Near-infrared duocarmycin photorelease from a Treg-targeted antibody-drug conjugate improves efficacy of PD-1 blockade in syngeneic murine tumor models.

Regulatory T cells (Tregs) play a crucial role in mediating immunosuppression in the tumor microenvironment. Furthermore, Tregs contribute to the lack of efficacy and hyperprogressive disease upon Programmed cell death protein 1 (PD-1) blockade immunotherapy. Thus, Tregs are considered a promising therapeutic target, especially when combined with PD-1 blockade. However, systemic depletion of Tregs causes severe autoimmune adverse events, which poses a serious challenge to Treg-directed therapy. Here, we developed a novel treatment to locally and predominantly damage Tregs by near-infrared duocarmycin photorelease (NIR-DPR). In this technology, we prepared anti-CD25 F(ab')2 conjugates, which site-specifically uncage duocarmycin in CD25-expressing cells upon exposure to NIR light. In vitro, CD25-targeted NIR-DPR significantly increased apoptosis of CD25-expressing HT2-A5E cells. When tumors were irradiated with NIR light in vivo, intratumoral CD25+ Treg populations decreased and Ki-67 and Interleukin-10 expression was suppressed, indicating impaired functioning of intratumoral CD25+ Tregs. CD25-targeted NIR-DPR suppressed tumor growth and improved survival in syngeneic murine tumor models. Of note, CD25-targeted NIR-DPR synergistically enhanced the efficacy of PD-1 blockade, especially in tumors with higher CD8+/Treg PD-1 ratios. Furthermore, the combination therapy induced significant anti-cancer immunity including maturation of dendritic cells, extensive intratumoral infiltration of cytotoxic CD8+ T cells, and increased differentiation into CD8+ memory T cells. Altogether, CD25-targeted NIR-DPR locally and predominantly targets Tregs in the tumor microenvironment and synergistically improves the efficacy of PD-1 blockade, suggesting that this combination therapy can be a rational anti-cancer combination immunotherapy.

Method To Diversify Cyanine Chromophore Functionality Enables Improved Biomolecule Tracking and Intracellular Imaging.

Heptamethine indocyanines are invaluable probes for near-infrared (NIR) imaging. Despite broad use, there are only a few synthetic methods to assemble these molecules, and each has significant limitations. Here, we report the use of pyridinium benzoxazole (PyBox) salts as heptamethine indocyanine precursors. This method is high yielding, simple to implement, and provides access to previously unknown chromophore functionality. We applied this method to create molecules to address two outstanding objectives in NIR fluorescence imaging. First, we used an iterative approach to develop molecules for protein-targeted tumor imaging. When compared to common NIR fluorophores, the optimized probe increases the tumor specificity of monoclonal antibody (mAb) and nanobody conjugates. Second, we developed cyclizing heptamethine indocyanines with the goal of improving cellular uptake and fluorogenic properties. By modifying both the electrophilic and nucleophilic components, we demonstrate that the solvent sensitivity of the ring-open/ring-closed equilibrium can be modified over a wide range. We then show that a chloroalkane derivative of a compound with tuned cyclization properties undergoes particularly efficient no-wash live cell imaging using organelle-targeted HaloTag self-labeling proteins. Overall, the chemistry reported here broadens the scope of accessible chromophore functionality, and, in turn, enables the discovery of NIR probes with promising properties for advanced imaging applications.

Modified norcyanines enable ratiometric pH imaging beyond 1000 nm.

Activatable fluorophores with emission beyond 1000 nm have the potential to enable high contrast imaging in complex in vivo settings. However, there are few scaffolds that can be applied to this challenge. Here we detail the synthesis and evaluation of benzo[c,d]indole-substituted norcyanines that enable pH responsive fluorescence imaging in the long wavelength (>1150 nm) range. A key component of our molecular design is the installation of a hydrophilic substituted quaternary amine in the central dihydropyridine ring system. A compound with a C4'-phenyl substituent, but not the C4'-protio homologue, exhibits absorbance maxima of 740 nm and 1130 nm in basic and acidic media, respectively, with evidence of J-aggregate-like properties. These two distinct absorbances enabled ratiometric imaging of probe internalization in a tumor model. Overall, these studies provide a new class of activatable long-wavelength responsive fluorophores with promising photophysical properties.

