Recent Patents on Biomedical Engineering (Discontinued) - Volume 2, Issue 3, 2009

Recent progress in medical management has significantly improved the range of treatments for children with severe heart failure; however, some patients still suffer from refractory heart failure, necessitating heart transplantation. Transplantation is the definitive therapy for end-stage heart failure in children and adults; however, many patients die before transplantation because of the shortage of donor organs. Mechanical circulatory support devices have offered new treatment options for these patients. For many years, extracorporeal membrane oxygenation (ECMO) has served as the main circulatory assist device for children. However, long-term support with ECMO is not recommended because of the accompanying severe complications, such as cerebral infarction, brain hemorrhage, and renal and multiorgan failure. The development of ventricular assist devices specifically for children is lagging behind efforts aimed at treating adults. Furthermore, a total artificial heart is not thought suitable for children because of their growth rate. The National Heart, Lung, and Blood Institute has supported efforts to develop pediatric-specific devices at five institutions in the United States since 2004. There are only a few patents for circulatory support devices designed for pediatric patients, and there is still much room to improve currently available pediatric circulatory devices.

Increased intracranial pressure (ICP) is one of the major causes of secondary brain ischemia that accompanies a variety of pathological conditions, most notably, traumatic brain injury (TBI), stroke, and intracranial hemorrhages. However, aside from a few Level I trauma centers, ICP monitoring is rarely a part of the clinical management of patients with these conditions because of the invasiveness of the standard monitoring methods (which require insertion of a catheter into the cranium), additional risks they present for patients, high costs associated with the procedure, and the limited access to trained personnel, i.e., a neurosurgeon. Alternative methods have therefore been sought with which ICP can be measured noninvasively. This article reviews nearly 30 such methods patented over the past 25 years, which included ultrasound “time-of-flight” techniques, transcranial Doppler, methods based on acoustic properties of the cranial bones, EEG, MRI, tympanic membrane displacement, oto-acoustic emission, ophthalmodynamometry, and ultrasound measurements of optic nerve sheath diameter. At present, none of the methods is sufficiently accurate to allow for routine clinical use although several hold promise. Future developments should integrate further refinements of the existing methods, combined use of multiple sensors and/or technologies, and large clinical validation studies on relevant populations.

The ubiquitin-proteasome pathway (UPP) is the major proteolytic process that degrades the intracellular proteins in a regulated way. Deregulation of the UPP has been implicated in the pathogenesis of a number of major human diseases including cancer, viral infections, neurodegenerative disorder, cardiovascular disorder, diabetes, etc. The successful market of a patented drug bortezomib validated the proteasome as an effective target in the treatment of cancers. It also demonstrated the potential of proteasome as a biological target in the design of the drugs against other major human diseases stated above. This review presents the development status of the proteasome inhibitors and their application in many diseases and recent patent coverage.

The effects of visible light irradiation on various aspects of cell metabolism have been recognized in recent years, and extensive literature exists on the application of laser phototherapy in various biological systems. The biostimulative effect of light in the visible range has been attributed to minute amounts of light-induced reactive oxygen species (ROS) formation. In sperm cells, low amounts of ROS were found to enhance acrosome reaction and in vitro fertilization. These findings led us to patent a method for stimulating the fertilizing capability of sperm cells using light irradiation. In the present paper, US Patent No. 6379939 is discussed and results demonstrating light induced ROS in sperm cells are summarized.

Hydroxyapatite (HA) is commonly considered the most promising synthetic biomaterial for biomedical applications in orthopaedic, dental and maxillofacial surgery for its biocompatibility, bioresorption and bioactivity. Only recently a chemical-physical experimental approach has been utilized to investigate the capability of synthetic carbonated hydroxyapatite nanocrystals (CHA) to produce in vivo biomimetic mineral deposition on enamel and dentine surface through a daily use. Demineralised enamel and dentine slabs have been treated in vitro with synthetic biomimetic hydroxyapatite nanocrystals for a few minutes. This induced a surface remineralisation, forming a biomimetic apatite coating on enamel and dentine surface. In fact, enamel remineralisation quickly occurs thanks to the specific chemicalphysical characteristics of innovative nanostructured hydroxyapatite particles which closely resemble mineral enamel constituents. Therefore the experimental results suggest the possibility to perform teeth wear-deterioration prevention. Carbonated hydroxyapatite nanocrystals synthesized with tailored biomimetic characteristics for composition, structure, size and morphology can chemically bind themselves on the surfaces of teeth hard tissues, filling the scratches, producing a bound biomimetic apatitic coating, protecting the enamel surface structure. Over the past few decades many products for dental damage prevention (toothpastes, rinses and gels) have been commercialized and patented expressly for the fluoride remineralisation effect. Only recently the numerous applications of hydroxyapatite as bone filler biomaterial for implantation surgery have evidenced innovative and important opportunities for decay prevention through a daily use of oral care products containing hydroxyapatite. The aim of this paper is to review these recent patents and classify them according to their actual possibilities to safeguard teeth health.

Biodegradable elastomers have recently found widespread application in many areas of biomedical engineering such as tissue engineering, drug delivery, and bioimaging. In particular, the recent developments in research have led to the creation of citric acid based polymers with enhanced mechanical properties, novel design strategies for crosslinking, nanoporous features, and unique photoluminescent capabilities. The present review will cover the recent patents involving citric acid derived biodegradable biomaterials within the field of biomedical engineering including poly (diol citrates) and their composites, crosslinked urethane-doped polyesters (CUPEs), poly (alkylene maleate citrates) (PAMCs), poly (xylitol-co-citrates) (PXC), and aliphatic biodegradable photoluminescent polymers (BPLPs). The synthesis, development, and applications of these novel polymers will be discussed along with the current trends and future developments in the biomaterials field.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by medical imaging, bioinformatics, image processing, biomaterials, pharmaceutical drugs, bioengineering, medical devices, design, biological devices, biomechanics & diagnostic devices related to biomedical engineering.