@article{roosa_muhamed_young_nellenbach_daniele_ligler_brown_2021, title={Synthesis of sonicated fibrin nanoparticles that modulate fibrin clot polymerization and enhance angiogenic responses}, volume={204}, ISSN={0927-7765}, url={http://dx.doi.org/10.1016/j.colsurfb.2021.111805}, DOI={10.1016/j.colsurfb.2021.111805}, abstractNote={Chronic wounds can occur when the healing process is disrupted and the wound remains in a prolonged inflammatory stage that leads to severe tissue damage and poor healing outcomes. Clinically used treatments, such as high density, FDA-approved fibrin sealants, do not provide an optimal environment for native cell proliferation and subsequent tissue regeneration. Therefore, new treatments outside the confines of these conventional fibrin bulk gel therapies are required. We have previously developed flowable, low-density fibrin nanoparticles that, when coupled to keratinocyte growth factor, promote cell migration and epithelial wound closure in vivo. Here, we report a new high throughput method for generating the fibrin nanoparticles using probe sonication, which is less time intensive than the previously reported microfluidic method, and investigate the ability of the sonicated fibrin nanoparticles (SFBN) to promote clot formation and cell migration in vitro. The SFBNs can form a fibrin gel when combined with fibrinogen in the absence of exogenous thrombin, and the polymerization rate and fiber density in these fibrin clots is tunable based on SFBN concentration. Furthermore, fibrin gels made with SFBNs support cell migration in an in vitro angiogenic sprouting assay, which is relevant for wound healing. In this report, we show that SFBNs may be a promising wound healing therapy that can be easily produced and delivered in a flowable formulation.}, journal={Colloids and Surfaces B: Biointerfaces}, publisher={Elsevier BV}, author={Roosa, Colleen A. and Muhamed, Ismaeel and Young, Ashlyn T. and Nellenbach, Kimberly and Daniele, Michael A. and Ligler, Frances S. and Brown, Ashley C.}, year={2021}, month={Aug}, pages={111805} }
 @article{sproul_nandi_roosa_schreck_brown_2018, title={Biomimetic Microgels with Controllable Deformability Improve Healing Outcomes}, volume={2}, ISSN={2366-7478 2366-7478}, url={http://dx.doi.org/10.1002/adbi.201800042}, DOI={10.1002/adbi.201800042}, abstractNote={Abstract Platelets mediate hemostasis by aggregating and binding to fibrin to promote clotting. Over time, platelets contract the fibrin network to induce clot retraction, which contributes to wound healing outcomes by increasing clot stability and improving blood flow to ischemic tissue. In this study, the development of hollow platelet‐like particles (PLPs) that mimic the native platelet function of clot retraction in a controlled manner is described and it is demonstrated that clot retraction‐inducing PLPs promote healing in vivo. PLPs are created by coupling fibrin‐binding antibodies to CoreShell (CS) or hollow N ‐isopropylacrylamide (NIPAm) microgels with varying degrees of shell crosslinking. It is demonstrated that hollow microgels with loosely crosslinked shells display a high degree of deformability and mimic activated platelet morphology, while intact CS microgels and hollow microgels with increased crosslinking in the shell do not. When coupled to a fibrin‐binding antibody to create PLPs, hollow particles with low degrees of shell crosslinking cause fibrin clot collapse in vitro, recapitulating the clot retraction function of platelets, while other particle types do not. Furthermore, hollow PLPs with low degrees of shell crosslinking improve some wound healing outcomes in vivo.}, number={10}, journal={Advanced Biosystems}, publisher={Wiley}, author={Sproul, Erin P. and Nandi, Seema and Roosa, Colleen and Schreck, Luisa and Brown, Ashley C.}, year={2018}, month={Aug} }