The interactions between biological systems and biomaterials are of great importance to regenerative medicine. Key to this understanding is assessing how cells react when presented with materials of varying physical and chemical properties. ‘Omics’ technologies such as MALDI mass spectrometry are ideal methods to examine the interactions between cell and surface.To this end we have built upon existing methods for the manufacture of bio-mimetic silica film surfaces with novel chemical and physical properties. Our methods have been able to produce silica surfaces under mild chemical conditions on a range of substrates suitable for use in cell culture applications. These surfaces can be fabricated with characteristics such as wetting properties ranging from hydrophobic to hydrophilic or even super-hydrophilic, depending on the methods used.The initial silica surface produced was trialed as a cell culture surface with a melanoma cell line (FM3) on both a hydrophilic silica surface and conventional cell culture polystyrene. After a period of culturing the culture media and lysed cells were examined using current MALDI based proteomic techniques to generate a peptide mass fingerprint characteristic of the cells cultured on both of the surfaces.Through comparison of the proteomic studies we have determined that the cell culturing surface can have a dramatic effect on the cell proteome. The melanoma line cultured on a hydrophilic silica surface showed a radically altered peptide mass fingerprint as compared with the cells cultured on the traditional cell culture polystyrene surface, both in terms of the proteins expressed into the cell culture media and the proteome of the cell itself. Examination of the morphology of the melanoma cells via optical microscopy showed that while the cells cultured on the different surfaces demonstrated similar morphological characteristics they showed important variations in their expressed proteome.Further investigation with different cells, including different cell surface chemistries in relation to culturing materials with different surface properties should provide great insight into the interactions between biological systems and materials destined for biological applications.

We demonstrate a new approach to electrically sense pathogens using cells as the receptor-sensing element. Electrical Cell-substrate Impedance Sensing (ECIS) was used to monitor the confluent growth of human dermal fibroblasts and their exposure to an anthrax simulant namely Bacillus cereus. ECIS was conducted at frequencies between 4 – 64 kHz and it was found to be an excellent measure of cell growth, micro-motion, and their overall intracellular and intercellular morphological responses when challenged with various agents. When exposed to the digestive enzyme trypsin we observed an instantaneous and unambiguous change in the capacitance, of approximately 67% at 32 kHz almost instantaneously. When exposed to the anthrax simulant Bacillus cereus spores, we observed no response during germination and a very small response when the bacillus cells thrived in the fibroblast growth media. The ECIS response was consistent with a live-dead assay whereby it was found that no cells had died and no significant morphological change was observed. While Bacillus cereus is in the same genetic family as Bacillus anthracis, its pathological lethality on the cellular level for fibroblasts was negligible. Our work shows that the ECIS measurements were an extremely sensitive measure of fibroblast morphological response. In this presentation, we will challenge prototype biosensors with other biological warfare simulant pathogens such as B. Subtilis or B. Atrophaeus (simulant for smallpox) as well as with against chemical warfare agents dimethyl methyl phosphonate (nerve agent – sarin) and 1,5 dichloropentane (blister agent – mustard gas).

This paper presents a novel implantable bio-micro-electro-mechanical system (Bio-MEMS) device for the localized treatment of cancer. The device uses a combination of heating (hyperthermia) and drug release to kill breast cancer cells. Cancer drug release is controlled by the use of modified poly(N-iso-propyl-acrylamide) (PNIPA) hydrogels with hydrophobic/hydrophilic copolymers and interpenetrating network structures. The gels are encapsulated in biocompatible poly-di-methyl-siloxane (PDMS) with micro-fluidic channels that convey the drug (paxlitaxel) to cancer cells/tissue. The thermo-sensitive properties (swelling) and fluid/drug release characteristics of the gels are elucidated along with the effects of localized heating with micro-wires. A synergistic killing of breast cancer cells is shown to occur as a result of the combined effects of localized cancer drug release and hyperthermia.

