title: Colloidal Properties of Nanoerythrosomes Derived from Bovine Red Blood Cells.
abstract: Liposomes are nanoscale containers that are typically synthesized from lipids using a high-shear process such as extrusion or sonication. While liposomes are extensively used in drug delivery, they do suffer from certain problems including limited colloidal stability and short circulation times in the body. As an alternative to liposomes, we explore a class of container structures derived from erythrocytes (red blood cells). The procedure involves emptying the inner contents of these cells (specifically hemoglobin) and resuspending the empty structures in buffer, followed by sonication. The resulting structures are termed nanoerythrosomes (NERs), i.e., they are membrane-covered nanoscale containers, much like liposomes. Cryo-transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS) are employed for the first time to study these NERs. The results reveal that the NERs are discrete spheres (∼110 nm diameter) with a unilamellar membrane of thickness ∼4.5 nm. Remarkably, the biconcave disc-like shape of erythrocytes is also exhibited by the NERs under hypertonic conditions. Moreover, unlike typical liposomes, NERs show excellent colloidal stability in both buffer as well as in serum at room temperature, and are also able to withstand freeze-thaw cycling. We have explored the potential for using NERs as colloidal vehicles for targeted delivery. Much like conventional liposomes, NER membranes can be decorated with fluorescent or other markers, solutes can be encapsulated in the cores of the NERs, and NERs can be targeted to specifically bind to mammalian cells. Our study shows that NERs are a promising and versatile class of nanostructures. NERs that are harvested from a patient's own blood and reconfigured for nanomedicine can potentially offer several benefits including biocompatibility, minimization of immune response, and extended circulation time in the body.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States.|Department of Radiation Oncology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States.
authors.forename: Yuan-Chia
authors.initials: YC
authors.lastname: Kuo
authors.affiliation: Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States.|Department of Biochemical Science and Technology, National Taiwan University , Taipei 10617, Taiwan.
authors.forename: Hsuan-Chen
authors.initials: HC
authors.lastname: Wu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Dao
authors.initials: D
authors.lastname: Hoang
authors.affiliation: Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: William E
authors.initials: WE
authors.lastname: Bentley
authors.affiliation: Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States.|Department of Radiation Oncology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States.
authors.forename: Warren D
authors.initials: WD
authors.lastname: D'Souza
authors.affiliation: Fischell Department of Bioengineering, University of Maryland , College Park, Maryland 20742, United States.|Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Srinivasa R
authors.initials: SR
authors.lastname: Raghavan
mesh_terms: D000818:Animals; D002417:Cattle; D003102:Colloids / Q000737:chemistry*; D020285:Cryoelectron Microscopy; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D004912:Erythrocytes / Q000737:chemistry* / Q000648:ultrastructure; D008081:Liposomes / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D003102:Colloids; D004337:Drug Carriers; D008081:Liposomes