A novel γ-PGA composite gellan membrane containing glycerol for guided bone regeneration.

An ideal barrier membrane design should incorporate the function of a delivery vehicle for transporting drugs and osteoinductive factors to where the body is under inflammation. In the present study, a functional hydrogel-based barrier membrane is fabricated using calcium-form poly-γ-glutamic acid (γ-PGA) and glycerol blending into gellan gum. The concentration of the calcium-form poly-γ-glutamic acid (γ-PGA) and the glycerol ratio are studied for improving practicability in easy-handling and expanding the coverage area. Gellan gum-based membranes with uniformly distributed calcium aggregates are not only successfully manufactured but also providing excellent characteristics for protein adsorption, bioactivity, and bone cell maturation. Our composite gellan gum-based membranes were tested including to their morphology, mechanical properties, swelling behavior, protein adsorption, drug diffusion, and lysozyme degradation. The biocompatibility, proliferation, and osteoblastic response of membranes were examined by osteoblast-like (MG63) cells. Our results indicate that adequate physical cross-linking with γ-PGA improves the original mechanical properties and delays degradation. Growing glycerol ratio not only enhances the elongation at break and diffusion rate, but it also changes the tensile strength and the remaining weight. In vitro biocompatibility tests, an adequate ratio of γ-PGA modification significantly enhances the proliferation, the secretion of alkaline phosphatase (ALP) and mineralization. However, worth noting is the glycerol-modified membrane cannot bear a close resemblance with the non-glycerol group in the high level of osteoblastic response. In general, these tunable materials with biocompatibility, biodegradability, and positive osteoblastic responses were poised to be possible candidates for bone defect repair.

Tracking the Reflective Light Particles Spreading on the Cornea: An Emerging Assessment for Tear Film Homeostasis.

PURPOSE: To implement an emerging noninvasive approach for assessing the dynamic tear film (TF) homeostasis. METHODS: The video records of dynamic TF from 12 healthy orthokeratology lens wearers were obtained by a clinically available TF analyzer and decomposed as image sequences. The trajectories of TF particles were analyzed by two tracking models, the full-span model (FSM) and the fixed-duration model (FDM). FSM tracked a particle for a complete opening blink cycle, while FDM tracked 1 second of the same cycle. A power-law fitting operation [Formula: see text] was used to extract homeostasis markers based on the tracking model for each subject. RESULTS: Comparing two tracking models (N = 6), only one subject had statistical difference in averaged momentary moving speed (MMS; P = 0.0488), while none had significant difference in averaged momentary moving direction (MMD). However, both models showed good correlations in average MMS (ρ = 0.94, P = 0.0048) and MMD (ρ = 1.00, P < 0.0001) and all extracted homeostasis markers [α, ß, MMS(0.1), and MMS(2.0)]. Assessing interblink reliability in these markers under FDM tracking (N = 12), only one subject in the MMS (0.1) and another subject in the MMS (2.0) were outside 95% limits of agreement, respectively. CONCLUSIONS: FDM is a good alternative to FSM and has tracking properties of higher efficiency and easier implementation. The homeostasis markers under FDM tracking showed a good interblink consistence; therefore this approach will be a promising method for analyzing dynamic TF homeostasis in future practice. TRANSLATIONAL RELEVANCE: FDM analytical architecture can practice the past experimental platform on a TF analyzer to obtain homeostasis markers of TF.

Dual RGD-immobilized poly(L-lactic acid) by atmospheric pressure plasma jet for bone tissue engineering.

Surface treatment on PLA substrates by atmospheric pressure plasma jet (APPJ) for polymerization of dual RGD-peptides were investigated. Peptide-modified surfaces have been highlighted as the most promising approach to improve the integration of implants into surrounding bones. By varying the RF power, PLA substrates treated by APPJ process have a tendency to form a hydrophobic surface. The effects on the proliferation and differentiation of MG63 cells were evaluated and osteocalcin (OCN) expression was analyzed using RT-PCR. The water contact angle of the W/APPJ process PLA was approximately 54% of that of the W/O APPJ process PLA substrates. W/APPJ process significantly increased cell proliferation, improved the functionality of the material without using a complicated procedure. We believe that pretreatment using the APPJ processes and dual RGD grafting can be more appropriate than traditional surface modification methods, with more potential for application to bone materials.

