Parathyroid-on-a-chip simulating parathyroid hormone secretion in response to calcium concentration.

The parathyroid gland is an endocrine organ that plays a crucial role in regulating calcium levels in blood serum through the secretion of parathyroid hormone (PTH). Hypoparathyroidism is a chronic disease that can occur due to parathyroid defects, but due to the difficulty of creating animal models of this disease or obtaining human normal parathyroid cells, the evaluation of parathyroid functionality for drug development is limited. Although parathyroid-like cells that secrete PTH have recently been reported, their functionality may be overestimated using traditional culture methods that lack in vivo similarities, particularly vascularization. To overcome these limitations, we obtained parathyroid organoids from tonsil-derived mesenchymal stem cells (TMSCs) and fabricated a parathyroid-on-a-chip, capable of simulating PTH secretion based on calcium concentration. This chip exhibited differences in PTH secretion according to calcium concentration and secreted PTH within the range of normal serum levels. In addition, branches of organoids, which are difficult to observe in animal models, were observed in this chip. This could serve as a guideline for successful engraftment in implantation therapies in the future.

Formation Pattern Analysis of Spheroids Formed by a Droplet-Based Microfluidic System for Predicting the Aggressiveness of Tumor Cells.

Examining tumor heterogeneity is essential for selecting an appropriate anticancer treatment for an individual. This study aimed to distinguish low- and high-aggressive tumor cells by analyzing the formation patterns of spheroids. The droplet-based microfluidic system was employed for the formation of each spheroid from four different subtypes of breast tumor cells. Additionally, heterotypic spheroids with T lymphocytes and cancer-associated fibroblasts (CAFs) were produced, and distinctions between low- and high-aggressive tumor cells were explored through the analysis of formation patterns using circularity, convexity, and cell distributions. In both homotypic spheroids and heterotypic spheroids with T lymphocytes, spheroids formed from low-aggressive tumor cells exhibited high circularity and convexity. On the other hand, spheroids formed from high-aggressive tumor cells had relatively low circularity and convexity. In the case of heterotypic spheroids with CAFs, circularity and convexity did not exhibit clear differences between low- and high-aggressive tumor cells, but distinct variations were observed in cell distributions. CAFs and low-aggressive tumor cells were evenly distributed, whereas the CAFs were predominantly located in the inner layer, and high-aggressive tumor cells were primarily located in the outer layer. This finding can offer valuable insights into predicting the aggressiveness of unknown tumor cells.

Evaluation of antibody drug delivery efficiency via nebulizer in various airway models and breathing patterns.

BACKGROUND: Nebulizers are commonly used to treat respiratory diseases, which are a major cause of morbidity and mortality. While inhalation therapy with antibodies has been evaluated in preclinical studies and clinical trials for respiratory diseases, it has not yet been approved for treatment. Moreover, there is limited information regarding the delivery efficiency of therapeutic antibodies via nebulizer. METHODS: In this study, the nebulization characteristics and drug delivery efficiencies were compared when immunoglobulin G (IgG) was delivered by five nebulizers using two airway models and five breathing patterns. The study confirmed that the delivered dose and drug delivery efficiency were reduced in the child model compared to those in the adult model and in the asthma pattern compared to those in the normal breathing pattern. RESULTS: The NE-SM1 NEPLUS vibrating mesh nebulizer demonstrated the highest delivery efficiency when calculated as a percentage of the loading dose, whereas the PARI BOY SX + LC SPRINT (breath-enhanced) jet nebulizer had the highest delivery efficiency when calculated as a percentage of the emitted dose. CONCLUSION: The results suggest that the total inspiration volume, output rate, and particle size should be considered when IgG nebulization is used. We, therefore, propose a method for evaluating the efficiency of nebulizer for predicting antibody drug delivery.

Quantitative analysis of sialic acid on erythrocyte membranes using a photothermal biosensor.

