scholarly journals Bioresorbable Multilayer Photonic Cavities as Temporary Implants for Tether-Free Measurements of Regional Tissue Temperatures

BME Frontiers ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Wubin Bai ◽  
Masahiro Irie ◽  
Zhonghe Liu ◽  
Haiwen Luan ◽  
Daniel Franklin ◽  
...  
Keyword(s):  
Optical Measurements ◽  
Deep Tissue ◽  
Near Surface ◽  
Surgical Extraction ◽  
Subcutaneous Tissues ◽  
Physical Interfaces ◽  
Photonic Cavities ◽  
Implanted Devices

Objective and Impact Statement. Real-time monitoring of the temperatures of regional tissue microenvironments can serve as the diagnostic basis for treating various health conditions and diseases. Introduction. Traditional thermal sensors allow measurements at surfaces or at near-surface regions of the skin or of certain body cavities. Evaluations at depth require implanted devices connected to external readout electronics via physical interfaces that lead to risks for infection and movement constraints for the patient. Also, surgical extraction procedures after a period of need can introduce additional risks and costs. Methods. Here, we report a wireless, bioresorbable class of temperature sensor that exploits multilayer photonic cavities, for continuous optical measurements of regional, deep-tissue microenvironments over a timeframe of interest followed by complete clearance via natural body processes. Results. The designs decouple the influence of detection angle from temperature on the reflection spectra, to enable high accuracy in sensing, as supported by in vitro experiments and optical simulations. Studies with devices implanted into subcutaneous tissues of both awake, freely moving and asleep animal models illustrate the applicability of this technology for in vivo measurements. Conclusion. The results demonstrate the use of bioresorbable materials in advanced photonic structures with unique capabilities in tracking of thermal signatures of tissue microenvironments, with potential relevance to human healthcare.

Healing effects of curcumin nanoparticles in deep tissue injury mouse model.

2020 ◽  
Vol 18 ◽  
Author(s):  
Zirui Zhang ◽  
Shangcong Han ◽  
Panpan Liu ◽  
Xu Yang ◽  
Jing Han ◽  
...  
Keyword(s):  
Wound Healing ◽  
Mrna Expression ◽  
Tissue Injury ◽  
Inflammatory Cells ◽  
Pcr Analysis ◽  
Protective Effects ◽  
Deep Tissue ◽  
Deep Tissue Injury

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.

scholarly journals Evaluation of In Vivo Spike Detection Algorithms for Implantable MTA Brain—Silicon Interfaces

2020 ◽  
Vol 10 (3) ◽  
pp. 26
Author(s):  
Mattia Tambaro ◽  
Elia Arturo Vallicelli ◽  
Gerardo Saggese ◽  
Antonio Strollo ◽  
Andrea Baschirotto ◽  
...  
Keyword(s):  
Energy Operator ◽  
Oxide Semiconductor ◽  
Detection Accuracy ◽  
Noise Power ◽  
Spike Detection ◽  
Power Budget ◽  
Detection Algorithms ◽  
Implanted Devices

This work presents a comparison between different neural spike algorithms to find the optimum for in vivo implanted EOSFET (electrolyte–oxide-semiconductor field effect transistor) sensors. EOSFET arrays are planar sensors capable of sensing the electrical activity of nearby neuron populations in both in vitro cultures and in vivo experiments. They are characterized by a high cell-like resolution and low invasiveness compared to probes with passive electrodes, but exhibit a higher noise power that requires ad hoc spike detection algorithms to detect relevant biological activity. Algorithms for implanted devices require good detection accuracy performance and low power consumption due to the limited power budget of implanted devices. A figure of merit (FoM) based on accuracy and resource consumption is presented and used to compare different algorithms present in the literature, such as the smoothed nonlinear energy operator and correlation-based algorithms. A multi transistor array (MTA) sensor of 7 honeycomb pixels of a 30 μm2 area is simulated, generating a signal with Neurocube. This signal is then used to validate the algorithms’ performances. The results allow us to numerically determine which is the most efficient algorithm in the case of power constraint in implantable devices and to characterize its performance in terms of accuracy and resource usage.

scholarly journals Reassessing the Role of Intra-Arterial Drug Delivery for Glioblastoma Multiforme Treatment

