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Giri S, Braumann UD, Giri P, et al. Int J Nanomedicine. 2013;8(1):1525–1539. The Editor and Publisher of International Journal of Nanomedicine wish to retract the published article. Concerns were raised regarding the duplication of 30 d and 90 d hepatocyte images shown in Figure 3A. The corresponding author did respond to our queries and did provide some data relating to Figure 3A. However, the author was unable to adequately explain why the images had been duplicated and the provided data showed inconsistencies and was not satisfactory. The decision was made to retract the paper and the authors were notified of this. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”. This retraction relates to this paper

Transforming growth factor beta 3 (TGF&beta, 3) promotes tenogenic differentiation and may enhance tendon regeneration in vivo. This study aimed to apply TGF&beta, 3 absorbed in decellularized equine superficial digital flexor tendon scaffolds, and to investigate the bioactivity of scaffold-associated TGF&beta, 3 in an in vitro model. TGF&beta, 3 could effectively be loaded onto tendon scaffolds so that at least 88% of the applied TGF&beta, 3 were not detected in the rinsing fluid of the TGF&beta, 3-loaded scaffolds. Equine adipose tissue-derived multipotent mesenchymal stromal cells (MSC) were then seeded on scaffolds loaded with 300 ng TGF&beta, 3 to assess its bioactivity. Both scaffold-associated TGF&beta, 3 and TGF&beta, 3 dissolved in the cell culture medium, the latter serving as control group, promoted elongation of cell shapes and scaffold contraction (p &lt, 0.05). Furthermore, scaffold-associated and dissolved TGF&beta, 3 affected MSC musculoskeletal gene expression in a similar manner, with an upregulation of tenascin c and downregulation of other matrix molecules, most markedly decorin (p &lt, 0.05). These results demonstrate that the bioactivity of scaffold-associated TGF&beta, 3 is preserved, thus TGF&beta, 3 application via absorption in decellularized tendon scaffolds is a feasible approach.

The advance of optical coherence tomography (OCT) enables a detailed examination of the human retina in-vivo for clinical routine and experimental eye research. Only few investigations to date captured human foveal morphology in a large subject group on the basis of a detailed analysis employing mathematical models. However, even for important foveal characteristics unified terminology and clear definitions were not implemented so far. This might be a reason, why to this day the human fovea is considered to be a mostly symmetric and round structure. Therefore, the most important finding of this work is the detailed analysis of the asymmetric structure of the human fovea. We employed five clinically highly relevant foveal characteristics, which are derived from a previously published fovea model. For each, an accurate mathematical description is given. The presented properties include (1) mean retinal thickness inside a defined radius, (2) foveal bowl area, (3) a new, exact definition of foveal radius, (4) maximum foveal slope, and (5) the maximum height of the foveal rim. Furthermore, minimum retinal thickness was derived and analyzed. 220 strictly controlled healthy Caucasian subjects of European decent with an even distribution of age and gender were imaged with an Heidelberg Spectralis OCT. Detailed analysis demonstrated the following general results: (1) significant gender difference regarding the central foveal subfield thickness (CFST) but no significant differences for the minimum central retinal thickness, (2) a strong correlation between right and left eye of the same subject, and, as essential finding, (3) strong structural differences of the fovea form in the different anatomical directions (nasal, temporal, inferior and superior). In the analysis of the foveal asymmetry, it will be demonstrated that the foveal radius is larger in nasal and temporal direction compared to inferior and superior position. Furthermore, it will be shown that the circular fovea rather has an elliptic form with the larger axis along the nasal to temporal direction. Interestingly, the foveal slope shows a divergent behavior as the temporal direction has the smallest slope angle and both, inferior and superior angles are clearly larger than the others. The findings in this work can be used for an exact quantification of changes in early stages of various retinal diseases and as a marker for initial diagnosis.

