Injectable and Self-Healing Thermosensitive Magnetic Hydrogel for Asynchronous Control Release of Doxorubicin and Docetaxel to Treat Triple-Negative Breast Cancer

Injectable and implantable hydrogels for localized delivery of drugs and nanomaterials for cancer chemotherapy: A review

Multiple chemotherapeutic strategies have been developed to tackle the complexity of cancer. Still, the outcome of chemotherapeutic regimens remains impaired by the drugs' weak solubility, unspecific biodistribution and poor tumor accumulation after systemic administration. Such constraints triggered the development of nanomaterials to encapsulate and deliver anticancer drugs. In fact, the loading of drugs into nanoparticles can overcome most of the solubility concerns. However, the ability of systemically administered drug-loaded nanomaterials to reach the tumor site has been vastly overestimated, limiting their clinical translation. The drugs' and drug-loaded nanomaterials' systemic administration issues have propelled the development of hydrogels capable of performing their direct/local delivery into the tumor site. The use of these macroscale systems to mediate a tumor-confined delivery of the drugs/drugs-loaded nanomaterials grants an improved therapeutic efficacy and, simultaneously, a reduction of the side effects. The manufacture of these hydrogels requires the careful selection and tailoring of specific polymers/materials as well as the choice of appropriate physical and/or chemical crosslinking interactions. Depending on their administration route and assembling process, these matrices can be classified as injectable in situ forming hydrogels, injectable shear-thinning/self-healing hydrogels, and implantable hydrogels, each type bringing a plethora of advantages for the intended biomedical application. This review provides the reader with an insight into the application of injectable and implantable hydrogels for performing the tumor-confined delivery of drugs and drug-loaded nanomaterials.

Hydrogel-based nanoparticles: revolutionizing brain tumor treatment and paving the way for future innovations

Brain tumor treatment remains a significant challenge due to their high mortality and resistance to current therapies. This paper discusses the promising potential of hydrogel-based nanoparticles as innovative drug delivery systems for brain tumor therapy. Extensive characterization techniques reveal the ability of these Nano-systems to demonstrate prolonged blood circulation and targeted delivery, leading to improved survival rates. Designed with optimized physicochemical characteristics, these nanoparticles effectively cross the blood-brain barrier, circumventing a major impediment to drug delivery to the brain. By delivering drugs directly to the tumor bed, these nanoparticles enhance therapeutic outcomes and minimize adverse effects. In addition, this review investigates the techniques for characterizing, visualizing, and modifying these nanoparticles, as well as the standing challenges and promising research avenues for their clinical application. Further investigations are encouraged by this review to investigate potential advancements in hydrogel-based nanoparticle therapeutic approaches for brain tumors. This includes investigating tailored hydrogels, hybrid systems, computational modeling, and the integration of gene therapy and immunotherapy techniques. The study also addresses the need for enhanced synthesis techniques, stability, scalability, and cost-cutting measures to overcome obstacles and advance the clinical use of hydrogel-based nanoparticles in treating brain tumors.

Chitosan-based hydrogels in cancer therapy: Drug and gene delivery, stimuli-responsive carriers, phototherapy and immunotherapy

Nanotechnology has transformed the oncology sector by particularly targeting cancer cells and enhancing the efficacy of conventional therapies, not only improving efficacy of conventional therapeutics, but also reducing systemic toxicity. Environmentally friendly materials are the top choice for treating cancer. Chitosan, sourced from chitin, is widely used with its derivatives for the extensive synthesis or modification of nanostructures. Chitosan has been deployed to develop hydrogels, as 3D polymeric networks capable of water absorption with wide biomedical application. The chitosan hydrogels are biocompatible and biodegradable structures that can deliver drugs, genes or a combination of them in cancer therapy. Increased tumor ablation, reducing off-targeting feature and protection of genes against degradation are benefits of using chitosan hydrogels in cancer therapy. The efficacy of cancer immunotherapy can be improved by chitosan hydrogels to prevent emergence of immune evasion. In addition, chitosan hydrogels facilitate photothermal and photodynamic therapy for tumor suppression. Chitosan hydrogels can synergistically integrate chemotherapy, immunotherapy, and phototherapy in cancer treatment. Additionally, chitosan hydrogels that respond to stimuli, specifically thermo-sensitive hydrogels, have been developed for inhibiting tumors.

Reactive Oxygen Species-Regulated Conjugates Based on Poly(jasmine) Lactone for Simultaneous Delivery of Doxorubicin and Docetaxel

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.