Cyanine Phototruncation Enables Spatiotemporal Cell Labeling.

Photoconvertible tracking strategies assess the dynamic migration of cell populations. Here we develop phototruncation-assisted cell tracking (PACT) and apply it to evaluate the migration of immune cells into tumor-draining lymphatics. This method is enabled by a recently discovered cyanine photoconversion reaction that leads to the two-carbon truncation and consequent blue-shift of these commonly used probes. By examining substituent effects on the heptamethine cyanine chromophore, we find that introduction of a single methoxy group increases the yield of the phototruncation reaction in neutral buffer by almost 8-fold. When converted to a membrane-bound cell-tracking variant, this probe can be applied in a series of in vitro and in vivo experiments. These include quantitative, time-dependent measurements of the migration of immune cells from tumors to tumor-draining lymph nodes. Unlike previously reported cellular photoconversion approaches, this method does not require genetic engineering and uses near-infrared (NIR) wavelengths. Overall, PACT provides a straightforward approach to label cell populations with spatiotemporal control.

Targeted Dual-Modal PET/SPECT-NIR Imaging: From Building Blocks and Construction Strategies to Applications.

Molecular imaging is an emerging non-invasive method to qualitatively and quantitively visualize and characterize biological processes. Among the imaging modalities, PET/SPECT and near-infrared (NIR) imaging provide synergistic properties that result in deep tissue penetration and up to cell-level resolution. Dual-modal PET/SPECT-NIR agents are commonly combined with a targeting ligand (e.g., antibody or small molecule) to engage biomolecules overexpressed in cancer, thereby enabling selective multimodal visualization of primary and metastatic tumors. The use of such agents for (i) preoperative patient selection and surgical planning and (ii) intraoperative FGS could improve surgical workflow and patient outcomes. However, the development of targeted dual-modal agents is a chemical challenge and a topic of ongoing research. In this review, we define key design considerations of targeted dual-modal imaging from a topological perspective, list targeted dual-modal probes disclosed in the last decade, review recent progress in the field of NIR fluorescent probe development, and highlight future directions in this rapidly developing field.

Cyanine Masking: A Strategy to Test Functional Group Effects on Antibody Conjugate Targeting.

Conjugates of small molecules and antibodies are broadly employed diagnostic and therapeutic agents. Appending a small molecule to an antibody often significantly impacts the properties of the resulting conjugate. Here, we detail a systematic study investigating the effect of various functional groups on the properties of antibody-fluorophore conjugates. This was done through the preparation and analysis of a series of masked heptamethine cyanines (CyMasks)-bearing amides with varied functional groups. These were designed to exhibit a broad range of physical properties, and include hydrophobic (-NMe2), pegylated (NH-PEG-8 or NH-PEG-24), cationic (NH-(CH2)2NMe3+), anionic (NH-(CH2)2SO3-), and zwitterionic (N-(CH2)2NMe3+)-(CH2)3SO3-) variants. The CyMask series was appended to monoclonal antibodies (mAbs) and analyzed for the effects on tumor targeting, clearance, and non-specific organ uptake. Among the series, zwitterionic and pegylated dye conjugates had the highest tumor-to-background ratio (TBR) and a low liver-to-background ratio. By contrast, the cationic and zwitterionic probes had high tumor signal and high TBR, although the latter also exhibited an elevated liver-to-background ratio (LBR). Overall, these studies provide a strategy to test the functional group effects and suggest that zwitterionic substituents possess an optimal combination of high tumor signal, TBR, and low LBR. These results suggest an appealing strategy to mask hydrophobic payloads, with the potential to improve the properties of bioconjugates in vivo.

QuatCy-I2 and MHI-I2 in Photodynamic Therapy.