The quantitative analysis of sialic acid (SA) at an erythrocyte membrane is becoming an important clinical parameter in diagnosing cancer and diabetes. In spite of such clinical importance, there are only a few, very expensive, time consuming and complicated quantifying methods established. To solve this problem, we demonstrate a novel and direct measurement technique for SA exposed to the cell membrane using a photothermal biosensing system in which the hemoglobin molecules in the erythrocyte absorb a specific wavelength of photons (532 nm) and convert it to a temperature change. For measuring the quantity of SA, we first modified the sensor surface of a micro-scaled thermometer using phenylboronic acid (PBA) containing a self-assembled monolayer (SAM) to capture the SA-expressing erythrocytes. Second, the sensor surface was thoroughly washed, and when more SA was expressed, tighter association of erythrocytes to the biosensor was expected. Thirdly, blood sample changes in temperature, heated by the 532 nm wavelength laser, were measured by the bottom layer's micron sized platinum thermometer. The temperature changes from the erythrocytes captured on the sensor surface could be estimated by the amount of SA expressed on the erythrocyte membrane. This novel SA analysis system can solve the problems raised by conventional methods such as multiple enzyme reactions and a time consuming process. We expect that this system will help provide a new tool in the quantitative analysis of SA expression level for the diagnosis of diabetes and cancers.

An integrated photo-thermal sensing system for rapid and direct diagnosis of anemia.

This article presents a thermal biosensor to diagnose the anemia without chemical treatments using temperature increase of red blood cells (RBC) when hemoglobin molecules absorb specific wavelength of photons and convert them to thermal energy. For measuring temperature change of red blood cell, the micro-scaled platinum resistance temperature detector (Pt RTD) was developed. For maintenance of constant ambient temperature, we designed and fabricated a thermostat system. The thermostat system consists of a K-type thermocouple and two electric heaters that serve to increase the system temperature, which is monitored by the thermocouple. Both heaters and the thermocouple were connected to a proportional-integral-derivative (PID) controller and enabled to maintain the temperature constant (<±0.1°C). For specific heating of red blood cell, 8.0 W/cm(2) diode pumped solid state (DPSS) continuous wave (CW) laser module was used with 532 nm wavelength. Using this system, we successfully measured the temperature variations (from 66.33±2.72°C to 74.16±2.06°C) of whole blood samples from 10 anemic patients and subsequently determined the concentration of hemoglobin (from 7.2 g/dL to 9.8 g/dL). The method proposed in this paper requires significantly less amount of whole blood sample (6 µl) compared with the conventional methods (175 µl) and allows instantaneous diagnosis (3 s) of anemia.

Direct measurement of the in vitro hemoglobin content of erythrocytes using the photo-thermal effect of the heme group.

Blood hemoglobin is an important diagnostic parameter in measuring overall health. The hemoglobin molecule and the iron it contains absorb light energy, leading to thermal changes. This paper presents a new method for determining the hemoglobin concentration of erythrocytes by measuring temperature increases of the heme group when cells are heated by a 532 nm wavelength laser. The advantages of our method are that it determines the hemoglobin content of an entire blood sample without chemical treatments and requires only a small amount of blood (less than 10 microL). A micro scaled platinum resistance temperature detector (Pt RTD) was fabricated using a microelectromechanical system (MEMS) technique that directly measures the temperature changes. The platinum RTD's resistance at 0 degrees C is 275.32 Omega. For the specific heating of erythrocytes, we used a 0.03 to 9.6 W cm(-2) power tunable diode pumped solid state (DPSS) continuous wave (CW) laser module with a wavelength of 532 nm. When heating human erythrocytes, leukocytes, plasma, and reference solutions, only the temperature of the erythrocytes significantly increased, indicating that our measurement technique can be used to determine hemoglobin concentration. The hemoglobin concentrations for the samples we used were 0.34, 0.67, 1.35, 2.7, 5.4, 8.1, 10.8, 13.5, 16.2, 18.9 and 21.6 g dL(-1). The temperatures measured for each sample were 31.17 +/- 1.98, 36.34 +/- 3.76, 42.70 +/- 4.38, 48.39 +/- 6.47, 63.73 +/- 3.34, 79.09 +/- 9.60, 84.86 +/- 1.99, 87.54 +/- 9.84, 91.90 +/- 5.27, 90.00 +/- 3.24 and 95.79 +/- 2.66 degrees C at a 9.6 W cm(-2) output power of the 532 nm laser at 23 degrees C. We also provide a theoretical analysis of the temperature increases and investigate their major heat source.