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The phosphoinositide 3-kinase (PI3K) pathway playing an important role in cell proliferation, growth, and survival is one of the most frequently dysregulated pathways in cancer. However, PI3K inhibitors, used as a monotherapy, have shown limited therapeutic efficacies and high rates of side effects from acquired resistance to PI3K inhibition via feedback loop-mediated pathway reactivation and poor tolerability of small-molecule inhibitors. Here, we proposed a multi-targeting siRNA delivery system using polymerized siRNA-based nanoparticle formulations (Msi-NPs) as a PI3K-targeted anticancer therapy for simultaneous ablation of Rac1 and p110β-subunit of PI3K linked by a Rac-PI3K positive feedback loop. Msi-NPs could self-assemble from polymerized siRNAs targeting Rac1 and p110β together with thiolated glycol chitosan. The combinatory inhibition of Rac1 and p110β successfully inhibited the PI3K signaling pathway in PI3K tumor suppressor phosphatase and tensin homolog (PTEN) deficient prostate cancer cells, resulting in significant delays in cell proliferation and migration. The Msi-NP delivery system can provide an alternative therapeutic strategy to overcome the challenges in PI3K inhibitor monotherapy.

The phosphoinositide 3-kinase (PI3K) and RAS signaling pathways are frequently co-activated and altered during oncogenesis. Owing to their regulatory cross-talk, the early attempts of targeting only one pathway have mostly ended up promoting the development of drug resistance. Here, we propose using small interfering RNA (siRNA) therapeutics to directly target the undruggable KRAS (siKRAS) in combination with the pan-PI3K inhibitor GDC-0941 (GDC) to simultaneously block both PI3K and RAS signaling, thereby exerting synergistic anti-tumor effects on ovarian cancers with PTEN deficiency and KRAS(G12D) mutation. For successful delivery of siKRAS, tGC/psi—nanoparticle formulation of polymerized siRNA and thiol-modified glycol chitosan nanoparticle—was used for KRAS specific inhibition in vitro and in vivo. GDC or siKRAS monotherapy each impede downstream signaling, leading to some delay in cell proliferation and migration. When combined, however, they engender much higher inhibition of PI3K signaling and stimulation of apoptosis in an ovarian allograft model compared to monotherapies. Our results show the feasibility of developing new combination strategies for the management of multiple oncogenic mutations activating PI3K and RAS signaling.

Cryopyrin-associated periodic syndrome (CAPS) is an inherited autoinflammatory disease caused by a gain-of-function mutation in NLRP3. Although CAPS patients frequently suffer from sensorineural hearing loss, it remains unclear whether CAPS-associated mutation in NLRP3 is associated with the progression of hearing loss.We generated a mice with conditional expression of CAPS-associated NLRP3 mutant (D301N) in cochlea-resident CX3CR1 macrophages and examined the susceptibility of CAPS mice to inflammation-mediated hearing loss in a local and systemic inflammation context.Upon lipopolysaccharide (LPS) injection into middle ear cavity, NLRP3 mutant mice exhibited severe cochlear inflammation, inflammasome activation and hearing loss. However, this middle ear injection model induced a considerable hearing loss in control mice and inevitably caused an inflammation-independent hearing loss possibly due to ear tissue damages by injection procedure. Subsequently, we optimized a systemic LPS injection model, which induced a significant hearing loss in NLRP3 mutant mice but not in control mice. Peripheral inflammation induced by a repetitive low dose of LPS injection caused a blood-labyrinth barrier disruption, macrophage infiltration into cochlea and cochlear inflammasome activation in an NLRP3-dependent manner. Interestingly, both cochlea-infiltrating and -resident macrophages contribute to peripheral inflammation-mediated hearing loss of CAPS mice. Furthermore, NLRP3-specific inhibitor, MCC950, as well as an interleukin-1 receptor antagonist significantly alleviated systemic LPS-induced hearing loss and inflammatory phenotypes in NLRP3 mutant mice.Our findings reveal that CAPS-associated NLRP3 mutation is critical for peripheral inflammation-induced hearing loss in our CAPS mice model, and an NLRP3-specific inhibitor can be used to treat inflammation-mediated sensorineural hearing loss.National Research Foundation of Korea Grant funded by the Korean Government and the Team Science Award of Yonsei University College of Medicine.