Double-shelled, rattle-architecture covalent organic framework: harnessing morphological manipulation for enhanced synergistic multi-drug chemo-photothermal cancer therapy

Morphological modulation in covalent organic frameworks (COFs) with particular emphasis on the correlation between structure and target applications in biomedical fields, is currently in its early stage of evolution. Herein, a multifunctional rattle-architecture imine-based COF with a mobile core of gold nanoparticles (Au NPs) and an outer polydopamine (PDA) shell, tailored for cancer treatment, has been developed to effectively integrate dual responsive release capabilities with the potential for multiple therapeutic applications. The engineered COF displays outstanding crystallinity, a suitable size and precisely controlled morphological characteristics. By leveraging COF and PDA attributes, the successful co-delivery of hydrophilic doxorubicin (DOX) and hydrophobic docetaxel (DTX) within discrete compartments is achieved responsive to both pH and near-infrared triggers. Designed nanocarrier outperforms prior COFs with a superior 83.7% DOX loading capacity, thanks to its expansive internal space and porous shell. Taking advantage of the inclusion of Au core and the concurrent presence of COF and PDA outer shells, the nanocarrier exhibits a significant photothermal-conversion capability. The rattle-architecture double-shelled Au@RCOF@PDA were functionalized with poly(ethylene glycol)-folic acid (PEG-FA) to confer the system with active-targeting capability and enhanced biocompatibility. Through in vitro and in vivo evaluations, the designed system demonstrates an exceptional synergistic anti-tumor effect, along with favorable biosafety and histocompatibility. This study not only sheds light on the remarkable merits offered by regulating the morphology of COF-based systems in cancer therapy but also highlights the potential for synergistic therapeutic approaches in advancing cancer treatment strategies.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

Injectable Nanocomposite Hydrogels Improve Intraperitoneal Co-delivery of Chemotherapeutics and Immune Checkpoint Inhibitors for Enhanced Peritoneal Metastasis Therapy

Intraperitoneal co-delivery of chemotherapeutic drugs (CDs) and immune checkpoint inhibitors (ICIs) brings hope to improve treatment outcomes in patients with peritoneal metastasis from ovarian cancer (OC). However, current intraperitoneal drug delivery systems face issues such as rapid drug clearance from lymphatic drainage, heterogeneous drug distribution, and uncontrolled release of therapeutic agents into the peritoneal cavity. Herein, we developed an injectable nanohydrogel by combining carboxymethyl chitosan (CMCS) with bioadhesive nanoparticles (BNPs) based on polylactic acid-hyperbranched polyglycerol. This system enables the codelivery of CD and ICI into the intraperitoneal space to extend drug retention. The nanohydrogel is formed by cross-linking of aldehyde groups on BNPs with amine groups on CMCS via reversible Schiff base bonds, with CD and ICI loaded separately into BNPs and CMCS network. BNP/CMCS nanohydrogel maintained the activity of the biomolecules and released drugs in a sustained manner over a 7 day period. The adhesive property, through the formation of Schiff bases with peritoneal tissues, confers BNPs with an extended residence time in the peritoneal cavity after being released from the nanohydrogel. In a mouse model, BNP/CMCS nanohydrogel loaded with paclitaxel (PTX) and anti-PD-1 antibodies (αPD-1) significantly suppressed peritoneal metastasis of OC compared to all other tested groups. In addition, no systemic toxicity of nanohydrogel-loaded PTX and αPD-1 was observed during the treatment, which supports potential translational applications of this delivery system.

Injectable Hydrogels: A Paradigm Tailored with Design, Characterization, and Multifaceted Approaches

Biomaterials denoting self-healing and versatile structural integrity are highly curious in the biomedicine segment. The injectable and/or printable 3D printing technology is explored in a few decades back, which can alter their dimensions temporarily under shear stress, showing potential healing/recovery tendency with patient-specific intervention toward the development of personalized medicine. Thus, self-healing injectable hydrogels (IHs) are stunning toward developing a paradigm for tissue regeneration. This review comprises the designing of IHs, rheological characterization and stability, several benchmark consequences for self-healing IHs, their translation into tissue regeneration of specific types, applications of IHs in biomedical such as anticancer and immunomodulation, wound healing and tissue/bone regeneration, antimicrobial potentials, drugs, gene and vaccine delivery, ocular delivery, 3D printing, cosmeceuticals, and photothermal therapy as well as in other allied avenues like agriculture, aerospace, electronic/electrical industries, coating approaches, patents associated with therapeutic/nontherapeutic avenues, and numerous futuristic challenges and solutions.

