Suspensory ligaments and muscle tissue backing the radioulnocarpal mutual

MFLI quantitatively reports on nanoscale interactions via lifetime-sensing of Förster Resonance Energy Transfer (FRET) in live, intact animals. Hence, MFLI FRET acts as a direct reporter of receptor dimerization and target engagement via the measurement of the fraction of labeled-donor entity undergoing binding to its respective receptor. MFLI is expected to greatly impact preclinical imaging and also adjacent fields such as image-guided surgery and drug development.Aminolevulinic acid (ALA) has been clinically used as an intraoperative fluorescence probe for protoporphyrin IX (PpIX) fluorescence-guided tumor resection and a PDT agent for cancer treatment. Although tumor tissues often show increased ALA-PpIX fluorescence compared with normal tissues, which enables the use of ALA for tumor imaging and targeting, weak tumor PpIX fluorescence as well as the heterogeneity in tumor fluorescence severely limits its clinical application. Intracellular PpIX in tumor cells is reduced by two major mechanisms, efflux by ATP-binding cassette (ABC) transporters such as ABCG2 and bioconversion to form heme by ferrochelatase (FECH) in the heme biosynthesis pathway. Targeting these two predominant PpIX-reducing mechanisms for the enhancement of ALA-PpIX have yielded a plethora of promising results and stimulated the clinical exploration of these enhancement strategies. Here we describe our methods of evaluating chemicals for the inhibition of ABCG2 transporter and FECH activity. Our goal is to further encourage research and development of novel ABCG2 and FECH inhibitors and promote a rational use of these inhibitors to optimize ALA-based tumor detection and treatment.Photodynamic therapy (PDT) is an emerging treatment option for cancer. In PDT, photosensitizers are delivered to tumors and stimulated by light to generate reactive oxygen species (ROS)-most importantly singlet oxygen (1O2)-to damage tumor cells or induce tissue ischemia. PDT is associated with a low level of systemic toxicity because photosensitizers are usually pharmaceutically inactive in the dark and photoirradiation is applied only to tumor areas in the procedure. Additionally, PDT can be applied repeatedly without cumulative toxicity or incurring resistance, and may stimulate systemic anti-tumor immunity. However, PDT's clinical use has been restricted due to the limited penetration of visible light through tissues. X-rays possess superior tissue penetration capability and are exploited in X-ray-induced photodynamic therapy to overcome this limitation. Herein we have demonstrated this principle with a novel LiGa5O8Cr (LGOCr)-based nanoscintillator which emits near-infrared X-ray luminescence to both guide external beam therapy and induce PDT with the photosensitizer (2,3-naphthalocyanine) encapsulated in a mesoporous silica shell of the nanoscintillator.There is a growing need to develop tumor targeting agents for aggressive cancers. Aggressive cancers frequently relapse and are resistant to various therapies. Cancer stem cells (CSCs) are believed to be the cause of relapse and the aggressive nature of many cancers. Targeting CSCs could lead to novel diagnostic and treatment options. Bacteriophage (phage) display is a powerful tool developed by George Smith in 1985 to aid in the discovery of CSC targeting agents. Phage display selections are typically performed in vitro against an immobilized target. There are inherent disadvantages with this technique that can be circumvented by performing phage display selections in vivo. However, in vivo phage display selections present new challenges. A combination of both in vitro and in vivo selections, however, can take advantage of both selection methods. In this chapter, we discuss in detail how to isolate a CSC like population of cells from an aggressive cancer cell line, perform in vivo and in vitro phage display selections against the CSCs, and then characterize the resulting phage/peptides for further use as a diagnostic and therapeutic tool.Pediatric hydrocephalus is a debilitating condition that affects an estimated 1-2 in 1000 newborns, and there is no cure. A traditional treatment is surgical insertion of a shunt system which was designed 50 years ago, and minimal ensuing progress has been made in improving the failure rate of these devices resulting in the need for multiple brain surgeries during an affected child's lifetime for shunt replacement. A first step toward decreasing the failure rate is to optimize the ventricular catheter component of the shunt to minimize its propensity for obstruction. Given the many geometric properties and patient specific in vivo conditions needed to characterize the fluid dynamics affecting ventricular catheter performance, validated computational simulation is an efficient method to rapidly explore and evaluate the effects of this large parameter space to inform improved design and to investigate patient specific shunt performance. This chapter provides the details on how to build a computational model of a ventricle and implanted catheter, analyze the fluid dynamics through an obstructed catheter, and postprocess the results to predict catheter performance for varying geometry and in vivo conditions.Although the use of stem cell therapy for central nervous system (CNS) repair has shown considerable promise, it is still limited by the immediate death of a large fraction of transplanted cells owing to cell handling procedures, injection stress and host immune attack leading to poor therapeutic outcomes. Scaffolding cells in hydrogels is known to protect cells from such immediate death by shielding them from mechanical damage and by averting an immune attack after transplantation. Implanted hydrogels must eventually degrade and facilitate a safe integration of the graft with the surrounding host tissue. Hence, serial