Synergistic Effect of Polyethylene Glycol and Lactic Acid on Handling Properties and Antibacterial Efficacy of Premixed Calcium Silicate Cement.

Calcium silicate (CaSi) bone cement with antibacterial and osteogenic properties has attracted significant interest. However, there is a need to develop a variety of new premixed bone cement to meet the clinical requirements of fast setting time, ease of handling, and efficient antibacterial properties. In this study, different volume ratios of polyethylene glycol (PEG) and lactic acid liquids were added to calcium silicate, and the effects of varying liquid-to-powder ratios (L/P) were examined. This study assessed the physicochemical properties, cytotoxicity, and antibacterial activity against S. aureus and E. coli of this premixed cement. The results from the experiments indicated that lactic acid significantly reduced the setting time of the CaSi-based cement and enhanced its mechanical strength. Furthermore, the appropriate concentration of lactic acid and matching L/P ratio improved its washout resistance. The cell viability of all premixed cement was found to be over 80%. The premixed cement containing PEG and lactic acid exhibited superior antibacterial properties compared to the CaSi control. Based on its setting time, washout resistance, and antibacterial activity, a premixed cement with a liquid phase of 80% PEG and 20% lactic acid at an L/P ratio of 0.4 appeared promising for use in dental and orthopedic practice.

Development of a Nucleic Acid Lateral Flow Immunoassay for the Detection of Human Polyomavirus BK.

The BK virus (BKV) is an emerging pathogen in immunocompromised individuals and widespread in the human population. Polymerase chain reaction is a simple and highly sensitive method for detecting BKV, but it is time consuming and requires expensive instruments and expert judgment. The lateral flow assay, a rapid, low-cost, minimal-labor, and easy-to-use diagnostic method, was successfully applied for pathogen detection. In this study, we used oligonucleotide probes to develop a simple and rapid sandwich-type lateral flow immunoassay for detecting BKV DNA within 45 minutes. The detection limit for the synthetic single-stranded DNA was 5 nM. The specificity study showed no cross-reactivity with other polyomaviruses, such as JC virus and simian virus 40. For the Escherichia coli containing BKV plasmid cultured samples, the sensitivity was determined to be 107 copies/mL. The approach offers great potential for BKV detection of various target analytes in point-of-care settings.

Do cuttlefish have fraction number sense?

Number sense is a key cognitive function in animals. The biological functions of number discrimination have a wide range, including the selection of prey and social interaction. In a previous study, we have shown that cuttlefish are able to distinguish numerical differences among various integers, including 1 vs. 2, 2 vs. 3, 3 vs. 4, and 4 vs. 5. However, it is not known whether cuttlefish are able to discriminate various fractions, that is, various non-integer numbers. In addition, no study on invertebrates has examined fraction number sense. Using the active preying behavior of cuttlefish (Sepia pharaonis), we investigated the spontaneous preference for larger quantity by presenting two-alternative choice between 1 vs. 1.5, 1.5 vs. 2, 2 vs. 2.5, and 2.5 vs. 3. In this context, the quantity1.5 is composed of one large shrimp and one small shrimp, in which the size of the small shrimp is one-half of that of the large shrimp. The result shows that the cuttlefish chose larger quantity in the first three pairs, but they could not distinguish the pair 2.5 vs. 3. Despite that the absolute differences in these pairs are the same (0.5), the relative differences in these pairs decrease (0.5, 0.33, 0.25, and 0.2, respectively). This implies that the perceived difference in quantity is proportional to the initial quantity (Weber's law). Although the present study does not truly differentiate the number difference from the quantity difference, this result does raise the possibility that cuttlefish may be equipped with the primitive concept of fractions, and if so, the perceived just noticeable difference is similar for both integer and fraction number discrimination.

Combination of resveratrol-containing collagen with adipose stem cells for craniofacial tissue-engineering applications.

Repair and regeneration of craniofacial tissues is particularly challenging because they comprise a complex structure of hard and soft tissues involved in intricate functions. This study combined collagen scaffolds and human adipose stem cells (hASCs) for oral mucosal and calvarial bone regeneration by using resveratrol (RSV), which affects the differentiation of mesenchymal stem cells. We have evaluated the effect of collagen scaffold-containing RSV (collagen/RSV) scaffolds both in vitro and in vivo for their wound healing and bone regeneration potential. Scanning electron microscopy and immunostaining results reveal that hASCs adhere well to and proliferate on both collagen scaffolds and collagen/RSV scaffolds. Oral mucosal lesion experiments demonstrated that the collagen/RSV scaffold is more effective in wound closure and contraction than the collagen scaffold. The micro-computed tomography (µCT) images of calvarial bone display regenerating bone in defects covered with hASCs on collagen/RSV scaffolds that are more visible than that in defects covered with hASCs on a collagen scaffolds. RSV was more effective at inducing hASC differentiation on the collagen scaffold, suggesting that collagen/RSV scaffolds can provide useful biological cues that stimulate craniofacial tissue formation.

Evaluating the effectiveness of a novel atomized liquid needle-free transdermal delivery system.

