Development of prolonged drug delivery system using electrospun cellulose acetate/polycaprolactone nanofibers: future subcutaneous implantation

Implantable drug delivery systems (IDDSs) play a vital role in treating chronic diseases by reducing dosing frequency and enhancing drug efficacy due to targeted delivery. In the present study, an IDDS was developed from electrospun cellulose acetate (CA) and polycaprolactone (PCL) nanofiber membranes. The implant core consists of a drug-loaded CA nanofiber (CA + Vit.D3) enclosed in a rate limiting of the PCL membrane (CA + Vit.D3/PCL). The CA and PCL nanofibrous membranes were characterized using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy, X-ray diffraction, and UV–Vis spectroscopy. This research also investigated in-vitro cytotoxicity and whether the PCL membrane prolonged drug delivery or led to enhanced mechanical properties. A smooth, beadless surface morphology was observed with fiber diameters of 325 ± 101 nm and 333 ± 79 nm for CA and PCL, respectively. In-vitro drug release and tensile testing showed that surrounding the core's implants with a PCL membrane improved mechanical properties and kinetic drug release. The modulus and tensile strength of CA + Vit.D3/PCL were 161 ± 14 and 13.07 ± 2.5 MPa, respectively—these values were significantly higher than those obtained for CA + Vit.D3 (132 ± 52 MPa and 8.16 ± 2.36 MPa, respectively). The drug release pattern exhibited by CA + Vit.D3 was burst release, which fits the first-order kinetic model. In contrast, CA + Vit.D3/PCL exhibited slow drug release, which fits the zero-order kinetic model. In conclusion, based on the outcomes and facility of the technologies outlined in this article, electrospun CA and PCL nanofibers are suitable for developing long-term IDDSs

Worldwide Disparities in Recovery of Cardiac Testing 1 Year Into COVID-19

Background: The extent to which health care systems have adapted to the COVID-19 pandemic to provide necessary cardiac diagnostic services is unknown. Objectives: The aim of this study was to determine the impact of the pandemic on cardiac testing practices, volumes and types of diagnostic services, and perceived psychological stress to health care providers worldwide. Methods: The International Atomic Energy Agency conducted a worldwide survey assessing alterations from baseline in cardiovascular diagnostic care at the pandemic's onset and 1 year later. Multivariable regression was used to determine factors associated with procedure volume recovery. Results: Surveys were submitted from 669 centers in 107 countries. Worldwide reduction in cardiac procedure volumes of 64% from March 2019 to April 2020 recovered by April 2021 in high- and upper middle-income countries (recovery rates of 108% and 99%) but remained depressed in lower middle- and low-income countries (46% and 30% recovery). Although stress testing was used 12% less frequently in 2021 than in 2019, coronary computed tomographic angiography was used 14% more, a trend also seen for other advanced cardiac imaging modalities (positron emission tomography and magnetic resonance; 22%-25% increases). Pandemic-related psychological stress was estimated to have affected nearly 40% of staff, impacting patient care at 78% of sites. In multivariable regression, only lower-income status and physicians’ psychological stress were significant in predicting recovery of cardiac testing. Conclusions: Cardiac diagnostic testing has yet to recover to prepandemic levels in lower-income countries. Worldwide, the decrease in standard stress testing is offset by greater use of advanced cardiac imaging modalities. Pandemic-related psychological stress among providers is widespread and associated with poor recovery of cardiac testing