Technology
Platelet-Rich Plasma (PRP)
Because of a lack of effective products, physicians have begun to look for ways to improve the healing of soft tissue and bone and are rapidly embracing the use of platelet-rich plasma (PRP) manufactured in the operating room from a patient's own (autologous) blood. PRP contains growth factors that accelerate healing and is being rapidly adopted for numerous clinical applications, including the repair of tendons, ligaments, cartilage, bone, skin wounds, and other applications. Normal platelet counts in human blood average approximately 200,000/μL; platelet-rich plasma (PRP) has a concentration about 3-5 times larger; it is this concentration of platelets and the natural growth factors contained within that accelerates tissue healing. There are, however, problems with the use of autologous PRP. Being a liquid, PRP is may not stay where it is injected and is rapidly absorbed by the body; some physicians are now advocating weekly injections. The commercially available platelet concentrators are not equal in their ability to concentrate platelets in sufficient numbers to produce the desired healing enhancement. The amount and bioactivity of certain key growth factors also depend on a patient’s age, significantly decreasing after 30 years; even in younger patient populations, there is significant variation patient-to-patient in the number of platelets and growth factors. Once the blood is spun to remove cells and concentrate the platelets, the remaining platelet-poor plasma (PPP) is typically discarded; such PPP contains numerous growth factors that do not occur in platelets (e.g., IGF, HGF), and discarding it may reduce the effectiveness of the PRP. There is also debate over whether the presence of leukocytes in the PRP is detrimental and whether the platelets should be pre-activated prior to injection. Carmell’s bioactive products are ready-to-use, plastic forms of PRP that slowly release the endogenous growth and regenerative factors as they degrade. Being well characterized and consistent lot-to-lot, Carmell’s products address all the concerns with using autologous PRP.
Biologically-active materials made from platelet-rich plasma.
Carmell manufactures its plastic biomaterials by removing the water from blood plasma. Glycerin is then added to the resulting powder and the “dough” is plasticized with the use of precisely controlled temperature and pressure. Unlike spun-down autologous PRP where the platelet-poor plasma (PPP) is often discarded, the Company’s process includes all the growth and regenerative factors not only concentrated in the platelets, but also contained in the plasma (PPP). As such, Carmell’s plastics contain a rich concentration of natural proteins and minerals that have evolved by nature to heal wounds. These novel plastics degrade by proteolytic means, and the Company’s data show that the degradation time can be controlled by varying the amount of cross-linking agent used in its manufacture as well as the processing parameters. The Company has made plastic materials ranging in physical properties from elastomeric sheets to plastic parts exhibiting the stiffness and tensile properties of bone. The Company has tested various bioplastics in animal models, and results show no undue inflammatory response as well as controlled degradation.
The natural (endogenous) growth factors present in Carmell’s materials are directly involved in bone and soft tissue healing processes. PDGFs (platelet derived growth factors), TGFs (transforming growth factors), IGFs (insulin-like growth factors), and FGFs (fibroblast growth factors) give rise to the plastics’ osteogenic properties, encouraging the healing and formation of new bone. Likewise, these same growth factors are known to support the growth of new blood vessels.
The Company has exclusively licensed patents from Carnegie Mellon University, with additional U.S. and foreign filings. Its proprietary process allows the creation of plastic materials that retain their bioactivity even after sterilization and months of storage at room temperature.
Carmell’s first product is the REPAIR™ Bone Putty, a putty form of the plasma-based plastics designed to fill bone defects. Competitive with Demineralized Bone Matrix (DBM), Carmell’s putty has been shown to be both osteogenic and osteoconductive in animal testing and accelerates the healing of bone injuries. The biologically-active filler degrades over 8-12 weeks, slowly bathing the injured bone with a concentration of natural growth and regenerative factors in physiological proportions. Unlike DBM, however, REPAIR Putty is well characterized and consistent lot-to-lot, and it is not osteoinductive - that is, it will not encourage heterotopic bone formation when placed in soft tissue. The putty is sterile and pre-loaded in a syringe, and with the aid of a “caulking gun” can be placed through a needle or cannula.
Other products include a Surgical Scaffold for soft tissue repair, which degrades over 4-6 weeks, accelerating the healing of injured tendons and ligaments.
Additional new products are under development that incorporate the Company’s novel PRP-based plastics that naturally accelerate healing of both soft and hard tissues.