Fcg-Former: Identification of Functional Groups in FTIR Spectra Using Enhanced Transformer-Based Model.

Deep learning (DL) is becoming more popular as a useful tool in various scientific domains, especially in chemistry applications. In the infrared spectroscopy field, where identifying functional groups in unknown compounds poses a significant challenge, there is a growing need for innovative approaches to streamline and enhance analysis processes. This study introduces a transformative approach leveraging a DL methodology based on transformer attention models. With a data set containing approximately 8677 spectra, our model utilizes self-attention mechanisms to capture complex spectral features and precisely predict 17 functional groups, outperforming conventional architectures in both functional group prediction accuracy and compound-level precision. The success of our approach underscores the potential of transformer-based methodologies in enhancing spectral analysis techniques.

Electrochemical detection of nalbuphine drug using oval-like ZnO nanostructure-based sensor.

Monitoring pharmaceutical drugs in various mediums is crucial to mitigate adverse effects. This study presents a chemical sensor using an oval-like zinc oxide (ZnO) nanostructure for electrochemical detection of nalbuphine. The ZnO nanostructure, produced via an efficient sol-gel technique, was extensively characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-visible spectrophotometry, and fourier transform infrared spectroscopy (FTIR). A slurry of the ZnO nanostructure in a binder was applied to a glassy carbon electrode (GCE). The sensor's responsiveness to nalbuphine was assessed using linear sweep voltammetry (LSV), achieving optimal performance by fine-tuning the pH. The sensor demonstrated a proportional response to nalbuphine concentrations up to 150.0 nM with a good regression coefficient (R2) and a detection limit of 6.20 nM (S/N ratio of 3). Selectivity was validated against various interfering substances, and efficacy was confirmed through real sample analysis, highlighting the sensor's successful application for nalbuphine detection.

Balloon-assisted laser application for endoscopic treatment of biliary stricture.

OBJECTIVES: Malignant biliary stricture is a ductal narrowing of the bile duct that is often diagnosed at an advanced stage, leading to difficulty in resection. The current study aims to evaluate the feasibility of endobiliary laser treatment by quantifying the extent of coagulative necrosis in tissue under various conditions. METHODS: Ex vivo and in vivo porcine bile tissues were used for endobiliary laser treatment to characterize the dosimetric responses of the tissue to various treatment conditions: power level, irradiation time, and number of treatments. 532 nm laser light was coupled with a balloon-integrated diffusing applicator (BDA) to deliver the laser light endoscopically for tissue coagulation. The coagulated regions (maximum length and depth) in the treated tissues were evaluated histologically for quantitative comparison. RESULTS: Dosimetric evaluations with ex vivo liver tissue confirmed that both maximum length and depth of coagulative necrosis (CN) increased with applied power and number of treatments. Ex vivo bile duct tests demonstrated that BDA-assisted laser treatment at 10 W for 12 s reproducibly yielded CN with a length of 5.8 ± 1.6 mm and a depth of 0.6 ± 0.2 mm. In vivo tests presented that endoscopic laser treatment using the BDA created CN on the ductal surface without any perforation. Microscopic examinations revealed that a dense inflammatory cell infiltration and eosinophilic area in the in vivo treated tissue. The extent of CN in the in vivo tissue was 40% longer and 120% deeper (length: 8.1 ± 0.7 mm; depth: 1.3 ± 0.2 mm), compared to that in the ex vivo tissue. CONCLUSION: BDA-assisted laser treatment could be a feasible option for endoscopic treatment of biliary stricture with uniform ablation at the circumference of bile duct. Further in vivo studies will be performed in a large number of stricture-developed porcine models to examine both efficacy and safety of the proposed endobiliary laser treatment for clinical translations.

Comparative Evaluations on Real-Time Monitoring of Temperature Sensors during Endoscopic Laser Application.

