After nearly a decade-long federal moratorium on embryonic stem cell research, regenerative medicine took a serious hit. Yet sometimes from adversity comes innovation. Like-minded regenerative medicine industry leaders illustrated this point at the recent “New York Stem Cell” summit. With novel cell lines involving pure pluripotent embryonic progenitors and “smart” allogenic adult stem cells, to new techniques that include ultrasonic cavitation for the safe, effective separation of the stromal vascular fraction, directional freezing for effective biopreservation of cellular tissue, as well as the clinical application of high-pressurized cultured autologous hyaline cartilage implants, the future of regenerative medicine has never looked brighter.
“There is an old adage in biotech,” said Michael West, Ph.D., CEO of BioTime: “Show me something that I can make.” Since pluripotent embryonic stem cells, by nature, are highly heterogeneous, successfully manufacturing a pure cell product that alleviates all FDA safety concerns has been particularly difficult.
Inspired by Craig Venter, Ph.D.’s approach to sequencing the human genome, BioTime adopted shotgun embryonic cell cloning. By randomly growing a small amount of monoclonal embryonic stem cells with a variety of differentiating signal cues (growth factors such as retinoic acid or bone morphogenetic protein), BioTime developed several embryonic progenitor cells (ACTCellerate™ lines).
ACTCellerate lines exhibit less broad pluripotency but are still relatively undifferentiated with regard to specific downstream tissue. Since ACTCellerate lines are less primitive than embryonic stems cells, they are manufactured with greater purity and still show strong potential for directed clinical therapy against a variety of disease and damaged tissue, Dr. West explained.
Presently BioTime, with the use of microarray, real-time PCR, and protein analysis, has carefully characterized the entire transciptome of over 200 types of ACTCellerate lines in a variety of tissue lineages including chrondogenic, osteogenic, myogenic, and neurogenic cells.
With the process of Fate Space Screening, which involves the random testing of the ACTCellerate lines with different growth factors and culture conditions, BioTime has begun to develop a phylogenetic map of the exact mechanisms and pathways involved in the differentiation of embryonic cells into specific tissues.
While BioTime is interested in the commercialization of its products, it also understands that in order to succeed in the complete and novel elucidation of all tissue differentiation pathways, national and international research collaboration is both a goal and a necessity.
As a way to advance stem cell research and inspire collaboration, BioTime, with Xennex (GeneCards®), is also developing LifeMap, which Dr. West said is the first database to combine known genomic data with the eventual mapping of all development tissue lineage pathways and corresponding signaling mechanisms.
Early Lineage Adult Cells
“ELA® cells are genetically and phenotypically distinct from other adult stem cell populations,” noted Pamela Layton, CEO of Parcell Laboratories. They are an early-lineage adult pluripotent cell line found throughout the body, which, according to laboratory studies, can differentiate into endodermal, mesodermal, and ectodermal tissue.
ELA cells lack cell surface biomarkers commonly associated with other stem cell populations and are immune privileged. By not inducing an immune response, ELA cells can be safely donated without the need of HLA matching. Furthermore, with these cells, without the need for immunosuppressant medication, the risk of cellular rejection and graft-versus-host disease may be minimized.
In rats, ELA cells donated from college-aged donors, combined with a demineralized bone scaffold, induced more effective and consistent bone formation than mesenchymal stem cells extracted from college-aged donors, as well as bone marrow aspirate, the “gold standard” in spine repair.
With meticulous donor screening, as well as isolation, processing, and freezing techniques, Layton said that Parcell can successfully harvest large enough quantities of pure ELA cells to not require subsequent cellular expansion. This can result in reduced costs and minimize unnecessary laboratory manipulation.
Layton remarked that Parcell is presently working in collaboration with several top industry leaders to determine the therapeutic applications of ELA cells against many disease indications. In 2010, in collaboration with Alphatec Spine, Parcell developed an ELA-based product, PureGen Osteoprogenitor Cell Allograft™, which has shown “a significant clinical benefit in bone regeneration of the spine.”
Harvesting Stem Cells with Sound
“At the end of the day with our technology, we make more cells, cheaper cells, and faster cells,” said Steven Victor, M.D, CEO of Intellicell Biosciences, when comparing Intellicell technology to other adipose stromal vascular fraction (SVF) harvesting methods.
Intellicell uses ultrasonic cavitation, a phenomenon that occurs with the formation and collapse of microscopic bubbles as a result of an ultrasound pressure gradient. Ultrasonic cavitation strictly utilizes mechanical forces to separate the SVF from white adipose tissue. It does not require the addition of exogenous digestive enzymes, or other purification steps that are common with other SVF harvesting methods.
Additionally, since ultrasonic cavitation lyses red blood cells, the blood does not need to be removed and the “hematopoietic stem cells, plasma, platelets, and other important health factors of the blood” are retained in the SVF population, Dr. Victor said.
Compared to other methods, ultrasonic cavitation provides over twice as many SVF cells from less than half the extracted adipose tissue, with minimal laboratory manipulation. For these reasons, this product falls under FDA 361 guidelines, which will allow the extracted SVF cells to be used off-label and at the discretion of licensed physicians.
Composed of mesenchymal stem cells and other important cell populations, including pre-adipocytes, endothelial cells, smooth muscle cells, fibroblasts, important immune cells, as well as variety of growth factors, the SVF, according to Dr. Victor, is more therapeutically efficacious than stem cells alone. It is pluripotent, exhibits homing characteristics, and can provide clinical regenerative healing in a variety of tissue. Furthermore, since the SVF is extracted from the patient, it is also autologous with minimal risk of an immune response.
Presently Intellicell is largely researching the clinical application of this technology in “three therapeutic worlds”: cosmetics, peridontal medicine, and orthopedics. It is in the process of organizing several clinical trials, including a multicenter study in collaboration with a sports orthopedic medical doctor on the use of ultrasonic cavitation-purified adipose SVF on osteoarthritis of the knee.
To extend its clinical application beyond the focus of Intellicell, the ultrasonic cavitation technology is also licensed worldwide to industry and research leaders to test its clinical effectiveness against other indications including wound healing, cardiac disease, multiple sclerosis, and autism.