Boris Rubinsky

• PhD, MIT, 1981
• Professor (Full) at University of California, Berkeley

Oil‐in‐water emulsions, such as dairy cream, can destabilise into an oily and an aqueous phase after freezing and thawing due to ice crystal formation. This work examined the freeze–thaw stability of dairy cream after isochoric cooling at subfreezing temperatures and conventional freezing (CF). Samples were processed under isochoric cooling conditi...

Background Focal ablation techniques are integral in the surgical intervention of diseased tissue, where it is necessary to minimize damage to the surrounding parenchyma and critical structures. Irreversible electroporation (IRE) and high-frequency IRE (H-FIRE), colloquially called pulsed-field ablation (PFA), utilize high-amplitude, low-energy pul...

Endothelial cell damage after cold preservation and reperfusion injury causes deterioration of the endothelial barrier and ultimately results in edema, leading to transplant failure. Here, a vascular microphysiological system (MPS) is introduced as a testbed to investigate the combinational effect of thermal and fluid perturbations (i.e., wall shea...

This study evaluates the effectiveness of isochoric impregnation during isochoric cold storage in extending the shelf life of strawberries. Strawberries in two different impregnation solutions—(1) sucrose solution and (2) sucrose solution containing calcium chloride (CaCl2) and ascorbic acid (AA)—were first stored in an isochoric chamber at −2 °C/4...

Efficient means of reducing food waste are critically needed to meet the demands of a growing global population, while mounting consumer interest in minimally-processed food products has simultaneously driven renewed interest in non-chemical preservation modalities. Here, we investigate the potential of low-pressure isochoric freezing (LPIF) at –1....

Cryopreservation under isochoric (constant volume) thermodynamic conditions has emerged as an alternative approach to conventional cryopreservation at constant pressure, leveraging the myriad effects of confinement to restrict the nucleation and growth of ice and protect complex biological matter at sub-0°C temperatures. This work seeks to review t...

Endothelial cell damage after cold preservation and reperfusion injury causes deterioration of the endothelial barrier and ultimately results in edema, leading to transplant failure. Here, we introduce a vascular microphysiological system ( MPS ) as a testbed to investigate the combinational effect of thermal and fluid perturbations (i.e., wall she...

Isochoric (constant volume) freezing is a novel food preservation technology that has demonstrated the ability to preserve food products at subfreezing temperatures in an unfrozen state, thereby avoiding the detrimental effects of ice formation. It minimizes the quality loss of fresh fruits and juices, increases their nutrient content, and reduces...

Isochoric freezing (IF) at −5°C/77 and −10°C/100 MPa was used to preserve carrot juice for 12 weeks. The juice qualities were compared to those using heat treatment (HT) at 95°C for 15 s followed by cold storage at 4°C. The native population of total aerobic bacteria, yeasts, and molds in isochoric frozen juice remained below the detection limit fo...

Pomegranate juice was treated by isochoric freezing (−15°C/130 MPa) for 24 h and then stored under three different conditions for up to 4 weeks: 4°C/0.1 MPa, 24°C/0.1 MPa, and −10°C/100 MPa. The juice microbiological stability and quality were compared to those using heat treatment at 95°C for 15 s followed by cold storage at 4°C. Heat‐treated and...

This study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw milk in isochoric chambers in thermodynamic equilibri...

Directional freezing harnesses crystal growth development to create aligned solid structures or etchable patterns, useful for directed ice growth in cryobiology and cryoprinting for tissue engineering. We have delved into...

There is growing interest in using isochoric freezing and isochoric supercooling for the preservation of biological matter at subfreezing temperatures. Custodiol® is a commonly used intracellular composition type, subnormothermic preservation solution. It is anticipated that Custodiol® will also be used for isochoric freezing and isochoric supercoo...

This study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw milk in isochoric chambers in thermodynamic equilibri...

Background: Tumor Treating Fields (TTFields) is a non-invasive modality for cancer treatment that utilizes a specific sinusoidal electric field ranging from 100 kHz to 300 kHz, with an intensity of 1 V/cm to 3 V/cm. Its purpose is to inhibit cancer cell proliferation and induce cell death. Despite promising outcomes from clinical trials, TTFields...

Temperature-controlled 3D cryoprinting (TCC) is an emerging tissue engineering technology aimed at overcoming limitations of conventional 3D printing for large organs: (a) size constraints due to low print rigidity and (b) the preservation of living cells during printing and subsequent tissue storage. TCC addresses these challenges by freezing each...

Corals are under siege by both local and global threats, creating a worldwide reef crisis. Cryopreservation is an important intervention measure and a vital component of the modern coral conservation toolkit, but preservation techniques are currently limited to sensitive reproductive materials that can only be obtained a few nights per year during...