Transplantation of multipotent mesenchymal progenitor cells is a valuable option for treating tendon disease. Tenogenic differentiation leading to cell replacement and subsequent matrix modulation may contribute to the regenerative effects of these cells, but it is unclear whether this occurs in the inflammatory environment of acute tendon disease. Equine adipose-derived stromal cells (ASC) were cultured as monolayers or on decellularized tendon scaffolds in static or dynamic conditions, the latter represented by cyclic stretching. The impact of different inflammatory conditions, as represented by supplementation with interleukin-1&beta, and/or tumor necrosis factor-&alpha, or by co-culture with allogeneic peripheral blood leukocytes, on ASC functional properties was investigated. High cytokine concentrations increased ASC proliferation and osteogenic differentiation, but decreased chondrogenic differentiation and ASC viability in scaffold culture, as well as tendon scaffold repopulation, and strongly influenced musculoskeletal gene expression. Effects regarding the latter differed between the monolayer and scaffold cultures. Leukocytes rather decreased ASC proliferation, but had similar effects on viability and musculoskeletal gene expression. This included decreased expression of the tenogenic transcription factor scleraxis by an inflammatory environment throughout culture conditions. The data demonstrate that ASC tenogenic properties are compromised in an inflammatory environment, with relevance to their possible mechanisms of action in acute tendon disease.

A fovea, the retinal pitted invagination in the area centralis, is found in many vertebrates such as fish, reptiles, birds and in higher primates including humans. Because of the refractive index step between the retinal tissue and vitreous, the fovea defines an optically effective interface with aspherical characteristics, which influences the ray propagation to the receptor layer buried about 250 μm within the retinal layers [1]. In principle, two basic foveal shapes can be distinguished [2]. On the one hand, the convexiclivate type of fovea is a deep, funnel-shaped depression with a convex slope of the side walls and is observed in birds, some lizards, and certain deep-sea teleosts. On the other hand, the concaviclivate type of fovea is shallow and gradually shaped; the human fovea is of this type. Previous examinations on the influence of the fovea on the image-forming process have mainly been focused on the steep foveae types in which increasing magnification and directional-dependent distortion effects were predicted [3], [4], [5], [6], [7]. These investigations have been restricted to simple geometrical descriptions of the foveal shape, such as spheres and paraboloids. Real geometrical foveal structures from living creatures have not yet been examined. Moreover, the ray-trace considerations have been partly reduced to a few selected rays approaching the vitreo-retinal interface, and very limited numbers of incidence directions and wavelength-dependent effects have been investigated. Studies on the refracting characteristics of human foveae types are even more rare [2], [8]. C. Ross analyzed the optical functionality of the foveae of tarsiers, neglecting the influence of the anterior part of the eye and regarding only position shifts of three single rays. This contribution aims to answer the question on whether a comprehensive human eye model, which takes all optical components and their aberrations into account, leads to more detailed findings. In particular, field- and wavelength-dependent influences on spot sizes and positions, based on actual ray-bundle-cones are considered, which allow the estimation of aberration effects. With the current investigation, we address this issue by combining a realistic anatomical model of the anterior parts of the eye with real human fovea geometries. For the anterior eye, the human eye model of Liou and Brennan [9], with a gradient index profile of the crystalline lens, was used. To investigate the influence of actual fovea geometries on image formation, two selected and different foveal shapes (average and extraordinary), based on in vivo optical coherence tomography (OCT) measurements of a human eye were used. We analyzed the ray-optical behavior and implemented additional considerations that involve the variation of the observed field position, pupil diameter, chromatic effects, and especially the imaging behavior of peripheral colors in the receptor plane when the primary color is focused on this theoretical surface. These simulations validate and expand the knowledge about the correlation between aperture size and real and theoretical spot size, the effect of the foveal shape on either spot size and axial spot position, and, finally, the lateral spot position and color dependency of the incident angle.

This paper deals with pattern formation in Langmuir monolayers of two sets of lipid mixtures that include (1) a fluorinated lipid for phase separation, (2) a polymerizable lipid for stabilization of the patterned structure, and (3) a unit for the presentation of biological recognition units. Differences in the distribution of these functionalities allow a polymerization of dispersed or continuous phase and a placement of the recognition units in crystalline or solid analogue phase. Also, a ternary mixture including a lipid modified with the tandem repeat domain of MUC1 plus a TN-antigen was studied. Based on the biphasic pattern obtained (starlike crystals of up to 50 μm with a fine structure of some micrometers), we also verified the potential of the laterally patterned monolayer to stimulate the immune system (quartz crystal microbalance). The second set of lipids combines a highly fluorinated itaconic ester (polymerizable unit) with the natural phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine.