Micro and nanobiochips are of interest in biomedical applications like diagnostic, molecular screening and drug discovery. Recent advances in this field allow introducing technologies to create highly sensitive patterns. Classically, biochips are arrays of natural biomolecules locally immobilized on a surface. However, short life-time and poor stability of natural molecules when used out of their native conditions promotes introduction of alternative sensitive layers, particularly biomimetic polymers. Molecularly imprinted polymers (MIPs) represent a novel area of polymers capable of molecular recognition with the same affinity and selectivity as their natural counterparts. Their synthetic composition offers enhanced long-term stability compared to natural biomolecules. One other advantage of the polymeric matrix, characteristic of MIPs, is their powerful combination with micro and nanotechnologies to create biochips.Here, we present recent approaches developed in our groups to pattern MIPs at micro and nanoscale. First, Micropatterning tools were developed and referenced as contact and non-contact techniques. Contact method is based on array of silicon cantilevers fabricated by micromachining techniques and mounted on a three-stage automated spotter. This resulted in arrays of MIPs serially and precisely localized on a substrate, with resolution down to 20µm. Alternatively, a parallel approach was initiated by taking benefit of photopolymerization of MIPs to create patterns by photolithography. After spin-coating prepolymers, reticulation was initiated using a mask and resulting MIPs were in a wide variety of features with a resolution down to 1.5µm. By repeating sequentially deposition and local polymerization, a multi-array approach was also introduced. Final objective using these techniques is to compare performances of resulting MIPs in terms of sensitivity, integration, mass production and versatility.More recently, evolution of nanotechnologies made possible to engineer nanostructures. Main issues concern high throughput screening and testing with enhanced sensitivity by increasing the surface area of the MIP material. In this field, soft lithography and nanowires approaches are of major interest since they allow producing nanopatterns with high aspect ratio. Both methods succeeded to create MIPs nanofeatures. Nanofilaments were produced with elevated density, resulting in a factor 40 increase of the surface area compared to a flat surface. These conditions favored accessibility to binding sites and in molecular recognition assays, sensitive levels of detection were reached. A similar behavior was also observed when MIPs were patterned by soft lithography. Features were formed as a network of nanolines of 500nm wide and 400µm long with a pitch of 1µm, covering a large area of 400x400µm2. Thanks to developed techniques, we will conclude on perspectives on MIPs micro and nanopatterns as efficient alternatives to create advanced biochips.

Studies of hard biological materials such as marine shells, animal teeth, horns and bones have produced fascinating ideas for mimicking their micro/nanostructure in the lab. In this work we have analyzed the morphology ad mechanical properties of the nacreous portions of red abalone shells by SEM, TEM, XRD and the chemical compositions by EDS and ESCA. Bioinspired laminates were fabricated as multi-layers of several biocompatible materials: CaCO3 (aragonite)/polymer, ZrN/polymer and ZrO2/polymer for various polymer compositions, by using a combination of dc magnetron sputtering and pulsed laser deposition on glass, quartz and silicon substrates. Substrate temperatures for film deposition were varied in the range of 25-115°C. The films are composed of nanocrystalline or amorphous particles with different degrees of porosity as observed by TEM and AFM. High resolution TEM analysis at the inorganic/organic interface revealed well formed inorganic films which are separated by the polymeric layer (10-50 nm). The hardness values showed an increase for the inorganic film/polymer stacked system as compared with the single film. A more detailed analysis of the results together with AFM/nanoindentation measurements will be presented. This research is supported by ARO Grant W911F-08-1-0461 and NSF Grant DMR 0510138.

Tissue engineering is a field of interdisciplinary sciences being extensively researched as it is a promising and possible solution for organ transplantation. Various biomaterials and cell-seeding techniques have been developed to construct 3-D tissue in the laboratory. However, many problems of seeding cells in 3-D scaffolds pose several challengers. Thus there are numerous approaches invented with regards to handling cells directly. Our technique, bio-electrospray (BES), has been developed to be able to manipulate cells and materials simultaneously. The method was proved that it is feasible to directly jet cells at high concentration without affecting cell viability. Moreover, in this study, cell functions were investigated and presented to assure the possibility of using BES as a strategy for tissue engineering. Hence stem cells (MSC), primary cells (blood) and whole organism (C. elegans) were used to assess their associated biologics post treatment. The metabolic assay result of electrosprayed MSC have shown the same propagation efficiency along 3 days as controls. Cell viabilities, apoptosis by key enzyme assays during 24 hours after jetting and necrosis by PI staining, subsequent FACS scan after jetting, were also investigated. No significant numbers of cell deaths were investigated. Additionally, gene expressions by RT-qPCR on whole blood cells were observed by 13 specific primers to both specific and constitutive genes. Genetic level was reported as delta Ct for 78 cross comparisons. No differences of gene expression among sprayed and non-sprayed samples were observed. Finally the embryo of C. elegans were treated and examined for productivity, heat shocked response and global gene expressions. Brood size experiments have confirmed the egg laying capacity of electrosprayed samples are as efficient as the control, no GFP activation of heat shock responses as well as no significant differences in gene expressions have identified. These experiments have confirmed that BES is capable of directly handling cells for tissue engineering without perturbing viability, proliferation and gene expression. We are currently running tissue creation by using BES to position cells for controllable cell pattern