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Artificial organs are playing an increasingly important role in medical field. Artificial anal sphincter, as an example, is a widely used medical device for fecal incontinence. Though it could help patients maintain continence, the issue of perception reconstruction is still unsolved, which means that patients cannot control defecation as desired.In this paper, a novel sensor system based on vector similarity has been analyzed and evaluated. The sensor system is a self-packaged strain gauge sensor with a small size 14.5 mm × 6 mm, especially for medical device implanted in body to reconstruct perception function. In order to overcome the disadvantages of single threshold judgment, a more accurate and reliable judgment standard for content pressure detection in rectum is developed by using vector similarity method. Therefore, in the novel sensor system, standard multi-parameters are comprehensive considered. Furthermore, weight-optimization of sensors are investigated since each sensor has played a different role in detection. Finally, sensor calibration, in vitro and in vivo experiments are established.In sensor calibration, the result RAll of these have proven that the novel perception reconstruction module with sensor system based on vector similarity is more acceptable and reliable.

The increasing prevalence of chronic lung disease worldwide, combined with the emergence of multiple pandemics arising from respiratory viruses over the past century, highlights the need for safer and efficacious means for providing artificial lung support. Mechanical ventilation is currently used for the vast majority of patients suffering from acute and chronic lung failure, but risks further injury or infection to the patient's already compromised lung function. Extracorporeal membrane oxygenation (ECMO) has emerged as a means of providing direct gas exchange with the blood, but limited access to the technology and the complexity of the blood circuit have prevented the broader expansion of its use. A promising avenue toward simplifying and minimizing complications arising from the blood circuit, microfluidics-based artificial organ support, has emerged over the past decade as an opportunity to overcome many of the fundamental limitations of the current standard for ECMO cartridges, hollow fiber membrane oxygenators. The power of microfluidics technology for this application stems from its ability to recapitulate key aspects of physiological microcirculation, including the small dimensions of blood vessel structures and gas transfer membranes. An even greater advantage of microfluidics, the ability to configure blood flow patterns that mimic the smooth, branching nature of vascular networks, holds the potential to reduce the incidence of clotting and bleeding and to minimize reliance on anticoagulants. Here, we summarize recent progress and address future directions and goals for this potentially transformative approach to artificial lung support.

Extreme prematurity, defined as a gestational age of fewer than 28weeks, is a significant health problem worldwide. It carries a high burden of mortality and morbidity, in large part due to the immaturity of the lungs at this stage of development. The standard of care for these patients includes support with mechanical ventilation, which exacerbates lung pathology. Extracorporeal life support (ECLS), also called artificial placenta technology when applied to extremely preterm (EPT) infants, offers an intriguing solution. ECLS involves providing gas exchange via an extracorporeal device, thereby doing the work of the lungs and allowing them to develop without being subjected to injurious mechanical ventilation. While ECLS has been successfully used in respiratory failure in full-term neonates, children, and adults, it has not been applied effectively to the EPT patient population. In this review, we discuss the unique aspects of EPT infants and the challenges of applying ECLS to these patients. In addition, we review recent progress in artificial placenta technology development. We then offer analysis on design considerations for successful engineering of a membrane oxygenator for an artificial placenta circuit. Finally, we examine next-generation oxygenators that might advance the development of artificial placenta devices.

Extreme prematurity remains a major cause of neonatal mortality and severe long-term morbidity. Current neonatal care is associated with significant morbidity due to iatrogenic injury and developmental immaturity of extreme premature infants. A more physiologic approach, replacing placental function and providing a womb-like environment, is the foundational principle of artificial placenta (AP) and womb (AW) technology. The concept has been studied during the past 60 years with limited success. However, recent technological advancements and a greater emphasis on mimicking utero-placental physiology have improved the success of experimental models, bringing the technology closer to clinical translation. Here, we review the rationale for and history of AP and AW technology, discuss the challenges that needed to be overcome, and compare recent successful models. We conclude by outlining some remaining challenges to be addressed on the path towards clinical translation and opportunities for future research.

In this Editor's Review, articles published in 2018 are organized by category and summarized. We provide a brief reflection of the research and progress in artificial organs intended to advance and better human life while providing insight for continued application of these technologies and methods. Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. Peer-reviewed special issues this year included contributions from the 13th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Undar, and the 25th Congress of the International Society for Mechanical Circulatory Support edited by Dr. Marvin Slepian. Additionally, many editorials highlighted the worldwide survival differences in hemodialysis and perspectives on mechanical circulatory support and stem cell therapies for cardiac support. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.