MHI-I2 (1) and QuatCy-I2 (2) were compared in terms of properties important for early-stage photodynamic therapy preclinical candidates. Thus, experiments were performed to monitor dark cytotoxicities, light/dark cytotoxicity ratios, selectivity of localization in tumors over other organs, and clearance from the plasma.

Antibody-dependent cellular phagocytosis of tropomyosin receptor kinase C (TrkC) expressing cancer cells for targeted immunotherapy.

Conventional cancer therapies such as chemotherapy are non-selective and induce immune system anergy, which lead to serious side effects and tumor relapse. It is a challenge to prime the body's immune system in the cancer-bearing subject to produce cancer antigen-targeting antibodies, as most tumor-associated antigens are expressed abundantly in cancer cells and some of normal cells. This study illustrates how hapten-based pre-immunization (for anti-hapten antibodies production) combined with cancer receptor labeling with hapten antigen constructs can elicit antibody-dependent cellular phagocytosis (ADCP). Thus, the hapten antigen 2,4-dinitrophenol (DNP) was covalently combined with a cancer receptor-binding dipeptide (IYIY) to form a dipeptide-hapten construct (IYIY-DNP, MW = 1322.33) that targets the tropomyosin receptor kinase C (TrkC)-expressed on the surface of metastatic cancer cells. IYIY-DNP facilitated selective association of RAW264.7 macrophages to the TrkC expressing 4T1 cancer cells in vitro, forming cell aggregates in the presence of anti-DNP antibodies, suggesting initiation of anti-DNP antibody-dependent cancer cell recognition of macrophages by the IYIY-DNP. In in vivo, IYIY-DNP at 10 mg/kg suppressed growth of 4T1 tumors in DNP-immunized BALB/c mice by 45% (p < 0.05), when comparing the area under the tumor growth curve to that of the saline-treated DNP-immunized mice. Meanwhile, IYIY-DNP at 10 mg/kg had no effect on TrkC-negative 67NR tumor-bearing mice immunized with DNP. Tumor growth suppression activity of IYIY-DNP in DNP-immunized mice was associated with an increase in the anti-DNP IgG (7.3 × 106 ± 1.6 U/mL) and IgM (0.9 × 106 ± 0.07 U/mL) antibodies after five cycles of DNP treatment, demonstrated potential for hapten-based pre-immunization then treatment with IYIY-DNP to elicit ADCP for improved immunotherapy of TrkC expressing cancers.

Targeted Fluorogenic Cyanine Carbamates Enable In Vivo Analysis of Antibody-Drug Conjugate Linker Chemistry.

Antibody-drug conjugates (ADCs) are a rapidly emerging therapeutic platform. The chemical linker between the antibody and the drug payload plays an essential role in the efficacy and tolerability of these agents. New methods that quantitatively assess the cleavage efficiency in complex tissue settings could provide valuable insights into the ADC design process. Here we report the development of a near-infrared (NIR) optical imaging approach that measures the site and extent of linker cleavage in mouse models. This approach is enabled by a superior variant of our recently devised cyanine carbamate (CyBam) platform. We identify a novel tertiary amine-containing norcyanine, the product of CyBam cleavage, that exhibits a dramatically increased cellular signal due to an improved cellular permeability and lysosomal accumulation. The resulting cyanine lysosome-targeting carbamates (CyLBams) are ∼50× brighter in cells, and we find this strategy is essential for high-contrast in vivo targeted imaging. Finally, we compare a panel of several common ADC linkers across two antibodies and tumor models. These studies indicate that cathepsin-cleavable linkers provide dramatically higher tumor activation relative to hindered or nonhindered disulfides, an observation that is only apparent with in vivo imaging. This strategy enables quantitative comparisons of cleavable linker chemistries in complex tissue settings with implications across the drug delivery landscape.

Coumarins to Cyanines: Synthesis of Hemicyanines.

