Skip to main content
Log in

Mechanisms and dynamics of mechanical strengthening in ligament-equivalent fibroblast-populated collagen matrices

  • Published:
Annals of Biomedical Engineering Aims and scope Submit manuscript

Abstract

We have measured the dynamics of extracellular matrix consolidation and strengthening by human dermal fibroblasts in hydrated collagen gels. Constraining matrix consolidation between two porous polyethylene posts held rigidly apart set up the mechanical stress which led to the formation of uniaxially oriented fibroblast-populated collagen matrices with a histology resembling a ligament. We measured the mechanical stiffness and tensile strength of these ligament equivalents (LEs) as a function of age at biweekly intervals up to 12 weeks in culture using a mechanical spectrometer customized for performing experiments under physiologic conditions. The LE load-strain curve changed as a function of LE age, increasing in stiffness and exhibiting less plastic-like behavior. At 12 weeks, LEs had acquired up to 30 times the breaking strength of 1-week-old LEs. Matrix strengthening occurred primarily through the formation of BAPN-sensitive, lysyl oxidase catalyzed crosslinks. Sulfated glycosaminoglycan (GAG) content increased monotonically with LE age, reaching levels that are characteristic of ligaments. Cells in the LEs actively incorporated [3H]proline and [35S]sulfate into the extracellular matrix. Over the first three weeks, DNA content increased rapidly but thereafter remained constant. This data represent the first documentation of strengthening kinetics for cell-assembled biopolymer gels and the results suggest that this LE tissue may be a valuable model for studying the cellular processes responsible for tissue growth, repair, and remodeling.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Aggarwal, A. A syngeneic ligament equivalent, phase I: Mechanical properties of a fibroblast populated collagen lattices. S.B. Thesis, Department of Electrical Engineering and Computer Science, M.I.T., Cambridge, MA; 1987.

    Google Scholar 

  2. Barak, L.S.; Yocum, R.R.; Nothwagel, E.A.; Webb, W.W. Fluorescence staining of the actin cytoskeleton in living cells with 7-nitrobenz-2-oxa-1, 3-diazaole phallacidin. Proc. Natl. Acad. Sci. USA. 77:980–984; 1980.

    CAS  PubMed  Google Scholar 

  3. Bell, E.; Ivarsson, B.; Merrill, C. Production of a tissue-like structure by contraction of collagen lattices by human fibroblasts of different proliferative potentialin vitro. Proc. Natl. Acad. Sci. USA. 76:1274–1278; 1979.

    CAS  PubMed  Google Scholar 

  4. Bell, E.; Ehrlich, H.P.; Sher, S.; Merrill, C.; Sarber, R.; Bull, B.; Nakatsuji, T.; Church, D.; Bittle, D.J. Development and use of a living tissue equivalent. Plast. Reconstr. Surgery 67:386–391; 1981.

    CAS  Google Scholar 

  5. Bellows, C.G.; Melcher, A.H.; Aubin, J.E. Association between tension and orientation of periodontal ligament fibroblasts and exogenous collagen fibres in collagen gelsin vitro. J. Cell Sci. 58:125–138; 1982.

    CAS  PubMed  Google Scholar 

  6. Bellows, C.G.; Melcher, A.H.; Aubin, J.E. Contraction and organization of collagen gels by cells cultured from periodontal ligament, gingiva and bone suggest functional differences between cell types. J. Cell Sci. 50:299–314; 1981.

    CAS  PubMed  Google Scholar 

  7. Buttle, D.; Ehrlich, P. Comparative studies of collagen lattice contraction utilizing a normal and a transformed cell line. J. Cell Phys. 116:159–166; 1983.

    Article  CAS  Google Scholar 

  8. Chandrakasan, G.; Torchia, D.A.; Piez, K.A. Preparation of intact monomeric collagen from rat tail tendon and skin and the structure of the non-helical ends in solution. J. Biol. Chem. 251:6062–6067; 1976.

    CAS  PubMed  Google Scholar 

  9. Chandrasekhar, S.; Kleinman, H.K.; Hassell, J.R.; Martin, G.R.; Termine, J.D.; Trelstad, R.L. Regulation of Type I collagen fibril assembly by link protein and proteoglycans. Collagen Rel. Res. 4:323–338; 1984.

    CAS  Google Scholar 

  10. Coulson, P.C.; Bishop, A.O.; Lenarduzzi, R. Quantitation of cellular deoxyribonucleic acid by flow microfluorometry. J. Histochem. Cytochem. 10:1147–1153; 1977.

    Google Scholar 

  11. Dunn, G.A.; Ebendal, T. Contact guidance on oriented collagen gels. Exp. Cell Res. 111:475–479; 1978.

    Article  CAS  PubMed  Google Scholar 

  12. Ehrlich, H.P.; Borland, K.M.; Muffly, K.E.; Hall, P.F. Contraction of collagen lattice by peritubular cells from rat testes. J. Cell Sci. 82:281–294; 1986.