Organ-on-a-chip platforms have recently seen tremendous progress. They have found potential applications in the study of physiology and pathology of tissues, drug toxicity, and development of tissue models for replacement of animal studies. However, their potential role in organ transplantation has hardly been discussed, so far. Organ transplantation represents a major medical advancement of the twenty-first century, yet it suffers from limitation due to the shortage of organ supply. Very often, organs harvested from donor's body are deemed non-usable because of being damaged or "marginal". Recently, developments of bioartificial devices such as artificial placenta and renal assist-devices have shown that it is possible to develop novel bioartificial organ support systems that can support the healing of damaged or marginal organs prior to their transplantation. In the current article, we introduce a novel concept for building bioartificial organ assist devices and systems by integrating arrays of numerous organ-on-a-chip platforms. The new system can be used in organ repair centers as means for temporary organ support and functional enhancement. We have also briefly reviewed the relevant organ-on-a-chip platforms developed so far, and related literature to form a basis for developing our new concept, device and its application. The proposed system may help to increase the number of organs available for transplantation and improve transplantation outcomes. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2006-2018, 2019.

While fecal incontinence (FI) is not fatal, it can dramatically decrease the patient's quality of life. An artificial anal sphincter (AAS) is an implantable device that treats FI by replacing a diseased or damaged anal sphincter, thus allowing the patient's continence to be maintained. Here, we report a novel implantable puborectalis-like artificial anal sphincter (PAAS) that replicates rectal perception and has a low risk of ischemia necrosis. Using the pressure sensors embedded in the PAAS, the relationship between the mass of feces and the pressure was determined, and a feces mass estimation model was developed based on in vitro studies. Rectal perception is provided through the real-time monitoring of rectal feces, and the feeling of defecation is quantified based on a comparison between the feces mass and a preset threshold mass. In vivo studies were performed for validation, and the accuracy of the model was determined to be as high as 90%. The performance of the PAAS in the real-time monitoring of rectal feces and its in vivo biocompatibility were also evaluated. The device should further the functionality of existing AAS systems while improving their biosafety and thus expand the applicability of implantable AAS systems in the treatment of FI.

The advancement and improvement in decellularization methods can be attributed to the increasing demand for tissues and organs for transplantation. Decellularized tissues and organs, which are free of cells and genetic materials while retaining the complex ultrastructure of the extracellular matrix (ECM), can serve as scaffolds to subsequently embed cells for transplantation. They have the potential to mimic the native physiology of the targeted anatomic site. ECM from different tissues and organs harvested from various sources have been applied. Many techniques are currently involved in the decellularization process, which come along with their own advantages and disadvantages. This review focuses on recent developments in decellularization methods, the importance and nature of detergents used for decellularization, as well as on the role of the ECM either as merely a physical support or as a scaffold in retaining and providing cues for cell survival, differentiation and homeostasis. In addition, application, status, and perspectives on commercialization of bioproducts derived from decellularized tissues and organs are addressed. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1494-1505, 2018.

Pancreatic-islet transplantation is a safe and noninvasive therapy for type 1 diabetes. However, the currently applied site for transplantation, ie, the liver, is not the optimal site for islet survival. Because the human body has shortcomings in providing an optimal site, artificial transplantation sites have been proposed. Such an artificial site could consist of a polymeric scaffold that mimics the pancreatic microenvironment and supports islet function. Recently, remarkable progress has been made in the technology of engineering scaffolds. The polymer-islet interactions, the site of implantation, and scaffold prevascularization are critical factors for success or failure of the scaffolds. This article critically reviews these factors while also discussing translation of experimental studies to human application as well as the steps required to create a clinically applicable prevascularized, retrievable scaffold for implantation of insulin-producing cells for treatment of type 1 diabetes mellitus.Important advances have been made in the design and testing of polymeric scaffolds for pancreatic islet transplantation, but some challenges remain to be solved before human application.

