Combination of cytoplasmic and nuclear patterns on Hep-2 antinuclear antibody is useful as a screening test for anti-synthetase syndrome.

OBJECTIVE: This study aimed to establish a screening model for differentiating anti-synthetase syndrome (ASS) from other ANA-associated rheumatic diseases (AARDs) using a combination of cytoplasmic and non-cytoplasmic ANA (ncANA) patterns. METHODS: : This retrospective observational study included patients with AARDs such as SLE, SSc, SS, MCTD and PM/DM who underwent ANA screening between April 2012 and December 2021. Variables included age, sex, ANA patterns (Cytoplasmic and ncANA) and titres. Logistic regression analysis of Cytoplasmic and ncANA patterns was performed to differentiate ASS from other AARDs. RESULT: : The 981 diagnosed cases of AARDs consisted of SS (n = 451), SSc (n = 264), SLE (n = 201), PM/DM (n = 104), MCTD (n = 52) and ASS, including PM/DM (n = 64). Of these, 155 patients had ≥2 overlapping diseases; however, there was no overlap between AARDs and ASS. ASS is more likely to occur when the cytoplasmic titre is positive and the ncANA <320. Receiver operating characteristic analysis of the Cytoplasmic and ncANA range revealed an area under the receiver operating characteristic curve of 0.885 (95% CI: 0.844-0.927). CONCLUSION: : It is important to detect cytoplasmic patterns as an ANA screening test for ASS diagnosis, even if the titre is low. Additionally, combining the cytoplasmic and ncANA patterns yields more accurate ASS screening results.

Incidence and potential risk factors of human cytomegalovirus infection in patients with severe and critical coronavirus disease 2019.

BACKGROUND: Human cytomegalovirus (HCMV) infection occurs in immunosuppressed individuals and is known to increase mortality. Patients with coronavirus disease 2019 (COVID-19) are often treated with steroids, require intensive care unit (ICU) treatment, and may therefore be at risk for HCMV infection. However, which factors predispose severely ill patients with COVID-19 to HCMV infection and the prognostic value of such infections remain largely unexplored. This study aimed to examine the incidence and potential risk factors of HCMV infection in patients with severe or critical COVID-19 and evaluate the relationship between HCMV infection and mortality. METHODS AND FINDINGS: We used administrative claims data from advanced treatment hospitals in Japan to identify and analyze patients with severe or critical COVID-19. We explored potential risk factors for HCMV infection using multivariable regression models and its contribution to mortality in patients with COVID-19. Overall, 33,151 patients who progressed to severe or critical COVID-19 illness were identified. The incidence of HCMV infection was 0.3-1.7 % depending on the definition of HCMV infection. Steroids, immunosuppressants, ICU admission, and blood transfusion were strongly associated with HCMV infection. Furthermore, HCMV infection was associated with patient mortality independent of the observed risk factors for death. CONCLUSIONS: HCMV infection is a notable complication in patients with severe or critical COVID-19 who are admitted to the ICU or receive steroids, immunosuppressants, and blood transfusion and can significantly increase mortality risk.

Incidence and risk factors for coronavirus disease 2019-associated pulmonary aspergillosis using administrative claims data.

BACKGROUND: Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is one of the noticeable complications of COVID-19 and its incidence varies widely. In Japan, research on the incidence, risk factors and mortality associated with CAPA is limited. OBJECTIVES: This study aimed to explore the incidence and potential risk factors for CAPA in patients with severe or critical COVID-19 and evaluate the relationship between CAPA and mortality of patients with severe or critical COVID-19. METHODS: We investigated the incidence of CAPA in patients with severe and critical COVID-19 using administrative claims data from acute care hospitals in Japan. We employed multivariable regression models to explore potential risk factors for CAPA and their contribution to mortality in patients with severe and critical COVID-19. RESULTS: The incidence of CAPA was 0.4%-2.7% in 33,136 patients with severe to critical COVID-19. Age, male sex, chronic lung disease, steroids, immunosuppressants, intensive care unit admission, blood transfusion and dialysis were potential risk factors for CAPA in patients with severe to critical COVID-19. CAPA was an independent factor associated with mortality. CONCLUSIONS: CAPA is a serious complication in patients with severe and critical COVID-19 and may increase mortality.

