Solvent-cast 3D printing with molecular weight polymer blends to decouple effects of scaffold architecture and mechanical properties on mesenchymal stromal cell fate.

The biochemical and physical properties of a scaffold can be tailored to elicit specific cellular responses. However, it is challenging to decouple their individual effects on cell-material interactions. Here, we solvent-cast 3D printed different ratios of high and low molecular weight (MW) poly(caprolactone) (PCL) to fabricate scaffolds with significantly different stiffnesses without affecting other properties. Ink viscosity was used to match processing conditions between inks and generate scaffolds with the same surface chemistry, crystallinity, filament diameter, and architecture. Increasing the ratio of low MW PCL resulted in a significant decrease in modulus. Scaffold modulus did not affect human mesenchymal stromal cell (hMSC) differentiation under osteogenic conditions. However, hMSC response was significantly affected by scaffold stiffness in chondrogenic media. Low stiffness promoted more stable chondrogenesis whereas high stiffness drove hMSC progression toward hypertrophy. These data illustrate how this versatile platform can be used to independently modify biochemical and physical cues in a single scaffold to synergistically enhance desired cellular response.

Substance abuse treatment utilization, HIV risk behaviors, and recruitment among suburban injection drug users in Long Island, New York.

Prevention and treatment of injection drug use remains a public health concern. We used data from the 2005 Centers for Disease Control and prevention National HIV Behavioral Surveillance system to assess substance abuse treatment utilization, risk behaviors, and recruitment processes in a respondent driven sample of suburban injectors. Twelve service utilization and injection risk variables were analyzed using latent class analysis. Three latent classes were identified: low use, low risk; low use, high risk; and high use, moderate/high risk. In multivariate analysis, annual income <$15,000 (adjusted odds ratio (aOR) = 8.19 [95 % confidence interval (CI), 3.83-17.51]) and self-reported hepatitis C virus infection (aOR = 4.32, 95 % CI (1.84-10.17)) were significantly associated with class membership. Homophily, a measure of preferential recruitment showed that injectors with recent treatment utilization appear a more cohesive group than out-of-treatment injectors. Preferentially reaching injection drug users with high risk behaviors and no recent drug treatment history via respondent driven sampling will require future research.

Changes in stress, substance use and medication beliefs are associated with changes in adherence to HIV antiretroviral therapy.

Stress, substance use and medication beliefs are among the most frequently cited barriers to HIV treatment adherence. This study used longitudinal techniques to examine the temporal relationship between these barriers and adherence among clients attending treatment adherence support programs in New York State. A total of 4,155 interview pairs were analyzed across three interview transitions. Multinomial models were constructed with four-category change-based independent variables (e.g., low stress at both interviews, low stress at interview 1 and high stress at interview 2, high stress at interview 1 and low stress at interview 2, high stress at both interviews) that predicted a similarly constructed four-category adherence change variable. Clients who reported positive changes in stress, substance use, or medication beliefs were more likely to change from being nonadherent to being adherent, while clients who reported negative changes were more likely to change from being adherent to being nonadherent. To improve or maintain adherence over time, strategies should be used that facilitate positive changes-and prevent negative changes-in stress, substance use, and medication beliefs.

Adherence to HAART: perspectives from clients in treatment support programs.

The development of highly active antiretroviral therapy (HAART) has resulted in dramatic decreases in morbidity and mortality for HIV-infected individuals. Because the long-term efficacy of HAART is dependent on near perfect adherence, many providers offer services to support adherence, including education, regimen review, counseling, and reminder tools. Little is known regarding the utilization or efficacy of these services. In this paper, we report on data collected during 32 open-ended interviews conducted with individuals receiving services through the New York State Treatment Adherence Demonstration Project. Participants in the project reported deriving benefits from a broad range of project activities. Educational efforts helped clients to recognize HIV as a manageable, rather than terminal, illness. Information and tools focused on specific regimens provided clients with concrete knowledge and skills. Effective communication with medical providers and pharmacists was facilitated by adherence staff who proactively advocated for client needs. Program-based social support was particularly valuable for many participants, helping them to retain needed motivation and strength. Educational, practical, and supportive services were all considered valuable to clients participating in adherence support programs. A mix of services may best meet the range of needs found among persons taking HAART.

Correlation of a brief perceived stress measure with nonadherence to antiretroviral therapy over time.

Adherence to antiretroviral medications has proven to be a challenge for individuals diagnosed with HIV infection. Nonadherence can lead to treatment failure, HIV resistance, and poor health outcomes. Many published studies have described factors associated with poor adherence, yet few have presented validated scales that could practically be applied in treatment settings to identify individuals at higher risk of nonadherence. This article explores the relationship between a revised version of the Perceived Stress Scale and nonadherence to antiretroviral therapy. The scale consists of the following items: How often in the past month have you felt that you were unable to control the important things in your life; confident in your ability to handle your personal problems; that things were going your way; and difficulties were piling up so high you could not handle them? Response options were "never or rarely," "sometimes," "often," and "mostly or always." In multivariate analysis, clients who scored in the highest quartile of perceived stress were more than twice as likely to be nonadherent at baseline and follow-up 1 and more than 5 times as likely to be nonadherent at follow-up 2 than clients in the lowest quartile of perceived stress scores.

Stability of adherence to highly active antiretroviral therapy over time among clients enrolled in the treatment adherence demonstration project.

Adherence to antiretroviral medications is essential to therapeutic success. Many published studies have investigated the degree of adherence or nonadherence, but sample sizes have generally been small, and adherence has seldom been viewed as a longitudinal process. This paper investigates the stability of adherence over time among HIV-infected individuals attending adherence support programs in New York State. The study cohort consists of 435 clients who were on HAART at baseline and who completed at least 2 follow-up interviews. Although cross-sectional nonadherence did not exceed 35%, nonadherence reached 54% when considered across all 3 interviews. Analysis of transition matricies revealed moderate stability in adherence over time (e.g., first follow-up adherence was 81.0% for clients adherent at baseline, compared with 58.3% for clients nonadherent at baseline). Second-order transition matricies offered additional predictive utility. Multivariate results indicated that, for some, it was the transition from a desirable to an undesirable state (e.g., from no illicit drug use to illicit drug use) that increased the likelihood of nonadherence, rather than the presence of these characteristics over time. Findings illustrate the importance of multiple, periodic assessments of adherence and the need to consider strategies to increase stability in the factors affecting adherence to HAART.