One of the major challenges in modern robotics is controlling micromanipulation by active and adaptive materials. In the respiratory system, such actuation enables pathogen clearance by means of motile cilia. While various types of artificial cilia have been engineered recently, they often involve complex manufacturing protocols and focus on transporting liquids only. Here, soft magnetic carpets are created via an easy self-assembly route based on the Rosensweig instability. These carpets can transport not only liquids but also solid objects that are larger and heavier than the artificial cilia, using a crowd-surfing effect.This amphibious transportation is locally and reconfigurably tunable by simple micromagnets or advanced programmable magnetic fields with a high degree of spatial resolution. Two surprising cargo reversal effects are identified and modeled due to collective ciliary motion and nontrivial elastohydrodynamics. While the active carpets are generally applicable to integrated control systems for transport, mixing, and sorting, these effects can also be exploited for microfluidic viscosimetry and elastometry., Advanced Science, 8 (21), ISSN:2198-3844

One day soon it may be possible to replace a failing heart, liver, or kidney with a long-lasting mechanical replacement or perhaps even with a 3-D printed version based on the patient's own tissue. Such artificial organs could make transplant waiting lists and immunosuppression a thing of the past. Supposing that this happens, what will the ongoing care of people with these implants involve? In particular, how will the need to maintain the functioning of artificial organs over an extended period affect patients and their doctors and the responsibilities of those who manufacture such devices? Drawing on lessons from the history of the cardiac pacemaker, this article offers an initial survey of the ethical issues posed by the need to maintain and service artificial organs. We briefly outline the nature and history of cardiac pacemakers, with a particular focus on the need for technical support, maintenance, and replacement of these devices. Drawing on the existing medical literature and on our conversations and correspondence with cardiologists, regulators, and manufacturers, we describe five sources of ethical issues associated with pacemaker maintenance: the location of the devices inside the human body, such that maintenance generates surgical risks; the complexity of the devices, which increases the risk of harms to patients as well as introducing potential injustices in access to treatment; the role of software-particularly software that can be remotely accessed-in the functioning of the devices, which generates privacy and security issues; the impact of continual development and improvement of the device; and the influence of commercial interests in the context of a medical device market in which there are several competing products. Finally, we offer some initial suggestions as to how these questions should be answered.

Boronic acid (BA), known to be a reversible glucose-sensing material, is conjugated to a nanogel (NG) derived from hyaluronic acid biopolymer and used as a guest material for a carbon multiwalled nanotube (MWNT) yarn. By exploiting the swelling/deswelling of the NG that originates from the internal anionic charge changes resulting from BA binding to glucose, a NG MWNT yarn artificial muscle is obtained that provides reversible torsional actuation that can be used for glucose sensing. This actuator shows a short response time and high sensitivity (in the 5-100 × 10(-3) m range) for monitoring changes in glucose concentration in physiological buffer, without using any additional auxiliary substances or an electrical power source. It may be possible to apply the glucose-sensing MWNT yarn muscles as implantable glucose sensors that automatically release drugs when needed or as an artificial pancreas.

Purpose Posttraumatic partial or total iris defects often cause significant debilitating glare, photophobia, decreased vision and cosmetic problems. Currently, the best cosmetic results can be obtained with a customized silicone iris prosthesis. However, little is known about the functional results and the rate of complication if this type of iris prosthesis is implanted into severely traumatized eyes. The aim of this study is to analyse the functional and cosmetic outcomes as well as complications after Artificial Iris implantation. Methods A consecutive series of 34 patients who received a customized silicone iris prosthesis after severe globe injury with total or sub-total iris loss was analysed retrospectively. Additionally, patients were interviewed regarding change in subjective complaints. Results Median follow-up was 24 months (range 12.0–48.8). Mean visual acuity prior to Artificial Iris implantation was 1.1 logMAR (range 0.3–2.6). Five patients (15%) had pre-existing glaucoma and eight patients (24%) had pre-existing hypotony. Visual acuity 12 months after surgery was 1.4 logMAR (range 0.2–2.6). Complications included newly diagnosed glaucoma in three eyes (9%) and hypotony in three eyes (9%), persisting intraocular inflammation or macular oedema in seven patients (21%), and corneal endothelial decompensation requiring corneal transplantation in six patients (18%). Patients’ satisfaction increased by reducing glare and enhanced cosmetic appearance. Conclusion The customized silicone iris prosthesis is an individualized treatment approach with appealing cosmetic results. Therefore, especially traumatized eyes with highly different posttraumatic conditions could benefit. However, in some patients, the implantation of this device may cause an increase of intraocular pressure, corneal endothelial decompensation or persisting inflammation.

