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Hydrogels with low viscosities tend to be difficult to use in constructing tissue engineering (TE) scaffolds used to replace or restore damaged tissue, due to the length of time it takes for final gelation to take place resulting in the scaffolds collapsing due to their mechanical instability. However, recent advances in rapid prototyping have allowed for a new technology called bioplotting to be developed, which aims to circumvent these inherent problems. This paper aims to present details of the process.

The paper demonstrates how by using the bioplotting technique complex 3D geometrical scaffolds with accurate feature sizes and good pore definition can be fabriated for use as biological matrices. PEG gels containing the cell‐adhesive RGD peptide sequence were patterned using this method to produce layers of directional microchannels which have a functionalised bioactive surface. Seeding these gels with C2C12 myoblasts showed that the cells responded to the topographical features and aligned themselves along the direction of the channels.

This process allows plotting of various materials into a media bath containing material of similar rheological properties which can be used to both support the structure as it is dispensed and also to initiate cross‐linking of the hydrogel. By controlling concentrations, viscosity and the temperature of both the plotting material and the plotting media, the speed of the hydrogel gelation can be enhanced whilst it is cross‐linking in the media bath. TE scaffolds have been produced using a variety of materials including poly(ethylene glycol) (PEG), gelatin, alginic acid and agarose at various concentrations and viscosities.

This paper describes one of the very few examples of accurate construction of 3D biological microporous matrices using hydrogel material fabricated by the bioplotting technique. This demonstrates that this technique can be used to produce 3D scaffolds which promote tissue regeneration.

This paper aims to develop a novel micro-ablation system to realise micrometric and well-defined hydrogel structures. To engineer a tissue it is necessary to evaluate several aspects, such as cell-cell and cell-substrate interactions, its micro-architecture and mechanical stimuli that act on it. For this reason, it is important to fabricate a substrate which presents a microtopology similar to natural tissue and has chemical and mechanical properties able to promote cell functions. In this paper, well-defined hydrogel structures embedding cells were microfabricated using a purposely developed technique, micro-laser ablation, based on a thulium laser. Its working parameters (laser power emission, stepper motor velocity) were optimised to produce shaded “serpentine” pattern on a hydrogel film.

In this study, initially, swelling/contraction tests on agarose and alginate hydrogel in different solutions of main components of cell culture medium were performed and were compared with the MECpH model. This comparison matched with good approximation experimental measurements. Once known how hydrogel changed its topology, microstructures with a well-defined topology were realised using a purposely developed micro-laser ablation system design. S5Y5 neuroblastoma cell lines were embedded in hydrogel matrix and the whole structure was ablated with a laser microfabrication system. The cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam.

The hydrogel structure is able to reproduce extracellular matrix. Initially, the hydrogel swelling/contraction in different solutions, containing the main components of the most common cell culture media, was analysed. This analysis is important to evaluate if cell culture environment could alter microtopology of realised structures. Then, the same topology was realised on hydrogel film embedding neuronal cells and the cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam. The interesting obtained results could be useful to realise well-defined microfabricated hydrogel structures embedding cells to guide tissue formation

The originality of this paper is the design and realisation of a 3D microfabrication system able to microfabricate hydrogel matrix embedding cells without inducing cell damage. The ease of use of this system and its potential modularity render this system a novel potential device for application in tissue engineering and regenerative medicine area.

ß-thalassemia is a hereditary disorder due to mutation in the ß-globin gene on chromosome 11. Out of 200 known ß-globin gene chain mutations recognized, it is better to identify the most common mutation in specific regions and ethnicity for cost-effective molecular diagnosis of this disorder. Therefore, this study aims to practice multiplex-amplification refractory mutation system (ARMS) PCR on patients with thalassemia in Khyber Pakhtunkhwa (KP) to investigate the most common mutations in the ß-globin chain gene.

Twenty-two individuals (patients, their parents and non-affected siblings) with signed consent were studied from six consanguineous families of ß-thalassemia. Blood samples were collected for DNA isolation. For the detection of mutations in the ß-globin gene, ARMS-PCR was used. The amplicon was visualized through 2% Agarose Gel.

The most common mutations among different ethnic groups in the study area residents were Fr 8-9 (+G) and IVS 1-5 (G> C). The prominent enhancing factors for ß-thalassemia are inter-family marriages and lack of awareness.

Multiplex ARMS_PCR is the most valuable technique for assessing multiple mutations in a single reaction tube.

Due to extensively found ethnic and regional variations and a high rate of consanguinity, the Pashtun population has a great risk of mutations in their genome. Therefore, ARMS-PCR is a cost-effective mutational diagnostic strategy that can help to control disease burden.

Limited studies using ARMS-PCR for mutational analysis in the ß-globin gene are conducted. This study is unique as it targeted consanguineous families of KP Pakistan.

