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Preclinical studies of nanoparticles for pulmonary therapeutics are often performed on 2D cell cultures or in vitro models that do not include a mucus barrier. However, the mucus layer lining the lungs is an essential barrier for drugs to permeate in order to exert a therapeutic effect. Herein, the role of surface coating of lanthanide‐doped upconverting nanoparticles (UCNPs) and their interaction with the mucus barrier are explored using a patient‐derived 3D cell culture model. The upconverted emissions from the UCNPs are used to track them throughout the 3D model and study their localization as a function of administration time and mucus thickness. Positively charged, ligand‐free, and negatively charged, supported lipid bilayer‐coated UCNPs are evaluated. A substantial difference in the residence time in mucus and mucociliary clearance of each type of UCNP is observed in a realistic and relevant model. As such, these results underscore the need for preclinical investigations in tissue models, especially with respect to the surface properties of the nanoparticles under study. [ABSTRACT FROM AUTHOR]

Pure titanium is limited to be used in biomedical applications due to its lower mechanical strength compared to its alloy counterpart. To enhance its properties and improve medical implants feasibility, advancements in titanium processing technologies are necessary. One such technique is equal-channel angular pressing (ECAP) for its severe plastic deformation (SPD). This study aims to surface modify commercially pure titanium using micro-arc oxidation (MAO) or plasma electrolytic oxidation (PEO) technologies, and mineral solutions containing Ca and P. The composition, metallography, and shape of the changed surface were characterized using X-ray diffraction (XRD), digital optical microscopy (OM), and scanning electron microscope (SEM), respectively. A microhardness test is conducted to assess each sample's mechanical strength. The weight % of Ca and P in the coating was determined using energy dispersive spectroscopy (EDS), and the corrosion resistance was evaluated through potentiodynamic measurement. The behavior of human dental pulp cell and periodontal cell behavior was also studied through a biomedical experiment over a period of 1-, 3-, and 7-days using culture medium, and the cell death and viability can be inferred with the help of enzyme-linked immunosorbent assay (ELISA) since it can detect proteins or biomarkers secreted by cells undergoing apoptosis or necrosis. This study shows that the mechanical grain refinement method and surface modification might improve the mechanical and biomechanical properties of commercially pure (CP) titanium. According to the results of the corrosion loss measurements, 2PassMAO had the lowest corrosion rate, which is determined to be 0.495 mmpy. The electrode potentials for the 1-pass and 2-pass coated samples are 1.44 V and 1.47 V, respectively. This suggests that the coating is highly effective in reducing the corrosion rate of the metallic CP Ti sample. Changes in the grain size and the presence of a high number of grain boundaries have a significant impact on the corrosion resistance of CP Ti. For ECAPED and surface-modified titanium samples in a 3.6% NaCl electrolyte solution, electrochemical impedance spectroscopy (EIS) properties are similar to Nyquist and Bode plot fitting. In light of ISO 10993-5 guidelines for assessing in vitro cytotoxicity, this study contributes valuable insights into pulp and periodontal cell behavior, focusing specifically on material cytotoxicity, a critical factor determined by a 30% decrease in cell viability. [ABSTRACT FROM AUTHOR]

We report here the establishment and characterization of an in vitro human small airway model (SmallAir™). The epithelial cells were isolated from the distal lungs by enzymatic digestion. After amplification, the cells were seeded on the microporous membrane of Transwell inserts. Once confluent, the cultures were switched to air-liquid interface. After 3 weeks of culture, the epithelium became fully differentiated, with morphology of columnar epithelium, and a thickness of 10–15 μm. Most significantly, CC-10, a specific marker of Club cells, was highly expressed in SmallAir™. CC-10 was detected by both immune-cytochemistry and Western Blot. As expected, SmallAir™ contained few Muc5-Ac positive cells (goblet cells). In contrast, CC-10 was not detected in MucilAir™, an in vitro model of the human nasal and bronchial epithelial model. Instead, Muc5-Ac was highly expressed in MucilAir™. However, both MucilAir™ and SmallAir™ contain basal cells and ciliated cells, showing cilia beating and mucociliary clearance. Clearly, MucilAir™ and SmallAir™ are two distinct airway epithelial models. [ABSTRACT FROM AUTHOR]

Abstract: This study reports a new perfusion-based, micro three-dimensional (3-D) cell culture platform for drug testing using enabling microfluidic technologies. The features of this cell culture platform include maintaining homogenous and stable culture environments, efficient medium delivery and cells/agarose (scaffold) loading; allowing realization of more precise and high-throughput cell culture-based assays. In this work, the perfusion-based, micro 3-D cell culture platform was designed and was fabricated based on SU-8 lithography and PDMS (poly-dimethylsiloxane) replication processes. The performance of the integrated pneumatic micropumps and cells/agarose loading mechanism were experimentally evaluated. The results show that in all of the 15 pneumatic micropumps studied, the medium delivery mechanism was able to provide a uniform flow output at flow rates ranging from 3.6μl/h to 439.0μl/h, depending on the applied pulsation frequency of the micropumps. In addition, the cell/agarose (scaffold) loading mechanism was proven to be able to perform sample loading tasks precisely and accurately in all of the 15 microbioreactors investigated with adjustable loading volumes of 0.22μl, 0.18μl and 0.14μl at applied air pressures of 10psi, 12psi and 15psi, respectively, in the microvalves. Furthermore, anti-cancer drug testing was successfully demonstrated using the proposed culture platform and fluorescent microscopic observation. As a whole, because of miniaturization, not only does this perfusion 3-D cell culture platform provide a homogenous and steady cell culture environment, but it also reduces the need for human intervention. Moreover, due to the integrated pumping of the medium and the cell/agarose (scaffold) loading mechanisms, time efficient and economical research work can be achieved. These characteristics are found particularly useful for high-precision and high-throughput 3-D cell culture-based drug testing. [Copyright &y& Elsevier]

