Anthocyanin stability studies in Tibouchina semidecandra L.

The effects of pH, storage period, temperature, light and dark conditions on the stability of anthocyanins extracted from Tibouchina semidecandra flowers of different developmental stages was evaluated. Fully formed but unopened flower bud had the highest amount of total anthocyanin extracted from fresh petals. The anthocyanin contents for all flower developmental stages were stable at pH 0.5–3.0 but the colour of the extracts faded at higher pH values. Degradation percentages of total anthocyanins in the extracts kept at 25 °C were 7–20% lower than that maintained at 31 °C. Extracts stored in darkness at 25 °C maintained their purple colour for 26 days while light exposure reduced it to an average of 10 days. The study shows that suitable storage condition for coloured anthocyanin pigments in extracted form is in acidic conditions in the dark. This implies the potential usage of coloured anthocyanins as natural food colourants and shelf life indicator for acidic foods

Transforming growth factor beta 3 induced human adipose-derived stem cells for auricular chondrogenesis

The limitation of self-repair and proliferation capacity of chondrocytes in cartilage reconstruction lead to alternative search of cell source that can improve the auricular regeneration. Human adipose-derived stem cells (HADSC) are an alternative cell source that have unique characteristics to self-renew and differentiate into various tissues making it suitable for cell therapy and tissue engineering. This study aimed to examine the chondrogenic differentiation potential of (HADSC) in monolayer culture by the presence of different transforming growth factor beta’s, TFG-β1, -β2 and -β3. HADSC at passage 3 (1.5 × 105 cell/mL) were cultured in chondrogenic medium containing 5 ng/mL of different transforming growth factor beta’s, TFG-β1, -β2 and -β3 for 7, 14 and 21 days. Data analysis was evaluated based on the growth rate of cells, cells morphological changed, production of collagen type II and glycosaminoglycan sulphate (sGAG). The quantitative RT-PCR was carried out to determine the chondrogenic, fibrogenic and hypertrophic gene expression levels. Differentiation of HADSC into chondrocytes using TFG-β indicates the occurrence of the chondrogenesis process. The best chondrogenic differentiation was observed in HADSC induced by TFG-β3 through the chondrocytes-like cells morphology with cells aggregation and high production of proteoglycan matrices compared to other TGF-βs groups. Additionally, the expression of chondrocytes-specific genes such as Type II collagen, Aggrecan core protein, Elastin and Sox 9 was high. In conclusion, this study has showed that TGF-β3 is the potential growth factor in producing chondrogenic cells for auricular cartilage tissue engineering

Effects of Flower and Fruit Extracts of Melastoma malabathricum Linn. on Growth of Pathogenic Bacteria: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium

Melastoma malabathricum Linn. is a shrub that comes with beautiful pink or purple flowers and has berries-like fruits rich in anthocyanins. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against Listeria monocytogenes IMR L55, Staphylococcus aureus IMR S244, Escherichia coli IMR E30, and Salmonella typhimurium IMR S100 using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). In addition, the growth of Listeria monocytogenes IMR L55 and Staphylococcus aureus IMR S244 grown in medium supplemented with the respective extracts at different temperatures (4°C, 25°C, and 37°C) and pHs (4, 6, 7, and 8) was determined

Shelf-life evaluation of bilayered human skin equivalent, MyDerm™.

Skin plays an important role in defense against infection and other harmful biological agents. Due to its fragile structure, skin can be easily damaged by heat, chemicals, traumatic injuries and diseases. An autologous bilayered human skin equivalent, MyDerm™, was engineered to provide a living skin substitute to treat critical skin loss. However, one of the disadvantages of living skin substitute is its short shelf-life, hence limiting its distribution worldwide. The aim of this study was to evaluate the shelf-life of MyDerm™ through assessment of cell morphology, cell viability, population doubling time and functional gene expression levels before transplantation. Skin samples were digested with 0.6% Collagenase Type I followed by epithelial cells dissociation with TrypLE Select. Dermal fibroblasts and keratinocytes were culture-expanded to obtain sufficient cells for MyDerm™ construction. MyDerm™ was constructed with plasma-fibrin as temporary biomaterial and evaluated at 0, 24, 48 and 72 hours after storage at 4°C for its shelf-life determination. The morphology of skin cells derived from MyDerm™ remained unchanged across storage times. Cells harvested from MyDerm™ after storage appeared in good viability (90.5%±2.7% to 94.9%±1.6%) and had short population doubling time (58.4±8.7 to 76.9±19 hours). The modest drop in cell viability and increased in population doubling time at longer storage duration did not demonstrate a significant difference. Gene expression for CK10, CK14 and COL III were also comparable between different storage times. In conclusion, MyDerm™ can be stored in basal medium at 4°C for at least 72 hours before transplantation without compromising its functionality

Population doubling time (PDT) of cells at different periods of MyDerm™ storage time after 144 hours culture.

<p>Population doubling time (PDT) of cells at different periods of MyDerm™ storage time after 144 hours culture.</p

MyDerm™ (9.6 cm² construct) before being processed for analysis.

<p>MyDerm™ (9.6 cm² construct) before being processed for analysis.</p