Metal organic framework-based polymeric hydrogel: A promising drug delivery vehicle for the treatment of breast cancer

The constraints associated with current cancer therapies have inspired scientists to develop advanced, precise, and safe drug delivery methods. These delivery systems boost treatment effectiveness, minimize harm to healthy cells, and combat cancer recurrence. To design advanced drug delivery vehicle with these character, in the present manuscript, we have designed a self-healing and injectable hybrid hydrogel through synergistically interacting metal organic framework, CuBTC with the poly(vinyl alcohol) (PVA). This hybrid hydrogel acts as a localized drug delivery system and was used to encapsulate and release the anticancer drug 5-Fluorouracil selectively at the targeted site in response to the physiological pH. The hydrogel was formed through transforming the gaussian coil like matrix of PVA-CuBTC into a three-dimensional network of hydrogel upon the addition of crosslinker; borax. The biocompatible character of the hydrogel was confirmed through cell viability test. The biocompatible hybrid hydrogel then was used to encapsulate and studied for the pH responsive release behavior of the anti-cancer drug, 5-FU. The in vitro cytotoxicity of the drug-loaded hydrogel was evaluated against MCF-7 and HeLa cells. The study confirms that the hybrid hydrogel is effective for targeted and sustained release of anticancer drugs at cancer sites.

Chemical and Photochemical-Driven Dissipative Fe3+/Fe2+-Ion Cross-Linked Carboxymethyl Cellulose Gels Operating Under Aerobic Conditions: Applications for Transient Controlled Release and Mechanical Actuation

A Fe3+-ion cross-linked carboxymethyl cellulose, Fe3+-CMC, redox-active gel exhibiting dissipative, transient stiffness properties is introduced. Chemical or photosensitized reduction of the higher-stiffness Fe3+-CMC to the lower-stiffness Fe2+-CMC gel, accompanied by the aerobic reoxidation of the Fe2+-CMC matrix, leads to the dissipative, transient stiffness, functional matrix. The light-induced, temporal, transient release of a load (Texas red dextran) and the light-triggered, transient mechanical bending of a poly-N-isopropylacrylamide (p-NIPAM)/Fe3+-CMC bilayer construct are introduced, thus demonstrating the potential use of the dissipative Fe3+-CMC gel for controlled drug release or soft robotic applications.

Composite Microparticles from Microfluidics for Chemo-/Photothermal Therapy of Hepatocellular Carcinoma

Hydrogel microcarrier-based drug delivery systems are of great value in the combination therapy of tumors. Current research directions concentrate on the development of more economic, convenient, and effective combined therapeutic platforms. Herein, we developed novel adhesive composite microparticles (MPPMD) with combined chemo- and photothermal therapy ability via microfluidic electrospray technology for local hepatocellular carcinoma treatment. These composite microparticles consisted of doxorubicin (DOX)-loaded and polydopamine-wrapped mesoporous silicon and alginate. Benefiting from such a strategy of hierarchical structure drug loading, DOX could be gradually released from the system, effectively avoiding the direct toxicity of chemotherapeutics to the body. Additionally, the designed microparticles could not only effectively treat tumors by releasing the chemotherapy drug DOX but also show excellent photothermal properties under the irradiation of near-infrared light, achieving combined chemo- and photothermal treatment effects. Based on these advantages, the MPPMD could remarkably eliminate tumor cells in vitro and enormously restrict tumor development in vivo. These results illustrate that such composite microparticles are ideal combination treatment platforms, possessing promising expectations for cancer therapy.

Stimuli-responsive hydrogel based on natural polymers for breast cancer

Aims: Breast cancer is the most common malignancy among women in both high- and low-resource settings. Conventional breast cancer therapies were inefficient and had low patient compliance. Stimuli-responsive hydrogels possessing similar physicochemical features as soft tissue facilitate diagnostic and therapeutic approaches for breast cancer subtypes. Scope: Polysaccharides and polypeptides are major natural polymers with unique biocompatibility, biodegradability, and feasible modification approaches utilized frequently for hydrogel fabrication. Alternating the natural polymer-based hydrogel properties in response to external stimuli such as pH, temperature, light, ultrasonic, enzyme, glucose, magnetic, redox, and electric have provided great potential for the evolution of novel drug delivery systems (DDSs) and various advanced technologies in medical applications. Stimuli-responsive hydrogels are triggered by specific cancer tissue features, promote target delivery techniques, and modify release therapeutic agents at localized sites. This narrative review presented innovation in preparing and characterizing the most common stimuli-responsive natural polymer-based hydrogels for diagnostic and therapeutic applications in the breast cancer area. Conclusion: Stimuli-responsive hydrogels display bioinspiration products as DDSs for breast cancer subtypes, protect the shape of breast tissue, provide modified drug release, enhance therapeutic efficacy, and minimize chemotherapy agents' side effects. The potential benefits of smart natural polymer-based hydrogels make them an exciting area of practice for breast cancer diagnosis and treatment.

