An object of the present invention is to provide a method of promoting polyploidization of megakaryocytes and thereby producing highly polyploidized megakaryocytes, a method of efficiently producing platelets from polyploidized megakaryocytes, and the like. The present invention provides a method of producing polyploidized megakaryocytes comprising a step of forcing expression of an apoptosis suppressor gene in megakaryocytes before polyploidization and culturing the resulting cells.

Disclosed herein are methods of producing platelets comprising a modified receptor, therapeutic agents, peptides, and/or bioactive molecules. The cells produced by the methods disclosed herein can be used to treat, manage, prevent and diagnosis, for example, lysosomal storage diseases, diabetes and cancer. The cells produced by the methods disclosed herein can be engineered to comprise receptors capable of activating platelets to trigger the release of enzymes, biomolecules or therapeutic agents upon binding to specific drugs and/or binding to tissue specific peptides.

The invention relates to a method of producing CD34+CD4.sup.dim megakaryocyte (MK) progenitor cells, and substantially pure cell population of megakaryocyte precursor cells obtained by said method. The invention also relates to a method of producing proplatelet-bearing MKs and/or platelets using the CD34+CD4.sup.dim cells.

The present invention provides, among other things, methods for producing platelets including the steps of providing a silk membrane about 2 μm and 100 μm thick, inclusive, contacting the silk membrane with a porogen to form a porous silk membrane comprising at least one silk wall defining a lumen, associating the porous silk membrane with stromal derived factor-1? and at least one functionalizing agent, forming a three dimensional silk matrix comprising interconnected pores wherein the pores have a diameter of between about 5 and 500 μm, inclusive, wherein the silk matrix is formed around at least a portion of the porous silk membrane, introducing a plurality of megakaryocytes to the silk matrix such that the megakaryocytes are located at least partially within the porous silk matrix, and stimulating the plurality of megakaryocytes to produce platelets. Also provided are various new compositions and methods of making those compositions.

Acoustophoretic devices for separating particles from a non-flowing host fluid are disclosed. The devices include a substantially acoustically transparent container and a separation unit, with the container being placed within the separation unit. An ultrasonic transducer in the separation unit creates a planar or multi-dimensional acoustic standing wave within the container, trapping particles disposed within the non-flowing fluid and causing them to coalesce or agglomerate, then separate due to buoyancy or gravity forces.

Methods for production of platelets from pluripotent stem cells, such as human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) are provided. These methods may be performed without forming embryoid bodies or clusters of pluripotent stem cells, and may be performed without the use of stromal inducer cells. Additionally, the yield and/or purity can be greater than has been reported for prior methods of producing platelets from pluripotent stem cells. Also provided are compositions and pharmaceutical preparations comprising platelets, preferably produced from pluripotent stem cells.

The present invention provides engineered platelets with chimeric platelet receptors (CPR) with a desired target specificity. Additionally, the engineered platelets may comprise cargo which may be released upon activation of the platelet. Additionally, the platelets may be generated in vitro from megakaryocytes engineered to generate non-thrombogenic platelets.

Provided herein, in one aspect, is hematopoietic lineage cells such as natural killer cells generated in vitro from human pluripotent stem cells (hPSCs) that can be used as a cell source for therapeutics. Methods and compositions for making and using the same are also provided.

A pure platelet-rich plasma (P-PRP) composition as an alternative to conventional antibiotic treatment of subclinical mastitis caused by Gram-positive bacteria in bovine including five live platelets and leukocytes, an anticoagulant, and an activating substance.

An in vitro process for producing megakaryocytes, and optionally platelets from the megakaryocytes, including the steps of cultivating stem cells, e.g. induced pluripotent stem cells, to generate aggregated pluripotent stem cells, preferably cultivating the aggregates in suspension in medium, inducing differentiation in these aggregates, and isolating megakaryocytes from the culture medium.