Efficient separation of large particles and giant cancer cells using an isosceles trapezoidal spiral microchannel.

Polyploid giant cancer cells (PGCCs) contribute to the genetic heterogeneity and evolutionary dynamics of tumors. Their size, however, complicates their isolation from mainstream tumor cell populations. Standard techniques like fluorescence-activated cell sorting (FACS) rely on fluorescent labeling, introducing potential challenges in subsequent PGCC analyses. In response, we developed the Isosceles Trapezoidal Spiral Microchannel (ITSµC), a microfluidic device optimizing the Dean drag force (FD) and exploiting uniform vortices for enhanced separation. Numerical simulations highlighted ITSµC's advantage in producing robust FD compared to rectangular and standard trapezoidal channels. Empirical results confirmed its ability to segregate larger polystyrene (PS) particles (avg. diameter: 50 µm) toward the inner wall, while directing smaller ones (avg. diameter: 23 µm) outward. Utilizing ITSµC, we efficiently isolated PGCCs from doxorubicin-resistant triple-negative breast cancer (DOXR-TNBC) and patient-derived cancer (PDC) cells, achieving outstanding purity, yield, and viability rates (all greater than 90%). This precision was accomplished without fluorescent markers, and the versatility of ITSµC suggests its potential in differentiating a wide range of heterogeneous cell populations.

A multicentre, randomised, open-label, parallel-group Phase 2b study of belotecan versus topotecan for recurrent ovarian cancer.

BACKGROUND: This Phase 2b study compared the efficacy and toxicity of belotecan and topotecan in recurrent ovarian cancer. METHODS: Patients with platinum-sensitive recurrent or platinum-resistant recurrent ovarian cancer (PRROC) were randomised 1:1 to receive belotecan 0.5 mg/m2 or topotecan 1.5 mg/m2 for five consecutive days every 3 weeks. The primary endpoint was overall response rate (ORR); secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. RESULTS: A total of 140 (belotecan, n = 71; topotecan, n = 69) and 130 patients (belotecan, n = 66; topotecan, n = 64) were included in the intention-to-treat (ITT) and per-protocol (PP) populations. ORR did not differ significantly between the belotecan and topotecan groups (ITT, 29.6% versus 26.1%; PP, 30.3% versus 25%). Although PFS did not differ between the groups, belotecan was associated with improved OS compared with topotecan in the PP population (39.7 versus 26.6 months; P = 0.034). In particular, belotecan showed longer OS in PRROC and non-high-grade serous carcinoma (non-HGSC; PP, adjusted hazard ratios, 0.499 and 0.187; 95% confidence intervals 0.255-0.977 and 0.039-0.895). Furthermore, there were no differences in toxicities between the two groups. CONCLUSIONS: Belotecan was not inferior to topotecan in terms of overall response for recurrent ovarian cancer. CLINICAL TRIAL REGISTRATION: NCT01630018.

Dual anode single-photon avalanche diode for high-speed and low-noise Geiger-mode operation.

The after-pulsing effect is a common problem in high-speed and low-noise single-photon detection based on single-photon avalanche diodes (SPADs). This article presents a dual anode InGaAs/InP SPAD (DA-SPAD) with two separate anode output ports that can be utilized for discriminating relatively weak avalanche signals, providing a simple and robust configuration of the SPAD-based single-photon detection system. Weak avalanche signals with amplitudes below the amplitude of the parasitic capacitive response of the SPAD were easily detected by the DA-SPAD and a simple subtraction circuit. The gated Geiger-mode performance of the DA-SPAD was also investigated. At a gating frequency of 1 GHz, the detection efficiency was 20.4% with an after-pulse probability of 3.5% at a temperature of -20 °C.

Dual Mechanism of Action of 5-Nitro-1,10-Phenanthroline against Mycobacterium tuberculosis.

