CTC together with Shh and Nrf2 are prospective diagnostic markers for HNSCC

BACKGROUND

The lack of appropriate prognostic biomarkers remains a significant obstacle in the early detection of Head and Neck Squamous Cell Carcinoma (HNSCC), a cancer type with a high mortality rate. Despite considerable advancements in treatment, the success in diagnosing HNSCC at an early stage still needs to be improved. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Sonic Hedgehog (Shh) are overexpressed in various cancers, including HNSCC, and have recently been proposed as possible therapeutic targets for HNSCC. Circulating Tumor Cell (CTC) is a novel concept used for the early detection of cancers, and studies have suggested that a higher CTC count is associated with the aggressiveness of HNSCC and poor survival rates. Therefore, we aimed to establish molecular markers for the early diagnosis of HNSCC considering Shh/Nrf2 overexpression in the background. In addition, the relation between Shh/Nrf2 and CTCs is still unexplored in HNSCC patients.

METHODS

In the present study, we selected a cohort of 151 HNSCC patients and categorized them as CTC positive or negative based on the presence or absence of CTCs in their peripheral blood. Data on demographic and clinicopathological features with the survival of the patients were analyzed to select the patient cohort to study Shh/Nrf2 expression. Shh and Nrf2 expression was measured by qRT-PCR.

RESULTS

Considering significant demographic [smoking, betel leaf (p-value < 0.0001)] and clinicopathological risk factors [RBC count (p < 0.05), Platelet count (p < 0.05), Neutrophil count (p < 0.005), MCV (p < 0.0001), NLR (p < 0.05), MLR (p < 0.05)], patients who tested positive for CTC also exhibited significant overexpression of Shh/Nrf2 in both blood and tissue compared to CTC-negative patients. A strong association exists between CTCs and tumor grade. Following chemotherapy (a combination of Cisplatin, 5FU, and Paclitaxel), the frequency of CTCs was significantly decreased in patients with HNSCC who had tested positive for CTCs. The Kaplan-Meier plot illustrated that a higher number of CTCs is associated with poorer overall survival (OS) in patients with HNSCC.

CONCLUSIONS

Detecting CTCs, and higher expression of Shh and Nrf2 in HNSCC patients' blood, can be a promising tool for diagnosing and prognosticating HNSCC.

Magnetically-activated, nanostructured cellulose for efficient capture of circulating tumor cells from the blood sample of head and neck cancer patients

In this report, the relative efficiency of cellulose nanocrystals (CNCs) and nanofibers (CNFs) to capture circulating tumor cells (CTCs) from the blood sample of head and neck cancer (HNC) patients was evaluated. Detection and enumeration of CTCs are critical for monitoring cancer progression. Both types of nanostructured cellulose were chemically modified with Epithelial Cell Adhesion Molecule (EpCAM) antibody and iron oxide nanoparticles. The EpCAM antibody facilitated the engagement of CTCs, promoting entrapment within the cellulose cage structure. Iron oxide nanoparticles, on the other hand, rendered the cages activatable via the use of a magnet for the capture and separation of entrapped CTCs. The efficiency of the network structures is shown in head and neck cancer (HNC) patients' blood samples. It was observed that the degree of chemical functionalization of hydroxyl groups located within the CNCs or CNFs with anti-EpCAM determined the efficiency of the system's interaction with CTCs. Further, our result indicated that inflexible scaffolds of nanocrystals interacted more efficiently with CTCs than that of the fibrous CNF scaffolds. Network structures derived from CNCs demonstrated comparable CTC capturing efficiency to commercial standard, OncoDiscover®. The output of the work will provide the chemical design principles of cellulosic materials intended for constructing affordable platforms for monitoring cancer progression in 'real time'.

Role of circulating tumour cells (CTCs) in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC)

Background

Liquid biopsy is emerging as a non-invasive tool, providing a personalized snapshot of a primary and metastatic tumour. It aids in detecting early metastasis, recurrence or resistance to the disease. We aimed to assess the role of circulating tumour cells (CTCs) as a predictive biomarker in recurrent/metastatic head and neck cancer (head and neck squamous cell carcinoma (HNSCC)).

Methodology

Thirty-five patients receiving palliative chemotherapy underwent blood sampling [2 mL in Ethylenediaminetetraacetic acid (EDTA) vial] at baseline and at 3 months intervals. The CTCs were isolated and evaluated using anti-epithelial cell adhesion molecule antibody-based enrichment using the OncoDiscover platform.

Results

CTCs isolated from 80% of patients (n = 28) showed the sensitivity of cell detection at the baseline and 3 months intervals. The median CTC count was 1/1.5 mL of blood and the concordance with clinic-radiological outcomes was 51.4%. The median CTC count (1 (range:0-4) to 0 (range:0-1)) declined at 3 months in responders, while the non-responders had an increase in levels (0 (range :0-2) to 1 (range :0-3)). Although CTCs positively correlated with progression-free survival (PFS) and overall survival (OS), the association of CTCs did not show a significant difference with these parameters (PFS: 6 months versus 4 months; hazard ratio: 0.68; 95% confidence interval (CI): 0.29-1.58, p = 0.323; OS: 10 months versus 8 months; hazard ratio: 0.54; 95% (CI):0.18-1.57 p = 0.216) between CTC positive and CTC negative patients at 3 months.

Conclusion

This study highlights the utility of CTC as a disease progression-monitoring tool in recurrent HNSCC patients. Our findings suggest the potential clinical utility of CTC and the need for exploration in upfront settings of the disease as well (NCT: CTRL/2020/02/023378).

Chemical tunability of advanced materials used in the fabrication of micro/nanobots

Micro and nanobots (MNBs) are unprecedented in their ability to be chemically tuned for autonomous tasks with enhanced targeting and functionality while maintaining their mobility. A myriad of chemical modifications involving a large variety of advanced materials have been demonstrated to be effective in the design of MNBs. Furthermore, they can be controlled for their autonomous motion, and their ability to carry chemical or biological payloads. In addition, MNBs can be modified to achieve targetability with specificity for biological implications. MNBs by virtue of their chemical compositions may be limited by their biocompatibility, tissue accumulation, poor biodegradability and toxicity. This review presents a note on artificial intelligence materials (AIMs), their importance, and the dimensional scales at which intrinsic autonomy can be achieved for diverse utility. We briefly discuss the evolution of such systems with a focus on their advancements in nanomedicine. We highlight MNBs covering their contemporary traits and the emergence of a few start-ups in specific areas. Furthermore, we showcase various examples, demonstrating that chemical tunability is an attractive primary approach for designing MNBs with immense capabilities both in biology and chemistry. Finally, we cover biosafety and ethical considerations in designing MNBs in the era of artificial intelligence for varied applications.

Abstract 6684: Detection of PD-L1, HER2 and EGFR on circulating tumor cells in carcinoma patients

Background: Small molecular inhibitors and immunotherapy has emerged as a novel alternative treatment regime for a variety of epithelial cancers. Large number of clinical trials are in progress to gauge efficacy of tyrosine kinase inhibitors or immune checkpoint inhibitors against actionable targets such as receptor tyrosine kinases and program death ligand 1 (PD-L1). Although highly effective, the outcome of PD-L1 based ICI or TKI against RTKs is vitally contingent on the presence of PD-L1 or RTK expression on circulating tumor cells. We report validation of CTCs with PD-L1, HER2 and EGFR expression in different epithelial cancers.

Methods: We retrospectively evaluated 134 carcinoma patients blood for presence of CTCs expressing PD-L1, HER2 or EGFR markers respect. 45 % patients had lung cancer, while 25 % and 20 % were presented with breast and GI and CRC malignancies. Remaining were gallbladder, ovarian, prostate, and head and neck cancers. CTCs were isolated from DCGI approved OncoDiscover platform with immunomagnetic targeting of EpCAM. CTCs were confirmed with expression of CK18, absence of CD45 and presence of DAPI nucleus. Presence/absence of biomarkers was determined using fluorescence imaging. Expression of PD-L1, HER2 or EGFR was detected by fluorescence microscopy using fluorescently labelled anti PD-L1, HER2 or EGFR antibodies respect. Based on fluorescence intensity CTCs were binned as PD-L1, HER2 or EGFR negative for no detectable fluorescence signal or weakly or strongly positive based on low or high fluorescence signal.

Results: Among the evaluated cohort, 51% of CTCs showed presence of PD-L1 expression. While 63% showed HER2 positive CTCs (breast cancer). 20% from the PD-L1 positive population showed stronger PD-L1 expression. 78% of CTCs from lung cancer patients showed presence of detectable PD-L1 signal, while 66% breast, GI and CRC patients showed CTCs with PD-L1 expression. CTCs from HNC and gall bladder cancer patients showed low PD-L1 expression (25% and 50% respect.). Among CTCs originating from different cancer types, breast cancer CTCs showed higher mean expression of PD-L1 compared to CTCs from CRC patients. A clear subset of CTCs for PD-L1 and Her2 expression was observed in lung and breast cancer patients respect, suggesting the heterogeneity in expression or presence of different subclones within the same tumor type. CTCs evaluated for EGFR expression, 50% showed presence of detectable EGFR compared to the cut-off signal.

Conclusions: CTC can be used as a real-time surrogate for molecular profiling of PD-L1, HER2 and EGFR expression. These CTC cell surface markers offer alternative for immunotherapy or targeted therapies decisions in a adenocarcinomas.

Citation Format: Jayant Khandare, Atul Bharde, Sreeja Jayant, Gourishankar Aland, Meghana Garbhe, Sayali Gosavi, Apoorva Janorkar, Purva Tikekar, Mrunmayi Patil, Vikas Jadhav, Ganesh Khutale, Amrut Ashturkar, Aravindan Vasudevan, Kumar Prabhash, Nirmal Raut, Pankaj Chaturvedi. Detection of PD-L1, HER2 and EGFR on circulating tumor cells in carcinoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6684.