Abstract: Mechanical compression plays an important role in modulating cell physiology. To precisely investigate the cellular response to compression, a stable culture condition is required. In this study, we developed a microbioreactor platform capable of providing dynamic compressive loading to the 3-D cell culture constructs under a steady environment. The mechanism of generating compression stimulation to cells is based on the pneumatically-driven deformation of a polydimethylsiloxane (PDMS) membrane, which then exerts compressive loading to the cultured cells through a micropillar. By modulating the magnitude and frequency of the applied pneumatic pressure, the compressive loading can be generated in a tunable manner. In this study, the quantitative relationship between the applied pneumatic pressure and the generated compressive strain on the culture construct was established. Moreover, the effects of compression on the cell viability and the metabolic and biosynthetic activities of articular chondrocytes were investigated. The results disclosed that the dynamic compressive loading (51.3% strain, 1Hz) might up-regulate the metabolic activity and glycosaminoglycan biosynthesis of articular chondrocytes after 5 day culture. Overall, this study presents a micro cell culture device that is capable of exploring the effects of compressive loading on cell physiology in a precise, high-throughput, low-cost, and user-friendly manner. [Copyright &y& Elsevier]

Pigeonpea (Cajanus cajan (L.) Millsp) leaves (PL) are widely used for treating avascular necrosis of the femoral head. PL has an ideal effect on bone angiogenesis in patients with hormone-induced avascular necrosis of the femoral head and could promote the repair of blood vessels in the necrotic femoral head. Angiogenesis is beneficial to the treatment of myocardial ischemia. PL can be used to treat ischemic heart disease; however, no studies have examined whether it could protect the myocardium against ischemia injury via promoting angiogenesis. The present study aimed to investigate whether PL could encourage angiogenesis on hypoxic human umbilical vein endothelial cells (HUVECs) and whether estrogen receptor (ER-α), protein kinase B (Akt), and vascular endothelial growth factor (VEGF) (the ischemia injury salvage kinase pathway, phosphoinositide-3 kinase (PI3K)) are involved in this effect. A hypoxic HUVEC model was established by culture in the hypoxia incubator. The proliferation ability of HUVECs was determined by the 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, the migration rate of HUVECs was inspected by the Transwell method, the tube formation was evaluated by the Matrigel method, and the expression of PI3K, phosphorylated Akt (p-Akt), and VEGF was detected by Western blotting. The proliferation, migration, and tube formation were promoted by the PL extract on hypoxic HUVECs, and the hypoxia-induced downstream signaling was counteracted, leading to increased expression of PI3K, p-Akt, and VEGF in HUVECs. The current findings showed that the PL extracts encourage angiogenesis. In addition, the above effects could be mediated via ER-α and PI3K/Akt/VEGF pathways. [Display omitted] [ABSTRACT FROM AUTHOR]

OBJECTIVE: RNA interference (RNAi) refers to the phenomenon of sequence-specific degradation of homologous mRNA induced by double-stranded RNA. It has been successfully utilized to down-regulate endogenous gene expression or suppress the replication of various pathogens in mammalian cells. In this study, the effect of vector-based small interfering RNA (siRNA) promoted by pSilencer2.0-U6 inhibit hepatitis B virus (HBV) replication in cell culture was evaluated. METHODS: Three fragments of short nucleic acids, respectively, targeting on S, X and C region of HBV genome were inserted into pSilencer vectors after they were annealed with their partly antisense strands. The recombination plasmids were pS, pX and pC. These expression plasmids were transfected into HepG2-N10 cells, a cell line which stably expresses hepatitis B virus surface antigen (HBsAg), hepatitis B virus e antigen (HBeAg) and adw2 subtype Dane particles. The effect of RNAi was evaluated from the changes of DNA, RNA and protein levels. Viral antigens were measured by ELISA. Viral mRNA was analyzed by RT-PCR. The covalent closed circular DNA and genome DNA of HBV secreted into the culture media were measured by quantitative real-time PCR. Analysis of variance was performed for the results. RESULTS: Vector-based RNA interference could potently reduce HBsAg (pS vs pN: 47%, pX vs pN: 30%, and pC vs pN: 25%, P < 0.001) and HBeAg (pX vs pN: 57% and pC vs pN: 66%, P < 0.001) expression in cell culture. Furthermore, RT-PCR analysis showed that viral mRNAs were effectively degraded, thus eliminating the messengers for protein expression as well as templates for reverse transcription (pS and pC vs pN, P < 0.001; pX vs pN, P = 0.003). Quantitative real-time PCR analysis of HBV DNA revealed that vector-based RNA interference can inhibit HBV replication efficiently (pS, pX and pC vs pN, P < 0.001). CONCLUSIONS: Our results indicate that RNAi can inhibit HBV gene expression and replication, and it might have the potential to revolutionize the treatment of HBV. [ABSTRACT FROM AUTHOR]