New chemotherapeutic agents with novel mechanisms of action are urgently required to combat the challenge imposed by the emergence of drug-resistant mycobacteria. In this study, a phenotypic whole-cell screen identified 5-nitro-1,10-phenanthroline (5NP) as a lead compound. 5NP-resistant isolates harbored mutations that were mapped to fbiB and were also resistant to the bicyclic nitroimidazole PA-824. Mechanistic studies confirmed that 5NP is activated in an F420-dependent manner, resulting in the formation of 1,10-phenanthroline and 1,10-phenanthrolin-5-amine as major metabolites in bacteria. Interestingly, 5NP also killed naturally resistant intracellular bacteria by inducing autophagy in macrophages. Structure-activity relationship studies revealed the essentiality of the nitro group for in vitro activity, and an analog, 3-methyl-6-nitro-1,10-phenanthroline, that had improved in vitro activity and in vivo efficacy in mice compared with that of 5NP was designed. These findings demonstrate that, in addition to a direct mechanism of action against Mycobacterium tuberculosis, 5NP also modulates the host machinery to kill intracellular pathogens.

Intersubband transition in lattice-matched BGaN/AlN quantum well structures with high absorption coefficients.

Intersubband absorption properties of lattice-matched BGaN/AlN quantum well (QW) structures grown on AlN substrate are theoretically investigated using an effective mass theory considering the nonparabolicity of the conduction band. These results are compared with those of GaN/AlN QW structures. The intersubband absorption coefficient of the BGaN/AlN QW structure is shown to be enhanced significantly, compared to that of the conventional GaN/AlN QW structure. This can be explained by the fact that the BGaN/AlN QW structure exhibits larger intersuband dipole moment and quasi-Fermi-level separation than the GaN/AlN QW structure, due to the increase in the carrier confinement by a larger internal field. We expect that the BGaN/AlN QW structure with a high absorption coefficient can be used for telecommunication applications at 1.55 µm under the lattice-matched condition, instead of the conventional GaN/AlN QW structure with the large strain.

Effect of number of retrieved lymph nodes on prognosis in FIGO stage IB-IIA cervical cancer patients treated with primary radical surgery.

AIM: In the treatment of cervical cancer, the extent of lymphadenectomy is a matter of debate. The goal of the current study was to examine the question of whether the number of retrieved lymph nodes (RLN) can influence survival of patients with early stage cervical cancer. METHODS: The medical records of 180 FIGO stage IB-IIA cervical cancer patients treated with primary radical surgery were reviewed. Patients were divided into two groups: those with ≤ 40 RLN and those with > 40 RLN. Patients were also assigned to either the bulky (tumor size > 4 cm) cervical cancer group or the non-bulky (tumor size ≤ 4 cm) cervical cancer group. RESULTS: The number of RLN had a statistically significant effect on both disease-free survival (P = 0.04) and overall survival (P = 0.02) of all patients. Patients with > 40 RLN had better prognoses than those with ≤ 40 RLN. In the bulky cervical cancer group, the number of RLN was an independent prognostic factor. In multivariate analysis for the bulky cervical cancer group, > 40 RLN had a significant positive effect on disease-free survival (adjusted hazard ratio, 0.36; 95% confidence interval, 0.13-0.97) and overall survival (adjusted hazard ratio, 0.23; 95% confidence interval, 0.06-0.90). However, number of RLN was not an independent prognostic factor in the non-bulky cervical cancer group. CONCLUSIONS: A more extensive lymphadenectomy increased the survival of bulky cervical cancer patients. This finding may be helpful in determining surgical extent before surgery for cervical cancer.

Metabolic components and recurrence in early-stage cervical cancer.

