This PDF file contains the front matter associated with SPIE Proceedings Volume 10893, including the Title Page, Copyright information, Table of Contents, and Author and Conference Committee lists.

Near infrared photoimmunotherapy (NIR-PIT) is a new molecularly-targeted cancer photo-therapy based on conjugating a near infrared silica-phthalocyanine dye, IRDye700DX (IR700), to a monoclonal antibody (mAb) targeting cell-surface molecules. NIR-PIT targeting EGFR using the cetuximab-IR700 conjugate is now in transition to fast-track global Phase 3 clinical trial in late-stage head and neck squamous cell cancer patients. When exposed to NIR light, the conjugate induces a highly-selective necrotic/immunogenic cell death (ICD) only in target-positive, mAb-IR700-bound cancer cells. This cell death occurs as early as 1 minute after exposure to NIR light. Meanwhile, immediately adjacent target-negative cells are unharmed. ICD induced by NIR-PIT promoted maturation of immature dendritic cells (DCs) to maturated DCs that primed cytotoxic T-cells to react with cancer-related antigens released from crashed cancer cells. Inhibition of immuno-checkpoints including PD-1/PD-L1 axis or CTLA-4 is one of several major methods for enhancing cytotoxicity of tumor-infiltrating T-cells. In this talk, I will focus on NIR-PIT combined with an immune-checkpoint inhibitor that could treat not only local tumors but also distant untreated tumors without recurrence in some syngeneic cancer models. Additionally, NIR-PIT combined with local tumor-infiltrating negative-regulatory T-cells by CD25-targeted NIR-PIT that is another major methods for enhancing cytotoxicity of tumor-infiltrating T-cells similarly operated in different tumor models. The regimens of NIR-PIT combined with methods for enhancing host tumor immunity could cure primary and metastatic tumor and yield vaccination effect against treated cancer cells that would be the ultimate form of NIR-PIT in oncology clinic.

During the recent years fluorescence spectroscopy applications focused on using longer wavelength fluorophores and new classes of vehicles delivering fluorophores such as nanoparticles. Silica nanoparticles synthesis is relatively straight forward using any of the well established methods (Strober, Reverse Emulsion, etc.,). The basis of these methods is the use of TEOS to form the silica nanoparticle. In addition to TEOS a wide range of modified TEOS is available commercially or can be synthesized using published synthetic schemes. Many different moieties, molecules can be used as substitution in the TEOS molecules and subsequently using these substituted analogs during the polymerization process of the silica nanoparticle. Following this process virtually any new property can be introduced in the silica nanoparticle. One of these is fluorescence using a wide range of fluorophores including visible or near-infrared dyes due to the wide availability of modified TEOS reactive analogues and reactive dyes. Silica nanoparticles containing copolymerized molecules can be utilized as fluorescence sensors if the copolymerized dye has sensing moieties, such as –COOH for pH measurements. One drawback of the direct facile synthesis using one or more modified TEOS in the same reaction is that the whole silica nanoparticle will have the property as determined by the modified TEOS. For example in the case of dyes containing functional moieties that can complex metal ions dye molecules will be located on the surface and the inner structure as well. For many biomedical and bioanalytical applications it may be desired the silica nanoparticle to have different surface and inner core properties. This can be achieved by using surface re-growth technique. For example the surface of the silica nanoparticle can be made very hydrophobic or hydrophilic opposite of the inner core; two different dyes can be present in these regions or make the silica nanoparticle surface to contain optically active enantiomers. This presentation compares the use of longer wavelength fluorophores to shorter wavelength counterparts. Surface properties can be modified by utilizing molecules that are themselves fluorescent, such as modifying surface hydrophobicity using hydrophobic surface dyes or non-hydrophobic dyes in the core with adding surface hydrophobicity with non-fluorescent hydrophobic molecules. Several additional surface modification moieties will be discussed along with their applications.