As revealed by optical coherence tomography (OCT), the shape of the fovea may vary greatly among individuals. However, none of the hitherto available mathematical descriptions comprehensively reproduces all individual characteristics such as foveal depth, slope, naso-temporal asymmetry, and others. Here, a novel mathematical approach is presented to obtain a very accurate model of the complete 3D foveal surface of an individual, by utilizing recent developments in OCT. For this purpose, a new formula was developed serving as a simple but very flexible way to represent a given fovea. An extensive description of the used model parameters, as well as, of the complete method of reconstructing a foveal surface from OCT data, is presented. Noteworthy, the formula analytically provides characteristic foveal parameters and thus allows for extensive quantification. The present approach was verified on 432 OCT scans and has proved to be able to capture the whole range of asymmetric foveal shapes with high accuracy (i.e. a mean fit error of 1.40 μm).

Drug addiction is a chronic, relapsing disease caused by neurochemical and molecular changes in the brain. In this human autopsy study qualitative and quantitative changes of glial fibrillary acidic protein (GFAP)-positive astrocytes in the hippocampus of 26 lethally intoxicated drug addicts and 35 matched controls are described. The morphological characterization of these cells reflected alterations representative for astrogliosis. But, neither quantification of GFAP-positive cells nor the Western blot analysis indicated statistical significant differences between drug fatalities versus controls. However, by semi-quantitative scoring a significant shift towards higher numbers of activated astrocytes in the drug group was detected. To assess morphological changes quantitatively, graph-based representations of astrocyte morphology were obtained from single cell images captured by confocal laser scanning microscopy. Their underlying structures were used to quantify changes in astroglial fibers in an automated fashion. This morphometric analysis yielded significant differences between the investigated groups for four different measures of fiber characteristics (Euclidean distance, graph distance, number of graph elements, fiber skeleton distance), indicating that, e.g., astrocytes in drug addicts on average exhibit significant elongation of fiber structures as well as two-fold increase in GFAP-positive fibers as compared with those in controls. In conclusion, the present data show characteristic differences in morphology of hippocampal astrocytes in drug addicts versus controls and further supports the involvement of astrocytes in human pathophysiology of drug addiction. The automated quantification of astrocyte morphologies provides a novel, testable way to assess the fiber structures in a quantitative manner as opposed to standard, qualitative descriptions.

A novel method for the automated detection of the outer choroid boundary within spectral-domain optical coherence tomography image data, based on an image model within the space of functions of bounded variation and the application of quadratic measure filters, is presented. The same method is used for the segmentation of retinal layer boundaries and proves to be suitable even for data generated without special imaging modes and moderate line averaging. Based on the segmentations, an automated determination of the central fovea region and choroidal thickness measurements for this and two adjacent 1-mm regions are provided. The quality of the method is assessed by comparison with manual delineations performed by five trained graders. The study is based on data from 50 children of the ages 8 to 13 that were obtained in the framework of the LIFE Child study at Leipzig University.

This paper describes the phase separating behavior of Langmuir monolayers from mixtures of different lipids that (i) either carry already a glycopeptide recognition site or can be easily modified to carry one and (ii) polymerizable lipids. To ensure demixing during compression, we used fluorinated lipids for the biological headgroups and hydrocarbon based lipids as polymerizable lipids. As a representative for a lipid monomer, which can be polymerized in the hydrophilic headgroup, a methacrylic monomer was used. As a monomer, which can be polymerized in the hydrophobic tail, a lipid with a diacetylene unit was used (pentacosadiynoic acid, PDA). The fluorinated lipids were on the one hand a perfluorinated lipid with three chains and on the other hand a partially fluorinated lipid with a T(N)-antigen headgroup. The macroscopic phase separation was observed by Brewster angle microscopy, whereas the phase separation on the nanoscale level was observed by atomic force microscopy. It turned out that all lipid mixtures showed (at least) a partial miscibility of the hydrocarbon compounds in the fluorinated compounds. This is positive for pattern formation, as it allows the formation of small demixed 2D patterned structures during crystallization from the homogeneous phase. For miscibility especially a liquid analogue phase proved to be advantageous. As lipid 3 with three fluorinated lipid chains (very stable monolayer) is miscible with the polymerizable lipids 1 and 2, it was mostly used for further investigations. For all three lipid mixtures, a phase separation on both the micrometer and the nanometer level was observed. The size of the crystalline domains could be controlled not only by varying the surface pressure but also by varying the molar composition of the mixtures. Furthermore, we showed that the binary mixture can be stabilized via UV polymerization. After polymerization and subsequent expansion of the barriers, the locked-in polymerized structures are stable even at low surface pressures (10 mN/m), where the unpolymerized mixture did not show any segregation.

