The nature of the protein corona forming on biomaterial surfaces can affect the performance of implanted devices. This study investigated the role of surface chemistry and wettability on human serum-derived protein corona formation on biomaterial surfaces and the subsequent effects on the cellular innate immune response. Plasma polymerization, a substrate-independent technique, was employed to create nanothin coatings with four specific chemical functionalities and a spectrum of surface charges and wettability. The amount and type of protein adsorbed was strongly influenced by surface chemistry and wettability but did not show any dependence on surface charge. An enhanced adsorption of the dysopsonin albumin was observed on hydrophilic carboxyl surfaces while high opsonin IgG2 adsorption was seen on hydrophobic hydrocarbon surfaces. This in turn led to a distinct immune response from macrophages; hydrophilic surfaces drove greater expression of anti-inflammatory cytokines by macrophages, whilst surface hydrophobicity caused increased production of proinflammatory signaling molecules. These findings map out a unique relationship between surface chemistry, hydrophobicity, protein corona formation, and subsequent cellular innate immune responses; the potential outcomes of these studies may be employed to tailor biomaterial surface modifications, to modulate serum protein adsorption and to achieve the desirable innate immune response to implanted biomaterials and devices.

We present strong evidence for the oxidation of conjugated polymers in the formation of conjugated polymer dots (CPdots) using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Although recent studies show that folding of the polymer chain into a compact 3D structure is involved in the formation of these nanoparticles, the process by which these intrinsically hydrophobic nanoscale particles circumvent aggregation in water is still not well understood. Zeta potential results show that these dots have a negatively charged surface at neutral pH, with a zeta potential and surface charge density of approximately -40 mV and (1.39 - 1.70) × 10(-2) C/m(2), respectively. In addition, quantitative elemental analysis of CPdots indicates that oxygen composes 7-13% of these nanoparticles. The overall results support the presence of chemical defects in forming a hydrophilic surface of CPdots. As a consequence, the charged surface contributes to inhibiting the aggregation of CPdots in water, leading to colloidal stability.

Nanoparticles have become an important utility in many areas of medical treatment such as targeted drug and treatment delivery as well as imaging and diagnostics. These advances require a complete understanding of nanoparticles' fate once placed in the body. Upon exposure to blood, proteins adsorb onto the nanoparticles surface and form a protein corona, which determines the particles' biological fate. This study reports on the protein corona formation from blood serum and plasma on spherical and rod‐shaped nanoparticles. These two types of mesoporous silica nanoparticles have identical chemistry, porosity, surface potential, and size in the y‐dimension, one being a sphere and the other a rod shape. The results show a significantly larger amount of protein attaching from both plasma and serum on the rod‐like particles compared to the spheres. Interrogation of the protein corona by liquid chromatography–mass spectrometry reveals shape‐dependent differences in the adsorption of immunoglobulins and albumin proteins from both plasma and serum. This study points to the need for taking nanoparticle shape into consideration because it can have a significant impact on the fate and therapeutic potential of nanoparticles when placed in the body.

The importance of nanostructured surfaces in a range of technological and biological processes is welldocumented within literature, yet often ill-understood. Simple and reliable methods for the preparation of nanotextured surfaces are required to advance both fundamental understandings of nanoscale phenomena and our capacity to design nano-engineered materials for specific applications. Nanoengineered surfaces are, for instance, needed to shed light on the effect of nanostructures' size and density on immune cells cytokine production. In applied bioengineering, nanostructured artificial surfaces could be specifically tailored to enhance the osteo-integration of implants. This study presents a versatile, plasma polymer enabled method for the generation of surfaces with well-defined nanotopography and tailored outermost surface chemistry. This was achieved by finely controlling the covalent bonding of gold nanoparticles of desired size to plasma-deposited poly(methyloxazoline) interlayer deposited on the material substrate. An additional 5 nm thin polymer was deposited over the nanostructures providing a uniformly tailored outermost surface chemistry while preserving the topography. This rapid, versatile, substrate independent, and scalable strategy for the preparation of a well-defined nanotopography surface has promising prospects in many fields relying on surface engineering, including food and membrane technologies, biomaterial and environmental engineering, sensing, marine sciences, and even pollution control.

Porous silicon (p‐Si) has been investigated as a novel delivery system for protein therapeutics. The loading of a model hydrophilic protein, Papain into anodised and stain etched p‐Si powders has been investigated using X‐ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR) and correlations made with the release kinetics. Variation in specific Papain (Amide I/II) and p‐Si (Si–Hx ) functional group absorbances with Papain loading level was characterised using FTIR, while the surface chemical distribution was assessed using XPS. A combination of burst release and sustained release of Papain was observed from p‐Si powders; this was dependent on p‐Si type and the Papain loading level. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)