We demonstrate proof of concept for a point-of-care diagnostic that is used for the detection of chloride channel accessory 1 (CLCA1), a key regulator of mucus production. The prototypical device utilizes ultrasound-confined polystyrene (PS) microspheres held in a longitudinal standing bulk acoustic wave (LSBAW) as reaction substrates. Pressure field amplification between two included pillar arrays enables immobilization of these antigen-coated beads in a predetermined low-pressure region perpendicular to the direction of flow. Bronchoalveolar lavage (BAL) samples from IL-13 stimulated pigs were incubated overnight in a solution of untreated PS beads prior to channel introduction. A PZT- 8 piezoceramic transducer was used to actuate the channel (f_1,E = 575 kHz) to focus and confine the beads in a linear zero-pressure node. A solution of two proprietary anti-CLCA1 monoclonal antibodies (mAbs) modified with sulfocyanine3 (Cy3) NHS ester were flowed (7 μL/min, 15 min) into the channel and incubated for 1.5 hours. A solution of phosphate-buffered saline was then used to remove excess antibodies prior to channel/bead cluster imaging. The bead solution was collected, under no acoustic actuation, at the outlet for analysis by flow cytometry. Increased fluorescence over control samples (p<0.0001) demonstrated that the LSBAW platform can serve as a functional immunoassay to allow for serial, contactless reagent washes and fluorescent probe introduction.

The intestinal mucosal barrier prevents macromolecules and pathogens from entering the circulatory stream in a healthy gut. Tight junctions in this barrier are compromised in many intestinal disorders including inflammatory bowel diseases (such as Crohn’s and ulcerative colitis), celiac disease, graft vs host disease, environmental enteropathy, and enteric dysfunction. Dual sugar absorption tests are a standard method for measuring gastrointestinal integrity in humans. The larger molecular weight sugar, lactulose, is minimally absorbed through a healthy gut. The smaller molecular weight sugar, mannitol or rhamnose, in contrast, is readily absorbed through both a healthy and inflamed gut. Thus, a higher ratio of lactulose to mannitol or rhamnose reflects increased intestinal permeability. However, several issues prevent the widespread use of the dual sugar assay including requirements for lengthy urine collection, transport of specimens under conditions free from contamination and bacterial growth, analysis by sophisticated laboratory equipment, and the associated lengthy turnaround time. In a recent publication, the feasibility of employing a dual fluorescent tracer agent assay to mimic the dual sugar absorption test without the need for specimen collection was reported. This dual fluorophore assay for GI permeability was demonstrated in an indomethacin-induced bowel disease model in rats. However, one of the fluorophores was not entirely biocompatible. Herein is reported a dual fluorophore system that is totally biocompatible, with emphasis on the transdermal detection of the fluorophores, thus enabling the use of the technology for noninvasive point-of-care gastrointestinal permeability determination.

Space and time controllable drug delivery systems have gained interest due to their increased specificity and selectivity, compared to current cancer treatment methods. We present a novel type of multimodal contrast agents, that enhances contrast both in ultrasound and in photoacoustic imaging, while at the same time being capable of triggered drug delivery. These polymeric microcapsules consist of a biodegradable polymer shell, containing dye that encapsulates an oil core. Upon pulsed laser irradiation, polymeric microparticles can create a cavitation bubble that subsequently emits a strong acoustic wave. We investigated different formulations of these particles, by changing the oil content, dye concentration and probing conditions using a combination of pulsed laser excitation and an ultrasound chirp. As such we tested their applicability for medical imaging purposes. We demonstrated that the formulation containing a low boiling point oil core gives the highest photoacoustic and acoustic response. The laser activation threshold for this particle system, is relatively high but within the medical limits. The same system can produce a stable bubble. US scattering by this stable bubble results in medically relevant frequencies, making the particles of interest for biomedical and pre-clinical imaging. Additionally, the system has potential to be drug-bearing.

Transplanted stem cells suffer from poor viability, migration, and misguided delivery and thus improved imaging techniques are needed to increase the effectiveness of stem cell therapy. Here, we combined real-time acoustic imaging techniques with magnetic particle imaging (MPI) that offers zero background imaging for high contrast data sets. We used PLGA/iron oxide hybrid nanoparticles (diameter = 185 ± 2 nm) labeled with DiR as a trimodal contrast agent. The PLGA coating facilitated ultrasound backscatter, the DiR enhanced the photoacoustic signal, and the iron oxide generated the MPI signal. The in vitro limit of detection of the contrast media was 120 μg/mL for ultrasound, 24 μg/mL for photoacoustic, and 60 μg/mL for magnetic particle imaging. ICP-OES measurements determined that there were 1,043, 1,402, 4,542, 9,069,11,070, and 11,218 iron oxide particles in cells treated with concentrations of 2.4, 24, 60, 120,180, and 240 μg/ml nanobubbles respectively for 6 hrs. The human mesenchymal stem cells differentiated into adipogenic and osteogenic cell lines with no major morphological differences from non-treated cells. The nanoparticle-labeled stem cells were injected intracardially into live mice for real-time imaging. The ultrasound signal was 3.8-fold higher, the photoacoustic signal was 10.2 times higher (imaged at 730 nm), and the MPI signal was 20-fold higher in these stem cell-injected animals than in the control animals injected with PBS. The limit of detection was 10,461 cells for ultrasound and 996 cells for photoacoustics. This technique is advantageous over MRI techniques due to the ability to image stem cell injections in real-time combined with the very high signal-to-background of MPI.

