Collagen-based materials, renowned for their biocompatibility and minimal immunogenicity, serve as exemplary substrates in a myriad of biomedical applications. Collagen-based micro/nanogels, in particular, are valued for their increased surface area, tunable degradation rates, and ability to facilitate targeted drug delivery, making them instrumental in advanced therapeutics and tissue engineering endeavors. Although extensive reviews on micro/nanogels exist, they tend to cover a wide range of biomaterials and lack a specific focus on collagen-based materials. The current review offers an in-depth look into the manufacturing technologies, drug release mechanisms, and biomedical applications of collagen-based micro/nanogels to address this gap. First, we provide an overview of the synthetic strategies that allow the precise control of the size, shape, and mechanical strength of these collagen-based micro/nanogels by controlling the degree of cross-linking of the materials. These properties are crucial for their performance in biomedical applications. We then highlight the environmental responsiveness of these collagen-based micro/nanogels, particularly their sensitivity to enzymes and pH, which enables controlled drug release under various pathological conditions. The discussion then expands to include their applications in cancer therapy, antimicrobial treatments, bone tissue repair, and imaging diagnosis, emphasizing their versatility and potential in these critical areas. The challenges and future perspectives of collagen-based micro/nanogels in the field are discussed at the end of the review, with an emphasis on the translation to clinical practice. This comprehensive review serves as a valuable resource for researchers, clinicians, and scientists alike, providing insights into the current state and future directions of collagen-based micro/nanogel research and development.
Collagen/chemistry* ; Drug Delivery Systems/methods* ; Humans ; Tissue Engineering/methods* ; Animals ; Biocompatible Materials/chemistry*

Cancer represents a major worldwide disease burden marked by escalating incidence and mortality. While therapeutic advances persist, developing safer and precisely targeted modalities remains imperative. Nanomedicines emerges as a transformative paradigm leveraging distinctive physicochemical properties to achieve tumor-specific drug delivery, controlled release, and tumor microenvironment modulation. By synergizing passive enhanced permeation and retention effect-driven accumulation and active ligand-mediated targeting, nanoplatforms enhance pharmacokinetics, promote tumor microenvironment enrichment, and improve cellular internalization while mitigating systemic toxicity. Despite revolutionizing cancer therapy through enhanced treatment efficacy and reduced adverse effects, translational challenges persist in manufacturing scalability, longterm biosafety, and cost-efficiency. This review systematically analyzes cutting-edge nanoplatforms, including polymeric, lipidic, biomimetic, albumin-based, peptide engineered, DNA origami, and inorganic nanocarriers, while evaluating their strategic advantages and technical limitations across three therapeutic domains: immunotherapy, chemotherapy, and radiotherapy. By assessing structure-function correlations and clinical translation barriers, this work establishes mechanistic and translational references to advance oncological nanomedicine development.
Humans ; Neoplasms/radiotherapy* ; Immunotherapy/methods* ; Nanoparticles/chemistry* ; Animals ; Nanomedicine/methods* ; Drug Delivery Systems/methods* ; Drug Carriers/chemistry* ; Radiotherapy/methods*

Ischemic stroke (IS) ranks as a leading cause of death and disability globally. The blood-brain barrier (BBB) poses significant challenges for effective drug delivery to brain tissues. Recent decades have seen the development of targeted nanomedicine and biomimetic technologies, sparking substantial interest in biomimetic drug delivery systems for treating IS. These systems are devised by utilizing or replicating natural cells and their derivatives, offering promising new pathways for detection and transport across the BBB. Their multifunctionality and high biocompatibility make them effective treatment options for IS. In addition, the incorporation of engineering techniques has provided these biomimetic drug delivery systems with active targeting capabilities, enhancing the accumulation of therapeutic agents in ischemic tissues and specific cell types. This improvement boosts drug transport and therapeutic efficacy. However, it is crucial to thoroughly understand the advantages and limitations of various engineering strategies employed in constructing biomimetic delivery systems. Selecting appropriate construction methods based on the characteristics of the disease is vital to achieving optimal treatment outcomes. This review summarizes recent advancements in three types of engineered biomimetic drug delivery systems, developed from natural cells and their derivatives, for treating IS. It also discusses their effectiveness in application and potential challenges in future clinical translation.
Humans ; Drug Delivery Systems/methods* ; Ischemic Stroke/drug therapy* ; Animals ; Blood-Brain Barrier/metabolism* ; Stroke/drug therapy*

OBJECTIVE: To review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. METHODS: An extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. RESULTS: By incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. CONCLUSION While nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
Peripheral Nerve Injuries/surgery* ; Nerve Regeneration ; Humans ; Tissue Scaffolds ; Animals ; Guided Tissue Regeneration/methods* ; Tissue Engineering/methods* ; Biocompatible Materials ; Peripheral Nerves ; Drug Delivery Systems

