(Poly-cyanoacrylate) nanomedicines for cancer and beyond: Lessons learned

Cancer nanomedicine from a clinician-scientist perspective: Lessons and prospects

The nanomedicine field has progressed enormously in the last couple of decades. From a loose group of liposomologists, polymer scientists, chemical engineers, and experts in metal nanoparticles, mesoporous silica, and other nanomaterials, the field has gradually consolidated and has generated vast amounts of research and clinical data, but, until the development of lipid nanoparticle (LNP)-based vaccinations for Covid-19, has remained with low visibility in the clinic. Applications in the cancer field are the most frequently sought projects in nanomedicine. For the last 45 years, my clinical career has mingled with my research career focusing on ways to formulate drugs in liposomes to improve their safety and efficacy in cancer therapy. In this review, I will discuss my contribution to the development of pegylated liposomal doxorubicin and other cancer nanomedicines from my privileged position as a clinician and scientist.

Polymeric Drug Delivery Systems in Biomedicine

Our review examines the key aspects of using polymeric carriers in biomedicine. The section "Polymers for Biomedicine" provides an overview of different types of polymers, their structural features and properties that determine their use as drug delivery vehicles. The section "Polymeric Carriers" characterizes the role of polymeric delivery systems in modern medicine. The main forms of polymeric carriers are described, as well as their key advantages for drug delivery. The section "Preclinical and Clinical Trials of Polymeric Drug Carriers" reviews the examples of clinical and preclinical studies of polymeric forms used for antitumor therapy, therapy for bacterial and infectious diseases. The final section "Targeted Drug Delivery Systems" is devoted to the discussion of approaches, as well as ligands that provide targeted drug delivery using polymeric carriers. We have paid special attention to modern approaches for increasing the efficacy of antibacterial therapy using vector molecules.

Polymeric antibubbles with strong ultrasound imaging capabilities

Antibubbles are liquid droplets encapsulated by a gas film that have recently been explored for on-demand ultrasound-triggered drug release. However, their ultrasound imaging capabilities are limited by their stiff shells stabilized with silica nanoparticles. Here, we develop polymeric antibubbles that generate greater ultrasound contrast than silica-based antibubbles, while showing better stability than conventional polymeric microbubbles.

Nanoplatform Based Intranasal Vaccines: Current Progress and Clinical Challenges

Multiple vaccine platforms have been employed to develop the nasal SARS-CoV-2 vaccines in preclinical studies, and the dominating pipelines are viral vectored as protein-based vaccines. Among them, several viral vectored-based vaccines have entered clinical development. Nevertheless, some unsatisfactory results were reported in these clinical studies. In the face of such urgent situations, it is imperative to rapidly develop the next-generation intranasal COVID-19 vaccine utilizing other technologies. Nanobased intranasal vaccines have emerged as an approach against respiratory infectious diseases. Harnessing the power of nanotechnology, these vaccines offer a noninvasive yet potent defense against pathogens, including the threat of COVID-19. The improvements made in vaccine mucosal delivery technologies based on nanoparticles, such as lipid nanoparticles, polymeric nanoparticles, inorganic nanoparticles etc., not only provide stability and controlled release but also enhance mucosal adhesion, effectively overcoming the limitations of conventional vaccines. Hence, in this review, we overview the evaluation of intranasal vaccine and highlight the current barriers. Next, the modern delivery systems based on nanoplatforms are summarized. The challenges in clinical application of nanoplatform based intranasal vaccine are finally discussed.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

In Vitro Efficacy of Isobutyl Cyanoacrylate Nanoparticles against Fish Bacterial Pathogens and Selection Preference by Rainbow Trout (Oncorhynchus mykiss)

The upsurge in havoc being wreaked by antibiotic-resistant bacteria has led to an urgent need for efficacious alternatives to antibiotics. This study assessed the antibacterial efficacy of two isobutyl cyanoacrylate nanoparticles (iBCA-NPs), D6O and NP30, against major bacterial pathogens of fish. In vivo tests on rainbow trout were preceded by in vitro tests of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). NP30 exhibited higher efficacy than D60, but both iBCA-NPs demonstrated dose-dependent and species-specific in vitro antibacterial properties against the bacterial isolates. Generally, Gram-negative bacteria were more resistant to the iBCA-NPs. Streptococcus iniae, Tenacibaculum maritimum, and Photobacterium damselae were particularly sensitive to both iBCA-NPs. Administered to rainbow trout at 3571.4 mg (iBCA-NP)/kg feed, the iBCA-NPs produced a relative gain rate and survival rates comparable to the control (p > 0.05). The condition factor and the hepatosomatic and viscerosomatic indices of fish were indifferentiable (p > 0.05) between the iBCA-NP groups and the control. The iBCA-NPs caused no alteration in stress, oxidative stress (superoxide dismutase, SOD), plasma complement titer, or lysozyme activity. This study presents the first report of antibacterial activity of iBCA-NPs against Gram-negative bacteria. The results of this study suggest that D60 and NP30 may contribute to reducing the amounts of antibiotics and chemotherapeutic agents used in aquaculture.