Purpose To describe a new wet lab model of Descemet membrane endothelial keratoplasty (DMEK) using human corneas mounted on an artificial anterior chamber with an artificial iris and to compare the performance time and scores between beginners and experienced anterior segment surgeons. Methods Corneas were mounted on an artificial chamber. To simulate an anterior chamber and to avoid loosing the graft into the tubing, a 3D printed iris was added. Each DMEK procedure required only one cornea for graft preparation, insertion, orientation, unfolding and centration. Ten human research corneas were used for training purposes. Intraoperative OCT was only used to validate the different steps of the procedure. Operators were divided into two groups, two beginners and three experienced DMEK surgeons. Results All DMEK procedures were successfully performed. Descemet's tears were frequent but harvesting was successful in all procedures. All combinations of graft unfolding techniques were possible. Experienced surgeons performed statistically better then beginners with faster harvesting (12.8 versus 28.2 min; p = 0.02) and insertion (13.5 versus 20.8 min; p = 0.05) times and better performance score (94 versus 52; p = 0.03). Conclusion This DMEK wet lab model offers a close to reality, feasible, resource-sparing and valid teaching technique that permits to perform all DMEK surgical steps. It also offers the possibility of varying the surgical difficulty by changing the anterior chamber depth.

In a study published in late April in Nature Communications, the authors were able to sustain 105- to 115-day-old premature lamb fetuses-whose level of development was comparable to that of a twenty-three-week-old human fetus-for four weeks in an artificial womb, enabling the lambs to develop in a way that paralleled age-matched controls. The oldest lamb of the set, more than a year old at the time the paper came out, appeared completely normal. This kind of research brings us one step closer to providing excellent quality of life for premature newborns, but it also portends major legal and ethical questions, especially for abortion rights in America.

Purpose: To measure the through-focus curve for eyes implanted with a type 1 Boston keratoprosthesis (KPro) and compare it to that of pseudophakic controls with fixed pupil sizes. The results should assist in evaluating postoperative visual quality after surgery. They should also help to determine the necessary KPro inventories in terms of refractive power steps. Methods: Autorefraction and manifest refraction were performed on all eyes. The monocular through-focus acuity curve was plotted in reference to the bestcorrected visual acuity by spectacle plane defocus ranging from +5.00 to 5.00 dioptres in 0.50 dioptre increments. These measurements were obtained on KPro-implanted eyes, pseudophakic eyes as controls, and on the same control eyes after fixing the pupil diameter to 3 and 2 mm using black painted iris contact lenses. Results: Ten KPro eyes and five control eyes were included. Good agreement was noted between the subjective refractions and autorefraction in KPro eyes. The average through-focus curve for the control eyes was significantly steeper than that of the KPro curve, but became comparable after fixing the control pupil to 2 and 3 mm. Conclusion: The KPro’s wide depth-of-focus makes the visual acuity less dependent on an exact refractive correction at distance and explains the ‘pseudoaccomodation’ experienced by these patients. This is primarily due to the small pupil diameter of the KPro. The current manufacturing steps in 0.50 dioptre increments appears to be sufficient.

Biomaterials play a critical role in modern medicine as surgical guides, implants for tissue repair, and as drug delivery systems. The emerging paradigm of precision medicine exploits individual patient information to tailor clinical therapy. While the main focus of precision medicine to date is the design of improved pharmaceutical treatments based on "-omics" data, the concept extends to all forms of customized medical care. This includes the design of precision biomaterials that are tailored to meet specific patient needs. Additive manufacturing (AM) enables free-form manufacturing and mass customization, and is a critical enabling technology for the clinical implementation of precision biomaterials. Materials scientists and engineers can contribute to the realization of precision biomaterials by developing new AM technologies, synthesizing advanced (bio)materials for AM, and improving medical-image-based digital design. As the field matures, AM is poised to provide patient-specific tissue and organ substitutes, reproducible microtissues for drug screening and disease modeling, personalized drug delivery systems, as well as customized medical devices.

Nature has created many perfect helical microstructures, including DNA, collagen fibrils, and helical blood vessels, to achieve unique physiological functions. While previous studies have developed a number of microfabrication strategies, the preparation of complex helical structures and cell-laden helical structures for biomimetic applications remains challenging. In this study, a one-step microfluidics-based methodology is presented for preparing complex helical hydrogel microfibers and cell-laden helical hydrogel microfibers. Several types of complex helical structures, including multilayer helical microfibers and superhelical hollow microfibers with helical channels, are prepared by simply tuning the flow rates or modifying the geometry of microfluidic device. With the decent perfusability, the hollow microfibers may simulate the structural characteristics of helical blood vessels and create swirling blood flow in a blood-vessel-on-chip setup. Such hydrogel-based helical microstructures may potentially be used in areas such as blood vessel tissue engineering, organ-on-chips, drug screening, and biological actuators.

