SBIR-STTR Award

Due to morbidity and limited amounts of material, alternatives to autologous grafts for bone repair are desirable. Mixtures of marrow stromal cells (MSC) and carrier matrices are known to augment bone repair. Increasing the number of MSC through ex vivo expansion may significantly increase the amount and rate of new bone formation. In this proposal, the ability of an automated clinical-scale cell culture system, the AastromReplicell (tm) Cell Production System (AR/CPS), to generate large numbers of MSC with osteogenic potential will be tested. Osteoprogenitor cells will be identified by flow cytometry (STRO-1 +, CD63+), ability to form mineralized matrix in vitro, and ability to form bone in SCID/NOD mice. Using small-scale cultures, parameters including medium perfusion rates, culture duration, and the effects of additives such as dexamethasone, ascorbate, FGF-2 and BMP-2, will be studied. Conditions found optimal for osteoprogenitor cell production will then be tested in the AR/CPS to confirm feasibility at the clinical scale. With successful completion of these studies, MSC generated in the AR/CPS will be tested in clinical trials to establish the safety and efficacy of these cells in treating nonunion fractures. In addition, this work may lead to novel treatments for skeletal diseases such as osteoporosis and osteoarthritis.

Thesaurus Terms:
biomedical automation, bone development, bone marrow, human therapy evaluation, mass tissue /cell culture, musculoskeletal disorder therapy, osteocyte, osteogenesis, stem cell bone fracture, cell morphology, clinical trial phase I, clinical trial phase II, connective tissue cell, osteoblast NOD mouse, SCID mouse, clinical research, flow cytometry, polymerase chain reaction

Due to morbidity and limited amounts of material, alternatives to autologous grafts for bone repair are desirable. Cells within the bone marrow are known to possess bone regenerative capacity, but they are limited in number. Increasing these osteoprogenitor cell populations through the use of ex vivo expansion technologies and combining these cells with a matrix material may significantly increase the amount and rate of new bone formation, and replace the need for autologous grafts. Phase I studies identified expansion variables for osteoprogenitor cell expansion and showed that this process can be scaled up into the automated clinical-scale cell culture system, the AastromReplicell(r) Cell Production System (ARS). In Aim 1 of the Phase II studies, optimization of the osteoprogenitor expansion process will continue. Optimization will be measured by not only biological performance in vitro and in vivo, but also the ease of commercialization of the expansion process. Specifically, the role of other cell populations in osteoprogenitor cell expansion and function will be determined, the minimal requirements for including exogenous factors in cultures will be identified, inoculation densities and maximized feeding schedules will be determined to support expansion from small volume bone marrow aspirates, the potential for expansion in an animal serum-free environment will be examined. In Aim 2, the angiogenic potential of these same cell products will be measured in vitro by colony assay and tube formation assays, as blood vessel formation is important for optimal bone regeneration. Aim 3 will validate optimal expansion processes in the ARS and evaluate bone and vascular regeneration in vivo in an ectopic mouse model. Aim 4 will include a Phase l/ll clinical trial using the selected cell product in combination with matrix material to treat tibial non-union fractures. Successful completion of these studies will lead to the development of a cell therapy kit that can be used for bone regeneration.

Thesaurus Terms:
osteocyte, stem cell, technology /technique development, tissue engineering bone regeneration, clinical trial phase I, clinical trial phase II, human therapy evaluation, limb fracture NOD mouse, SCID mouse, biotechnology, clinical research, human subject, patient oriented research