We report a synthesis platform for manipulation, modification, and potential production of nanoscale reagents using microscale carrier particles confined to a longitudinal acoustic trap. Pairs of perforated “pseudo-walls” enhance the local acoustic pressure field to immobilize reaction substrates (polymeric or glass beads) from a heterogeneous suspension. Nodal regions (pressure minima) of the acoustic field are perpendicular to the inflow direction to enable continuous, contactless, serial chemical reactions on the microparticle surface for, e.g., antibody (Ab) attachment, alteration, and recovery. Here, we discuss the potential of longitudinal standing bulk acoustic wave (LSBAW) architectures for creation of antibody conjugates (ACs) at research and production scales. Results prove the feasibility of combining acoustic manipulation of microcarriers with steps constituting the synthesis and purification of ACs including mixing, washing, buffer exchange, conjugation reaction, and release/recovery. 10-μm diameter hollow glass spheres (HGS) were modified to create a Protein G-terminated self-assembled monolayer (SAM). Modified HGS were introduced and focused to the midline of the acoustic trap. Focused beads were then incubated with a solution of green fluorescent secondary antibodies (rabbit anti-goat IgG Alexa Fluor 488) for 45 minutes before flushing the channel with phosphate buffered saline (1xPBS). N- hydroxysuccinimide (NHS) chemistry was used to attach a sulfo-cyanine3 (Cy3) NHS ester dye to the immobilized antibodies to demonstrate a common conjugation technique. Finally, a low-pH release buffer was used for recovery. Flow cytometry and gel electrophoresis confirm successful AC assembly without damage due to ultrasound exposure. Potential scale-up strategies are also discussed.

Chemical reactions occurring in biological processes are either endergonic or exergonic, which exchange heat between the system and surrounding. Detecting thermogenic responses with high sensitivity is of fundamental importance to characterize and diagnose the biological systems. In regenerative medicine, the culture temperature and the thermogenic properties of stem-cells significantly affect the subsequent growth of regenerative cells and tissues, thereby preventing efficient growth of regenerative organs from stem cells. However, such thermogenic analyses at single cellular level have been elusive until now. Here we demonstrate microscope-based thermometry of adipose-tissue derived stem cells (ASCs [1]) taken from mice by using quantum sensors based on the electron spin resonance of color defect centers in fluorescent nanodiamonds (FNDs) [2]. ASCs are successfully labeled with FNDs while keeping the original ability for the proliferation and differentiation to osteocytes and adipocytes. The FND-labeled ASCs are measured to detect the intracellular temperature change. The FNDs act as nanoparticle thermometers in ASCs with the temperature dependence of - 63 kHz/oC with temperature accuracy of ± 0.9 oC and precision of ± 0.5 oC [3]. The present demonstration makes a new direction of the quantum sensor applications toward stem-cell research and regenerative medicine. [1] Yukawa et al., Adv. Drug Deliv. Rev. 95 , 2 (2015). [2] Fujiwara et al., Nanotech. 27, 455202 (2016): arXiv:1803.06179. (2018). [3] Manuscript in preparation.

Nanoparticles with various properties and functions are of growing interest for biomedical research, such as in vivo and in vitro sensors, imaging agents and delivery vehicles of therapeutics. An effective method to deliver nanoparticles into the intracellular environment is still a major challenge and critical to many biological studies. Current techniques, such as intracellular uptake, electroporation and microinjection, have different benefits and limitations (e.g., aggregation and endosomal degradation of nanoparticles, high cell mortality and low throughput). We demonstrate application of the well-established microelectrophoresis technique for the first time to deliver nanoparticles into target cells using fine-tipped micropipettes, which overcomes some of these delivery difficulties. Semiconductive quantum dots were selected as the nanoparticles in this study as they are widely used for biomedical imaging and sensing due to having functionalized surfaces suitable for bioconjugation, adaptable photophysical properties for multiplexed detection, and superior stability for longer investigation times. We developed a method to prepare monodisperse suspensions of quantum dots with average hydrodynamic diameter of ~20nm, which demonstrated sufficient colloidal stability to prevent aggregation and blockages in the tip of micropipettes during ejection while enabling sufficient electrical conductivity for ejection and recording electrical activity of cells. Fine-tipped glass micropipettes with an average tip inner diameter of 206 nm for ejection but less than 500 nm to minimize the cell membrane damage and cell distortion were successfully fabricated. Finally, quantum dots were successfully delivered into living human embryonic kidney cells using small electrical currents through fine-tipped glass micropipettes. The delivered quantum dots were found to stay monodispersed within the cells for 2 hours. We believe that microelectrophoresis technique may serve as a simple and general strategy for delivering a variety of biocompatible nanoparticles intracellularly in various biological systems.