Novel electrospun polycaprolactone/graphene oxide/Fe3O4 nanocomposites for biomedical applications.

In this study, one of the most promising methods of tailoring a composite scaffold material in nano sized diameters, electrospinning method were used to produce Polycaprolactone (PCL)/Graphene Oxide (GO)/Iron(II, III) Oxide (Fe3O4) nanocomposite fibers as biocompatible scaffolds for biomedical applications. Products were analyzed by scanning electron microscopy (SEM) for morphological analysis of the electrospun nanocomposites and Fourier Transform Infrared Spectroscopy (FTIR) was used to determine functional groups of the PCL, GO, and Fe3O4 materials in the electrospun nanocomposites. For physical properties, viscosity, density, permittivity, dielectric loss and liquid and solid state alternating current conductivity, measurements were done for each nanocomposite fibers. Effects of concentration percentage of GO on permittivity, dielectric loss and AC conductivity have been analyzed by using measured and calculated data. Trend lines have been drawn for permittivity, dielectric loss and conductivity via concentration percentage of GO. The relation between ac conductivity and frequency have been studied for each concentration percentage of GO and interpretations have been done by using the obtained results.

Osteogenesis of human adipose-derived stem cells on poly(dopamine)-coated electrospun poly(lactic acid) fiber mats.

Electrospinning is a versatile technique to generate large quantities of micro- or nano-fibers from a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized electrospun nano-fibers and use a mussel-inspired surface coating to regulate adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared poly(lactic acid) (PLA) fibers coated with polydopamine (PDA). The morphology, chemical composition, and surface properties of PDA/PLA were characterized by SEM and XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. Increased focal adhesion kinase (FAK) and collagen I levels and enhanced cell attachment and cell cycle progression were observed upon an increase in PDA content. In addition, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on a pure PLA mat. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenesis differentiation. Our results demonstrate that the bio-inspired coating synthetic degradable PLA polymer can be used as a simple technique to render the surfaces of synthetic biodegradable fibers, thus enabling them to direct the specific responses of hADSCs.

Poly(dopamine) coating of 3D printed poly(lactic acid) scaffolds for bone tissue engineering.

3D printing is a versatile technique to generate large quantities of a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized 3D printed poly(lactic acid) (PLA) scaffolds and use a mussel-inspired surface coating to regulate cell adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared PLA 3D scaffolds coated with polydopamine (PDA). The chemical composition and surface properties of PDA/PLA were characterized by XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation, and cell cycle of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. In addition, the collagen I secreted from cells was increased and promoted cell attachment and cell cycle progression were depended on the PDA content. In osteogenesis assay, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on pure PLA scaffolds. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenic differentiation. Our results demonstrate that the bio-inspired coating synthetic PLA polymer can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to direct the specific responses of hADSCs.

Clinical outcome and radiographic change of ipsilateral scapular neck and clavicular shaft fracture: comparison of operation and conservative treatment.