Abstract 3379: Comprehensive circulating tumor DNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signature of disease progression

Comprehensive CtDNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signatures of disease progressionBackground: We performed comprehensive ctDNA analysis on early-stage HNC patients in a pilot study to determine the mutational landscape in HNC patients with a known tobacco history. Methods: We analysed ctDNA of 18 early-stage HNC patients for genomic landscapes using the illumina NextSeq 2000 NGS. A custom-designed OncoIndex gene panel was used for the hybrid capture target-enrichment of critical cancer genes. Panel was designed to detect cancer targeting exonic sequence of 600 genes reporting SNVs and indels along fusions and copy number amplification. The gene panel detected genome-wide signatures including bTMB, MSI (microsatellite instability), HRD (homologous recombination deficiency) prediction and calculate cfDNA tumor fraction. Results: 80 % patients showed presence of at least one CTC in peripheral blood, possibly indicating the progressive disease at the time of presentation. Comprehensive genomic profile obtained from plasma cfDNA of early-stage HNC cancer patients predominantly had low bTMB and MSI Scores (99 % patients). However, HRD and LOH matrix was high for 60 % patients indicating highly dysregulated DNA repair activities. Concurring to these observations, 98 % patients had mutations in key tumor suppressor and DNA damage response (DDR) genes possibly resulting in their loss of function. Besides DNA damage pathway, 60% patients harboured alterations in RTK genes including FGFR, EGFR and PDEGFR family and 32% patients showed activating mutations in Erk1 and its upstream regulators. MSH2 was the most prominently mutated gene (37%) followed by FGFR (32%). Surprisingly, unlike HPV positive advanced HNC cases, TP53 mutations were not detected in any patient, though alterations in TS genes were most prevalent in the study population. 51% alterations resulted into truncated proteins possibly impairing their functions, while 42% alterations were point mutations, 6 % were frameshift and 1 % indels. Presence of mutations in BRAF, PDGFR, FGFR and KIT genes suggested for the potential therapy resistance. Tumor fraction representing ctDNA showed elevated range from 20 % to 45 % with a corresponding ploidy between 2 to 4. Conclusions: Comprehensive ctDNA profile showed major gene alterations in TS and DDR response pathway genes besides mutations in proliferative signaling members. TP53 mutation was not detected, although critical tumor suppressor and DDR genes were predominantly mutated, suggesting for a unique mutation pattern associated with early-stage HNC due to tobacco etiology. Our results suggest that comprehensive ctDNA analysis along CTC profiling can predict the disease progression beforehand and may offer new treatment options to early-stage HNC patients.

Citation Format: Gowhar Shafi, Atul Bharde, Fauzul Moubeen, Kanchan Hariramani, Alain D’Souza, Trupti Kad, Bhagwat Jadhav, Sangita Prajapati, Aditi Rani, Madhura Basavalingegowda, Mohan Uttarwar, Gourishankar Aland, Sreeja Jayant, Aravindan Vasudevan, Pankaj Chaturvedi, Jayant Khandare. Comprehensive circulating tumor DNA and CTC profiling of treatment naïve early-stage head and neck cancer patients reveals early signature of disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3379.

Abstract PR007: Comprehensive ctDNA profiling reveals potential metastatic genomic signatures in treatment-naive early-stage breast cancer patients

Background: Genomic profiling has revolutionized precision oncology impacting the diagnosis, prognosis, and therapy decisions. Considering high spatiotemporal diversity and heterogenicity of breast tumor-cell genomes, small-gene panels often fail to capture rare but important genomic alterations. Conversely, comprehensive ctDNA sequencing approaches enable the identification of under characterized ‘long tailed driver’ genomic alterations and capture Intra and inter metastatic heterogeneity. Here, we demonstrate the clinical utility of comprehensive genome profiling with higher sensitivity to predict the possibility of metastasis in early-stage breast cancer patients. Methods: We retrospectively analyzed ctDNA and genomic DNA (gDNA) from FFPE samples as well as circulating tumor cells (CTC) in 10 treatment-naive hormone positive and HER2 negative, primary-stage breast cancer patients [GS1] using the OncoIndx comprehensive 600 gene panel. The panel captures all important cancer-relevant genomic alterations including Tumor Mutation Burden (TMB), Micro Satellite Instability (MSI), homologous recombination deficiency (HRD) prediction, and cfDNA tumor fraction (TF). CTCs were enumerated from 1.5 ml of blood using the OncoDiscover platform approved by the Drug Controller General of India having anti-EpCAM antibody-mediated immunomagnetic nanoparticles. CTCs were confirmed for cytokeratin 18+ and DAPI + markers and the absence of CD45. Results: Comprehensive genomic profile obtained from ctDNA and gDNA from FFPE of early-stage breast cancer patients predominantly exhibited the presence of alterations in PIK3CA and ESR1 signaling pathways. PIK3CA mutations were present in 77% and 44% of baseline ctDNA and gDNA samples, while ESR1 mutations were present in 44% and 22% of baseline ctDNA and gDNA, respectively. In addition, we observed about 70% additional driver mutations in ctDNA samples suggesting shedding of ctDNA together with CTC (80% positive), a likely positive biomarker of metastasis. About 50% of the patients showed higher TMB and HRD. Notably, TF representing ctDNA varied between 13% to 27% in blood samples with a corresponding ploidy range of 2.9 to 4.7. Surprisingly, ~50% of the patient population matched the mutation profile of clinically confirmed metastatic patients. All the patients harboring potential metastatic driver alterations showed the presence of CTCs in peripheral blood. Conclusions: Comprehensive ctDNA genomic profiling showed potential metastasis driving alterations suggesting the role of ctDNA-based liquid biopsy to predict metastasis in early breast cancer patients. We observed enhanced TF at the time of diagnosis, possibly due to the presence of distant metastasis, high disease burden, and aggressive tumor biology. Our results suggest that ctDNA dynamics at the time of disease presentation can predict early metastasis, and may demonstrate the divergent response of tumor heterogeneity to treatment in early-stage breast cancer.

Citation Format: Gowhar Shafi, Manoj Dongare, Atul Bharde, Moubeen Fauzul, Kanchan Hariramani, Alain D’Souza, Bhagwat Jadhav, Trupti Kad, Sangeeta Prajapati, Vikas Jadhav, ManojKumar Kumaran, Sumit Haldar, Vatsal Mehra, Sujit Joshi, Gourishankar Aland, Richa Dave, Sreeja Jayant, Aravindan Vasudevan, Mohan Uttarwar, Jayant Khandare. Comprehensive ctDNA profiling reveals potential metastatic genomic signatures in treatment-naive early-stage breast cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR007.

Use of Vasopressin as Rescue Therapy in Refractory Hypoxia and Refractory Systemic Hypotension in Term Neonates with Severe Persistent Pulmonary Hypertension-A Prospective Observational Study

OBJECTIVE

 Persistent pulmonary hypertension of the newborn (PPHN) is a serious cardiorespiratory problem. PPHN is frequently associated with refractory hypoxia and hypotension, and optimal management has the potential to improve important clinical outcomes including mortality. The primary objective is to evaluate the efficacy and safety of rescue vasopressin (VP) therapy in the management of severe (refractory) hypoxia and refractory systemic hypotension in term neonates with severe PPHN.

STUDY DESIGN

 Neonates with refractory hypoxia and refractory hypotension due to severe PPHN needing VP were prospectively enrolled in the study. Refractory hypoxia was defined as oxygenation index (OI) ≥ 25 for at least 4 hours after the commencement of high-frequency oscillatory ventilation and nitric oxide at 20 ppm. Refractory hypotension was defined as mean blood pressure lesser than mean gestational age lasting for more than 15 minutes in spite of dopamine infusion at 10 µg/kg/min, adrenaline infusion at 0.3 µg/kg/min, and noradrenaline infusion at 0.1 µg/kg/min.

RESULTS

 Thirty-two neonates with PPHN were recruited. The baseline OI (mean ± standard deviation [SD]) before starting VP was 33.43 ± 16.54 which started decreasing significantly between 1 and 6 hours after the commencement of VP (p < 0.05). The mean blood pressure also increased concomitantly with a significant effect seen by 1 hour (p < 0.05). The vasoactive infusion score before the commencement of VP was mean 46.07 (SD = 25.72) and started decreasing after 12 to 24 hours of commencement of VP (p < 0.05). Lactate levels (mean ± SD) before starting VP were 7.8 ± 8.6 mmol/L and started decreasing between 6 and 12 hours (p < 0.05). Two neonates died due to refractory hypoxia and refractory hypotension (overall mortality 6.2%) CONCLUSION:  Rescue VP therapy is a useful adjunct in the management of neonates with severe PPHN with refractory hypoxia and/or refractory hypotension. Improvement in oxygenation and hemodynamics with the use of VP results in reduced mortality.

KEY POINTS

· Rescue vasopressin is a useful adjunct in the management of neonates with severe PPHN.. · Vasopressin helps reduce OI.. · Vasopressin reduces the vasoactive inotrope score..

Circulating tumor cells as a predictor for poor prognostic factors and overall survival in treatment naïve oral squamous cell carcinoma patients

OBJECTIVE

The aim of this study was to investigate the presence of circulating tumor cells (CTCs) and their correlation with prognostic factors and clinical outcomes in treatment-naive patients with oral squamous cell carcinoma.

STUDY DESIGN

CTCs were isolated using OncoDiscover technique from presurgically obtained peripheral blood of 152 patients with treatment naïve oral squamous cell carcinoma. Sensitivity analysis was performed by including 40 healthy controls. CTCs cutoff values for clinicopathologic factors were obtained from receiver operating characteristic curves. Multivariate models determined the significance of CTC as independent variables. Kaplan-Meier analysis differentiated in overall survival between CTC values corresponding to the stage.