Polymeric Micelle-Based Nanogels as Emerging Drug Delivery Systems in Breast Cancer Treatment: Promises and Challenges

Breast cancer is a pervasive global health issue that disproportionately impacts the female population. Over the past few years, there has been considerable interest in nanotechnology due to its potential utility in creating drug-delivery systems designed to combat this illness. The primary aim of these devices is to enhance the delivery of targeted medications, optimise the specific cells that receive the drugs, tackle treatment resistance in malignant cells, and introduce novel strategies for preventing and controlling diseases. This research aims to examine the methodologies utilised by various carrier nanoparticles in the context of therapeutic interventions for breast cancer. The main objective is to investigate the potential application of novel delivery technologies to attain timely and efficient diagnosis and treatment. Current cancer research predominantly examines diverse drug delivery methodologies for chemotherapeutic agents. These methodologies encompass the development of hydrogels, micelles, exosomes, and similar compounds. This research aims to analyse the attributes, intricacies, notable advancements, and practical applications of the system in clinical settings. Despite the demonstrated efficacy of these methodologies, an apparent discrepancy can be observed between the progress made in developing innovative therapeutic approaches and their widespread implementation in clinical settings. It is critical to establish a robust correlation between these two variables to enhance the effectiveness of medication delivery systems based on nanotechnology in the context of breast cancer treatment.

Architecturally designed sequential-release hydrogels

Drug synergy has made significant strides in clinical applications in recent decades. However, achieving a platform that enables "single administration, multi-stage release" by emulating the natural physiological processes of the human body poses a formidable challenge in the field of molecular pharmaceutics. Hydrogels, as the novel generation of drug delivery systems, have gained widespread utilization in drug platforms owing to their exceptional biocompatibility and modifiability. Sequential drug delivery hydrogels (SDDHs), which amalgamate the advantages of hydrogel and sequential release platforms, offer a promising solution for effectively navigating the intricate human environment and accomplishing drug sequential release. Inspired by architectural design, this review establishes connections between three pivotal factors in SDDHs construction, namely mechanisms, carrier spatial structure, and stimuli-responsiveness, and three aspects of architectural design, specifically building materials, house structures, and intelligent interactive furniture, aiming at providing insights into recent developments in SDDHs. Furthermore, the dual-drug collocation and cutting-edge hydrogel preparation technologies as well as the prevailing challenges in the field were elucidated.

Antibacterial Hydrogel as a Self-Drug-Delivery System Derived from Zn(II)-bis-imidazole/NSAID-Based Organic-Inorganic Hybrids

A skin wound is prone to bacterial infection and growth. An antibacterial topical hydrogel that can act as a self-drug-delivery (SDD) system is reported here. Two bidentate ligands (L2/L1) derived from imidazole/benzimidazole derivatives when reacted with Zn(NO3)2 and a series of nonsteroidal-anti-inflammatory drugs (NSAIDs) produced crystalline products, which were characterized by single-crystal X-ray diffraction (SXRD). Simple mixing of the ingredients of the crystalline products (stoichiometry guided by the corresponding crystal structure) produced an aqueous gel (DMSO/water) when the bidentate ligand was water-insoluble L2, whereas water-soluble L1 readily produced hydrogels under similar conditions. Dynamic rheology and scanning electron microscopy (SEM) were employed to characterize the gels. Zone inhibition diameters, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and hemolysis data suggested that among the hydrogelators, L1MEC derived from L1, meclofenac and Zn(NO3)2, was found to be the best against the Gram-negative bacteria Escherichia coli. The corresponding hydrogel L1MEC_HG and a piece of a dried cloth bandage coated with the hydrogel also showed appreciable activity against E. coli. The antibacterial property of L1MEC_HG against E. coli, thus demonstrated, is relevant in developing an antibacterial SDD system because E. coli is reported to be present in infected wounds.

Advances in Doxorubicin-based nano-drug delivery system in triple negative breast cancer

Triple positive breast cancer (TPBC) is one of the most aggressive breast cancer. Due to the unique cell phenotype, aggressiveness, metastatic potential and lack of receptors or targets, chemotherapy is the choice of treatment for TNBC. Doxorubicin (DOX), one of the representative agents of anthracycline chemotherapy, has better efficacy in patients with metastatic TNBC (mTNBC). DOX in anthracycline-based chemotherapy regimens have higher response rates. Nano-drug delivery systems possess unique targeting and ability of co-load, deliver and release chemotherapeutic drugs, active gene fragments and immune enhancing factors to effectively inhibit or kill tumor cells. Therefore, advances in nano-drug delivery systems for DOX therapy have attracted a considerable amount of attention from researchers. In this article, we have reviewed the progress of nano-drug delivery systems (e.g., Nanoparticles, Liposomes, Micelles, Nanogels, Dendrimers, Exosomes, etc.) applied to DOX in the treatment of TNBC. We also summarize the current progress of clinical trials of DOX combined with immune checkpoint inhibitors (ICIS) for the treatment of TNBC. The merits, demerits and future development of nanomedicine delivery systems in the treatment of TNBC are also envisioned, with the aim of providing a new class of safe and efficient thoughts for the treatment of TNBC.