Near-infrared (NIR) emitting fluorophores are powerful tools for optical imaging. However, there are only a handful of broadly employed NIR-emitting scaffolds, and the synthetic methods to prepare these molecules are often problematic. Here, we describe a novel, three-step synthesis of chromene-containing hemicyanine probes exhibiting large Stokes shifts and NIR emissions. We develop a pH-activatable probe for visualizing lysosomal trafficking of mAb conjugates. These studies provide a concise approach to hemicyanines with promising properties.

Fluorescent kinase inhibitors as probes in cancer.

Fluorescent dyes attached to kinase inhibitors (KIs) can be used to probe kinases in vitro, in cells, and in vivo. Ideal characteristics of the dyes vary with their intended applications. Fluorophores used in vitro may inform on kinase active site environments, hence the dyes used should be small and have minimal impact on modes of binding. These probes may have short wavelength emissions since blue fluorophores are perfectly adequate in this context. Thus, for instance, KI fragments that mimic nucleobases may be modified to be fluorescent with minimal perturbation to the kinase inhibitor structure. However, progressively larger dyes, that emit at longer wavelengths, are required for cellular and in vivo work. In cells, it is necessary to have emissions above autofluorescence of biomolecules, and near infrared dyes are needed to enable excitation and observation through tissue in vivo. This review is organized to describe probes intended for applications in vitro, in cells, then in vivo. The readers will observe that the probes featured tend to become larger and responsive to the near infared end of the spectrum as the review progresses. Readers may also be surprised to realize that relatively few dyes have been used for fluorophore-kinase inhibitor conjugates, and the area is open for innovations in the types of fluorophores used.

Norcyanine-Carbamates Are Versatile Near-Infrared Fluorogenic Probes.

Fluorogenic probes in the near-infrared (NIR) region have the potential to provide stimuli-dependent information in living organisms. Here, we describe a new class of fluorogenic probes based on the heptamethine cyanine scaffold, the most broadly used NIR chromophore. These compounds result from modification of heptamethine norcyanines with stimuli-responsive carbamate linkers. The resulting cyanine carbamates (CyBams) exhibit exceptional turn-ON ratios (∼170×) due to dual requirements for NIR emission: carbamate cleavage through 1,6-elimination and chromophore protonation. Illustrating their utility in complex in vivo settings, a γ-glutamate substituted CyBam was applied to imaging γ-glutamyl transpeptidase (GGT) activity in a metastatic model of ovarian cancer. Overall, CyBams have significant potential to extend the reach of fluorogenic strategies to intact tissue and live animal imaging applications.

Hows and Whys of Tumor-Seeking Dyes.

Active targeting uses molecular fragments that bind receptors overexpressed on cell surfaces to deliver cargoes, and this selective delivery to diseased over healthy tissue is valuable in diagnostic imaging and therapy. For instance, targeted near-infrared (near-IR) dyes can mark tissue to be excised in surgery, and radiologists can use active targeting to concentrate agents for positron emission tomography (PET) in tumor tissue to monitor tumor metastases. Selective delivery to diseased tissue is also valuable in some treatments wherein therapeutic indexes (toxic/effective doses) are key determinants of efficacy. However, active targeting will only work for cells expressing the pivotal cell surface receptor that is targeted. That is a problem because tumors, even ones derived from the same organ, are not homogeneous, patient-to-patient variability is common, and heterogeneity can occur even in the same patient, so monotherapy with one actively targeted agent is unlikely to be uniformly effective. A particular category of fluorescent heptamethine cyanine-7 (Cy-7) dyes, here called tumor seeking dyes, offer a way to circumvent this problem because they selectively accumulate in any solid tumor. Furthermore, they persist in tumor tissue for several days, sometimes longer than 72 h. Consequently, tumor seeking dyes are near-IR fluorescent targeting agents that, unlike mAbs (monoclonal antibodies), accumulate in any solid lesion, thus overcoming tumor heterogeneity, and persist there for long periods, circumventing the rapid clearance problems that bedevil low molecular mass drugs. Small molecule imaging agents and drugs attached to tumor-seeking dyes have high therapeutic indices and long residence times in cancer cells and tumor tissue. All this sounds too good to be true. We believe most of this is true, but the controversy is associated with how and why these characteristics arise. Prior to our studies, the prevailing hypothesis, often repeated, was that tumor seeking dyes are uptaken by organic anion transporting polypeptides (OATPs) overexpressed on cancer cells. This Account summarizes evidence indicating tumor seeking Cy-7 dyes have exceptional accumulation and persistence properties because they covalently bind to albumin in vivo. That adduct formation provides a convenient way to form albumin-bound pharmaceuticals labeled with near-IR fluorophores which can be tracked in vivo. This understanding may facilitate more rapid developments of generally applicable actively targeted reagents.

