Silk4B’s silk-based 3D bone marrow models allow differentiation into mature functional platelets that resemble and behave as peripheral blood platelets found in the human body.

Platelets can be differentiated from patient derived primary HSPCs, Megakaryocytes, iPSC-derived progenitors, or cell lines. Works with mouse cells, too. Differentiation process follows the in vivo path of early progenitors, late progenitors, and megakaryocytes. 

The non-thrombogenic properties of our 3D bone marrow models means platelets do not aggregate, can be isolated and used in downstream assays. Platelet collection is easy from both silk hydrogel and silk scaffold models. In the scaffold model, media can be perfused through the model mimicking blood flow, and platelets released during differentiation are carried into the perfusate mirroring platelet release into the bloodstream in vivo. This allows for their easy collection.

Due to in vivo mimicking properties of our silk-based 3D bone marrow niches, platelet differentiation is highly effective, with a considerably higher percentage of MK-forming platelets. This results in ~6x higher yield of platelets than 2D culture or other conventional bioinks when starting from the same amount of progenitor cells. 

The 3D architecture of Silk4Bs bone marrow and in vivo mimicking conditions for cell differentiation allow for less media and reagents to be needed for differentiation from the same progenitor cell number compared to 2D liquid culture. Specifically, ~80% lower reagent costs per progenitor cells used. For experiments where the final platelets are necessary, given that Silk4B’s 3D bone marrow has 6x higher platelet yield per progenitor cells, the reagent cost reduction is even higher at ~95% per platelet amount generated. 

The 3D architecture of Silk4Bs bone marrow also provides a physical environment protecting the cells, which significantly simplifies the media change steps during differentiation compared to 2D liquid culture. In 2D liquid culture several steps have to be undertaken for media change during differentiation process (cell collection, centrifugation, media replacement). In our 3D bone marrow models a quick media change is sufficient as cells remain within the silk-based bone marrow matrix during the process. As a result, an entire platelet differentiation protocol will take 3h of personnel time with 2D liquid culture, and only 0.9h using our 3D bone marrow models. This is ~70% personnel time and cost savings.