Search Results (78)

Kasugamycin (KSM) is easily affected by photolysis, acid–base destruction, and oxidative decomposition in the natural environment, leading to its poor durability and low effective utilization rate, which affects its control effect on plant bacterial diseases. Nanomaterials modified with environment-responsive agents enable the control of the release of pesticides through intelligently responding to external stimuli, thereby improving efficacy and reducing environmental impact. In this study, a pH-responsive controlled release system was constructed using zeolitic imidazolate frameworks (ZIF-93) for the sustained and targeted delivery of KSM. The synthesized KSM@ZIF-93 exhibited a diameter of 63.93 ± 11.19 nm with a drug loading capacity of 20.0%. Under acidic conditions mimicking bacterial infection sites, the Schiff base bonds and coordination bonds in ZIF-93 dissociated, triggering the simultaneous release of KSM and Zn²⁺, achieving a synergistic antibacterial effect. Light stability experiments revealed a 34.81% reduction in UV-induced degradation of KSM when encapsulated in ZIF-93. In vitro antimicrobial assays demonstrated that KSM@ZIF-93 completely inhibited Erwinia amylovora at 200 mg/L and had better antibacterial activity and persistence than KSM and ZIF-93. The field experiment and safety evaluation showed that the control effect of KSM@ZIF-93 on pear fire blight at the concentration of 200 mg/L was (75.19 ± 3.63)% and had no toxic effect on pollen germination. This pH-responsive system not only enhances the stability and bioavailability of KSM but also provides a targeted and environmentally compatible strategy for managing bacterial infections during the flowering period of pear trees. Full article

Mesoporous silica nanoparticles (MSNs) are gaining popularity in nanomedicine due to their large surface area, variable pore size, great biocompatibility, and chemical adaptability. In recent years, the combination of smart polymeric materials with MSNs has transformed the area of regulated drug administration, particularly under stimuli-responsive settings. Polymer-modified MSNs provide increased stability, longer circulation times, and, most crucially, the capacity to respond to diverse internal (pH, redox potential, enzymes, and temperature) and external (light, magnetic field, and ultrasonic) stimuli. These systems allow for the site-specific, on-demand release of therapeutic molecules, increasing treatment effectiveness while decreasing off-target effects. This review presents a comprehensive analysis of recent advancements in the development and application of polymer-functionalized MSNs for stimuli-triggered drug delivery. Key polymeric modifications, including thermoresponsive, pH-sensitive, redox-responsive, and enzyme-degradable systems, are discussed in terms of their design strategies and therapeutic outcomes. The synergistic use of dual or multiple stimuli-responsive polymers is also highlighted as a promising avenue to enhance precision and control in complex biological environments. Moreover, the integration of targeting ligands and stealth polymers such as PEG further enables selective tumor targeting and immune evasion, broadening the potential clinical applications of these nanocarriers. Recent progress in stimuli-triggered MSNs for combination therapies such as chemo-photothermal and chemo-photodynamic therapy is also covered, emphasizing how polymer modifications enhance responsiveness and therapeutic synergy. Finally, the review discusses current challenges, including scalability, biosafety, and regulatory considerations, and provides perspectives on future directions to bridge the gap between laboratory research and clinical translation. Full article

Stimuli-responsive hydrogels have emerged as a promising class of biomaterials for advanced wound healing applications, offering dynamic and controllable responses to the wound microenvironment. These hydrogels are designed to respond to specific stimuli, such as pH, temperature, light, and enzyme activity, enabling precise regulation of drug release, antimicrobial activity, and tissue regeneration. Composite stimuli-responsive hydrogels, by integrating multiple response mechanisms and functions, show potential for addressing the diverse needs of wound healing. This review explores the biological mechanisms of wound healing, the design and classification of composite stimuli-responsive hydrogels, and the key fabrication strategies employed to optimise their properties. Despite their immense potential, unresolved challenges such as biocompatibility, long-term stability, and scalability continue to limit their translation into clinical practice. Future research will focus on integrating hydrogels with smart wearable devices, AI-driven personalised medicine, and 3D bioprinting technologies to develop next-generation wound care solutions. With continuous advancements in biomaterials science and bioengineering, stimuli-responsive hydrogels hold great promise for revolutionising wound management. Full article