Injectable hydrogels for the delivery of nanomaterials for cancer combinatorial photothermal therapy

Progress in the nanotechnology field has led to the development of a new class of materials capable of producing a temperature increase triggered by near infrared light. These photothermal nanostructures have been extensively explored in the ablation of cancer cells. Nevertheless, the available data in the literature have exposed that systemically administered nanomaterials have a poor tumor-homing capacity, hindering their full therapeutic potential. This paradigm shift has propelled the development of new injectable hydrogels for the local delivery of nanomaterials aimed at cancer photothermal therapy. These hydrogels can be assembled at the tumor site after injection (in situ forming) or can undergo a gel-sol-gel transition during injection (shear-thinning/self-healing). Besides incorporating photothermal nanostructures, these injectable hydrogels can also incorporate or be combined with other agents, paving the way for an improved therapeutic outcome. This review analyses the application of injectable hydrogels for the local delivery of nanomaterials aimed at cancer photothermal therapy as well as their combination with photodynamic-, chemo-, immuno- and radio-therapies.

Injectable Hydrogels of Amphiphilic Vitamin E Derivatives for Locoregional Chemotherapy

Vitamin E derivatives are particularly effective in chemotherapy drug development because they are nontoxic, biocompatible, and selective. Among them, α-tocopheryl succinate (α-TOS) can act synergistically with some chemotherapeutic agents. However, its hydrophobicity limits its systemic administration, and localized formulations are not available. Herein, we developed an injectable hydrogel based on self-assembled micelles of a triblock amphiphilic derivative of α-TOS (PEG-2VES), in which doxorubicin (DOX) was encapsulated in the core of the micelles for combined chemotherapy. A molecule of α-TOS was grafted onto each end of poly(ethylene glycols) (PEGs) of different lengths. Hydrogels were prepared by dissolving the polymers or the DOX-loaded micelles in water at room temperature. The subcutaneously injected hydrogels kept their shape and sustainably released the payloads over 7 days without any noticeable inflammatory response. In vitro and in vivo results confirmed the synergistic antitumor effects of the hydrogel and loaded drug. Furthermore, DOX-loaded hydrogels showed greater therapeutic efficiency and fewer toxic side effects than DOX alone. Overall, this hydrogel acts as a multifunctional system that can deliver drug, improve the therapeutic effect, and minimize drug toxicity.

Stimuli-Responsive DNA-Based Hydrogels on Surfaces for Switchable Bioelectrocatalysis and Controlled Release of Loads

The assembly of enzyme [glucose oxidase (GOx)]-loaded stimuli-responsive DNA-based hydrogels on electrode surfaces, and the triggered control over the stiffness of the hydrogels, provides a means to switch the bioelectrocatalytic functions of the hydrogels. One system includes the assembly of GOx-loaded, pH-responsive, hydrogel matrices cross-linked by two cooperative nucleic acid motives comprising permanent duplex nucleic acids and "caged" i-motif pH-responsive duplexes. Bioelectrocatalyzed oxidation of glucose leads to the formation of gluconic acid that acidifies the hydrogel resulting in the separation of the i-motif constituents and lowering the hydrogel stiffness. Loading of the hydrogel matrices with insulin results in the potential-triggered, glucose concentration-controlled, switchable release of insulin from the hydrogel-modified electrodes. The switchable bioelectrocatalyzed release of insulin is demonstrated in the presence of ferrocenemethanol as a diffusional electron mediator or by applying an electrically wired integrated matrix that includes ferrocenyl-modified GOx embedded in the hydrogel. The second GOx-loaded, stimuli-responsive, DNA-based hydrogel matrix associated with the electrode includes a polyacrylamide hydrogel cooperatively cross-linked by duplex nucleic acids and "caged" G-quadruplex-responsive duplexes. The hydrogel matrix undergoes K+-ions/crown ether-triggered stiffness changes by the cyclic K+-ion-stimulated formation of G-quadruplexes (lower stiffness) and the crown ether-induced separation of the G-quadruplexes (higher stiffness). The hydrogel matrices demonstrate switchable bioelectrocatalytic functions guided by the stiffness properties of the hydrogels.

Nanoplatforms: The future of oral cancer treatment

Background and Aims

Cytotoxicity is a key disadvantage of using chemotherapeutic drugs to treat cancer. This can be overcome by encapsulating chemotherapeutic drugs in suitable carriers for targeted delivery, allowing them to be released only at the cancerous sites. Herein, we aim to review the recent scientific developments in the utilization of nanotechnology-based drug delivery systems for treating oral malignancies that can lead to further improvements in clinical practice.

Methods

A comprehensive literature search was conducted on PubMed, Google Scholar, ScienceDirect, and other notable databases to identify recent peer-reviewed clinical trials, reviews, and research articles related to nanoplatforms and their applications in oral cancer treatment.