It is often pointed out that one cannot be "a little bit pregnant," but pregnancy's borders are no longer so crisp. At Children's Hospital of Philadelphia, scientists have created an artificial womb in which "extremely premature" lambs were nurtured for four weeks, enough to make them ready to meet the world. The goal is to advance this technology until it is available for very premature human infants. At present, we put preemies into neonatal intensive care units, which are extremely stressful for the babies and their families, and the things we do to try to support them often cause serious damage. If successful, the artificial womb could be a terrific technology. The implications are remarkable. Would humans become somewhat like marsupials? Now, one is either born or not. Would this technology create a new, intermediate stage? What would this mean ethically and legally?

Objectives/Hypothesis Artificial tracheas prepared using a collagen sponge and polypropylene mesh have been implanted in patients who received tracheal resections, but epithelialization in the reconstructed area is slow. We determined the optimal bovine atelocollagen concentration necessary for the rapid and complete tracheal epithelial coverage of collagen sponge implants. Study Design Preliminary animal experiment. Methods Collagen sponges were prepared using lyophilizing 0.5%, 0.7%, and 1.0% atelocollagen solutions (0.5%, 0.7%, and 1.0% sponges) and were analyzed using scanning electron microscopy. Partial tracheal defects were prepared in rabbits and reconstructed using sponges. Epithelial regeneration in the reconstructed area was evaluated by endoscopic, histological, and scanning electron microscope analyses. Results All sponges had a membranous structural framework, and numerous fibrous structures filled the spaces within the framework in the 0.5% sponges. The membranous structure in the 0.7% sponges branched at many points, and intermembrane spaces were frequently observed. Conversely, the membranous structure in the 1.0% sponges was relatively continuous, thick, and closely arranged. Two weeks after implantation, tracheal defects were entirely covered with epithelium in two of the four and three of the four of the 0.5% and 0.7% sponge-implanted rabbits, respectively. The collagen sponges remained exposed to the tracheal lumen in four of the four rabbits in the 1.0% sponge group. Ciliogenesis in the center of the epithelialized region was detected only in the 0.7% sponge group. Conclusion Collagen sponges prepared from various concentrations of bovine atelocollagen have different structures. Complete epithelial coverage was achieved in more rabbits implanted with sponges prepared using the 0.7% bovine atelocollagen solution than in those implanted with sponges prepared from the 0.5% and 1.0% solutions. Level of Evidence NA Laryngoscope, 126:E396–E403, 2016

Block copolymer elastomer conductors (BEC) are mixtures of block copolymers grafted with conducting polymers, which are found to support very large strains, while retaining a high level of conductivity. These novel materials may find use in stretchable electronics. The use of BEC is demonstrated in a capacitive strain sensor and in an artificial muscle of the dielectric elastomer actuator type, supporting more than 100% actuation strain and capacity strain sensitivity up to 300%.

Regenerative medicine deals with the repair or the replacement of tissues and organs using advanced materials and methodologies. Regenerative nanomedicine uses nanoparticles containing gene transcription factors and other modulating molecules that allow reprogramming of cells in vivo as well as nanomaterials to induce selective differentiation of neural progenitor cells and to create neural-mechanical interfaces. In this article, we consider some applications of nanotechnology that may be useful for the treatment of degenerative retinal diseases, for example, use of nanoparticles for drug and gene therapy, use of nanomaterials for neural interfaces and extracellular matrix construction for cell-based therapy and neural prosthetics, and the use of bionanotechnology to re-engineer proteins and cell behavior for regenerative medicine.