Renin-angiotensin-aldosterone system inhibitors are associated with improved paclitaxel-induced peripheral neuropathy in lung cancer: a study using administrative claims data.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) has been reported to reduce patients' quality of life and impair cancer treatment by causing anticancer drug withdrawal or interruption. However, there are currently no effective methods for the prevention of CIPN. Renin-angiotensin-aldosterone system (RAAS) inhibitors may be associated with a reduced risk of developing oxaliplatin-induced peripheral neuropathy, and it would be valuable to examine whether they have the same effect on CIPN caused by other anticancer drugs. Our study explored the potential preventive effects of RAAS inhibitors on preventing paclitaxel-induced peripheral neuropathy (PIPN). METHODS: An exploratory cohort study was conducted using commercially available administrative claims data on lung cancer patients treated with paclitaxel-based chemotherapy. Cumulative paclitaxel doses, RAAS inhibitor prescriptions, and incidences of PIPN were identified using patient medical records. Fine-Gray analyses with death as a competing risk were performed. A propensity score approach was applied to address the problem of confounding. RESULTS: Patients with lung cancer who received paclitaxel-based chemotherapy were classified into users of RAAS inhibitor (n = 1320) and non-users of RAAS inhibitor (n = 4566). The doses of RAAS inhibitors in our study were similar to those commonly used to treat hypertension. The PIPN incidence was significantly lower in users of RAAS inhibitor than in the non-users of RAAS inhibitor (sub-distribution hazard ratio, 0.842; 95% confidence interval, 0.762-0.929). The result was consistent in various sensitivity analyses and important subgroup analyses. CONCLUSIONS: RAAS inhibitors at doses commonly used for hypertension were associated with a reduced incidence of PIPN in patients with lung cancer.

Extracellular acidification augments sclerostin and osteoprotegerin production by Ocy454 mouse osteocytes.

Osteocytes sense the microenvironmental stimuli, including mechanical stress, and regulate bone resorption by osteoclasts and bone formation by osteoblasts. Diabetes and cancer metastasis to bone raise l-lactic acid in the bone tissue, causing acidification. Here, we investigated the effects of l-lactic acid and extracellular acidification on the function of mouse Ocy454 osteocytes. L- and d-lactic acid with low chiral selectivity and acidification of the medium raised the production of sclerostin and osteoprotegerin by Ocy454 cells. The mRNA expression of their genes increased after either treatment of L- and d-lactic acid or acidification of the medium. Furthermore, the conditioned medium of Ocy454 cells cultured in an acidic environment suppressed the induction of alkaline phosphatase activity in MC3T3-E1 cells, which was recovered by the anti-sclerostin antibody. While it is reported that HDAC5 inhibits the transcription of the sclerostin gene, extracellular acidification reduced the nuclear localization of HDAC5 in Ocy454 cells. While calmodulin kinase II (CaMKII) is known to phosphorylate and induce extranuclear translocation of HDAC5, KN-62, an inhibitor of CaMKII lowered the expression of the sclerostin gene in Ocy454 cells. Collectively, extracellular acidification is a microenvironmental factor that modulates osteocyte functions.

Neural crest-derived cells in nasal conchae of adult mice contribute to bone regeneration.

Neural crest-derived cells (NCDCs), a class of adult stem cells not restricted to embryonic tissues, are attractive tissue regenerative therapy candidates because of their ease of isolation, self-renewing properties, and multipotency. Although adult NCDCs can undergo osteogenic differentiation in vitro, whether they induce bone formation in vivo remains unclear. Previously, our group reported findings showing high amounts of NCDCs scattered throughout nasal concha tissues of adult mice. In the present study, NCDCs in nasal conchae labeled with enhanced green fluorescent protein (EGFP) were collected from adult P0-Cre/CAG-CAT-EGFP double transgenic mice, then cultured in serum-free medium to increase the number. Subsequently, NCDCs were harvested and suspended in type I atelocollagen gel, then an atelocollagen sponge was used as a scaffold for the cell suspension. Atelocollagen scaffolds with NCDCs were placed on bone defects created in a mouse calvarial bone defect model. Over the ensuing 12 weeks, micro-CT and histological analysis findings showed that mice with scaffolds containing NCDCs had slightly greater bone formation as compared to those with a scaffold alone. Furthermore, Raman spectroscopy revealed spectral properties of bone in mice that received scaffolds with NCDCs similar to those of native calvarial bone. Bone regeneration is important not only for gaining bone mass but also chemical properties. These results are the first to show the validity of biomolecule-free adult nasal concha-derived NCDCs for bone regeneration, including the chemical properties of regenerated bone tissue.

