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The purpose of this paper is to study the effect of laser fluence on the post‐transfer cell viability of human colon cancer cells (HT‐29) during a typical biofabrication process, matrix‐assisted pulsed‐laser evaporation direct‐write (MAPLE DW).

The post‐transfer cell viability in MAPLE DW depends on various operation conditions such as the applied laser fluence. HT‐29 cell was selected as a model mammalian cell to investigate the effect of laser fluence on the post‐transfer cell viability. MAPLE DW‐based HT‐29 cell direct writing was implemented using an ArF excimer laser under a wide range of laser fluence. Trypan blue dye‐exclusion was used to test the post‐transfer cell viability.

It has been observed that: the HT‐29 cell viability decreases from 95 to 78 percent as the laser fluence increases from 258 to 1,482 mJ/cm²; and cell injury in this study is mainly due to the process‐induced mechanical stress during the cell droplet formation and landing processes while the effects of thermal influence and ultraviolet radiation are below the level of detection.

This paper reveals some interesting relationships between the laser fluence and the post‐transfer mammalian cell viability and injury, and the resulting knowledge of these process‐related relationships helps the wide implementation of MAPLE DW‐based biofabrication. Post‐transfer cell injury reversibility and cell proliferation capacity need to be further elucidated.

This paper will help the wide implementation of cell direct‐write technologies including MAPLE DW to fabricate biological constructs as artificial tissues/organs and bio‐sensing devices.

The shortage of donor organs and the need of various bio‐sensing devices have significantly prompted the development of various biological material‐based direct‐write technologies. Process‐induced cell injury happens during fabricating of biological constructs using different direct‐write technologies including MAPLE DW. The post‐transfer cell viability is a key index to evaluate the feasibility and efficiency of any biofabrication technique. This paper has investigated the effect of laser fluence on the post‐transfer HT‐29 cell viability and injury. The knowledge from this study will help effectively and efficiently fabricate various biological constructs for organ printing and biosensor fabrication applications.

The purpose of this article is to attempt to highlight various approaches for enhancing the viability of probiotics, with special emphasis on micro‐encapsulation.

Various techniques, such as selection of acid and bile resistant strains, use of oxygen impermeable packaging materials, two‐step fermentation, stress adaptation, inclusion of micro‐nutrient, sonication of bacteria and micro‐encapsulation, which could be employed for maintaining or enhancing probiotic viability are discussed, with special emphasis on micro‐encapsulation.

Probiotics lose their viability during gastro‐intestinal transit due to unfavorable intestinal environment. Amongst diverse techniques micro‐encapsulation could confer protection to the probiotics both in the product as well as in the gastro‐intestinal environment.

The paper shows that micro‐encapsulation of probiotics renders them stable both in the product as well as in the intestinal environment and application of encapsulated probiotics would result in a product with greater prophylactic activities.

Lactobacillus rhamnosus GG, a probiotic of human origin, known to have health beneficial effects can be exposed to osmotic stress when applied in food production as important quantities of sugars are added to the food product. The aim of this study is to assess the mode of action of non‐electrolytes stress on its viability.

Investigations were carried out on stationary phase cells treated with 0‐1.5M sugars, by means of flow cytometric method (FCM) and plate enumeration method. Osmotically induced changes of microbial carboxyfluorescein (cF)‐accumulation capacity and propidium iodide‐exclusion were monitored. The ability of the cells to extrude intracellularly accumulated cF upon glucose energization was ascertained as an additional vitality marker, in which the kinetics of dye extrusion were taken into consideration as well. Sugar analysis by HPLC was also carried out.

The results of FCM analysis revealed that with sucrose, only cells treated at 1.5M experienced membrane perturbation but there was a preservation of membrane integrity and enzymatic activity. There was no loss of viability as shown by plate counts. In contrast, the majority of trehalose‐treated cells had low extent of cF‐accumulation. For these samples a slight loss of viability was recorded on plating (logN/N_o ∼ −0.45). At 0.6M, cells had similar extrusion ability as the control cells upon glucose energization. However, 20 per cent of sucrose‐treated cells and 80 per cent of trehalose‐treated cells extruded the dye in the first 10min.

This finding pointed out the importance of trehalose to enhance the dye extrusion activity, which is regarded as an analogue of the capability of cells to extrude toxic compounds. Sugars exert different effects on the physiological and metabolic status of LGG but none caused a significant viability loss. LGG can be a choice probiotic bacterium in sugar‐rich food production e.g. candies, marmalade etc., in which exposure to high osmotic pressure is be expected.

The purpose of this study was to bring a new structural hybrid design approach to improve the mechanical and biological properties of the bone scaffolds fabricated by laser powder bed fusion, selective laser melting (SLM).