Many biological organisms employ microand nanoscale systems to actuate structural components with a high degree of spatial control. The resulting patterned or predetermined movement of the components gives rise to versatile biological materials with locally reconfigurable features and regionspecific dynamic properties. On the molecular level, biological systems may regulate the availability of catalytic sites on enzymes by local reconfiguration of the protein structure, such as in allosteric modulation. On the microscale, echinoderms use actuating pedicellariae for particle capture and release, and body cleaning, and bacteria employ the movement of flagella to generate directional locomotion. Squid use the mechanical expansion and contraction of chromatophores to reversibly change color and pattern for camouflage and communication. These systems provide inspiration for the development of artificial “smart” materials and surfaces with similar properties that respond autonomously and reversibly to environmental cues. Recently, such reversibly responsive materials, particularly those patterned or manipulated on the nanoand microscale, have been the subject of intense research because of their promising impact in areas including sensors and actuators, microfluidic systems, microelectromechanical systems, and switchable surfaces with adaptive wettability, optical, mechanical, or adhesive properties. In particular, hydrogels can be tailored to respond volumetrically to a wide variety of stimuli including temperature, pH, light, and biomolecules (e.g., glucose), and there has been a significant amount of research and applications devised for this class of materials in areas ranging from tissue engineering to responsive photonics. We recently described a responsive and reversibly actuating surface based on a hybrid architecture consisting of passive polymeric structural (“skeletal”) elements embedded in and under the control of a responsive hydrogel layer (“muscle”) attached to a solid support. While the volume change of the polymer muscle enables large-area, directional movement of skeletal elements, anchoring to a solid support imposes a serious constraint on the capacity for hydrogel expansion or contraction, thus limiting the extent of induced actuation of the structural elements. Moreover, this approach does not allow the formation of hydrogel islands that would induce localized actuation of selected areas and the associated regional changes in surface properties. To expand the opportunities for integration of hydrogels in such composite systems, it would be advantageous to tailor not only the chemistry and swelling properties of the hydrogels but also the size, shape, and placement of the gel in relation to other system components. For example, welldefined, three dimensionally patterned, responsive hydrogel pads placed at the tips of micropillars with microscale control would enable nearly unrestricted gel swelling, both in and out of plane, which would locally actuate the pillars with more precise control over the movement of individual elements. While extensive research has been devoted to tailoring the swelling, chemical properties, and responsive behavior of hydrogels, less attention has been paid to the development of patterning protocols that would offer area-specific synthesis and 3D control over the microor nanoscale features of the gel. Many routes to defining hydrogel patterns have been explored including photolithography, soft lithography, and masking techniques, but these 2D approaches lack [*] Prof. C. J. Brinker, Dr. B. Kaehr Advanced Materials Laboratory, Sandia National Laboratories 1001 University Blvd. SE, Albuquerque, NM 87106 (USA) and Department of Chemical and Nuclear Engineering and Center for Micro-engineered Materials, University of New Mexico Albuquerque, NM 87106 (USA) E-mail: bjkaehr@sandia.gov

Purpose: To determine the value of electroretinography (ERG) and visual evoked potential (VEP) in predicting visual outcome in patients undergoing osteo-keratoprosthesis (OKP) or osteo-odonto-keratoprosthesis (OOKP) surgery. Methods: We performed a retrospective cohort study of 143 eyes in 101 patients who underwent OKP or OOKP surgery. The subjects underwent ERG, VEP testing or both up to 6 months prior to surgery. The ERG and VEP results were classified into four categories based on wave amplitude, latency and configuration. The main outcome was the maximum best-corrected visual acuity (maxBCVA) reached at any time postoperatively. Results: One hundred thirty-four cases had undergone preoperative ERG, 82 VEP and 73 both examinations. The sensitivities of ERG and VEP to detect maxBCVA ≥ 0.05 were 68.5% and 87%, respectively, while the specificity was 63.2% for ERG and 47.4% for VEP. The maxBCVA was significantly better in patients with normal ERG (p = 0.033) and those with normal VEP (p = 0.048), once having defined appropriate normal and abnormal cut-off levels. When comparing fellow eyes in patients who underwent surgery in both eyes, maxBCVA was better in the eyes that had better VEP results (p = 0.013). Conclusion: Eyes demonstrating normal ERG or VEP achieved better visual outcome than those with abnormal results. In addition, VEP proved instrumental in determining the eye with the best prognosis when comparing both eyes of a given patient.

A superaligned carbon nanotube (CNT) array is a special kind of vertically aligned CNT array with the capability of being converted into continuous fi lms and yarns. The as-produced CNT fi lms are transparent and highly conductive, with aligned CNTs parallel to the direction of drawing. After passing through volatile solutions or being twisted, CNT fi lms can be further condensed into shrunk yarns. These shrunk yarns possess high tensile strengths and Young’s moduli, and are good conductors. Many applications of CNT fi lms and shrunk yarns have been demonstrated, such as TEM grids, loudspeakers, touch screens, etc.

Developing a method to non-invasively monitor tissue engineered constructs is critical for the optimization of construct design and for assessing therapeutic efficacy. For this purpose, NMR is a powerful technique that can be used to obtain both images and spectroscopic data. But the inherent sensitivity of NMR limits the observation of a bioartificial construct with current NMR surface coil technology. In this study, we address this limitation through the development of an inductively-coupled, implantable coil system, demonstrate its use at high field (11.1T), and investigate the use of this coil system for monitoring a bioartificial construct in vitro and in vivo. The results establish that large gains in signal-to-noise can be obtained with this coil system over that obtainable with a surface coil. This coil system provides a means to quantitatively analyze the structure and function of implanted bioartificial organs.

