Nanowarming technology for effective rewarming of vitrified tissues and organs

Period of Performance: 04/01/2015 - 09/30/2015


Phase 1 SBIR

Recipient Firm

Tissue Testing Technologies, LLC
Principal Investigator


DESCRIPTION (provided by applicant): There are huge markets for research, diagnostic and clinical applications of naturally occurring and engineered cells, tissues and organs. Strategic assessment of the field has identified the need for better preservation methods because freezing methods of cryopreservation have been shown to damage tissues and organs due to ice formation. Vitrification, sub-zero storage below the glass transition temperature in a glassy rather than a crystalline frozen phase, is a form of cryopreservation that avoids ice formation. It is an important enabling approach for cellular and regenerative medicine, offering the ability to store and transport cells, tissues and organs for a great variety of biomedical uses. Unfortunately, practical application of vitrification has been limited to smaller systems such as cells and thin tissues due to diffusive (heat and mass transfer) and phase change limitations that preclude use in organs and larger tissues. To circumvent this problem we propose using radiofrequency excited magnetic nanoparticles around and within biomaterials. This approach has the potential to dramatically improve vitrification through faster and more uniform thawing rates, thereby reducing or eliminating devitrification and thermal stress associated cracking to improve viability and structural integrity upon rewarming. In addition more rapid warming rates will also permit use of lower concentrations of cryoprotectants that will reduce the risks of cytotoxicity. Preliminary experiments have demonstrated that this innovative rewarming technique can increase heating rates by at least an order of magnitude over conventional boundary heating and that it does not depend on sample size. We propose using animal-derived blood vessel tissue models for development of a new approach for rapidly and uniformly heating vitrified biospecimens in two specific aims. The magnetic nanoparticles will be surrounding the vessel and within the vessel lumen. In Aim 1 the magnetic nanoparticles will be coated with biocompatible mesoporous silica and the effects of coated magnetic nanoparticle concentration and radiofrequency on a thin walled (<100?m) animal artery model will be assessed. In Aim 2 finite element modeling of heat transfer will be performed followed by experimental evaluation of samples from 3-100mL, total volume, containing animal blood vessels varying in wall thickness (<100 - >1,000 ?m) in order to determine the impact of variable non-uniform magnetic nanoparticle biodistribution. In both aims function of cells and tissues will be demonstrated using established viability assays and effective vitrification will be evaluated using computed tomography and cryosubstitution methods to detect ice formation. These studies will combine to test the feasibility of our working hypothesis that radiofrequency excited biocompatible magnetic nanoparticles can be utilized to rewarm large volume samples without devitrification, associated ice damage, or cryoprotectant toxicity. Provided that these studies employing vascular tissue models demonstrate feasibility of our technology, we will be assessed vitrification and magnetic rewarming of organs in a future Phase II SBIR proposal.