The propensity of water to remain in a metastable liquid state at temperatures below its equilibrium melting point holds significant potential for cryopreserving biological material such as tissues and organs. The benefits conferred are a direct result of progressively reducing metabolic expenditure due to colder temperatures while simultaneously a...

This technical paper introduces a novel organ preservation system based on isochoric (constant volume) supercooling. The system is designed to enhance the stability of the metastable supercooling state, offering potential long-term preservation of large biological organs at subfreezing temperatures without the need for cryoprotectant additives. Det...

The professional practice of biomedical engineering can lead to severe consequences. These potential consequences do not differ from those expected in the exercise of the medical profession. Hence, the ethical framework of biomedical engineers (BMEs) should not differ substantially from the ethical framework of medical doctors (MDs). In medicine, a...

Temperature-Controlled-Cryoprinting (TCC) is a new 3D bioprinting technology that allows for the fabrication and cryopreservation of complex and large cell-laden scaffolds. During TCC, bioink is deposited on a freezing plate that descends further into a cooling bath, keeping the temperature at the nozzle constant. To demonstrate the effectiveness o...

This study was motivated by the increasing interest in finding ways to preserve organs in a supercooled state for transplantation. Previous research with small volumes suggests that the isochoric (constant volume) thermodynamic state enhances the stability of supercooled solutions. The primary objective of this study was to investigate the feasibil...

The propensity of water to remain in a metastable liquid state at temperatures below its equilibrium melting point holds significant potential for cryopreserving biological material such as tissues and organs. The benefits conferred are a direct result of progressively reducing metabolic expenditure due to colder temperatures while simultaneously a...

This is an exploratory study on the effect of electrolysis, delivered during the thawing stage of a cryoablation protocol, on tissue ablation. This treatment protocol, that combines freezing and electrolysis, is named “cryoelectrolysis”. In cryoelectrolysis the cryoablation probe is also used as the electrolysis delivering electrode. The study was...

Corals are under siege by both local and global threats, creating a wordwide reef crisis. Cryopreservation is an important intervention measure and a vital component of the modern coral conservation toolkit, but preservation techniques are currently limited to sensitive reproductive materials that can only be obtained a few nights per year during s...

A recent letter by (Fikiin et al., 2023) has sought to recontextualize and question aspects of our previous theoretical work published in this journal, concerning “isochoric freezing” of food matter (Powell-Palm and Rubinsky, 2019). They present questions related both to that work and to isochoric freezing more broadly, and in the present letter, w...

Background: Pancreatic islet transplantation via infusion through the portal vein, has become an established clinical treatment for patients with type 1 diabetes. Because the engraftment efficiency is low, new approaches for pancreatic islets implantation are sought. The goal of this study is to explore the possibility that a non-thermal irreversi...

In the present study, the effect of isochoric supercooling at − 2.5 °C and isochoric freezing at − 2.5 °C/12 MPa on the qualitative attributes of arils from whole pomegranates (cv. “Wonderful”) and fresh-cut arils preserved for 30 days was investigated and compared with cold storage at 5 °C/95% RH and isobaric freezing at − 2.5 °C/0.1 MPa. Mass, to...

Isochoric impregnation was explored as a novel pressure‐assisted infusion technique to fortify plant materials with bioactive compounds. Apple and potato cylinders were impregnated with a sucrose solution containing 4% ascorbic acid (AA) while freezing under isochoric conditions. Isochoric impregnation resulted in greater infusion of AA compared to...

This is a technology paper on the design of and test results from an 11-liter isochoric (constant volume) chamber, for the preservation of large, organs in a supercooled state. Details of the design are given, as well as a proof that the chamber is isochoric. Five repeats show that in this large chamber, ice nucleation of steam distilled water occu...

A 3D printing technology that facilitates continuous printing along a combination of cartesian and curvilinear coordinates, designed for in vivo and in situ bioprinting is introduced. The combined cartesian/curvilinear printing head motion is accomplished by attaching a biomimetic, flexible, "tendon cable" soft robot arm to a conventional cartesian...

The eutectic is fundamental to multicomponent systems, defining the lowest temperature at which a given liquid phase is stable. Although binary aqueous eutectics have been broadly characterized at atmospheric pressure, eutectic data at high pressure are scarce, leaving critical gaps both in the data available for modeling and in our understanding o...

Aqueous supercooling provides a method by which to preserve biological matter at subfreezing temperatures without the deleterious effects of ice formation. The extended longevity of the preserved biologic is a direct result of a reduction in the rate of metabolism with decreasing temperature. However, because the nucleation of ice from a supercoole...