A bioassay system of autologous human endothelial, smooth muscle cells, and leukocytes for use in drug discovery, phenotyping, and tissue engineering.

Blood vessels are comprised of endothelial and smooth muscle cells. Obtaining both types of cells from vessels of living donors is not possible without invasive surgery. To address this, we have devised a strategy whereby human endothelial and smooth muscle cells derived from blood progenitors from the same donor could be cultured with autologous leukocytes to generate a same donor "vessel in a dish" bioassay. Autologous sets of blood outgrowth endothelial cells (BOECs), smooth muscle cells (BO-SMCs), and leukocytes were obtained from four donors. Cells were treated in monoculture and cumulative coculture conditions. The endothelial specific mediator endothelin-1 along with interleukin (IL)-6, IL-8, tumor necrosis factor α, and interferon gamma-induced protein 10 were measured under control culture conditions and after stimulation with cytokines. Cocultures remained viable throughout. The profile of individual mediators released from cells was consistent with what we know of endothelial and smooth muscle cells cultured from blood vessels. For the first time, we report a proof of concept study where autologous blood outgrowth "vascular" cells and leukocytes were studied alone and in coculture. This novel bioassay has usefulness in vascular biology research, patient phenotyping, drug testing, and tissue engineering.

Implicit rule on the elastic function of a swollen polyacrylamide hydrogel.

A full understanding of the elastic properties of hydrogels under swelling is required for their practical application in the chemical and biomedical engineering fields. This is because hydrogels are expected to retain water during mechanical use in moist atmospheres. In the present study, we investigated the relationship between the elastic modulus and the swelling ratio in a specific type of hydrogel (a polyacrylamide gel). The elasticity and swelling data revealed that these two parameters are proportionally related in hydrogels comprising adequate amounts of monomers and crosslinkers. We also demonstrated that this proportional relationship inherently conforms to the linear elastic behaviour predicted by the Flory-Rehner free energy function (the F-R model). The implicit rule is established by the extended F-R model with two scaling exponents. The extended model is capable of representing the irregular elasticity of swollen gels formed from low- or high-molecular-weight polymers.

Characterization of taste sensitivities to amino acids and sugars by conditioned taste aversion learning in chickens.

Taste plays an essential role in regulating the feeding behaviors of animals. The present study aimed to characterize the taste sensory profiles of amino acids and sugars in chickens. To achieve this, we employed a conditioned taste aversion learning method, which is characterized by a specific pairing of gastrointestinal malaise and taste perception. Our findings revealed that chickens were able to learn to avoid L-Val, L-Lys, and L-His through conditioned taste aversion learning, and exhibited a strong aversion to L-Arg. These results suggest that chickens are primarily sensitive to basic amino acids, including L-Lys, which is a crucial limiting amino acid in feeds. Interstingly, this sensitivity to basic amino acids in chickens contrasts with humans, who are mainly sensitive to acidic amino acids as umami taste. Furthermore, despite the absence of a mammalian sweet taste receptor gene in the chicken genome, we demonstrated that chickens learned to avoid glucose, galactose, sucrose, and maltose by conditioned taste aversion learning. Taken together, the present study provides the idea that chickens possess a gustatory perception toward specific amino acids and sugars for the detection of beneficial nutrients in their feeds.

Pre-cooling for Reducing Pain from Local Anesthetic Injections for Hemorrhoidectomy: An Open-label, Randomized, Crossover Trial.