Temperature sensors, such as Fiber Bragg Grating (FBG) and thermocouple (TC), have been widely used for monitoring the interstitial tissue temperature during laser irradiation. The aim of the current study was to compare the performance of both FBG and TC in real-time temperature monitoring during endoscopic and circumferential laser treatment on tubular tissue structure. A 600-µm core-diameter diffusing applicator was employed to deliver 980-nm laser light (30 W for 90 s) circumferentially for quantitative evaluation. The tip of the TC was covered with a white tube (W-TC) in order to prevent direct light absorption and to minimize temperature overestimation. The temperature measurements in air demonstrated that the measurement difference in the temperature elevations was around 3.5 °C between FBG and W-TC. Ex vivo porcine liver tests confirmed that the measurement difference became lower (less than 1 °C). Ex vivo porcine esophageal tissue using a balloon-integrated catheter exhibited that both FBG and W-TC consistently showed a comparable trend of temperature measurements during laser irradiation (~2 °C). The current study demonstrated that the white tube-covered TC could be a feasible sensor to monitor interstitial tissue temperature with minimal overestimation during endoscopic laser irradiation. Further in vivo studies on gastroesophageal reflux disease will investigate the performance of the W-TC to monitor the temperature of the esophageal mucosa surface in real-time mode to warrant the safety of endoscopic laser treatment.

A Lipophilic IR-780 Dye-Encapsulated Zwitterionic Polymer-Lipid Micellar Nanoparticle for Enhanced Photothermal Therapy and NIR-Based Fluorescence Imaging in a Cervical Tumor Mouse Model.

To prolong blood circulation and avoid the triggering of immune responses, nanoparticles in the bloodstream require conjugation with polyethylene glycol (PEG). However, PEGylation hinders the interaction between the nanoparticles and the tumor cells and therefore limits the applications of PEGylated nanoparticles for therapeutic drug delivery. To overcome this limitation, zwitterionic materials can be used to enhance the systemic blood circulation and tumor-specific delivery of hydrophobic agents such as IR-780 iodide dye for photothermal therapy. Herein, we developed micellar nanoparticles using the amphiphilic homopolymer poly(12-(methacryloyloxy)dodecyl phosphorylcholine) (PCB-lipid) synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The PCB-lipid can self-assemble into micelles and encapsulate IR-780 dye (PCB-lipid-IR-780). Our results demonstrated that PCB-lipid-IR-780 nanoparticle (NP) exhibited low cytotoxicity and remarkable photothermal cytotoxicity to cervical cancer cells (TC-1) upon near-infrared (NIR) laser irradiation. The biodistribution of PCB-lipid-IR-780 showed higher accumulation of PCB-lipid-IR-780 than that of free IR-780 in the TC-1 tumor. Furthermore, following NIR laser irradiation of the tumor region, the PCB-lipid-IR-780 accumulated in the tumor facilitated enhanced tumor ablation and subsequent tumor regression in the TC-1 xenograft model. Hence, these zwitterionic polymer-lipid hybrid micellar nanoparticles show great potential for cancer theranostics and might be beneficial for clinical applications.

3D printing-assisted fabrication of double-layered optical tissue phantoms for laser tattoo treatments.

