Electrospinning/Electrospray of Ferrocene Containing Copolymers to Fabricate ROS-Responsive Particles and Fibers

A novel transdermal drug delivery system: drug-loaded ROS-responsive ferrocene fibers for effective photoprotective and wound healing activity

The present study proposes an innovative transdermal drug delivery system using ferrocene-incorporated fibers to enhance the bioavailability and therapeutic efficacy of ascorbyl tetraisopalmitate. Using electrospinning technology, the authors created ferrocene polymer fibers capable of highly efficient drug encapsulation and controlled release in response to reactive oxygen species commonly found in wound sites. The approach improves upon previous methods significantly by offering higher drug loading capacities and sustained release, directly targeting diseased cells. The results confirm the potential of ferrocene fibers for localized drug delivery, potentially reducing side effects and increasing patient convenience. The method could facilitate the application of bioactive compounds in medical textiles and targeted therapy.

Cleavage and Noncleavage Chemistry in Reactive Oxygen Species (ROS)-Responsive Materials for Smart Drug Delivery

The design and development of advanced drug delivery systems targeting reactive oxygen species (ROS) have gained significant interest in recent years for treating various diseases, including cancer, psychiatric diseases, cardiovascular diseases, neurological diseases, metabolic diseases, and chronic inflammations. Integrating specific chemical bonds capable of effectively responding to ROS and triggering drug release into the delivery system is crucial. In this Review, we discuss commonly used conjugation linkers (chemical bonds) and categorize them into two groups: cleavable linkers and noncleavable linkers. Our goal is to clarify their unique drug release mechanisms from a chemical perspective and provide practical organic synthesis approaches for their efficient production. We showcase numerous significant examples to demonstrate their synthesis routes and diverse applications. Ultimately, we strive to present a comprehensive overview of cleavage and noncleavage chemistry, offering insights into the development of smart drug delivery systems that respond to ROS.

Microneedles coated with composites of phenylboronic acid-containing polymer and carbon nanotubes for glucose measurements in interstitial fluids

A microneedle (MN) sensor coated with a sensing composite material was proposed for measuring glucose concentrations in interstitial fluid (ISF). The sensing composite material was prepared by blending a polymer containing glucose-responsive phenylboronic acid (PBA) moieties (i.e., polystyrene-block-poly(acrylic acid-co-acrylamidophenylboronic acid)) with conductive carbon nanotubes (CNTs). The polymer exhibited reversible swelling behavior in response to glucose concentrations, which influenced the distribution of the embedded CNTs, resulting in sensitive variations in electrical percolation, even when coated onto a confined surface of the MN in the sensor. We varied the ratio of PBA moieties and the loading amount of CNTs in the sensing composite material of the MN sensor and tested them in vitro using an ISF-mimicking gel with physiological glucose concentrations to determine the optimal sensitivity conditions. When tested in animal models with varying blood glucose concentrations, the MN sensor coated with the selected sensing material exhibited a strong correlation between the measured electrical currents and blood glucose concentrations, showing accuracy comparable to that of a glucometer in clinical use.

Biodegradable Nanofiber/Metal-Organic Framework/Cotton Air Filtration Membranes Enabling Simultaneous Removal of Toxic Gases and Particulate Matter

The typical filters that protect us from harmful components, such as toxic gases and particulate matter (PM), are made from petroleum-based materials, which need to be replaced with other environmentally friendly materials. Herein, we demonstrate a route to fabricate biodegradable and dual-functional filtration membranes that effectively remove PM and toxic gases. The membrane was integrated using two layers: (i) cellulose-based nanofibers for PM filtration and (ii) metal-organic framework (MOF)-coated cotton fabric for removal of toxic gases. Zeolitic imidazolate framework (ZIF-8) was grown from the surface of the cotton fabric by the treatment of cotton fabric with an organic precursor solution and subsequent immersion in an inorganic precursor solution. Cellulose acetate nanofibers (NFs) were deposited on the MOF-coated cotton fabric via electrospinning. At the optimal thickness of the NF layer, the quality factor of 18.8 × 10-2 Pa-1 was achieved with a filtration efficiency of 93.1%, air permeability of 19.0 cm3/cm2/s, and pressure drop of 14.2 Pa. The membrane exhibits outstanding gas adsorption efficiencies (>99%) for H2S, formaldehyde, and NH3. The resulting membrane was highly biodegradable, with a weight loss of 62.5% after 45 days under standard test conditions. The proposed strategy should provide highly sustainable material platforms for practical multifunctional membranes in personal protective equipment.

