Preparation of Scalable Silica‐Coated Iron Oxide Nanoparticles for Nanowarming

Abstract

Cryopreservation technology allows long‐term banking of biological systems. However, a major challenge to cryopreserving organs remains in the rewarming of large volumes (>3 mL), where mechanical stress and ice formation during convective warming cause severe damage. Nanowarming technology presents a promising solution to rewarm organs rapidly and uniformly via inductive heating of magnetic nanoparticles (IONPs) preloaded by perfusion into the organ vasculature. This use requires the IONPs to be produced at scale, heat quickly, be nontoxic, remain stable in cryoprotective agents (CPAs), and be washed out easily after nanowarming. Nanowarming of cells and blood vessels using a mesoporous silica‐coated iron oxide nanoparticle (msIONP) in VS55, a common CPA, has been previously demonstrated. However, production of msIONPs is a lengthy, multistep process and provides only mg Fe per batch. Here, a new microporous silica‐coated iron oxide nanoparticle (sIONP) that can be produced in as little as 1 d while scaling up to 1.4 g Fe per batch is presented. sIONP high heating, biocompatibility, and stability in VS55 is also verified, and the ability to perfusion load and washout sIONPs from a rat kidney as evidenced by advanced imaging and ICP‐OES is demonstrated.

Perfusion, cryopreservation, and nanowarming of whole hearts using colloidally stable magnetic cryopreservation agent solutions

“…Whole-heart perfusion with mCPA assessed using MPI Past studies on nanowarming of biologics with mCPA that have been performed with mCPA have used cells or small sections of tissue submerged in mCPA solution (17,19,20) or have reported nonuniform distribution of SPIONs for organs (liver, kidney, and ovary) and hindlimbs perfused with mCPA (21). We demonstrate that the mCPA reported here can perfuse a whole rat heart and can be removed afterward.…”

Aggregation affects optical properties and photothermal heating of gold nanospheres

“…However, transferrin was not able to stabilize GNS aggregates formed by 30 nm GNS. Polyvinyl pyrrolidone (PVP) has strong affinity to wrap around nanostructures regardless of surface charge, size and material 44 , 45 . Herein, PVP was used to stabilize aggregates formed by 30 nm GNS.…”

Thermal conductivity of cryoprotective agents loaded with nanoparticles, with application to recovery of preserved tissues and organs from cryogenic storage

“…The detailed synthesis method of the sIONP is described by Gao et al [ 12 ]. In short, 1.44g stock IONPs (EMG308, Ferrotec) was coated with 48 g polyvinyl pyrrolidone 10K (PVP, Sigma Aldrich) in 432 mL of MiliQ water by probe sonication.…”

“…Unfortunately, producing msIONP is laborious and costly in gram quantities, which would be needed for nanowarming scale-up to larger tissues and organs. Thus, a simpler and cheaper sol-gel coating with micro-porous silica (sIONP) has been developed, which is operationally equivalent to msIONP for nanowarming These sIONP can be scaled up to > 1400 mg Fe/batch for nanowarming of large tissues and organs [ 12 ].…”