Complex anatomical and physiological barriers make the eye a challenging organ to treat from a drug delivery perspective. Currently available treatment methods (topical eyedrops) for anterior segment diseases pose several limitations in terms of bioavailability and patient compliance. Conventional drug delivery methods to treat posterior segment ocular diseases are primarily intravitreal injection (IVT) of solutions. IVT is highly invasive and leads to retinal toxicity, endophthalmitis, and intraocular inflammation, frequently requiring professional administration and frequent clinical visits. Advanced drug delivery treatment strategies could improve patient compliance and convenience. Long-acting drug delivery platforms (biodegradable or nonbiodegradable) provide sustained/controlled release of drugs for at least four to six months. Smart drug delivery alternatives, for instance, in situ forming implants, are injectable formulations that form semisolid-to-solid implants in response to the various stimuli of pH, light, osmolarity, and temperature. Additionally, nanoparticulate drug delivery systems, contact lenses, electrospun patches, and microneedle-based drug delivery systems provide minimally invasive treatment options for ocular disorders. This comprehensive review focuses on advanced drug delivery options for the management of ocular disorders. Full article

Hydrogel particles are essential in biological applications because of their distinctive capacity to retain water and encapsulate active molecules within their three-dimensional structure. Typical particle sizes range from nanometers (10–500 nm) to micrometers (1–500 µm), depending on the specific application and method of preparation. These characteristics render them optimal carriers for the administration of active compounds, facilitating the regulated and prolonged release of pharmaceuticals, including anticancer agents, antibiotics, and therapeutic proteins. Hydrogel particles can exhibit various morphologies, including spherical, rod-shaped, disk-shaped, and core–shell structures. Each shape offers distinct advantages, such as improved circulation time, targeted drug delivery, or enhanced cellular uptake. Additionally, hydrogel particles can be engineered to respond to various stimuli, such as temperature, pH, light, magnetic fields, and biochemical signals. Furthermore, their biocompatibility and capacity to acclimate to many biological conditions make them appropriate for sophisticated applications, including gene treatments, tissue regeneration, and cell therapies. Microfluidics has transformed the creation of hydrogel particles, providing precise control over their dimensions, morphology, and stability. This technique facilitates reproducible and highly efficient production, reducing reagent waste and optimizing drug encapsulation. The integration of microfluidics with hydrogels provides opportunities for the advancement of creative and effective solutions in contemporary medicine. Full article

The gasotransmitter hydrogen sulfide (H₂S; also termed sulfide) generally acts as a vasodilator in the systemic vasculature but causes a paradoxical constriction of pulmonary arteries (PAs). In light of evidence that a fall in the partial pressure in oxygen (pO₂) increases cellular sulfide levels, it was proposed that a rise in sulfide in pulmonary artery smooth muscle cells (PASMCs) is responsible for hypoxic pulmonary vasoconstriction, the contraction of PAs which develops rapidly in lung regions undergoing alveolar hypoxia. In contrast, pulmonary hypertension (PH), a sustained elevation of pulmonary artery pressure (PAP) which can develop in the presence of a diverse array of pathological stimuli, including chronic hypoxia, is associated with a decrease in the expression of sulfide -producing enzymes in PASMCs and a corresponding fall in sulfide production by the lung. Evidence that PAP in animal models of PH can be lowered by administration of exogenous sulfide has led to an interest in using sulfide-donating agents for treating this condition in humans. Notably, intracellular H₂S exists in equilibrium with other sulfur-containing species such as polysulfides and persulfides, and it is these reactive sulfur species which are thought to mediate most of its effects on cells through persulfidation of cysteine thiols on proteins, leading to changes in function in a manner similar to thiol oxidation by reactive oxygen species. This review sets out what is currently known about the mechanisms by which H₂S and related sulfur species exert their actions on pulmonary vascular tone, both acutely and chronically, and discusses the potential of sulfide-releasing drugs as treatments for the different types of PH which arise in humans. Full article

Conventional cancer chemotherapy often struggles with safely and effectively delivering anticancer therapeutics to target tissues, frequently leading to dose-limiting toxicity and suboptimal therapeutic outcomes. This has created a need for novel therapies that offer greater efficacy, enhanced safety, and improved toxicological profiles. Nanocarriers are nanosized particles specifically designed to enhance the selectivity and effectiveness of chemotherapy drugs while reducing their toxicity. A subset of drug delivery systems utilizes stimuli-responsive nanocarriers, which enable on-demand drug release, prevent premature release, and offer spatial and temporal control over drug delivery. These stimuli can be internal (such as pH and enzymes) or external (such as ultrasound, magnetic fields, and light). This review focuses on the mechanics of ultrasound-induced drug delivery and the various nanocarriers used in conjunction with ultrasound. It will also provide a comprehensive overview of key aspects related to ultrasound-induced drug delivery, including ultrasound parameters and the biological effects of ultrasound waves. Full article

