The main actors involved in parasitization of Heliothis virescens larva

At the moment of parasitization by another insect, the host Heliothis larva is able to defend itself by the activation of humoral and cellular defenses characterized by unusual reactions of hemocytes in response to external stimuli. Here, we have combined light and electron microscopy, staining reactions, and immunocytochemical characterization to analyze the activation and deactivation of one of the most important immune responses involved in invertebrates defense, i.e., melanin production and deposition. The insect host/parasitoid system is a good model to study these events. The activated granulocytes of the host insect are a major repository of amyloid fibrils forming a lattice in the cell. Subsequently, the exocytosed amyloid lattice constitutes the template for melanin deposition in the hemocel. Furthermore, cross-talk between immune and neuroendocrine systems mediated by hormones, cytokines, and neuromodulators with the activation of stress-sensoring circuits to produce and release molecules such as adrenocorticotropin hormone, alpha melanocyte-stimulating hormone, and neutral endopeptidase occurs. Thus, parasitization promotes massive morphological and physiological modifications in the host insect hemocytes and mimics general stress conditions in which phenomena such as amyloid fibril formation, melanin polymerization, pro-inflammatory cytokine production, and activation of the adrenocorticotropin hormone system occur. These events observed in invertebrates are also reported in the literature for vertebrates, suggesting that this network of mechanisms and responses is maintained throughout evolution

Study of novel rosin-based biomaterials for pharmaceutical coating

The film forming and coating properties of Glycerol ester of maleic rosin (GMR) and Pentaerythritol ester of maleic rosin (PMR) were investigated. The 2 rosin-based biomaterials were initially characterized in terms of their physicochemical properties, molecular weight (Mw), and glass transition temperature (Tg). Films were produced by solvent evaporation technique on a mercury substrate. Dibutyl sebacate plasticized and nonplasticized films were characterized by mechanical (tensile zzzz strength, percentage elongation, and Young's modulus), water vapor transmission (WVT), and moisture absorption parameters. Plasticization was found to increase film elongation and decrease the Young's modulus, making the films more flexible and thereby reducing the brittleness. Poor rates of WVT and percentage moisture absorption were demonstrated by various film formulations. Diclofenac sodium-layered pellets coated with GMR and PMR film formulations showed sustained drug release for up to 10 hours. The release rate was influenced by the extent of plasticization and coating level. The results obtained in the study demonstrate the utility of novel rosin-based biomaterials for pharmaceutical coating and sustained-release drug delivery systems