEG could be safely used if scaffolds made of open-pored polyurethane do not release these compounds at a rate giving higher concentrations at the site of implantation or in body fluids, respectively.     

Rapid detection of JMH antibodies with recombinant Sema7A (CD108) protein and the particle gel immunoassay

BACKGROUND: At present, identification of antibodies against the high-prevalence JMH antigen is difficult and limited to reference laboratories having panels of rare red blood cell (RBC) specimens in stock. Here, a novel method is described for detection of anti-JMH with particles coated with recombinant semaphorin 7A (Sema7A, CD108), the protein that carries the JMH blood group antigens. STUDY DESIGN AND METHODS: Recombinant Sema7A protein was generated and coupled onto superparamagnetic particles coated with streptavidin. The coated particles were tested in the presence of different serum and plasma samples (11 anti-JMH, 20 other antibodies, and 50 samples from nonimmunized blood donors) with the particle gel immunoassay and flow cytometry. RESULTS: Sema7A-coated particles reacted with all 11 samples containing anti-JMH, but not with samples lacking anti-JMH. In addition, the anti-JMH agglutination scores were higher with Sema7A-coated particles than with JMH-positive RBCs in all cases. CONCLUSION: Recombinant blood group proteins have the potential to replace RBCs as antigen carriers for identification of certain RBC alloantibodies.     

Impaired Hyperglycemia-Induced Delay in Gastric Emptying in Patients With Type 1 Diabetes Deficient for Islet Amyloid Polypeptide

OBJECTIVE—Slowing of gastric emptying by hyperglycemia, a physiological response to minimize postprandial hyperglycemia, may be impaired in patients with type 1 diabetes. The causes and consequences on glucose homeostasis are unknown.RESEARCH DESIGN AND METHODS—Consequences of euglycemia- and hyperglycemia-induced changes in gastric emptying on postprandial glucose fluxes and excursions were studied in 10 healthy subjects and 15 type 1 diabetic subjects after ingestion of a mixed meal using the double isotope approach ([6,6-²H₂] and [1-¹³C]glucose) and scintigraphic measurements of gastric emptying.RESULTS—Gastric emptying was greater in type 1 diabetic subjects (90–120 min, P < 0.03), and 50% retention times were comparable in healthy subjects and type 1 diabetic subjects (167 ± 8 vs. 152 ± 10, P = 0.32). Hyperglycemia markedly delayed gastric emptying in healthy subjects but did not alter it in type 1 diabetic subjects (50% retention time 222 ± 18 vs. 167 ± 8 min, P = 0.003 and 148 ± 9 vs. 152 ± 10 min, P = 0.51). Plasma islet amyloid polypeptide (IAPP) increased approximately fourfold in healthy subjects (P < 0.001), whereas it was undetectable in type 1 diabetic subjects. IAPP replacement, using the analog pramlintide, in type 1 diabetic subjects slowed gastric emptying to a comparable extent, as did hyperglycemia in healthy subjects (P < 0.14), and greatly reduced postprandial hyperglycemia (P < 00.1). Meal-derived glucose appearance in plasma (10.7 ± 0.5 vs. 6.8 ± 0.7 μmol · kg⁻¹ · min⁻¹, P < 0.001) was reduced, and splanchnic glucose sequestration increased (14.0 ± 3.0 vs. 25.0 ± 6.0%, P = 0.04).CONCLUSIONS—In patients with type 1 diabetes the ability to delay gastric emptying in response to hyperglycemia is impaired. This impairment contributes to exaggerated rates of meal-derived glucose appearance and, ultimately, postprandial glucose excursions.The importance of insulin and glucagon in maintaining postprandial glycemic excursions within a narrow range is well established (1). However, alterations in gastric emptying, another potentially important factor (2), are not generally considered to be of clinical significance for postprandial hyperglycemia in diabetes unless diabetes late complications, such as gastroparesis, have emerged (3,4).Gastroparesis is a relatively rare diabetes late complication resulting from irreversible intestinal nerve damage (5) and has to be distinguished from the physiological inhibitory effects of acute hyperglycemia on gastric motility (6,7). The latter has been proposed as a defense mechanism to minimize postprandial hyperglycemia by reducing the rate of efflux of glucose into the circulation from the gut (8). This process may be of special importance for patients with type 1 diabetes because they have been reported to have a reduced ability to delay gastric emptying in response to hyperglycemia (9).The pancreatic β-cell hormone islet amyloid polypeptide (IAPP) is cosecreted with insulin in a fixed molar ratio (10) and reduces gastric emptying. Thus, patients with type 1 diabetes even without concomitant enteric neuropathy should have increased rather than delayed rates of gastric emptying, because they are IAPP deficient (11). Accordingly, the present studies were undertaken to test the hypothesis that impairment in hyperglycemia-induced delay in gastric emptying should result in greater meal-derived glucose appearance in the systemic circulation and thus should contribute to postprandial hyperglycemia in patients with type 1 diabetes.