Prechondrogenic ATDC5 Cell Attachment and Differentiation on Graphene Foam; Modulation by Surface Functionalization with Fibronectin
ACS APPLIED MATERIALS & INTERFACES
Authors: Frahs, Stephanie M.; Reeck, Jonathon C.; Yocham, Katie M.; Frederiksen, Anders; Fujimoto, Kiyo; Scott, Crystal M.; Beard, Richard S., Jr.; Brown, Ravel J.; Lujan, Trevor J.; Solov'yov, Ilia A.; Estrada, David; Oxford, Julia Thom
Abstract
Graphene foam holds promise for tissue engineering applications. In this study, graphene foam was used as a three -dimension scaffold to evaluate cell attachment, cell morphology, and molecular markers of early differentiation. The aim of this study was to determine if cell attachment and elaboration of an extracellular matrix would be modulated by functionalization of graphene foam with fibronectin, an extracellular matrix protein that cells adhere well to, prior to the establishment of three-dimensional cell culture. The molecular dynamic simulation demonstrated that the fibronectin-graphene interaction was stabilized predominantly through interaction between the graphene and arginine side chains of the protein. Quasi-static and dynamic mechanical testing indicated that fibronectin functionalization of graphene altered the mechanical properties of graphene foam. The elastic strength of the scaffold increased due to fibronectin, but the viscoelastic mechanical behavior remained unchanged. An additive effect was observed in the mechanical stiffness when the graphene foam was both coated with fibronectin and cultured with cells for 28 days. Cytoskeletal organization assessed by fluorescence microscopy demonstrated a fibronectin-dependent reorganization of the actin cytoskeleton and an increase in actin stress fibers. Gene expression assessed by quantitative real-time polymerase chain reaction of 9 genes encoding cell attachment proteins (Cd44, Ctnna1, Ctnnb1, Itga3, Itga5, Itgav, Itgb1, Ncam1, Sgce), 16 genes encoding extracellular matrix proteins (Col1a1, Col2a1, Col3a1, Col5a1, Col6a1, Ecm1, Emilin1, Fn1, Hapin1, Lamb3, Postn, Sparc, Spp1, Thbs1, Thbs2, Tnc), and 9 genes encoding modulators of remodeling (Adamts1, Adamts2, Ctgf, Mmp14, Mmp2, Tgfbi, Timp1, Timp2, Timp3) indicated that graphene foam provided a microenvironment conducive to expression of genes that are important in early chondrogenesis. Functionalization of graphene foam with fibronectin modified the cellular response to graphene foam, demonstrated by decreases in relative gene expression levels. These findings illustrate the combinatorial factors of microscale materials properties and nanoscale molecular features to consider in the design of three-dimensional graphene scaffolds for tissue engineering applications.
Cell-Free Circulating Tumor DNA Mutation Profiling for Cervical Carcinoma as Diagnostic Biomarker: A 50-Gene Module to Future Directive
INDIAN JOURNAL OF GYNECOLOGIC ONCOLOGY
Authors: Govardhan, H. B.; Khaleel, I. A.; Shubha, S. A.; Manisha, R.; Nivedita, S.; Noopur, N.; Jayashree, N. P.; Fareena, T.; Sweta, K.
Abstract
PurposeAcross the globe, cervical cancer is the most common female malignancy, second only to breast cancer, as in both incidence and mortality. Currently, tissue biopsy is the gold standard to verify carcinoma of uterine cervix initial diagnosis and can be challenging due to its invasive nature. In this study, our objective was a noninvasive genetic panel for timely detection of cervical carcinoma and its progression using cell-free tumor DNA (ctDNA).MethodsTwenty-five cervical carcinoma patients were tested with a 50-gene tumor panel. ctDNA isolated from serum was checked for single-nucleotide variations (SNVs) or copy number alterations using targeted next-generation sequencing, with further validation of results by checking respective formalin-fixed paraffin-embedded tumor tissues for the same genetic alterations.ResultsOut of 50 genes, 32 were detected in the serum samples. The SNVs detected included TP53 in 52.3% patients, CDKN2A in 47.6%, PTEN and STK11 in 33.3% patients, BRAF and VHL in 28.5% patients, EGFR and SMAD4 in 19% patients; CTNNB1, GNAS, KIT, APC, PIK3CA in 14.28% patients; SMARCB1, SMO, RET, FBXW7, ERBB2, CSF1R, CDH1, AKT1, ATM, EBB4, FGFR3, FLT3, HRAS, JAK3, MET, NOTCH1, NPM1, KRAS, PTPN11 in 4.7 to 9.5% patients. On combining alterations in BRAF, CDKN2A, EGFR, PIK3CA, PTEN, STK11, TP53 and VHL genes, at least one of the genetic alterations was found in 100% patients.ConclusionThese findings illustrate that ctDNA is easily demonstrable and can be used as a surrogate for tissue biopsy in uterine cervix carcinoma.