Portable biohybrid odorant sensors using cell-laden collagen micropillars.

Biohybrid odorant sensors (BOSs) composed of biological materials and artificial detectors have recently attracted much attention due to their high degree of sensitivity and selectivity. Although portability is crucial for the practical use of BOSs on site, the currently used artificial detectors for biological signals are unportable. In this study, we propose a portable cell-based odorant sensor, which uses cell-laden collagen micropillars to compensate the low optical abilities of portable artificial detectors. The micropillars were composed of HEK293T cells expressing olfactory receptors, which emit a fluorescence signal based on the extent of odorant stimulation using a calcium fluorescent indicator. By stacking cells vertically in the micropillars, we achieved different levels of amplification of the fluorescence signals by varying the height of the micropillars. As a working demonstration of the portable BOS, we successfully detected different concentrations of odorants using an inexpensive web camera. The BOS was also able to distinguish the slight differences between an agonist and an antagonist. We believe that the portability of our BOS would facilitate its applications in point-of-care testing and on-site detection of hazardous materials.

Transdermal water-in-oil nanocarriers of nitric oxide for triggering penile erection.

Men's sexual health can have significant effects on a man's self-esteem, sexual relationship and male reproductive functions. Although commercially available drugs (e.g., VIAGRA and CIALIS) show effective treatment of erectile dysfunction (ED), patients with severe ED fail to respond to these medicines. Topical nitric-oxide (NO) delivery to penis can be a painless, alternative solution with severe ED because NO triggers erection and diffuses to the trabecular arteries and smooth muscles in the penis. We here develop water-in-oil (W/O) nanoemulsions (NEs) that contain NO and can directly spread on the penis. We optimize NE formation conditions including hydrophilic-lipophilic balance (HLB) and ratio of oil, water and surfactants. Then, by spreading NEs on penis skin of intact middle aged dogs, we verify medication effects and safety of the NEs in vivo. The water-in-oil NEs can be a promising non-invasive medication for ED patients with low response to a phosphodiesterase type 5 (PDE5) inhibitor, thus increasing quality of life in the aging society.

Formation of Highly Aligned Collagen Nanofibers by Continuous Cyclic Stretch of a Collagen Hydrogel Sheet.

A collagen sheet with highly aligned collagen fibers is fabricated by continuous cyclic stretch. The rearrangement of the collagen fibers depends on the different process parameters of the cyclic stretch, including magnitude, frequency, and period of stretch. The collagen fibers are aligned perpendicularly to the direction of the stretch. Corneal stromal cells and smooth muscle cells cultivated on the highly aligned collagen sheet show alignment along the collagen fibers without the stretch during culture. Thus, the sheet can be a suitable scaffold for use in regenerative medicine.

Comparison of the canine corneal epithelial cell sheets cultivated from limbal stem cells on canine amniotic membrane, atelocollagen gel, and temperature-responsive culture dish.

OBJECTIVE: The current study compared canine corneal epithelial cell sheets cultivated from limbal stem cells on amniotic membrane, atelocollagen gel, and temperature-responsive culture dish. PROCEDURES: We collected limbal epithelial cells from the intact eyes of beagles and cultivated the cells on denuded canine amniotic membranes, temperature-responsive cell culture labware, and collagen gel with 3T3 feeder cells. Immunofluorescence staining for Ki-67 was used to analyze the capacity of cell proliferation in the sheets. Immunofluorescence staining was also performed for the corneal epithelium-specific marker cytokeratin 3 and putative stem cell markers ABCG2 and p63. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to detect ABCG2 and p63. RESULTS: The growth rates of the cultivated cells, or the times it took them to reach confluency, were different for the three scaffolds. The cultivated sheet on the temperature-responsive dish consisted of 2-3 layers, while those on the collagen gel and on the amniotic membrane consisted of 5-8 layers. The basal layer cells grown on all three scaffolds expressed putative stem cell markers. In real-time RT-PCR analysis, the highest level of p63 was observed in the sheets grown on collagen gel. CONCLUSIONS: In this study, the cells cultured on the collagen gel demonstrated a capacity for cell proliferation, and the expressions of stem cells in the sheets suggested that collagen gel is the most suitable carrier for clinical use.

A comparison of neurosphere differentiation potential of canine bone marrow-derived mesenchymal stem cells and adipose-derived mesenchymal stem cells.

Stem cell transplantation is one of the most promising yet enigmatic treatments for spinal cord injury (SCI), a common problem in dogs. As pre-differentiated mesenchymal stem cells (MSCs) can be expanded and differentiated into neurospheres in vitro, before being transplanted back, they may prove to be more beneficial for treating SCI. Therefore, we compared the endogenous differentiation potential, including the neuronal cell differentiation, of neurospheres from canine bone marrow MSCs (cBMMSCs) with that of the adipose tissue-derived MSCs (cADMSCs). Nestin-positive neurospheres were generated from MSCs derived from the bone marrow and adipose tissue. Neuronal cells were differentiated from the neurospheres derived from both these tissues. Gene expression analysis revealed that Nestin, ßIII-tubulin, NCAM, OCT4 and SOX2 were expressed in MSCs and the corresponding neurospheres. Notably, cBMMSC-derived neuronal cells expressed higher levels of ßIII-tubulin. The mRNA expressions of NANOG, Nestin, OCT4 and SOX2 were upregulated in neurospheres derived from both. Immunofluorescence analysis detected the expression of neuronal markers, namely, ßIII-tubulin, GFAP, S100, NF200 and MAP2, in differentiated neuron-like cells. Our findings highlight that both cBMMSCs and cADMSCs could be differentiated into neurospheres and neuron-like cells, and therefore, these cells are suitable candidates for cell transplantation. Further, cADMSCs form a more suitable cell source, as larger number of cells could be harvested from cADMSC-derived neurospheres. Future studies employing in vivo transplantation models to investigate the effectiveness of MSCs for treating SCI are warranted.

Cultivation of corneal epithelial cell sheets on canine amniotic membrane.

OBJECTIVE: To develop and assess canine corneal epithelial cell sheets cultivated from limbal stem cells on amniotic membrane. PROCEDURES: Canine corneal limbal segments were obtained from six beagle dogs. Cryopreserved denuded amniotic membranes (obtained from Miniature Dachshund and Cavalier King Charles Spaniel breeds) from which the epithelial cells were removed were used as scaffolds. The limbal segments were cultured on these amniotic membranes with 3T3 feeder cells for 2 weeks. The harvested corneal epithelial cell sheets were stained with H&E for histologic analysis. The harvested sheets were analyzed immunohistochemically using a corneal epithelium-specific marker keratin 3(K3) and putative stem cell markers ABCG2, p63, and vimentin. RESULTS: Cultivated cells from the corneal limbal tissues reached confluency in 7-8 days. The cultivated cells adhered to the denuded amniotic membrane and formed a sheet. The cultivated cell sheet was transparent and consisted of five to eight layers. K3 was observed in all layers and ABCG2, p63, and vimentin were notably present in the basal layer of the cultivated canine epithelium by immunofluorescence. CONCLUSIONS: Canine corneal epithelial cells were successfully cultivated on the canine amniotic membrane. The cultivated epithelial sheets contained putative stem cells in the basal layer and had a stratified epithelium.