In Vitro Analysis of the Co-Assembly of Type-I and Type-III Collagen

Abstract

An important step towards achieving functional diversity of biomimetic surfaces is to better understand the co-assembly of the extracellular matrix components. For this, we study type-I and type-III collagen, the two major collagen types in the extracellular matrix. By using atomic force microscopy, custom image analysis, and kinetic modeling, we study their homotypic and heterotypic assembly. We find that the growth rate and thickness of heterotypic fibrils decrease as the fraction of type-III collagen increases, but the fibril nucleation rate is maximal at an intermediate fraction of type-III. This is because the more hydrophobic type-I collagen nucleates fast and grows in both longitudinal and lateral directions, whereas more hydrophilic type-III limits lateral growth of fibrils, driving more monomers to nucleate additional fibrils. This demonstrates that subtle differences in physico-chemical properties of similar molecules can be used to fine-tune their assembly behavior.

Collagen: quantification, biomechanics and role of minor subtypes in cartilage

“…167 ). In fibrocartilage, collagen type I can form fibrils by itself, but it can also form heterofibrils with collagens III and V 168,169 . The fibril size in fibrocartilage can vary greatly by location, from 35-nm fibrils at the meniscus surface to 120-nm fibrils below 170 .…”

Collagen Hydrogel Functionalized with Collagen-Targeting IFNA2b Shows Apoptotic Activity in Nude Mice with Xenografted Tumors

“…Collagen solutions with or without IFNA2b or IFNA2b-CBD are fluid at low temperatures, but they form porous gels that trap an abundance of water (Figure ) when the temperature reaches a critical point of phase transition by rheological tests (Figure ). Indeed, IFNA2b and IFNA2b-CBD increase this phase transition temperature (Figure ), possibly because the proteins lower the hydrophobicity of collagen. , In any case, the injectability of collagen gel minimizes trauma during administration . In addition, collagen gels may fill irregularly shaped cavities left by surgical excision of solid tumors and thereby improve appearance, so that the collagen hydrogel with IFNA2b-CBD can be an adjuvant therapy after surgical excision to affect residual tumor cells for solid tumor treatment.…”

“…Indeed, IFNA2b and IFNA2b-CBD increase this phase transition temperature (Figure 2), possibly because the proteins lower the hydrophobicity of collagen. 38,39 In any case, the injectability of collagen gel minimizes trauma during admin-istration. 38 In addition, collagen gels may fill irregularly shaped cavities left by surgical excision of solid tumors and thereby improve appearance, 19 so that the collagen hydrogel with IFNA2b-CBD can be an adjuvant therapy after surgical excision to affect residual tumor cells for solid tumor treatment.…”

Macromolecular and nanoscale investigation of intermolecular interactions driving the self-assembly of collagen

“…where ε 0 is the permittivity of vacuum, ε is the dielectric constant of the solution, k B is Boltzmann constant, T=300K is the temperature, c i is the concentration of the i-th ion, e=1.6×10 −19 C is the magnitude of the charge of an electron, and z i is the valency of the i-th ion. For ions, we use the buffer composition in our previous experimental study [14]; 30mM Na 2 HPO 4 , 10mM KH 2 PO 4 , and 200mM KCl. These yield κ −1 =5.6Å.…”

“…For such applications, it is important to understand and manipulate the interactions between collagens and between collagens and other materials. To this end, we investigated collagen self-assembly on a commonly used substrate, mica [12][13][14].…”