OBJECTIVE: The purpose of this study is to compare glenopolar angle (GPA) and the functional outcomes of fixation of both the clavicle and the scapular neck, fixation of the clavicle alone, and conservative treatment for floating-shoulder injuries. METHODS: A prospective stratified randomized study was performed in 39 adult patients who suffered floating-shoulder injuries and underwent fixation of both the clavicle and the scapular neck (group A), or fixation of the clavicle alone (group B), or conservative treatment (group C) between January 2005 and September 2011. The GPA, Disabilities of the Arm, Shoulder and Hand (DASH) score, and Constant-Murley Shoulder Outcome (Constant) score were compared between the three groups. RESULTS: All 39 patients were followed up for more than 2 years. GPA after bony consolidation was significantly better in group A than in groups B and C (p = 0.015). Functional outcomes measured by DASH and Constant scores were significantly better in group A at final follow-up (p = 0.008 and 0.002, respectively). Both DASH and Constant scores were highly correlated with GPA after consolidation (p < 0.001, respectively). The receiver operating characteristic (ROC) analysis showed that of the two randomly selected DASH scores, the smaller DASH score would have a larger GPA than the larger DASH score. Similarly, the larger Constant score would have a larger GPA than the smaller Constant score. CONCLUSIONS: Fixation of both the clavicle and the scapular neck may correct GPA and improve functional outcomes for the treatment of floating-shoulder injuries. GPA after fracture consolidation is a useful prognostic indicator of a satisfactory clinical outcome as defined by either DASH score or Constant score.

Osteogenesis of human adipose-derived stem cells on hydroxyapatite-mineralized poly(lactic acid) nanofiber sheets.

Electrospun fiber sheets with various orientations (random, partially aligned, and aligned) and smooth and roughened casted membranes were prepared. Hydroxyapatite (HA) crystals were in situ formed on these material surfaces via immersion in 10× simulated body fluid solution. The size and morphology of the resulting fibers were examined using scanning electron microscopy. The average diameter of the fibers ranged from 225±25 to 1050±150 nm depending on the electrospinning parameters. Biological experiment results show that human adipose-derived stem cells exhibit different adhesion and osteogenic differentiation on the three types of fiber. The cell proliferation and osteogenic differentiation were best on the aligned fibers. Similar results were found for phosphorylated focal adhesion kinase expression. Electrospun poly(lactic acid) aligned fibers mineralized with HA crystals provide a good environment for cell growth and osteogenic differentiation and thus have great potential in the tissue engineering field.

Using calcium silicate to regulate the physicochemical and biological properties when using ß-tricalcium phosphate as bone cement.

ß-Tricalcium phosphate (ß-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of ß-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on ß-TCP/CS composites. The results show that the apatite deposition ability of the ß-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% ß-TCP cements, respectively. In addition, the antibacterial activity of CS/ß-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the ß-TCP/CS composites. The degradation of ß-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials.

Odontogenic differentiation of human dental pulp cells by calcium silicate materials stimulating via FGFR/ERK signaling pathway.

Bone healing needs a complex interaction of growth factors that establishes an environment for efficient bone formation. We examine how calcium silicate (CS) and tricalcium phosphate (ß-TCP) cements influence the behavior of human dental pulp cells (hDPCs) through fibroblast growth factor receptor (FGFR) and active MAPK pathways, in particular ERK. The hDPCs are cultured with ß-TCP and CS, after which the cells' viability and odontogenic differentiation markers are determined by using PrestoBlue® assay and western blot, respectively. The effect of small interfering RNA (siRNA) transfection targeting FGFR was also evaluated. The results showed that CS promoted cell proliferation and enhances FGFR expression. It was also found that CS increases ERK and p38 activity in hDPCs, and furthermore, raises the expression and secretion of DSP, and DMP-1. Additionally, statistically significant differences (p<0.05) have been found in the calcium deposition in si-FGFR transfection and ERK inhibitor between CS and ß-TCP; these variations indicated that ERK/MAPK signaling is involved in the silicon-induced odontogenic differentiation of hDPCs. The current study shows that CS substrates play a key role in odontoblastic differentiation of hDPCs through FGFR and modulate ERK/MAPK activation.

The role of integrin αv in proliferation and differentiation of human dental pulp cell response to calcium silicate cement.

