Fat Engineer, Glass Artist...

Fat Engineer, Glass Artist, and Deliverer of Drugs to Cancer

Lars Onslev, June 2012

Newly appointed Niels Bohr Professor brings Single Particle Science and Engineering and the potential for exciting new basic science aimed at cancer research for University of Southern Denmark

Needham with the tiny micropipet (the basis for his micromanipulation techniques) that he will bring to SDU to establish the Center for Single Particle Science and Engineering (SPSE).

http://www.youtube.com/watch?v=g7NAkAWTBqA

With the appointment of British scientist David Needham, Southern University now has the prospect of new ideas and approaches to all states of matter as microparticles of gas, liquid and solid, with special emphasis on designing new formulations for anticancer drug delivery.  David Needham has been awarded a Niels Bohr Visiting professorship established by the The Danish National Research Foundation/Danmarks Grundforskningsfond (DG) to attract top international researchers to Danish universities - and one can safely say that is the case here.

A lucky combination of chemistry, materials engineer, biomedical engineer, and cancer biologist, David Needham is a trained chemist who has been a professor for the past 25 years in the Engineering School at Duke University, in North Carolina, USA, and has also worked in the English pigment industry. But a great innate curiosity, and cancer cases in the immediate family caused him to attend seminars at the cancer institute in Nottingham while he was doing his PhD in gas solid catalysis in the Department of Physical Chemistry at Nottingham University in the late '70s.  Upon suggesting to his Professor (Daniel D. Eley, Chair Dept Physical Chemistry, PhD, ScD, (Cambridge) CChem, FRSC, FRS, OBE), that he would like to work I cancer research, he was advised to “work in cell membranes”.  Prof Eley called a colleague, Dennis Haydon, also an FRS, at the Physiological Laboratory in Cambridge, and David went for a “chat” (an interview in Cambridge), was hired, and started his journey of learning about and researching lipid membranes.  He envisioned that by learning more about lipid membranes he could work on cancer cells, but it turned out that what he discovered led him along a different pathway, to develop a new thermal sensitive liposome that could more effectively deliver chemotherapy directly to tumors in the body.

Developed by researchers in the early 70’s, Liposomes are tiny, artificial fat cells.  The researchers wanted to use them as containers for chemotherapeutic drugs, which in principle could be sent into the bloodstream and deliver the chemotherapeutic drug to the tumor.  The main advantage of this technique is that, by encapsulating the drug inside a lipid membrane bag, one can reduce the toxicity of drug, thus avoiding killing healthy cells. The thinking was that it would be able to treat cancer patients with higher doses of chemotherapeutic drugs.

But, although the idea sounded seductively simple, there were many obstacles that made it difficult to apply in clinical practice. It turned out that the body's immune system was so effective that it destroyed these objects long before they reached the tumor.  Shielding the liposome surface with a small, attached “Stealth” polymer meant that some of them reached the tumor, but even though they might accumulate in the tumor tissue, they did not release their drug fast enough to effectively kill the cancer.

With 6 years of post doc positions at Cambridge University UK, and at UBC Vancouver Canada, Needham retrained in the biophysics, and mechanochemistry of lipid bilayer membranes and, through this research, became interested in liposomes. The drug delivery dilemma (encapsulate drug to reduce toxicity, but then how do you get the drug out just at the tumor?) fascinated Needham.  The answer came from his basic studies in the mechanical, thermal, and exchange properties of single lipid vesicles that he studied in a microscope equipped with micropipet manipulation, --the kind of equipment and techniques Needham will establish here at SDU.

Promising liposomes
Although it took somewhat longer than the energetic and optimistic Needham had imagined, the breakthrough came in 1996 after cancer researcher and Radiation Oncologist at Duke, Dr. Mark Dewhirst said to Needham, “I need something I can heat and it releases drug”.  Based on his molecular exchange experiments with a molecule called a lysolipid, Needham had the idea that if he could trap this water soluble molecule in the membrane below its solid-liquid phase transition, and then have Mark Dewhirst heat it with his hyperthermia equipment, then maybe the encapsulated drug would leak out faster as the lysolipid either left the membrane or formed tiny porous defects.