Epidemiological evidence suggests that the metabolic syndrome (MetS) is associated with increased risk of cervical cancer. However, research on the impact of MetS on prognosis in cervical cancer is lacking. This study investigated the association between MetS and recurrence-free survival (RFS) in patients with early-stage cervical cancer. This is a retrospective study of patients diagnosed with the International Federation of Gynecology and Obstetrics (FIGO) stage I-II cervical cancer in three tertiary hospitals during 2006-2009. Cox proportional hazards model was used to estimate the association between MetS or MetS components and RFS. We were able to evaluate MetS status in 84 patients out of 127. Forty patients had MetS. RFS was not significantly different according to MetS status; however, there was no further event of recurrence in non-MetS group after 2 years from primary surgical treatment. Hypertriglyceridemia (HR 3.67, 95% CI 1.18-11.43) and impaired fasting glucose (HR 4.30, 95% CI 1.23-15.03) were independent risk factors for shorter RFS, after adjustment for age, lymph node involvement, tumor involvement of resection margin, parametrial invasion, FIGO stage at diagnosis, and adjuvant treatment. Hypertriglyceridemia and impaired fasting glucose were associated with higher risk of recurrence in patients with early-stage cervical cancer. Prospective validation in large populations and further studies on the impact of MetS treatment in patients with cervical cancer are warranted.

Synthesis and anti-tubercular activity of 2-nitroimidazooxazines with modification at the C-7 position as PA-824 analogs.

Tuberculosis (TB) is a major global health problem, and new drug targets and scaffolds need to be identified to combat the emergence of drug resistant TB. The nitroimidazooxazine PA-824 represents a new class of bio-reductive drug to treat TB. In this study we report a 2-nitroimidazooxazine derivative with modification at the C-7 position that exhibited better activity than PA-824 against Mycobacterium tuberculosis (Mtb) H37Rv strain in vitro. From 7a as a key intermediate, we functionalized with benzyl ether (8), phenyl ether (9), benzyl carbonate (10) and benzyl carbamate (11). Among the 23 compounds produced, 8a-R (MIC=0.078 µM) with trifluoromethoxy benzyl group was 5-fold more potent than PA-824 (MIC=0.390 µM) in the in vitro assays against the wild-type Mtb, and the phenyl ether compound 9g-R (MIC=0.050 µM) exhibited the most potent antimycobacterial activity.

A Web-based nomogram predicting para-aortic nodal metastasis in incompletely staged patients with endometrial cancer: a Korean Multicenter Study.

OBJECTIVE: The purpose of this study is to develop a Web-based nomogram for predicting the individualized risk of para-aortic nodal metastasis in incompletely staged patients with endometrial cancer. METHODS: From 8 institutions, the medical records of 397 patients who underwent pelvic and para-aortic lymphadenectomy as a surgical staging procedure were retrospectively reviewed. A multivariate logistic regression model was created and internally validated by rigorous bootstrap resampling methods. Finally, the model was transformed into a user-friendly Web-based nomogram (http://http://www.kgog.org/nomogram/empa001.html). RESULTS: The rate of para-aortic nodal metastasis was 14.4% (57/397 patients). Using a stepwise variable selection, 4 variables including deep myometrial invasion, non-endometrioid subtype, lymphovascular space invasion, and log-transformed CA-125 levels were finally adopted. After 1000 repetitions of bootstrapping, all of these 4 variables retained a significant association with para-aortic nodal metastasis in the multivariate analysis-deep myometrial invasion (P = 0.001), non-endometrioid histologic subtype (P = 0.034), lymphovascular space invasion (P = 0.003), and log-transformed serum CA-125 levels (P = 0.004). The model showed good discrimination (C statistics = 0.87; 95% confidence interval, 0.82-0.92) and accurate calibration (Hosmer-Lemeshow P = 0.74). CONCLUSIONS: This nomogram showed good performance in predicting para-aortic metastasis in patients with endometrial cancer. The tool may be useful in determining the extent of lymphadenectomy after incomplete surgery.

Lymph node status did not significantly improve the predictability of survival in patients with clinically early-stage endometrial cancer.