monitoring of hydrogel degradation in vivo is pivotal to optimize hydrogel compositions and overall therapeutic efficacy of the graft. We present here methods and protocols to use chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) as a non-invasive, label-free imaging paradigm to monitor the degradation of composite hydrogels made up of thiolated gelatin (Gel-SH), thiolated hyaluronic acid (HA-SH), and poly (ethylene glycol) diacrylate (PEGDA), of which the stiffness and CEST contrast can be fine-tuned by simply varying the composite concentrations and mixing ratios. By individually labeling Gel-S and HA-S with two distinct near-infrared (NIR) dyes, multispectral monitoring of the relative degradation of the components can be used for long-term validation of the CEST MRI findings.Neutrophils rapidly accumulate at sites of inflammation, including biomaterial implantation sites, where they can modulate the microenvironment toward repair through a variety of functions, including superoxide generation, granule release, and extrusion of neutrophil extracellular traps (NETs). NETs are becoming increasing implicated as a central player in the host response to a biomaterial, and as such, there is a need for reliable in vitro methods to evaluate the relative degree of NETs and quantify NETs on the surface of biomaterials. Such methods should be relatively high throughput and minimize sampling bias. In this chapter, we describe two procedures, (1) fluorescent image analysis and (2) a NETs-based ELISA, both of which have been specifically optimized to quantify NETs generated from human neutrophils on electrospun polydioxanone templates. Both methods are valid and also compatible with tissue culture plastic, but have a variety of advantages and disadvantages. Therefore, both methods can be used to concomitantly study NETs on the surface of a biomaterial. Finally, while these methods were developed for electrospun templates in a 96-well cell culture plate, they may be easily adapted to a large scale and for other biomaterials, including but not limited to metallics, ceramics, and natural and synthetic polymers.A novel approach to address the clinical issue of cell response to wear and corrosion debris from metal orthopedic implants consists of combining cell culturing with wear and corrosion debris generation. A biotribometer equipped with a three-electrode electrochemical chamber operates inside a CO2 incubator. Cells are cultured at the bottom of the chamber. A ceramic ball (hip implant head) is pressed against a metal disc under a constant load, and set in reciprocating rotation. An anodic electrochemical potential can be applied to a metal disc for accelerated corrosion conditions, or the free potential may be monitored.Measurements of gravimetric and volumetric material loss of the metal disc postwear provide quantitative information that can be put in relation to biological assays (e.g., cell viability and secretion of proinflammatory cytokines). This approach allows for the comparison of candidate metals potentially undergoing tribocorrosion in clinical use. The approach allows to identify the effect of any metastable debris, likely active in vivo.Biodegradable nanocomposite scaffolds have been used for bone regeneration by serving as provisional template with optimal mechanical and biological properties analogous to native extracellular matrix (ECM). Their unique biomimicking structures aid in cell adhesion, differentiation, and proliferation with similar characteristics of the cells' ECM. Researchers are currently faced with a roadblock on ways to develop emerging process techniques to make biodegradable nanocomposite scaffolds and imitate these in exact synthetic ECM environments. This chapter particularly focuses on the technique of electrospinning for fabricating synthetic bone substitute materials for promoting bone repair and regeneration.Although bone tissue allografts and autografts aremoften used as a regenerative tissue during the bone healing, their availability, donor site morbidity, and immune response to grafted tissue are limiting factors their more common usage. Tissue engineered implants, such as acellular or cellular polymeric structures, can be an alternative solution. A variety of scaffold fabrication techniques including electrospinning, particulate leaching, particle sintering, and more recently 3D printing have been used to create scaffolds with interconnected pores and mechanical properties for tissue regeneration. Simply combining particle sintering and molecular self-assembly to create porous microstructures with imbued nanofibers to produce micronanostructures for tissue regeneration applications. Natural polymers like polysaccharides, proteins and peptides of plant or animal origin have gained significant attention due to their assured biocompatibility in tissue regeneration. However, majority of these polymers are water nitor adhesion, proliferation, migration, differentiation, extracellular matrix (ECM) secretion in promoting bone healing. In this chapter we will provide a detailed protocol on the creation of micronanostructured CA-collagen scaffolds and their characterization for bone tissue engineering using human mesenchymal stem cells.This chapter describes methods to engineer human lymphatic microvessels in vitro and to assess their fluid and solute drainage capacities. The lymphatics are formed within micropatterned type I collagen gels that contain a blind-ended channel for the growth of lymphatic endothelial cells. Because the vessels have one blind end and one open end each, they mimic the terminal structure of the native lymphatic microvascular tree. The solute drainage rates that are measured from the engineered lymphatics in vitro can be directly compared with published results from intact vessels in vivo. Practical considerations to increase the accuracy of the drainage assays are discussed.