Rosacea is a chronic inflammatory skin disease characterized by immune response–dependent erythema and pustules. Although the precise etiology of rosacea remains elusive, its pathogenesis is reportedly associated with an increased level of antimicrobial peptide LL-37. However, molecular mechanisms underlying the progression of rosacea via LL-37 remain poorly understood. Here, we examined the potential role of LL-37 in rosacea-like skin inflammatory phenotypes at a molecular level. Our in vitro data demonstrated that LL-37 promotes NLRP3-mediated inflammasome activation in lipopolysaccharide-primed macrophages, indicated by the processing of caspase-1 and IL-1β. LL-37 was internalized into the cytoplasm of macrophages through P2X7 receptor–mediated endocytosis. Intracellular LL-37 triggered the assembly and activation of NLRP3-ASC inflammasome complex by facilitating lysosomal destabilization. Consistent with these in vitro results, intradermal LL-37 administration induced in vivo caspase-1 activation and ASC speck formation in the skin of Nlrp3-expressing, but not in Nlrp3-deficient, mice. Intradermal injection of LL-37 elicited profound recruitment of inflammatory Gr1+ cells and subsequent skin inflammation. However, LL-37–induced rosacea-like skin inflammation was significantly abrogated in Nlrp3-deficient mice. Furthermore, an NLRP3-specific inhibitor, MCC950, markedly reduced LL-37–triggered rosacea-like phenotypes. Taken together, our findings clearly indicate that NLRP3 inflammasome activation plays a crucial role in LL-37–induced skin inflammation and rosacea pathogenesis.

Thrombosis is an important pathophysiologic phenomenon in various cardiovascular diseases, which can lead to oxygen deprivation and infarction of tissues by generation of a thrombus. Thus, direct thrombus imaging can provide beneficial in diagnosis and therapy of thrombosis. Herein, we developed thrombin-activatable fluorescent peptide (TAP) incorporated silica-coated gold nanoparticles (TAP-SiO2@AuNPs) for direct imaging of thrombus by dual near-infrared fluorescence (NIRF) and micro-computed tomography (micro-CT) imaging, wherein TAP molecules were used as targeted thrombin-activatable peptide probes for thrombin-specific NIRF imaging. The freshly prepared TAP-SiO2@AuNPs had an average diameter of 39.8 ± 2.55 nm and they showed the quenched NIRF signal in aqueous condition, due to the excellent quenching effect of TAP molecules on the silica-gold nanoparticle surface. However, 30.31-fold higher NIRF intensity was rapidly recovered in the presence of thrombin in vitro, due to the thrombin-specific cleavage of quenched TAP molecules on the gold particle surface. Furthermore, TAP-SiO2@AuNPs were successfully accumulated in thrombus by their particle size-dependent capturing property, and they presented a potential X-ray absorption property in a dose-dependent manner. Finally, thrombotic lesion was clearly distinguished from peripheral tissues by dual NIRF/micro-CT imaging after intravenous injection of TAP-SiO2@AuNPs in the in situ thrombotic mouse model, simultaneously. This study showed that thrombin-activatable fluorescent peptide incorporated silica-coated gold nanoparticles can be potentially used as a dual imaging probe for direct thrombus imaging and therapy in clinical applications.

The effective chemotherapeutic drug, doxorubicin (DOX), elicits immunogenic cell death (ICD) and additional anticancer immune responses during chemotherapy. However, it also induces severe side effects and systemic immunosuppression, hampering its wide clinical application. Herein, we constructed cancer-activated DOX prodrug by conjugating the cathepsin B-cleavable peptide (Phe-Arg-Arg-Gly, FRRG) to a doxorubicin (DOX), resulting in FRRG-DOX that self-assembled into cancer-activated DOX prodrug nanoparticles (CAP-NPs). The resulting CAP-NPs were further stabilized with the FDA-approved compound, Pluronic F68. CAP-NPs formed stable prodrug nanoparticles and they were specifically cleaved to cytotoxic DOX molecules only in cathepsin B-overexpressing cancer cells, inducing a cancer cell-specific cytotoxicity. In particular, the CAP-NPs induced ICD through cathepsin B-cleavage mechanism only in targeted cancer cells in vitro. In colon tumor-bearing mice, selectively accumulated CAP-NPs at tumors enhanced antitumor immunity without DOX-related severe toxicity, inflammatory response and systemic immunosuppression. Moreover, cytotoxicity against immune cells infiltrated into tumor microenvironment was significantly reduced compared to free DOX, leading to increased response to checkpoint inhibitor immunotherapy. The combinatorial treatment of CAP-NPs with anti-PD-L1 exhibited high rate of complete tumor regression (50%) compared to free DOX with anti-PD-L1. Concurrently, DOX-related side effects were greatly reduced during chemoimmunotherapy. Collectively, our results suggest that cancer-activated DOX prodrug nanoparticles provide a promising approach to increase clinical benefit by inducing an immune response preferentially only to targeted cancer cells, not to normal cells and immune cells, and potentiates checkpoint inhibitor immunotherapy.

