Vindico NanoBioTechnology Inc. (Vindico) is developing a hemoglobin-based cellular oxygen therapeutic (blood substitute), NanoHeme, based on its proprietary nanoparticle-based delivery platform known as polymersome. Polymersomes are synthetic polymer vesicles that are formed in nanometric dimensions which can efficiently encapsulate oxygen-carrying proteins such as hemoglobin (Hb). The lead NanoHeme formulation comprises of a diblock copolymer comprising hydrophilic polyethylene oxide (PEO) and hydrophobic polycaprolactone (PCL). NanoHeme demonstrates all the characteristics of ideal oxygen therapeutic, such as tunable oxygen binding capacity, uniform and small size, viscosity and oncotic pressure characteristics similar to human blood as well as ease of mass production and storage. Encapsulation of Hb inside polymersome core protects surrounding tissues and blood components from direct contact with Hb and it also allows for the use of less expensive animal Hb. It also allows for manipulation of physicochemical properties of NanoHeme to improve its intravascular persistence and colloidal state. Additionally, NanoHeme exhibits several advantages over other cellular Hb-based oxygen carriers under development. PEO provides NanoHeme improved in vitro chemical stability, augmented in vivo bioavailablity and prolonged blood circulation half-lives over liposome-based oxygen therapeutics. PCL, a well-known implantable biomaterial, forms the vesicle membrane, and facilitates complete and safe in vivo degradation of resulting product by hydrolysis of its ester linkages. Polymersome membrane is significantly thicker than liposome which offers NanoHeme improved mechanical properties. Polymersomes are stable for several months in situ, and for several days in blood plasma without any changes in size and morphology. Thus, NanoHeme will build on the advantages while circumventing the limitations seen with synthetic oxygen therapeutics. The use of NanoHeme will meet a major unmet medical need by helping to alleviate the current US and worldwide blood shortage and by decreasing our dependence on human RBC transfusions. It will result in tremendous cost saving for transfusion centers on account of reduced reagent and labor costs and decreased costs of patient care on account of problems with RBC transfusions. It will have a market in excess of $1 billion per year in the United States alone resulting in enormous job creation and economic stimulus. Vindico's academic collaborators have demonstrated proof-of-principle encapsulation of hemoglobin in biodegradable polymersomes. In this work, we will optimize the construction of polymersome encapsulated Hb dispersions by exploring range of copolymers from the PEO-b-PCL family as composite building blocks, different hemoglobin sources and different production conditions to create an array of PEH dispersions. These dispersions will be rigorously characterized for particle size and morphology, hemoglobin encapsulation efficiency and methamoglobin (metHb) level, We will also characterize the functional properties of PEH dispersions such as their binding characteristics with oxygen and nitric oxide and their stability under physiological conditions over an extended period of time. PEH dispersions that meet our feasibility criteria will be advanced to Phase II to determine their pharmacokinetics, biodistribution, toxicology and tissue oxygenation in small-animal models. By the end of Phase II, we anticipate having collected sufficient data to determine an appropriate regulatory path to the clinic, and will have presented this plan to the FDA. By the end of the entire project, Vindico will have developed world's first effective, safe and reliable synthetic oxygen carrier for human and veterinary use.
Project Narrative This research will have a major impact on public health by providing a new synthetic oxygen therapeutic (blood substitute) that can be administered to patients. This product will overcome all the limitations associated with red blood cell transfusion and synthetic oxygen therapeutics under development. The use of this product will reduce the significant blood shortage in US and world. The end result will be an improved standard of patient care and less patient mortality. Significant additional advantages will be a tremendous cost savings to the health care system in reduced operating costs, as well as enormous job creation and economic stimulus.
|Tao, Zhimin; Ghoroghchian, P Peter (2014) Microparticle, nanoparticle, and stem cell-based oxygen carriers as advanced blood substitutes. Trends Biotechnol 32:466-73|