This paper aims to study the color change kinetics of lac dye in response to pH and food spoilage metabolites (ammonia, lactic acid and tyramine) for its potential application in intelligent food packaging.

UV-Vis spectroscopy was used to study the color change of dye solution. Ratio of absorbance of dye solution at 528 nm (peak of ionized form) to absorbance at 488 nm (peak of unionized form) was used to study the color change. Color change kinetics was studied in terms of change in absorbance ratio (A528/A488) with time using zero- and first-order reaction kinetics. An indicator was prepared by incorporating lac dye in agarose membrane to validate the result of study for monitoring quality of raw milk.

Dye was orange-red in acidic medium (pH: 2 to 5) and exhibited absorbance peak at 488 nm. It turned purple in alkaline medium (pH: 7 to10) and exhibited absorbance peak at 528 nm. The change in absorbance ratio with pH followed zero-order model. Acid dissociation constant (pKa) of dye was found to be 6.3. Color change of dye in response to ammonia and tyramine followed zero-order reaction kinetics, whereas for lactic acid, the first-order model was found best. In the validation part, the color of the indicator label changed from purple to orange-red when the milk gets spoiled.

The study opens a new application area for lac dye. The results suggest that lac dye has potential to be used as an indicator in intelligent food packaging for detection of spoilage in seafood, meat, poultry and milk.

This study aims to treat the development and application of sequence characterised amplified region (SCAR) markers for the detection of plant based adulterants (dried red beet pulp and powdered Ziziphus nummularia fruits) in traded ground chilli.

Adulterant‐specific DNA fragments (red beet pulp specific – “Beet 01” and Z. nummularia specific – “Ziz 01”) identified by random amplified polymorphic DNA polymerase chain reaction (RAPD‐PCR) analysis were cloned and sequenced for SCAR marker development. Red beet pulp specific SCAR primer pair, B1, and Z. nummularia specific SCAR primer pair, Z1, were designed from the corresponding RAPD marker sequences to amplify SCAR markers of 320 bp and 389 bp, respectively. The utility of the SCAR markers for adulterant detection was verified in model blends of chilli powder with the adulterants. Six commercial samples of ground chilli powder were analysed using the SCAR markers.

SCAR markers could detect the adulterants at a concentration as low as 10 g adulterant kg⁻¹ of blended sample. The Z. nummularia SCAR marker could detect the presence of Z. nummularia fruit adulteration in one of the commercial samples. All the market samples tested were free from red beet pulp adulteration.

The PCR‐based method developed in the study is simple, rapid, and sensitive and has the potential to be developed into a quantitative analytical method and for commercial PCR kits for the large‐scale screening of ground chilli to detect and prevent plant‐based adulterants. The work has public health significance too, as ground chilli is one of the major spices consumed worldwide.

The study is the first report on the development of SCAR markers for adulterant detection in ground chilli. This work has relevance, as adulteration is a major concern of the sanitary and phytosanitary issues of the World Trade Organization (WTO) agreement.

This study aims to monitor seawater by determing two biological indicators, Escherichia coli and Enterococcus faecalis. The process of following standard procedures is mainly time-consuming. Thus, there is a demand for a biosensor, an appropriate device for rapid and accurate results that can give information about the microbiological quality of seawater in an effective and rapid way.

In the gold standard method for seawater monitoring, the filter method is applied as a condensation step. In this work, the authors evaluated six types of common syringe filters for bacteria concentration and then the best filter was used for seawater analysis for E. coli and Enterococci with loop-mediated isothermal amplification (LAMP) polymerase chain reaction (PCR).

Cellulose acetate filter had the highest efficiency (98%) for bacterial concentration. The limit of detection of the LAMP method was 104/1,000 mL for both E. coli and E. faecalis. The proposed method could be used for the development of seawater biosensors with advantages such as a simple heating element and the speed that the LAMP PCR presents.

The suggested protocol is proposed in an integrated in situ system, a biosensor, for seawater quality determination.

The presence of Bacillus sporothermodurans in retail UHT milk along with milk from different points of a processing line was determined. This paper aims to investigate the effect of chilling, pre‐heating, UHT, reprocessing and H₂O₂ individually and in combination on the survival of B. sporothermodurans in broth.

Standard plate counts were conducted for all milk samples and isolates from UHT milk were characterised using PCR. BS vegetative cells and spores in broth were subjected to various stresses encountered, during UHT processing of milk. Survival counts were conducted after all treatments.

B. sporothermodurans was detected in retail UHT milk packs from only one processor. UHT treatment at 140°C for 4s eliminated B. sporothermodurans in broth. The combination of chilling and UHT was more effective in eliminating B. sporothermodurans spores than UHT treatment alone. H₂O₂ was also effective in eliminating B. sporothermodurans spores after 15 min of exposure. The adopted real time (RT) PCR with SYBR Green method was effective for the confirmation of B. sporothermodurans.