    CAS  PubMed  Google Scholar 

  13. Farndale, R.W.; Buttle, D.J.; Barrett, A.J. Improved quantitation and discrimination of sulphated glycosylaminoglycans by use of dimethylmethylene blue. Bioch. Bioph. Acta 883:173–177; 1986.

    CAS  Google Scholar 

  14. Franklin, T.J.; Gregory, H.; Morris, W.P. Acceleration of wound healing by recombinant human urogastrone (EGF). J. Lab. Clin. Med. 108:103–108; 1986.

    CAS  PubMed  Google Scholar 

  15. Goldman, R.D.; Schloss, J.A.; Starger, J.M. Organizational changes of actin like microfilaments during animal cell movement. In: Cell motility. Goldman, R.; Pollard, T.; Rosenbaum, J. (eds.) New York: Cold Spring Harbor Laboratory; 1976: pp. 217–245.

    Google Scholar 

  16. Goss, R.J. Bone and cartilage. In: The physiology of growth. New York: Academic Press; 1978: p. 64.

    Google Scholar 

  17. Grinnell, F.; Lamke, C.R. Reorganization of hydrated collagen lattices by human skin fibroblasts. J. Cell Sci. 66:51–63; 1984.

    CAS  PubMed  Google Scholar 

  18. Guidry, C.; Grinnell, F. Contraction of hydrated collagen gels by fibroblasts: Evidence for two mechanisms by which collagen fibrils are stabilized. Collagen Rel. Res. 6:515–529; 1986.

    Google Scholar 

  19. Guidry, C.; Grinnell, F. Heparin modulates the organization of hydrated collagen gels and inhibits gel contraction by fibroblasts. J. Cell Bio. 104:1097–1103; 1987.

    CAS  Google Scholar 

  20. Guidry, C.; Grinnell, F. Studies on the mechanism of hydrated collagen gel reorganization by human skin fibroblasts. J. Cell Sci. 79:67–81; 1985.

    CAS  PubMed  Google Scholar 

  21. Harkness, R.D. Mechanical properties of skin in relationship to its biological function and its chemical components. In: Elden, H.R. (ed.) Biophysical properties of skin. New York: John Wiley & Sons; 1971: pp. 393–436.

    Google Scholar 

  22. Huang, C. Physicochemical studies of collagen and collagen-mucopolysaccharide composite materials. Ph.D. Thesis, Department of Mechanical Engineering, M.I.T., Cambridge, MA; 1974.

    Google Scholar 

  23. Ignotz, R.A.; Massague, J. Transforming growth factor stimulates the expression of fibronectin and collagen and their incorporation into the extracellular matrix. J. Biol. Chem. pp. 4337–4345; 1986.

  24. Kagan, H. M. Characterization and regulation of lysyl oxidase. In: Mecham, A.P. (ed.) Regulation of matrix accumulation. New York: Academic Press; 1986.

    Google Scholar 

  25. Kim, Y.J.; Sah, R.L.Y.; Doong, J.-Y.H.; Grodzinsky, A.J. Fluorometric assay of DNA in cartilage explants using Hoechst 33258. Anal. Biochem. 174:168–176; 1988.

    Article  CAS  PubMed  Google Scholar 

  26. Labarca, C.; Paigen, K. A simple, rapid, and sensitive DNA assay procedure. Anal. Biochem. 102:344–352; 1980.

    Article  CAS  PubMed  Google Scholar 

  27. Lackie, J.M. Cell movement and cell behavior. Boston, MA: Allen & Unwin; 1986.

    Google Scholar 

  28. Lee, R.C.; Frank, E.H.; Grodzinsky, A.J.; Roylance, D.K. Oscillatory compressional behavior of articular cartilage and its associated electromechanical properties. J. Biomech. Eng. 103:280–292; 1981.

    CAS  PubMed  Google Scholar 

  29. McLeod, K.J.; Lee, R.C.; Ehrlich, H.P. Frequency dependence of electrical field modulation of fibroblast protein synthesis. Science. 236:1465–1469; 1987.

    CAS  PubMed  Google Scholar 

  30. Narayanan, A.S.; Siegel, R.C.; Martin, G.R., On the inhibition of lysyl oxidase by b-aminopropionitrile. Bioch. & Bioph. Res. Comm. 46:746–751; 1972.

    Google Scholar 

  31. Nimni, M.E.; Harkness, R.D. Molecular structure and functions of collagen. In: Nimni, M.E. (ed.) Collagen. Vol. I. Boca Raton, FL: CRC Press, Inc.; 1988: pp. 1–77.