In designing the hybrid scaffolds, different unit cells were used such as dodecahedron (DCH), grid (G), octet-truss (OCT) with partially dense (PDsl) and fully dense (FDsl) surface layers. After fabrication of scaffolds on SLM machine, compression test and cell viability test were applied to observe the effect of hybrid design on mechanical and biological properties of the scaffolds.

It has been observed that designing the scaffold with partially dense or FDsl surfaces did not have a critical effect on the cell viability. On the contrary, the compression strength of scaffold increased from 56  to 100 MPa when the surface layer of the scaffold was designed as FDsl surface instead of partially dense surface. It has also been observed that the scaffold having the highest hybridity (PDsl+G+DCH+OCT) delivered the highest cell viability performance and had a compressive strength slightly higher than that of the scaffolds with single unit cell, PDsl+OCT.

This study brings a new approach to designing femur bone scaffold for fabricating with SLM. This hybrid design approach, including different unit cells in a single scaffold, covers many requirements of femur bone in terms of mechanical and biological properties.

This study aims to develop a simplified bioink preparation method that can be applied to most hydrogel bioinks used in extrusion-based techniques.

The parameters of the bioprinting process significantly affect the printability of the bioink and the viability of cells. In turn, the bioink formulation and its physicochemical properties may influence the appropriate range of printing parameters. In extrusion-based bioprinting, the rheology of the bioink affects the printing pressure, cell survival and structural integrity. Three concentrations of alginate-gelatin hydrogel were prepared and printed at three different flow rates and nozzle gauges to investigate the print parameters. Other characterizations were performed to evaluate the hydrogel structure, printability, gelation time, swelling and degradation rates of the bioink and cell viability. An experimental design was used to determine optimal parameters. The analyses included live/dead assays, rheological measurements, swelling and degradation.

The experimental design results showed that the hydrogel flow rate substantially influenced printing accuracy and pressure. The best hydrogel flow rate in this study was 10 ml/h with a nozzle gauge of 18% and 4% alginate. Three different concentrations of alginate-gelatin hydrogels were found to exhibit shear-thinning behavior during printing. After seven days, 46% of the structure in the 4% alginate-5% gelatin sample remained intact. After printing, the viability of skin fibroblast cells for the optimized sample was 91%.

This methodology offers a straightforward bioink preparation method applicable to the majority of hydrogels used in extrusion-based procedures. This can also be considered a prerequisite for cell printing.

This study aims to investigate the effect of three-dimensional (3D)- bioplotted polycaprolactone (PCL) scaffold geometry on the biological and mechanical characteristics of human adipose-derived stem cell (hASC) seeded constructs.

Four 3D-bioplotted scaffold disc designs (Ø14.5 × 2 mm) with two levels of strand–pore feature sizes and two strand laydown patterns (0°/90° or 0°/120°/240°) were evaluated for hASC viability, proliferation and construct compressive stiffness after 14 days of in vitro cell culture.

Scaffolds with the highest porosity (smaller strand–pore size in 0°/120°/240°) yielded the highest hASC proliferation and viability. Further testing of this design in a 6-mm thick configuration showed that cells were able to penetrate and proliferate throughout the scaffold thickness. The design with the lowest porosity (larger strand–pore size in 0°/90°) had the highest compression modulus after 14 days of culture, but resulted in the lowest hASC viability. The strand laydown pattern by itself did not influence the compression modulus of scaffolds. The 14-day cell culture also did not cause significant changes in compressive properties in any of the four designs.

hASC hold great potential for musculoskeletal tissue engineering applications because of their relative ease of harvest, abundance and differentiation abilities. This study reports on the effects of 3D-bioplotted scaffold geometry on mechanical and biological characteristics of hASC-seeded PCL constructs. The results provide the basis for future studies which will use this optimal scaffold design to develop constructs for hASC-based osteochondral tissue engineering applications.

This study aims to protect Lactobacillus plantarum and Enterococcus faecium encapsulated in alginate beads during stress treatments, such as high temperatures and concentrations of sodium chloride (NaCl) and sodium nitrite (NaNO₂).

Free and encapsulated probiotics were subjected to 70 and 80°C during 5, 10, 20 and 30 min. In addition, the probiotics were subjected to concentrations of 0.5, 1.0, 2.5 and 5.0 per cent NaCl and 0.5 and 1.0per cent of NaNO₂.

Free Lactobacillus plantarum was more resistant to heat than free Enterococcus faecium. Alginate-encapsulated Lactobacillus plantarum (ALP) also was more resistant to heat treatments than alginate-encapsulated Enterococcus faecium (AEF). After 30 min at 70°C, ALP showed levels about 6.9 log CFU/g while AEF presented 4.3 log CFU/g (p = 0.005). However, at 80°C, ALP maintained levels higher than 6 log CFU/g for up to 10 min, while AEF was able to maintain those levels only for approximately 5 min (p = 0.003). Encapsulation process provided adequate protection for both probiotics against NaCl. In relation to NaNO₂ concentrations, 0.5 and 1.0 per cent reduced viability of both probiotics (p = 0.014), either as free cells or as alginate-encapsulated forms.