Melanin is a natural pigment with myriad functions arising from its chemical structure including metal ion chelation, photo-protection, free radical quenching, and coloration. In humans, melanins can serve as a biomarker for melanoma and Parkinson’s disease. To exploit these properties, several groups have reported synthetic melanin nanoparticles (SMNPs) synthesized by the auto-oxidation of dopamine or L-3,4-dihydroxyphenylalanine to be used as contrast agents. We showed that gadolinium-loaded synthetic melanin nanoparticles (Gd(III)-SMNPs) exhibit up to a 40-fold enhanced photoacoustic signal intensity relative to synthetic melanin alone and higher than other metal-chelated SMNPs. This property makes these materials useful as dual labelling agents because Gd(III)-SMNPs also behave as magnetic resonance imaging (MRI) contrast agents. As a proof-of-concept, we used these nanoparticles to label human mesenchymal stem cells (hMSCs). Cellular uptake was confirmed with bright field optical and transmission electron microscopy. The Gd(III)-SMNP labeled stem cells expressed the stem cell surface markers CD73, CD90, and CD105 and continued to proliferate. The labeled stem cells were subsequently injected intramyocardially in mice, and the tissue was observed by photoacoustic and MR imaging. We found the photoacoustic signal increased as cell number increased (R2 = 0.96) indicating that such an approach could be employed to quantify stem cells with a limit of detection of 2.3 x 104 cells. This multimodal photoacoustic/MRI approach combines the excellent temporal resolution of photoacoustics with the anatomic resolution of MRI.

Nanoparticles play a vital role in the modern world, not only because of their reduced dimensions resulting in specific properties but also because they are promising building blocks for many complex nanostructures. Cerium oxide (CO) is a valuable material due to its unique properties resulting from its regenerative oxidation states. As it can exist in both the trivalent and tetravalent state, CO can act as a promising antioxidant, thereby absorbing harmful reactive oxygen species. In the present study, human lung epithelial (Beas-2B) cells were used to assess the toxicity, biocompatibility and anti-oxidant activity of CO nanoparticles. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and Live/Dead assays were performed to determine the cytotoxicity and biocompatibility of CO nanoparticles. Antioxidant property of CO nanoparticles was assessed by Reactive Oxygen Species (ROS) assay. MTT assay and Live/Dead assays showed no significant induction of cell death even at higher concentrations (100 μg/mL) upon exposure to Beas-2B cells. ROS assay revealed that CO nanoparticles significantly reduced the reactive oxygen species that contribute to the oxidative stress and inflammation leading to various disease conditions. Thus, CO nanoparticles have various biomedical applications including biosensors and cancer therapy. CO can be used in filters and ultra-violet absorbers in order to produce products such as catalytic converters and sunscreen. Furthermore, as CO nanoparticles have the ability to cross cell membranes due to their small size, they are effective for drug delivery. Authors: Prathima Prabhu Tumkur, Babu R. Lamani, Krishnan Prabhakaran, Joseph C. Hall and Govindarajan T. Ramesh.

We describe an approach for using the flagella axoneme as the basis for biological self-assembling protein nanoarrays. The axoneme is the insoluble protein core of the eukaryotic flagellum or cilium. By attaching a protein of interest to particular axonemal proteins, it is possible to exploit the intraflagellar transport system to incorporate those proteins into the axoneme as it assembles. Using the axoneme as a protein array confers several advantages, such as high protein loading capacity compared to other bioparticle systems; genetically programmed self-assembly without the need for any linking steps; single-step purification of particles without the need for cell lysis, allowing retention and re-use of biomass; and choice of isolating the particle as a membrane enclosed vesicle or as an exposed protein array. Here we test several potential axonemal proteins as adaptor proteins, using green fluorescent protein as a test case. We find that FAP20 is an ideal scaffold protein for this purpose in that it shows high incorporation and uniform localization. We verify that FAP20-GFP constructs are stably associated with the axoneme during purification and storage, that the GFP moiety can be released by protease cleavage, and that the flagellar array can be easily encapsulated in aqueous-oil emulsion droplets for use in microfluidic assays.

