A Novel Hydrogel-Bronchial Epithelial Cell Spheroids for Toxicological Evaluation

Abstract

Respiratory diseases are the leading cause of death in the world according to reports from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO: third, chronic obstructive pulmonary disease; fourth, lower respiratory infections; and sixth, trachea, bronchus and lung cancers[1]. These astounding statistics are attributed to certain risk factors that include but are not limited to air pollution and first to third-hand smoke. In addition, marijuana, the most commonly used illicit drug in the US, is becoming legal in certain states for recreational use. However, with the increase in use, the question of long-term respiratory health effects becomes crucial. In addition, evidence has emerged that US military personnel deployed to Iraq and Afghanistan may be at risk for developing respiratory symptoms and, in some cases, disabling chronic lung diseases including chronic bronchitis, emphysema, asthma, and constrictive bronchiolitis. Because of this public health concern, there seems to have a necessity for effective respiratory toxicology in vitro models. While still valuable, two-dimensional (2D) methods are simplistic and overlook important biological parameters that influence cellular behavior. The purpose of this study is to elucidate the efficacy of bronchial epithelial cells (Beas-2B) in a novel alginate-based spheroid as a three-dimensional (3D) cytotoxicity testing model. Toxicants including gun range dust and Δ9- tetrahydrocannabinol (Δ9 THC) were used to verify if this model can be used for cytotoxicity testing. Viability of encapsulated Beas-2B cells was analyzed following exposure to gun range dust extract and Δ9- tetrahydrocannabinol THC. This study established that Beas-2B cells encapsulated in a novel alginate-chitin nanofiber hydrogel spheroid is an effective three-dimensional cytotoxicity testing model.

Chitin Nanofibrils Enabled Core–Shell Microcapsules of Alginate Hydrogel

“…Notably, the cell body in 2D looks flattened shape and abnormal polarization which can be rarely observed on the 2D surface of alginate/chitin hydrogel. The result indicates that the composite has strong biocompatibility and cell adhesive capacity, which are in agreement with our previously reported work [27]. The fluorescence microscopy images of encapsulated NIH/3T3 cells within the cultured alginate/chitin of 3D microcapsules can be observed in Figure 9.…”

“…Single microcapsule was compressed to a maximum of 30% of their original diameter for 30 s and force-displacement curves and data were recorded automatically by the software associated with Micro-Tester-G2. Young modulus values of the core-shell microcapsules were computed as described in prior publications [26,27].…”

Fabrication and Characterization of Zn Particle Incorporated Fibrous Scaffolds for Potential Application in Tissue Healing and Regeneration

“…PZ-10 and PCZ-10 show a drastic increase in the Young's modulus and UTS as the Zn particles tend to reinforce the polymeric matrix. However, as the Zn concentration increases beyond a threshold, abrupt changes in the polymeric matrix occur, presenting discontinuities and lowering UTS as seen in several other composite fibers of PCL with metallic nanoparticles, including Mg, Ca, Zn, Fe, and so forth. − …”

“…Briefly, the cell-laden fibrous scaffolds were treated with 10% AB reagent in cultured media and incubated for 4 h. Assay solutions were transferred to 96-well plates to measure fluorescence (530 nm excitation and 590 nm emission). The cell toxicity of PZ and PCZ scaffolds was evaluated using a Pierce LDH assay kit following the manufacturer’s instruction and also with reference to our previous work. , Briefly, 50 μL of collected sample media ( n = 3) was transferred to a 96-well plate and mixed with a 50 μL reaction mixture. The plate was covered with aluminum foil and incubated at room temperature for 30 min.…”

“…The cell toxicity of PZ and PCZ scaffolds was evaluated using a Pierce LDH assay kit following the manufacturer's instruction and also with reference to our previous work. 43,44 Briefly, 50 μL of collected sample media (n = 3) was transferred to a 96-well plate and mixed with a 50 μL reaction mixture. The plate was covered with aluminum foil and incubated at room temperature for 30 min.…”