OBJECTIVE: The aim of this study was to determine whether knowledge of lymph node status improves survival prediction in clinically early-stage endometrial cancer. METHODS: The records of 661 patients with apparently uterine-confined disease were reviewed. The performance in predicting overall survival and cause-specific survival was compared between a multivariate prognostic model with nodal status and a model without nodal status by calculating Harrell concordance index. RESULTS: Among 661 patients with clinically early-stage endometrial cancer, the lymph node metastasis rate was 8.3% (55/661). Lymph node metastasis independently associated with cause-specific survival only when no stratification according to adjuvant treatment was applied (P = 0.035). After stratification according to adjuvant radiotherapy, lymph node status marginally associated with cause-specific survival (P = 0.073), whereas myometrial invasion retained its strong association with cause-specific survival (P < 0.001). However, there was no significant difference in the performance of the survival model using only uterine factors and the model using lymph node status and uterine factors (concordance index, 0.77 vs 0.77, respectively; P = 0.798). CONCLUSIONS: Knowledge of lymph node status did not significantly improve the performance of survival prediction in apparently uterine-confined endometrial cancer, although it was independently associated with survival. In the patients with clinically early-stage endometrial cancer, the accuracy of the prediction of survival was comparable between risk grouping without lymph node status and that including lymph node status.

Plant-Derived Anti-Human Epidermal Growth Factor Receptor 2 Antibody Suppresses Trastuzumab-Resistant Breast Cancer with Enhanced Nanoscale Binding.

Traditional monoclonal antibodies such as Trastuzumab encounter limitations when treating Human Epidermal Growth Factor Receptor 2 (HER2)-positive breast cancer, particularly in cases that develop resistance. This study introduces plant-derived anti-HER2 variable fragments of camelid heavy chain domain (VHH) fragment crystallizable region (Fc) KEDL(K) antibody as a potent alternative for overcoming these limitations. A variety of biophysical techniques, in vitro assays, and in vivo experiments uncover the antibody's nanoscale binding dynamics with transmembrane HER2 on living cells. Single-molecule force spectroscopy reveals the rapid formation of two robust bonds, exhibiting approximately 50 pN force resistance and bond lifetimes in the second range. The antibody demonstrates a specific affinity for HER2-positive breast cancer cells, including those that are Trastuzumab-resistant. Moreover, in immune-deficient mice, the plant-derived anti-HER2 VHH-FcK antibody exhibits superior antitumor activity, especially against tumors that are resistant to Trastuzumab. These findings underscore the plant-derived antibody's potential as an impactful immunotherapeutic strategy for treating Trastuzumab-resistant HER2-positive breast cancer.

Outcomes of ovarian preservation in a cohort of premenopausal women with early-stage endometrial cancer: a Korean Gynecologic Oncology Group study.

OBJECTIVE: The aim of this study was to evaluate the impact of ovarian preservation on the recurrence and survival rates of premenopausal women with early-stage endometrial cancer. METHODS: Using medical records of premenopausal women who received primary surgical treatment for stage I-II endometrial cancer, the demographics and survival rates were compared retrospectively for patients who had ovarian preservation and those who underwent bilateral salpingo-oophorectomy. Cox proportional hazards models with inverse probability of treatment weighting (IPTW) based on propensity score were performed to adjust for selection bias between the two groups. RESULTS: A total of 495 women were identified, including 176 patients who had ovarian preservation. The ovarian preservation group was younger (P<0.001) and had an earlier year of diagnosis (P=0.014), a lower prevalence of lymphadenectomy (P<0.001), and a marginally significant association with lower tumor grade (P=0.052). The Kaplan-Meier curve and the log rank test showed no difference in either recurrence-free survival (P=0.742) or overall survival (P=0.462) between the two groups. In a multivariate Cox model adjusted by IPTW and covariates, ovarian preservation had no effect on either recurrence (hazard ratio [HR], 0.73; 95% CI, 0.29-1.81) or overall survival (HR, 1.33; 95% CI, 0.43-4.09). CONCLUSIONS: Ovarian preservation does not appear to be associated with an adverse impact on the outcomes of premenopausal women with early-stage endometrial cancer. The present study has useful implications for physicians counseling young women who want to preserve their ovaries.

Clinical and histopathological features of lentigo maligna and lentigo maligna melanoma: a retrospective analysis in Korea.