Stimuli-responsive nanocomposite gels combine the unique properties of hydrogels with those of nanoparticles, thus avoiding the suboptimal results of single components and creating versatile, multi-functional platforms for therapeutic and diagnostic applications. These hybrid materials are engineered to respond to various internal and external stimuli, such as temperature, pH, light, magnetic fields, and enzymatic activity, allowing precise control over drug release, tissue regeneration, and biosensing. Their responsiveness to environmental cues permits personalized medicine approaches, providing dynamic control over therapeutic interventions and real-time diagnostic capabilities. This review explores recent advances in stimuli-responsive hybrid gels’ synthesis and application, including drug delivery, tissue engineering, and diagnostics. Overall, these platforms have significant clinical potential, and future research is expected to lead to unique solutions to address unmet medical needs. Full article

In cancer therapy, it is essential to selectively release cytotoxic agents into the tumor to prevent the adverse effects associated with anticancer drugs. Thus, in this study, a stimuli-sensitive polymer–drug conjugate was synthesized for selective drug release. Doxorubicin (DOX) and docetaxel (DTX) were conjugated onto novel poly(jasmine lactone) based copolymer via a thioketal (TK) linker. In addition, a photosensitizer (chlorin e6) was attached to the polymer, which served as a reactive oxygen species generator to cleave the TK linker. The conjugate is readily self-assembled into micelles less than 100 nm in size. Micelles demonstrate a notable increase in their ability to cause cell death when exposed to near-infrared (NIR) light on MDA-MB-231 breast cancer cells. The increase in cytotoxicity is higher than that observed with the combination of free DOX and DTX. The accumulation of DOX in the nucleus after release from the micelles (laser irradiation) was also confirmed by confocal microscopy. In the absence of light, micelles did not show any toxicity while the free drugs were found toxic irrespective of the light exposure. The obtained results suggest the targeted drug delivery potential of micelles regulated by the external stimuli, i.e., NIR light. Full article

Over the last decade, scientists have shifted their focus to the development of smart carriers for the delivery of chemotherapeutics in order to overcome the problems associated with traditional chemotherapy, such as poor aqueous solubility and bioavailability, low selectivity and targeting specificity, off-target drug side effects, and damage to surrounding healthy tissues. Nanofiber-based drug delivery systems have recently emerged as a promising drug delivery system in cancer therapy owing to their unique structural and functional properties, including tunable interconnected porosity, a high surface-to-volume ratio associated with high entrapment efficiency and drug loading capacity, and high mass transport properties, which allow for controlled and targeted drug delivery. In addition, they are biocompatible, biodegradable, and capable of surface functionalization, allowing for target-specific delivery and drug release. One of the most common fiber production methods is electrospinning, even though the relatively two-dimensional (2D) tightly packed fiber structures and low production rates have limited its performance. Forcespinning is an alternative spinning technology that generates high-throughput, continuous polymeric nanofibers with 3D structures. Unlike electrospinning, forcespinning generates fibers by centrifugal forces rather than electrostatic forces, resulting in significantly higher fiber production. The functionalization of nanocarriers on nanofibers can result in smart nanofibers with anticancer capabilities that can be activated by external stimuli, such as light. This review addresses current trends and potential applications of light-responsive and dual-stimuli-responsive electro- and forcespun smart nanofibers in cancer therapy, with a particular emphasis on functionalizing nanofiber surfaces and developing nano-in-nanofiber emerging delivery systems for dual-controlled drug release and high-precision tumor targeting. In addition, the progress and prospective diagnostic and therapeutic applications of light-responsive and dual-stimuli-responsive smart nanofibers are discussed in the context of combination cancer therapy. Full article

Cancer is a highly heterogeneous disease and remains a global health challenge affecting millions of human lives worldwide. Despite advancements in conventional treatments like surgery, chemotherapy, and immunotherapy, the rise of multidrug resistance, tumor recurrence, and their severe side effects and the complex nature of the tumor microenvironment (TME) necessitates innovative therapeutic approaches. Recently, stimulus-responsive nanomedicines designed to target TME characteristics (e.g., pH alterations, redox conditions, enzyme secretion) have gained attention for their potential to enhance anticancer efficacy while minimizing the adverse effects of chemotherapeutics/bioactive compounds. Among the various nanocarriers, hydrogels are intriguing due to their high-water content, adjustable mechanical characteristics, and responsiveness to external and internal stimuli, making them promising candidates for cancer therapy. These properties make hydrogels an ideal nanocarrier for controlled drug release within the TME. This review comprehensively surveys the latest advancements in the area of stimulus-responsive hydrogels for cancer therapy, exploring various stimuli-responsive mechanisms, including biological (e.g., pH, redox), chemical (e.g., enzymes, glucose), and physical (e.g., temperature, light), as well as dual- or multi-stimuli responsiveness. Furthermore, this review addresses the current developments and challenges in hydrogels in cancer treatment. Our aim is to provide readers with a comprehensive understanding of stimulus-responsive hydrogels for cancer treatment, offering novel perspectives on their development for cancer therapy and other medical applications. Full article

