Kinetics of blood component adsorption on poly(D,L-lactic acid) nanoparticles: Evidence of complement C3 component involvement

Abstract

After intravenous administration, nanoparticles suffer a major drawback in that they are rapidly and massively taken up by the cells of the mononuclear phagocyte system. The mechanisms involved in the opsonization, adhesion, and internalization of biodegradable nanoparticles by the mononuclear phagocyte system are still poorly understood. In this work, the kinetics of blood protein adsorption onto nanoparticles of poly(D,L-lactic acid) prepared by the salting-out technique was investigated. Nanoparticles of 312 nm were incubated for variable periods of time (5-60 min) in human serum and citrated plasma. After incubation, the particles were washed and the proteins detached from them, denatured, and analyzed by two-dimensional polyacrylamide gel electrophoresis. In plasma, the predominant protein was immunoglobulin G (IgG), and the amount adsorbed was not dependent on incubation time. Albumin amounts were high for short incubation periods but decreased as a function of time, whereas apolipoprotein E levels increased significantly as a function of the incubation period. Owing to the possible complement cascade inactivation by addition of citrate to plasma, the kinetics of adsorption was also evaluated in serum. In this medium, adsorption of complement C3 components onto the surface of the nanoparticles was clearly evidenced by spots of increasing intensity and area, reaching levels comparable to those of the omnipresent IgG. This result confirms the important role of complement components in the opsonization process of poly(D,L-lactic acid) particles.

Folic Acid Modified Poly(lactide‐co‐glycolide) Nanoparticles, Layer‐by‐Layer Surface Engineered for Targeted Delivery

“…In particular, the protein amount on the (PAA/PEI) 2 /PAA coated NPs was almost doubled and finally reached a value of 32 mg Á mg À1 NPs after 16 h incubation. These results imply that although the protein components on the NPs surface might be changing all the time during the incubation, [33][34][35] the overall adsorption of the proteins on the positively charged surfaces is rapidly equilibrated, due to charge attraction. The protein adsorption on the negatively charged surface is a process, which requires a relatively longer time than for the positive charged surfaces, though the adsorption process can be similar for both kinds of surfaces.…”

Drug transport to brain with targeted nanoparticles

“…1) Apolipoprotein E adsorption is not specific of polysorbate 80-coated surfaces because it was shown to adsorb onto pegylated PLA nanoparticles. 31,32 2) Polysorbate 80-coated poly-(methylmethacrylate) nanoparticles are not distributed into the brain after IV administration. 33 3) Replacing polysorbate 80-coated PBCA nanoparticles with polysorbate 80-coated polystyrene nanoparticles completely abolished dalargin brain delivery.…”

“…44,[73][74][75] After intravenous administration, the first step of the process that leads to the nanoparticle uptake by the MPS is the opsonization phenomenon. Opsonins, including complement proteins, apolipoproteins, fibronectin, and Igs, 31 interact with specific membrane receptors of monocytes and tissue macrophages, resulting in recognition and phagocytosis. It is generally admitted that hydrophobic surfaces promote protein adsorption and that negative surfaces are activators of the complement system.…”

Understanding the nanoparticle–protein corona using methods to quantify exchange rates and affinities of proteins for nanoparticles

“…A central methodological problem is to separate free protein from protein bound to nanoparticles, ideally employing nonperturbing methods that do not disrupt the protein-particle complex or induce additional protein binding. The preferred method to-date has been centrifugation, identifying the major serum proteins albumin, IgG and fibrinogen as being associated with a wide range of particles of seemingly disparate molecular composition (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Due to its high abundance, albumin is almost always observed on particles and may be retrieved even if it has relatively low affinity.…”