Nanoparticles have resulted in great progress in biomedical imaging and targeted drug delivery in cancer theranostics. To develop nanoparticles as an effective carrier system for therapeutics, chemical structures and physicochemical properties of nanoparticle may provide a reliable means to predict the in vitro characteristics of nanoparticles. However, in vivo fates of nanoparticles, such as pharmacokinetics and tumor targeting efficiency of nanoparticles, have been difficult to predict beforehand. To predict the in vivo fates of nanoparticles in tumor-bearing mice, differences in physicochemical properties and in vitro cancer cell/macrophage uptake of 5 different nanoparticles with mean diameter of 200-250nm were comparatively analyzed, along with their circulation in adult zebrafish. The nanoparticles which showed favorable cellular uptake by macrophages indicated high unintended liver accumulation in vivo, which is attributed to the clearance by the reticuloendothelial system (RES). In addition, blood circulation of nanoparticles was closely correlated in adult zebrafish and in mice that the zebrafish experiment may elucidate the in vivo behavior of nanoparticles in advance of the in vivo experiment using mammal animal models. This comparative study on various nanoparticles was conducted to provide the basic information on predicting the in vivo fates of nanoparticles prior to the in vivo experiments.

A suitable liquid chromatography tandem mass spectrometry (LC-MS/MS) method is required to determine pelubiprofen and its active metabolite, trans-alcohol (M-D), in human plasma for pharmacokinetic studies of pelubiprofen preparations. After one-step liquid-liquid extraction (LLE) using methyl tert-butyl ether (MTBE), pelubiprofen, M-D, and tolbutamide (the internal standard, IS) were eluted from a Capcellpak C18 ACR column using a gradient mobile phase consisting of 0.1% formic acid in water and acetonitrile at a flow rate 0.35mL/min. The achieved lower limits of quantitation (LLOQ) of pelubiprofen and M-D were both 15ng/mL (S/N>10) and the standard calibration curves for pelubiprofen and M-D were linear (correlation coefficients >0.99) over the studied concentration range (15-2000ng/mL). Intra- and inter-day precisions were within 7.62% for all analytes and the deviation of assay accuracies was within ±13.23%. The developed method was successfully applied to a pharmacokinetic study of pelubiprofen in healthy Korean male volunteers.

The concept of personalized medicine has recently emerged as a promising way to address unmet medical needs. Due to the limitations of standard diagnostic and therapeutic strategies, the disease treatment is moving towards tailored treatment for individual patients, considering the inter-individual variability in therapeutic response. Theranostics, which involves the combination of therapy and diagnostic imaging into a single system, may fulfill the promise of personalized medicine. By integrating molecular imaging functionalities into therapy, theranostic approach could be advantageous in therapy selection, treatment planning, objective response monitoring and follow-up therapy planning based on the specific molecular characteristics of a disease. Although the field of therapy and imaging of its response have been independently developed thus far, developing imaging strategies can be fully exploited to revolutionize the theranostic systems in combination with the therapy modality. In this review, we describe the recent advances in molecular imaging technologies that have been specifically developed to evaluate the therapeutic efficacy for theranostic purposes.

Matrix metalloproteinase (MMP)-2 and MMP-9 have been known to play the role of essential mediators in angiogenesis. Non-invasive in vivo imaging approach using imaging probes is a potential method of detecting MMP activity in living animals, wherein imaging probes must include the characteristics of non-toxicity, specific targetability, and reasonable signal intensity. Here, we developed MMP-specific and self-quenched human serum albumin (HSA)-based (MMP-HSA) nanoprobes for non-invasive optical imaging of MMP activity during angiogenesis in the mouse hindlimb ischemia model. MMP-specific fluorogenic peptide probes, which were self-quenched with a near-infrared fluorophore and a quencher, were covalently conjugated to HSA (MMP-HSA nanoprobes). MMP-HSA nanoprobes formed stable nanoparticle structures of approximately 36 nm in diameter. Strongly self-quenched MMP-HSA nanoprobes boosted intense fluorescence signals in the presence of MMP-2 and MMP-9. Furthermore, MMP-HSA nanoprobes showed no cytotoxicity in cell culture. Importantly, intravenous injection of MMP-HSA nanoprobes provided longer blood half-life and successful non-invasive optical imaging of MMP activity during angiogenesis in the mouse hindlimb ischemia model. In addition, the MMP activity visualized by MMP-HSA nanoprobes was consistent with the results of zymography, Western blot, and immunohistochemistry. MMP-HSA nanoprobes may be useful for monitoring of the initial process of angiogenesis through non-invasive MMP imaging.