Not so innocent: Impact of fluorophore chemistry on the in vivo properties of bioconjugates.

The combination of targeting ligands and fluorescent dyes is a powerful strategy to observe cell types and tissues of interest. Conjugates of peptides, proteins, and, in particular, monoclonal antibodies (mAbs) exhibit excellent tumor targeting in various contexts. This approach has been translated to a clinical setting to provide real-time molecular insights during the surgical resection of solid tumors. A critical element of this approach is the generation of highly fluorescent bioconjugates that maintain the properties of the parent targeting ligand. A number of studies have found that fluorophores can dramatically impact the pharmacokinetic and tumor-targeting properties of the bioconjugates they are meant to only innocently observe. In this review, we summarize several examples of these effects and highlight strategies that have been used to mitigate them. These include the application of site-specific labeling chemistries, modulating label density, and altering the structure of the fluorescent probe itself. In particular, we point out the significant potential of fluorophores with hydrophilic but net-neutral structures. Overall, this review highlights recent progress in refining the in vivo properties of fluorescent bioconjugates, and we hope, will inform future efforts in this area.

Physical and Psychological Symptoms Associated With Premenstrual Syndrome and Their Impact on the Daily Routine of Women in a Low Socioeconomic Status Locality.

Introduction The constellation of the physical and psychological symptoms that appear several days before menstrual period is regarded as the premenstrual syndrome (PMS). The current study evaluated the symptoms associated with PMS and their impact on the day-to-day activities of women. Methodology An observational cross-sectional study was conducted at a squatter settlement in Karachi, Pakistan, from January 2019 to February 2020. Amenorrheic, pregnant women, and women who were on birth control at the time of data collection were excluded from the study. The demographics, symptoms of PMS experienced by the participants, and the impact of PMS symptoms on the daily lives of women were recorded. Statistical Package for the Social Sciences v.25 (IBM Corp., Armonk, NY) was used for data analysis.  Results The mean age ± standard deviation of 23.93 years ± 9.41 years was recorded. As many as 213 (63%) women reported dysmenorrhea, followed by fatigue in 108 (32%), bloating in 64 (18.9%), and back pain in 45 (13.3%) women. Irritability and anxiety were experienced by 134 (39.6%) and 117 (34.6%) women, respectively. When asked about their attitude and perception towards menstruation, more than four-fifth respondents confessed that they feel impure when they are experiencing their monthly period. About 38 women (11.2%) believed that menstruation is God's way of punishing the womankind. For the question, "Do you feel that your normal routine is significantly disturbed during your period?", 40% responded in affirmation. Conclusion The findings of the current study reflected a generally negative attitude towards menstruation, which significantly affected the routine lives of women in our setting. The study further concluded that dysmenorrhea, fatigue, irritability, and anxiety were the most common symptoms of PMS experienced by women.

Impact of Diabetes-related Self-management on Glycemic Control in Type II Diabetes Mellitus.