OBJECTIVE: To summarize recent research progress in hydrogel-based growth factors for treatment of intervertebral disc degeneration (IDD). METHODS: The relevant literature on hydrogel-based growth factors for IDD treatment at home and abroad was extensively reviewed, and their advantages and therapeutic effects in repairing IDD were analyzed and summarized. RESULTS: Hydrogels exhibit high hydration, biocompatibility, and biodegradability, enabling targeted delivery and sustained release of growth factors such as growth differentiation factors and transforming growth factors. This facilitates enhanced efficacy in promoting cell proliferation, extracellular matrix synthesis, and reducing inflammatory responses. Consequently, hydrogels demonstrate broad application prospects in the repair of IDD. CONCLUSION Research on hydrogel-based growth factors for treating IDD demonstrates advantages such as avoiding disc damage caused by repeated injections and controlling growth factor release concentrations. However, drawbacks include the limited variety of loaded growth factors and the need to verify the long-term stability and biocompatibility of hydrogels. Therefore, further research is required on aspects such as the types of loaded growth factors and the long-term stability and biocompatibility of hydrogels to establish an experimental foundation for their clinical application.
Intervertebral Disc Degeneration/therapy* ; Hydrogels/chemistry* ; Humans ; Intercellular Signaling Peptides and Proteins/administration & dosage* ; Biocompatible Materials/chemistry* ; Animals ; Tissue Engineering/methods* ; Cell Proliferation/drug effects* ; Drug Delivery Systems

Research in photodynamic therapy (PDT) primarily focuses on enhancing light penetration depth, improving oxygen supply, and optimizing photosensitizer delivery. Notably, the delivery efficiency of the photosensitizer is crucial for therapeutic efficacy. Carboxyl-substituted phthalocyanines, as important photosensitizing molecules, possess unique chemical modification sites that enable direct targeted delivery or integration into diverse delivery systems. Their synthesis predominantly employs mixed- or cross-condensation, selective synthesis, and axial modification strategies to introduce carboxyl groups. However, their inherent hydrophobicity significantly hinders effective delivery. To address this limitation, modifications with peptides or quaternary ammonium salt derivatives may facilitate precise delivery to tumor cells and pathogens. With advances in nanotechnology, carboxyl-substituted phthalocyanines can serve as key photosensitizer modules, effectively integrated into nanomaterials such as biomacromolecules, inorganic metals, and polymers for both active and passive delivery. Recently, researchers have exploited the π-π stacking and other intermolecular forces among carboxyl-substituted phthalocyanine molecules to drive their self-assembly into nano-micelles, enabling carrier-free delivery or co-delivery with other therapeutic agents for synergistic effects. This review systematically outlines the synthesis strategies for carboxyl-substituted phthalo-cyanines. Taking mono-carboxyl-substituted zinc phthalocyanine as a model molecule, the performance of three delivery modalities were compared: single-molecule targeted delivery, nanocarrier-encapsulated delivery, and carrier-free self-assembled delivery, in terms of PDT efficacy, biocompatibility, and imaging-guided tracing capabilities, to provide a systematic technical framework for the rational design of novel modular photosensitizers and to advance the clinical translation of PDT in precision oncology and anti-infective therapy.
Photochemotherapy/methods* ; Indoles/administration & dosage* ; Isoindoles ; Photosensitizing Agents/administration & dosage* ; Drug Delivery Systems ; Humans

Neutrophils, as the most abundant immune cells in the human body, possess the inherent ability to rapidly migrate to sites of inflammation and infection. Novel drug delivery systems leveraging neutrophils capitalize on their natural targeting and phagocytic capabilities to achieve precise drug delivery. Efficient drug loading into neutrophils within neutrophil-based delivery systems can be achieved through physical adsorption, chemical conjugation, and phagocytosis. Design strategies emphasize carrier selection and targeting ligand design to enhance delivery precision. Compared to traditional drug delivery systems, neutrophil-based systems offer significant advantages, including excellent biocompatibility and strong tissue penetration. These properties can significantly improve drug bioavailability and reduce adverse reactions associated with non-target tissue accumulation. However, these systems also face several challenges that require resolution, such as difficulties in cell collection and preservation, the need for stability optimization, challenges in large-scale production, and a lengthy clinical translation cycle. In disease treatment applications, neutrophil-based drug delivery systems enable precise delivery of anti-cancer drugs to tumor sites, potentially disrupting immunosuppression of the tumor microenvironment and enhancing therapeutic efficacy. For brain diseases, their unique ability to cross the blood-brain barrier facilitates effective drug delivery. In chronic inflammatory diseases, neutrophil-based systems can precisely deliver anti-inflammatory agents to mitigate inflammation. Performance enhancements for neutrophil-based systems can be achieved by the development of novel nanomaterials and optimization of targeting ligand affinity, thereby improving the accuracy and efficiency of drug delivery. This review comprehensively explores the design strategies, advantages, challenges, and future directions of neutrophil-based drug delivery systems. It summarizes research progress in disease treatment applica-tions, aiming to offer key insights for the development of novel drug delivery systems and advance precision medicine and targeted therapy.
Humans ; Drug Delivery Systems/methods* ; Neutrophils ; Phagocytosis ; Drug Carriers ; Blood-Brain Barrier ; Neoplasms/drug therapy*

