Use of collagen-hydroxyethylmethacrylate hydrogels for cell growth.

Abstract

Collagen-hydroxyethylmethacrylate hydrogels were prepared by polymerizing monomeric hydroxyethylmethacrylate in the presence of various concentrations of soluble native collagen. The resulting transparent hydrogels were evaluated as substrata for growth of IMR-90 human embryonic lung fibroblasts. Without collagen no significant growth occurred, whereas a dose-response curve expressing maximal cell growth against collagen concentration could be constructed quite readily by the use of appropriate hydrogels. The method allows for quantification of the collagen contribution to cell growth and, in a more general sense, provides the foundation for a relatively easy procedure to probe mechanisms of cell adhesion and cell differentiation. Among the many synthetic polymers presently used as biomaterials are those known as hydrogels. The term "hydrogel" refers to a broad class of polymeric materials that are swollen extensively in water but that do not dissolve in water (1). They have been used in a wide variety of biomedical applications and may be synthesized from monomers or monomers mixed with polymers. Hydrogels are attractive as biomaterials; they are highly permeable to water, ions, and small molecules (1). Hydrogels such as poly(2-hydroxyethylmethacrylate) (HEMA) and other synthetic polymers are relatively nontoxic and well tolerated when implanted in vivo (2, 3) or when added to an actively metabolizing tissue-culture system (4-6).The implantation of a biological material such as collagen results in good tissue tolerance both in vivo (7-15) and in vitro (16)(17)(18)(19)(20)(21). Collagen has been used in many biomedical applications such as in the dialysis membrane of an artificial kidney (7,(22)(23)(24), an artificial corneal membrane (8, 9), as vitreous body (10-12), in skin and blood vessels (13,14), and as a surgical hemostatic agent (15). In 1969, Chvapil et al. .(25) described good tissue tolerance in vivo of a collagen-hydrophilic polymer that they had constructed from a calf-hide collagen sponge immersed in HEMA monomer, allowing polymerization to occur on the sponge surface. They attributed the biocompatibility of this material to the porosity of the sponge, which permitted the ingrowth of blood vessels. In 1977, Shimizu et al. (26) reported high tissue compatibility of laminar copolymers of bovine collagen and various synthetic polymers that they had constructed by applying plasma discharge and y-irradiation to effect crosslinkage between a layer of collagen coated onto a layer of synthetic polymer. More recent studies involving collagen-cell surface interactions have focused on the role of fibronectin (27,28).In a study by Folkman and Moscona (29), poly(HEMA) coating was used as a means of preventing fibroblast growth on standard tissue-culture flasks (Falconware). Similarly, a morphologic study of mouse fibroblasts grown on syntheticcoated coverslips found poly(methylmethacrylate) and other polymers to be unfavorable surfaces for cell adhesion and growth (30). In the present communication, w...

Nerve fiber growth in culture on fibronectin, collagen, and glycosaminoglycan substrates

“…When polymerized, HEMA forms a clear hydrophilic gel. The methods for preparing HEMA gel substrates have been published (Civerchia-Perez et al, 1980;Carbonetto et al, 1982). Briefly, a solution of the molecule or molecules to be incorporated into the gel is added to a mixture of HEMA, ethylene glycol, sodium metabisulfite, and ammonium persulfate.…”

Microspheres for Enzyme Immobilization

“…In addition to the surface-coating method, collagen and other extracellular matrix (ECM) molecules can also been incorporated into microspheres by copolymerization method. The proteins could be added in a reaction mixture containing monomers and be polymerized in skeleton (Civerchia-Perez et al, 1980;Carbonetto et al, 1982;Woerly et al, 1993), or be mixed with polymerized polymer in appropriate solvents and attached on surface after removing the solvents (Stol et al, 1985).…”

Bioactive Hydrogels with Enhanced Initial and Sustained Cell Interactions

“…This corresponded to the large decreases in protein concentrations in low functionalization density gels, and could be expected due to decreased cell adhesion that typically occurs with decreased bioactive factor concentration. 30–31,39 …”