Needle-free jet injections constitute a crucial method for drug delivery. A novel liquid drug delivery system has been proposed recently, in which pressure atomizes liquid before delivering that atomized liquid to the patient's body; however, the mechanism and efficiency of the system are unclear. This study explored the shot delivery pressure, penetration depth, and cumulative amount of permeation of this system. This system was used to deliver 0.5% (w/v) methylene blue to agarose phantoms at various shot delivery pressures. Shots of methylene blue were also delivered to porcine skin samples at different shot delivery frequencies for light microscopy evaluation. A commercial microneedle array was used for comparing the effectiveness of the skin penetration depths. The array was gently stamped against porcine skin; methylene blue was subsequently applied to the area for different time points, followed by microscopic observations. In vitro skin penetration was tested using static Franz diffusion cells over 8 h. Finally, the feasibility of the system's clinical application was evaluated by analyzing the local analgesic effect in a heat nociceptive animal model. The penetration depths created using 100 shots at 100 psi were similar to those created using the commercial microneedle array for 2 h. Thermal stimulation responses showed that 15 min after diclofenac sodium was delivered by the system, heat nociception was significantly attenuated for 60 min. Our study presents a novel delivery system that may be useful for future clinical applications.

Amelioration of ethanol-induced liver injury in rats by nanogold flakes.

The purpose of this study was to investigate the protective effects of nanogold flakes against alcoholic liver disease. Six-week-old male Wistar rats were divided into 6 groups: C (control liquid diet), CLF (control liquid diet with gold flakes at 1.03 mg/kg body weight [BW]/day), CHF (control liquid diet with gold flakes at 5.15 mg/kg BW/day), E (ethanol liquid diet), ELF (ethanol liquid diet with gold flakes at 1.03 mg/kg BW/day), and EHF (ethanol liquid diet with gold flakes at 5.15 mg/kg BW/day). The liquid diets were prepared daily. Gold flakes were added to the ethanol 1 h before preparing the ethanol liquid diets, as an aging process. After 10 weeks, rats in group E showed significantly higher plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities than those in group C. A significantly increased concentration of hepatic triglyceride (TG) was found in group E. Furthermore, higher hepatic glutathione reductase (GRD), superoxide dismutase (SOD), and catalase (CAT) activities together with higher tumor necrosis factor (TNF)-α concentration and higher hepatic cytochrome (CYP2E1) protein expression were also observed in group E. In contrast, the hepatic TG concentration in group EHF was significantly lower than that of group E. In addition, hepatic glutathione peroxidase (GPX), SOD, and CAT activities together with TNF-α concentration and hepatic CYP2E1 protein expression in group EHF were significantly lower than those in group E. We concluded that nanogold flakes might ameliorate alcohol-induced liver injury by maintaining the hepatic antioxidative status. In addition, nanogold flakes may reduce fat accumulation caused by chronic ethanol feeding via decreasing hepatic TNF-α.

Identification of the nanogold particle-induced endoplasmic reticulum stress by omic techniques and systems biology analysis.

Growth inhibition and apoptotic/necrotic phenotype was observed in nanogold particle (AuNP)-treated human chronic myelogenous leukemia cells. To elucidate the underlying cellular mechanisms, proteomic techniques including two-dimensional electrophoresis/mass spectrometry and protein microarrays were utilized to study the differentially expressed proteome and phosphoproteome, respectively. Systems biology analysis of the proteomic data revealed that unfolded protein-associated endoplasmic reticulum (ER) stress response was the predominant event. Concomitant with transcriptomic analysis using mRNA expression, microarrays show ER stress response in the AuNP-treated cells. The ER stress protein markers' expression assay unveiled AuNPs as an efficient cellular ER stress elicitor. Upon ER stress, cellular responses, including reactive oxygen species increase, mitochondrial cytochrome c release, and mitochondria damage, chronologically occurred in the AuNP-treated cells. Conclusively, this study demonstrates that AuNPs cause cell death through induction of unmanageable ER stress.

The treatment of bladder cancer in a mouse model by epigallocatechin-3-gallate-gold nanoparticles.

(--)-Epigallocatechin-3-gallate (EGCG), an active ingredient in green tea, was known to effectively inhibit formation and development of tumors. However, excessive uptake of EGCG was also known to cause cytotoxicity to normal cells. In this study, EGCGs that were physically attached onto the surface of nanogold particles (pNG) was confirmed by scanning electron microscopy. The anticancer activity of the EGCG-adsorbed pNG was investigated in C3H/HeN mice subcutaneously implanted with MBT-2 murine bladder tumor cells. EGCG-pNG was confirmed to inhibit tumor cell growing by means of cell apoptosis. The mechanism that EGCG-pNG mediates tumor apoptosis was uncovered to activate the caspase cascade through the Bcl-family proteins in the mitochondrial pathway. Additionally, the mechanism that tumors were suppressed by injecting EGCG-pNG directly into the tumor site was determined to be through downregulation of VEGF, whereas that by oral administration of EGCG was through reversing immune suppression upon cancer progression. In this assessment, the prepared EGCG-pNG was confirmed to be more effective than free EGCG in inhibiting bladder tumor in model mice.