Electrospun polycaprolactone matrices with tensile properties suitable for soft tissue engineering.

The extracellular environment is a complex network of functional and structural components that impart chemical and mechanical stimuli that affect cellular function and fate. Cell differentiation on three dimensional scaffolds is also determined by the modulus of the substrate. Electrospun PCL nanofibers, which mimic the extra cellular matrix, have been developed with a wide variety of solvents and their combinations. The various studies have revealed that the solvents used influence the physical and mechanical properties, resulting in scaffolds with Young's modulus in the range of 1.8-15.4 MPa, more suitable for engineering of hard tissue like bone. The current study describes the use of benign binary solvent-generated fibrous scaffolds with a Young's modulus of 36.05 ± 13.08 kPa, which is almost 50 times lower than that of scaffolds derived from the commonly used solvents, characterized with myoblast, which can be further explored for applications in muscle and soft tissue engineering.

Electrospun cellulose acetate phthalate nanofibrous scaffolds fabricated using novel solvent combinations biocompatible for primary chondrocytes and neurons.

Electrospun nanofibres have been shown to exhibit extracellular matrix (ECM)-like characteristics required for tissue engineering in terms of porosity, flexibility, fibre organization and strength. This study focuses on developing novel cellulose acetate phthalate (CAP) scaffolds by electrospinning for establishing 3-D chondrocyte and neuronal cultures. Five solvent combinations were employed in fabricating the fibres, namely, acetone/ethanol (9:1), dimethylformamide/tetrahydrofuran/acetone (3:3:4), tetrahydrofuran/acetone (1:1), tetrahydrofuran/ethanol (1:1) and chloroform/methanol (1:1). The electrospun fibres were characterized by scanning electron microscopy (SEM) analysis and confirmed to be within the nanometre range. Based on the morphology of the fibers from SEM results, two solvent combinations such as acetone/ethanol and dimethylformamide/tetrahydrofuran/acetone were selected for stabilization as CAP exhibits a pH dependent solubility. Fourier-Transform Infrared (FTIR) analysis revealed the hydrolysis of CAP which was overcome by EDC [1-ethyl-3-(3-dimethylaminopropyl) carbodiimide] and EDC/NHS (N-hydroxysuccinimide) cross-linking resulting in its stability (pH of 7.2) for three months. MTT [3-(4, 5-dimethylthiazol-2-yl)-1, 5-diphenyltetrazolium bromide] assay performed using L6 myoblast confirmed the biocompatibility of the scaffolds. 3-D primary chondrocyte and neuronal cultures were established on the scaffolds and maintained for a period of 10 days. H&E staining and SEM analysis showed the attachment of the chondrocytes and neurons on CAP scaffolds prepared using dimethylformamide/tetrahydrofuran/acetone and acetone/ethanol respectively.

Evaluation of telomerase expression in chronic periodontitis.

BACKGROUND: Human telomerase is a multi subunit ribonucleoprotein enzyme concerned with telomeric lengthening and homeostasis in man. This enzyme has been found to be elevated in inflammatory conditions like rheumatoid arthritis and silica injury lung. Since chronic periodontitis is also an inflammatory condition where immune cells and cytokines mediate tissue destruction, we set out to evaluate telomerase in gingival tissue samples from healthy subjects and chronic periodontitis patients by reverse transcriptase polymerase chain reaction. MATERIALS AND METHODS: Gingival biopsies were obtained from eight healthy subjects and eight chronic periodontitis patients. Reverse transcriptase polymerase chain reaction (RTPCR) was carried out to evaluate telomerase gene expression in the samples. RESULTS: None of the healthy gingival tissue samples expressed the telomerase gene while all the chronic periodontitis samples expressed it. The severe chronic periodontitis samples expressed the gene more intensely than the moderate chronic periodontitis samples. CONCLUSION: Various mechanisms have been explained to account for telomerase elevation in chronic periodontitis .This study helps us understand the role of telomerase in the pathogenesis of periodontal disease. It could be concluded that telomerase could be used as a marker to assess the severity of inflammation in chronic periodontitis.