State-of-the-art image-processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudocolored images of different wavelengths, provided that multispectral images are recorded to compensate for any motion-related artefacts that occur during examination. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The corneal subbasal nerve plexus (SNP) offers high potential for early diagnosis of diabetic peripheral neuropathy. Changes in subbasal nerve fibers can be assessed in vivo by confocal laser scanning microscopy (CLSM) and quantified using specific parameters. While current study results agree regarding parameter tendency, there are considerable differences in terms of absolute values. The present study set out to identify factors that might account for this high parameter variability.In three healthy subjects, we used a novel method of software-based large-scale reconstruction that provided SNP images of the central cornea, decomposed the image areas into all possible image sections corresponding to the size of a single conventional CLSM image (0.16 mm2), and calculated a set of parameters for each image section. In order to carry out a large number of virtual examinations within the reconstructed image areas, an extensive simulation procedure (10,000 runs per image) was implemented.The three analyzed images ranged in size from 3.75 mm2 to 4.27 mm2. The spatial configuration of the subbasal nerve fiber networks varied greatly across the cornea and thus caused heavily location-dependent results as well as wide value ranges for the parameters assessed. Distributions of SNP parameter values varied greatly between the three images and showed significant differences between all images for every parameter calculated (p 0.001 in each case).The relatively small size of the conventionally evaluated SNP area is a contributory factor in high SNP parameter variability. Averaging of parameter values based on multiple CLSM frames does not necessarily result in good approximations of the respective reference values of the whole image area. This illustrates the potential for examiner bias when selecting SNP images in the central corneal area.

Basal cell carcinoma (BCC) is the most common malignant skin cancer. For a deeper insight into the specific growth patterns of the tumorous tissue in BCC, we have focused on the development of a novel automated image-processing chain for 3D reconstruction of BCC using histopathological serial sections. For fully automatic delineation of the tumor within the tissue, we apply a fuzzy c-means segmentation method. We used a novel multi-grid form of the non-linear registration introduced by Braumann and Kuska in 2005 effectively suppressing registration runs into local minima (possibly caused by diffuse nature of the tumor). Our method was successfully applied in a proof-of-principle study for automated reconstruction.

Das prazise Segmentieren von Knochen in klinischen CT-Aufnahmen spielt heutzutage eine wichtige Rolle. Vor allem, um operative Eingriffe zu planen oder das masgeschneiderte Anfertigen von Implantaten zu ermoglichen, ist eine Erkennung auch feiner Knochendetails unabdingbar. Gerade die feinen, lamellenartigen Strukturen im Nasenbereich konnen bei CT-Aufnahmen, die in der klinischen Routine angefertigt werden, durch ihre zu geringe Signalstarke oft nicht als Knochen identifiziert werden. Um diese, vom sogenannten Partialvolumeneffekt betroffenen Strukturen dennoch automatisch segmentieren zu konnen, stellen wir hier eine Methode vor, die ausgehend von einer Initial-korrekten, aber unzureichenden Segmentierung, iterativ angrenzende, schwache Strukturen erkennt. Dabei wird fur Voxel, die am Rande des segmentierten Knochens als Hintergrund erkannt wurden, lokal die Wahrscheinlichkeit geschatzt, eine knocherne Struktur zu reprasentieren. Mit dieser Reevaluierung wird die bestehende Segmentierung so lange iterativ erweitert, bis sich eine Konvergenz einstellt. Durch den lokalen Charakter der Randvoxel-Neubewertung kann der vorgestellte Algorithmus ausgezeichnet parallel implementiert werden.

