Collagens I and III are involved in the formation of the extracellular matrix and presumably in the development of several diseases, such as atherosclerosis. In this study, stable collagen and collagen-decorin coatings were prepared on the inner surfaces of fused silica CEC capillaries, enabling study of the interactions between collagen and selected peptide fragments of apolipoprotein B-100 (apoB-100), the main protein of low-density lipoprotein (LDL) particles. Interactions of positive, neutral, and negative peptide fragments of apoB-100 were elucidated. The selected positive peptide contains the sequence involved in the interaction of LDL with LDL receptor and proteoglycans. Retention factors of the peptides that were determined without any voltage, by exploiting pressure, gave numerical information about interactions with the collagen coatings. The inclusion of decorin in the coatings confirmed the importance of glycosaminoglycans in mediating the interactions between collagens and apoB-100 peptide fragments. The studies support earlier findings that collagens I and III take part in the retention of LDL particles in the intima through binding with a specific positive site on apoB-100. The method developed is simple, but also inexpensive since only small amounts of peptides and collagens are required. Atomic force microscopy images provided valuable information about the topography of collagen and collagen-decorin coatings on the capillary wall.