While others in the late ‘80s had developed a temperature sensitive liposome, the temperature range it acted at (43-44oC) was a little higher than could routinely be attained in the clinic.  Thus was born a new kind of “Low Temperature Sensitive Liposome” (LTSL) that could release its drug in a matter of seconds at an attainable 41-42oC.  Needham submitted the invention disclosure in 1996 and received a patent for this new and promising type of liposome in 2001 (U.S. Patent No. 6,200,598 granted March 13, 2001, Temperature-sensitive liposomal formulation ). Keeping the polymer nano-coating so the immune system can no longer attack them, the liposomes were made heat-sensitive by incorporating just 10 mol% of the lysolipid. This meant that they were quite stable at 37 degrees, but released drug rapidly at 41-42 degrees.

Thus, after intravenous injection, the drug-containing LTSLs now survived the ride through the bloodstream and, by heating just the area where the tumor was with microwaves or radio frequency waves, Dr. Dewhirst could cause them to release the very toxic drug called doxorubicin quickly and deliver the chemotherapeutic agent just to the tumor.  It was a new paradigm for drug delivery, --release of drug in the blood stream, allowing the drug to diffuse rapidly into all cells of the tumor including the blood vessels themselves.  Not only was it anti-neoplastic, it was anti-vascular as well, and, in animal studies, the team at Duke showed that the blood vessels were shut down within 24hrs of just one hour of drug-heat treatment,; confocal microscope studies showed that the whole tumor was bright red with the fluorescent doxorubicin.

The formulation was licensed in 1999 by the American pharmaceutical company Celsion Corp. in order to develop the drug, now called Thermodox.  They conducted a phase I trial in order to determine if it can be used safely and securely in the treatment of various cancers.  The first cancer tested was Liver Cancer, (Hepatocellular carcinoma), using a radio frequency ablation probe to heat the center of the tumor to 60oC.  Despite this high heat at the core, the temperature drops off around the edge of the tumor and does not necessarily kill the dangerous micro-metastases around this periphery.  With Thermodox in the blood stream, the hope was that at temperatures below that which kills the tumor directly with heat, the still relatively high temperature would release drug and help to clear those margins from potentially new cancers.  The phase I results were very encouraging, and the agent is now in the last stages of a Phase III study in 700 patients in 71 hospital sites in 11 different countries. In beginning of 2013 they will know the results of this study, which looks to determine if the administration of Thermodox in conjunction with hyperthermia from the radio frequency ablation probe can extend the time it takes for tumors in the liver to progress.   If the FDA approves the groundbreaking technology, it could become a part of modern cancer treatment.

Journey of new drug particles through the bloodstream and into the Tumor.
It's been a long journey since 1978 when Needham made the bold decision to switch fields and try to work on cancer research.  And it is not over yet. Needham has chosen to continue his work at Southern University, because he has gotten some help and inspiration from local researchers both at SDU, as well as FARMA in Kobenhavn.

Next on Needham’s list is how to deliver the less water-soluble (more hydrophobic) drugs that have been, and continue to be, developed for anti-cancer treatments. One of the biggest challenges to delivering these classes of compounds, known as the “bricks of pharmaceuticals”, is how to formulate them so that they are not only delivered to the blood stream of the patient, but also reach the patient’s tumor in high enough quantities to be efficacious.  Here Needham’s inspiration comes from the way the body makes, transports, and uses its own fat as Lipoprotein nanoparticles, -- what we usually know as 'bad' cholesterol.  By reverse engineering the Low Density Lipoprotein, Needham has proposed to make pure-drug nanoparticles that will bind to and be taken in by cancer cells.  Cancer cells need unusually large amounts of lipids and protein in order to grow.  Consequently they over-express the receptors that bind and bring in LDLs in large quantities into their hungry cells.  Needham and collaborators are hoping to exploit the cancer cell's increased number of receptors and their big appetite for fat.  Basically, Needham’s concept is to “put it in their food”, i.e., make the drug nanoparticle “look like” an LDL, and have the cancer take it in as it would its natural nutrition, but have the particle contain one or more of the newer anticancer drugs that target its growth and metabolic pathways.