RESULTS

Sensitivity, specificity, and accuracy of CTC detection were 94.32%, 98%, and 95.17%, respectively. Platform differentiated true positives at >3.5 CTCs (P < .00001). CTCs above 20.5 were suggestive of nodal metastasis (P < .0001) with a linear trend for detecting occult metastasis (P = .061). Early and advanced stages could be differentiated by >13.5 CTCs (P < .0001). Elevated CTCs were significantly associated with extranodal extension (>21.45 CTCs, P = .025), perineural invasion (>19.35 CTCs, P = .049), and depth of invasion (>12.5 CTCs, P = .0038). Median survival was reduced by 19 months when CTCs were >13.

CONCLUSIONS

Preoperative CTC levels demonstrated a strong correlation with adverse clinicopathology factors and suggested its role as a sensitive prognostic marker to predict survival outcome and disease progress.

Bioinspired Materials for Wearable Devices and Point-of-Care Testing of Cancer

Wearable, point-of-care diagnostics, and biosensors are on the verge of bringing transformative changes in detection, management, and treatment of cancer. Bioinspired materials with new forms and functions have frequently been used, in both translational and commercial spaces, to fabricate such diagnostic platforms. Engineered from organic or inorganic molecules, bioinspired systems are naturally equipped with biorecognition and stimuli-sensitive properties. Mechanisms of action of bioinspired materials are deeply connected with thermodynamically or kinetically controlled self-assembly at the molecular and supramolecular levels. Thus, integration of bioinspired materials into wearable devices, either as triggers or sensors, brings about unique device properties usable for detection, capture, or rapid readout for an analyte of interest. In this review, we present the basic principles and mechanisms of action of diagnostic devices engineered from bioinspired materials, describe current advances, and discuss future trends of the field, particularly in the context of cancer.

Machine learning (ML)–enabled, circulating tumor cell–based classification of patients for non-prerequisite adjuvant therapy

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Background: Oncology implicates highest precision using next generation diagnostics and progressive therapies assisted by predictive tools. If validated clinically, machine learning (ML) can provide better insights in precision oncology. Furthermore, it longitudinally may stratify the progression of cancer disease burden in a real time. We have developed, Circulating Tumor Cells (CTCs) driven ML model as a predictor for the treatment decision strategy for both surgery and adjuvant therapy in head and neck squamous cell carcinoma (HNSCC) patients. Methods: In this study, a total of 380 HNSCC patients who underwent either surgery alone or surgery plus adjuvant therapy were accounted for. CTCs in patients were stratified based on clinicopathological parameters and using OncoDiscover platform having anti EpCAM antibody system regulated by the Drug Controller of India. Following this, we explored the predictive performance of the ML model on the usefulness of adjuvant therapy in HNSCC patients after the surgery. The available data was randomly divided into two subsets. First, 75%, of the original data was applied for Training the ML, and rest 25% of the data was used as a Test set. Survival curves were generated by Kaplan–Meier method and calculated through the Log rank test. Results: XGBoost machine learning classifier was superior to Random Forest and SVM-based analyses in predicting the usefulness of adjuvant therapy post-surgery using CTC alone or in combination with other clinical parameters in HNSCC patients. Machine learning algorithms were compared for predicting the accuracy of patients stratification. The results for each model were: XGBoost model (Accuracy = 0.84, ROC value = 0.73, Kappa = 0.43); Random Forest model (Accuracy = 0.81 ROC value = 0.70, Kappa = 0.41); SVM model (Accuracy = 0.76, ROC value = 0. 69, Kappa = 0.40). The ROC value of the XGBoost model was highest (0.73) while the ROC value for the SVM model was lower (0.69). We observed that when CTCs were combined with clinicopathological parameters, the accuracy, kappa values and AUC-ROC drastically improved in predicting the usefulness of adjuvant therapy post-surgery. A similar trend was observed when CTCs were combined with clinicopathological parameters in predicting the line of chemotherapy, post-surgery. Conclusions: ML-enabled, CTCs driven predictions can be highly accurate and ascertain the patient treatments. CTCs can be a positive predictor for selecting patient’s treatment regimen in both surgery as well in type of treatment (e.g. surgery alone or surgery + adjuvant therapy). It can also implicate to classify the patients and determine who necessitates an additional adjuvant therapy. Further investigations in this direction are necessary to predict the treatment options based on ML that may improve the overall survival of cancer patients.

Circulating tumor cells as a biomarker for monitoring: Disease progression, treatment response, and minimal residual disease

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Background: To analyze the role of Circulating tumor cells (CTC) as a confirmatory personalized biomarker for monitoring the disease progression, disease burden, and minimal residual disease in epithelial origin cancers. Methods: In this retrospective study, 127 patients with colorectal, breast, and ovarian cancer at stage III and IV were analyzed. The patients were at various stages of intensive chemo and radiotherapy while the CTCs were isolated and enumerated from 1.5 ml of blood. The decision to continue chemotherapy or change to oral metronomic therapy was based on the presence of circulating tumor cells in Stage III. While in stage IV, serial measurement of CTC guided therapy. CTCs were isolated using OncoDiscover platform possessing EpCAM antibody based immunomagnetic targeting of magnetic nanoparticles after RBC lysis. CTCs were imaged and identified as CK18+ and CD45- cells showing a well-defined nucleus using a motorized fluorescence microscope operational with a monochrome camera. CTCs were enumerated using automated image analysis software and counts were expressed as number per 1.5 ml of blood. Results: In this retrospective study we analyzed blood sample from 127 patients with the advanced stage epithelial cancers (breast- 50 %, ovarian -27 %, colorectal- 23 %) for the presence of CTCs. Amongst those, 52 % showed the presence of CTCs (breast- 52 %, ovarian -46 %, colorectal- 58 %). The CTC count ranged between 1-5 / 1.5 ml of blood with mean and median value of 2 and 1. Among the CTC positive population, majority had CTC count of 1 (44.4 %), while more than 2 CTCs were observed in 11 % of population. CTC clusters were detected in 13 % of population which predominantly were stage IV patients. 67 % among the follow up patients showed decrease in CTC count from the baseline due to the prescribed treatment, while 22 % patients showed increase in CTC count from the baseline. 11 % patients did not show change in CTC count from the baseline. When CTCs count was investigated as an independent variable to monitor the therapeutic response, it correlated well with the positive or negative outcome. In few representative cases, the reduction of CTC number from the basal value was indicative of an effective treatment. Exceptionally, in a representative colorectal cancer case, PET showed no primary as well secondary tumor burden, but the presence of CTCs in blood led further investigating an abdominal MRI that indicated multiple liver lesions suggesting micro-metastasis. Subsequent to SIRT treatment, the patient showed complete tumor regression and absence of CTCs in peripheral blood. Conclusions: Our data suggest that CTC can serve as a dynamic intermittent biomarker for monitoring the disease progression in advanced stages and assess the therapeutic response, thus emphasizing the role of CTCs in personalized cancer management.

Extracorporeal microchannel device to capture and eliminate circulating tumor cells from cancer patient’s blood

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Background: Metastatic progression accounts for nearly 90% of cancer-related deaths and has been directly correlated with the presence of circulating tumor cells (CTCs) in numerous carcinomas including breast, lung, ovarian, colorectal, and head and neck cancers. The removal of CTCs from cancer patient’s blood is directly implicated with reduction of extravasation and disease invasiveness to secondary organs. Methods: We designed and printed 3 Dimensional (3D) microchannel devices using biocompatible polymer and packed it with anti-EpCAM (EpCAM) mediated glass-based (G) compositions (G-EpCAM). The computational fluid dynamic (CFD) analysis simulation was explored to optimize the hemodynamic effect of the G-EpCAM device for measuring the pressure and velocity difference for blood along the spiral flow microchannels. Red blood cell (RBC) hemolysis was estimated using G-EpCAM compositions packed in a device to determine optimal biocompatibility. We assessed cancer cell lines (breast cancer MCF7, lung cancer A549) interactions and capture with varying incubation time points, effect of anti-EpCAM concentrations, number of G-EpCAMs, and series of devices. We evaluated G-EpCAM-on-device’s CTC capture capability and biocompatibility using head and neck, colorectal, lung, and ductal breast cancer patient’s blood samples. All G-EpCAM captured CTCs were immuno-stained for cytokeratin 18 (CK18) expression and the optimal fluorescence acquisition intensity was quantified. Results: Extracorporeal G-EpCAM microchannel device was 3D printed and consisted of interlocking top lid and bottom base with inlet and outlet channels. The path length of the spiral device consisted of 20 microchannels with 6.0-feet length. Device accommodated 28 gm of non-hemolytic G-EpCAM compositions. CFD analysis showed 3.8 mm as the ideal channel diameter and 2mm as the superlative G-EpCAM diameter for maximal cells and CTC capture with minimal blood hemolysis (less than 1%) as compared to control. Series 1 and 2 device indicated 90% and 85% cell capture efficiency, respectively using G-EpCAM devices indicating highest interactions and efficiency with cells. Conversely, the first device in series captured the highest cells. In addition, the efficiency improved as the number of G-EpCAM compositions was increased. We accounted device to capture CTCs with specificity having G-EpCAM composition and observed no hemolysis and non-specific interactions with other blood cells like RBCs or leukocytes. Conclusions: Continuous CTC removal from cancer patient’s blood circulation using such device offers promising therapeutic utility in stemming aggressive metastatic invasion and progression for improving the overall survival of epithelial origin cancer patients. Clinical trial information: CTRI U1111/1192-3951.