This research is the first to be conducted with regards to the detection of B. sporothermodurans in UHT milk in South Africa and determining the effect of UHT processing stresses on their survival. These results can be used to design processing parameters so as to effectively eliminate B. sporothermodurans spores during UHT processing. This research is the first in which RT PCR with SYBR Green has been used to characterise B. sporothermodurans.

Recently, powerful instruments for biomedical engineering research studies, including disease modeling, drug designing and nano-drug delivering, have been extremely investigated by researchers. Particularly, investigation in various microfluidics techniques and novel biomedical approaches for microfluidic-based substrate have progressed in recent years, and therefore, various cell culture platforms have been manufactured for these types of approaches. These microinstruments, known as tissue chip platforms, mimic in vivo living tissue and exhibit more physiologically similar vitro models of human tissues. Using lab-on-a-chip technologies in vitro cell culturing quickly caused in optimized systems of tissues compared to static culture. These chipsets prepare cell culture media to mimic physiological reactions and behaviors.

The authors used the application of lab chip instruments as a versatile tool for point of health-care (PHC) applications, and the authors applied a current progress in various platforms toward biochip DNA sensors as an alternative to the general bio electrochemical sensors. Basically, optical sensing is related to the intercalation between glass surfaces containing biomolecules with fluorescence and, subsequently, its reflected light that arises from the characteristics of the chemical agents. Recently, various techniques using optical fiber have progressed significantly, and researchers apply highlighted remarks and future perspectives of these kinds of platforms for PHC applications.

The authors assembled several microfluidic chips through cell culture and immune-fluorescent, as well as using microscopy measurement and image analysis for RNA sequencing. By this work, several chip assemblies were fabricated, and the application of the fluidic routing mechanism enables us to provide chip-to-chip communication with a variety of tissue-on-a-chip. By lab-on-a-chip techniques, the authors exhibited that coating the cell membrane via poly-dopamine and collagen was the best cell membrane coating due to the monolayer growth and differentiation of the cell types during the differentiation period. The authors found the artificial membrane, through coating with Collagen-A, has improved the growth of mouse podocytes cells-5 compared with the fibronectin-coated membrane.

The authors could distinguish the differences across the patient cohort when they used a collagen-coated microfluidic chip. For instance, von Willebrand factor, a blood glycoprotein that promotes hemostasis, can be identified and measured through these type-coated microfluidic chips.

An efficient protocol for the isolation of high molecular weight DNA from dry powdered samples of turmeric including market samples is described which will help in PCR based detection of adulteration in marketed turmeric powders. The method involves a modified CTAB (3 per cent) procedure with 2 M NaCl, 0.3 per cent β‐mercaptoethanol coupled with purification of DNA in 30 per cent polyethylene glycol (8000). The yield of the DNA obtained from the samples varied from 2 to 4 μg/g tissue. The DNA obtained from the five different samples were consistently amplifiable (RAPD primers).

The purpose of this paper is to evaluate the prevalence of Bacillus sporothermodurans in UHT milk brands in South Africa and to analyse the level of proteolysis in UHT milk due to the growth of B. sporothermodurans during short-term and long-term storage.

Different brands and batches of commercially available retail UHT milk packages were bought from different supermarkets, during different seasons and tested for the presence of B. sporothermodurans. Sterile UHT milk was spiked with B. sporothermodurans vegetative cells and incubated at 37°C for up to 172 hours. Total plate counts, pH, spore counts, UHT milk proteolysis and the headspace volatiles dynamics were analysed at different intervals.

The contamination of retail UHT milk packages by B. sporothermodurans was found to be prevalent. The growth of B. sporothermodurans in spiked UHT milk reached a maximum of 1.9×105 cfu/ml; however, the significant proteolytic activity in UHT milk due to B. sporothermodurans only occurred long after the exponential growth phase had been attained. Furthermore, the growth of B. sporothermodurans in UHT milk did not lead to significant changes in the headspace volatile profiles of spiked UHT milk samples. Proteolytic activity in retail UHT milk packages, contaminated with B. sporothermodurans, was significantly higher when the use-by dates were reached.

Significant proteolysis in UHT milk means the assurance of high-quality UHT milk with extended storage stability for up to 10-12 months is compromised. Proteolysis of casein may lead to rapid sedimentation in UHT milk compared to UHT milk without sedimentation.

This paper is of interest to manufacturers because it raises the awareness that UHT milk containing B. sporothermodurans may not have the same storage stability when compared those without B. sporothermodurans. The presence of B. sporothermodurans in commercial UHT milk packages may lead to international and national trade restrictions for manufacturers.