Results

Nanoplatforms offer a revolutionary strategy to overcome the challenges associated with conventional oral cancer treatments, such as poor drug solubility, non-specific targeting, and systemic toxicity. These nanoscale drug delivery systems encompass various formulations, including liposomes, polymeric nanoparticles, dendrimers, and hydrogels, which facilitate controlled release and targeted delivery of therapeutic agents to oral cancer sites. By exploiting the enhanced permeability and retention effect, Nanoplatforms accumulate preferentially in the tumor microenvironment, increasing drug concentration and minimizing damage to healthy tissues. Additionally, nanoplatforms can be engineered to carry multiple drugs or a combination of drugs and diagnostic agents, enabling personalized and precise treatment approaches.

Conclusion

The utilization of nanoplatforms in oral cancer treatment holds significant promise in revolutionizing therapeutic strategies. Despite the promising results in preclinical studies, further research is required to evaluate the safety, efficacy, and long-term effects of nanoformulations in clinical settings. If successfully translated into clinical practice, nanoplatform-based therapies have the potential to improve patient outcomes, reduce side effects, and pave the way for more personalized and effective oral cancer treatments.

Poly Ethylene Glycol (PEG)-Based Hydrogels for Drug Delivery in Cancer Therapy: A Comprehensive Review

Hydrogel-based drug delivery systems (DDSs) can leverage therapeutically beneficial outcomes in cancer therapy. In this domain, polyethylene glycol (PEG) has become increasingly popular as a biomedical polymer and has found clinical use. Owing to their excellent biocompatibility, facile modifiability, and high drug encapsulation rate, PEG hydrogels have shown great promise as drug delivery platforms. Here, the progress in emerging novel designs of PEG-hydrogels as DDSs for anti-cancer therapy is reviewed and discussed, focusing on underpinning multiscale release mechanisms categorized under stimuli-responsive and non-responsive drug release. The responsive drug delivery approaches are discussed, and the underpinning release mechanisms are elucidated, covering the systems functioning based on either exogenous stimuli-response, such as photo- and magnetic-sensitive PEG hydrogels, or endogenous stimuli-response, such as enzyme-, pH-, reduction-, and temperature-sensitive PEG hydrogels. Special attention is paid to the commercial potential of PEG-based hydrogels in cancer therapy, highlighting the limitations that need to be addressed in future research for their clinical translation.

External magnetic field non-invasively stimulates spinal cord regeneration in rat via a magnetic-responsive aligned fibrin hydrogel

Magnetic stimulation is becoming an attractive approach to promote neuroprotection, neurogenesis, axonal regeneration, and functional recovery in both the central nervous system and peripheral nervous system disorders owing to its painless, non-invasive, and deep penetration characteristics. Here, a magnetic-responsive aligned fibrin hydrogel (MAFG) was developed to import and amplify the extrinsic magnetic field (MF) locally to stimulate spinal cord regeneration in combination with the beneficial topographical and biochemical cues of aligned fibrin hydrogel (AFG). Magnetic nanoparticles (MNPs) were embedded uniformly in AFG during electrospinning to endow it magnetic-responsive feature, with saturation magnetization of 21.79 emu g-1. It is found that the MNPs under the MF could enhance cell proliferation and neurotrophin secretion of PC12 cellsin vitro. The MAFG that was implanted into a rat with 2 mm complete transected spinal cord injury (SCI) effectively enhanced neural regeneration and angiogenesis in the lesion area, thus leading to significant recovery of motor function under the MF (MAFG@MF). This study suggests a new multimodal tissue engineering strategy based on multifunctional biomaterials that deliver multimodal regulatory signals with the integration of aligned topography, biochemical cues, and extrinsic MF stimulation for spinal cord regeneration following severe SCI.

Injectable nano-composite hydrogels based on hyaluronic acid-chitosan derivatives for simultaneous photothermal-chemo therapy of cancer with anti-inflammatory capacity

Nowadays, the photothermal therapy (PTT) has received widespread attention and research by rapidly killing tumors with local high temperature. However, due to the irregular edges of tumor and the blurred boundary between normal and necrotic tissues, the desirable treatment cannot be achieved by the single PTT, and excessive heat will cause serious inflammation in local tissues. Herein, an injectable composite hydrogel is prepared by the oxidized hyaluronic acid (OHA) and hydroxypropyl chitosan (HPCS) via the imine bonds, which is employed as the delivery substrate for functional substances. In the gel medium, the mesoporous polydopamine (MPDA) nanoparticles are incorporated as the high efficiency photothermal agent and a reservoir of DOX, which can achieve the good photothermal conversion performance and pulsed drug release. Besides, the addition of the curcumin-cyclodextrin host-guest inclusion complex (CUR@NH₂-CD) in the composite hydrogel could reduce the inflammation caused by PTT. The composite hydrogel shows favorable the Hepa1-6 tumor inhibition in vivo by virtue of the comprehensive effect of the admired photothermal efficacy of MPDA, chemotherapy of DOX and anti-inflammatory of CUR. It can be predicted that the composite hydrogel has a broad prospect in the field of comprehensive therapy for tumor.