Correlation of circulating tumor cells as a positive interventional biomarker in cancer patients

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Background: Circulating Tumor Cells (CTC) is a predictive biomarker for accounting disease progression and for minimal residual disease (MRD). Effect of conventional anticancer therapy on CTC count is well documented, however there is paucity of data related to effect of CAM based modality on CTC count in cancer patients. This study provides a preliminary observation about the effect of Ayurveda therapy on CTC count. Methods: The retrospective study involved stratification of 72 cancer patients undergoing cancer and maintenance treatment in a non-conventional, Ayurveda cancer treatment in India. For monitoring of prognosis in cancer patients, CTC count was assesed in patients attending Rasayu Cancer clinic. 17 cancer types, namely, breast cancer, cervix and ovarian cancer, bladder, lung, Head and neck squamous carcinoma, follicular thyroid, diffuse B-cell lymphoma, Hodgkin’s and non-Hodgkin’s, colorectal, Hepatocellular, stomach with abdominal metastasis, metastatic prostate cancer, SCC with lung and skeletal metastasis etc. Total 33 (46%) males and 39 (54.1%) female patients of various types and stages were analyzed for the presence of CTCs retrospectively. CTCs were isolated and renumerated from 1.5 ml of patient’s blood sample using OncoDiscover Liquid Biopsy Technology platform enriched with anti-EpCAM antibody immunomagnetic kit, approved by Drug Controller General of India (DCGI). CTCs were confirmed for cytokeratin+ 18 (CK18), DAPI+ and CD45-. Subsequently CTCs were imaged using Zeiss Axio Observer 7 fluorescence microscope. In 28 patients (50%), CTC was accounted for at both pre and post treatment in duration of 3-6 months. 28 patients were assessed for quality of life measured by FACT-G questionnaire. The outcome was quantified for clinico-pathological parameters; age / gender, cancer types, and CTC distribution. Results: The mean and median CTC distribution was observed to be 15.34 and 12.5, respectively. 8% patients showed the absence of any CTCs (6 subjects (1 male and 5 females). While 32 males (96%) and 34 females (87%) showed presence of CTCs. The correlation coefficient of CTC presence in male and female was significant 0.4799 (p < 0.05). The Ayurveda Rasayana therapy showed significant reduction in post interventional CTC count (-3.94±1.2) (P=0.02). In addition, this group of patients also showed significant improvement in health-related quality of life as measured by the FACT-G questionnaire (P<0.05). Conclusions: CTC is a validated predictive biomarker for accounting minimal residual disease, both in pre and post cancer treatments. The enumeration of CTCs represents an effective prognostic biomarker in assessing the disease progression. Reduction in CTC count was seen to be associated with improvement in health-related quality of life (QoL) which needs to be investigated further to establish correlation.

AI-enabled identification prediction of homologous recombination deficiency (HRD) from histopathology images

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Background: Homologous recombination deficient (HRD) tumors are highly responsive to platinum-based chemotherapy and poly (ADP-ribose) polymerase inhibitor (PARPi) therapy. Pathogenic BRCA-1 and BRCA-2 (BRCA1/2) alterations are key members of the HR DNA repair pathway but genomic instability status, including loss of heterozygosity, telomeric allelic imbalance and large scale state transitions across the genome are also predictive of HRD. HRD testing is currently performed by next generation sequencing which can take 2-4 weeks for results, has a high failure rate, requires significant tissue and is costly. We developed and tested the ability of an AI enabled platform to predict HRD status from the analysis of whole slide imaging of the diagnostic H&E slide. This platform, iPREDICT-HRD is rapid, precise, and cost effective. Methods: The AI engine was trained on 120 H&E slides that were used to identify tumor prior to manual microdisseection for HRD assessment by NGS. Histopathological features were extracted, followed by feature mapping to predict HRD status based on the results of NGS testing. ResNet AI algorithm was trained to segment, annotate and predict HRD status. 10 lac tiles of 256x256 size at 40x magnification were generated per pathological class. 70% of the data set was used for training and 30% for validation of the AI model. Results: Using single blinded clinical samples, iPREDICT-HRD tool detected HRD + ve samples with 99.3% accuracy with 100% sensitivity and 99% specificity in the test set. Patch-level predictions of HRD status demonstrated intra-tumor heterogeneity within the H&E slides. Visual inspection of the heatmap suggested the presence of patches with high predictive ability of HRD status and this outperformed an average HRD score for slides with heterogeneity. Conclusions: AI-enabled prediction of HRD status can be accurately performed on diagnostic H&E slides potentially yielding results quickly and afforadably, even when limited tissue is available for testing.

A feasibility study of EMF(erlotinib+methotrexate+5-fluorouracil) regimen in recurrent head and neck squamous cell carcinoma (HNSCC) and role of circulating tumour cells(CTCs) in assessment of outcomes

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Background: Head and neck cancer is a huge burden in South East Asia with frequent relapse after curative therapy while the rest presenting in advanced unresectable stages. Financial constraints for targeted and immunotherapy make it inaccessible for the bulk of population. Thus, low-cost but efficacious regimen is highly implicated. We assessed if readily available triplet therapy of EMF, is superior in terms of extending life and maintaining quality of life along with evaluation of CTCs as a predictive biomarker in such patients. Methods: This was a single arm, phase II, investigator initiated interventional study, wherein 35 patients were enrolled. Platinum resistant/refractory patients of HNSCC were treated with combination of erlotinib 150mg daily, methotrexate 40 mg/m2 and 5-fluourouracil 500 mg/m2 (d1, d8) q28 days till progression or unacceptable toxicities. The primary endpoint was overall response rate(ORR) at 3 months; additional endpoints were disease control rate(DCR) at 3 months, overall survival (OS), progression free survival (PFS) safety and patient reported quality of life(QOL). The role of CTCs in gauging the responders and non-responders was monitored using anti Epithelial Cell Adhesion Molecule antibody based enrichment - OncoDiscover Drug Controller General of India (DCGI) approved platform. Results: The ORR and DCR at 3 months was 45.7% and 68.5%, respectively. The median PFS was 5 months (95%CI: 3.9-6 months) and median OS was 9 months (95%CI:7.4 -10.5 months). The 3 and 6 months PFS rates was 86 + 6% and 45 + 9%, respectively, while OS rates at 3 and 6 months were 91+ 5% and 68+ 8%, respectively. Rash, mucositis and fatigue were common adverse events occurring in 23 (65%), 14 (40%) and 9 (25.7%) respectively. The grade 3 events seen were rash in 5 (14.2%) and diarrhea in 2 (5.7%). Clinically significant improvement was seen in domains of role functioning, social functioning, fatigue, pain and global health status, swallowing, dryness of mouth and feeling ill. The mean CTC count at baseline was 0.90 + 1.1 /1.5ml of blood. Responders showed decline in levels from 1.19 + 0.25 to 0.33 + 0.48, while non-responders had increasing trend: 0.29 + 0.48 to 1+ 0.10 at 3 months (p = 0.010); with concordance rates with response being 52.9%. Additionally, CTC clearance at 3 months had numerically better PFS ̃ 6 months (95% CI: 4.72-7.72) and OS of 10 months (95% CI: 2.3-5.65) vs 4 months (95% CI: 2.3-5.65), p = 0.258 and 8 months (95% CI: 4.3-11.6), p = 0.203 in those with persistence of CTCs. Conclusions: The triplet regimen of EMF is a feasible, safe therapeutic option with favourable response rates and improved QOL in patients with platinum resistant/refractory HNSCC. CTCs have a promising futuristic role as a predictive biomarker and can be extrapolated in clinical upfront setting too. Clinical trial information: CTRI/2020/02/023378.

Antibody mediated cotton-archetypal substrate for enumeration of circulating tumor cells and chemotherapy outcome in 3D tumors

Circulating tumor cells (CTCs) are distinct cancer biomarkers established in clinical settings for early cancer detection, metastasis progression, and minimal residual disease (MRD) monitoring. Despite numerous advances, the comprehensive molecular characterization of CTCs is extremely challenging owing to their rarity and heterogeneity. Here, we present a novel cotton microfluidic substrate (CMS) as an innovative biomedical matrix that efficiently isolates CTCs while facilitating in vitro CTC expansion to enable a further downstream analysis of these rare cells. CMS enabled static and dynamic isolation of cells from the MCF-7 cancer cell line, as well as from head and neck squamous cell carcinoma (HNSCC) patients' blood and the cell capture efficiencies were further compared with a clinically regulated OncoDiscover® Liquid Biopsy Test. Further, CMS acted as a matrix on which the captured cancer cells were grown in 3D tumor models for studying anti-cancer drug efficacy and multi-drug resistance (MDR) mechanisms. The design of the CMS employed two different surface chemistries, flattened and nanostructured surfaces, each conjugated to anti-EpCAM antibodies to evaluate the CTC capture efficiency and 3D tumor growth dynamics. The nanostructured surface was highly efficient for capturing CTCs and promoted 3D tumor spheroid formation with a 5-fold increase in size from day 03 to day 10 of culture. Moreover, when treated with an anti-cancer drug, cisplatin, an almost 1/2 reduction in tumor size was achieved within 24 hours, followed by a cytostatic threshold and eventual acquisition of drug resistance within 3 days. Conclusively, the CMS matrix exhibits potential for further development of "tissue on chip" and "point-of-care" medical devices in cancer diagnostics, and chemo-therapeutic efficacy evaluations in both drug discovery and development.

Comparison of Invasive Arterial Blood Pressure Monitoring vs. Non-Invasive Blood Pressure Monitoring in Preterm Infants < 37 Weeks in the Neonatal Intensive Care Unit- A Prospective Observational Study

BACKGROUND

Accurate measurement of blood pressure (BP) is extremely important in the management of sick preterm newborns. The primary objective of this study was to compare non-invasive blood pressure measurement (NIBP) with invasive blood pressure measurement (IBP) using peripheral arterial cannulation (PAC) in preterm neonates < 37 weeks in the neonatal intensive care unit.

