scholarly journals Piezoelectric Silicon Micropump for Drug Delivery Applications

2021 ◽  
Vol 11 (17) ◽  
pp. 8008
Author(s):  
Agnes Bußmann ◽  
Henry Leistner ◽  
Doris Zhou ◽  
Martin Wackerle ◽  
Yücel Congar ◽  
...  
Keyword(s):  
Physical Activity ◽  
Drug Delivery ◽  
Standard Deviation ◽  
Energy Efficient ◽  
Water Flow Rate ◽  
Medical Applications ◽  
Small Energy ◽  
Microelectromechanical System ◽  
Drug Delivery Devices ◽  
High Repeatability

Subcutaneous injection is crucial for the treatment of many diseases. Especially for regular or continuous injections, automated dosing is beneficial. However, existing devices are large, uncomfortable, visible under clothing, or interfere with physical activity. Thus, the development of small, energy efficient and reliable patch pumps or implantable systems is necessary and research on microelectromechanical system (MEMS) based drug delivery devices has gained increasing interest. However, the requirements of medical applications are challenging and especially the dosing precision and reliability of MEMS pumps are not yet sufficiently evaluated. To enable further miniaturization, we propose a precise 5 × 5 mm2 silicon micropump. Detailed experimental evaluation of ten pumps proves a backpressure capability with air of 12.5 ± 0.8 kPa, which indicates the ability to transport bubbles. The maximal water flow rate is 74 ± 6 µL/min and the pumps’ average blocking pressure is 51 kPa. The evaluation of the dosing precision for bolus deliveries with water and insulin shows a high repeatability of dosed package volumes. The pumps show a mean standard deviation of only 0.02 mg for 0.5 mg packages, and therefore, stay below the generally accepted 5% deviation, even for this extremely small amount. The high precision enables the combination with higher concentrated medication and is the foundation for the development of an extremely miniaturized patch pump.

Novel ethnographic/contextual inquiry techniques for understanding connected device users in their native environment

2017 ◽  
Vol 6 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Erika Bajars ◽  
Molly Larson-Wakeman ◽  
Chris Franzese ◽  
Sherri Biondi
Keyword(s):  
Drug Delivery ◽  
Cystic Fibrosis ◽  
Medication Adherence ◽  
Patient Engagement ◽  
Development Process ◽  
Medical Applications ◽  
Research Facility ◽  
Device Development ◽  
Health Goals ◽  
Drug Delivery Devices

Pharmaceutical and medical device companies are embracing technology to increase patient engagement and improve adherence to costly and sometimes complex medication therapies. One solution includes developing drug delivery devices that connect to mobile medical applications (MMAs) to support patients in managing and tracking their medications. Developing an adherence system requires understanding users in their use environment, their challenges with taking medications, their health goals, and the behaviors to target for change. Device developers have long relied on in-person ethnography or in-person human factors studies in a research facility to gather these data. Unfortunately, this process is time-consuming, labor intensive, and costly. When considering a rare patient population, collecting data in person becomes even more complex. This work explores how collecting patient data using a remote ethnography platform addresses challenges with in-person studies early in the device development process, and shares a case example of the use of remote ethnography to better understand patients with cystic fibrosis (CF) to design and refine a medication adherence system prior to taking prototypes into in-person testing.

Recent In Vitro and In Silico Advances in the Understanding of Intranasal Drug Delivery

2020 ◽  
Vol 26 ◽  
Author(s):  
John Chen ◽  
Andrew Martin ◽  
Warren H. Finlay
Keyword(s):  
Drug Delivery ◽  
In Silico ◽  
Local Drug Delivery ◽  
In Vivo Studies ◽  
Intranasal Drug Delivery ◽  
Nasal Sprays ◽  
In Silico Studies ◽  
Drug Delivery Devices

Background: Many drugs are delivered intranasally for local or systemic effect, typically in the form of droplets or aerosols. Because of the high cost of in vivo studies, drug developers and researchers often turn to in vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways. Objective: To perform a summary of advances in understanding of intranasal drug delivery based on recent in vitro and in silico studies. Conclusion: The turbinates are a common target for local drug delivery applications, and while nasal sprays are able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning optimal parameters for device design, formulation properties and patient technique which would maximize turbinate deposition. Nebulizers are able to more easily target the turbinates, but come with the disadvantage of significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for potential treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal delivery will be useful in the development of the next generation of intranasal drug delivery devices.

