Assessment of Angiogenesis and Cell Survivability of an Inkjet Bioprinted Biological Implant in an Animal Model.

The rapidly growing field of tissue engineering hopes to soon address the shortage of transplantable tissues, allowing for precise control and fabrication that could be made for each specific patient. The protocols currently in place to print large-scale tissues have yet to address the main challenge of nutritional deficiencies in the central areas of the engineered tissue, causing necrosis deep within and rendering it ineffective. Bioprinted microvasculature has been proposed to encourage angiogenesis and facilitate the mobility of oxygen and nutrients throughout the engineered tissue. An implant made via an inkjet printing process containing human microvascular endothelial cells was placed in both B17-SCID and NSG-SGM3 animal models to determine the rate of angiogenesis and degree of cell survival. The implantable tissues were made using a combination of alginate and gelatin type B; all implants were printed via previously published procedures using a modified HP inkjet printer. Histopathological results show a dramatic increase in the average microvasculature formation for mice that received the printed constructs within the implant area when compared to the manual and control implants, indicating inkjet bioprinting technology can be effectively used for vascularization of engineered tissues.

Thermal inkjet bioprinting triggers the activation of the VEGF pathway in human microvascular endothelial cells in vitro.

One biofabrication process that has gained tremendous momentum in the field of tissue engineering and regenerative medicine is cell-printing or most commonly bioprinting. We have shown that thermal inkjet bioprinted human microvascular endothelial cells were recruited or otherwise involved in the formation of microvasculature to form graft-host anastomoses upon implantation. The present study aims to quantify and characterize the expression and activation of specific cytokines and kinases in vitro. Morphological characteristics demonstrate elongated protrusions of TIB-HMVECs at 5-6 times the size of manually pipetted cells. Moreover, annexin V-FITC and propidium iodide apoptosis assay via flow cytometry demonstrated a 75% apoptosis among printed cells as compared to among control cells. Cell viability at a 3 d incubation period was significantly higher for printed cells as compared to control. Milliplex magnetic bead panels confirmed significant overexpression of HSP70, IL-1α, VEGF-A, IL-8, and FGF-1 of printed cells compared to control. In addition, a Human phospho-kinase array displayed a significant over activation of the heat-shock proteins HSP27 and HSP60 of printed cells compared to the manually seeded cells. Collectively, it is suggested that the massive appearance of capillary blood vessels upon implantation that has been reported elsewhere may be due to the activation of the HSP-NF-κB pathway to produce VEGF. This cell activation may be used as a new strategy for vascularization of tissue engineered constructs which are in high demand in regenerative medicine applications.

Sexual attitudes, norms, condom use, and adherence of Hispanic and non-Hispanic undergraduate students: a cross-sectional study of three community colleges in southwestern US.

OBJECTIVE: To measure the sexual attitudes, norms, condom use, and adherence of Hispanic and non-Hispanic undergraduate students in three community colleges in the southwestern US. METHODS: A previously validated instrument was used in this study (sexual risk behavior beliefs and self-efficacy survey). Statistical analyses included chi-square and one-way analysis of variance with post hoc multiple comparisons using the Statistical Program for the Social Sciences. RESULTS: The study participants included 234 first and second year community college students. Nearly 91% of them were sexually active and 95% reported healthy sexual attitudes. However, only 29% reported adhering to consistent condom use. More females believed that condoms should always be used, even if the two people knew each other very well, when compared to males (P=0.04). Hispanic female participants were less confident they could abstain from sex when compared to non-Hispanics (P=0.00). Non-Hispanic females were more confident they could use or explain to their partner how to use a condom correctly and go to the store to buy condoms than their Hispanic female (P=0.01) and male counterparts (P=0.00). CONCLUSION: Our study findings indicate that adherence to consistent condom use was low among Hispanic college students. This may help explain why they are more likely to report unwanted pregnancies and sexually transmitted infections. There is a documented need to introduce culturally sensitive health promotion programming specifically designed to meet the needs of this at-risk and understudied population.

The impact of the 2002 Delaware smoking ordinance on heart attack and asthma.

In the United States, smoking is the leading cause of death - having a mortality rate of approximately 435,000 people in 2000-accounting for 8.1% of all US deaths recorded that year. Consequently, we analyzed the Delaware Hospital Discharge Database, and identified state and non-state residents discharged with AMI or asthma for the years 1999 to 2004. Statistical data analysis compared the incidence of AMI or asthma for each group before (1999-2002) and after (2003-2004) the amendment. As a result, we found that pre-ordinance and post-ordinance quarterly rates of AMI for Delaware residents were 451 (se = 21) and 430 (se = 21) respectively, representing a 4.7% reduction. Over the same time period, there was negligible change in the incidence of AMI for non-Delaware residents. After adjusting for population growth, the Risk Ratio (RR) for asthma in Delaware residents post-ordinance was 0.95 (95% CI, 0.90 to 0.999), which represented a significant reduction (P = 0.046). By comparison, non-Delaware residents had an increased RR for asthma post-ordinance of 1.62 (95% CI, 1.46 to 1.86; P < 0.0001).The results suggest that Delaware's comprehensive non-smoking ordinance effectively was associated with a statistically significant decrease in the incidence of AMI and asthma in Delaware residents when compared to non-Delaware residents.