METHODS

Preterm neonates needing PAC were prospectively enrolled in the study. NIBP measurements were taken in the same limb as that of peripheral arterial line. Initially IBP was recorded followed by NIBP within 1 min using the same monitor. These were called as paired measurements since they are taken within 1 min of each other.

RESULTS

Seventy-three preterm infants with 1703 paired measurements were included in the final analysis (median gestational age 32 weeks, IQR 30-34 weeks, median birth weight 1540 g, IQR 1160-2100 g). In preterm infants not receiving vasoactive agents (n = 51, 1428 paired measurements, Bland-Altman analysis for agreement between invasive mean blood pressure (MBP) and non-invasive mean BP revealed a bias of -2.9123 mmHg (SD 7.8074). The 95% limits of agreement were from -18.2157 to 12.3893 mmHg. In preterm infants with hypotension, we detected a bias of -3.9176 mmHg (SD 5.1135) between invasive MBP and non-invasive MBP. The 95% limits of agreement were from -13.9401 to 6.1048 mmHg. In normotensive preterm infants receiving vasoactive agents, we detected a bias of -0.7629 mmHg (SD 8.0539) between invasive MBP and non-invasive MBP. The 95% limits of agreement were from -16.5485 to 15.02274 mmHg.

CONCLUSIONS

There is poor level of agreement between IBP and NIBP measurements in sick preterm neonates, leading to overestimation or underestimation of blood pressure. The bias was less for mean BP measurements as compared with systolic BP measurements and also for normotensive neonates as compared with hypotensive neonates. Hence, NIBP may be used as a screening method in haemodynamically stable preterm infants, but infants who are haemodynamically unstable and need to be commenced on vasoactive agents should have IBP monitoring.

Correction: Designing 3D-nanosubstrates mimicking biological cell growth: pitfalls of using 2D substrates in the evaluation of anticancer efficiency

Correction for 'Designing 3D-nanosubstrates mimicking biological cell growth: pitfalls of using 2D substrates in the evaluation of anticancer efficiency' by Ashwini Patil et al., Nanoscale, 2021, 13, 17473-17485, DOI: 10.1039/d1nr03816h.

Designing 3D-nanosubstrates mimicking biological cell growth: pitfalls of using 2D substrates in the evaluation of anticancer efficiency

Designing nano-substrates (NS) that support three-dimensional (3D) cell growth using physico-chemical interventions mimicking the cellular microenvironment is highly challenging. Here we report NS that assist 3D cell development (3D NS) using multi-components on a glass substrate (2D GS), which mimics the ex vivo tissue microenvironment and promotes 3D cell growth superior to conventional 2D cell culturing methodologies. 3D NS were chemically fabricated by linking the combination of advanced materials imparting different physico-chemical traits, for example, multiwalled carbon nanotubes (CNT), graphene (G), bovine serum albumin (BSA), and iron oxide magnetic nanoparticles (MNP). We compared cell-substrate interactions resulting in cellular morphological changes, influence on the cell circularity index (CI), nuclear-cytoplasmic ratios (N/C), and nuclear compression or derangements using human colorectal carcinoma cells (HCT116) and cervical cancer (HeLa) cells. We observed the increase in N/C, extended on the 3D NS micro-environment as indicative of cellular adaptation and the transformation. HCT116 and HeLa cells on 2D GS showed an N/C ratio <0.3, and 3D NS cultured cells exhibited a higher N/C ratio (>0.5). The most significant increase in the ratio, relative to arrested cell spreading, was observed with G-3D NS. Furthermore, 3D NS were evaluated for the cell viability differentiations using the anticancer drug doxorubicin (Dox). The drug-treated cells on 3D NS demonstrated far-displaced N/C ratios compared to 2D GS. In conclusion, 3D NS systems implicate an 'in vitro to in vivo' relevance for the outcome in cell biology, cell proliferation and migration, and in anticancer drug efficacy evaluation.

Circulating tumor cells demonstrate a positive biomarker in head and neck squamous cell carcinoma (HNSCC) in tobacco consuming population of Bangladesh

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Background: Tobacco consumption accounts for 1.6 million deaths annually in the South East Asia Region (SEAR). Notably, amongst 10-20% of the global population consuming the betel quid and tobacco, about 81% concentration is in SEAR regions, including India and Bangladesh. The prevalence of HNSCC in these regions is rising alarmingly. For example, HNCs account for 23% of total 156775 cancer incidences in Bangladesh. Liquid biopsy tools are unavailable and expensive for most patients in this region. However, early cancer detection using tumor biomarkers, for example, Circulating Tumor Cells (CTCs) is highly implicated. Furthermore, such biomarkers are being validated and have potential for screening of high-risk patients, such as genetic predisposition, tobacco consumption, etc. We report the first observational study in HNSCC patients in Bangladesh correlating the presence of CTCs to chronic tobacco consumption. Methods: The study involved 70 cancer patients and 10 healthy volunteers (no prior cancer history). 87% of the patients had a specified history of chronic tobacco consumption. CTCs were isolated in 1.5 ml of blood using OncoDiscover Liquid Biopsy Test, which is clinically approved by the Drug Controller General of India, that contains an enriching anti-EPCAM antibody immunomagnetic kit. CTCs are qualified as CK18+, DAPI+and CD45-. Subsequently, CTCs were imaged using Zeiss Axio Observer 7 and quantified for Mean Fluorescence Intensity (MFI) for clinicopathological parameters; age/gender, HNSCC sub-population, and CTC distribution. Results: This is the 1st study on Bangladesh phenotype accounting for the presence of CTCs in HNSCC patients. In this population, 34 males (66%) and 10 females (52%) accounted for 91 CTCs. CTC distribution was 0 to 6 with mean and median ̃ 2.02 and 2, respectively. 25 patients (17 males, 8 females) were negative for any CTCs. Interestingly, 02 patients exhibited CTC clusters indicative of aggressive metastasis in which 01 patient had no prior tobacco usage or family cancer history. There was no correlation between CTC presence in males (66 %) and females (52 %). Healthy volunteer samples exhibited no false positives. The MFI values ranged between 23 and 766, with mean and median MFI values were 157 and 96, respectively, indicative of CK overexpression on CTCs of HNSCC patients. Conclusions: HNSCC patients with a history of chronic tobacco consumption in Bangladesh correlated the presence of CTCs in 64 % of the cases. Prospectively, CTCs may be validated as a biomarker for screening chronic tobacco users in Bangladesh to detect early cancers and HNSCC. Clinical trial information: BMRC/Grants/2018/99 (1-100).

Chemo-specific designs for the enumeration of circulating tumor cells: advances in liquid biopsy

Advanced materials and chemo-specific designs at the nano/micrometer-scale have ensured revolutionary progress in next-generation clinically relevant technologies. For example, isolating a rare population of cells, like circulating tumor cells (CTCs) from the blood amongst billions of other blood cells, is one of the most complex scientific challenges in cancer diagnostics. The chemical tunability for achieving this degree of exceptional specificity for extra-cellular biomarker interactions demands the utility of advanced entities and multistep reactions both in solution and in the insoluble state. Thus, this review delineates the chemo-specific substrates, chemical methods, and structure-activity relationships (SARs) of chemical platforms used for isolation and enumeration of CTCs in advancing the relevance of liquid biopsy in cancer diagnostics and disease management. We highlight the synthesis of cell-specific, tumor biomarker-based, chemo-specific substrates utilizing functionalized linkers through chemistry-based conjugation strategies. The capacity of these nano/micro substrates to enhance the cell interaction specificity and efficiency with the targeted tumor cells is detailed. Furthermore, this review accounts for the importance of CTC capture and other downstream processes involving genotypic and phenotypic CTC analysis in real-time for the detection of the early onset of metastases progression and chemotherapy treatment response, and for monitoring progression free-survival (PFS), disease-free survival (DFS), and eventually overall survival (OS) in cancer patients.

A graphene-sandwiched DNA nano-system: regulation of intercalated doxorubicin for cellular localization

Control of the sub-cellular localization of nanoparticles (NPs) with enhanced drug-loading capacity, employing graphene oxide (GO), iron oxide (Fe₃O₄) NPs and sandwiched deoxyribonucleic acid (DNA) bearing intercalated anticancer drug doxorubicin (DOX) has been investigated in this work. The nanosystems G-DNA-DOX-Fe₃O₄ and Fe₃O₄-DNA-DOX differentially influence serum protein binding and deliver DOX to lysosomal compartments of cervical cancer (HeLa) cells with enhanced retention. Stern-Volmer plots describing BSA adsorption on the nanosystems demonstrated the quenching constants, K _sv for G-DNA-DOX-Fe₃O₄ and Fe₃O₄-DNA-DOX (0.025 mL μg^-1 and 0.0103 mL μg^-1 respectively). Nuclear DOX intensity, measured at 24 h, was ∼2.0 fold higher for Fe₃O₄-DNA-DOX in HeLa cells. Parallelly, the cytosol displayed ∼2.2 fold higher DOX intensity for Fe₃O₄-DNA-DOX compared to G-DNA-DOX-Fe₃O₄. Fe₃O₄-DNA-DOX was more efficacious in the cytotoxic effect than G-DNA-DOX-Fe₃O₄ (viability of treated cells: 33% and 49% respectively). The DNA:nanosystems demonstrated superior cytotoxicity compared to mole-equivalent free DOX administration. The results implicate DNA:DOX NPs in influencing the cellular uptake mechanism and were critically subject to cellular localization. Furthermore, cell morphology analysis evidenced maximum deformation attributed to free-DOX with 34% increased cell roundness, 63% decreased cell area and ∼1.9 times increased nuclear-to-cytoplasmic (N/C) ratio after 24 h. In the case of Fe₃O₄-DNA-DOX, the N/C ratio increased 1.2 times and a maximum ∼37% decrease in NSA was noted suggesting involvement of non-canonical cytotoxic pathways. In conclusion, the study makes a case for designing nanosystems with controlled and regulated sub-cellular localization to potentially exploit secondary cytotoxic pathways, in addition to optimized drug-loading for enhanced anticancer efficacy and reduced adverse effects.

