Preparation and in vitro evaluation of chitosan-coated alginate/calcium complex microparticles loaded with fluorescein-labeled lactoferrin.

An attempt was made to prepare FITC-labeled-lactoferrin (LF-FTC)-loaded microparticles, durable under gastrointestinal conditions, first by the combination of alginate/calcium complexation and emulsification-evaporation and next by treatment with chitosan solution. The obtained microparticles were examined for particle characteristics, in vitro release profiles and physical stability in solutions of pH 1.2 and 6.8. The obtained chitosan-coated alginate/calcium complex microparticles (Ch/Al/Ca-MP) showed almost uniform size of 1-2 microm and a spherical shape with a non-smooth surface. The content and recovery of LF-FTC in Ch/Al/Ca-MP fell as the concentration of chitosan solution used in chitosan coating increased. The release rate of LF-FTC was faster in Ch/Al/Ca-MP prepared with more chitosan at pH 1.2 and 6.8. Ch/Al/Ca-MP coated with 0.25 and 0.5% (w/v) chitosan solution showed good gradual release characteristics in vitro. Furthermore, they were durable at pH 1.2 and 6.8, though swelling and softening of the microparticles occurred at pH 6.8. It is suggested that alginate/calcium complex microparticles coated with 0.25-0.5% (w/v) chitosan solution would be useful for the intestinal delivery of LF.

Anti-interferon-gamma autoantibody in a patient with disseminated Mycobacterium avium complex.

We report the case of a 44-year-old woman with disseminated Mycobacterium avium complex (MAC) infection involving multiple bone lesions despite a normal healthy status until 6 months previously. Because she was suspected to have acquired immunodeficiency, we tested interferon (IFN)-gamma production by peripheral blood mononuclear cells (PBMC) after phytohemagglutinin (PHA) or anti-CD3 stimulation, and found that these cells produced no, or undetectable, levels of IFN-gamma in the presence of the patient's plasma, but produced nearly normal levels of IFN-gamma in the presence of healthy donor plasma. Since the IgG fraction of the patient's plasma was capable of blocking in vitro responses to IFN-gamma, the cause of disseminated MAC infection in this case appeared to be anti-IFN-gamma autoantibodies. To reduce the titer of anti-IFN-gamma autoantibodies, the patient received intravenous immunoglobulin (IVIG). However, titer of autoantibodies changed little compared to that before IVIG administration. According to our literature search, this is only the second case of disseminated MAC infection associated with anti-IFN-gamma autoantibodies in Japan.

Particle characteristics and biodistribution of camptothecin-loaded PLA/(PEG-PPG-PEG) nanoparticles.

Poly(DL-lactic acid) (PLA)/poly(ethylene glycol)-block-poly (propylene glycol)-block-poly(ethylene glycol) copolymer (PEG-PPG-PEG) nanoparticles loaded with camptothecin (CPT), called CPT-NP, were prepared and examined for particle size change and drug release in phosphate-buffered saline, pH 7.4, (PBS), and drug biodistribution profiles in mice bearing sarcoma 180 solid tumor. CPT-NP kept an almost constant mean size and exhibited an initial rapid release of approximately 20%, following by very slow release. As compared with CPT solution, CPT-NP showed higher tissue accumulation and better tumor localization, which were considered essentially associated with the better efficacy of CPT-NP reported in the previous study.