INTRODUCTION:  Self-care activities are behaviors adopted in order to enhance one's health. Self-care behaviors and activities are studied in their role to enhance glycemic control, reduce diabetes-related complications, and contribute to enhancing overall quality of life in people with diabetes. The aim of this observational study was to evaluate the impact of diabetes self-care activities and behaviors on glycemic control in people with diabetes. METHODS:  This observational, cross-sectional study was conducted at the outpatient department of a secondary care hospital in Karachi, Pakistan from 1st September 2019 till 30th November 2019. Patients with known type II diabetes of age ≥45 years visiting the hospital for routine follow-up visit were included. Diabetes Self-Management Questionnaire (DSMQ) in Urdu version was used to assess their status of self-management. For data entry and statistical analysis SPSS for Windows version 21.0 was used. RESULTS:  There were 174 (54.9%) males and 152 (47.9%) were of age 45-60 years. Glycemic control was good (HbA1c <7%) in 125 (39.4%) and poor (HbA1c ≥7%) in 192 (60.6%) patients. Patients with good glycemic control scored significantly better on DSMQ overall (5.53 ± 0.35 vs. 4.32 ± 0.61; p<0.0001), and on three sub-scales - dietary control (4.24 ± 1.04 vs. 3.63 ± 0.98; p<0.0001), physical activity (4.16 ± 0.56 vs. 3.47 ± 1.17; p<0.0001), and healthcare use (4.22 ± 0.78 vs. 3.98 ± 0.65; p=0.003).  Conclusions: The self-care activities that impact glycemic control in patients with diabetes include dietary control, physical activity, and healthcare use.

Role of Albumin in Accumulation and Persistence of Tumor-Seeking Cyanine Dyes.

Some heptamethine cyanine dyes accumulate in solid tumors in vivo and persist there for several days. The reasons why they accumulate and persist in tumors were incompletely defined, but explanations based on uptake into cancer cells via organic anion transporting polypeptides (OATPs) have been widely discussed. All cyanine-based "tumor-seeking dyes" have a chloride centrally placed on the heptamethine bridge (a "meso-chloride"). We were intrigued and perplexed by the correlation between this particular functional group and tumor uptake, so the following study was designed. It features four dyes (1-Cl, 1-Ph, 5-Cl, and 5-Ph) with complementary properties. Dye 1-Cl is otherwise known as MHI-148, and 1-Ph is a close analog wherein the meso-chloride has been replaced by a phenyl group. Data presented here shows that both 1-Cl and 1-Ph form noncovalent adducts with albumin, but only 1-Cl can form a covalent one. Both dyes 5-Cl and 5-Ph have a methylene (CH2) unit replaced by a dimethylammonium functionality (N+Me2). Data presented here shows that both these dyes 5 do not form tight noncovalent adducts with albumin, and only 5-Cl can form a covalent one (though much more slowly than 1-Cl). In tissue culture experiments, uptake of dyes 1 is more impacted by the albumin in the media than by the pan-OATP uptake inhibitor (BSP) that has been used to connect uptake of tumor-seeking dyes in vivo with the OATPs. Uptake of 1-Cl in media containing fluorescein-labeled albumin gave a high degree of colocalization of intracellular fluorescence. No evidence was found for the involvement of OATPs in uptake of the dyes into cells in media containing albumin. In an in vivo tumor model, only the two dyes that can form albumin adducts (1-Cl and 5-Cl) gave intratumor fluorescence that persisted long enough to be clearly discerned over the background (∼4 h); this fluorescence was still observed at 48 h. Tumors could be imaged with a higher contrast if 5-Cl is used instead of 1-Cl, because 5-Cl is cleared more rapidly from healthy tissues. Overall, the evidence is consistent with in vitro and in vivo results and indicates that the two dyes in the test series that accumulate in tumors and persist there (1-Cl and 5-Cl, true tumor-seeking dyes) do so as covalent albumin adducts trapped in tumor tissue via uptake by some cancer cells and via the enhanced permeability and retention (EPR) effect.

Depression Among Patients with Chronic Cluster Headaches.