Control trials and statistical analysis were carried out to assess the effects of albumin-collodion microencapsulated activated charcoal (ACAC) hemoperfusion on fulminant hepatic coma. A rat model of galactosamine induced fulminant hepatic coma was used. Rats which did not recover died at 3.0+/-0.6 days after galactosamine injection. Those which survived this period recovered. Forty-eight hours after galactosamine injection, a test group of 21 rats were treated with 1 hour hemoperfusion and compared with an untreated group of 23 rats. 71.4% of the treated group survived as compared to 30.4% of the untreated rats. Statistical analysis (t test) shows a significant increase in recovery for the treated group (less than 0.01). Biochemical and histological results will be discussed.

We compared various methods to control blood flow for extrauterine incubation of goat fetuses without lung respiration using arterio-venous extracorporeal membrane oxygenation via umbilical vessels to develop a suitable system for a long-term life support system for premature neonates. In twenty-seven consecutive preparations of goat fetuses, 4 designs (System 1, manual flow control without a reservoir; System 2, manual flow control with an arterial open-top reservoir; System 3, semiautomatic flow control with an arterial open top reservoir; and System 4, semiautomatic flow control with a tube occluder and an arterial open top reservoir) were tested in terms of the duration of incubation periods during which fetuses were kept under stable conditions. The incubation periods be-came prolonged with the advancement of the system (System 1, 5.4 h; System 2, 11.6 h; System 3, 64.8 h; and System 4, 159.8 h medians of the incubation periods). The incubation periods with System 4 were significantly longer compared to those with System 1 and System 2. These results suggest that, for extrauterine incubation of goat fetuses using arterio-venous extracorporeal membrane oxygenation via umbilical vessels, the method to control blood flow is of utmost importance for long-term maintenance, and thus a control system with the fixed vascular resistance of the extracorporeal circuit is applicable to long-term maintenance of premature goat fetuses.

Although many artificial organs have come to be used clinically, there still remain many problems such as thrombus formation, calcification, infection, malfunction, etc., that sometimes expose the patient to danger. One of the causes of these damages is that we do not know the true mechanisms of these phenomena. In other words, the design criteria of implant devices have not yet been established under scientific basis. It is very important that we artificial organ researchers and manufacturers establish the implant science of artificial organs. In this paper, mention is made of the kinds of factors we should consider for the design of artificial organs and how we should approach them scientifically. Also introduced is our approach method for an implantable total artificial heart.

With a view toward furthering the development of artificial liver systems, we have been culturing hepatocytes in vitro. The object of this research was to investigate the ideal conditions of oxygen tension for the efficient functioning of hepatocytes. Viable hepatocytes isolated from rat livers were cultured under five different oxygen tensions: 5, 10, 20, 50 and 90% O2. DNA contents, gluconeogenesis, urea synthesis, adenosine triphosphate (ATP) levels, and lipid peroxidation of hepatocytes were evaluated. Under the 5% oxygen conditions, the function of hepatocytes was very inferior and was accompanied by a low ATP level. However, hepatocytes cultured under 90% oxygen tension functioned less effectively than the control (20% O2) with elevated lipid peroxidation. The data in this study suggest that the optimum oxygen condition for cultured hepatocytes is 10 approximately 50%, and that especially under conditions of 20% oxygen tension, i.e., that of the ordinary atmosphere, hepatocytes can function most effectively.

Since 1987, we have been developing a bioartificial liver (BAL) using multiplated cultured hepatocyte monolayers. With the goal of promoting hepatic functions of cultured hepatocyte monolayers, we combined the use of a collagen gel layer over the monolayers of hepatocytes and/or cocultured hepatocytes with nonparenchymal cells (NPCs). The study was divided into four groups according to culture configurations: Group 1: hepatocyte monolayer culture (control); Group 2: coculture of hepatocytes and NPCs; Group 3: hepatocyte monolayer with a overlaid collagen gel layer; and Group 4: coculture with a overlaid collagen gel layer. The culture continued for 14 days. Morphological changes and hepatic functions were evaluated by urea and albumin syntheses. The morphological status of the hepatocytes remained for 2 weeks in Groups 3 and 4. Deterioration and detachment of hepatocytes and/or NPCs started in Group 1 and 2 on the third day in culture. Significantly high urea synthesis was noted in Group 4 (p < 0.001 compared with Group 1 and 2: p = 0.0014 compared with Group 3). Although there was no significant difference in albumin synthesis among the four groups, those hepatocytes covered by the collagen gel (Groups 3 and 4) tended to secrete albumin throughout the observation period. These results indicted that the environment, although artificial (but close to the in vivo state), supplied with collagen gel and the coculture, enhanced the activities of the cultured hepatocyte monolayers. We suggest that use of cocultured hepatocytes under a collagen gel is a promising candidate for a bioreactor of multiplated BAL.