Nanoarchitecture-Integrated Hydrogel Systems toward Therapeutic Applications

Hydrogels, as one of the most feasible soft biomaterials, have gained considerable attention in therapeutic applications by virtue of their tunable properties including superior patient compliance, good biocompatibility and biodegradation, and high cargo-loading efficiency. However, hydrogel application is still limited by some challenges like inefficient encapsulation, easy leakage of loaded cargoes, and the lack of controllability. Recently, nanoarchitecture-integrated hydrogel systems were found to be therapeutics with optimized properties, extending their bioapplication. In this review, we briefly presented the category of hydrogels according to their synthetic materials and further discussed the advantages in bioapplication. Additionally, various applications of nanoarchitecture hybrid hydrogels in biomedical engineering are systematically summarized, including cancer therapy, wound healing, cardiac repair, bone regeneration, diabetes therapy, and obesity therapy. Last, the current challenges, limitations, and future perspectives in the future development of nanoarchitecture-integrated flexible hydrogels are addressed.

Iron Oxide@Mesoporous Silica Core-Shell Nanoparticles as Multimodal Platforms for Magnetic Resonance Imaging, Magnetic Hyperthermia, Near-Infrared Light Photothermia, and Drug Delivery

The design of core-shell nanocomposites composed of an iron oxide core and a silica shell offers promising applications in the nanomedicine field, especially for developing efficient theranostic systems which may be useful for cancer treatments. This review article addresses the different ways to build iron oxide@silica core-shell nanoparticles and it reviews their properties and developments for hyperthermia therapies (magnetically or light-induced), combined with drug delivery and MRI imaging. It also highlights the various challenges encountered, such as the issues associated with in vivo injection in terms of NP-cell interactions or the control of the heat dissipation from the core of the NP to the external environment at the macro or nanoscale.

Dual-Stimuli-Sensitive Smart Hydrogels Containing Magnetic Nanoparticles as Antitumor Local Drug Delivery Systems-Synthesis and Characterization

The aim of this study was to develop an innovative, dual-stimuli-responsive smart hydrogel local drug delivery system (LDDS), potentially useful as an injectable simultaneous chemotherapy and magnetic hyperthermia (MHT) antitumor treatment device. The hydrogels were based on a biocompatible and biodegradable poly(ε-caprolactone-co-rac-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-rac-lactide) (PCLA-PEG-PCLA, PCLA) triblock copolymer, synthesized via ring-opening polymerization (ROP) in the presence of a zirconium(IV) acetylacetonate (Zr(acac)4) catalyst. The PCLA copolymers were successfully synthesized and characterized using NMR and GPC techniques. Furthermore, the gel-forming and rheological properties of the resulting hydrogels were thoroughly investigated, and the optimal synthesis conditions were determined. The coprecipitation method was applied to create magnetic iron oxide nanoparticles (MIONs) with a low diameter and a narrow size distribution. The magnetic properties of the MIONs were close to superparamagnetic upon TEM, DLS, and VSM analysis. The particle suspension placed in an alternating magnetic field (AMF) of the appropriate parameters showed a rapid increase in temperature to the values desired for hyperthermia. The MIONs/hydrogel matrices were evaluated for paclitaxel (PTX) release in vitro. The release was prolonged and well controlled, displaying close to zero-order kinetics; the drug release mechanism was found to be anomalous. Furthermore, it was found that the simulated hyperthermia conditions had no effect on the release kinetics. As a result, the synthesized smart hydrogels were discovered to be a promising antitumor LDDS, allowing simultaneous chemotherapy and hyperthermia treatment.

A Review of Advanced Multifunctional Magnetic Nanostructures for Cancer Diagnosis and Therapy Integrated into an Artificial Intelligence Approach

The new era of nanomedicine offers significant opportunities for cancer diagnostics and treatment. Magnetic nanoplatforms could be highly effective tools for cancer diagnosis and treatment in the future. Due to their tunable morphologies and superior properties, multifunctional magnetic nanomaterials and their hybrid nanostructures can be designed as specific carriers of drugs, imaging agents, and magnetic theranostics. Multifunctional magnetic nanostructures are promising theranostic agents due to their ability to diagnose and combine therapies. This review provides a comprehensive overview of the development of advanced multifunctional magnetic nanostructures combining magnetic and optical properties, providing photoresponsive magnetic platforms for promising medical applications. Moreover, this review discusses various innovative developments using multifunctional magnetic nanostructures, including drug delivery, cancer treatment, tumor-specific ligands that deliver chemotherapeutics or hormonal agents, magnetic resonance imaging, and tissue engineering. Additionally, artificial intelligence (AI) can be used to optimize material properties in cancer diagnosis and treatment, based on predicted interactions with drugs, cell membranes, vasculature, biological fluid, and the immune system to enhance the effectiveness of therapeutic agents. Furthermore, this review provides an overview of AI approaches used to assess the practical utility of multifunctional magnetic nanostructures for cancer diagnosis and treatment. Finally, the review presents the current knowledge and perspectives on hybrid magnetic systems as cancer treatment tools with AI models.