Anti-VEGFR2 Antibody-modified Micelle for Triggered Drug Delivery and Effective Therapy of Choroidal Neovascularization

2019 ◽  
Vol 16 (3) ◽  
pp. 258-265
Author(s):  
Kei Takahashi ◽  
Tomomi Masuda ◽  
Mitsunori Harada ◽  
Tadashi Inoue ◽  
Shinsuke Nakamura ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Choroidal Neovascularization ◽  
Pigment Epithelium ◽  
Drug Carrier ◽  
Retinal Pigment ◽  
Laser Coagulation ◽  
Antiangiogenic Agents ◽  
Drug Carrier System ◽  
Novel Drug ◽  
Drug Delivery Devices

Objective: This study aimed to examine whether DC101 (anti-VEGFR2 antibody)- modified micelles have applications as novel drug delivery devices, which allow small molecule antiangiogenic agents to deliver to angiogenic sites on a murine laser-induced choroidal neovascularization (CNV) model. Materials and Method: CNV was induced by photocoagulation on the unilateral eye of each mouse under anesthesia. Immediately after laser coagulation, E7974-loaded DC101-modified micelles and motesanib-loaded DC101-modified micelles were intravitreally administrated. Two weeks after photocoagulation, CNV was visualized using fluorescein-conjugated dextran (MW=2,000 kDa), and the CNV area was measured in retinal pigment epithelium (RPE)-choroidal flat mounts. Results: Intravitreal administration of both DC101-modified micelles loaded with E7974 at 2 µM and motesanib at 2 µM significantly reduced CNV area in the murine laser-induced CNV model at a clearly lower concentration than the effective dose of each agent. Conclusion: These results suggest that DC101-modified micelle might be effective drug carrier system for treating CNV and other ocular angiogenic diseases.

Emerging 3D printing technologies for drug delivery devices: Current status and future perspective

2021 ◽  
Author(s):  
Jiawei Wang ◽  
Yu Zhang ◽  
Niloofar Heshmati Aghda ◽  
Amit Raviraj Pillai ◽  
Rishi Thakkar ◽  
...  
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Current Status ◽  
Future Perspective ◽  
Drug Delivery Devices

Long term habitual vigorous physical activity is associated with lower visit-to-visit systolic blood pressure variability

2020 ◽  
Author(s):  
Xiaoyong Xu ◽  
Xianghong Meng ◽  
Shin-ichi Oka
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Standard Deviation ◽  
Systolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Vigorous Physical Activity ◽  
Systolic Blood Pressure Variability ◽  
Average Real Variability ◽  
Post Hoc

Abstract Objective Our work aimed to investigate the association between vigorous physical activity and visit-to-visit systolic blood pressure variability (BPV). Methods We conducted a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial), a well-characterized cohort of participants randomized to intensive (<120 mmHg) or standard (<140 mmHg) SBP targets. We assessed whether patients with hypertension who habitually engage in vigorous physical activity would have lower visit-to-visit systolic BPV compared with those who do not engage in vigorous physical activity. Visit-to-visit systolic BPV was calculated by standard deviation (SD), average real variability (ARV), and standard deviation independent of the mean (SDIM) using measurements taken during the 1-, 2-, 3-, 6-, 9- and 12-month study visits. A medical history questionnaire assessed vigorous physical activity, which was divided into three categories according to the frequency of vigorous physical activity. Results A total of 7571 participants were eligible for analysis (34.8% female, mean age 67.9±9.3 years). During a follow-up of 1-year, vigorous physical activity could significantly reduce SD, ARV, and SDIM across increasing frequency of vigorous physical activity. There were negative linear trends between frequency of vigorous physical activity and visit-to-visit systolic BPV. Conclusions Long-term engagement in vigorous physical activity was associated with lower visit-to-visit systolic BPV.

scholarly journals Life-course pathways from childhood socioeconomic status to type 2 diabetes in mid-late Chinese adulthood

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoning Zhang ◽  
Xue Jiang ◽  
Mengqi Sha ◽  
Qiong Zhou ◽  
Wen Li ◽  
...  
Keyword(s):  
Physical Activity ◽  
Type 2 Diabetes ◽  
Socioeconomic Status ◽  
Standard Deviation ◽  
Life Course ◽  
Food Shortage ◽  
Late Adulthood ◽  
Childhood Health ◽  
Childhood Socioeconomic Status

AbstractThe relationship between childhood socioeconomic status (SES) and type 2 diabetes (T2D) remains inconclusive, and the pathways and mechanisms driving this relationship have yet to be clarified. This study aimed to examine the pathways linking childhood SES to T2D prevalence in mid-late adulthood in a low- and middle-income country. The incidence of T2D diagnosed in mid-late Chinese adulthood was assessed using self-reports from the Health and Retirement Longitudinal Study (CHARLS). Childhood SES was assessed by the education, occupation, survivorship of the parents and the financial situation of the family, whereas adulthood SES was assessed by education and wage. This study performed structural equation modeling to clarify the direct and indirect pathways from childhood SES to T2D via childhood health, childhood food shortage, adulthood SES and physical activity. A total of 15,132 participants were included, and the prevalence of T2D was 5.24%. This study found that childhood SES was directly associated with T2D in mid-late adulthood, the probability of developing T2D increased by 9.20% of the standard deviation for each decrease in standard deviation in childhood SES. Childhood SES was indirectly associated with T2D via adulthood SES, physical activity, childhood health and food shortage. Adulthood SES and physical activity mainly mediated the indirect pathway from childhood SES and T2D. This study showed direct and indirect pathways from disadvantaged childhood SES to increased risk of T2D in mid-late Chinese adulthood. Childhood SES, adulthood SES, physical activity, childhood health and food shortage were identified as life-course interventional targets that should be considered in the development of effective strategies to reduce the burden of T2D and SES-related health inequities in childhood.

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