Control of growth and inflammatory response of macrophages and foam cells with nanotopography

This could explain why we are getting atherosclerosis.
http://www.nanoscalereslett.com/content/pdf/1556-276X-7-394.pdf
Background
Recent fabrication of nanostructured materials with different surface properties has generated a great deal of interest for developing implant materials, i.e., cardiovascular, dental, orthopedic, percutaneous, subcutaneous, and auditory [1-5]. The interface between nanostructured materials and biological tissues is likely to vary dependent upon the surface properties of the nanomaterial. Understanding the degree of toxicity induced by the unique cellular interaction of nanostructured materials is a major concern before utilization in biomedical applications [6-8]. Therefore, fabricating biocompatible materials which are designed to perform specific functions within living organisms has become a key component for generating nanodevices for biomedical applications, including implants.  Macrophages play a critical role during innate and acquired immune responses through the phagocytosis of foreign material. During an immune response, macrophages are typically the first cell type to respond and will secrete proteins (cytokines and chemokines) in order to recruit more immune cells to the site of injury. Atherosclerosis is a pathological process that takes place in the major arteries and is the underlying cause of heart attacks, stroke, and peripheral artery disease. The earliest detectable lesions, called fatty streaks, contain macrophage foam cells that are derived from recruited monocytes. The formation of these foam cells correlates to inflammatory responses [9-11]. In particular, immune cells such as monocytes and macrophages play a key role in mediating host tissue response to implants in the foreign body reaction. One study demonstrated that the macrophage receptor with collagenous structure (MARCO) displayed limited expression in healthy cells but increased in expression around the synovial fluid following hip replacements [12]. This study indicated that the presence of a foreign body can generate an immune response, and the continued presence of the foreign body can potentially lead to macrophage buildup and production of foam cells.  Recent reports have shown that microscaled landscapes are able to direct shape and migration of cultured cells. When cultured on ridges and grooves of nanoscale dimensions, cells migrate more extensively to the ridges than into the grooves. Cell shape is aligned and extended in the direction of the groove [13]. Osteoblasts grown on a fibrous matrix composed of multiwalled carbon nanofibers (100 nm in diameter) exhibit increased proliferation compared to those on flat glass surfaces [14-16]. Nanodots larger than 100 nm in diameter induced an apoptosis-like morphology for NIH-3T3 fibroblast cells [17]. Breast epithelial cells proliferate and form multicellular spheroids on interwoven polyamide fibers fabricated using electrospinning polymer solution onto a glass slide [18]. A 3-D nanofibrillar surface covalently modified with tenascin-C-derived peptides enhances neuronal growth in vitro [19].  The cardiomyoblast H9c2 shows induced cell adhesion and cytoskeleton organization on nanodot arrays smaller than 50 nm [20].
Recently, arrays of nanodots with defined diameter and depth have been fabricated using aluminum nanopores as a template during oxidation of tantalum thin films [21]. The pore size of aluminum oxide is controllable and uniformly distributed; the depth of dots depends on the
voltage applied; thus, it can serve as a convenient mold to fabricate tantalum into a nanodot array of specific diameter and depth. The structure containing nanodots of uniform size could serve as a comparable nanolandscape to probe cellular response at the molecular level.
Although many implant surface topographies are commercially available, there is generally a lack of detailed comparative histological studies at the nano-interface that document how these surfaces interact with living cells, in particular immune cells. In the present study, different sizes of nanodot arrays ranging from 10 to 200 nm were used to evaluate the growth
and inflammatory response of macrophages and foam cells.


Rest at the link, a total of 18 pages, baffle your doctor with questions from here.