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Jason A. Ellis ◽  
Matei Banu ◽  
Shaolie S. Hossain ◽  
Rajinder Singh-Moon ◽  
Sean D. Lavine ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Optical Measurements ◽  
Pharmacological Agents ◽  
Cellular Targets ◽  
Therapeutic Landscape ◽  
Rational Drug

Effective treatment for glioblastoma (GBM) will likely require targeted delivery of several specific pharmacological agents simultaneously. Intra-arterial (IA) delivery is one technique for targeting the tumor site with multiple agents. Although IA chemotherapy for glioblastoma (GBM) has been attempted since the 1950s, the predicted benefits remain unproven in clinical practice. This review focuses on innovative approaches to IA drug delivery in treating GBM. Guided by novel in vitro and in vivo optical measurements, newer pharmacokinetic models promise to better define the complex relationship between background cerebral blood flow and drug injection parameters. Advanced optical technologies and tracers, unique nanoparticles designs, new cellular targets, and rational drug formulations are continuously modifying the therapeutic landscape for GBM. Personalized treatment approaches are emerging; however, such tailored approaches will largely depend on effective drug delivery techniques and on the ability to simultaneously deliver multidrug regimens. These new paradigms for tumor-selective drug delivery herald dramatic improvements in the effectiveness of IA chemotherapy for GBM. Therefore, within this context of so-called “precision medicine,” the role of IA delivery for GBM is thoroughly reassessed.

Fluorescein-Inspired Near-Infrared Chemodosimeter for Luminescence Bioimaging

2019 ◽  
Vol 26 (21) ◽  
pp. 4029-4041 ◽  
Author(s):  
Hai-Yan Wang ◽  
Huisheng Zhang ◽  
Siping Chen ◽  
Yi Liu
Keyword(s):  
Near Infrared ◽  
Living System ◽  
Tissue Penetration ◽  
Deep Tissue ◽  
Biological Targets ◽  
Nir Dyes ◽  
Photo Damage ◽  
Temporal And Spatial

Luminescence bioimaging is widely used for noninvasive monitoring of biological targets in real-time with high temporal and spatial resolution. For efficient bioimaging in vivo, it is essential to develop smart organic dye platforms. Fluorescein (FL), a traditional dye, has been widely used in the biological and clinical studies. However, visible excitation and emission limited their further application for in vivo bioimaging. Nearinfrared (NIR) dyes display advantages of bioimaging because of their minimum absorption and photo-damage to biological samples, as well as deep tissue penetration and low auto-luminescence from background in the living system. Thus, some great developments of near-infrared fluorescein-inspired dyes have emerged for bioapplication in vitro and in vivo. In this review, we highlight the advances in the development of the near-infrared chemodosimeters for detection and bioimaging based on the modification of fluoresceininspired dyes naphtho-fluorescein (NPF) and cyanine-fluorescein (Cy-FL).

Dipetalonema viteae and Brugia pahangi transplant infections in gerbils for use in antifilarial screening

1988 ◽  
Vol 62 (1) ◽  
pp. 1-9 ◽  
Author(s):  
J. P. Court ◽  
J. N. Stables ◽  
G. M. Lees ◽  
M. R. Martin-Short ◽  
R. Rankin
Keyword(s):  
Peritoneal Cavity ◽  
Drug Efficacy ◽  
Brugia Pahangi ◽  
Subcutaneous Tissues ◽  
Worm Migration ◽  
Antifilarial Activity ◽  
Dipetalonema Viteae ◽  
Migration Response

ABSTRACTTransplanted infections of Dipetalonema viteae and Brugia pahangi have been evaluated as tools for experimental chemotherapy. Attempts were made to establish these filariae in similar pharmacokinetic sites within the same host, so that direct comparisons of in vivo drug susceptibilities could be made. Unfortunately, it was not possible to establish B. pahangi in the subcutaneous tissues, the preferred site of D. viteae. Therefore, intraperitoneal B. pahangi and subcutaneously implanted D. viteae in gerbils were used for the study. D. viteae infections were significantly enhanced by concomitant infections with B. pahangi, while B. pahangi infection rates were unaffected by the presence of D. viteae. Experiments with amoscanate, CGP6140 and Mel W demonstrated the importance of employing both B. pahangi and D. viteae for antifilarial discovery work and the fundamental effect of parasite location on drug efficacy. D. viteae rapidly migrate from the peritoneal cavity of gerbils following implantation; twenty one hours after infection 73% of transplanted worms were found in the subcutaneous tissues. It was shown that the migration response could be used as a stringent parameter for demonstrating antifilarial activity. D. viteae were exposed to antifilarial drugs for 24 hours in vitro, washed and implanted into the peritoneal cavity of gerbils. At autopsy, 5 days later, 10−8M ivermectin and milbemycin D had prevented migration; CGP6140, amoscanate, suramin, flubendazole and furapyrimidone were also detected at <10−6M using this parameter. In all cases the migration response was more sensitive to drugs than parasite kill. Ivermectin's ability to inhibit worm migration through the tissues is discussed, with respect to the role of itinerant males in the reproductive cycle of Onchocerca volvulus.