Invented in 2010, NanoCluster Beacons (NCBs) (1) are an emerging class of turn-on probes that show unprecedented capabilities in single-nucleotide polymorphism (2) and DNA methylation (3) detection. As the activation colors of NCBs can be tuned by a near-by, guanine-rich activator strand, NCBs are versatile, multicolor probes suitable for multiplexed detection at low cost. Whereas a variety of NCB designs have been explored and reported, further diversification and optimization of NCBs require a full scan of the ligand composition space. However, the current methods rely on microarray and multi-well plate selection, which only screen tens to hundreds of activator sequences (4, 5). Here we take advantage of the next-generation-sequencing (NGS) platform for high-throughput, large-scale selection of activator strands. We first generated a ~10⁴ activator sequence library on the Illumina MiSeq chip. Hybridizing this activator sequence library with a common nucleation sequence (which carried a nonfluorescent silver cluster) resulted in hundreds of MiSeq chip images with millions of bright spots (i.e. light-up polonies) of various intensities and colors. With a method termed Chip- Hybridized Associated Mapping Platform (CHAMP) (6), we were able to map these bright spots to the original DNA sequencing map, thus recovering the activator sequence behind each bright spot. After assigning an “activation score” to each “light-up polony”, we used a computational algorithm to select the best activator strands and validate these strands using the traditional in-solution preparation and fluorometer measurement method. By exploring a vast ligand composition space and observing the corresponding activation behaviors of silver clusters, we aim to elucidate the design rules of NCBs.

For bioimaging purposes, non-cytotoxic fluorescent labels, stable in biological media and capable of site-specific labeling are in upsurging demand. However, many fluorescent dyes with promising properties, such as fluorescent organic dyes, are poorly water-soluble and often lose their properties in water, limiting their use for bioapplications. The weak signals, poor photobleaching resistance, short fluorescence life time and low chemical stability are continuous challenges for the development of optimal fluorescent probes. The use of aqueous colloidal structures, such as nanovesicles, as nanocarriers for the loading of the organic dyes offers a promising strategy to overcome this limitation. As a matter of fact, we have engineered a new class of fluorescent organic nanoparticles (FONs) using thermodynamically stable nanovesicles named quatsomes (QS) [1-4]. QSs are new class of exceptionally stable small unilamellar vesicles with sizes smaller than 100nm, and formed by the self-assembly of sterols and quaternary ammonium surfactants. [5,6] Dye-loaded QSs can be prepared by a one-step method using compressed CO2, named depressurization of expanded liquid organic solution-suspension (DELOS-susp).[7] Indeed, it is a green technology leading to a formation of a highly homogenous dispersion of nanovesicles stables in an aqueous environment. The loading of water-insoluble carbocyanines dyes into QSs, has successfully proved the photostability of the obtained FONs in aqueous solutions, as well as, their valuable brightness [6]. They show excellent colloidal stability and structural homogeneity along with superior optical properties, in comparison with the fluorophores in solution. Dye-loaded QSs have enhanced optical properties, demonstrating the absence of non-fluorescent aggregates due to the Aggregation Caused Quenching (ACQ) effect, neither the formation of J- and H-aggregates was produced, in contrary to the well-known tendency of cyanines to aggregate [8]. Different methods for obtaining dye loaded nanoparticles were compared pointing the advantages of dye-loaded QS over other dye-based FONs, in terms of both, optical and colloidal properties. The effect of the dye loading on the physicochemical properties were studied as well as the brightness, showing higher brightness when dyes were located at the QS membrane. Moreover, experimental results were supported by molecular dynamics (MD) simulations which give information on the configuration of the dyes within the membrane. The potential of dye-loaded QSs for biological imaging was studied using a superresolution microscopy technique, the stochastic optical reconstruction microscopy (STORM). This study determine that dye-based QS are remarkable candidates as nanostructured probes for biological imaging, not only because of their photophysical properties but also, for their capabilities to be precisely decorated at their surfaces with targeting groups3 and to integrate small drugs or large biomolecules. All such benefits represent a certainly promising probe for bioimaging and, especially, for theragnostic nanomedicine. 1. Elizondo, E. et al. Influence of the Preparation Route on the Supramolecular Organization of Lipids in a Vesicular System. J. Am. Chem. Soc. 134, 1918–1921 (2012). 2. Ferrer-Tasies, L. et al. Quatsomes: Vesicles Formed by Self-Assembly of Sterols and Quaternary Ammonium Surfactants. Langmuir 29, 6519–6528 (2013). 3. Cabrera, I. et al. Multifunctional Nanovesicle-Bioactive Conjugates Prepared by a One-Step Scalable Method Using CO2-Expanded Solvents. Nano Lett. 13, 3766–3774 (2013). 4. Grimaldi, N. et al. Lipid-based nanovesicles for nanomedicine. Chem. Soc. Rev. 45, 6520–6545 (2016). 5. Silbaugh, D. A. et al. Highly Fluorescent Silicon Nanocrystals Stabilized in Water Using Quatsomes. Langmuir 33, 14366–14377 (2017). 6. Antonio, A. et al. Nanostructuring Lipophilic Dyes in Water Using Stable Vesicles, Quatsomes, as Scaffolds and Their Use as Probes for Bioimaging. Small 14, 1703851 (2018). 7. Ventosa, Nora; Veciana, Jaume; Sala, Santiago; Cano, M. Method for Obtaining Micro- and Nano-disperse systems. (2006). doi:WO/2006/079889 8. Gadde, S., Batchelor, E. K. & Kaifer, A. E. Controlling the Formation of Cyanine Dye H- and J-Aggregates with Cucurbituril Hosts in the Presence of Anionic Polyelectrolytes. Chem. – A Eur. J. 15, 6025–6031 (2009).