INTRODUCTION: It has been proved that integrin αv activity is related to cell proliferation, differentiation, migration, and organ development. However, the biological functions of integrin αv in human dental pulp cells (hDPCs) cultured on silicate-based materials have not been explored. The aim of this study was to investigate the role of integrin αv in the proliferation and odontogenic differentiation of hDPCs cultured with the effect of calcium silicate (CS) cement and ß-tricalcium phosphate (TCP) cement. METHODS: In this study, hDPCs were cultured on CS and TCP materials, and we evaluated fibronectin (FN) secretion and integrin αv expression during the cell attachment stage. After small interfering RNA transfection targeting integrin αv, the proliferation and odontogenesis differentiation behavior of hDPCs were analyzed. RESULTS: The results indicate that CS releases Si ion-increased FN secretion and adsorption, which promote cell attachment more effectively than TCP. The CS cement facilitates FN and αv subintegrin expression. However, the FN adsorption and integrin expression of TCP are similar to that observed in the control dish. Integrin αv small interfering RNA inhibited odontogenic differentiation of hDPCs with the decreased formation of mineralized nodules on CS. It also down-regulated the protein expression of multiple markers of odontogenesis and the expression of dentin sialophosphoprotein protein. CONCLUSIONS: These results establish composition-dependent differences in integrin binding and its effectiveness as a mechanism regulating cellular responses to biomaterial surface.

Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped.

ß-Tricalcium phosphate (ß-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into ß-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped ß-TCP cements. The results showed that setting time and injectability of the Si-doped ß-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into ß-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped ß-TCP cements. The degradation of ß-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped ß-TCP cements may prove to be promising bone repair materials.

Chitosan-coated electrospun PLA fibers for rapid mineralization of calcium phosphate.

In this work, hydroxyapatite (HA) mineralized on chitosan (CS)-coated poly(lactic acid) (PLA) nanofiber mat was prepared and compared in terms of mineralization characteristics. Significant calcium phosphate crystals formed on various concentrations of CS-coated PLA fiber mat with better uniformity after 2h of incubation in 10 times simulated body fluid (10× SBF). X-ray diffraction results further indicated that the composition of the deposited mineral was a mixture of dicalcium phosphate dehydrates and apatite. Chitosan, a cationic polysaccharide, can promote more nucleation and growth of calcium phosphate under conditions of 0.4% chitosan concentrations. These results indicated that HA-mineralized on CS-coated PLA fiber mat can be prepared directly via simply using CS coating followed by SBF immersion, and the results also suggest that this composite can mimic structural, compositional, and biological functions of native bone and can serve as a good candidate for bone tissue engineering (BTE).

A filter-like AuNPs@MS SERS substrate for Staphylococcus aureus detection.

An accurate, highly sensitive and rapid identification assay of cells is extremely important in areas such as medical diagnosis, biological research, and environmental monitoring. Laboratory examinations of clinical isolates require time-consuming and complex processes to identify the colony count, with approximately 10(6)-10(8) cells needed for the characterization of strains. In the present study, a highly sensitive SERS filter-like substrate is prepared with AuNPs embedded in mesoporous silica (denoted as AuNPs@MS) synthesized by a simple one-spot method, and an example of its use for the filtration and concentration of analytes from aqueous samples is reported. In an application for Staphylococcus aureus SERS discrimination, the results show that the target cells can be concentrated on the filter-like AuNPs@MS substrates within a few seconds, with much better reproducibility with regard to the SERS spectra that are obtained. The experimental findings suggest that the AuNPs@MS substrate supports much higher intensity with more distinguishable peaks compared to Au/Cr-coated substrate, and the reproducibility is also significantly improved. The substrates investigated in this study generated 900 times more SERS signals at a concentration of 10(6)CFU/mL in the detection of S. aureus on mesoporous silica (Au wt%=0) when using AuNPs@MS with 16 wt% AuNPs. The limitation of this filter-like SERS substrate can be applicable for small volume samples (few to hundred microliter).

AuNPs@mesoSiO2 composites for SERS detection of DTNB molecule.