Objectives: Excisional hemorrhoidectomy (EH) is sometimes same-day surgery under local anesthesia (LA); however, the LA injection can be painful. We conducted an open-label, crossover, randomised controlled trial to evaluate the efficacy and safety of pre-cooling in reducing pain associated with LA injection. Methods: Patients aged ≥ 20 years undergoing bilateral EH were randomly assigned to 1 of 2 pre-cooling sequences: a cooling-first sequence and a cooling-second sequence. In the first intervention phase, 2 minutes of pre-cooling was applied before LA injection in patients randomized to the cooling-first sequence; patients in the cooling-second sequence were asked to wait for 2 minutes (without pre-cooling) before LA injection. The pre-cooling sequences and the perianal sides targeted for injection were reversed in the second intervention phase. The primary outcome was the visual analogue scale (VAS) rating for pain from LA injection, which was obtained twice for each patient. Adverse events due to pre-cooling (e.g., skin disorders) were documented. Results: Of 114 screened patients, 51 were randomized to the cooling-first (n = 26; analyzed: n = 26) or cooling-second sequence (n = 25; analyzed: n = 25). The 2-minute pre-cooling was completed by 48 patients (94%). VAS scores for LA injection pain decreased significantly with pre-cooling compared to without (difference estimate, -1.71; 95% confidence interval, -2.12 to -1.31; p< 0.001). No adverse events were reported. Conclusions: Two minutes of skin pre-cooling effectively and safely reduces LA injection pain in patients undergoing EH.

Immunotherapy and Overall Survival Among Patients With Advanced Non-Small Cell Lung Cancer and Obesity.

IMPORTANCE: The association between obesity and response to cancer treatment and survival remains unclear, with conflicting findings from various studies. The optimal choice between conventional chemotherapy and immunotherapy for first-line treatment remains uncertain in patients with obesity who potentially have an inadequate therapeutic response to immunotherapy. OBJECTIVE: To investigate whether body mass index (BMI) modifies the association of immunotherapy or conventional therapy with overall survival in patients with advanced non-small cell lung cancer (aNSCLC). DESIGN, SETTING, and PARTICIPANTS: A retrospective cohort study, using administrative claims data obtained from advanced treatment centers in Japan, was conducted between December 1, 2015, and January 31, 2023. Participants included individuals aged 18 years or older with aNSCLC who received immunotherapy, using immune checkpoint inhibitor (ICI) treatment or conventional chemotherapy. EXPOSURE: Immune checkpoint inhibitor therapy as first-line chemotherapy was compared with conventional chemotherapy, identified through patient medical records. MAIN OUTCOMES AND MEASURES: The main outcome was overall survival. Survival analysis covered a 3-year follow-up period after the first-line chemotherapy. RESULTS: A total of 31 257 patients with aNSCLC were identified. Of these, 12 816 patients received ICI therapy (mean [SD] age, 70.2 [9.1] years; 10 287 [80.3%] men) and 18 441 patients received conventional chemotherapy (mean [SD] age, 70.2 [8.9] years; 14 139 [76.7%] men). Among patients with BMI less than 28, ICI therapy was associated with a significantly lower hazard of mortality (eg, BMI 24: hazard ratio [HR], 0.81; 95% CI, 0.75-0.87) compared with those who underwent conventional chemotherapy. However, no such association was observed among patients with BMI 28 or greater (eg, BMI 28: HR, 0.90; 95% CI, 0.81-1.00). CONCLUSIONS AND RELEVANCE: The findings of this retrospective cohort study suggest that BMI modifies the association of ICI therapy compared with conventional chemotherapy with overall survival in patients with aNSCLC. A lack of association between ICI therapy and improved survival in patients with aNSCLC and overweight or obesity compared with conventional chemotherapy was observed. This suggests that ICI therapy may not be the optimal first-line therapy for patients with overweight or obesity and the use of conventional chemotherapy should also be considered in such patients.

Neurological prognosis prediction upon arrival at the hospital after out-of-hospital cardiac arrest: R-EDByUS score.

AIM: To develop a new scoring model for patients with cardiogenic out-of-hospital cardiac arrest (OHCA) to facilitate neurological prognosis prediction upon hospital arrival by using prehospital resuscitation features alone. METHODS: Between 2005 and 2019, we enrolled 942,891 adult patients with OHCA of presumed cardiac aetiology from the All-Japan Utstein Registry. Scoring models applied prehospital resuscitation features a priori from the variables the American College of Cardiology algorithm including age, duration to return of spontaneous circulation (ROSC) or hospital arrival, no bystander cardiopulmonary resuscitation (CPR), unwitnessed arrest, and nonshockable rhythm (R-EDByUS score) to predict unfavorable neurological outcomes defined as Cerebral Performance Category 3, 4, or 5 at 1 month. We created nomograms as a "Regression-based model," and created a "Simplified model" in which points were assigned by category for predicting unfavorable neurological outcomes for both the prehospital ROSC cohort (67,064 patients) and the ongoing CPR cohort (875,827 patients). For internal validation, bootstrap optimism-corrected estimates of predictive performance were calculated. RESULTS: A total of 46,971 (70.0%) and 870,991 (99.4%) patients in the prehospital ROSC and ongoing CPR cohorts, respectively, had unfavorable neurological outcomes. In the prehospital ROSC cohort, the C-statistics of the Regression-based and Simplified models were 0.851 and 0.842, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. In the ongoing CPR cohort, the C-statistics of the Regression-based and Simplified models were 0.872 and 0.865, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. CONCLUSIONS: The R-EDByUS score accurately predicted the neurological prognosis of cardiogenic OHCA upon hospital arrival.

