Cryopreservation Effect on Proliferative and Chondrogenic Potential of Human Chondrocytes Isolated from Superficial and Deep Cartilage

[Abstract] Objectives: To compare the proliferative and chondrogenic potential of fresh and frozen chondrocytes isolated from superficial and deep articular cartilage biopsies. Materials and Methodology: The study included 12 samples of fresh and frozen healthy human knee articular cartilage. Cell proliferation was tested at 3, 6 and 9 days. Studies of mRNA quantification, protein expression and immunofluorescence for proliferation and chondrogenic markers were performed. Results: Stimulation of fresh and frozen chondrocytes from both superficial and deep cartilage with fetal bovine serum produced an increase in the proliferative capacity compared to the non-stimulated control group. In the stimulated fresh cells group, the proliferative capacity of cells from the deep biopsy was greater than that from cells from the superficial biopsy (0.046 vs 0.028, respectively, p<0.05). There was also a significant difference between the proliferative capacity of superficial zone fresh (0.028) and frozen (0.051) chondrocytes (p<0.05). CCND1 mRNA and protein expression levels, and immunopositivity for Ki67 revealed a higher proliferative capacity for fresh articular chondrocytes from deep cartilage. Regarding the chondrogenic potential, stimulated fresh cells showed higher SOX9 and Col II expression in chondrocytes from deep than from superficial zone (p<0.05, T student test). Conclusions: The highest rate of cell proliferation and chondrogenic potential of fresh chondrocytes was found in cells obtained from deep cartilage biopsies, whereas there were no statistically significant differences in proliferative and chondrogenic capacity between biopsy origins with frozen chondrocytes. These results indicate that both origin and cryopreservation affect the proliferative and chondrogenic potential of chondrocytes.Servizo Galego de Saúde; PS07/84Instituto de Salud Carlos III; CIBER BBN CB06-01-0040Ministerio Ciencia e Innovacion; PLE2009-0144Ministerio Ciencia e Innovación; PI 08/202

Ultrafast reclamation of fracking effluents using surface-engineered nanosilicon sponges

Effluents from the fracking process are typically discharged at elevated temperatures and are a major environmental concern. We applied a surface-engineered sponge (SEnS) with thermal stability up to 220 ºC to reclaim emulsified oily wastewater at discharge temperatures between 30-100 ºC. The sponge achieved 92-96% removal efficiency within 5 minutes, where speed increased by 27% by melting waxes. The adsorbed oil from the SEnS was also recovered within 1-2 minutes by diluent wash. These performance metrics suggest that SEnS could emerge as a practical solution to achieve fracking water reclamation processes’ Net-Zero goals

Adsorptive Recovery of Crude Oil Microdroplets from Wastewater Using Surface Engineered Sponges

In the US, the oil industry produces over 15 billion barrels of wastewater contaminated with crude oil microdroplets annually. Current technologies are unable to remove these microdroplets at different pH conditions. Herein, an innovative surface engineered sponge (SenS) was designed by combining surface chemistry, surface charge, roughness, and surface energy. Under all pH conditions, the SEnS rapidly adsorbed oil microdroplets with 95-99% removal efficiency. The adsorbed oil was recovered at ambient conditions while the cleaned SEnS was reused for five times for crude oil adsorption. Due to the process efficacy, sponge reuse, and oil recovery, this adsorptive-recovery method using SEnS demonstrates great potential for the industrial recovery of oil from wastewater

Prokaryotic transport in electrohydrodynamic structures

When a high-voltage direct-current is applied to two beakers filled with water, a horizontal electrohydrodynamic (EHD) bridge forms between the two beakers. In this work we study the transport and behavior of bacterial cells added to an EHD bridge set-up. Organisms were added to one or to both beakers, and the transport of the cells through the bridge was monitored using optical and microbiological techniques. It is shown that Escherichia coli top10 (Invitrogen, Carlsbad, CA, USA) and bioluminescent E. coli YMC10 with a plasmid (pJE202) containing Vibrio fischeri genes can survive the exposure to an EHD liquid bridge set-up and the cells are drawn toward the anode due to their negative surface charge. Dielectrophoresis and hydrostatic forces are likely to be the cause for their transport in the opposite direction which was observed as well, but to a much lesser extent. Most E. coli YMC10 bacteria which passed the EHD bridge exhibited increased luminescent activity after 24 h. This can be explained by two likely mechanisms: nutrient limitation in the heavier inoculated vials and a 'survival of the strongest' mechanism