In vitro comparison between gamma-irradiated cryopreserved and Day 7 liquid-stored buffy coat-derived platelet components.

BACKGROUND: Cryopreserved platelet (PLT) components stored at -80°C in 5% to 6% dimethyl sulfoxide (DMSO) demonstrate enhanced hemostatic activity. Alterations in PLT surface glycoprotein expression and release of procoagulant microparticles during the freeze/thaw cycle result in PLT activation. Nothing is known of the effect of gamma irradiation on the in vitro quality of reconstituted cryopreserved PLTs. STUDY DESIGN AND METHODS: Gamma-irradiated (25-50 Gy) buffy coat-derived PLT components were either stored at room temperature for 7 days (the current expiry in New Zealand) or cryopreserved at -80°C using 5% to 6% DMSO. Cryopreserved PLTs were thawed at 37°C and reconstituted in ABO-identical plasma or PAS-E and compared to Day 7 gamma-irradiated liquid-stored PLTs. In vitro assays were performed to assess glycoprotein expression, PLT functionality and soluble cytokine release. RESULTS: Cryopreserved PLTs after thawing and reconstitution in ABO-matched plasma or PAS-E displayed differing recoveries (82.7 and 75.9%, respectively). Key expression levels of glycoproteins GPIbα (CD42b) and GPIIb (CD41a) were reduced. Cryopreserved PLTs retained the ability to form an effective functional clot, while showing accelerated initiation of clot formation (R-time) compared to Day 7 gamma-irradiated liquid-stored PLTs. CONCLUSION: Gamma-irradiated buffy coat-derived liquid-stored and cryopreserved PLTs have distinctly differing phenotypes. Cryopreserved PLTs reconstituted in ABO plasma have enhanced clot strength driven by coagulation factors and fibrinogen levels not present in PAS-E. Irradiated cryopreserved PLTs maintain a similar in vitro quality profile and hemostatic behavior to previously published, nonirradiated cryopreserved PLTs.

Characteristics of Platelet Lysate Compared to Autologous and Allogeneic Serum Eye Drops.

Purpose: Platelet lysate produced from platelet apheresis components has been proposed as an alternative to serum eye drops in the treatment of ocular surface disease. This study compared the effects of platelet lysate and serum on growth factor, cytokine and nanoparticle concentrations, and corneal epithelial cell proliferation. Methods: The concentration of growth factors, cytokines, and nanoparticles in platelet lysates manufactured from either fresh or expired platelet apheresis concentrations collected with Trima or Haemonetics technology was characterized and compared with those of allogeneic, autologous, and fetal calf serum. The ability to promote corneal epithelial cell proliferation and wound healing was tested in vitro. Results: Platelet lysate enriched the amount of transforming growth factor ß1, platelet-derived growth factor -AB and -BB, fibroblast growth factor, and epidermal growth factor compared with the two sera groups. The concentrations of insulin-like growth factor 1, hepatocyte growth factor, and fibronectin were significantly lower than in sera. There were no differences in nanoparticle concentrations. There was no significant difference in corneal epithelial cell proliferation. Platelet lysates were comparable to fetal calf serum in accelerating corneal epithelial wound healing in vitro. Conclusions: Fresh and expired platelet lysates from the Trima and Haemonetics systems had higher growth factor concentrations than sera. The ability of platelet lysates to promote corneal epithelial cell proliferation and wound healing was equivalent to sera. Translational Relevance: Platelet lysates may serve as an efficient and reliable source of human growth factors for the treatment of ocular surface diseases.

(±)-2'-Phenyl-cyclo-hexa-nespiro-4'-(aze-pano[1,2-b]isoxazolidine).

In the crystal structure of the racemic title isoxazolidine, C(19)H(27)NO, the relative stereochemistry between the phenyl group and the bridgehead H atom is shown to be syn. There are two mol-ecules in the asymmetric unit, one of which is the 7R*,13R* enanti-omer, and one of which is the 7S*,13S* enanti-omer. These enanti-omers adopt different orientations of the phenyl ring with respect to the isoxazolidine ring, with C-C-C-C torsion angles of 63.6 (4) and 86.8 (4)°, respectively. In both enanti-omers, the six-membered ring adopts a chair conformation, while the seven-membered ring adopts a twist-chair conformation.