A surface enhanced Raman spectroscopy (SERS) substrate made of gold nanoparticles-embedded mesoporous silica (AuNPs@mesoSiO2) varying with size and gold concentrations was applied for SERS applications. In this study, the AuNPs@mesoSiO2 substrate produced notable intensity and more distinguishable peaks when compared with the spectra collected directly from an Au/Cr-coated substrate with regard to the detection of a lower concentration of chemicals or environmental contamination. Both aqueous and dried coffee rings of 5-5'-Dithio-bis (2-nitrobenzoic acid) (DTNB) solutions were examined. SERS spectra obtained from the substrate showed more fingerprint peaks with significant enhancement on the spectra signals. The correlation between the SERS signal and the DTNB concentration was found to be linear within a range of 10(-2) to 10(-12) M. SERS enhancement between 25 and 8 times greater can be achieved for DTNB detection using AuNPs@mesoSiO2 compared with the normal Raman spectra obtained from the aqueous solution and the contact line of the dried coffee ring, respectively.

Differentiation between infectious and noninfectious ulcerative keratitis by Raman spectra of human teardrops: a pilot study.

PURPOSE: The aim of this study was to use Raman spectra of tears to differentiate between infectious and noninfectious ulcerative keratitis. METHODS: Raman microspectroscopy was applied using the drop-coating deposition method on Ti/Au-coated glass slides to obtain sample spectra from different human tear groups, including tears from healthy subjects and from patients with infectious and noninfectious ulcerative keratitis. By comparing the difference spectra of the groups, the authors identified local Raman features useful for differentiation of ulcerative keratitis. Principal components (PCs) of normal tears were used as affined spectral coordinates. After performing projections of Raman spectra of both infectious and noninfectious tear samples, the authors compared the two groups to identify global spectral parameters with differential statistical significance. RESULTS: Differentiation between infectious and noninfectious ulcerative keratitis might be made directly through observation of the normalized tear Raman spectra or the transformed principal scores. Spectral segments with differential statistical significance included 878∼888 cm(-1), 885∼888 cm(-1), 945∼993 cm(-1), 1007∼1015 cm(-1), 1074∼1100 cm(-1), 1090∼1094 cm(-1), 1096∼1099 cm(-1), 1386∼1403 cm(-1), 1463∼1469 cm(-1), 1469∼1473 cm(-1), 1557∼1563 cm(-1), 1584∼1588 cm(-1), and 1614∼1621 cm(-1). There were two PCs with statistically significant differences for the two groups of ulcerative keratitis, PC1 (P = 0.01) and PC2 (P = 0.05). CONCLUSIONS: This novel approach using the analysis of Raman spectra of teardrop samples for differentiation of ulcerative keratitis demonstrates the potential application of Raman microspectroscopy for clinical practice. This technology should complement the conventional cytological method for rapid diagnosis in the clinician's office.

Tear analytical model based on Raman microspectroscopy for investigation of infectious diseases of the ocular surface.

PURPOSE: To establish a tear analytical model by using Raman microspectroscopy to assess ocular surface diseases associated with infectious pathogens. METHODS: The authors applied confocal Raman microspectroscopy based on the drop-coating deposition method on Ti/Au-coated glass slides to obtain sample spectra from different types of tears, including simplified synthetic tears (SSTs), SSTs mixed with microbes, and human tears. Raman spectra were sampled by a line-mapping procedure and classified into three groups by three different zones in a dried teardrop. To determine the tear model with optimal discrimination, the spectra of the three zones were compared using spectral morphology and principal component analysis. Finally, the optimal tear model was verified by comparing the Raman spectra of human teardrops of patients with ulcerative keratitis and bacterial infection with those of patients without any identifiable infection. RESULTS: Nonhomogeneous intensities of Raman spectra collected by a line-mapping sampling procedure were found in different locations of a dried teardrop. This might have been caused by coffee-ring formation and ferny crystallization phenomena. The normalized spectra in the central zone have better discriminative potential than those in the other zones, ring zone, and transitional zone, tested by pure SSTs or SSTs with microbes. The tear model based on normalized Raman spectra in the central zone was discriminative for patients with ulcerative keratitis in the presence or absence of infection. CONCLUSIONS: Raman spectra in the central zone of a dried teardrop may serve as useful spectral fingerprints for investigating ocular surface diseases with or without infection.

