Container Closure and Delivery Considerations for Intravitreal Drug Administration.

Intravitreal (IVT) administration of therapeutics is the standard of care for treatment of back-of-eye disorders. Although a common procedure performed by retinal specialists, IVT administration is associated with unique challenges related to drug product, device and the procedure, which may result in adverse events. Container closure configuration plays a crucial role in maintaining product stability, safety, and efficacy for the intended shelf-life.

Predicting bioavailability of monoclonal antibodies after subcutaneous administration: Open innovation challenge.

Despite the increasing trend towards subcutaneous delivery of monoclonal antibodies, factors influencing the subcutaneous bioavailability of these molecules remain poorly understood. To address critical knowledge gaps and issues during development of subcutaneous dosage forms for monoclonal antibodies, the Subcutaneous Drug Delivery and Development Consortium was convened in 2018 as a pre-competitive collaboration of recognized industry experts. One of the Consortium's eight problem statements highlights the challenges of predicting human bioavailability of subcutaneously administered monoclonal antibodies due to a lack of reliable in vitro and preclinical in vivo predictive models.

Device design methodology and formulation of a protein therapeutic for sustained release intraocular delivery.

Despite years of effort, sustained delivery of protein therapeutics remains an unmet need due to three primary challenges - dose, duration, and stability. The work presented here provides a design methodology for polycaprolactone reservoir-based thin film devices suitable for long-acting protein delivery to the back of the eye. First, the challenge of formulating highly concentrated protein in a device reservoir was addressed by improving stability with solubility-reducing excipients.

Simultaneous Non-invasive Analysis of DNA Condensation and Stability by Two-step QD-FRET.

Nanoscale vectors comprised of cationic polymers that condense DNA to form nanocomplexes are promising options for gene transfer. The rational design of more efficient nonviral gene carriers will be possible only with better mechanistic understanding of the critical rate-limiting steps, such as nanocomplex unpacking to release DNA and degradation by nucleases. We present a two-step quantum dot fluorescence resonance energy transfer (two-step QD-FRET) approach to simultaneously and non-invasively analyze DNA condensation and stability.

Combining QD-FRET and microfluidics to monitor DNA nanocomplex self-assembly in real-time.

Advances in genomics continue to fuel the development of therapeutics that can target pathogenesis at the cellular and molecular level. Typically functional inside the cell, nucleic acid-based therapeutics require an efficient intracellular delivery system. One widely adopted approach is to complex DNA with a gene carrier to form nanocomplexes via electrostatic self-assembly, facilitating cellular uptake of DNA while protecting it against degradation.

The convergence of quantum-dot-mediated fluorescence resonance energy transfer and microfluidics for monitoring DNA polyplex self-assembly in real time.

We present a novel convergence of quantum-dot-mediated fluorescence resonance energy transfer (QD-FRET) and microfluidics, through which molecular interactions were precisely controlled and monitored using highly sensitive quantum-dot-mediated FRET. We demonstrate its potential in studying the kinetics of self-assembly of DNA polyplexes under laminar flow in real time with millisecond resolution. The integration of nanophotonics and microfluidics offers a powerful tool for elucidating the formation of polyelectrolyte polyplexes, which is expected to provide better control and synthesis of uniform and customizable polyplexes for future nucleic acid-based therapeutics.

Quantitative comparison of intracellular unpacking kinetics of polyplexes by a model constructed from quantum dot-FRET.

A major challenge for non-viral gene delivery is gaining a mechanistic understanding of the rate-limiting steps. A critical barrier in polyplex-mediated gene delivery is the timely unpacking of polyplexes within the target cell to liberate DNA for efficient gene transfer. In this study, the component plasmid DNA and polymeric gene carrier were individually labeled with quantum dots (QDs) and Cy5 dyes, respectively, as a donor and acceptor pair for fluorescence resonance energy transfer (FRET).

Evaluating the intracellular stability and unpacking of DNA nanocomplexes by quantum dots-FRET.

We demonstrate a highly sensitive method to characterize the structural composition and intracellular fate of polymeric DNA nanocomplexes, formed by condensing plasmid DNA with cationic polymers through electrostatic interactions. Rational design of more efficient polymeric gene carriers will be possible only with mechanistic insights of the rate-limiting steps in the non-viral gene transfer process. To characterize the composition and binding dynamics of nanocomplexes, plasmid and its polymer carrier within nanocomplexes were labeled with quantum dots (QDs) and fluorescent organic dyes, respectively, as a donor and acceptor pair for fluorescence resonance energy transfer (FRET).

Dynamic imaging of allogeneic mesenchymal stem cells trafficking to myocardial infarction.

Background: Recent results from animal studies suggest that stem cells may be able to home to sites of myocardial injury to assist in tissue regeneration. However, the histological interpretation of postmortem tissue, on which many of these studies are based, has recently been widely debated.

Methods And Results: With the use of the high sensitivity of a combined single-photon emission CT (SPECT)/CT scanner, the in vivo trafficking of allogeneic mesenchymal stem cells (MSCs) colabeled with a radiotracer and MR contrast agent to acute myocardial infarction was dynamically determined.

MR imaging of biodegradable polymeric microparticles: a potential method of monitoring local drug delivery.

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) was encapsulated into biodegradable, bioadhesive polymeric microparticles to enable noninvasive monitoring of their local intravesical delivery with MRI. The microparticles were characterized by contrast agent encapsulation and release kinetics, T(1) relaxation rates, and contrast enhancement in vivo. The level of Gd-DTPA loading into microparticles was 14.

Detection of dual-gene expression in arteries using an optical imaging method.

We evaluate the in vivo use of an optical imaging method to detect the vascular expression of green fluorescent protein (GFP) or red fluorescent protein (RFP), and to detect the simultaneous expression of GFP and RFP after transduction into arteries by a dual-promoter lentiviral vector driving their concurrent expression. This method involves using a charge-coupled device camera to detect fluorescence, a fiber optic probe to transmit light, and optical filters to distinguish each marker. In animal models, these vectors are locally delivered to target arteries, whereas the gene for a nonfluorescent cell-surface protein is transduced into contralateral arteries as the sham control.

In vivo US monitoring of catheter-based vascular delivery of gene microspheres in pigs: feasibility.

In this study, the authors tested the feasibility of using ultrasonography (US) to monitor catheter-based vascular gene microsphere delivery. Polymeric biodegradable microspheres (mean diameter, 5 microm) were prepared by using a double-emulsion technique to encapsulate DNA-plasmid-encoding green fluorescent protein (GFP) genes. With use of gene-delivery catheters, GFP microspheres were locally delivered into the left femoral arterial walls of six pigs; the contralateral arteries were not infused with microspheres and thus served as negative control vessels.