    Google Scholar 

  32. Nusgens, B.; Merrill, C.; Lapierre, C.; Bell, E. Collagen biosynthesis by cells in a tissue equivalent matrixin vitro. Collagen Rel. Res. 4:351–364; 1984.

    CAS  Google Scholar 

  33. Reitzer, L.J.; Wice, B.M.; Kennell, D. Evidence that glutamine, not sugar, is the major energy source for cultured HeLa cells. J. Biol. Chem. 254:2669–2676; 1979.

    CAS  PubMed  Google Scholar 

  34. Roberts, A.B.; Sporn, M.B.; Assoian, R.K.; Smith, J.M.; Roche, N.S.; Wakefield, L.M.; Heine, U.I.; Liotta, L.A.; Falanga, R.; Kehrl, J.H.; Fauci, A.S. Transforming growth factor type: Rapid induction of fibrosis and angiogenesisin vivo and stimulation of collagen formationin vitro. Proceedings of the National Academy of Sciences. 83:4167; 1986.

    CAS  Google Scholar 

  35. Scott, J.E. Proteoglycan-fibrillar collagen interactions. Biochem J. 252:313–323; 1988.

    CAS  PubMed  Google Scholar 

  36. Silver, F.H. Biological materials: Structure, mechanical properties, and modeling of soft tissues. New York: New York University Press; 1987.

    Google Scholar 

  37. Skalak, R.; Chien, S. Hand book of bioengineering. Chapters 4, 6, 11, and 16. New York: McGraw Hill Book Company; 1987.

    Google Scholar 

  38. Snowden, J.M.; Swann, D.A. Effects of glycosaminoglycans and proteoglycan on thein vitro assembly and thermal stability of collagen fibrils. Biopolymers. 19:767–780; 1980.

    Article  CAS  Google Scholar 

  39. Stopak, D.; Harris, A.K. Connective tissue morphogenesis by fibroblast traction. Dev. Bio. 90:383–398; 1981.

    Google Scholar 

  40. Thomas, J. Nutrients, oxygen and pH in mammalian cell technology. Boston, MA: Butterworths; 1986.

    Google Scholar 

  41. Tomasek, J.J.; Hay, E.D. Analysis of the role of microfilaments and microtubules in acquisition of bipolarity and elongation of fibroblasts in hydrated collagen gels. J. Cell Biol. 99:536–549; 1984.

    Article  CAS  PubMed  Google Scholar 

  42. Tomasek, J.J. A serum factor promotes the generation of tension by fibroblasts in attached collagen lattices. J. Cell Biol. 111:148a: 1990.

    Google Scholar 

  43. Trelstad, R.L.; Silver, F.H. Matrix assembly. In: Hay, E. (ed.) Cell biology of extracellular matrix. New York: Plenum Press; 1981: pp. 39–63.

    Google Scholar 

  44. Weiland, T.; Faulstich, H. Amatoxins, phallatoxine, phallolysin and atamanide: The biologically active components of poisonousAmanita mushrooms. CRC Crit. Rev. Biochem. 5:185–260; 1978.

    Google Scholar 

  45. Weinberg, C.B.; Bell, E. A blood vessel model constructed from collagen and cultured vascular cells. Science. 231:397–400; 1986.

    CAS  PubMed  Google Scholar 

  46. Weinberg, C.B.; Bell, E. Regulation of proliferation of bovine aortic endothelial cells, smooth muscle cells, and adventitial fibroblasts in collagen lattices. J. Cell. Physiol. 122:410–414; 1985.

    Article  CAS  PubMed  Google Scholar 

  47. Weiss, P. Erzwingung elementarer strukturver schiedenheiten amin vitro wachsenden gewebe. Wilhelm Roux's Arch. 116: 438–554; 1929.

    Google Scholar 

  48. Weiss, P.In vitro experiments on the factors determining the course of the outgrowing nerve fiber. J. Exp. Zool. 68: 393–448; 1934a.

    Article  Google Scholar 

  49. Weiss, P. Secretory activity of the inner layer of the embryonic mid-brain of the chick, as revealed by tissue culture. Anat. Rec. 58:299–302; 1934b.

    Google Scholar 

  50. Wolff, J. The law of bone remodelling. Translated by P. Maquet and R. Furlong. Berlin: Springer-Verlag; 1986.

    Google Scholar 

  51. Woo, S.L.Y.; Buckwalter, J.A. Inquiry and repair of the musculoskeletal soft tissues. Park Ridge, IL: American Academy of Orthopedic Surgeons; 1988.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Huang, D., Chang, T.R., Aggarwal, A. et al. Mechanisms and dynamics of mechanical strengthening in ligament-equivalent fibroblast-populated collagen matrices. Ann Biomed Eng 21, 289–305 (1993). https://doi.org/10.1007/BF02368184

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02368184

Keywords

Navigation