Lactate-induced histone lactylation by p300 promotes osteoblast differentiation.

Lactate, which is synthesized as an end product by lactate dehydrogenase A (LDHA) from pyruvate during anaerobic glycolysis, has attracted attention for its energy metabolism and oxidant effects. A novel histone modification-mediated gene regulation mechanism termed lactylation by lactate was recently discovered. The present study examined the involvement of histone lactylation in undifferentiated cells that underwent differentiation into osteoblasts. C2C12 cells cultured in medium with a high glucose content (4500 mg/L) showed increases in marker genes (Runx2, Sp7, Tnap) indicating BMP-2-induced osteoblast differentiation and ALP staining activity, as well as histone lactylation as compared to those cultured in medium with a low glucose content (900 mg/L). Furthermore, C2C12 cells stimulated with the LDH inhibitor oxamate had reduced levels of BMP-2-induced osteoblast differentiation and histone lactylation, while addition of lactate to C2C12 cells cultured in low glucose medium resulted in partial restoration of osteoblast differentiation and histone lactylation. These results indicate that lactate synthesized by LDHA during glucose metabolism is important for osteoblast differentiation of C2C12 cells induced by BMP-2. Additionally, silencing of p300, a possible modifier of histone lactylation, also inhibited osteoblast differentiation and reduced histone lactylation. Together, these findings suggest a role of histone lactylation in promotion of undifferentiated cells to undergo differentiation into osteoblasts.

Cathepsin K degrades osteoprotegerin to promote osteoclastogenesis in vitro.

Osteoblasts produce the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin, the inducer and the suppressor of osteoclast differentiation and activation. We previously proposed that the degradation of osteoprotegerin by lysine-specific gingipain of Porphyromonas gingivalis and neutrophil elastase is one of the mechanisms of bone resorption associated with infection and inflammation. In the present study, we found that cathepsin K (CTSK) also degraded osteoprotegerin in an acidic milieu and the buffer with a pH of 7.4. The 37 k fragment of osteoprotegerin produced by the reaction with CTSK was further degraded into low molecular weight fragments, including a 13 k fragment, depending on the reaction time. The N-terminal amino acid sequence of the 37 k fragment matched that of the intact osteoprotegerin, indicating that CTSK preferentially hydrolyzes the death domain-like region of osteoprotegerin, not its RANKL-binding region. The 13 k fragment of osteoprotegerin was the C-terminal 13 k portion within the RANKL-binding region of the 37 k fragment. Finally, CTSK restored RANKL-dependent osteoclast differentiation that was suppressed by the addition of osteoprotegerin. Collectively, CTSK is a possible positive regulator of osteoclastogenesis.

A cross-sectional, multicenter survey of the prevalence and risk factors for Long COVID.

Long-term sequelae of the coronavirus disease (COVID-19) constitute Long COVID. Although Long COVID has been reported globally, its risk factors and effects on quality of life (QOL) remain unclear. We conducted a cross-sectional study using questionnaires and electronic medical records of COVID-19 patients who were diagnosed or hospitalized at five facilities in Japan. Responses were obtained from 285 out of 1,150 patients. More than half of the participants reported Long COVID symptoms of varying severity 1 year after COVID-19. Common sequelae included fatigue, dyspnea, alopecia, concentration problems, memory problems, sleeplessness, and joint pain, which often significantly reduced their QOL. COVID-19 severity was strongly associated with sputum production, chest pain, dyspnea, sore throat, and diarrhea, but not with fatigue, dysgeusia, anosmia, alopecia, and sleeplessness. Fatigue, dysgeusia, anosmia, alopecia, and sleeplessness affected the QOL among participants with asymptomatic or mild COVID-19 during the acute phase. Moreover, these sequelae persisted for prolonged periods.