BACKGROUND AND OBJECTIVE: Artificial skin phantoms have been developed as an alternative tissue for human skin experiments due to convenient use and easy storage. However, fabricating both thin (∼100 µm) epidermis and relatively thick dermis is often cumbersome, and most developed phantoms have hardly reflected specific human skin types. The objective of this study was to fabricate skin phantoms with 3D printing technique to emulate various human skin types (I-VI) along with the corresponding optical and mechanical properties for laser tattoo removal. STUDY DESIGN/MATERIALS AND METHODS: Both gelatin and agar powders were mixed with coffee and TiO2 particles to fabricate skin phantoms with materials properties for various skin types (I-VI). A 3D printer was employed to precisely control the thickness of each phantom for epidermis and dermis layers. A number of concentrations of the coffee and TiO2 particles were used to determine the degree of absorption and scattering effects in various skin types. The optical properties between 500 and 1,000 nm for the fabricated phantoms were measured by double-integrating spheres with an inverse adding-doubling (IAD) algorithm. Optical coherence tomography (OCT) and rheometer were also utilized to evaluate optical (absorption and reduced scattering coefficients) and mechanical properties (compression modulus) of the fabricated phantoms, respectively. RESULTS: Visible color inspections presented that the skin phantoms for types I, III, and VI similarly emulated the color space of the human skin types. The optical property measurements demonstrated that the absorption (µa) and reduced scattering (µ(s')) coefficients decreased with wavelengths. Compared to the human skin type VI, a dermis phantom represented quite equivalent values of µa and µ(s') whereas an epidermis phantom showed up to 30% lower µa but almost identical µ(s') over the wavelengths. The OCT measurements confirmed that the thicknesses of the epidermis and the dermis phantoms were measured to be 138.50 ± 0.01 µm and 0.81 ± 0.04 mm, respectively. The mechanical properties of the phantoms mixed with the agar volume of 40% yielded a compression modulus of 83.7 ± 14.8 kPa, which well corresponded to that of human forearm skin (50-95 kPa). CONCLUSION: The 3D printing technique was able to reliably fabricate the double-layered phantoms emulating a variety of skin types (I-VI) along with the comparable optical and mechanical properties. Further investigations will incorporate artificial chromophores into the fabricated skin phantoms to reliably evaluate the new therapeutic wavelengths for laser tattoo removal.

Leveraging Deep Learning for Fine-Grained Categorization of Parkinson's Disease Progression Levels through Analysis of Vocal Acoustic Patterns.

Speech impairments often emerge as one of the primary indicators of Parkinson's disease (PD), albeit not readily apparent in its early stages. While previous studies focused predominantly on binary PD detection, this research explored the use of deep learning models to automatically classify sustained vowel recordings into healthy controls, mild PD, or severe PD based on motor symptom severity scores. Popular convolutional neural network (CNN) architectures, VGG and ResNet, as well as vision transformers, Swin, were fine-tuned on log mel spectrogram image representations of the segmented voice data. Furthermore, the research investigated the effects of audio segment lengths and specific vowel sounds on the performance of these models. The findings indicated that implementing longer segments yielded better performance. The models showed strong capability in distinguishing PD from healthy subjects, achieving over 95% precision. However, reliably discriminating between mild and severe PD cases remained challenging. The VGG16 achieved the best overall classification performance with 91.8% accuracy and the largest area under the ROC curve. Furthermore, focusing analysis on the vowel /u/ could further improve accuracy to 96%. Applying visualization techniques like Grad-CAM also highlighted how CNN models focused on localized spectrogram regions while transformers attended to more widespread patterns. Overall, this work showed the potential of deep learning for non-invasive screening and monitoring of PD progression from voice recordings, but larger multi-class labeled datasets are needed to further improve severity classification.

Beta cyclodextrin conjugated AuFe3O4 Janus nanoparticles with enhanced chemo-photothermal therapy performance.

