Paired comparison of methylene blue- and amotosalen-treated plasma and cryoprecipitate.

BACKGROUND AND OBJECTIVES: Cryoprecipitate is used in the treatment of patients with acquired hypofibrinogenaemia. Studies have not directly compared cryoprecipitate produced following pathogen inactivation (PI) of fresh-frozen plasma (FFP) using different systems. The effects of methylene blue (MB) and amotosalen (AS) PI systems on the quality of FFP and cryoprecipitate were investigated in a paired study. MATERIALS AND METHODS: Seven group A and 7 group O pools of plasma were prepared and split into individual units and rapidly frozen to produce FFP. Units of FFP were thawed and either PI treated with MB or amotosalen, or left untreated (control). Samples of FFP along with the corresponding cryoprecipitate were tested for a range of coagulation factors, thrombin generation (TGT) and rotational thromboelastometry (ROTEM). RESULTS: AS-FFP showed a smaller decrease following treatment for most coagulation factors analysed than MB-FFP, except fibrinogen (antigen) and factor VII, partly due to lower volume losses. There was no significant difference between treatment methods for fibrinogen content of cryoprecipitate with treated units meeting current UK specification, or TGT and ROTEM parameters studied. CONCLUSIONS: MB-cryo contained a significantly higher content of FVIII and lower content of FXIII when compared to AS-cryo, with no difference in fibrinogen activity.

Biodegradable poly(α-hydroxy ester) blended microspheres as suitable carriers for retinal pigment epithelium cell transplantation.

Five blends of poly(L-lactic acid) (PLLA) with poly(D,L-lactic-co-glycolic acid) (PLGA) were used to prepare microcarriers by a solvent evaporation technique. Microcarriers were evaluated as suitable scaffolds to facilitate retinal pigment epithelium (RPE) cell transplantation. The blend ratios were 90:10, 75:25, 50:50, 25:75, 10:90 (PLLA:PLGA). Samples of each microcarrier blend were coated with an extracellular matrix protein. Coated and uncoated microcarriers were seeded with a human RPE cell line. As the lactide unit content increased the size of microcarriers generally became larger and the surface more irregular. Cells remained proliferative and retained phenotype as confirmed by immunocytochemistry. Blends rich in PLLA were superior for maintenance of RPE cell viability. This study demonstrates for the first time the feasibility of using microcarriers as a vehicle for retinal cell transplantation for ocular disease.