Prostate cancer is routinely graded according to the Gleason grading scheme. This scheme is predominantly based on the textural appearance of aberrant glandular structures. Gleason grade is difficult to standardize and often leads to discussion due to interrater and intrarater disagreement. Thus, we investigated whether digital image based automated quantitative histomorphometry could be used to achieve a more standardized, reproducible classification outcome.In a proof of principle study we developed a method to evaluate digitized histological images of single prostate cancer regions in hematoxylin and eosin stained sections. Preprocessed color images were subjected to color deconvolution, followed by the binarization of obtained hematoxylin related image channels. Highlighted neoplastic epithelial gland related objects were morphometrically assessed by a classifier based on 2 calculated quantitative and objective geometric measures, that is inverse solidity and inverse compactness. The procedure was then applied to the prostate cancer probes of 125 patients. Each probe was independently classified for Gleason grade 3, 4 or 5 by an experienced pathologist blinded to image analysis outcome.Together inverse compactness and inverse solidity were adequate discriminatory features for a powerful classifier that distinguished Gleason grade 3 from grade 4/5 histology. The classifier was robust on sensitivity analysis.Results suggest that quantitative and interpretable measures can be obtained from image based analysis, permitting algorithmic differentiation of prostate Gleason grades. The method must be validated in a large independent series of specimens.

Basal cell carcinoma (BCC) is the most common malignant skin cancer. For a deeper insight into the specific growth patterns of the tumorous tissue in BCC, we have focused on the development of a novel automated image-processing chain for 3D reconstruction of BCC using histopathological serial sections. For fully automatic delineation of the tumor within the tissue, we apply a fuzzy c-means segmentation method. We used a novel multi-grid form of the non-linear registration introduced by Braumann and Kuska in 2005 effectively suppressing registration runs into local minima (possibly caused by diffuse nature of the tumor). Our method was successfully applied in a proof-of-principle study for automated reconstruction.

Membranes based on functional biocompatible polymers can be regarded as a useful model system to study biological interactions, e.g. antibody-antigen interactions or protein polymer interactions. These model systems may give a better insight into these processes and may help to find suitable polymeric structures offering biocompatibility as well as reduced polymer protein interaction. In this respect, Langmuir-Blodgett (LB) layer formation at the air/water (A/W) interface is studied in respect to polymer architecture in this article. For this purpose, narrowly distributed N-(2-hydroxypropyl)-methacrylamide (HPMA) random and block copolymers have been prepared by the RAFT polymerization method. For random copolymers different molecular weights were prepared. As for the block copolymers also the ratio of hydrophilic and hydrophobic units was varied in order to study the influence of hydrophobic block length on collapse pressure and area. The molecular weights of all polymers were around 15 kDa and 30 kDa. In the case of block copolymers we found a direct correlation of the length of the hydrophobic block to the collapse area. Furthermore, hysteresis experiments clearly point out that block copolymers form stable LB layers. No remarkable changes in collapse pressure or area could be observed. In contrast the area occupied by random copolymers changes at each hysteresis cycle indicating a loss of polymer to the aqueous subphase. In addition the LB layers were transferred onto mica substrates. The block copolymers formed stable and defect free membranes over an area of 100 microm(2) with a roughness (rms) 1.3-1.4 A. On the contrary, membranes based on random copolymers turned out to have a higher surface roughness. Our findings clearly underline the influence of polymer structure on the LB layer formation at the A/W interface.

State-of-the-art image processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudo-coloured images of different wavelengths, provided that multispectral images are recorded to compensate for any motion related artefacts which occur during examination.

One important application of image processing in medicine is to register tissue samples onto another. Registering these highly textured images with non-parametric methods sometimes leads to solutions which are known to be suboptimal. We show a projection technique for unwanted vortices in the displacement field. A new strategy is presented which does not change the registration method itself but continuously correct the solution during the registration process.

We present polymeric MEMS materials which reversibly respond to either thermal or UV stimuli by moving between nearly flat (r ∼ ∞) and tightly curled states (r ∼ 5mm) with variations in the radiation environment or temperature. The molecular orientation gradient of a liquid crystal network controls the primary bending axes, while controlled order parameter variations are responsible for the degree of deformation. In the case of thermal activation, these order changes are dominated by thermal motion, while UV-switchable defects bring about reduced network order in the case of UV actuation. We report fabrication and operation of the actuators and supplementary data regarding alignment configurations for controllable deformations, the phase behaviour of the liquid crystal constituents, thermal expansions, and absorption of the UV dyes are included. We find that splayed molecular configurations are preferred over twisted modes due to their single deformation axis, and that the optimum concentration of active molecules for UV-driven actuation is on the order of 7-8wt.%.