The strategic integration of multi-functionalities within a singular nanoplatform has received growing attention for enhancing treatment efficacy, particularly in chemo-photothermal therapy. This study introduces a comprehensive concept of Janus nanoparticles (JNPs) composed of Au and Fe3O4 nanostructures intricately bonded with ß-cyclodextrins (ß-CD) to encapsulate 5-Fluorouracil (5-FU) and Ibuprofen (IBU). This strategic structure is engineered to exploit the synergistic effects of chemo-photothermal therapy, underscored by their exceptional biocompatibility and photothermal conversion efficiency (∼32.88 %). Furthermore, these ß-CD-conjugated JNPs enhance photodynamic therapy by generating singlet oxygen (1O2) species, offering a multi-modality approach to cancer eradication. Computer simulation results were in good agreement with in vitro and in vivo assays. Through these studies, we were able to prove the improved tumor ablation ability of the drug-loaded ß-CD-conjugated JNPs, without inducing adverse effects in tumor-bearing nude mice. The findings underscore a formidable tumor ablation potency of ß-CD-conjugated Au-Fe3O4 JNPs, heralding a new era in achieving nuanced, highly effective, and side-effect-free cancer treatment modalities. STATEMENT OF SIGNIFICANCE: The emergence of multifunctional nanoparticles marks a pivotal stride in cancer therapy research. This investigation unveils Janus nanoparticles (JNPs) amalgamating gold (Au), iron oxide (Fe3O4), and ß-cyclodextrins (ß-CD), encapsulating 5-Fluorouracil (5-FU) and Ibuprofen (IBU) for synergistic chemo-photothermal therapy. Demonstrating both biocompatibility and potent photothermal properties (∼32.88 %), these JNPs present a promising avenue for cancer treatment. Noteworthy is their heightened photodynamic efficiency and remarkable tumor ablation capabilities observed in vitro and in vivo, devoid of adverse effects. Furthermore, computational simulations validate their interactions with cancer cells, bolstering their utility as an emerging therapeutic modality. This endeavor pioneers a secure and efficacious strategy for cancer therapy, underscoring the significance of ß-CD-conjugated Au-Fe3O4 JNPs as innovative nanoplatforms with profound implications for the advancement of cancer therapy.

A grain-like cerium oxide nanostructure: synthesis and uric acid sensing application.

Utilizing nanomaterials on the working electrode of sensors enables the fabrication of highly sensitive devices for the detection of various analytes. Herein, a facile synthesis method is used to formulate a grain-like cerium oxide (CeO2) nanostructure. The structural features and surface properties of the synthesized CeO2 nanostructure were studied, which showed that the CeO2 nanostructure exhibited grain-like morphology, good crystalline structure, and excellent vibrational properties. To evaluate the sensing properties of grain-like CeO2 nanostructure, nanomaterial slurry was prepared in butyldiglycol acetate binder. Then, the nanomaterial slurry was drop-casted onto the working electrode of the screen-printed carbon electrode (SPCE) to fabricate the CeO2-modified SPCE sensor. The sensor's electrochemical properties were analysed, which showed excellent charge-transfer behavior compared to the bare SPCE. CV-based electrochemical sensing of uric acid (UA) on a CeO2-modified SPCE sensor exhibited excellent linear performance up to 1070 µM UA. Moreover, the sensor offers good sensitivity, low detection limit, reproducibility, selectivity, and long-term stability. The CeO2-modified SPCE sensor demonstrated a promising application for UA detection in real samples, addressing the need for timely UA concentration monitoring.

Surface-engineered vertically-aligned ZnO nanorod for sensitive non-enzymatic electrochemical monitoring of cholesterol.

Developing highly sensitive and selective non-enzymatic electrochemical biosensors for disease biomarker detection has become challenging in healthcare applications. However, advances in material science are opening new avenues for creating more dependable biosensing technologies. In this context, the present work introduces a novel approach by engineering a hybrid structure of zinc oxide nanorod (ZnO NR) modified with iron oxide nanoparticle (Fe2O3 NP) on an FTO electrode. This Fe2O3 NP-ZnO NR hybrid material functions as a nanozyme, facilitating the catalysis of cholesterol and enabling the direct transfer of electrons to the fluorine-doped tin oxide (FTO) electrode, limiting the need for costly and traditional enzymes in the detection process. This innovative non-enzymatic cholesterol biosensor showcases remarkable sensitivity, registering at 642.8 µA/mMcm2 within a linear response range of up to 9.0 mM. It also exhibits a low detection limit (LOD) of ∼12.4 µM, ensuring its capability to detect minimal concentrations of cholesterol accurately. Moreover, the developed biosensor displays exceptional selectivity by effectively distinguishing cholesterol molecules from other interfering biological species, while exhibiting outstanding stability and reproducibility. Our findings indicate that the Fe2O3 NP-ZnO NR hybrid nanostructure on the FTO electrode holds promise for enhancing biosensor stability. Furthermore, the present device fabrication platform offers versatility, as it can be adapted with various enzymes or modified with different metal oxides, potentially broadening its applicability in a wide range of biomarkers detection.