Stimuli-responsive electrospun nanofibers for drug delivery, cancer therapy, wound dressing, and tissue engineering

The stimuli-responsive nanofibers prepared by electrospinning have become an ideal stimuli-responsive material due to their large specific surface area and porosity, which can respond extremely quickly to external environmental incitement. As an intelligent drug delivery platform, stimuli-responsive nanofibers can efficiently load drugs and then be stimulated by specific conditions (light, temperature, magnetic field, ultrasound, pH or ROS, etc.) to achieve slow, on-demand or targeted release, showing great potential in areas such as drug delivery, tumor therapy, wound dressing, and tissue engineering. Therefore, this paper reviews the recent trends of stimuli-responsive electrospun nanofibers as intelligent drug delivery platforms in the field of biomedicine.

Photoluminescent Scaffolds Based on Natural and Synthetic Biodegradable Polymers for Bioimaging and Tissue Engineering

Non-invasive visualization and monitoring of tissue-engineered structures in a living organism is a challenge. One possible solution to this problem is to use upconversion nanoparticles (UCNPs) as photoluminescent nanomarkers in scaffolds. We synthesized and studied scaffolds based on natural (collagen-COL and hyaluronic acid-HA) and synthetic (polylactic-co-glycolic acids-PLGA) polymers loaded with β-NaYF₄:Yb³⁺, Er³⁺ nanocrystals (21 ± 6 nm). Histomorphological analysis of tissue response to subcutaneous implantation of the polymer scaffolds in BALB/c mice was performed. The inflammatory response of the surrounding tissues was found to be weak for scaffolds based on HA and PLGA and moderate for COL scaffolds. An epi-luminescent imaging system with 975 nm laser excitation was used for in vivo visualization and photoluminescent analysis of implanted scaffolds. We demonstrated that the UCNPs' photoluminescent signal monotonously decreased in all the examined scaffolds, indicating their gradual biodegradation followed by the release of photoluminescent nanoparticles into the surrounding tissues. In general, the data obtained from the photoluminescent analysis correlated satisfactorily with the histomorphological analysis.

Stimuli-Responsive Nanoparticles for Controlled Drug Delivery in Synergistic Cancer Immunotherapy

Cancer immunotherapy has achieved promising clinical progress over the recent years for its potential to treat metastatic tumors and inhibit their recurrences effectively. However, low patient response rates and dose-limiting toxicity remain as major dilemmas for immunotherapy. Stimuli-responsive nanoparticles (srNPs) combined with immunotherapy offer the possibility to amplify anti-tumor immune responses, where the weak acidity, high concentration of glutathione, overexpressions of enzymes, and reactive oxygen species, and external stimuli in tumors act as triggers for controlled drug release. This review highlights the design of srNPs based on tumor microenvironment and/or external stimuli to combine with different anti-tumor drugs, especially the immunoregulatory agents, which eventually realize synergistic immunotherapy of malignant primary or metastatic tumors and acquire a long-term immune memory to prevent tumor recurrence. The authors hope that this review can provide theoretical guidance for the construction and clinical transformation of smart srNPs for controlled drug delivery in synergistic cancer immunotherapy.

Reactive oxygen species-sensitive polymeric nanocarriers for synergistic cancer therapy

Reactive oxygen species (ROS)-responsive nanocarriers have aroused widespread interest in recent years. On the one hand, a high ROS level has been detected in many types of tumor cells. On the other hand, ROS generation is also induced during photodynamic, sonodynamic, or chemodynamic therapy. In addition, multiple types of polymers are sensitive to ROS. Therefore, numerous ROS-responsive polymeric nanocarriers with unique ROS-responsive characteristics have been developed. This review discusses ROS-sensitive polymeric nanocarriers to improve drug delivery efficacy. In particular, ROS-responsive nanocarriers for synergistic cancer therapy are highlighted. The development of novel ROS-sensitive nanocarriers holds great potential for combining ROS-mediated therapy, such as photodynamic therapy, and other therapies to achieve synergistic anticancer efficacy. STATEMENT OF SIGNIFICANCE: Reactive oxygen species (ROS)-responsive nanocarriers aroused widespread interest in recent years. On the one hand, a high level of ROS has been found in many types of tumor cells. On the other hand, the ROS generation can also be induced during the photodynamic, sonodynamic, or chemodynamic therapy. Besides, multiple types of polymers were sensitive to the ROS. Therefore, numerous ROS-responsive polymeric nanocarriers with unique ROS responsive characteristics have been developed. This review focuses on the ROS-sensitive polymeric nanocarriers to improve drug delivery efficacy for synergistic cancer therapy.