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Abstract Devising an approach to deterministically position organisms can impact various fields such as bioimaging, cybernetics, cryopreservation, and organism‐integrated devices. This requires continuously assessing the locations of randomly distributed organisms to collect and transfer them to target spaces without harm. Here, an aspiration‐assisted adaptive printing system is developed that tracks, harvests, and relocates living and moving organisms on target spaces via a pick‐and‐place mechanism that continuously adapts to updated visual and spatial information about the organisms and target spaces. These adaptive printing strategies successfully positioned a single static organism, multiple organisms in droplets, and a single moving organism on target spaces. Their capabilities are exemplified by printing vitrification‐ready organisms in cryoprotectant droplets, sorting live organisms from dead ones, positioning organisms on curved surfaces, organizing organism‐powered displays, and integrating organisms with materials and devices in customizable shapes. These printing strategies can ultimately lead to autonomous biomanufacturing methods to evaluate and assemble organisms for a variety of single and multi‐organism‐based applications. 

Abstract Focal therapies such as hyperthermia have been successfully used to treat solid localized tumors; however, they are not easily applied to cancers that may present in a disseminated form such as ovarian cancer. To address this need, iron oxide (IO) particles were incorporated into microporous poly(caprolactone) scaffolds previously shown to recruit disseminating cancer cells. Under an alternating magnetic field, IO‐loaded scaffolds exhibited heating and killed ID8 ovarian cancer cells in vitro. After implantation in the intraperitoneal cavity of mice, IO‐loaded scaffolds became infiltrated with tissue after 6–7 weeks, and infiltrated cells were successfully treated ex vivo. Finally, IO‐loaded scaffolds noninvasively killed infiltrated cells in vivo as evidenced by decreases in number of nuclei. These studies demonstrate the promising use of IO‐loaded scaffolds as a tool for noninvasive hyperthermia, which could be an innovative modality for treatment of disseminated cancers. 

Abstract Coral reefs are threatened by anthropogenic climate change, which causes ocean acidification and warming that can result in coral death and the loss of genetic diversity on reefs around the world. Global efforts to secure the genetics of threatened populations using cryopreservation and biobanking are underway but are limited to coral sperm and larvae, available only during brief annual spawning events. Methods to cryopreserve adult coral tissues to enable biobanking activities year‐round are urgently needed, but are challenging due to the presence of a calcium carbonate skeleton and algal symbionts within the tissues, and chill sensitivity. In this study, vitrification and laser nanowarming permitted successful recovery of adult coral tissues in a novel sample type, the single‐polyp microfragment. Fluorescence and confocal microscopy shows clearly defined green fluorescent protein auto‐fluorescence around the polyp mouth post‐warming, with an overall survival rate of 39.7 ± 7.4% at 24 h post‐warming and 23.3 ± 9.7% at 1 month, but relatively few algal symbionts are present in the tissues, indicating poor survival of these cells. These proof‐of‐concept results provide a basis for continued research and development of a field‐ready protocol for cryopreservation of adult coral tissues, which will be essential to prevent extinctions and support reef restoration. 

Abstract Vitrification can dramatically increase the storage of viable biomaterials in the cryogenic state for years. Unfortunately, vitrified systems ≥3 mL like large tissues and organs, cannot currently be rewarmed sufficiently rapidly or uniformly by convective approaches to avoid ice crystallization or cracking failures. A new volumetric rewarming technology entitled “nanowarming” addresses this problem by using radiofrequency excited iron oxide nanoparticles to rewarm vitrified systems rapidly and uniformly. Here, for the first time, successful recovery of a rat kidney from the vitrified state using nanowarming, is shown. First, kidneys are perfused via the renal artery with a cryoprotective cocktail (CPA) and silica‐coated iron oxide nanoparticles (sIONPs). After cooling at −40 °C min⁻¹in a controlled rate freezer, microcomputed tomography (µCT) imaging is used to verify the distribution of the sIONPs and the vitrified state of the kidneys. By applying a radiofrequency field to excite the distributed sIONPs, the vitrified kidneys are nanowarmed at a mean rate of 63.7 °C min⁻¹. Experiments and modeling show the avoidance of both ice crystallization and cracking during these processes. Histology and confocal imaging show that nanowarmed kidneys are dramatically better than convective rewarming controls. This work suggests that kidney nanowarming holds tremendous promise for transplantation. 

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. 

Abstract To extend the preservation of donor hearts beyond the current 4–6 h, this paper explores heart cryopreservation by vitrification—cryogenic storage in a glass‐like state. While organ vitrification is made possible by using cryoprotective agents (CPA) that inhibit ice during cooling, failure occurs during convective rewarming due to slow and non‐uniform rewarming which causes ice crystallization and/or cracking. Here an alternative, “nanowarming”, which uses silica‐coated iron oxide nanoparticles (sIONPs) perfusion loaded through the vasculature is explored, that allows a radiofrequency coil to rewarm the organ quickly and uniformly to avoid convective failures. Nanowarming has been applied to cells and tissues, and a proof of principle study suggests it is possible in the heart, but proper physical and biological characterization especially in organs is still lacking. Here, using a rat heart model, controlled machine perfusion loading and unloading of CPA and sIONPs, cooling to a vitrified state, and fast and uniform nanowarming without crystallization or cracking is demonstrated. Further, nanowarmed hearts maintain histologic appearance and endothelial integrity superior to convective rewarming and indistinguishable from CPA load/unload control hearts while showing some promising organ‐level (electrical) functional activity. This work demonstrates physically successful heart vitrification and nanowarming and that biological outcomes can be expected to improve by reducing or eliminating CPA toxicity during loading and unloading.