Precision-engineered metal and metal-oxide nanoparticles for biomedical imaging and healthcare applications.

The growing field of nanotechnology has witnessed numerous advancements over the past few years, particularly in the development of engineered nanoparticles. Compared with bulk materials, metal nanoparticles possess more favorable properties, such as increased chemical activity and toxicity, owing to their smaller size and larger surface area. Metal nanoparticles exhibit exceptional stability, specificity, sensitivity, and effectiveness, making them highly useful in the biomedical field. Metal nanoparticles are in high demand in biomedical nanotechnology, including Au, Ag, Pt, Cu, Zn, Co, Gd, Eu, and Er. These particles exhibit excellent physicochemical properties, including amenable functionalization, non-corrosiveness, and varying optical and electronic properties based on their size and shape. Metal nanoparticles can be modified with different targeting agents such as antibodies, liposomes, transferrin, folic acid, and carbohydrates. Thus, metal nanoparticles hold great promise for various biomedical applications such as photoacoustic imaging, magnetic resonance imaging, computed tomography (CT), photothermal, and photodynamic therapy (PDT). Despite their potential, safety considerations, and regulatory hurdles must be addressed for safe clinical applications. This review highlights advancements in metal nanoparticle surface engineering and explores their integration with emerging technologies such as bioimaging, cancer therapeutics and nanomedicine. By offering valuable insights, this comprehensive review offers a deep understanding of the potential of metal nanoparticles in biomedical research.

An Electroanalytical Enzymeless α-Fe2O3-ZnO Hybrid Nanostructure-Based Sensor for Sensitive Quantification of Nitrite Ions.

Nitrite monitoring serves as a fundamental practice for protecting public health, preserving environmental quality, ensuring food safety, maintaining industrial safety standards, and optimizing agricultural practices. Although many nitrite sensing methods have been recently developed, the quantification of nitrite remains challenging due to sensitivity and selectivity limitations. In this context, we present the fabrication of enzymeless iron oxide nanoparticle-modified zinc oxide nanorod (α-Fe2O3-ZnO NR) hybrid nanostructure-based nitrite sensor fabrication. The α-Fe2O3-ZnO NR hybrid nanostructure was synthesized using a two-step hydrothermal method and characterized in detail utilizing x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). These analyses confirm the successful synthesis of an α-Fe2O3-ZnO NR hybrid nanostructure, highlighting its morphology, purity, crystallinity, and elemental constituents. The α-Fe2O3-ZnO NR hybrid nanostructure was used to modify the SPCE (screen-printed carbon electrode) for enzymeless nitrite sensor fabrication. The voltammetric methods (i.e., cyclic voltammetry (CV) and differential pulse voltammetry (DPV)) were employed to explore the electrochemical characteristics of α-Fe2O3-ZnO NR/SPCE sensors for nitrite. Upon examination of the sensor's electrochemical behavior across a range of nitrite concentrations (0 to 500 µM), it is evident that the α-Fe2O3-ZnO NR hybrid nanostructure shows an increased response with increasing nitrite concentration. The sensor demonstrates a linear response to nitrite concentrations up to 400 µM, a remarkable sensitivity of 18.10 µA µM-1 cm-2, and a notably low detection threshold of 0.16 µM. Furthermore, its exceptional selectivity, stability, and reproducibility make it an ideal tool for accurately measuring nitrite levels in serum, yielding reliable outcomes. This advancement heralds a significant step forward in the field of environmental monitoring, offering a potent solution for the precise assessment of nitrite pollution.

EEG and EMG-based human-machine interface for navigation of mobility-related assistive wheelchair (MRA-W).

