Research Terms
Nanotechnology Bioelectromagnetics Medical Sciences Cancer Treatment Breast Cancer Fluid Mechanics Fluid Physics Heat Transfer
Industries
Biotech Health Care Medical Devices Pharmaceuticals
See the link for up to date list of publications with URL links to the articles.
Biomedical Engineering Society, Member; 2012 - present
Society of Rheology, Member; 2000 - present
American Institute of Chemical Engineers, Member; 1995 - present
Audience if introduced to the field of nanotechnology, its definitions, its relevance, recent history, and potential applications. Examples from the presenter's research are included at the end.
Subject Areas:
Audience:
High School
Duration:
1 hour or less
Fee:
No Cost
These magnetic nanoparticles have greater magnetic capacity, translated to improved functional properties, than magnetic nanoparticles available, potentially decreasing the costs of nanoparticle used in a broad range of industrial and biomedical applications. The market value for nanoparticles in biotechnology and pharmaceuticals is expected to reach $79.8 billion in 2019. Magnetic nanoparticles are frequently used for biomedical applications, such as imaging, drug delivery and as therapeutic and diagnostic agents. Unfortunately, the maximum magnetic capacity of available particles are not fully exploited due to a large difference between the actual physical and the magnetic size of the particle. Researchers at the University of Florida can produce nanoparticles in which the particle’s magnetic core size closely matches its physical size. These nanoparticles have enhanced magnetic capacity for better performance in biomedical and industrial applications.
Nanoparticles with enhanced magnetic capacity for better performance in biomedical and industrial applications
Available magnetic nanoparticles from existing synthesis methods suffer inefficiencies due to the presence of a magnetically dead layer on the particle surface, which prevents them from operating at their maximum magnetic potential. Most efforts to enhance the magnetic capacity of nanoparticles focus on post-synthesis modification. In contrast, researchers at the University of Florida have developed a synthesis method that generates nanoparticles with the desired magnetic capacity, without a requirement for any further modification. This method encourages the formation of an iron oxide particle with a uniform phase, and avoids formation of the magnetically dead layer, thereby increasing the magnetic core size of the resulting nanoparticles.
This magnetic particle spectrometer surpasses available AC susceptometers and magnetic particle spectrometers because it uses high magnetic field amplitude, large frequency range, and specialized coils and signal analysis to remove background noise in order to accurately characterize a wide variety of magnetic particle properties. Magnetic particle imaging is a new biomedical imaging modality that has potential to provide real-time 3D imaging comparable to PET scanning, but without radioactive tracers. Currently, the global medical imaging industry is estimated at $27 billion and is expected to grow to $35 billion by 2020. Researchers at the University of Florida have created a magnetic nanoparticle spectrometer to produce high-resolution dynamic magnetization measurements from small quantities of magnetic particle suspensions. This magnetic nanoparticle spectrometer provides a wide range for both field amplitude and frequency, and also provides background noise cancellation and feed-through reduction features, an improvement on available technologies. The system also has a relaxometer mode for mimicking the magnetic fields imparted by an MPI scanner. Beyond the uses in magnetic particle imaging, this magnetic nanoparticle spectrometer has potential application for characterizing magnetic particles for magnetically triggered drug delivery, biosensing and thermal cancer therapy.
Magnetic particle spectrometer to enhance the magnetic field amplitude and frequency range for characterizing magnetic nanoparticle suspensions
This magnetic particle spectrometer enhances accuracy in measurements using both hardware (balancing coils and active electronic cancellation) and software (background subtraction). It measures the underlying dynamic phenomena of the nanoparticles in suspensions. These measurements can evaluate the suitability of different particles for magnetic particle imaging applications and provide feedback to improve their synthesis. The complete system design and wide range of operation provides significant advantages over existing magnetic particle characterization technologies. The specialized coil design allows for increased sensitivity and accuracy, while decreasing background noise and the need for motion of the sample, a significant leap forward from available AC susceptometers.
This magnetically-triggered drug delivery platform can deliver a wide array of nano-medicines to targeted cells in the body. Nanotechnology is a growing science that is useful in targeting and treating cancerous cells and other harmful agents. The global market for nanoparticles in life sciences is estimated at over $30 billion. While a variety of available nano-medicines allow for encapsulation and delivery of drugs, the mechanism for release is either passive or requires a response to environmental stimuli; most of these approaches do not allow for externally controlled drug release. These magnetically-triggered drug delivery vehicles would respond to an applied alternating magnetic field by releasing a drug, enabling an unprecedented level of control over the spatial and temporal distribution of a drug. This provides clinicians with alternatives to maximize drug efficacy while minimizing side effects.
