Alginate-hyaluronan composite hydrogels accelerate wound healing process.

In this paper we propose polysaccharide hydrogels combining alginate (ALG) and hyaluronan (HA) as biofunctional platform for dermal wound repair. Hydrogels produced by internal gelation were homogeneous and easy to handle. Rheological evaluation of gelation kinetics of ALG/HA mixtures at different ratios allowed understanding the HA effect on ALG cross-linking process. Disk-shaped hydrogels, at different ALG/HA ratio, were characterized for morphology, homogeneity and mechanical properties. Results suggest that, although the presence of HA does significantly slow down gelation kinetics, the concentration of cross-links reached at the end of gelation is scarcely affected. The in vitro activity of ALG/HA dressings was tested on adipose derived multipotent adult stem cells (Ad-MSC) and an immortalized keratinocyte cell line (HaCaT). Hydrogels did not interfere with cell viability in both cells lines, but significantly promoted gap closure in a scratch assay at early (1 day) and late (5 days) stages as compared to hydrogels made of ALG alone (p<0.01 and 0.001 for Ad-MSC and HaCaT, respectively). In vivo wound healing studies, conducted on a rat model of excised wound indicated that after 5 days ALG/HA hydrogels significantly promoted wound closure as compared to ALG ones (p<0.001). Overall results demonstrate that the integration of HA in a physically cross-linked ALG hydrogel can be a versatile strategy to promote wound healing that can be easily translated in a clinical setting.

Experimental infection of goats with an unusual strain of Mycoplasma mycoides subsp. capri isolated in Jordan.

Goats were infected experimentally with a mycoplasma (the "Irbid" strain) isolated previously from a goat with contagious agalactia in northern Jordan. The strain was unusual in that, although it had been identified by molecular methods as Mycoplasma mycoides subsp. mycoides LC/Mycoplasma mycoides subsp. capri, it showed no inhibition of growth by any of the hyperimmune rabbit antisera conventionally used to speciate members of the Mycoplasma mycoides cluster. Animals were infected either intratracheally or by aerosol and placed "in-contact" with other goats. After 2 weeks, those infected intratracheally became febrile, showing a nasal discharge and slight conjunctivitis, followed a week later by respiratory distress and polyarthritis; lesions seen at necropsy included coagulative necrotic pneumonia, fibrinous pleurisy with pleural exudate, and inflammatory exudates, necrosis and fibrosis in the joints. Animals infected by aerosol showed much milder clinical signs, including nasal discharge and occasional swollen joints. In the "in-contact" goats, seroconversion was first seen after 7 weeks, accompanied by coughing and laboured respiration; lesions in this group consisted of fibrinous pneumonia with focal areas of necrosis and abundant pleural exudate.

Spectral hole buming and molecular computing.

The new concept of molecular computing based on spectral hole burning, the interaction of molecular energy levels with an externally applied electric field and the interferometric properties of holography, is presented. Data stored in the form of 2-D arrays are directly combined in parallel without the use of an external processor.