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.

Single-step electrochemical deposition of antimicrobial orthopaedic coatings based on a bioactive glass/chitosan/nano-silver composite system.

Composite orthopaedic coatings with antibacterial capability containing chitosan, Bioglass® particles (9.8µm) and silver nanoparticles (Ag-np) were fabricated using a single-step electrophoretic deposition (EPD) technique, and their structural and preliminary in vitro bactericidal and cellular properties were investigated. Stainless steel 316 was used as a standard metallic orthopaedic substrate. The coatings were compared with EPD coatings of chitosan and chitosan/Bioglass®. The ability of chitosan as both a complexing and stabilizing agent was utilized to form uniformly deposited Ag-np. Due to the presence of Bioglass® particles, the coatings were bioactive in terms of forming carbonated hydroxyapatite in simulated body fluid (SBF). Less than 7wt.% of the incorporated silver was released over the course of 28days in SBF and the possibility of manipulating the release rate by varying the deposition order of coating layers was shown. The low released concentration of Ag ions (<2.5ppm) was efficiently antibacterial against Staphyloccocus aureus up to 10days. Although chitosan and chitosan/Bioglass® coating supported proliferation of MG-63 osteoblast-like cells up to 7days of culture, chitosan/Bioglass®/Ag-np coatings containing 342 µg of Ag-np showed cytotoxic effects. This was attributed to the relatively high concentration of Ag-np incorporated in the coatings.

Copper-releasing, boron-containing bioactive glass-based scaffolds coated with alginate for bone tissue engineering.

The aim of this study was to synthesize and characterize new boron-containing bioactive glass-based scaffolds coated with alginate cross-linked with copper ions. A recently developed bioactive glass powder with nominal composition (wt.%) 65 SiO2, 15 CaO, 18.4 Na2O, 0.1 MgO and 1.5 B2O3 was fabricated as porous scaffolds by the foam replica method. Scaffolds were alginate coated by dipping them in alginate solution. Scanning electron microscopy investigations indicated that the alginate effectively attached on the surface of the three-dimensional scaffolds leading to a homogeneous coating. It was confirmed that the scaffold structure remained amorphous after the sintering process and that the alginate coating improved the scaffold bioactivity and mechanical properties. Copper release studies showed that the alginate-coated scaffolds allowed controlled release of copper ions. The novel copper-releasing composite scaffolds represent promising candidates for bone regeneration.

Hipergranulación periestomal / Peristomal hypergranulation

Las enfermedades cutáneas son comunes en pacientes con estoma. Incluyen desde reacciones irritativas a dermatitis alérgica de contacto, infecciones,alteraciones relacionadas con una enfermedad intestinal y enfermedades cutáneas previas como la psoriasis.Describimos el caso de un paciente conhipergranulación de la colostomía, causada posiblemente por la irritación (AU)

Skin disorders are common in stoma patients. These range from irritant reactions to allergic contact dermatitis, infections, disorders related to boweldisease and pre-existing. A patient with a hypergranulation by colostomy is reported (AU)

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.