scholarly journals Deep-Tissue Photothermal Therapy Using Laser Illumination at NIR-IIa Window

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Xunzhi Wu ◽  
Yongkuan Suo ◽  
Hui Shi ◽  
Ruiqi Liu ◽  
Fengxia Wu ◽  
...  
Keyword(s):  
Photothermal Therapy ◽  
Near Infrared ◽  
Laser Excitation ◽  
Tumor Treatment ◽  
Deep Tissue ◽  
Laser Illumination ◽  
Nir Light ◽  
Cell Ablation

Abstract Photothermal therapy (PTT) using near-infrared (NIR) light for tumor treatment has triggered extensive attentions because of its advantages of noninvasion and convenience. The current research on PTT usually uses lasers in the first NIR window (NIR-I; 700–900 nm) as irradiation source. However, the second NIR window (NIR-II; 1000–1700 nm) especially NIR-IIa window (1300–1400 nm) is considered much more promising in diagnosis and treatment as its superiority in penetration depth and maximum permissible exposure over NIR-I window. Hereby, we propose the use of laser excitation at 1275 nm, which is approved by Food and Drug Administration for physical therapy, as an attractive technique for PTT to balance of tissue absorption and scattering with water absorption. Specifically, CuS-PEG nanoparticles with similar absorption values at 1275 and 808 nm, a conventional NIR-I window for PTT, were synthesized as PTT agents and a comparison platform, to explore the potential of 1275 and 808 nm lasers for PTT, especially in deep-tissue settings. The results showed that 1275 nm laser was practicable in PTT. It exhibited much more desirable outcomes in cell ablation in vitro and deep-tissue antitumor capabilities in vivo compared to that of 808 nm laser. NIR-IIa laser illumination is superior to NIR-I laser for deep-tissue PTT, and shows high potential to improve the PTT outcome.

Biphasic and Preferentially Oriented Microcrystalline Calcium Phosphate Coatings: In Vitro and In Vivo Studies

2005 ◽  
Vol 284-286 ◽  
pp. 207-210 ◽  
Author(s):  
Hyun Bin Kim ◽  
Yogesh K. Vohra ◽  
Patrick J. Louis ◽  
William R. Lacefield ◽  
Jack E. Lemons ◽  
...  
Keyword(s):  
In Vivo Studies ◽  
In Vitro Dissolution ◽  
Thin Film Coatings ◽  
In Vivo Experiments ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
Surgical Extraction ◽  
Calcium Phosphate Coatings

We report results of in-vitro and in-vivo studies on biphasic thin film coatings of hydroxyapatite/tetracalcium phosphate produced by pulsed laser deposition using ablation targets of crystalline hydroxyapatite. Changes in coating phase composition during in-vitro dissolution experiments were monitored by x-ray diffraction. Scanning electron microscopy was used to assess variations in surface morphology. In-vivo experiments involving the insertion of coated metallic implants in the proximal tibia and distal femur of New Zealand White Rabbits were carried out. Histomorphometric studies on implant samples after surgical extraction show that biphasic coatings produced may lead to enhanced osteointegration compared to pure hydroxyapatite coatings.

scholarly journals Upconversion superballs for programmable photoactivation of therapeutics

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhen Zhang ◽  
Muthu Kumara Gnanasammandhan Jayakumar ◽  
Xiang Zheng ◽  
Swati Shikha ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Endosomal Escape ◽  
Infrared Light ◽  
Deep Tissue ◽  
Sequential Activation ◽  
Uv Visible ◽  
Favorable Conditions ◽  
Multiple Molecules

