While biomechanically suitable for cardiovascular, urological, and hernia repair applications, many polymers fail because of the body's inflammatory and thrombogenic response. But now, Histogen Inc. (San Diego), a regenerative medicine company developing solutions based on the products of newborn cells grown under embryonic conditions, has demonstrated that polymers coated with bioengineered human extracellular matrix (hECM) show a statistically significant reduction in immune-cell infiltration, foreign-body giant-cell formation, and fibrous capsule formation. In addition, the coating improves cell binding and proliferation, indicating that hECM could enhance the biocompatibility of various medical devices. Preclinical research on the insoluble, embryonic-like hECM has shown that the coating can reduce negative body responses and improve the performance of medical implantable devices.
"Device implants represent an important and expanding multibillion dollar market and have had a major impact on patient care," remarks Gail Naughton, CEO and chairman of the board of Histogen. "Problems such as fibrous capsule formation, poor tissue ingrowth, and neointimal hyperplasia resulting from suboptimal biocompatibility must be addressed to offer improved patient benefits. We are encouraged by the results with our embryonic-like matrix, which demonstrate its potential for reducing the foreign-body reaction, as well as improving and prolonging the life and function of implantable devices."
Testing, which was performed as part of a partnership with the National Research Council's Advanced Materials Division, involved coating hECM on several commonly used device materials, including nylon, polypropylene, and polyethylene terephthalate nonwoven scaffolds. Several common coating methods were employed. The hECM-coated and uncoated scaffolds were then surgically implanted in the subcutaneous space of SCID mice, after which histological samples of excised implants were assessed for inflammatory response, cellular infiltration, foreign-body giant cells, and capsule formation.
"Coating polymers with a naturally produced, all-human ECM masks the foreign device material and offers a physiological surface which supports healthy tissue infiltration and interaction," comments Michael Zimber, director of applied research at Histogen. "The hECM-coated polymers promoted a two-fold increase in normal cell proliferation as compared to uncoated polymers, as well as causing a significant reduction in the host inflammatory and fibrotic response to surgically implanted polymers."