228 research outputs found
Implantable Photovoltaic Cell Using Upconversion Nanoparticles for On-Demand Drug Delivery Devices
No full text1
Upconversion Nanoparticles/HA-Rose Bengal Conjugate Complex for Noninvasive Photochemical Tissue Bonding
No full text2
Upconversion Nanoparticles / Hyaluronate-Rose Bengal Conjugate Complex for Noninvasive Photochemical Tissue Bonding
No full text2
Upconversion nanoparticles / hyaluronate-rose bengal conjugate complex for noninvasive photochemical tissue bonding
No full text2
Organic Transistor-Based Chemical Sensors for Wearable Bioelectronics
No full textCONSPECTUS: Bioelectronics for healthcare that monitor the health information on users in real time have stepped into the limelight as crucial electronic devices for the future due to the increased demand for "point-of-care" testing, which is defined as medical diagnostic testing at the time and place of patient care. In contrast to traditional diagnostic testing, which is generally conducted at medical institutions with diagnostic instruments and requires a long time for specimen analysis, point-of-care testing can be accomplished personally at the bedside, and health information on users can be monitored in real time. Advances in materials science and device technology have enabled next-generation electronics, including flexible, stretchable, and biocompatible electronic devices, bringing the commercialization of personalized healthcare devices increasingly within reach, e.g., wearable bioelectronics attached to the body that monitor the health information on users in real time. Additionally, the monitoring of harmful factors in the environment surrounding the user, such as air pollutants, chemicals, and ultraviolet light, is also important for health maintenance because such factors can have short- and long-term detrimental effects on the human body. The precise detection of chemical species from both the human body and the surrounding environment is crucial for personal health care because of the abundant information that such factors can provide when determining a person's health condition. In this respect, sensor applications based on an organic-transistor platform have various advantages, including signal amplification, molecular design capability, low cost, and mechanical robustness (e.g., flexibility and stretchability). This Account covers recent progress in organic transistor-based chemical sensors that detect various chemical species in the human body or the surrounding environment, which will be the core elements of wearable electronic devices. There has been considerable effort to develop high-performance chemical sensors based on organic-transistor platforms through material design and device engineering. Various experimental approaches have been adopted to develop chemical sensors with high sensitivity, selectivity, and stability, including the synthesis of new materials, structural engineering, surface functionalization, and device engineering. In this Account, we first provide a brief introduction to the operating principles of transistor-based chemical sensors. Then we summarize the progress in the fabrication of transistor-based chemical sensors that detect chemical species from the human body (e.g., molecules in sweat, saliva, urine, tears, etc.). We then highlight examples of chemical sensors for detecting harmful chemicals in the environment surrounding the user (e.g., nitrogen oxides, sulfur dioxide, volatile organic compounds, liquid-phase organic solvents, and heavy metal ions). Finally, we conclude this Account with a perspective on the wearable bioelectronics, especially focusing on organic electronic materials and devices.11sciescopu
Hyaluronate and Its Derivatives for Customized Biomedical Applications
No full textSince hyaluronate (HA) was firstly isolated from the vitreous of bovine eyes in 1934, HA has been widely
investigated for various biomedical applications. As a naturally-occurring polysaccharide, HA has been
used for joint lubrication and ocular treatment in its intact form due to the excellent biocompatibility,
viscoelasticity, biodegradability, and hygroscopic properties. HA can be easily functionalized via the
chemical modification of its carboxyl and hydroxyl groups. Recently, a variety of biological functions of
HA have been explored and a number of customized applications have been investigated taking advantages
of the interaction between HA and biological tissues. HA has been used for drug delivery to
enhance the blood circulation time of drugs with target-specificity to HA receptors in the body. HA has
been also used to prepare tissue engineering hydrogel scaffolds for the spatiotemporal control of
encapsulated cells. In this review, we describe the key biological functions of HA in the body in terms of
its structure, physical properties, biodistribution and interaction with HA receptors. After that, we
describe unique advantages that allow HA to be applied in various biomedical fields. Finally, we report
the conventional and newly emerging applications of HA and its derivatives under commercial development
stages.1114sciescopu
A Single-Center Retrospective Analysis of Periprocedural Variables Affecting Local Tumor Progression after Radiofrequency Ablation of Colorectal Cancer Liver Metastases
No full textBackground: Local tumor progression (LTP) is associated with poorer survival in patients undergoing radiofrequency ablation (RFA) for colorectal liver metastasis (CLM). An algorithmic strategy to predict LTP may help in selection of patients who would benefit most from RFA for CLM. Purpose: To estimate local tumor progression-free survival (LTPFS) following RFA of CLM and develop an algorithmic strategy based on clinical variables. Materials and Methods: In this retrospective study, between March 2000 and December 2014, patients who underwent percutaneous RFA for CLM were randomly split into development (60%) and internal validation (40%) data sets. Kaplan-Meier method was used to estimate LTPFS and overall survival (OS) rates. Independent factors affecting LTPFS in the development data set were investigated by using multivariable Cox proportional hazard regression analysis. Risk scores were assigned to the risk factors and applied to the validation data set. Results: A total of 365 patients (mean age, 60 years 6 11 [standard deviation]; 259 men) with 512 CLMs were evaluated. LTPFS and OS rates were 85% and 92% at 1 year, 73% and 41% at 5 years, 72% and 30% at 10 years, and 72% and 28% at 15 years, respectively. Independent risk factors for LTP included tumor size of 2 cm or greater (hazard ratio [HR], 3.8; 95% CI: 2.3, 6.2; P < .001), subcapsular tumor location (HR, 1.9; 95% CI: 1.1, 3.1; P = .02), and minimal ablative margin of 5 mm or less (HR, 11.7; 95% CI: 4.7, 29.2; P < .001). A prediction model that used the risk factors had areas under the curve of 0.89, 0.92, and 0.90 at 1, 5, and 10 years, respectively, and it showed significantly better areas under the curve when compared with the model using the minimal ablative margin of 5 mm or less alone. Conclusion: Radiofrequency ablation provided long-term control of colorectal liver metastases. Although minimal ablative margin of 5 mm or less was the most dominant factor, the multifactorial approach including tumor size and subcapsular location better predicted local tumor progression-free survival. (C) RSNA, 202011Nsciescopu
- …
