Novel nanocomposite biomaterials with controlled copper/calcium release capability for bone tissue engineering multifunctional scaffolds.

This work aimed to develop novel composite biomaterials for bone tissue engineering (BTE) made of bioactive glass nanoparticles (Nbg) and alginate cross-linked with Cu(2+) or Ca(2+) (AlgNbgCu, AlgNbgCa, respectively). Two-dimensional scaffolds were prepared and the nanocomposite biomaterials were characterized in terms of morphology, mechanical strength, bioactivity, biodegradability, swelling capacity, release profile of the cross-linking cations and angiogenic properties. It was found that both Cu(2+) and Ca(2+) are released in a controlled and sustained manner with no burst release observed. Finally, in vitro results indicated that the bioactive ions released from both nanocomposite biomaterials were able to stimulate the differentiation of rat bone marrow-derived mesenchymal stem cells towards the osteogenic lineage. In addition, the typical endothelial cell property of forming tubes in Matrigel was observed for human umbilical vein endothelial cells when in contact with the novel biomaterials, particularly AlgNbgCu, which indicates their angiogenic properties. Hence, novel nanocomposite biomaterials made of Nbg and alginate cross-linked with Cu(2+) or Ca(2+) were developed with potential applications for preparation of multifunctional scaffolds for BTE.

Selective and partial IgA deficiency in an adolescent male with bronchiectasis.

Selective IgA deficiency is the most common primary immunodeficiency. Two types of selective IgA deficiency may be distinguished: the complete form, with IgA level less than 5 mg/dl, and the partial IgA deficiency, with level greater than 5 mg/dl but less than 2 standard deviations below the age-adjusted mean level; 50% of the cases belong to the partial type and half of them may be considered as transient clinical form. Patterns of this condition, are very unsteady: while some patients remain without any symptoms, others present recurrent respiratory and gastrointestinal tract infections. Though respiratory tract infections are the most frequent diseases, and in very few patients are associated bronchiectasis. A twelve-year-old patient with permanent partial IgA deficiency was treated for bronchiectasis in our pneumology and allergy pediatric center. The other serum immunoglobulins, IgG subclass, lymphocytes sub-populations, cell with expression of DR markers and proliferative response to PHA of peripheral blood lymphocytes, were normal. The alpha-1-antitrypsin, Mantoux test (negative), sweat chloride concentration and ciliated nasal epithelium were also normal. Pneumonia, bronchiectasis and meningitis are found in the complete IgA deficiency. The greater part of studies confirm that this severe, chronic and/or recurrent lower respiratory tract diseases are scarcely found in children with partial selective IgA deficiency, although our case states that it can be found. We think that in every patient with bronchiectasis the selective IgA deficiency complete or partial, has to be considered as an isolated etiologic factor.