Introduction: Lentigo maligna (LM) and lentigo maligna melanoma (LMM) are rare in Asian countries. The histopathological diagnosis of LM is often challenging, and misdiagnosis is common. Although histopathologic features of LM/LMM are known, statistical analysis of them were scarcely reported. In this study, we aimed to investigate the histopathological characteristics of LM/LMM in Korean patients and identify key histopathological clues distinguishing LM from benign lentigo. Methods: We performed a retrospective study of the clinical and histopathological features of patients diagnosed with LM/LMM at our center between 2011 and 2022. We assessed the histopathological features in each case based on 16 pathological criteria according to previous literature. Pathologically confirmed cases of benign lentigo were analyzed for comparison. Results: Twenty-one patients (10 with LM and 11 with LMM) were analyzed. Several statistically significant difference existed between the features of LM and benign lentigo (N = 10), including asymmetry of overall structure (p < 0.001), cytologic atypia (p < 0.001), predominant single-cell proliferation (p < 0.001), melanocytic nests (p = 0.033), melanocytes forming rows (p = 0.003), pagetoid spread of melanocytes (p < 0.001), and hair follicle invasion by atypical melanocytes (p < 0.001). Degree of solar elastosis was more severe in group "Age ≥ 60" (p = 0.015), and group "Diameter ≥ 20 mm" (p = 0.043). Presence of elongated rete ridges were less common in the older than 60 age group (p = 0.015) and group "Diameter ≥ 20 mm." Invasion was associated with mitosis (p = 0.001, OR 49.285), multinucleated cells (p = 0.035, OR 17.769), and degree of lymphocyte infiltration (p = 0.004). Conclusion: This study investigated the clinical and histopathologic characteristics of LM and LMM in Koreans. Although histopathological diagnosis is challenging, especially in the early stages of LM, our data showed essential histopathological changes in architectural, cytological, and dermal patterns. Considering the potential aggressiveness of LM/LMM, it is essential to recognize its histopathological features and provide timely management.

Efficacy of systematic pelvic lymphadenectomy in patients with non-endometrioid endometrial cancers: a retrospective, multicenter study in Korea.

AIM: Non-endometrioid endometrial cancer is a clinically and pathologically distinct subtype of endometrial cancer. The aim of this study was to determine whether systematic pelvic lymphadenectomy improves overall survival compared to no lymphadenectomy in non-endometrioid endometrial cancer. MATERIAL AND METHODS: The authors retrospectively reviewed the medical records and pathological findings of 112 patients who underwent surgical staging for non-endometrioid endometrial cancer from 2000 to 2006 in Korea. RESULTS: Systematic pelvic lymphadenectomy was performed in 71 patients. Pelvic lymph node metastases were identified in 31% and 14.6% patients who underwent systematic pelvic lymphadenectomy and no lymphadenectomy, respectively. After adjusting for risk factors, there was no significant difference in overall survival (odds ratio = 0.69; 95% confidence interval, 0.29-1.67) between patients who did or did not undergo systematic pelvic lymphadenectomy. On multivariate analysis, patients with lymph node metastasis had higher risk of death (odds ratio = 3.11; 95% confidence interval, 0.97-10.00) than the patients with no lymph node metastasis. CONCLUSION: Although systematic pelvic lymphadenectomy did not affect overall survival in patients with the non-endometrioid subtype, it has the potential benefit of providing prognostic information and acting as a guide for further adjuvant treatment.

Is tumor size the limiting factor in a laparoscopic management for large ovarian cysts?