Myocardial infarction is a cardiovascular disease with high morbidity and mortality rates. Hydrogel biomaterials mimicking the extracellular matrix have recently been shown to demonstrate excellent biocompatibility, low immunogenicity, favorable biodegradability, and multifunctionality, showcasing significant potential for treatment of myocardial infarction. Hydrogels can provide mechanical support to the damaged myo-cardium, alleviating pathological remodeling. Moreover, their porous structure makes them ideal carriers for localized and sustained drug delivery. Hydrogels derived from various matrices-including polysaccharides, polypeptides, proteins, decellularized extracellular matrix, and synthetic polymers-exhibit distinct properties in terms of biocompatibility, mechanical performance, and drug delivery capacity. These hydrogels support tissue regeneration and enable targeted release of diverse therapeutics, meeting the various therapeutic demands for myocardial repair. In the infarcted myocardial microenvironment, endogenous signals such as low pH, specific enzyme expression, and elevated levels of reactive oxygen species can trigger responsive drug release from hydrogels, while external physical stimuli-such as ultrasound, light, and magnetic fields-can also be employed to precisely control the release process, thereby enhancing therapeutic efficacy and reducing systemic side effects. This review summarizes recent advances in hydrogel-based drug delivery systems for treatment of myocardial infarction, focusing particularly on the characteristics and advantages of different hydrogel materials for myocardial repair. Furthermore, the responsive drug release behavior of hydrogels is analyzed in the context of the cardiac injury microenvironment, providing a reference for future research.
Hydrogels/chemistry* ; Myocardial Infarction/drug therapy* ; Humans ; Drug Delivery Systems/methods* ; Biocompatible Materials ; Drug Carriers

Nano-drug delivery systems offer significant benefits, including high specific surface area, structural and functional diversity, and surface modifiability. When formulated as inhalable nano-formulation, these can not only enable precise pulmonary drug delivery but also improve pulmonary bioavailability and enhance thera-peutic efficacy. Currently, there are four types of inhalable nano-formulations for the treatment of respiratory diseases. Inhalable liquid preparations exhibit facile manufactur-ability and broad applicability yet demonstrate compromised stability during aerosolization. Through structure optimization, surface modification, dispersion medium optimization and device improvement, the atomization stability of nano-drug has been enhanced. Pressurized metered-dose inhalers loaded with nano-drugs face technical challenges: conventional propellants may dissolve nano-carriers, whereas co-solvents like ethanol compromise delivery efficiency. Thus, it is necessary to develop novel propellants that provide thermodynamic stability and optimal delivery performance. Nano-drug formulations in dry powder inhalers exhibit relatively favorable physical stability, however, pulmonary delivery efficiency and nanoparticles integrity during processing remain problematic. Pulmonary delivery efficiency can be improved by employing strategies such as blending excipients to promote the re-dispersibility of nanoparticle agglomerates, optimizing the design of microcarrier, and innovating preparation processes. In contrast, soft mist inhalers are an ideal option for pulmonary delivery of nano-drugs owing to their gentle and efficient atomization properties to maintain nano-drug integrity. This review summarizes the inhalable nano-formulations and focuses on challenges and proposed strategies encoun-tered in integrating nano-drug delivery systems and inhalation drug delivery systems. It aims to provide references for the future development of inhalable nano-formulations.
Administration, Inhalation ; Humans ; Drug Delivery Systems/methods* ; Nanoparticles ; Dry Powder Inhalers ; Nanoparticle Drug Delivery System ; Drug Compounding ; Metered Dose Inhalers ; Drug Carriers

Ultrasound has emerged as a non-invasive neural modulation technique. Its mechanisms of action in the brain involve mechanical, cavitation, and thermal effects, which modulate neural activity by activating mechanosensitive ion channels, enhancing cell permeability, and improving blood circulation. The ultrasound-piezo-electric systems, based on the coupling between ultrasound and piezoelectric materials, can generate wireless electrical stimulation to promote neural repair, significantly improving therapeutic outcomes for neurodegenerative diseases and showing potential as a replacement for traditional invasive deep brain stimulation techniques. The ultrasound-responsive piezoelectric drug delivery system combines mechano-electrical conversion capability of piezoelectric materials with the non-invasive penetration advantage of ultrasound. This system achieves synergistic therapeutic effects for neurodegenerative diseases through on-demand drug release and wireless electrical stimulation in deep brain regions. It can effectively overcome the blood-brain barrier limitation, enabling precisely targeted drug delivery to specific brain regions. Simultaneously, it generates electrical stimulation in deep brain areas to exert synergistic neuroreparative effects. Together, these capabilities provide a more precise, efficient, and safe solution for treating neurodegenerative diseases. This review summarizes the neural regulatory mechanisms, technical advantages, and research progress of the ultrasound-responsive piezoelectric drug delivery systems for neurodegenerative disease therapy, aiming to offer novel insights for the field.
Humans ; Neurodegenerative Diseases/drug therapy* ; Drug Delivery Systems/methods* ; Blood-Brain Barrier ; Ultrasonic Waves ; Brain ; Ultrasonic Therapy ; Deep Brain Stimulation/methods*