The Effect of Sericin from Various Extraction Methods on Cell Viability and Collagen Production

Silk sericin (SS) can accelerate cell proliferation and attachment; however, SS can be extracted by various methods, which result in SS exhibiting different physical and biological properties. We found that SS produced from various extraction methods has different molecular weights, zeta potential, particle size and amino acid content. The MTT assay indicated that SS from all extraction methods had no toxicity to mouse fibroblast cells at concentrations up to 40 μg/mL after 24 h incubation, but SS obtained from some extraction methods can be toxic at higher concentrations. Heat-degraded SS was the least toxic to cells and activated the highest collagen production, while urea-extracted SS showed the lowest cell viability and collagen production. SS from urea extraction was severely harmful to cells at concentrations higher than 100 μg/mL. SS from all extraction methods could still promote collagen production in a concentration-dependent manner, even at high concentrations that are toxic to cells

Tissue engineering: from basic sciences to clinical perspectives

[Excerpt] Tissue engineering and regenerative medicine are interre-lated terms and go hand in hand whether we discuss aboutcells (of any kind especially stem and progenitor cells), bio-materials as matrices (2D films, 3D forms of scaffolds,nanofibers, hydrogels, nanoparticles, aerogel, microcapsules,mats, biogel for 3D printing, blends of naturals and/or syn-thetics, and others), and addition of bioactive molecules(delivery of growth hormones and drugs) for improvementand/or regeneration of tissues for biomedical applications (inrelation to cartilage, shin, bone, blood vessels, nerve conduits,cardiac, adipose, tissue expression, and others). Therefore,it includes basic principles of biological sciences, materialchemistry, and relevant engineering subjects. Finally formedical applications after proper clinical verifications of theappropriate films, scaffolds, devices, delivery systems, andother relevant products are needed. [...

Enhancing Effect of Glycerol on the Tensile Properties of Bombyx mori Cocoon Sericin Films

An environmental physical method described herein was developed to improve the tensile properties of Bombyx mori cocoon sericin films, by using the plasticizer of glycerol, which has a nontoxic effect compared with other chemical crosslinkers. The changes in the tensile characteristics and the structure of glycerolated (0–40 wt% of glycerol) sericin films were investigated. Sericin films, both in dry and wet states, showed enhanced tensile properties, which might be regulated by the addition of different concentrations of glycerol. The introduction of glycerol results in the higher amorphous structure in sericin films as evidenced by analysis of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra, thermogravimetry (TGA) and differential scanning calorimetry (DSC) curves. Scanning Electron Microscopy (SEM) observation revealed that glycerol was homogeneously blended with sericin molecules when its content was 10 wt%, while a small amount of redundant glycerol emerged on the surface of sericin films when its content was increased to 20 wt% or higher. Our results suggest that the introduction of glycerol is a novel nontoxic strategy which can improve the mechanical features of sericin-based materials and subsequently promote the feasibility of its application in tissue engineering

The potential of chitosan-tripolyphosphate microparticles in the visualisation of latent fingermarks

Chitosan (CS) is a cationic polymer with excellent film, gel and particle-forming properties. This polymer has been investigated widely for its potential in the development of food and drug delivery systems and pharmaceutical applications, however it has not generally been considered in forensic applications for example fingerprints (fingermarks). Fingerprints are a very common form of physical evidence. The most commonly used procedure for revealing the ridge pattern is powder dusting, which relies on the mechanical adherence of fingerprint formulation to the fatty components of the skin deposit that are secreted by sweat pores that exist on friction ridges. Cross-linking between oppositely charged molecules can be used to prepare chitosan microparticles. Tripolyphosphate (TPP) is a nontoxic polyanion; it can form particles by ionic interaction between positively charged amino groups of CS and negatively charged counter ions of TPP. In the present study chitosan microparticles (CSMPs) were prepared under four different processing/formulation conditions. The development of latent fingermarks using CSMPs was analysed by using a 23 factorial design, which considered simultaneously three main factors: pH, ionic strength and CS: TPP (v/v) ratio. In this study CS: TPP ratio has the strongest effect on fingerprint quality. The best conditions for fingerprint visualisation were pH 4.8, CS: TPP of 2:1 and 0.2 M of ionic strength in buffer (AB-12)

Sericin Ameliorates the Properties of Poly(Vinyl Alcohol) Hydrogel Prepared by Simple Repeated Freeze-Thaw Process without the Use of Chemical Crosslinking

