Collagen I and III and their decorin modified surfaces studied by atomic force microscopy and the elucidation of their affinity toward positive apolipoprotein B-100 residue by quartz crystal microbalance

Abstract

Collagen, the major component of extracellular matrix (ECM) and the most abundant protein in the human body, is implicated in the development of atherosclerosis. Collagen types I and III were immobilized on fused-silica capillary to investigate their shape, size and structure by atomic force microscopy (AFM). For comparison, collagen was also immobilized on a mica surface. Our studies demonstrated that not only does the adsorption pattern on the substrate vary with the type of collagen, but also the substrate material plays an important role in the fibril formation process. Decorin, which promotes the binding of low-density lipoprotein (LDL) particles with collagen, was investigated for its effect on the fibrillogenesis. On both substrate materials, addition of decorin clearly reduced the fibril diameter of collagen surfaces. Moreover, a quartz crystal microbalance (QCM)-based biosensor approach was applied to clarify and evaluate the affinity of different collagen coatings immobilized on a silicon dioxide sensor chip toward apolipoprotein B-100, the major protein of LDL. The results confirmed the importance of collagen type and their fibrillogenesis on the binding of the positive residues of apolipoprotein B-100 on negatively charged collagen surfaces.

Preventing Obstructions of Nanosized Drug Delivery Systems by the Extracellular Matrix

“…Fiber diameter increased from 5.5 to 6.6 nm if the lower molecular weight HA was used, whereas the high molecular weight HA sample actually reduced fiber diameter to 5.1 nm . Addition of decorin also led to tighter and smoother gel structures compared to both unmodified collagen I and collagen–HA gels . However, under similar experimental conditions, gels have also been observed with both enlarged meshes and thinner fibers, probably due to swelling of HA .…”

“…QCM is characterized by high mass sensitivity; interactions between matrix components and particles may be measured with high accuracy. Interactions of biomolecules with collagen types have been measured by QCM . NMR analytics provide additional information about structure and dynamics within a short measurement time.…”

“…Interestingly, heparin is the only GAG for which this effect is observed. Other GAGs like decorin or HA led to dose‐dependent thinning of fibers in most cases . For example, the addition of 0.08 mg mL −1 decorin reduced fiber thickness from 1 to 0.35 µm; the addition of 2.5 mg mL −1 HA narrowed fibers from 0.8 to 0.5 µm .…”

“…Native and reconstituted matrices provide the most realistic conditions for mobility studies . Many studies were performed with less complex matrices like collagen or multicomponent ECM‐like gels that were composed of collagen combined with HA, decorin, alginate, or laminin and heparan sulfate . For results in such gels to be meaningful and applicable, despite their reduced fidelity to in vivo ECM, it is important that the matrices are homogeneously porous, with small pore sizes and a net negative charge.…”

Thermodynamic and kinetic approaches for evaluation of monoclonal antibody - Lipoprotein interactions

“…The Attana A100 Quartz Crystal Microbalance (QCM) instrument (Attana AB, Stockholm, Sweden) was used for label-free analyses of molecular interactions. LNB-Carboxyl sensor chips (Attana AB) providing low non-specific binding were used as the assay surface [2,3,8,9]. Chamber and sample volumes were…”