Theragnostic nanoparticles (NPs) contain diagnostic and therapeutic functions in one integrated system, enabling diagnosis, therapy, and monitoring of therapeutic response at the same time. For diagnostic function, theragnostic NPs require the inclusion of noninvasive imaging modalities. Among them, optical imaging has various advantages including sensitivity, real-time and convenient use, and non-ionization safety, which make it the leading technique for theragnostic NPs. For therapeutic function, theragnostic NPs have been applied to chemotherapy, photodynamic therapy, siRNA therapy and photothermal therapy. In this review, we present a recent progress reported in the development and applications of theragnostic NPs for cancer therapy. More specifically, we will focus on theragnostic NPs related with optical imaging, highlighting promising strategies based on optical imaging techniques.

Summary Recent progress in bio and nanotechnology enables the development of various nanoprobes for biomedical imaging. The detection and imaging of specific changes in biological microenvironments play key roles in many fields such as biological mechanism study, drug screening, diagnosis of many diseases, and monitoring of therapeutic responses. Especially to obtain fine images in living systems, there are many requirements such as stability in complex condition, efficient accumulation in target site, and high sensitivity to the target molecule. For this purpose, many researchers have developed a number of nano-size probes sensitive to the external changes which are valuable from biomedical point of view. Herein, we will review the on-going challenges of developing novel nanoprobes to detect chemical or biological changes such as enzyme, oxygen, and pH, and applying them to biomedical imaging in living systems.

A rapid and simple procedure was developed for the determination of cephradine in human plasma using liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). After trichloroacetic acid (TCA) precipitation of proteins from plasma samples, cephradine and cefaclor (the internal standard; IS) were eluted on a CN column. The isocratic mobile phase used consisted of acetonitrile-water-formic acid (25:75:0.1, v/v/v). Cephradine and the IS were both detected in multiple reaction monitoring (MRM) mode at the transitions: m/z 350.0 --> 90.8 for cephradine and m/z 368.1 --> 106.0 for the IS, respectively. The calibration curve was linear over the concentration range from 0.05 to 50 microg/ml, and correlation coefficients were greater than 0.996. The coefficient of variation of assay precision was less than 9.36%, and its accuracy ranged from 87.92% to 111.16%. The chromatographic run time for each plasma sample was less than 3 min. The developed method was successfully applied to a bioequivalence study of cephradine in healthy male volunteers.

Neovascularization may improve cardiac function and prevent further scar tissue formation in infarcted myocardium. A number of studies have demonstrated that bone marrow-derived cells have the potential to induce neovascularization in ischemic tissues. In this study, we hypothesized that implantation of bone marrow mononuclear cells (BMMNCs) using injectable fibrin matrix further enhances neovascularization in infarcted myocardium compared to BMMNC implantation without matrix. To test this hypothesis, infarction was induced in rat myocardium by cryoinjury. Three weeks later, rat BMMNCs were mixed with fibrin matrix and injected into the infarcted myocardium. Injection of either BMMNCs or medium alone into infarcted myocardium served as controls. Eight weeks after the treatments, histological analyses indicated that implantation of BMMNCs using fibrin matrix resulted in more extensive tissue regeneration in the infarcted myocardium compared to BMMNC implantation without matrix. Examination with fluorescence microscopy revealed that cells labeled with a fluorescent dye prior to implantation survived in the infarcted myocardium at 8 weeks of implantation. Importantly, implantation of BMMNCs using fibrin matrix resulted in much more extensive neovascularization in infarcted myocardium than BMMNC implantation without matrix. The microvessel density in infarcted myocardium was significantly higher (p0.05) when BMMNCs were implanted using fibrin matrix (350 +/- 22 microvessels/mm2) compared to BMMNC implantation without matrix (262 +/- 13 microvessels/mm2) and medium injection (76 +/- 9 microvessels/mm2). In addition, average internal diameter of microvessels was significantly larger (p0.05) in BMMNC implantation with fibrin matrix group (14.6 +/- 1.2 microm) than BMMNC implantation without matrix group (10.2 +/- 0.7 microm) and medium injection group (7.3 +/- 0.5 microm). These results suggest that fibrin matrix could serve as a cell implantation matrix that enhances neovascularization efficacy for myocardial infarction treatment.