Correction: Oxovanadium(v)-catalyzed amination of carbon dioxide under ambient pressure for the synthesis of ureas.

[This corrects the article DOI: 10.1039/D1RA04125H.].

Oxovanadium(v)-catalyzed amination of carbon dioxide under ambient pressure for the synthesis of ureas.

Carbon dioxide is regarded as a reliable C1 building block in organic synthesis because of the nontoxic, abundant, and economical characteristics of carbon dioxide. In this manuscript, a commercially available oxovanadium(v) compound was demonstrated to serve as an efficient catalyst for the catalytic amination of carbon dioxide under ambient pressure in the synthesis of ureas. The catalytic transformation of chiral amines into the corresponding chiral ureas without loss of chirality was also performed. Furthermore, a gram-scale catalytic urea synthesis under ambient pressure was successfully achieved to validate the scalability of this catalytic activation of carbon dioxide.

Activation and Contraction of Human "Vascular" Smooth Muscle Cells Grown From Circulating Blood Progenitors.

Blood outgrowth smooth muscle cells (BO-SMCs) offer the means to study vascular cells without the requirement for surgery providing opportunities for drug discovery, tissue engineering, and personalized medicine. However, little is known about these cells which meant that their therapeutic potential remains unexplored. Our objective was to investigate for the first time the ability of BO-SMCs and vessel-derived smooth muscle cells to sense the thromboxane mimetic U46619 by measuring intracellular calcium elevation and contraction. U46619 (10-6 M) increased cytosolic calcium in BO-SMCs and vascular smooth muscle cells (VSMCs) but not in fibroblasts. Increased calcium signal peaked between 10 and 20 s after U46619 in both smooth muscle cell types. Importantly, U46619 (10-9 to 10-6 M) induced concentration-dependent contractions of both BO-SMCs and VSMCs but not in fibroblasts. In summary, we show that functional responses of BO-SMCs are in line with VSMCs providing critical evidence of their application in biomedical research.

Methemoglobinemia induced by 1,2-dichloro-4-nitrobenzene in mice with a disrupted glutathione S-transferase Mu 1 gene.

A specific substrate to Mu class glutathione S-transferase (GST), 1,2-dichloro-4-nitrobenzene (DCNB), was administered to mice with a disrupted GST Mu 1 gene (Gstm1-null mice) to investigate the in vivo role of murine Gstm1 in toxicological responses to DCNB. A single oral administration of DCNB at doses of 500 and 1000 mg/kg demonstrated a marked increase in blood methemoglobin (MetHB) in Gstm1-null mice but not in wild-type mice. Therefore, Gstm1-null mice were considered to be more predisposed to methemoglobinemia induced by a single dosing of DCNB. In contrast, 14-day repeated-dose studies of DCNB at doses up to 600 mg/kg demonstrated a marked increase in blood MetHB in both wild-type and Gstm1-null mice. However, marked increases in the blood reticulocyte count, relative spleen weight, and extramedullary hematopoiesis in the spleen were observed in Gstm1-null mice compared with wild-type mice. In addition, microarray and quantitative reverse transcription-polymerase chain reaction analyses in the spleen showed exclusive up-regulation of hematopoiesis-related genes in Gstm1-null mice. These changes were considered to be adaptive responses to methemoglobinemia and attenuated the higher predisposition to methemoglobinemia observed in Gstm1-null mice in the single-dose study. In toxicokinetics monitoring, DCNB concentrations in plasma and blood cells were higher in Gstm1-null mice than those in wild-type mice, resulting from the Gstm1 disruption. In conclusion, it is suggested that the higher exposure to DCNB due to Gstm1 disruption was reflected in methemoglobinemia in the single-dose study and in adaptive responses in the 14-day repeated-dose study.

Assembly of Microparticles to Patterned Trenches Using the Depletion Volume Effect.

In this paper, we demonstrate that 20 µm microbeads can be preferentially assembled into substrate trenches of similar width by employing a polymer (depletant) that induces the depletion volume effect (depletion attraction). In previous works, we proved that this strategy is useful to assemble mesoscale parts in a site-specific manner. Here, we show that it is also applicable to assemble functional parts, such as fluorescent particles, into trenches engraved on the surface of two- and three-dimensional template components. A convenient advantage of this strategy is that it is independent of material properties for assembling mesoscale functional components into desired patterns.