The first artificial cells were prepared 35 years ago. They contain biologically active materials. They are now being used in medicine and biotechnology. Artificial cells containing adsorbents are already a routine form of treatment in hemoperfusion. This includes treatment for acute poisoning, high blood aluminum and iron, kidney failure, some types of acute liver failure, and other conditions. Artificial cells are being tested for use as red blood cell substitutes. Artificial cells containing cell culture are being tested in animals for the treatment of diabetes, liver failure, and others. Artificial cells containing enzymes are being tested for treatment in hereditary enzyme deficiency diseases and other diseases. Artificial cells containing complex enzyme system can convert wastes like urea and ammonia into useful amino acids. In biotechnology, artificial cells are being used for the production of monoclonal antibodies, interferons, and other biotechnological products. They are also being investigated for use in other applications in biotechnology, chemical engineering, and medicine.

Artificial liver support requires more than a detoxification system. We have investigated additional approaches. Microencapsulated hepatocytes increased the survival time of fulminant hepatic failure (FHF) rats. They also lowered the bilirubin in Gunn rats. Xenograft of microencapsulated rat hepatocytes into mice are immunoisolated. The viability of hepatocyte increased from 62 to 100% after 29 days. This is because of accumulation of a hepatic stimulatory factor (> 100,000 D) secreted by the hepatocytes in the artificial cells. A novel two-step method of cell encapsulation greatly improved immu-noisolation and biocompatibility. Other metabolic approaches included a multienzyme system for conversion of ammonia to essential amino acid, and removal of bilirubin.

Techniques are described for the coating of sorbents to be used in an artificial liver support system based on mixed sor‐bent bed hemoperfusion. Activated charcoal has been coated with cellulose acetate (CA) by solvent evaporation. With Amberlite XAD‐4, the Wurster technique was used for coating with CA. XAD‐4 has also been coated with a synthetic poly‐electrolyte with anticoagulant activity by adsorption and fixation by gamma radiation‐induced crosslinking. Activated charcoal, XAD‐4, and a cation exchange resin, all in powdered form, were encapsulated in agarose gel beads. Adsorption characteristics onto the sorbents are described. The results are in agreement with a theoretical model presented. In general, adsorption onto XAD‐4 is limited by film diffusion. With activated charcoal, pore diffusion limitation is generally observed. Blood compatibility is improved by coating.

Good antiinfection properties of medical poly- mers, especially those used in artificial organs, are crucial to the minimization of microbial attack in nosocomial treatments. However, medical polymers fabricated by con- ventional methods usually have unstable and short-lived antimicrobial effects because of unsteady out-diffusion of the antibacterial species from the organic matrix. Here, we introduce a dual plasma implantation process to enhance the properties. An inorganic antibacterial element, copper, is introduced into a medical polymer, polyethylene (PE), by means of copper plasma immersion ion implantation (PIII) and a subsequent nitrogen PIII process is used to regulate the release of the implanted Cu. X-ray photoelec- tron spectroscopy and transmission electron microscopy reveal that a relatively large amount of copper of about 11% is implanted into PE to a depth of several hundred nanometers. Chemical analyses confirm that the implanted Cu does not bond with the polymer matrix. However, the N2 plasma treatment produces various functional bonds such as C¼ ¼N, and CBN which exert appreciable influence on regulating the out-diffusion rate of copper. The large amount of embedded Cu, coupled with controlled release of the element to the surface, gives rise to excellent and long-lasting surface antibacterial properties of the plasma- treated polymer. The capability of controlling the release and storing the antibacterial reagent in a buried layer leads to better antimicrobial polymeric materials for medicine. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 83A: 838-844, 2007

UCL Institute of Women’s Health, Elizabeth Garrett Anderson and Obstetric Hospital, Huntley Street, London, WC1E 6DH, UKCorrespondence: Miss SM Creighton, UCL Institute of Women’s Health, Elizabeth Garrett Anderson and Obstetric Hospital, Huntley Street,London UKWC1E 6DH, UK. Email sarah.creighton@uclh.nhs.ukAccepted 12 September 2007.