INTRODUCTION: Chronic headaches account for a significant proportion of people leading a poor quality of life. Chronic cluster headaches can be defined as episodes of headache usually around the eye in the pattern of a cluster lasting 15-180 minutes each followed by multiple similar episodes occurring at a frequency of 1-8 times per day. METHOD: This cross-sectional study was conducted in Jinnah Postgraduate Medical Center, Karachi. One hundred patients who were diagnosed cases of chronic cluster headaches were asked to fill the Beck Hopelessness Scale (BHS), Headache Impact Test (HIT), and Hospital Anxiety and Depression Scale (HADS). RESULTS: Of our study subjects, 57 were males and 43 were females. The mean HIT-6 score among these patients was found to be 60.5±7.67 (p-value = 0.04). The mean BHS score among these patients was found to be 13±6.87. The mean HADS reporting anxiety (HADS-A) was found to be 12.54 ± 5.65; whereas, the mean HADS reporting depression (HADS-D) was found to be 7.65 ± 4.65. CONCLUSION: Patients with chronic cluster headaches have higher scores than the general population. There is an association between headache syndromes and depression which require further investigation.

Sensorineural Hearing Loss and Its Relationship with Duration of Chelation Among Major ß-Thalassemia Patients.

Introduction Thalassemia is a common genetic disorder worldwide, also occurring frequently in Karachi, Pakistan. Beta (ß)-thalassemia major patients need repeated transfusions which cause iron overload. Patients are treated with chelating agents to reduce the high serum ferritin level and to decrease morbidity and mortality due to increased iron levels. This combined therapy also leads to some complications. One of them is the sensorineural hearing loss (SNHL). To date, no data is available in Pakistan regarding SNHL among major ß-thalassemia patients on chelating therapy.  Methods A cross-sectional study was performed in collaboration with the Thalassemia Center and Dr. Ruth Pfau at the Department of Ear, Nose, and Throat, Civil Hospital, Karachi, Pakistan. The variable to detect hearing was pure tone air and bone conduction thresholds at the frequencies of 250 - 4,000 Hz. Clinical data, such as chelating agent dose, duration, and hearing status, were recorded. Demographic characteristics, like age, gender, height, and weight, were noted. The hemoglobin and serum ferritin levels of the subjects were also included. Results Forty-five percent of cases of thalassemia were suffering from SNHL. In the right ear, the Pearson correlation of chelating agent dose (mg) with SNHL was mildly positive and statistically significant (r = 0.261, p < 0.001), (r = 0.337, p < 0.001), (r = 0.198, p = 0.005), and (r = 0.207, p = 0.003) at the frequencies of 250, 500, 1,000, and 2,000 Hz, respectively, and the Pearson correlation of chelating agent used (in months) with SNHL was mildly positive and statistically significant (r = 0.232, p = 0.001), and (r = 0.301, p < 0.001) at frequencies 250 to 500 Hz, respectively. In the left ear, the Pearson correlation of chelating agent dose (mg) with SNHL was mildly positive and statistically significant, (r = 0.191, p = 0.007), (r = 0.202, p = 0.004), (r = 0.297, p < 0.001), (r = 0.183, p = 0.010) and (r = 0.221, p = 0.002) at frequencies 250, 500, 1,000, 2,000, and 4,000 Hz, respectively, and Pearson correlation of chelating agent used (months) with SNHL was mildly positive and statistically significant only at the frequency of 2,000 Hz (r = 140, p = 0.049).  Conclusion Chelation therapy and regular blood transfusions, apart from prolonging the life of thalassemic patients, also leads to some complications. With this survey, it was concluded that almost half of the patients had normal hearing, while the other half had sensorineural hearing loss after the use of deferasirox. It is inferred that the incidence of SNHL is not only dose-related but the duration of use of a chelating agent is also a contributing factor.

Cyanine-Gemcitabine Conjugates as Targeted Theranostic Agents for Glioblastoma Tumor Cells.

A small subset of heptamethine dyes (cyanine-7 or Cy7) share an intriguing characteristic: preferential tumor accumulation and retention. These dyes absorb in the near-infrared (NIR) region (above 750 nm) and perform active targeting to deliver therapeutic and toxic cargoes to various tumor models in vivo. In this work, four heptamethines 1 were synthesized, which have a gemcitabine fragment attached to the meso-position of the Cy7 core. Theranostic agent 1a was discovered that localized in glioblastoma tumor cells, has absorption maxima in NIR region, and showed similar therapeutic effect to gemcitabine but at one-third the molar dose.