Red fluorescent proteins (RFPs) and genetically encoded biosensors built upon them present additional imaging wavelengths and can report from deeper layers of tissues compared to green fluorescent proteins (GFPs). However, the fluorescence quantum yield (QY) of the popular red variants such as mCherry and mPlum are low (0.1 – 0.2). Same is true for a number of red genetically encoded calcium indicators (GECIs) even in their bright state. The theoretically proposed physical mechanism of nonradiative relaxation involves intramolecular charge transfer (CT) from the phenolate to imidazolinone ring in the excited state that is coupled to the chromophore twisting about the methine bridge bonds. Such twisting can result in transition (hopping) between potential energy surfaces of the excited state and the ground state at their conical intersection. An alternative pathway (supported by our MD simulations) can involve accidental drops of the CT dark excited state (S2) energy below the bright S1 state in the course of temporal fluctuations of the protein surrounding. If the CT state governs nonradiative relaxation, strong local electric field directed from phenolate to imidazolinone can block this process resulting in the QY increase. We use two-photon spectroscopy to evaluate the components of the protein electric field in the plane of the RFP chromophore and demonstrate that in a series of RFPs nonradiative relaxation rate is correlated with the field component along the long chromophore axis. This provides useful guidelines for engineering brighter RFP probes.

Here we use the combination of fluorescent molecular rotors (FMR) and fluorescence lifetime imaging (FLIM) to image matrix viscosity in live cells. We use non-cancerous, epithelial human cornea (HCE) cells as a model system. We find that mitochondrial matrix viscosity varies between individual cells and even between individual organelles, showcasing the potential of viscosity imaging for cell biology purposes.

The fluorescent rotor probe thioflavin T (ThT) is used to investigate the presence of sheet structures in pheomelanin by studying the formation and disassembly of pheomelanin synthesized from L-cysteine, L-DOPA and the enzyme tyrosinase. Brown/black eumelanin and red/yellow pheomelanin are the most common forms of melanin with the former more extensively studied. The conclusion of decades of research is that both melanins possess ill-defined polymeric structures, which are reflected in their complex photophysics. The structural integrity and co-existence of these two forms has significant bearing on their functionality and indeed their spectroscopy offers possibilities as a melanoma biomarker. Extrinsic fluorescence probes have been little used to study melanin, but the evidence from ThT fluorescence is consistent with other techniques in finding that eumelanin’s constituent dihydroxyindoles form a stacked sheet structure akin to graphite. Whether or not such an equivalent sheet structure exists for pheomelanin’s constituent benzothiazines and benzothiazoles is unresolved. On investigating this possibility we find a sigmoidal increase in ThT fluorescence during pheomelanin synthesis is similar to that observed for eumelanin, implying a sheet structure. A red spectral shift in ThT fluorescence in pheomelanin and the emergence of a fluorescence decay component of ~ 5.5 ns, much longer than that of ThT, are interpreted in terms of sites wherein ThT is coupled to pheomelanin’s native structure. Such sites can act as fluorescent traps to which energy is funneled when melanin is excited and the composite fluorescence yield thus increased. However, we find the abundance of this decay component is significantly less for pheomelanin (6%) than eumelanin (11%), suggesting that ThT does not intercalate so readily in pheomelanin. This may reflect less sheet structure or tighter binding of pheomelanin’s sheets, consistent with its low fluorescence quantum yield. Disassembling pheomelanin upon raising pH provides further spectroscopic evidence that ThT is trapped in sheet-like aggregates of smaller oligomeric forms.