Nanocarrier anticancer drug-conjugates cause higher cellular deformations: culpable for mischief

Here we report nanocarrier-anticancer drug conjugates culpable for cellular deformations, critically evidenced through image-based analysis as a measure of karyoplasmic ratio (KR) and nuclear surface area (NSA). Multiwalled carbon nanotubes (MWCNTs) were coordinated additionally with Fe3O4 nanoparticles (NPs) to evaluate the symbiotic influence, and further conjugated to Dox for evaluating the cellular kinetics and for measuring cell deformations. Cellular entry kinetics of the CNT (CNT-Dox and CNT-Cys-Fe3O4-Dox) nanocarriers and their efficiency in nuclear localization were evaluated using cervical cancer (HeLa) cells. Of note, the Dox-bound nanocarriers showed significantly enhanced cell toxicity over the free form of the drug. CNT-Dox and CNT-Cys-Fe3O4-Dox influx occurred within 4 hours, while maximum cellular retention of Dox was observed for CNT-Dox at 24 h. However, the highest KR (∼0.51) was observed for CNT-Dox within 8 hours indicating similar cellular deformations using nanocarrier anticancer drug-conjugates to that of free Dox (KR ∼0.50) at 4 hours. In addition, we observed increased NSA at 4 h in Dox treatment whereas in the case of the Dox conjugated nanocarrier, increased NSA was noted at 8 h treatment. At 8 h exposure of HeLa cells with Dox conjugates, we observed that the cells fall into distinct regions of the morphospace with respect to KR and NSA. Conclusively, nano delivery systems considered for clinical and biomedical translations must take into account the possible negative influences imparting higher cellular deformations and secondary adverse effects over the free form of the drug.

Cellulose Mediated Transferrin Nanocages for Enumeration of Circulating Tumor Cells for Head and Neck Cancer

Herein we report a hierarchically organized, water-dispersible 'nanocage' composed of cellulose nanocrystals (CNCs), which are magnetically powered by iron oxide (Fe₃O₄) nanoparticles (NPs) to capture circulating tumor cells (CTCs) in blood for head and neck cancer (HNC) patients. Capturing CTCs from peripheral blood is extremely challenging due to their low abundance and its account is clinically validated in progression-free survival of patients with HNC. Engaging multiple hydroxyl groups along the molecular backbone of CNC, we co-ordinated Fe₃O₄ NPs onto CNC scaffold, which was further modified by conjugation with a protein - transferrin (Tf) for targeted capture of CTCs. Owing to the presence of Fe₃O₄ nanoparticles, these nanocages were magnetic in nature, and CTCs could be captured under the influence of a magnetic field. Tf-CNC-based nanocages were evaluated using HNC patients' blood sample and compared for the CTC capturing efficiency with clinically relevant Oncoviu platform. Conclusively, we observed that CNC-derived nanocages efficiently isolated CTCs from patient's blood at 85% of cell capture efficiency to that of the standard platform. Capture efficiency was found to vary with the concentration of Tf and Fe₃O₄ nanoparticles immobilized onto the CNC scaffold. We envision that, Tf-CNC platform has immense connotation in 'liquid biopsy' for isolation and enumeration of CTCs for early detection of metastasis in cancer.

Abstract B30: Clinical correlation of circulating tumor cells as a blood marker in Indian head and neck cancer patients

Objectives: To establish a rapid, highly specific, efficient, sensitive, and affordable CTC enumeration liquid biopsy technology and to validate its efficacy to isolate CTC disseminating from epithelial tumors of HNC subpopulation in India. Furthermore, to study the correlation of CTC distribution from peripheral blood with respect to various clinicopathologic factors in these patients.

Materials and Methods: A cross-sectional study was conducted using peripheral blood from enrolled 350 HNC patients. CTC were isolated using DCGI, India-approved technology, that exploits EpCAM-based immunomagnetic separation. EpCAM+ tumor cells were isolated from only 1.5 mL blood and critically assayed for cytokeratin 18 (CK18) expression and quantified using fluorescence imaging of CTCs so as to obtain a threshold to further minimize nonspecific and false-positive enumeration. CTC enumeration was subsequently subjected to statistical correlation with various clinical and pathologic parameters.

Results: We detected CTCs from all HNC patients across its various subsites, and there was a minimum threshold of at least 12 CTC in early oral cancer patients according to their clinicopathologic signatures. Compared to early oral cancer patients, advanced nodal patients showed 40% escalation in CTC count, while up to 80% increase in CTC count was observed when associated with aggressive features such as lymphovascular emboli (LVE) and with extranodal extensions. Of note, laryngopharyngeal primary had the highest mean CTC count of 33 in 1.5mL blood. Conversely, patients with advanced disease had higher CTC count and this was staggered in comparison with nearly but not all of the clinical features. Remarkably, higher clinical N (nodal) stage statistically correlated with increased CTC count and a marked increase in CTC was seen in tumors that showed lymphovascular emboli on histopathology and extranodal extension. The CTC counts were independent of parameters such as the age, sex, T stage, perineural invasion, bone involvement, or skin involvement. There was a notable trend towards reduced CTC count after chemotherapy; however, it was not statistically significant.

Conclusion: Our rapid and efficient CTC platform has demonstrated and clinically validated its use in Indian HNC phenotypes. This is the first comprehensive study to show a staggering positive correlation of CTC with various clinicopathologic factors. It comprised the largest number of oral cancer patients throughout the entire spectrum of HNSCC, the most common cancer in India. High CTC counts among HNC patients could possibly be one of the reasons for their dismal outcomes, and further studies with a correlation of CTC with patient survival in HNC are warranted. However, this study strongly implicates a perspective utility of CTC as a tumor marker in establishing the clinical staging in HNC patients.

Citation Format: Jayant Khandare, Burhanuddin Nuruddin Qayyumi, Atul Bharde, Gourishankar Aland, Ajit Sagare, Swati Tripathi, Nitin Singh, Sreeja Jayant, Ashish Muglikar, Reecha Badave, Aravindan Vasudevan, Kumar Prabhash, Pankaj Chaturvedi. Clinical correlation of circulating tumor cells as a blood marker in Indian head and neck cancer patients [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B30.

Device for the enumeration and continuous removal of circulating tumor cells in improving overall survival of epithelial cancer patients

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Background: The presence of circulating tumor cells (CTC) in the vascular system is a tell-tale signature of metastasis in epithelial origin cancers including lung, breast, colorectal and head and neck cancers. Noteworthy, about 90% of cancer deaths are due to the progression of metastasis. Yet, cancer therapy is focussed on inhibiting tumour growth and there is a paucity of options that target metastasis. We demonstrate the POP ‘device’ that removes circulating tumour cells (CTC) from a patient’s blood to reduce the metastatic progression and improve overall survival. Methods: We designed, multi-component glass beads enriched antibody EpCAM conjugate substrates as POP blood fluidic device. We characterized the substrate and accounted for the biocompatibility using whole blood of healthy volunteers. We evaluated, the acute toxicity of substrates using rat (Wistar Albino) whole blood (CPCSEA registration number: 941/PO/Re/S/06/CPCSEA; 31/07/2019) and further studied major histopathological tissues for any toxicity. Finally, we evaluated 06 cancer patients whole blood (1.5 mL) for capturing and for the elimination of CTCs. The captured cells were immuno-stained, and the optimal fluorescence acquisition intensity was critically quantified in accounting CK18 protein over-expression. Results: The multi-component antibody EpCAM based substrate exhibited efficient CTC capture ability with a mean capture efficiency ranging from 40% to 100 % when compared to the OncoDiscover CTC test approved by CDSCO/ drug controller general of India (DCGI). Furthermore, the substrate indicated high biocompatibility primarily exhibited by the absence of haemolysis on whole human blood. Additionally, the preliminary animal experiments in rats showed a 100% survival rate and negligible toxicity to major organs. Conclusions: Removal of circulating tumor cells as a therapeutics is highly implicated in improving the overall survival of epithelial cancer patients.

Correlation of CTCs with disease progression in Indian oral cancer patients

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Background: Head and neck squamous cell carcinoma is leading cancer in the India with Oral squamous cell carcinoma (OSCC) as the most frequent subtype. OSCC is classified as a locoregional disease and its increased frequency is attributed to lack of good biomarkers compared to other epithelial cancers. At the time of diagnosis, above 50% of cases present the manifestation of advanced-stage disease, and are predisposed to disease failure in spite of appropriate treatment. Thus, early diagnosis of OSCC can significantly reduce the disease burden. Here we describe regulatory approved method to establish Circulating tumor cells (CTCs) presence in OSCC Indian patients and its positive correlation with various clinicopathological parameters, suggesting the potential use of CTCs as a significant parameter to stratify oral cancer with respect to the disease advancement. Methods: In a cross-sectional observational study, 230 OSCC patients at the different pathological stage of the disease and treatment mode were enrolled. CTCs were isolated using approved OncoDiscover liquid biopsy technology (Drug controller general of India approved), platform technology based on immunomagnetic CTC enumeration. CTCs were detected for CK18 presence and well-defined, DAPI-stained nuclei. Enumerated CTC subsequently analyzed for various clinic-pathological parameters such as pstage, extra-capsular spread (ECS), lymphovascular emboli (LVE), perineural invasion (PNI) and depth of invasion (DOI). CTC cut off values were obtained to differentiate early vs advanced stages with respect to different clinical stages and parameters. Results: CTCs of OSCC patients correlated positively with the cancer stages (clinical as well as pathological) as well as aggressive pathological features. The presence of aggressive pathological features that often suggest the poor outcome of the disease, we observed a 25-50 % increase in CTC number. Early stage, treatment naïve patients had lower number of CTCs. Mean CTC number in advanced-stage patients was 50 % higher than early-stage OSCC patients. Conclusions: Considering a positive correlation of CTC number with various pathophysiological features, CTC can be contemplated as a reliable parameter to predict the disease outcome in oral cancer. The consistent presence of CTC across all disease stages also suggests a probable nature of OSCC as a biological systematic disease. Clinical trial information: CTRI/2018/03/012905.