Alginate beads containing probiotics is an interesting alternative for application in foods such as cooked meat products.

Alginate beads elaborated with milk powder, inulin and trehalose were effective to protect probiotics in stress situations similar to those can be found in the processing of foods, such as cooked meat products.

Consumer inclination towards probiotic foods has been stimulated due to well-documented evidence of health benefits of probiotic-containing products and consumer demand for natural products. It is assumed that the viability and metabolic activities of probiotics are essential for extending health benefits and for successful marketing of probiotics as a functional food. The purpose of this paper is to demonstrate that even dead or inactivated probiotic cells could extend health benefits, indicating that probiotic viability is not always necessary for exhibiting health benefits.

Attempt has been made to review the literature on the status of probiotic foods available in the world market, their impact on the gut flora and the various factors affecting their viability. Both review and research papers related to efficacy of inactivated, killed or dead probiotic cells towards health benefits have been considered. Keywords used for data search included efficacy of viable or killed, inactivated probiotic cells.

The reviewed literature indicated that inactivated, killed or dead probiotic cells also possess functional properties but live cells are more efficacious. All live probiotic cultures are not equally efficacious, and accordingly, dead or inactivated cells did not demonstrate functional properties to extend health benefits to all diseases.

Capability of non-viable microorganisms to confer health benefits may attract food manufacturers owing to certain advantages over live probiotics such as longer shelf-life, handling and transportation and reduced requirements for refrigerated storage and inclusion of non-bacterial, biologically active metabolites present in fermented milks’ fraction as dried powders to food matrixes may result in the development of new functional foods.

Globally, consumer’s inclination towards functional foods had noticed due to their greater health consciousness coupled with enhanced health-care cost. The fact that probiotics could promote a healthier gut microbiome led projection of probiotic foods as functional foods and had emerged as an important dietary strategy for improved human health. It had established that ice cream was a better carrier for probiotics than fermented milked due to greater stability of probiotics in ice cream matrix. Global demand for ice cream boomed and probiotic ice cream could have been one of the most demanded functional foods. The purpose of this paper was to review the technological aspects and factors affecting probiotic viability and to standardize methodology to produce functional probiotic ice cream.

Attempt was made to search the literature (review and researched papers) to identify diverse factors affecting the probiotic viability and major technological challenge faced during formulation of probiotic ice cream. Keywords used for data searched included dairy-based functional foods, ice cream variants, probiotic ice cream, factors affecting probiotic viability and health benefits of probiotic ice cream.

Retention of probiotic viability at a level of >10⁶ cfu/ml is a prerequisite for functional probiotic ice creams. Functional probiotic ice cream could have been produced with the modification of basic mix and modulating technological parameters during processing and freezing. Functionality can be further enhanced with the inclusion of certain nutraceutical components such as prebiotics, antioxidant, phenolic compounds and dietary fibres. Based upon reviewed literature, suggested method for the manufacture of functional probiotic ice cream involved freezing of a probiotic ice cream mix obtained by blending 10% probiotic fermented milk with 90% non-fermented plain ice cream mix for higher probiotic viability. Probiotic ice cream with functional features, comparable with traditional ice cream in terms of technological and sensory properties could be produced and can crop up as a novel functional food.

Probiotic ice cream with functional features may attract food manufacturers to cater health-conscious consumers.

The study aimed to disclose the anti-cancer activity of Pluchea indica tea leaves by evaluating the cytotoxicity on breast and cervical cancer cells, compared with non-cancer cells.

Two P. indica extracts were prepared using two solvents, namely hot water (PA) and ethanol (PE). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and clonogenic assays were applied to determine cytotoxic effect of both extracts toward cancer cells from human breast (MDA-MB-231 and MCF7) and cervix (SiHa, HeLa and C-33A) and also non-cancer Vero cells. Dichlorofluorescein diacetate (DCFDA)-staining assay was used to quantify the intracellular level of the reactive oxygen species (ROS). Correlation between the quantity of compounds present and the cytotoxicity of the extracts was analyzed by Pearson's method and a possible class of bioactive compounds was proposed based on the highest correlation coefficient (r).

Significant reduction in cell viability and proliferation capability was observed in all cancer cells after treatment with either PA or PE extract albeit PE was more effective. Lower toxicity was detected in Vero cells, indicating the selectivity and safety of extracts. The intracellular ROS level was augmented in treated cancer cells which were inversely correlated to cell viability, suggesting the cancer toxicity was likely induced by intracellular oxidative stress. As flavonoids were found abundantly in the extracts and flavonoids' content was the most related to the activity (r = 0.815), it was hypothesized that the flavonoids might play crucial roles in cancer cytotoxicity.

P. indica tea-leaf extracts can be a good source of promising anti-cancer agents with reduced side effects for breast and cervical cancer treatment.