Polymeric materials for ultrasound imaging and therapy

Ultrasound (US) is routinely used for diagnostic imaging and increasingly employed for therapeutic applications. Materials that act as cavitation nuclei can improve the resolution of US imaging, and facilitate therapeutic US procedures by promoting local drug delivery or allowing temporary biological barrier opening at moderate acoustic powers. Polymeric materials offer a high degree of control over physicochemical features concerning responsiveness to US, e.g. via tuning chain composition, length and rigidity. This level of control cannot be achieved by materials made of lipids or proteins. In this perspective, we present key engineered polymeric materials that respond to US, including microbubbles, gas-stabilizing nanocups, microcapsules and gas-releasing nanoparticles, and discuss their formulation aspects as well as their principles of US responsiveness. Focusing on microbubbles as the most common US-responsive polymeric materials, we further evaluate the available chemical toolbox to engineer polymer shell properties and enhance their performance in US imaging and US-mediated drug delivery. Additionally, we summarize emerging applications of polymeric microbubbles in molecular imaging, sonopermeation, and gas and drug delivery, based on refinement of MB shell properties. Altogether, this manuscript provides new perspectives on US-responsive polymeric designs, envisaging their current and future applications in US imaging and therapy.

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO2F2)

A SO₂F₂-mediated ring-opening cross-coupling of cyclobutanone oxime derivatives with alkenes was developed for the construction of a range of δ-olefin-containing aliphatic nitriles with (E)-configuration selectivity. This new method features wide substrate scope, mild conditions, and direct N-O activation.

Closed-loop recyclable plastics from poly(ethyl cyanoacrylate)

Ethyl cyanoacrylate is a highly reactive monomer that has been used nearly exclusively to make Super Glue and related fast-setting adhesives. Here, we describe transformation of this highly abundant, readily available monomer into a closed-loop recyclable plastic that could supplant currently used (and often unrecycled/unrecyclable) plastics, such as poly(styrene). We report polymerization conditions, plastic-processing methods, and plastic-recycling protocols for poly(ethyl cyanoacrylate) plastics that make the Super Glue monomer a viable starting material for a next generation of closed-loop recyclable plastics. The processes described are scalable, and the plastics can be recycled in a closed-loop process with >90% yields, even when combined with a heterogeneous mixture of other types of plastic.

Nano-based eye drop: Topical and noninvasive therapy for ocular diseases

Eye drops are the most accessible therapy for ocular diseases, while inevitably suffering from their lower bioavailability which highly restricts the treatment efficacy. The introduction of nanotechnology has attracted considerable interest as it has advantages over conventional ones such as prolonged ocular surface retention time and enhanced ocular barrier penetrating properties, and achieving higher bioavailability and improved treatment efficacy. This review describes various ocular diseases treated with eye drops as well as the physiological and anatomical ocular barriers faced with through drug administration. It also summarizes the recent advances regarding the utilization of nanotechnology in developing eye drops, and how to optimize the nanocarrier-based ocular drug delivery systems. The prospective future research directions for nano-based eye drops are also discussed here.

Turning down the heat: The case for mild hyperthermia and thermosensitive liposomes

"A single disappointing study does not mean an end to the future of ThermoDox®", writes Michael Tardugno (CEO of Celsion Corporation), after announcing the termination of Celsion's second Phase III clinical trial. The OPTIMA trial, as it was known, evaluated their thermosensitive liposome (TSL) formulation of doxorubicin (ThermoDox®) in combination with radiofrequency ablation for the treatment of hepatocellular carcinoma (HCC). The purpose of this perspective is to review the case of ThermoDox and to address questions related to its clinical translation. Specifically, what has prevented the clinical translation of this once highly regarded breakthrough technology? Is this the end of TSLs? What can we learn from the challenges faced in the clinical development of this multi-modal therapy? As formulation scientists working in the field, we continue to believe that heat-triggered drug delivery platforms have tremendous potential as chemotherapy. Herein, we highlight potential limitations in the design of many of the Thermodox clinical trials, and we propose that despite these setbacks, TSLs have the potential to become an effective component of cancer therapy.

Shape stability of ellipsoidal nanomaterials prepared by physical deformation

The nonspherical shape of nanomaterials (NMs) represents a key attribute for controlling their biological behaviors. Analyzing shape stability over time represents a significant concern because nonspherical NMs are likely to rearrange into a thermodynamically more stable spherical shape. In this investigation, ellipsoidal NMs were designed by physical deformation of core/shell nanospheres composed of poly(isobutylcyanoacrylate) and chitosan or a mixture of chitosan and thiolated chitosan. After optimizing the process parameters for designing ellipsoidal NMs, the shape stability during storage was investigated for 6 months at different temperatures (4 °C, 20 °C and 40 °C). The NM shape was examined by analyzing the aspect ratio from images obtained by electron microscopy techniques. The results demonstrated the feasibility of designing shape-persistent ellipsoidal NMs by physical deformation of spherical particles.