Magnetically-triggered drug delivery platform for precise encapsulation and externally controlled, targeted delivery of therapeutics
University of Florida researchers have developed a magnetically-triggered drug delivery platform comprising magnetic nanoparticles coated with a biocompatible polymer and conjugated to therapeutic agents through a thermally labile bond. Upon application of an alternating magnetic field, the magnetic nanoparticles release thermal energy, breaking the bonds and actuating the release of the drug. In the absence of the magnetic field, the drug remains encapsulated in the biocompatible polymer shell. The design of these magnetically-triggered drug delivery vehicles is general enough to make this platform nanotechnology attractive for the delivery of a wide array of therapeutic agents, such as small molecule drugs, peptides, and genetic material. In addition, the vehicles could co-deliver multiple therapeutic agents.
These magnetically templated tissue engineering scaffolds for biomedical applications, particularly as nerve guides for peripheral nerve injury repair. Peripheral nerve injuries (PNI) have a significant socioeconomic impact, resulting in over 8 million restricted activity days and over 5 million disability days per year. Over 200,000 PNI repair procedures are performed yearly in the U.S., with an estimated market for transected peripheral nerve injury repair of about $1.32-$1.93 billion. The current approach for repairing nerve injuries with gaps greater than 2 cm is autografts, commonly from the patient’s sural nerve. However, autografts have significant morbidity and functional deficit at the donor site, are not readily available, and matching the size of the donor nerve to the repaired nerve is often difficult. In addition, studies indicate motor function recovery occurs in only 40 to 50 percent of patients. A need exists for a bioengineered peripheral nerve scaffold with architectural and chemical components of natural peripheral nerve tissue, facilitating the repair of any size nerve gaps.
Researchers at the University of Florida have developed magnetically templated, biocompatible tissue engineering scaffolds, with aligned porosity with dimensions greater than 2 cm, for tissue growth and repair, including peripheral nerve repair. The magnetic particles can control the direction and extent of the aligned pores and channel structures of the scaffolds, allowing for peripheral nerve injury repairs of more considerable distances.
Magnetically template tissue engineering scaffolds with aligned pores and channels for tissue growth and repair, including peripheral nerve repair
These magnetically templated tissue scaffolds use magnetic nanoparticles encapsulated in a dissolvable, biocompatible matrix material. The influencing magnetic field causes the microparticles to align, forming a plurality of lines and columns that are spatially aligned. The scaffolding material crosslinks and polymerizes to form a solid, three-dimensional scaffold structure around the nanoparticles. The magnetic nanoparticle matrix then dissolves to produce aligned voids and microchannels, with aligned porosities with dimensions greater than 2 cm within the scaffold, allowing for nerve repair of greater distances.
These nanoparticles leverage biocompatible coating and exceptional aggregation resistance to permeate organs for cryopreservation and nanowarming. Organ transplants deliver lifesaving care to tens of thousands of Americans each year, but the demand for transplants is about ten times greater than the available supply, taking untold lives. One immediate solution is to increase the lifetime for organ preservation since over half of intact organs are not being preserved long enough for transplant. Cryopreservation of organs at low temperatures without ice formation can extend lifetimes, but many cryopreserved organs are damaged by the temperature gradients between their surface and their interior during rewarming. A process known as nanowarming avoids this problem by generating heat with nanoparticles distributed uniformly within the organ. However, many candidate nanoparticles clump together during cryopreservation, reducing heating uniformity and damaging organs.
Researchers at the University of Florida have developed a superparamagnetic iron oxide nanoparticle (SPION) whose layered polyethylene glycol (PEG) coating reduces aggregation and whose response to magnetic fields enables fast, controllable rewarming rates. Their PEG coating is also biocompatible, reducing toxicity to and preventing immediate clearance from tissue. Their magnetic properties also enable quantitative verification of removal after nanowarming using magnetic particle imaging.
Magnetic nanoparticles with high colloidal stability for controlled, uniform rewarming of cryopreserved organs
The intrinsic magnetism of SPIONs causes them to oscillate under alternating magnetic fields. When SPIONs are present in an organ, their oscillation adds heat, a process known as nanowarming. The ability of SPIONs to survive and spread out in the bloodstream, and of magnetic fields to travel through tissue, combine to ensure that nanowarming distributes heat uniformly throughout the tissue. Uniform heating is critical when rewarming cryopreserved organs (organs that have been vitrified into a non-crystalline solid, rather than simply frozen) that suffer damage under nonuniform heating. Introduction of SPIONs to the cryopreservant fluid during the vitrification process enables later rewarming, but the vitrification as well as the cryopreservant fluid itself present harsh conditions that can cause degradation or clumping of the SPIONs, ruining the uniformity of the heating.
The polymer coating of the SPIONs is the key to resisting degradation and clumping, and also impacts other desirable properties such as biocompatibility and blood circulation lifetime. While conventional PEG coatings contain exposed amines which cause clumping, these SPIONs coated with an additional layer of PEG have no exposed amines, preventing clumping for multiple weeks. This, along with their fast rewarming rates externally controllable via the alternating magnetic field, making these SPIONs ideal for the non-damaging rewarming of cryopreserved organs.
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