Stable aqueous supercooling has shown significant potential as a technique for human tissue preservation, food cold storage, conservation biology, and beyond, but its stochastic nature has made its translation outside the laboratory difficult. In this work, we present an isochoric nucleation detection (INDe) platform for automated, high-throughput...

Background Tumor Treating Fields (TTFields), are a novel, non-invasive tissue ablation technology for treatment of cancer. Tissue ablation is achieved through the continuous delivery of a narrow range of electromagnetic fields across a tumor, for a period of months. TTFields are designed to affect only cells that divide and to interfere with the ce...

We introduce an isochoric (constant-volume) supercooling cryomicroscope (ISCM), enabling the ice-free study of biological systems and biochemical reactions at subzero temperatures at atmospheric pressure absent ice. This technology draws from thermodynamic findings on the behavior of water in isochoric systems at subfreezing temperatures. A descrip...

Porous dielectric membranes that perform insulator-based dielectrophoresis or electroosmotic pumping are commonly used in microchip technologies. However, there are few fundamental studies on the electrokinetic flow patterns of single microparticles around a single micropore in a thin dielectric film. Such a study would provide fundamental insights...

Low-temperature biopreservation and 3D tissue engineering present two differing routes towards eventual on-demand access to transplantable biologics, but recent advances in both fields present critical new opportunities for crossover between them. In this work, we demonstrate sub-zero centigrade preservation and revival of autonomously beating thre...

An efficient global cold food chain is critical to the sustainability of the growing world population, and it is anticipated that the global frozen food market will reach $404.8 billion by 2027. Frozen foods are typically stored under conventional industry-standard isobaric (constant-pressure) conditions at sub-freezing temperatures, however, which...

Stable aqueous supercooling has shown significant potential as a technique for human tissue preservation, food cold storage, conservation biology, and beyond, but its stochastic nature has made its translation outside the laboratory difficult. In this work, we present an isochoric nucleation detection (INDe) platform for automated, high-throughput...

Irreversible electroporation (IRE) is a non-thermal tissue ablative technology that has emerging applications in surgical oncology and regenerative surgery. To advance its therapeutic usefulness, it is important to understand the mechanisms through which IRE induces cell death and the role of the innate immune system in mediating subsequent regener...

There is growing interest in the use of isochoric (constant volume) freezing for cryopreservation of biological matter. The goal of this study is to generate fundamental experimental data on the pressure temperature relation during the freezing of an isochoric system of aqueous solutions of two compounds, glucose and glycerol. Glucose and glycerol...

We present herein an experimental study on the ice-nucleation kinetics of two recently introduced aqueous supercooling modalities—oil-sealed isobaric supercooling and isochoric supercooling. A series of constant-cooling rate experiments compare the apparent nucleation temperatures of pure water supercooled under these modalities with conventional o...

Isochoric freezing is a pressure freezing technique that could be used to retain the beneficial effects of food storage at temperatures below their freezing point without ice damage. In this study, potato cylinders were frozen in an isochoric system and examined using full factorial combinations of three processing procedures (immersed in water, va...

Low-temperature ex vivo preservation and tissue engineering based on human induced pluripotent stem cells (hiPSC) represent two of the most promising routes towards on-demand access to organs for transplantation. While these fields are often considered divergent from one another, advances in both fields present critical new opportunities for crosso...

This study investigated the potential of isochoric freezing to preserve tomatoes. Isochoric freezing is an emerging technology that preserves biological matter at subfreezing temperatures without any ice damage. Isochoric freezing was compared with freezing under isobaric conditions and with preservation techniques used in the food industry: cold s...

Objective An experimental study for testing a simple robust algorithm on data derived from an electromagnetic radiation device that can detect small changes in the tissue/fluid ratio in a realistic head configuration. Methods Changes in the scattering parameters (S 21 ) of an inductive coil resulting from injections of chicken blood in the 0–18 ml...

The stability of solid–liquid interfaces during solidification is a physical phenomenon of fundamental interest with a wide range of practical applications, including the freezing of biological matter for medical and agricultural purposes. Much of the classical research in this field treats solidification in isobaric (constant-pressure) systems in...

The enhanced interest in greater convenience foods has recently led to the expansion of minimally processed potato products. This study investigated the effects of isochoric freezing on pre‐peeled potato cubes, including quality attributes (microstructure, texture, and color), nutritional value (ascorbic acid (AA) content, total phenolic content, a...