Here Needham proposes to use advanced microscope equipment and expertise for microscopy, available at Southern University. Professors Luis Bagatolli, Ole G. Mouritsen, and Chris Lagerholm from MEMPHYS, Center for Bio-membrane physics, and DaMBIC, (Danish Molecular Biomedical Imaging Center), have, for many years cooperated with Needham, and now with Niels Bohr Professorship, this cooperation is strengthened significantly, to the delight of both parties.  With a technique called “Single particle tracking” the SDU-DaMBIC researchers can watch how single fluorescent LDLs and the new nanoparticles might bind to and enter cancer cells.  These experiments are crucial to understanding exactly the formulation that will work to deliver them and have them taken in by a patient’s cancer.  Also, Needham’s micromanipulation studies will test models of particle stability and how they might survive in the blood stream long enough to be targeted with peptide ligands made by another SDU collaborator Stefan Vogel.  As you can imagine, developing a whole new treatment for cancer is a huge undertaking, but is one that the fearless Needham is ready to take on.  It will require additional funding for the work to be done at SDU, and could also engage other researchers in Denmark, including new collaborations at the Pharmacy School in Kobenhavn.

Inspired by a Train Wreck
It is striking that Needham’s ideas for these new research projects only really took shape in 2010 when he had to stay home and recover from a serious train accident.  In the 8 weeks he was told to take it easy and recover from the surgery required to repair a severed artery, two severed veins, and a crushed and lacerated pancreas (http://www.pratt.duke.edu/needham-recovery ), he spent the first two watching each stage  of the Tour de France (he could be still for 5 hrs!).  Once “le Tour” ended, his mind started to run wild with new ideas for the cancer treatment.  Needham is sure that this imposed pause has been crucial for him to have complete control over its frenmtidige research. And it's hard not to agree with him when he enthusiastically describes the new research projects that will include SDU, FARMA, and collaborators back at Duke.

Glassmaker
The second major project that Needham has developed over the past 10 years, consists of transforming living material into a glass.  This might sound strange, but Needham assures that there is a deeper meaning to it.
Needham has developed the micropipet technique to evaluate all states of matter as single particles.  One early experiment in 2002 was to observe and test a diffusion-solubility model for how micro-gas bubbles might dissolve in water,

Following this, he dissolved a solvent, ethyl acetate, used in drug formulations, into water just to see if it behaved in a similar way;  and it did, dissolving in exactly the same form as the model for gas.

On another occasion, he was using his micropipet technique to observe how fast a single microdroplet of water takes to dissolve in an oil, when he decided to dissolve some salt in the water.  The result was a very fast crystallization of the salt, but the droplet had to reach 11M sodium chloride before this happened spontaneously. This is shown in the video

Then, he decided to dissolve protein in the water, and see what happened. What he was expecting was that the water would leave the droplet (dissolving in the oil), and the protein might crystallize.  As shown in the video, the droplet shrank, went through the same refractive index as the surrounding oil, but basically no crystallization.

When he came in with the micropipet to interrogate the droplet, he found, as shown in the second video, that is was now a solid glassified bead of protein at a density of 1100 mg/ml.;

This prompted him to explore this as a potentially new processing method for protein dehydration and perhaps use it for forming, storing, and formulating a range of proteins and peptides, of current interest to the pharmaceutical industry. These experiments now form the basis for new collaborations with the Danish Technical Institute in Aarhus, with Thomas Kaasgaard PhD, a graduate of DTU. Many new medicines contain biologically active substances like proteins, which are not easy to store, transport, and administer in drug formulations.

Today, most of these proteins are simply freeze-dried as a powder, much as is used in the food industry. However, in addition to the high cost of such a procedure, which helps to make these kinds of medicine is very expensive, this processing can damage these very delicate natural molecules. Needham glassification technique, when it is fully developed, could be a cheaper and more effective than freezedrying. The imaginative Needham calls this technique microglassification or molecular water surgery. Briefly, microglassification can remove all the water associated with such molecular biological structures without damaging them by gently absorbing the water into a second liquid that acts as a kind of sponge. In this way, the biomaterial is converted into microglassified beads having a diameter of only a 50 millionth of a meter, --just less than the diameter of a human hair. Again, such new techniques will be explored with Pharmacy researchers at SDU and also at FARMA at KU.

With David Needham as the new Niels Bohr Professor, researchers at the University of Southern Denmark have got some exciting new dimensions in scientific research and the potential for new outreach and collaborations across Denmark, Europe and the USA. Since he also has a reputation for being a very inspiring teacher, it is quite certain that the students will also get a high yield out of Needham.