TiO2 nanowire FET device: encapsulation of biomolecules by electro polymerized pyrrole propylic acid.

Silane-based methods have become the standards for the conjugation of biomolecules, especially for the preparation of one-dimensional nanomaterial biosensors. However, the specific binding of those target molecules might raise problems with regard to the sensing and non-sensing regions, which may contaminate the sensing devices and decrease their sensitivity. This paper attempts to explore the encapsulation of biomolecules on a one-dimensional nanomaterial field effect transistor (FET) biosensor using polypyrrole propylic acid (PPa). Specifically, the encapsulation of biomolecules via the electropolymerization of pyrrole propylic acid (Pa), a self-made low-conductivity polymer, on TiO(2)-nanowire (NW)-based FETs is presented. The energy dispersive spectrum (EDS) was obtained and electrical analysis was conducted to investigate PPa entrapping anti-rabbit IgG (PPa/1°Ab) on a composite film. The specificity, selectivity and sensitivity of the sensor were analyzed in order to determine the immunoreaction of PPa/1°Ab immobilized NW biosensors. Our results show that PPa/1°Ab achieved high specificity immobilization on NWs under the EDS analysis. Furthermore, the TiO(2)-NW FET immunosensor developed in this work successfully achieved specificity, selectivity and sensitivity detection for the target protein rabbit IgG at the nano-gram level. The combination of PPa material and the electropolymerization method may provide an alternative method to immobilize biomolecules on a specific surface, such as NWs.

A dielectrophoretic chip with a roughened metal surface for on-chip surface-enhanced Raman scattering analysis of bacteria.

We present an analysis of the results of in situ surface-enhanced Raman scattering (SERS) of bacteria using a microfluidic chip capable of continuously sorting and concentrating bacteria via three-dimensional dielectrophoresis (DEP). Microchannels were made by sandwiching DEP microelectrodes between two glass slides. Avoiding the use of a metal nanoparticle suspension, a roughened metal surface is integrated into the DEP-based microfluidic chip for on-chip SERS detection of bacteria. On the upper surface of the slide, a roughened metal shelter was settled in front of the DEP concentrator to enhance Raman scattering. Similarly, an electrode-patterned bottom layer fabricated on a thin cover-slip was used to reduce fluorescence noise from the glass substrate. Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) bacteria were effectively distinguished in the SERS spectral data. Staphylococcus aureus (concentration of 10(6) CFUml) was continuously separated and concentrated via DEP out of a sample of blood cells. At a flow rate of 1 mulmin, the bacteria were highly concentrated at the roughened surface and ready for on-chip SERS analysis within 3 min. The SERS data were successfully amplified by one order of magnitude and analyzed within a few minutes, resulting in the detection of signature peaks of the respective bacteria.

Stroke rehabilitation: strategies to enhance motor recovery.

Recent evidence indicates that the brain can remodel after stroke, primarily through synaptogenesis. Task-specific and repetitive exercise appear to be key factors in promoting synaptogenesis and are central elements in rehabilitation of motor weakness following stroke. Expert medical management ensures a patient is well enough to participate in rehabilitation with minimal distractions due to pain or depression. Contraint-induced motor therapy and body-weight-supported ambulation are forms of exercise that "force use" of an impaired upper extremity. Technologies now in common use include robotics, functional electrical stimulation, and, to a lesser degree, transcranial magnetic stimulation and virtual reality. The data on pharmacological interventions are mixed but encouraging; it is hoped such treatments will directly stimulate brain tissue to recovery. Mitigation of factors preventing movement, such as spasticity, might also play a role. Research evaluating these motor recovery strategies finds them generally good at the movement level but somewhat less robust when looking at functional performance. It remains unclear whether inconsistent evidence for functional improvement is a matter of poor treatment efficacy or insensitive outcome measures.