Is Routine Monitoring for Hypoglycemia Required in Intramural Asymptomatic Infant of Diabetic Mother? An Audit in a Tertiary Care Hospital

AIMS

This retrospective audit aimed to analyze whether routine frequent monitoring for hypoglycemia is required in asymptomatic infant of diabetic mother born in tertiary care hospital.

METHODS

The study analyzed the blood sugar level of 196 infants of diabetic mothers.

RESULTS

The overall incidence of hypoglycemia from 196 study participants was 9.18% (N = 18). The incidence of hypoglycemia at 2 h of life was maximum (83.33%) and it was significant when compared to 3, 6, 9 and 12 h (p < 0.0001). Blood glucose levels were significantly more at 6 (p = 0.0002)), 9 (p = 0.0001) and 12 h (p = 0.0001) when compared to glucose level at 2 h except at 3 h of life (p = 0.062). Similarly blood glucose at 9 (p = 0.0001) and 12 h of life (p = 0.0002) were significantly more than at 3 h of life. Blood glucose at 9 h was significantly more than at 6 h of life (0.032) and at 12 hours of life (p = 0.0237) was significantly higher than at 6 h of life.

CONCLUSION

The frequent blood glucose monitoring for hypoglycemia in infant of diabetic mother as per American Academy of Pediatrics may be reduced as per the findings in our study. However, this needs to be confirmed by a properly designed observational study/adequately powered randomized controlled trial.

A highly efficient, low-cost, novel multicomponent nanosystem for rapid enumeration of circulating tumor cells

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Background: ‘Liquid biopsy’ technologies are unaffordable and unavailable in developing countries despite having highest cancer burden and mortality rates. Current Circulating Tumor Cell (CTCs) technologies sustain clinical concerns of a) non-specificity b) low efficiency c) high blood volume requirement d) long turn-around time, and d) exorbitant cost (~$900-1400). We report, an extremely low cost, innovative nanosystem for rapid enumeration of CTS with higher specificity and efficiency. Methods: We designed a nanosystem mediated by conjugation of anti-EpCAM through multi-reactive glutathione spacer, carbon allotrope and amine terminated dendrimer. The platform was evaluated for enhanced aqueous dispersibility and increased interaction with CTCs for rapid isolation and enumeration in 100 Head and Neck Cancer (HNC) patients having primary tumor sub-sites-oral cavity, larynx, hypopharynx, oropharynx, nasopharynx, salivary gland, and thyroid. The captured cells were immuno-stained and the optimal fluorescence acquisition intensity was validated in accounting CTCs with CK18 protein expression. There was complete elimination of the false positive normal cells (NC) count to CTCs by our method. The analysis was performed with only 1.5 ml of collected blood samples. Results: The CTC distribution in cohort study ranged from 1 - 85 cells per 1.5 mL of blood. In more than 80% of patient’s CTCs, the quantitative estimation of anti-CK18 protein over-expression indicated ~10-fold higher intensity over to NCs. As compared to treatment naive, recurrent, and disease-free patients, the spread of CTC number across the clinical range appeared to be tight (close to mean value). The CTC enumeration sensitivity linearity was ~99.2%, and the complete enumeration process time was under 03 hours/1.5 ml of blood. Consequently, efficient, rapid and yet affordable CTC platform was designed and clinically validated. Conclusions: ‘OncoDiscover’ liquid biopsy technology for CTC enumeration is poised to revolutionize the liquid biopsy due to its high sensitivity and affordability (~ $120) and shall resolve a major unmet medical need in impoverished world.

Optimizing Circulating Tumor Cells' Capture Efficiency of Magnetic Nanogels by Transferrin Decoration

Magnetic nanogels (MNGs) are designed to have all the required features for their use as highly efficient trapping materials in the challenging task of selectively capturing circulating tumor cells (CTCs) from the bloodstream. Advantageously, the discrimination of CTCs from hematological cells, which is a key factor in the capturing process, can be optimized by finely tuning the polymers used to link the targeting moiety to the MNG. We describe herein the relationship between the capturing efficiency of CTCs with overexpressed transferrin receptors and the different strategies on the polymer used as linker to decorate these MNGs with transferrin (Tf). Heterobifunctional polyethylene glycol (PEG) linkers with different molecular weights were coupled to Tf in different ratios. Optimal values over 80% CTC capture efficiency were obtained when 3 PEG linkers with a length of 8 ethylene glycol (EG) units were used, which reveals the important role of the linker in the design of a CTC-sorting system.

New approaches from nanomedicine for treating leishmaniasis

This review summarizes the recent progress in nanomedicine for the treatment of leishmaniasis.

Transferrin Decorated Thermoresponsive Nanogels as Magnetic Trap Devices for Circulating Tumor Cells

A rational design of magnetic capturing nanodevices, based on a specific interaction with circulating tumor cells (CTCs), can advance the capturing efficiency and initiate the development of modern smart nanoformulations for rapid isolation and detection of these CTCs from the bloodstream. Therefore, the development and evaluation of magnetic nanogels (MNGs) based on magnetic nanoparticles and linear thermoresponsive polyglycerol for the capturing of CTCs with overexpressed transferrin (Tf(+) ) receptors has been presented in this study. The MNGs are synthesized using a strain-promoted "click" approach which has allowed the in situ surface decoration with Tf-polyethylene glycol (PEG) ligands of three different PEG chain lengths as targeting ligands. An optimal value of around 30% of cells captures is achieved with a linker of eight ethylene glycol units. This study shows the potential of MNGs for the capture of CTCs and the necessity of precise control over the linkage of the targeting moiety to the capturing device.

Dendritic polyglycerol sulfate as a novel platform for paclitaxel delivery: pitfalls of ester linkage

In this study, dendritic polyglycerol sulfate (dPGS) is evaluated as a delivery platform for the anticancer, tubulin-binding drug paclitaxel (PTX). The conjugation of PTX to dPGS is conducted via a labile ester linkage. A non-sulfated dendritic polyglycerol (dPG) is used as a control, and the labeling with an indocarbocyanine dye (ICC) renders multifunctional conjugates that can be monitored by fluorescence microscopy. The conjugates are characterized by (1)H NMR, UV-vis measurements, and RP-HPLC. In vitro cytotoxicity of PTX and dendritic conjugates is evaluated using A549 and A431 cell lines, showing a reduced cytotoxic efficacy of the conjugates compared to PTX. The study of uptake kinetics reveals a linear, non saturable uptake in tumor cells for dPGS-PTX-ICC, while dPG-PTX-ICC is hardly taken up. Despite the marginal uptake of dPG-PTX-ICC, it prompts tubulin polymerization to a comparable extent as PTX. These observations suggest a fast ester hydrolysis and premature drug release, as confirmed by HPLC measurements in the presence of plasma enzymes.

Comparative anti-inflammatory activity of poly(amidoamine) (PAMAM) dendrimer-dexamethasone conjugates with dexamethasone-liposomes

Lipophilicity vs hydrophicility physicochemical traits are extremely important variables that are active considerations for optimizing drug delivery systems. The comparative anti-inflammatory delivery potential of dexamethasone (dex) in an encapsulation-based (liposome-lipophilic) and poly (amidoamine) (PAMAM) dendrimer prodrug conjugation-based delivery systems (hydrophilic) was performed in this work. Dendrimer prodrug conjugates were characterized by (1)H NMR. The drug encapsulation efficiency for drug in liposomes was observed to be 14.02% and this was correlated with a dose-dependent tumor necrosis factor (TNF)-α inhibition (39-57% inhibition). The biological evaluation of nanocarriers for drug was demonstrated in a standard, conventionally used in vitro cell-based system for TNF-α inhibition. This served as a comparative tool to demonstrate a quantitatively higher TNF-α inhibition (67-71.48%) produced by the dendrimer-dex drug conjugate. The structure activity relationship (dose-for-dose) was inferred by relatively lesser inhibition of TNF-α by variants of PAMAM G4 (NH2) dendrimer-dex conjugates and was compared with liposomes carrying dex. In vitro results suggest that the prodrug conjugates of PAMAM dendrimer deliver dex to be more efficient in comparison with liposome-based dex in terms of higher TNF-α inhibition. This study has implications in designing efficient prodrug nanocarrier systems for delivering dex.

Cellular imaging using biocompatible dendrimer-functionalized graphene oxide-based fluorescent probe anchored with magnetic nanoparticles

We describe a novel multicomponent graphene nanostructured system that is biocompatible, and has strong NIR optical absorbance and superparamagnetic properties. The fabrication of the multicomponent nanostructure system involves the covalent attachment of 3 components; Fe(3)O(4)(Fe) nanoparticles, PAMAM-G4-NH(2) (G4) dendrimer and Cy5 (Cy) on a graphene oxide (GO) surface to synthesize a biologically relevant multifunctional system. The resultant GO-G4-Fe-Cy nanosystem exhibits high dispersion in an aqueous medium, and is magnetically responsive and fluorescent. In vitro experiments provide a clear indication of successful uptake of the GO-G4-Fe-Cy nanosystem by MCF-7 breast cancer cells, and it is seen to behave as a bright and stable fluorescent marker. The study also reveals varied cellular distribution kinetics profile for the GO nanostructured system compared to free Cy. Furthermore, the newly developed GO nanostructured system is observed to be non-toxic to MDA-MB-231 cell growth, in striking contrast to free G4 dendrimer and GO-G4 conjugate. The GO-G4-Fe-Cy nanostructured system characterized by multifunctionality suggests the merits of graphene for cellular bioimaging and the delivery of bioactives.