Shibashish Giri,1 Ulf-Dietrich Braumann,2,3 Priya Giri,1,3 Ali Acikgöz,1,4 Patrick Scheibe,3,5 Karen Nieber,6 Augustinus Bader1 1Department of Cell Techniques and Applied Stem Cell Biology, Center for Biotechnology and Biomedicine (BBZ), 2Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), University of Leipzig, Leipzig, Germany; 3Interdisciplinary Center for Bioinformatics (IZBI), University of Leipzig, Leipzig, Germany; 4Klinikum St Georg, Leipzig, Germany; 5Translational Center for Regenerative Medicine (TRM Leipzig), 6Department of Pharmacology for Natural Sciences, Institute of Pharmacy, University of Leipzig, Leipzig, Germany Abstract: Much effort has been directed towards the optimization of the capture of in vivo hepatocytes from their microenvironment. Some methods of capture include an ex vivo cellular model in a bioreactor based liver module, a micropatterned module, a microfluidic 3D chip, coated plates, and other innovative approaches for the functional maintenance of primary hepatocytes. However, none of the above methods meet US Food and Drug Administration (FDA) guidelines, which recommend and encourage that the duration of a toxicity assay of a drug should be a minimum of 14 days, to a maximum of 90 days for a general toxicity assay. Existing innovative reports have used undefined extracellular matrices like matrigel, rigid collagen, or serum supplementations, which are often problematic, unacceptable in preclinical and clinical applications, and can even interfere with experimental outcomes. We have overcome these challenges by using integrated nanostructured self-assembling peptides and a special combination of growth factors and cytokines to establish a proof of concept to mimic the in vivo hepatocyte microenvironment pattern in vitro for predicting the in vivo drug hepatotoxicity in a scalable bioartificial liver module. Hepatocyte functionality (albumin, urea) was measured at days 10, 30, 60, and 90 and we observed stable albumin secretion and urea function throughout the culture period. In parallel, drug metabolizing enzyme biomarkers such as ethoxyresorufin-O-deethylase, the methylthiazol tetrazolium test, and the lactate dehydrogenase test were carried out at days 10, 30, 60, and 90. We noticed excellent mitochondrial status and membrane stability at 90 days of culture. Since alpha glutathione S-transferase (GST) is highly sensitive and a specific marker of hepatocyte injury, we observed significantly low alpha GST levels on all measured days (10, 30, 60, and 90). Finally, we performed the image analysis of mitochondria-cultured hepatocytes at day 90 in different biophysical parameters using confocal microscopy. We applied an automatic algorithm-based method for 3D visualization to show the classic representation of the mitochondrial distribution in double hepatocytes. An automated morphological measurement was conducted on the mitochondrial distribution in the cultured hepatocytes. Our proof of concept of a scalable bioartificial liver modular device meets FDA guidelines and may function as an alternative model of animal experimentation for pharmacological and toxicological studies involving drug metabolism, enzyme induction, transplantation, viral hepatitis, hepatocyte regeneration, and can also be used in other existing bioreactor modules for long-term culture for up to 90 days or more. Keywords: image analysis, 3D visualization, bioreactor, FDA guidelines, primary hepatocytes, hepatotoxicity

Well-defined gradients in molecular alignment have been used as tools to generate large amplitude, light-induced deformations in stiff polymer networks. These systems are reversible, monolithic and based on a simple one-step self-assembly process. To fabricate the actuators, diacrylate dopants containing azobenzene moieties were blended with liquid crystalline diacrylate hosts and photopolymerized in a twisted configuration. The resulting twisted networks were heavily crosslinked with room temperature elastic moduli on the order of 1 GPa. Regardless of the temperature with respect to the glass transitions, subsequent exposure to UV radiation induced anisotropic expansion/contraction, and simple variations in geometry were used to generate uniaxial bending or helical coiling deformation modes. Because mechanical energy is directly related to elastic modulus, these systems are expected to provide significantly greater work output than contemporary polymer actuator materials. © The Royal Society of Chemistry 2005.