The control of human-machine interfaces (HMIs), such as motorized wheelchairs, has been widely investigated using biopotentials produced by electrochemical processes in the human body. However, many studies in this field sometimes overlook crucial factors like special users' needs, who often have inadequate muscle mass and strength, and paresis needed to operate a wheelchair. This study proposes a novel solution: an economical, universally compatible, and user-centric manual-to-powered wheelchair conversion kit. The powered wheelchair is operated using a hybrid control system integrating electroencephalogram (EEG) and electromyography (EMG), utilizing an LSTM network. It uses a low-cost electroencephalogram (EEG) headset and a wearable electromyography (EMG) electrode armband to solve these constraints. The proposed system comprised three crucial objectives: the development of an EEG-based user attentive detection system, an EMG-based navigation system, and a transform conventional wheelchair into a powered wheelchair. Human test subjects were utilized to evaluate the proposed system, and the study complied with accepted ethical guidelines. We selected four EEG features (p < 0.023) for the attentive detection system and six EMG features (p < 0.037) to detect navigation intentions. User attentive detection was achieved at 83.33 (±0.34) %, while the navigation intention system produced 86.67 (±0.52) % accuracy. The overall system was successful in reaching an accuracy rate of 85.0 (±0.19) % and a weighted average precision of 0.89. After the dataset was trained using an LSTM network, the overall accuracy produced was 97.3 (±0.5) %, higher than the accuracy produced by the Quadratic SVM classifier. By giving older and disabled people a more convenient way to use powered wheelchairs, this research helps to build ergonomic and cost-effective biopotential-based HMIs, enhancing their quality of life.

Inhibitory effect of 405 nm laser light on bacterial biofilm in urethral stent.

The clinical use of urethral stents is usually complicated by various adverse effects, including dysuria, fever, and urinary tract infection (UTI). Biofilms (formed by bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) adhering to the stent cause UTIs in stented patients (approximately 11%). The undesirable consequences of antibiotics use include bacterial resistance, weight gain, and type 1 diabetes, which occur when antibiotics are used for a long time. We aimed to assess the efficacy of a new optical treatment with a 405 nm laser to inhibit bacterial growth in a urethral stent in vitro. The urethral stent was grown in S. aureus broth media for three days to induce biofilm formation under dynamic conditions. Various irradiation times with the 405 nm laser light were tested (5, 10, and 15 min). The efficacy of the optical treatment on biofilms was evaluated quantitatively and qualitatively. The production of reactive oxygen species helped eliminate the biofilm over the urethral stent after 405 nm irradiation. The inhibition rate corresponded to a 2.2 log reduction of colony-forming units/mL of bacteria after 0.3 W/cm2 of irradiation for 10 min. The treated stent showed a significant reduction in biofilm formation compared with the untreated stent, as demonstrated by SYTO 9 and propidium iodide staining. MTT assays using the CCD-986sk cell line revealed no toxicity after 10 min of irradiation. We conclude that optical treatment with 405 nm laser light inhibits bacterial growth in urethral stents with no or minimal toxicity.

Impact of H&E Stain Normalization on Deep Learning Models in Cancer Image Classification: Performance, Complexity, and Trade-Offs.

Accurate classification of cancer images plays a crucial role in diagnosis and treatment planning. Deep learning (DL) models have shown promise in achieving high accuracy, but their performance can be influenced by variations in Hematoxylin and Eosin (H&E) staining techniques. In this study, we investigate the impact of H&E stain normalization on the performance of DL models in cancer image classification. We evaluate the performance of VGG19, VGG16, ResNet50, MobileNet, Xception, and InceptionV3 on a dataset of H&E-stained cancer images. Our findings reveal that while VGG16 exhibits strong performance, VGG19 and ResNet50 demonstrate limitations in this context. Notably, stain normalization techniques significantly improve the performance of less complex models such as MobileNet and Xception. These models emerge as competitive alternatives with lower computational complexity and resource requirements and high computational efficiency. The results highlight the importance of optimizing less complex models through stain normalization to achieve accurate and reliable cancer image classification. This research holds tremendous potential for advancing the development of computationally efficient cancer classification systems, ultimately benefiting cancer diagnosis and treatment.

