Apoferritin nanocage as streptomycin drug reservoir: Technological optimization of a new drug delivery system.

The aim of this study is to formulate and characterize streptomycin-loaded apoferritin nanoparticles (ApoStrep NPs) for their potential therapeutic use in bacterial resistant infections (i.e. tuberculosis). ApoStrep NPs were prepared by disassembly/reassembly process via pH method and changing apoferritin/drug molar ratio, purified by dialyses process also associated with gel filtration chromatography and characterized in their chemico-physical and technological parameters as yield, size distribution, polidispersivity, morphology, internal structure, zeta potential and loading efficacy. The results showed that spherical reproducible NPs could be obtained by using apoferritin/drug molar ratio lower than 1:25 and purification based on the combination of dialysis and gel filtration chromatography. Photon correlation spectroscopy, Uv-visible detection and electron microscopy showed the maintenance of the native apoferritin chemico-physical properties and structure. When formulated with apoferritin/drug 1:10 and 1:25 molar ratio, ApoStrep NPs showed remarkable encapsulation efficacy (35% and 28%, respectively) along with kinetic profile of drug delivery, approximately 15% at 37 °C in 72h, as evidenced by "in vitro" release experiments.

Importance of microanalysis in understanding mechanism of transformation in active glassy biomaterials.

This work deals with a method to study bioactive glassy materials used for repair of bone defects in order to understand the mechanism of the bioactivity and thus have its in vivo behavior optimized. The study of these materials takes into account their changes in morphology, by means of electron microscopy, after implantation in different animal models and evaluates the mechanism of the bioactivity through semi- and quantitative microanalytical evaluations in order to quantify the phenomenon of glass corrosion and the formation of a chemical bond with bone. Special preparations of glass granules before implantation were prepared to microanalytically study surfaces with different permeabilities.

Beta 1 and beta 3 integrin upregulation in rapidly progressive glomerulonephritis.

The expression and distribution pattern of beta 1 (alpha 1-alpha 6) and alpha v beta 3 integrins and ICAM-1 and VCAM-1 counter receptors were evaluated by an immunohistochemical technique on eight renal samples from patients affected by rapidly progressive glomerulonephritis (RPGN) of different aetiologies. In all cases integrins and counterreceptors displayed similar patterns. On tubular cells of renal cortex, a marked upregulation of alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha v beta 3 integrins and VCAM-1 was observed with as many as 60-90% of tubular cross-sections labelled, while a strong ICAM-1 reactivity was limited to the luminal surface. The same adhesion molecules were also uniformly expressed on crescentic cells. In glomeruli, integrin upregulation occurred only on apparently preserved capillary tufts, i.e. in an early stage of lesion, while collapsed and sclerotic tufts showed a reduced integrin expression. In addition a morphometric study of extracellular matrix (EM) proteins cellular fibronectin and tenascin showed a 9.56 +/- 1.9-fold and 3.35 +/- 0.6-fold increase respectively in these proteins, as compared to normal kidney (P < 0.001). The upregulation of alpha v beta 3 on podocytes might play a role in the adhesion of crescentic cells. An increased production of cytokines, in particular transforming growth factor-beta, might induce augmented deposition of EM proteins and upregulation of beta 1 and beta 3 integrins in RPGN.