Selective Targeting and Restrictive Damage for Nonspecific Cells by Pulsed Laser-Activated Hyaluronan-Gold Nanoparticles.

Herein, we describe an approach that immobilizes low-molecular-weight hyaluronic acid (low-MW HA) on the surface of gold nanoparticles (GNPs), which can serve as a cellular probe and photodamage media, to evaluate the selectivity and efficiency of HA-based GNPs (HGNPs) as a mediator of laser-induced photothermal cell damage. In addition, it is known that solid tumors contain a higher content of low-MW HA than normal tissues. Thus, we used low-MW HA rather than high-MW HA used in other studies. In the present study, we conjugated low-MW HA, which is a linear polysaccharide with a disaccharide repeat unit, to prevent a reduction of the ligand-receptor binding efficiency in contrast to the conjugation of protein or peptides, which have unique three-dimensional structures. Three cell lines-MDA-MB-435 S (with CD44), MDA-MB-453 and NIH/3T3 (both are without CD44)-were investigated in the study, and qualitative observations were conducted by dark-field microscopy and laser scanning confocal microscopy (LSCM). In addition, quantitative measurements calculated using inductively coupled plasma emissions were taken for comparison. Our results showed that within the same treatment time, the uptake dosage of HGNPs by the MDA-MB-435 S cells was higher than that by the MDA-MB-453 and NIH 3T3 cells. Meanwhile, HGNPs uptake by the untreated MDA-MB-435 S cells was higher than that of MDA-MB-435 S cells with CD44 blocked by antibodies or silencing CD44 expression. This result implies that receptor-mediated endocytosis can enhance the cellular uptake of HGNPs. In addition, when exposed to a low-power pulsed laser, the former cell morphologies showed a more laser-induced giant plasma membrane vesicles (GPMV) than the latter morphologies. Therefore, this study utilized the specific photothermal property of HA-modified GNPs with laser-induced blebs to create a possible new method for medical applications.

Disturbed eating tendency and related factors in grade four to six elementary school students in Taiwan.

OBJECTIVE: This study investigated Taiwanese elementary school students' status in terms of body size, body satisfaction and disturbed eating tendencies. METHODS: In a cross-sectional survey, 1,261 elementary school children from grades four to six participated in this study. We used an anonymous selfreported questionnaire, which included: demographics and body satisfaction; Children's Eating Attitude Test -26 (ChEAT-26); Nowicki-Strickland Locus of Control Scale; and Influence of Significant Others Scale and Media Impact Scale. RESULTS: We found that 58.4% of the children were of normal weight, and 32.7% of the boys and 22.2% of the girls were over-weight or obese. Moreover, 39% of the children wanted to be thinner. The mean ChEAT-26 score was 8.71±8.35, and 10.5% of the children were at high risk for disturbed eating tendencies (ChEAT-26≥20), including 8.4% of the boys and 12.6% of the girls. Scores on the ChEAT-26, Nowicki-Strickland Locus of Control Scale, Influence of Significant Others Scale and Media Impact Scale were positively correlated. The level of external control and the influence of significant others and the media were significantly higher in children with disturbed eating attitudes than in those without them. Multivariable logistic regressions showed that disturbed eating attitudes were associated with body satisfaction, locus of control, and the level of influence of significant others and the media. CONCLUSIONS: Disturbed eating behaviors exist among elementary school students in Taiwan. This survey highlights the need for education in acquiring healthy mental attitudes and eating behaviors by elementary school students.

Hyaluronan-cisplatin conjugate nanoparticles embedded in Eudragit S100-coated pectin/alginate microbeads for colon drug delivery.

Hyaluronan-cisplatin conjugate nanoparticles (HCNPs) were chosen as colon-targeting drug-delivery carriers due to the observation that a variety of malignant tumors overexpress hyaluronan receptors. HCNPs were prepared by mixing cisplatin with a hyaluronan solution, followed by dialysis to remove trace elements. The cells treated with HCNPs showed significantly lower viability than those treated with cisplatin alone. HCNPs were entrapped in Eudragit S100-coated pectinate/alginate microbeads (PAMs) by using an electrospray method and a polyelectrolyte multilayer-coating technique in aqueous solution. The release profile of HCNPs from Eudragit S100-coated HCNP-PAMs was pH-dependent. The percentage of 24-hour drug release was approximately 25.1% and 39.7% in pH 1.2 and pH 4.5 media, respectively. However, the percentage of drug released quickly rose to 75.6% at pH 7.4. Moreover, the result of an in vivo nephrotoxicity study demonstrated that Eudragit S100-coated HCNP-PAMs treatment could mitigate the nephrotoxicity that resulted from cisplatin. From these results, it can be concluded that Eudragit S100-coated HCNP-PAMs are promising carriers for colon-specific drug delivery.