Hydroxyapatite: A journey from biomaterials to advanced functional materials.

Hydroxyapatite (HAp), a well-known biomaterial, has witnessed a remarkable evolution over the years, transforming from a simple biocompatible substance to an advanced functional material with a wide range of applications. This abstract provides an overview of the significant advancements in the field of HAp and its journey towards becoming a multifunctional material. Initially recognized for its exceptional biocompatibility and bioactivity, HAp gained prominence in the field of bone tissue engineering and dental applications. Its ability to integrate with surrounding tissues, promote cellular adhesion, and facilitate osseointegration made it an ideal candidate for various biomedical implants and coatings. As the understanding of HAp grew, researchers explored its potential beyond traditional biomaterial applications. With advances in material synthesis and engineering, HAp began to exhibit unique properties that extended its utility to other disciplines. Researchers successfully tailored the composition, morphology, and surface characteristics of HAp, leading to enhanced mechanical strength, controlled drug release capabilities, and improved biodegradability. These modifications enabled the utilization of HAp in drug delivery systems, biosensors, tissue engineering scaffolds, and regenerative medicine applications. Moreover, the exceptional biomineralization properties of HAp allowed for the incorporation of functional ions and molecules during synthesis, leading to the development of bioactive coatings and composites with specific therapeutic functionalities. These functionalized HAp materials have demonstrated promising results in antimicrobial coatings, controlled release systems for growth factors and therapeutic agents, and even as catalysts in chemical reactions. In recent years, HAp nanoparticles and nanostructured materials have emerged as a focal point of research due to their unique physicochemical properties and potential for targeted drug delivery, imaging, and theranostic applications. The ability to manipulate the size, shape, and surface chemistry of HAp at the nanoscale has paved the way for innovative approaches in personalized medicine and regenerative therapies. This abstract highlights the exceptional evolution of HAp, from a traditional biomaterial to an advanced functional material. The exploration of novel synthesis methods, surface modifications, and nanoengineering techniques has expanded the horizon of HAp applications, enabling its integration into diverse fields ranging from biomedicine to catalysis. Additionally, this manuscript discusses the emerging prospects of HAp-based materials in photocatalysis, sensing, and energy storage, showcasing its potential as an advanced functional material beyond the realm of biomedical applications. As research in this field progresses, the future holds tremendous potential for HAp-based materials to revolutionize medical treatments and contribute to the advancement of science and technology.

Development of Novel Balloon-Integrated Optical Catheter for Endoscopic and Circumferential Laser Application.

The current study aims to demonstrate the feasibility of a novel balloon-integrated optical catheter (BIOC) to achieve endoscopic laser application for circumferential coagulation of a tubular tissue structure. Both optical and thermal numerical simulations were developed to predict the propagation of laser light and a spatio-temporal distribution of temperature in tissue. Ex vivo esophagus tissue was tested with 980 nm laser light at 30 W for 90 s for quantitative evaluations. In vivo porcine models were used to validate the performance of BIOC for circumferential and endoscopic laser coagulation of esophagus in terms of acute tissue responses post-irradiation. Optical simulations confirmed that a diffusing applicator was able to generate a circumferential light distribution in a tubular tissue structure. Both numerical and experimental results presented that the maximum temperature elevation occurred at 3-5 mm (muscle layer) below the mucosa surface after 90 s irradiation. In vivo tests confirmed the circumferential delivery of laser light to a deep muscle layer as well as no evidence of thermal damage to the esophageal mucosa. The proposed BIOC can be a feasible optical device to provide circumferential laser irradiation as well as endoscopic coagulation of tubular esophagus tissue for clinical applications.

Yb-Gd Codoped Hydroxyapatite as a Potential Contrast Agent for Tumor-Targeted Biomedical Applications.