Enhancing surface interactions with colon cancer cells on a transferrin-conjugated 3D nanostructured substrate

A transferrin-conjugated PEG-Fe(3) O(4) nanostructured matrix is developed to explore cellular responses in terms of enhanced cell adhesion, specific interactions between ligands in the matrix and molecular receptors on the cell membrane, comparison of cell shapes on 2D and 3D surfaces, and effect of polymer architecture on cell adhesion. Integration of such advanced synthetic nanomaterials into a functionalized 3D matrix to control cell behavior on surfaces will have implications in nanomedicine.

Multifunctional dendritic polymers in nanomedicine: opportunities and challenges

Nanotechnology has resulted in materials that have greatly improved the effectiveness of drug delivery because of their ability to control matter on the nanoscale. Advanced forms of nanomedicine have been synthesized for better pharmacokinetics to obtain higher efficacy, less systemic toxicity, and better targeting. These criteria have long been the goal in nanomedicine, in particular, for systemic applications in oncological disorders. Now, the "holy grail" in nanomedicine is to design and synthesize new advanced macromolecular nanocarriers and to translate them from lab to clinic. This review describes the current and future perspectives of nanomedicine with particular emphasis on the clinical targets in cancer and inflammation. The advanced forms of liposomes and polyethylene glycol (PEG) based nanocarriers, as well as dendritic polymer conjugates will be discussed with particular attention paid to designs, synthetic strategies, and chemical pathways. In this critical review, we also report on the current status and perspective of dendritic polymer nanoconjugate platforms (e.g. polyamidoamine dendrimers and dendritic polyglycerols) for cellular localization and targeting of specific tissues (192 references).

Size-dependant cellular uptake of dendritic polyglycerol

To study the mechanism of cellular internalization, hyperbranched polyether derivatives consisting of amino-bearing hyperbranched polyglycerols (HPGs) of varied molecular mass and size range are designed and synthesized. HPGs were further fluorescently labelled by conjugating maleimido indocarbocyanine dye (ICC-mal). The conjugates are characterized by UV-vis spectroscopy, fluorescence profile, zeta potential, and dynamic light scattering. The uptake mechanism is studied by fluorescence-activated cell sorting (FACS) analysis, fluorescence spectroscopy, and confocal microscopy with human lung cancer cells A549, human epidermoid carcinoma cells A431, and human umbilical vein endothelial cells (HUVEC) cells. For the first time, the results suggest that the higher-molecular-weight HPGs (40-870 kDa) predominantly accumulate in the cytoplasm much better than their low-molecular-weight counterparts (2-20 kDa). The HPG nanocarriers discussed here have many biomedical implications, particularly for delivering drugs to the targeted site.

Effects of branching architecture and linker on the activity of hyperbranched polymer-drug conjugates

Drug release from hyperbranched polymer-drug conjugates and the subsequent activity are influenced by the branching architecture and the linker. To gain an understanding of these effects, we used hyperbranched polyol and G4-OH polyamidoamine (PAMAM) dendrimer with methyl prednisolone (MP) as the model drug. The drug was conjugated to dendrimer or polyol using a glutaric acid (GA) or a succinic acid (SA) spacer. Drug payload was the highest with polyol, while in the case of dendrimer, a higher payload was achieved with the GA than the SA spacer. Cell uptake of the polymer conjugates in A549 lung epithelial cells was higher than that of the free drug, and the conjugates largely localized in the cytosol. The anti-inflammatory activity of polymer conjugated MP, as measured by inhibition of prostaglandin synthesis, was the highest for MP-SA-dendrimer conjugate, followed by MP-GA-polyol conjugate, and then MP-GA-dendrimer conjugate. This study suggests that the branching architecture and spacer influence the drug payload and pharmacological activity of a drug-nanopolymer conjugate, which may significantly influence the in vivo efficacy of these nanodevices. This has key implications in the eventual in vivo efficacy of these nanodevices.

Pharmaceutically used polymers: principles, structures, and applications of pharmaceutical delivery systems

This chapter presents a general overview of pharmaceutically used polymers with respect to their physicochemical characteristics and factors affecting drug delivery abilities. Pharmaceutical polymers, chemical structure, and properties are discussed for their applications in controlled drug release systems. An additional focus is on new polymers (dendrimers, hyperbranched polymers), considering their chemical versatility, uniqueness, and future implications. Problems associated with controlled drug release systems are also highlighted. Finally, applications of FDA-approved polymers used for oral drug delivery systems are outlined.

Targeted Proapoptotic Anticancer Drug Delivery System

A novel targeted proapoptotic anticancer drug delivery system (DDS) was developed and evaluated both in vitro and in vivo. The system contains poly(ethylene glycol) polymer (PEG) as a carrier, camptothecin (CPT) as an anticancer drug/cell death inducer, a synthetic analogue of luteinizing hormone-releasing hormone (LHRH) peptide as a targeting moiety/penetration enhancer, and a synthetic analogue of BCL2 homology 3 domain (BH3) peptide as a suppressor of cellular antiapoptotic defense. The design of the multicomponent DDS allowed for a conjugation of one or two copies of each active ingredient (CPT, LHRH, and BH3) to one molecule of PEG carrier. The complex structure of the PEG conjugates was visualized at nanometer resolution using atomic force microscopy. We found that the ligand-targeted DDS for cancer cells preferentially accumulated in the tumor and allowed the delivery of active ingredients into the cellular cytoplasm and nuclei of cancer cells. Simultaneous apoptosis induction through the caspase-dependent signaling pathway and inhibition of cellular antiapoptotic defense by the suppression of BCL2 protein enhanced cytotoxicity and antitumor activity of the entire DDS to a level which could not be achieved by individual components applied separately. The DDS containing two copies of each active component (CPT, LHRH, and BH3) per molecule of PEG polymer had the highest anticancer efficiency in vitro and in vivo.

Activity of Dendrimer−Methotrexate Conjugates on Methotrexate-Sensitive and -Resistant Cell Lines

Dendritic nanostructures can play a key role in drug delivery, due to the high density and variety of surface functional groups that can facilitate and modulate the delivery process. We have investigated the effect of dendrimer end-functionality on the activity of polyamido amine (PAMAM) dendrimer-methotrexate (MTX) conjugates in MTX-sensitive and MTX-resistant human acute lymphoblastoid leukemia (CCRF-CEM) and Chinese hamster ovary (CHO) cell lines. Two amide-bonded PAMAM dendrimer-MTX conjugates were prepared using a dicyclohexylcarbodiimide (DCC) coupling reaction: one between a carboxylic acid-terminated G2.5 dendrimer and the amine groups of the MTX (conjugate A) and another between an amine-terminated G3 dendrimer and the carboxylic acid group of the MTX (conjugate B). Our studies suggest that conjugate A showed an increased drug activity compared to an equimolar amount of free MTX toward both sensitive and resistant cell lines, whereas conjugate B did not show significant activity on any of the cell lines. Despite substantially impaired MTX transport by MTX-resistant CEM/MTX and RII cells, conjugate A showed sensitivity increases of approximately 8- and 24-fold (based on IC50 values), respectively, compared to free MTX. Co-incubation of the cells with adenosine and thymidine along with either conjugate A or MTX resulted in almost complete protection, suggesting that the conjugate achieves its effect on dihyrofolate reductase (DHFR) enzyme through the same mechanism as that of MTX. The differences in cytotoxicity of these amide-bonded conjugates may be indicative of differences in the intracellular drug release from the cationic dendrimer (conjugate B) versus the anionic dendrimer (conjugate A), perhaps due to the differences in lysosomal residence times dictated by the surface functionality. These findings demonstrate the feasibility of using dendrimers as drug delivery vehicles for achieving higher therapeutic effects in chemotherapy, especially in drug-resistant cells.

Preparation, cellular transport, and activity of polyamidoamine-based dendritic nanodevices with a high drug payload

Dendrimers are emerging as a relatively new class of polymeric biomaterials with applications in drug delivery, and imaging. Achieving a high drug payload in dendrimers, and understanding the therapeutic effect of the dendrimer-drug conjugates are receiving increasing attention. A high drug payload nanodevice was obtained by covalent conjugation of ibuprofen to a polyamidoamine (PAMAM-G4-OH) dendrimer. Using DCC as a coupling agent, 58 molecules of ibuprofen were covalently conjugated to one molecule of generation 4 PAMAM-OH dendrimer. Cellular entry of the fluoroisothiocynate (FITC)-labeled dendrimer-drug conjugate was evaluated in vitro by using human lung epithelial carcinoma A549 cells by flow cytometry, confocal microscopy and UV/Visible spectroscopy. The pharmacological activity of the dendrimer-ibuprofen conjugate was compared to pure ibuprofen at various time points by measuring the suppression of prostaglandin E2. Significant amounts of the conjugate entered the cells rapidly within 15 min. Suppression of prostaglandin was noted within 30 min for the dendrimer-drug conjugates versus 1 h for the free ibuprofen. The results suggest that dendrimers with high drug payload improve the drug's efficacy by enhanced cellular delivery, and may produce a rapid pharmacological response. These dendrimer-drug conjugates can potentially be further modified by attaching antibodies and ligands for targeted drug delivery.