Abstract Upconversion nanoparticles (UCNPs) are the preferred choice for deep-tissue photoactivation, owing to their unique capability of converting deep tissue-penetrating near-infrared light to UV/visible light for photoactivation. Programmed photoactivation of multiple molecules is critical for controlling many biological processes. However, syntheses of such UCNPs require epitaxial growth of multiple shells on the core nanocrystals and are highly complex/time-consuming. To overcome this bottleneck, we have modularly assembled two distinct UCNPs which can individually be excited by 980/808 nm light, but not both. These orthogonal photoactivable UCNPs superballs are used for programmed photoactivation of multiple therapeutic processes for enhanced efficacy. These include sequential activation of endosomal escape through photochemical-internalization for enhanced cellular uptake, followed by photocontrolled gene knockdown of superoxide dismutase-1 to increase sensitivity to reactive oxygen species and finally, photodynamic therapy under these favorable conditions. Such programmed activation translated to significantly higher therapeutic efficacy in vitro and in vivo in comparison to conventional, non-programmed activation.

scholarly journals Noncontact Optical Measurement of Aqueous Humor Glucose Levels and Correlation with Serum Glucose Levels in Rabbit

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 387
Author(s):  
Yih-Shiou Hwang ◽  
Eugene Yu-Chuan Kang ◽  
Chia-Rui Shen ◽  
Wei-Hsin Hong ◽  
Wei-Chi Wu
Keyword(s):  
Aqueous Humor ◽  
Optical System ◽  
Near Infrared ◽  
Optical Measurement ◽  
Serum Glucose ◽  
Mean Difference ◽  
Optical Measurements ◽  
Glucose Levels

The noninvasive measurement of serum glucose levels has been investigated for the monitoring of blood sugar control in diabetes. In our study, we aimed to develop a novel noncontact glucometer (NCGM) utilizing an optical approach to measure the intraocular aqueous humor glucose levels in the anterior chamber of rabbit eyes. The NCGM consists of a hybrid optical system that simultaneously measures near-infrared absorption and the polarized rotatory distribution of glucose molecules in the aqueous humor. In vitro optical measurements demonstrated that NCGM measurements had high precision and repeatability for different glucose levels, including 50 mg/dL (14.36%), 100 mg/dL (−4.05%), 200 mg/dL (−5.99%), 300 mg/dL (4.86%), 400 mg/dL (−2.84%), 500 mg/dL (−0.11%), and 600 mg/dL (4.48%). In the rabbit experiments, we found a high correlation between aqueous glucose levels and serum glucose levels, with a mean difference of 8 mg/dL. According to the testing results, the in vivo NCGM measurement of aqueous humor glucose levels also displayed a high correlation with serum glucose levels, with a mean difference of 29.2 mg/dL. In conclusion, aqueous humor glucose levels were accurately measured using the NCGM, and the results correlated with serum glucose levels.

scholarly journals Multifunctional AIE iridium (III) photosensitizer nanoparticles for two-photon-activated imaging and mitochondria targeting photodynamic therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuzi Cai ◽  
Kang-Nan Wang ◽  
Wen Ma ◽  
Yuanyuan Yang ◽  
Gui Chen ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Water Solubility ◽  
Tissue Imaging ◽  
Ros Generation ◽  
Generation Efficiency ◽  
Deep Tissue ◽  
Two Photon ◽  
Mitochondria Targeting

AbstractDeveloping novel photosensitizers for deep tissue imaging and efficient photodynamic therapy (PDT) remains a challenge because of the poor water solubility, low reactive oxygen species (ROS) generation efficiency, serve dark cytotoxicity, and weak absorption in the NIR region of conventional photosensitizers. Herein, cyclometalated iridium (III) complexes (Ir) with aggregation-induced emission (AIE) feature, high photoinduced ROS generation efficiency, two-photon excitation, and mitochondria-targeting capability were designed and further encapsulated into biocompatible nanoparticles (NPs). The Ir-NPs can be used to disturb redox homeostasis in vitro, result in mitochondrial dysfunction and cell apoptosis. Importantly, in vivo experiments demonstrated that the Ir-NPs presented obviously tumor-targeting ability, excellent antitumor effect, and low systematic dark-toxicity. Moreover, the Ir-NPs could serve as a two-photon imaging agent for deep tissue bioimaging with a penetration depth of up to 300 μm. This work presents a promising strategy for designing a clinical application of multifunctional Ir-NPs toward bioimaging and PDT.

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