PURPOSE: To assess the feasibility and short-term surgical outcome of laparoscopic surgery among women with large ovarian cysts. METHODS: We retrospectively evaluated consecutive 81 patients who received laparoscopic management for ovarian cysts with diameter ≥ 10 cm and without radiologic features suggestive of malignancy, from March 2008 to September 2011. RESULTS: Laparoscopic surgery was successful in 77 (95.1 %) of the total patients. The mean (range) operative time, estimated blood loss (EBL) and hospital stay were 107.6 (55-250 min), 226.9 (10-1300 mL) and 6.1 (4-15 days), respectively. The surgical procedures performed included salpingooophorectomy (SO) (n = 44), ovarian cystectomy (OC) (n = 22), adhesiolysis (n = 1), salpingectomy (n = 2) and total laparoscopic hysterectomy (TLH) with SO (n = 8). Conversion to laparotomy occurred with four patients. One patient had postoperative bleeding and one had minor complications associated with wound oozing at the umbilical port site. Histopathological examination revealed benign tumors in 76 patients (93.8 %), borderline ovarian tumor in three patients (3.7 %) and invasive epithelial ovarian cancer in two patients (2.5 %). Clinicopathological variables according to tumor size were not statistically different. Complications did not appear in any patients during the follow-up period. CONCLUSION: With proper patient selection, laparoscopy is a feasible and safe treatment for women with large ovarian cysts and tumor size did not have effect on laparoscopic management. However, surgeons should carefully consider the potential risk of malignancy in such patients.

The comparison of clinicopathological characteristics in primary malignant mixed mullerian tumour with epithelial endometrial carcinoma.

AIMS: We performed an age-matched case-control study to compare the clinical and pathology outcomes between histologically diagnosed primary malignant mixed mullerian tumour (MMMT) of the uterus and endometrial carcinoma. METHODS: Thirty-two women were treated for primary MMMT at seven tertiary medical centres in Korea from 2000 to 2006. For each woman with MMMT, four women with endometrioid and two with non-endometrioid endometrial carcinoma were selected as age-matched controls for analysis. Medical records were retrospectively reviewed to obtain outcome data. RESULTS: The incidence of MMMT was 2.57% (32/1244). In comparison with women with endometrioid endometrial cancer, those with MMMT were characterised by large tumour size, higher incidence of adnexal involvement and lymph node metastases, leading to advanced disease stage. Despite the frequent use of adjuvant treatment, the 5-year survival rate of women with MMMT was significantly poorer than those with endometrioid endometrial cancer. However, women with MMMT were not significantly different from those with non-endometrioid endometrial cancer in terms of important pathologic variables, apart from larger tumour size. In addition, the 5-year survival rate of women MMMT was poorer than that those with non-endometrioid endometrial cancer, but the difference was not statistically significant. CONCLUSIONS: Malignant mixed mullerian tumour is characterised by a high incidence of lymph node metastases and advanced stage at diagnosis, leading to poorer overall survival than other subtypes of endometrial carcinoma. Clinical trials for MMMT are critical for improving treatment strategies.

Efficacy of para-aortic lymphadenectomy in early-stage endometrioid uterine corpus cancer.

PURPOSE: The objective of this study was to assess whether para-aortic lymphadenectomy has therapeutic efficacy for patients with early-stage endometrioid uterine cancer who underwent systematic pelvic lymphadenectomy. METHODS: The authors retrospectively reviewed the medical records and pathological findings of 547 patients with histologically proven FIGO stage I-II endometrioid uterine cancer, based on comprehensive surgical staging, including pelvic with or without para-aortic lymphadenectomy. RESULTS: Among 547 patients, 330 patients had systematic pelvic lymphadenectomy only, and 217 had systematic pelvic with para-aortic lymphadenectomy. There were no significant differences in histopathological factors in the high-risk group, even though deep myometrial invasion (p = 0.02) and lymphvascular space invasion (p = 0.01) were more common in patients who underwent systematic pelvic with para-aortic lymphadenectomy in all study populations. Within a median follow-up of 31 (range, 5-120) months, there was no significant difference in overall survival between the pelvic lymphadenectomy only and pelvic with para-aortic lymphadenectomy groups in all populations (p = 0.77), even in high-risk patients (p = 0.82). Upon multivariate analysis, patients with lymphvascular space invasion had significantly worse overall survival (odds ratio (OR) = 7.38; 95% confidence interval (CI) = 1.86-29.23; p = 0.004). CONCLUSIONS: Although a prospective, randomized study needs to be performed for confirmation, our data suggest that the therapeutic benefit of para-aortic lymphadenectomy is uncertain in stage I and II endometrioid uterine corpus cancer, even in patients at high-risk for recurrence.