Of the reported ~20,000 skin disease related deaths in 2013, 30% were attributed to cutaneous infections, ulcers, wounds, and burns. Wound healing is currently visually assessed by physicians and commonly requires multiple clinical visits for frequent dressing changes. These are often painful and can further compromise tissue health along with increasing infection risks. Clinical workflows for skin wounds often include oxygenation assessment to help guide the course of treatment. However, the low oxygen perfusion intrinsic to these conditions renders standard-of-care blood oxygen saturation tools inaccurate. Transcutaneous oxygen measurements can overcome this issue, albeit with further complications such as time-consuming bedside calibrations and potentially painful application/removal of electrodes. We present a ‘SMART’ bandage approach that features clinically-validated oxygen sensing molecules embedded within a hydrogel for direct open wound oxygenation measurements. The hydrogel incorporates a phosphorescent red-emitting oxygen-sensing metalloporphyrin covalently attached to a green fluorescent reference dye. As phosphorescence is quenched via collisional energy exchange with molecular oxygen, phosphorescence intensity and lifetime can be used to quantify oxygenation. The emission is bright enough to be visualized by the naked eye, and its intensity was found to increase 10x in oxygen deprived environments (0 mmHg pO2) compared to room air (160 mmHg pO2). Additionally, the hydrogel is capable of swelling up to 400% of its original size in wound exudate while maintaining skin adhesion properties. Along with minimizing the time and materials required for re-dressing, this novel wound dressing has potential for mediating drug delivery and reducing unnecessary patient discomfort.

Last times carbon nanostructures based on carbon nanotubes and graphene are actively used in different fields of science and technic. Main problem of using these carbon nanostructures in water environment is that carbon nanostructures have a tendency to bond with each other via Van-der-Waals interaction. This issue can be resolved by the appending surface-active materials, such as phospholipids, into composite. We have carried out research on influence of phospholipids on stability of carbon composite. This researching was carried out by the increasing of the number of the phospholipids in the structure. Numerical counts were carried out on minimal structure cell of composite using AMBER energy potential with Berenson thermostat. Its concluded that stable of composite decreases by the increasing of number of the phospholipids.

A new website, centered on absorption and fluorescence spectra, has been designed for the broad community of members in the photosciences. Spectral data lie at the heart of the vast field of the photosciences, yet collections of such data are sparse, scattered and often in print rather than digital form. Because many if not most searches for photochemical data begin with individual spectra, the website should constitute a photosciences nexus. The database of <500 spectra can be accessed via text or by viewing molecular structures. The spectral data on the website are identical with those in the database associated with the software program PhotochemCAD, but only the latter contains the rich trove of companion references to the originating scientific literature. PhotochemCAD, which contains modules for diverse calculations germane to the photosciences, can be freely downloaded from the new website. To develop a community of users in the photosciences, a curated and validated set of email addresses of photoscientists has been generated from the primary photochemistry literature since 2004. The literature surveyed (19 journals, <45,000 articles) encompasses the flagship publications of 15 scholarly societies. The present work represents a step toward fulfilling the long-term ambition of assembling all known spectral data worldwide, from print and digital sources, in one carefully curated collection of digital data in a readily accessible site. The advances should broaden awareness and increase availability of spectra for diverse studies in the field of photosciences, which encompasses art, astrobiology, biology, chemistry, ecology, engineering, medicine, physics, textiles, and zoochromy.

The effect of different concentrations of K⁺, Na⁺, Ca²⁺, Ni²⁺, Al³⁺ and Fe³⁺ ions on surface-active substance monolayer stability has been studied using molecular mechanics method. For numerical calculations, energy potential Amber was used. Arachidic acid was chosen as a surface-active substance for monolayer formation because it is insoluble in water at normal conditions. Energy stability values representing system stability was calculated for different ion concentrations. It is established that the most stable system is formed by trivalent metal ions and that system stability decreases together with ionic charge. For each type of ions, a concentration value corresponding to most optimal stability was found with further increase of ion concentration leading to decrease of stability.