Recently, various nanomaterials based on hydroxyapatite (HAp) have been developed for bioimaging applications. In particular, HAp doped with rare-earth elements has attracted significant attention, owing to its enhanced bioactivity and imaging properties. In this study, the wet precipitation method was used to synthesize HAp codoped with Yb and Gd. The synthesized Ybx-Gdx-HAp nanoparticles (NPs) were characterized via various techniques to analyze the crystal phase, functional groups, thermal characteristics, and particularly, the larger surface area. The IR783 fluorescence dye and a folic acid (FA) receptor were conjugated with the synthesized Ybx-Gdx-HAp NPs to develop an effective imaging contrast agent. The developed FA/IR783/Yb-Gd-HAp nanomaterial exhibited improved contrast, sensitivity, and tumor-specific properties, as demonstrated by using the customized LUX 4.0 fluorescence imaging system. An in vitro cytotoxicity study was performed to verify the biocompatibility of the synthesized NPs using MTT assay and fluorescence staining. Photodynamic therapy (PDT) was also applied to determine the photosensitizer properties of the synthesized Ybx-Gdx-HAp NPs. Further, reactive oxygen species generation was confirmed by Prussian blue decay and a 2',7'-dichlorofluorescin diacetate study. Moreover, MDA-MB-231 breast cancer cells were used to evaluate the efficiency of Ybx-Gdx-HAp NP-supported PDT.

Antibacterial and antibiofilm activity of Abroma augusta stabilized silver (Ag) nanoparticles against drug-resistant clinical pathogens.

Infectious diseases remain among the most pressing concerns for human health. This issue has grown even more complex with the emergence of multidrug-resistant (MDR) bacteria. To address bacterial infections, nanoparticles have emerged as a promising avenue, offering the potential to target bacteria at multiple levels and effectively eliminate them. In this study, silver nanoparticles (AA-AgNPs) were synthesized using the leaf extract of a medicinal plant, Abroma augusta. The synthesis method is straightforward, safe, cost-effective, and environment friendly, utilizing the leaf extract of this Ayurvedic herb. The UV-vis absorbance peak at 424 nm indicated the formation of AA-AgNPs, with the involvement of numerous functional groups in the synthesis and stabilization of the particles. AA-AgNPs exhibited robust antibacterial and antibiofilm activities against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The MIC values of AA-AgNPs ranged from 8 to 32 µg/mL. Electron microscopic examination of the interaction of AA-AgNPs with the test bacterial pathogens showed a deleterious impact on bacterial morphology, resulting from membrane rupture and leakage of intracellular components. AA-AgNPs also demonstrated a dose-dependent effect in curtailing biofilm formation below inhibitory doses. Overall, this study highlights the potential of AA-AgNPs in the successful inhibition of both the growth and biofilms of MRSA and VRE bacteria. Following studies on toxicity and dose optimization, such AgNPs could be developed into effective medical remedies against infections.

Engineering and visualization of bacteria for targeting infarcted myocardium.

Optimization of the specific affinity of cardiac delivery vector could significantly improve the efficiency of gene/protein delivery, yet no cardiac vectors to date have sufficient target specificity for myocardial infarction (MI). In this study, we explored bacterial tropism for infarcted myocardium based on our previous observations that certain bacteria are capable of targeting the hypoxic regions in solid tumors. Out of several Escherichia coli or Salmonella typhimurium strains, the S. typhimurium defective in the synthesis of ppGpp (ΔppGpp S. typhimurium) revealed accumulation and selective proliferation in the infarcted myocardium without spillover to noncardiac tissue. The Salmonellae that were engineered to express a variant of Renilla luciferase gene (RLuc8), under the control of the E. coli arabinose operon promoter (P(BAD)), selectively targeted and delivered RLuc8 in the infarcted myocardium only upon injection of L-arabinose. An examination of the infarct size before and after infection, and estimations of C-reactive protein (CRP) and procalcitonin indicated that intravenous injection of ΔppGpp S. typhimurium did not induce serious local or systemic immune reactions. This current proof-of-principle study demonstrates for the first time the capacity of Salmonellae to target infarcted myocardium and to serve as a vehicle for the selective delivery of therapeutic agents in MI.