Polymerization-Induced Phase Separation Formation of Structured Hydrogel Particles via Microfluidics for Scar Therapeutics.

Excessive scar formation can form disabling contractures that result in a debilitating psychological outcome. Sustainable hydrophobic corticosteroid release in vivo is essential to regulate the wound healing process. Functional hydrogel particles are widely applied for sustainable release. However, due to the limited aqueous solubility of hydrophobic compounds, most of the corticosteroid is released from the hydrogels within seconds, causing undesirable scar formation and recurrence. In this study, a novel polymerization-induced phase separation is investigated to form well-defined polyethylene glycol diacrylate (PEGDA) core/alginate shell structured hydrogel particles using microfluidics without toxic organic solvents. Based on their wettability preference, hydrophobic corticosteroid-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles are compartmentalized in the PEGDA core during polymerization to control the corticosteroid release. The distribution of the PLGA nanoparticles is precisely regulated by the phase separation boundary and characterized using a fluorescent dye. The thickness of the shell and partition coefficients are determined using the UV intensity and irradiation period. Upon encapsulation of the PLGA nanoparticles within the poly(PEGDA) core, a long-term corticosteroid treatment is developed and effective scar therapeutic outcomes are evaluated using both in vitro and in vivo models.

Comparison of efficiency of complements from various species for T-cell depletion from Cercopithecus aethiops bone marrow with Campath-1 MoAb in vitro.

Mature T-cells were removed from Cercopithecus aethiops monkey bone marrow with Campath-1 MoAb plus complement from various species (man, rabbit and monkey). The T-cell depletion was more effective and stable with rabbit or human complement than with autologous (monkey) complement. The most complete and effective lytic function to T-cells was found in the case of rabbit complement. Rabbit complement can be used successfully to deplete bone marrow T-cells of C. aethiops with Campath-1 in vitro.

Cercopithecus aethiops monkey as a reliable model for in vitro study of T cell depletion of bone marrow with Campath-1 plus complement.

T-lymphocyte markers of peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) of C. aethiops monkeys were studied by using anti-human monoclonal antibodies. The results show that C. aethiops T lymphocytes express surface markers which react specifically with anti-human MoAbs including CD3, CD4, CD8, CD2. However, very few CD3-positive cells were found, in contrast to the abundance in CD8+ cells. There is a high conservation of receptors forming E rosettes with AET-treated SRBCs, and antigens reacting with the anti-human T and B cell monoclonal antibody (Campath-1). The present findings indicate that C. aethiops can be used as a new experimental model for studies on T-cell depletion from bone marrow with Campath-1 MoAb + rabbit C.

T-cell depletion of Cercopithecus aethiops monkey bone marrow with Campath-1 monoclonal antibody and complement.

The effectiveness of anti-human monoclonal antibody (Campath 1) plus complement (C') in removal of T-cells from Cercopithecus aethiops monkey bone marrow was studied. Recovery of haemopoietic progenitor cells (CFU-GM) was also investigated in vitro after treatment with Campath-1 plus C'. The results showed that the cell-yield was 37.2 +/- 9.8 after Ficoll separation and 44.2 +/- 13.2% after Campath-1 + + C' treatment. The CFU-GM yields referred to the original total CFU-GM were 88.9 +/- 24.0 and 40.0 +/- 14.3%, respectively. After Campath-1 treatment, CFU-GM per 10(5) bone marrow cells was 269.3 as compared to the pretreatment value of 213.0. In the T-cell-depleted bone marrow suspensions mature T lymphocytes could not be detected. Following cryopreservation more than 70% of CFU-GM could be recovered in T-cell depleted bone marrow suspensions kept in frozen state for two months. Cercopithecus aethiops monkeys can be used as a model to study T-cell depletion of bone marrow with Campath-1 plus C' for studying allogeneic bone marrow transplantation.

Some changes in immunity and blood in relation to clinical states of dengue hemorrhagic fever patients in Vietnam.

The role of immunological factors in the pathogenesis of Dengue Hemorrhagic Fever (DHF), particularly Dengue Shock Syndrome (DSS) was studied. The complement activity, circulating immune complex (IC), histamine level, platelets and leucocytes were determined in the blood of 30 patients and 43 healthy persons. The results showed a significant decrease in complement activity, platelet and neutrophil counts, an increase of histamine level (P less than 0.001), and the presence of circulating IC in 80 per cent of our patients. Furthermore, a marked correlation was found between the changes of the above parameters and the clinical stages of the disease. These parameters can be used in the prognostics of the pre-shock and shock syndrome of DHF.

Human fetal liver as a valuable source of haemopoietic stem cells for allogeneic bone marrow transplantation.

The CFU-GM and T cell contents of human fetal livers were studied at various times between 6-14 weeks of gestation. The number of CFU-GM increased parallel to gestational age, especially after week 10. Cells bearing mature T cell markers, however, were found only in one case out of 35 fetal liver samples. Cryopreservation of fetal liver cells hardly affected the viability and proliferative capacity of CFU-GM in the sample. According to these findings fetal liver is, at least up to the 14th gestational week, practically free of mature T cells but it does contain a considerable amount of CFU-GM (an accepted indicator of pluripotent stem cell content), consequently fetal liver can be considered as a valuable source of haemopoietic stem cells for allogeneic bone marrow transplantation for children.