Biomedicine is constantly evolving to ensure a significant and positive impact on healthcare, which has resulted in innovative and distinct requisites such as hydrogels. Chitosan-based formulations stand out for their versatile utilization in drug encapsulation, transport, and controlled release, which is complemented by their biocompatibility, biodegradability, and non-immunogenic nature. Stimuli-responsive hydrogels, also known as smart hydrogels, have strictly regulated release patterns since they respond and adapt based on various external stimuli. Moreover, they can imitate the intrinsic tissues’ mechanical, biological, and physicochemical properties. These characteristics allow stimuli-responsive hydrogels to provide cutting-edge, effective, and safe treatment. Constant progress in the field necessitates an up-to-date summary of current trends and breakthroughs in the biomedical application of stimuli-responsive chitosan-based hydrogels, which was the aim of this review. General data about hydrogels sensitive to ions, pH, redox potential, light, electric field, temperature, and magnetic field are recapitulated. Additionally, formulations responsive to multiple stimuli are mentioned. Focusing on chitosan-based smart hydrogels, their multifaceted utilization was thoroughly described. The vast application spectrum encompasses neurological disorders, tumors, wound healing, and dermal infections. Available data on smart chitosan hydrogels strongly support the idea that current approaches and developing novel solutions are worth improving. The present paper constitutes a valuable resource for researchers and practitioners in the currently evolving field. Full article

Stimuli-responsive supramolecular polymers are ordered nanosized materials that are held together by non-covalent interactions (hydrogen-bonding, metal-ligand coordination, π-stacking and, host–guest interactions) and can reversibly undergo self-assembly. Their non-covalent nature endows supramolecular polymers with the ability to respond to external stimuli (temperature, light, ultrasound, electric/magnetic field) or environmental changes (temperature, pH, redox potential, enzyme activity), making them attractive candidates for a variety of biomedical applications. To date, supramolecular research has largely evolved in the development of smart water-soluble self-assemblies with the aim of mimicking the biological function of natural supramolecular systems. Indeed, there is a wide variety of synthetic biomaterials formulated with responsiveness to control and trigger, or not to trigger, aqueous self-assembly. The design of responsive supramolecular polymers ranges from the use of hydrophobic cores (i.e., benzene-1,3,5-tricarboxamide) to the introduction of macrocyclic hosts (i.e., cyclodextrins). In this review, we summarize the most relevant advances achieved in the design of stimuli-responsive supramolecular systems used to control transport and release of both diagnosis agents and therapeutic drugs in order to prevent, diagnose, and treat human diseases. Full article

This review addresses the urgent need for more targeted and less toxic cancer treatments by exploring the potential of multi-responsive polymersomes. These advanced nanocarriers are engineered to deliver drugs precisely to tumor sites by responding to specific stimuli such as pH, temperature, light, hypoxia, and redox conditions, thereby minimizing the side effects associated with traditional chemotherapy. We discuss the design, synthesis, and recent applications of polymersomes, emphasizing their ability to improve therapeutic outcomes through controlled drug release and targeted delivery. Moreover, we highlight the critical areas for future research, including the optimization of polymersome–biological interactions and biocompatibility, to facilitate their clinical adoption. Multi-responsive polymersomes emerge as a promising development in nanomedicine, offering a pathway to safer and more effective cancer treatments. Full article

Recently, drug delivery strategies based on nanomaterials have attracted a lot of interest in different kinds of therapies because of their superior properties. Polydopamine (PDA), one of the most interesting materials in nanomedicine because of its versatility and biocompatibility, has been widely investigated in the drug delivery field. It can be easily functionalized to favor processes like cellular uptake and blood circulation, and it can also induce drug release through two kinds of stimuli: NIR light irradiation and pH. In this review, we describe PDA nanomaterials’ performance on drug delivery, based on their size, morphology, and surface charge. Indeed, these characteristics strongly influence the main mechanisms involved in a drug delivery system: blood circulation, cellular uptake, drug loading, and drug release. The understanding of the connections between PDA nanosystems’ properties and these phenomena is pivotal to obtain a controlled design of new nanocarriers based on the specific drug delivery applications. Full article