Probing mechanobiological role of filamin A in migration and invasion of human U87 glioblastoma cells using submicron soft pillars.

Filamin A (FLNa) belongs to an actin-binding protein family in binding and cross-linking actin filaments into a three-dimensional structure. However, little attention has been given to its mechanobiological role in cancer cells. Here, we quantitatively investigated the role of FLNa by analyzing the following parameters in negative control (NC) and FLNa-knockdown (KD) U87 glioma cells using submicron pillars (900 nm diameter and 2 µm height): traction force (TF), rigidity sensing ability, cell aspect ratio, migration speed, and invasiveness. During the initial phase of cell adhesion (< 1 h), FLNa-KD cells polarized more slowly than did NC cells, which can be explained by the loss of rigidity sensing in FLNa-KD cells. The higher motility of FLNa-KD cells relative to NC cells can be explained by the high TF exerted by FLNa-KD cells when compared to NC cells, while the higher invasiveness of FLNa-KD cells relative to NC cells can be explained by a greater number of filopodia in FLNa-KD cells than in NC cells. Our results suggest that FLNa plays important roles in suppressing motility and invasiveness of U87 cells.

Enhanced Sensing Behavior of Three-Dimensional Microfluidic Paper-Based Analytical Devices (3D-µPADs) with Evaporation-Free Enclosed Channels for Point-of-Care Testing.

Despite the potential in fabrication of microfluidic paper-based analytical devices (µPADs) for point-of-care testing (POCT) kits, the development of simple, accurate, and rapid devices with higher sensitivity remains challenging. Here, we report a novel method for 3D-µPAD fabrication with enclosed channels using vat photopolymerization to avoid fluid evaporation. In detail, height of the enclosed channels was adjusted from 0.3 to 0.17 mm by varying the UV exposure time from 1 to 4 s for the top barrier, whereas the exposure time for the bottom and side barriers was fixed. As a result, sample flow in the enclosed channels of 3D-µPADs showed lesser wicking speed with very scant evaporation compared to that in the hemi channels in the 3D-µPADs. The stoppage of evaporation in the enclosed channels significantly improved the gray intensity and uniformity in the detection zone of the 3D-µPADs, resulting in as low as 0.3 mM glucose detection. Thus 3D-µPADs with enclosed channels showed enhanced sensitivity compared to the 3D-µPADs with hemi channels when dealing with a small volume sample. Our work provides a new insight into 3D-µPAD design with enclosed channels, which redefines the methodology in 3D printing.

Enhanced Luminescent Detection of Circulating Tumor Cells by a 3D Printed Immunomagnetic Concentrator.

Circulating tumor cells (CTCs) are an indicator of metastatic progression and relapse. Since non-CTC cells such as red blood cells outnumber CTCs in the blood, the separation and enrichment of CTCs is key to improving their detection sensitivity. The ATP luminescence assay can measure intracellular ATP to detect cells quickly but has not yet been used for CTC detection in the blood because extracellular ATP in the blood, derived from non-CTCs, interferes with the measurement. Herein, we report on the improvement of the ATP luminescence assay for the detection of CTCs by separating and concentrating CTCs in the blood using a 3D printed immunomagnetic concentrator (3DPIC). Because of its high-aspect-ratio structure and resistance to high flow rates, 3DPIC allows cancer cells in 10 mL to be concentrated 100 times within minutes. This enables the ATP luminescence assay to detect as low as 10 cells in blood, thereby being about 10 times more sensitive than when commercial kits are used for CTC concentration. This is the first time that the ATP luminescence assay was used for the detection of cancer cells in blood. These results demonstrate the feasibility of 3DPIC as a concentrator to improve the detection limit of the ATP luminescence assay for the detection of CTCs.