Hydrogel of polyvinyl alcohol (PVA) and sericin can be easily produced using a repeated freeze-thaw process. The effects of polymer concentration (4-8 %wt), blending ratio of PVA/sericin (100/0-50/50), and the number of freeze-thawing cycle (4, 8, and 12 cycles) on chemical and physical properties of the hydrogels obtained were studied. We here showed that higher polymer concentration, higher PVA ratio, and more cycles of freeze-thawing produced the hydrogels with high gel (crosslinked) fraction (>90), wall-like structure, and high compressive modulus (100-170 kPa). When the sericin ratio was increased, the hydrogels showed less gel fraction (60-80), more porous structure with highly interconnected pores, and better swelling ability (up to 8-9 times of its original state). The formation of the PVA/sericin hydrogels was occurred by the conformational changes of both PVA and sericin. The secondary structures of PVA and sericin turned to more stable crystalline conformation during the freeze-thawing process, as confirmed by fourier transform infrared (FTIR) spectroscopic results. Furthermore, all hydrogels were not toxic to human skin keratinocytes (HaCaT) cells while the anti-oxidant activity of sericin component in hydrogels was confirmed. We concluded that the freeze-thawing process was a simple and effective technique for fabrication of PVA and sericin, which both are water-soluble, into the stable hydrogels without the use of any chemical solvents or further crosslinking. More importantly, sericin enhances the biological activities of the hydrogels, allowing the use of this hydrogel in various medical applications such as wound dressing

STABILITY OF ANTHOCYANIN IN MULBERRY FRUITS EXTRACT ADSORBED ON CALCIUM ALGINATE BEADS

Abstract Anthocyanins from water extracts of the mulberry fruits (Morus alba L./Jul cultivars) were adsorbed on calcium alginate beads. The beads were produced by external gelation using different concentrations of alginate solution. The calcium alginate beads were studied on capability of water, mulberry extract adsorption and anthocyanin stability at high temperature. The adsorption ability of the bead was found to be depended on the pH of the aqueous media. Mulberry extracts (pH4.3) had the highest adsorption at 1684.30±154.80 %(wt/wt). Beads (1.5%Alginate, ALG) average size were at 415.63±13.09 µm. Water (pH6.8) adsorption of the same type of beads was at 242.68±2.59 %(wt/wt) (325.00±17.09 µm). Anthocyanin encapsulation efficiency was at 17.08±0.25 mg/g Dry weight. Stability of adsorbed anthocyanin on calcium alginate bead was studied. After heat exposure at 40 o C and 100 o C for 10 hrs, anthocyanin was at 92%wt and 24%wt, respectively. Calcium alginate beads enhanced anthocyanin stability in the beads at these conditions by 10-40%. These results provided the useful data for process and storage condition of mulberry products

Periostin staining within renal tissues from IgA nephropathy patients

Periostin is a novel biomarker related to kidney disease progression. The aim of this study was to examine the level of periostin staining within renal tissue from IgA nephropathy patients. Immunohistochemistry for periostin was performed. The score of periostin staining and the correlation of periostin staining score with each pathological feature were evaluated. Positive periostin staining was found in renal tissue from IgA nephropathy patients including glomerular, interstitial, vascular and tubular areas. Tubular epithelial cell staining, tubular cell cast staining and periglomerular staining were common histologic features positive for periostin. Periglomerular staining were correlated with interstitial fibrosis as well as with tubular epithelial cell staining. In addition, tubular cell cast staining were correlated with tubular epithelial cell staining as well as with tubular atrophy staining. We concluded that periostin may be a promising biomarker in IgA nephropathy patients

A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED CROSSOVER STUDY OF CAPPRA® FOR THE TREATMENT OF MILD OR MILD TO MODERATE ERECTILE DYSFUNCTION IN THAI MALE male

Erectile dysfunction (ED) is one of the major health concerns affects the quality of life among Thai male. The treatment of ED by the first-line drugs is limited to a certain group of patients due to their side effects and costs. Alternative medicine can be beneficial for the treatment of ED. This is a randomized, double-blind, placebo-controlled, crossover study aimed to assess the efficacy and safety of Cappra®, a traditional herbal medicine which was used in Thailand for decades, for the treatment of mild and mild to moderate ED in Thai patients. A total of 63 patients with mild or mild to moderate ED were randomized to receive Cappra® or placebo for two weeks in the first period, followed by one week washout period. The patients were switched to the alternative treatment in the second period. The efficacy was assessed by the International Index of Erectile Function (IIEF) questionnaire and adverse events. Sixty one patients completed the study. There was an improvement of IIEF score for all domains in Cappra® group compared with placebo group. The mean change of IIEF score from baseline for erectile function domain of Cappra® was significantly higher than placebo (4.87 vs 3.44, p = 0.032). The most common adverse events were dizziness (13.3% Cappra®, 9.6% placebo), face numbness (1.6% Cappra®, 0% placebo), and tachycardia (1.6% Cappra®, 0% placebo). The results from this study demonstrated that Cappra® is effective and well-tolerated and can be used as alternative therapy for mild and mild to moderate ED