Isochoric freezing, different from isobaric (conventional) freezing, allows for storage below freezing temperatures without significant damage from ice formation. While several types of tissues have been successfully stored in sub‐zero isochoric conditions, it is unknown how isochoric freezing affects pathogenic microorganisms. Thus, the objective...

The aim of this work was to evaluate the effects of isochoric freezing on the quality of tilapia fillet. Isochoric freezing was compared to chilling, super-chilling, and freezing. Isochoric freezing showed muscle color alterations similar to the other preservation methods. All preservation methods resulted in softer fillets, with the isochoric froz...

Stabilization of supercooled liquids presents a fundamental challenge with broad practical implications. Here, we unify divergent aspects of bubble dynamics, thermodynamics, and nucleation theory to explore the influence of confinement on cavitation-induced nucleation, a principal destabilization mechanism in supercooled systems. We demonstrate tha...

When delivered across a cell, certain pulsed electric fields can cause an increase in the cell membrane permeability through a biophysical process known as electroporation. The current signals during the electric pulses could be used as a method for noninvasive electroporation measurement because of the sharp change in the conductivity of cells due...

This review summarizes the use of high-voltage electrical pulses (HVEPs) in clinical oncology to treat solid tumors with irreversible electroporation (IRE) and electrochemotherapy (ECT). HVEPs increase the membrane permeability of cells, a phenomenon known as electroporation. Unlike alternative ablative therapies, electroporation does not affect th...

Supercooling has recently emerged as a highly promising, multi-scale technique for low-temperature preservation of organs and tissues, preventing damaging ice formation while requiring relatively low doses of added cryoprotectants. However, current supercooling techniques are not thermodynamically stable; mild agitations can cause rapid and destruc...

Water expands upon freezing. What happens when water is cooled below 0 °C in an undeformable, constant-volume container? This is a fundamental question in materials thermodynamics, and is also relevant in biological, geological, and technological applications in which ice forms under nano-, meso-, or macroscale confinement. Here, we analyze the pha...

Three-dimensional (3D) bioprinting is one of the fastest advancing and most promising techniques for tissue engineering. However, despite numerous developments in3D bioprinting, issues of size scalability remain. Two primary factors limiting the scale of printable objects are the structural properties of the bioinks and the un-sustainable time it t...

Background Percutaneous image-guided tissue ablation (IGA) plays a growing role in the clinical management of solid malignancies. Electroporation is used for IGA in several modalities: irreversible electroporation (IRE), and reversible electroporation with chemotoxic drugs, called electrochemotherapy (ECT). It was shown that the combination of elec...

Efforts are currently directed towards improving the quality of vegetables after freezing and thawing. One of the methods under investigation is isochoric freezing. In this study, we evaluated isochoric freezing for preserving the quality of baby‐leaf spinach. We compared the properties of thawed spinach frozen to −4°C in an isochoric system with t...

Hemorrhagic stroke is one of the leading causes of premature death among economically disadvantaged populations. Treatments of these conditions require an early diagnosis. While CT and MRI are the medical gold standard for early diagnosis, these imaging modalities are rarely available in low-and middle-income countries. We present an unsophisticate...

The present study is part of an ongoing effort to develop a simple diagnostic technology for detecting internal bleeding in the brain, which can be used in lieu or in support of medical imaging and thereby reduce the cost of diagnostics in general, and in particular, would make diagnostics accessible to economically disadvantaged populations. The s...

Horizontal directional solidification techniques have been broadly utilized for the freezing of biological matter under conditions in which the freezing rate during solidification must be controlled and known. Directional solidification is used for diverse applications such as fundamental research on freezing of biological materials, cryopreservati...

Background: Nonthermal irreversible electroporation is a minimally invasive surgery technology that employs high and brief electric fields to ablate undesirable tissues. Nonthermal irreversible electroporation can ablate only cells while preserving intact functional properties of the extracellular structures. Therefore, nonthermal irreversible ele...

Freezing of the aqueous solutions that comprise biological materials, such as isotonic physiological saline, results in the formation of ice crystals and the generation of a hypertonic solution, both of which prove deleterious to biological matter. The field of modern cryopreservation, or preservation of biological matter at sub-freezing temperatur...

Irreversible electroporation (IRE), is a new non-thermal tissue ablation technology in which brief high electric field pulses are delivered across the target tissue to induce cell death by irreversible permeabilization of the cell membrane. A deficiency of conventional IRE is that the ablation zone is relatively small, bounded by the irreversible e...

While three-dimensional (3D) printing of biological matter is of increasing interest, current linear 3D printing processes lack the efficiency at scale required to mass manufacture products made of biological matter. This paper introduces a device for a newly developed parallel additive manufacturing technology for production of 3D objects, which a...