Physical properties and biocompatibility of chitosan/soy blended membranes.

Blends of polysaccharides and proteins are a source for the development of novel materials with interesting and tailorable properties, with potential to be used in a range of biomedical applications. in this work a series of blended membranes composed by chitosan and soy protein isolate was prepared by solvent casting methodology. in addition, cross-linking was performed in situ with glutaraldehyde solutions in the range 5x10(-3)-0.1 M. Furthermore, the influence of the composition and cross-linking on the degradation behaviour, water uptake and cell adhesion was investigated. The obtained results showed that the incorporation of chitosan, associated to network formation by cross linking, promoted a slight decrease of water absorption and a slower degradability of the membranes. Moreover, direct contact biocompatibility studies, with L929 cells, indicate that the cross-linking enhances the capability of the material to support cell growth.

Synthesis and evaluation of novel bioactive composite starch/bioactive glass microparticles.

The aim of the development of composite materials is to combine the most desired properties of two or more materials. In this work, the biodegradable character, good controlled-release properties, and natural origin of starch-based biomaterials are combined with the bioactive and bone-bonding properties of bioactive glass (BG). Novel, bioactive composite starch-BG microparticles were synthesized starting from a blend of starch and polylactic acid (50%/50% wt) with BG 45S5 powder using a simple emulsion method. Morphological and chemical characterization showed that these particles exhibited a spherical morphology with sizes up to 350 microm and that BG 45S5 was incorporated successfully into the composite particles. Upon immersion in a solution simulating body fluids, for periods up to 3 weeks, their bioactive nature was confirmed, as a calcium-phosphate layer resembling biological apatite was formed onto their surface. The short-term cytotoxicity of these materials was also tested by placing 24-h leachables of the materials extracted in culture medium in contact with a fibroblastic cell line (L929) up to 72 h. At this time period, two biochemical tests--MTT and total protein quantification--were performed. The results showed that these materials are not cytotoxic. These results constitute the basis of future encapsulation studies using bone-acting therapeutic agents such as bone morphogenetic proteins or other bone-relevant factors. The particles developed here may be very useful for applications in which controlled release, degradability, and bone-bonding ability are the main requirements.

Child sexual abuse in Matabeleland, Zimbabwe.

The extent, nature, causes and consequences of child sexual abuse in Matabeleland. Zimbabwe, are explored by an intersectoral working group consisting of health, legal and AIDS prevention workers who were struck in the course of their work by the regularity with which they saw sexually abused children infected with HIV and STDs. Methods used in this study are record review, focus group discussions, structured and in-depth interviews. Child sexual abuse cases form between 40-60% of the rape cases brought to the attention of hospitals, police and court and many more are believed to remain unreported. Half of the sexual abuse in children is detected through STDs and some have HIV. The majority of offenders are mature men known to the child. Factors influencing child sexual abuse are male dominance in society, men's professed inability to control sexual desire, and magic beliefs. Victims are traumatized by the abuse itself as well as by subsequent problems in family, health and in court. Since child sexual abuse may endanger the life and well-being of the child, it is a serious problem that requires urgent action.