Matrix metalloproteinases (MMPs) plays an important role in the regulation of invasion and metastasis of tumor cells. In this work, an inhibitory peptide of MMP-2 and MMP-9 was conjugated to gold nanoparticle as an inhibitor to MMP-2 and MMP-9 to improve chemical and physical stability. The results were proved that this nanoparticle showed inhibition on the enzymatic activity of MMP-2 and MMP-9, and significantly inhibited the migration and invasion of tumor cells in vitro. This gold nanoparticle can be functioned as an inhibitor with a more pronounced inhibitory effect on invasion and metastasis of tumor.

The most important problem of the nowadays is the short of the clear water. We suppose the using of the novel material – the pillared graphene for resolving this problem. The pillared graphene exceeds already used in the sorption the frame carbon materials in the values of the specific surface area. One of the most important specified requirements for sorbent is a mechanical strength. It is known, that mechanical strength heavily depends on the pillared graphene’s geometry: the lengths and the diameter of the carbon nanotubes. In this paper, we have carried out theoretical research of the depending Young’s modulus of the finite size pillared graphene based on the zigzag-CNT on his geometry. The composite, which has the most strength, is recommended for using in the water purification.

The paper performs multiscale modeling of interaction between hybrid patch and blood vessels as well as patch with heart tissue by finite element method. Patch represented 3-dimensional cellular engineering structure consisted of three layers: carbon nanotube carcass, lipids of albumin and collagen and the aminosugar of chitosan. It was found that maximum stresses were observed in the contact area between media and the advent layers. It was found that in diastole the maximal values of patch displacement as well as the greatest stresses were concentrated in the area of contact between heart and patch.

At present, nanobiomedicine is one of the most actively and successfully developing areas of nanotechnology. One of the important areas of modern biomedicine is the creation of a new generation of implants that are not rejected by the human immune system. Carbon nanotubes are widely used to solve this problem. 3D wireframe composite nanomaterials are created on the basis of carbon nanotubes under the action of an electric field of pulsed or continuous laser radiation. The presence of such framework creates conditions for the self-organization of the cellular material for biological tissues. Promising biomaterials for the creation of bulk nanocomposites are albumin and collagen. Albumin is a protein-transporter in the blood for many substances, and collagen is the basis of the intercellular substance of the connective tissue of the tendons, bone, cartilage, and skin. Both proteins belong to the group of natural biopolymers used in tissue engineering for the purpose of regenerating neurons. In this work, we constructed an atomistic model of a mixture of single-walled carbon nanotubes in a protein matrix based on albumin and collagen, taking into account the curvature, twisting, overlapping, and other topological features of carbon nanotubes. Conditions for the formation of an energy-stable nanocarbon framework with protein filling, promising for use in cell engineering, are revealed using the methods of atomistic and coarsegrained molecular dynamic modeling.

This work is devoted to the development of a methodology for modeling a multilayer and multi-component biostructure from individual layers for restoration of tissues of heart and blood vessels. Structural elements of considered complex bioconstruction are alternating layers of carbon nanotubes and albumin, carbon nanotubes and collagen, and also carbon nanotubes and chitosan. The atomistic and coarse-grained models of individual layers of structures are constructed, and its assembly is carried out in the presence of water using molecular dynamics. The binding energies of the individual layers with each other are calculated to create a subsequent multi-layer elastic structure.

In this paper, we investigated absorption of electromagnetic waves in the infrared (IR) visible- ultraviolet (UV) ranges for a 3D-wireframe material based on carbon nanotubes (CNTs) and albumin using the methods of mathematical modeling and revealed the regularities of absorption on the wavelengths and chirality of extended nanotubes. We investigated influence of electromagnetic field on single-walled CNTs (SWCNTs) in the protein matrix of albumin, when the CNTs contain defects. Investigations of dependence of the absorption on various types of defect and number of defects for tubes with different types of conductivity in the protein matrix of albumin were carried out.

Immune checkpoint blockade (ICB) has shown unprecedented clinical success in treatment of cancer. However, not all patients show adequate response, and the treatment can lead to a broad range of adverse effects. Therefore, early identification of potential responders to therapy, using non-invasive means, is a critical challenge for improving ICB. Herein, we engineered anti-Programmed Death Ligand 1 (aPDL1) nanoparticles with enhanced ICB immunotherapy efficacy. Using a mouse model for colon cancer, we show that the nanoparticles accumulated, penetrated and efficiently prevented tumor growth. Moreover, we found a direct correlation between the amount of nanoparticle accumulation within the tumor at 48 hours, as determined by CT, and the therapeutic response. This enabled subject stratification as potential responders or non-responders, at an early time point. Thus, by integrating prognostic and ICB-based therapeutic functions into one nanoparticle, we obtained a straightforward approach for potential imageguided stratification of cancer patient subpopulations.