Promising Delivery Platform for Smart Pest Control with High Water-Retaining Capacity

Hydrogels have been extensively used in agriculture to improve crop yields for their excellent properties. However, they are currently used either as pesticide delivery platforms or water retention agents alone; the combination of these two functions into one agricultural hydrogel formulation has never been reported, which is crucial to promote sustainable development in agriculture. Herein, using poly(β-cyclodextrin) and adamantane-grafted poly(acrylic acid) (PAA-Ada) as the host and guest, respectively, an easy operating, multi-responsive, and safer hydrogel delivery system for insecticides is fabricated by the host-guest interaction between cyclodextrin and adamantane, which can load uniformly dispersed insecticides (fipronil, imidacloprid, and thiamethoxam) up to 60%. Benefiting from the carboxyl and hydroxyl groups on polymer chains, different temperatures (25, 35, and 45 °C) and pH values (5.0, 6.8, and 10.0) change the intermolecular forces within the hydrogel network and then the diffusion of the content, finally resulting in controlled release behaviors. Besides, this platform can rapidly release the insecticides in the presence of amyloglucosidase due to its ring-opening effect on cyclodextrin. Moreover, this platform exhibits high water-retaining capacity toward soil, which can increase the maximum water absorption of nutrient soil and quartz sand by 31.6 and 13.9%, respectively, and slows down the water loss. Compared with commercial formulation, this smart system reduces the acute toxicity to non-target organism earthworms by 52.4% and improves the efficacy against target organism aphids by 47.3%, showing better durability, lower environmental toxicity, and higher efficiency. To our knowledge, this is the first idea that simultaneously adopts the water-retaining capacity and controlled release ability of hydrogels to improve insecticide efficacy. In this regard, this smart hydrogel platform holds great potentials as slow-release granules with water-holding ability for protection against insect pests, providing an alternative platform for the sustainable development in green agriculture.

Advances in Polymeric Colloids for Cancer Treatment

Polymer colloids have remarkable features and are gaining importance in many areas of research including medicinal science. Presently, the innovation of cancer drugs is at the top in the world. Polymer colloids have been used as drug delivery and diagnosis agents in cancer treatment. The polymer colloids may be of different types such as micelles, liposomes, emulsions, cationic carriers, and hydrogels. The current article describes the state-of-the-art polymer colloids for the treatment of cancer. The contents of this article are about the role of polymeric nanomaterials with special emphasis on the different types of colloidal materials and their applications in targeted cancer therapy including cancer diagnoses. In addition, attempts are made to discuss future perspectives. This article will be useful for academics, researchers, and regulatory authorities.

Flexible polymeric patch based nanotherapeutics against non-cancer therapy

Flexible polymeric patches find widespread applications in biomedicine because of their biological and tunable features including excellent patient compliance, superior biocompatibility and biodegradation, as well as high loading capability and permeability of drug. Such polymeric patches are classified into microneedles (MNs), hydrogel, microcapsule, microsphere and fiber depending on the formed morphology. The combination of nanomaterials with polymeric patches allows for improved advantages of increased curative efficacy and lowered systemic toxicity, promoting on-demand and regulated drug administration, thus providing the great potential to their clinic translation. In this review, the category of flexible polymeric patches that are utilized to integrate with nanomaterials is briefly presented and their advantages in bioapplications are further discussed. The applications of nanomaterials embedded polymeric patches in non-cancerous diseases were also systematically reviewed, including diabetes therapy, wound healing, dermatological disease therapy, bone regeneration, cardiac repair, hair repair, obesity therapy and some immune disease therapy. Alternatively, the limitations, latest challenges and future perspectives of such biomedical therapeutic devices are addressed.

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The most explored polymeric patches, such as microneedle, hydrogel, microsphere, microcapsule, and fiber are summarized.

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Polymeric patches integrated with a diversity of nanomaterials are systematically overviewed in non-cancer therapy.

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The future prospective for the development of polymeric patch based nanotherapeutics is discussed.

Recent advances in responsive hydrogels for diabetic wound healing

Poor wound healing after diabetes mellitus remains a challenging problem, and its pathophysiological mechanisms have not yet been fully elucidated. Persistent bleeding, disturbed regulation of inflammation, blocked cell proliferation, susceptible infection and impaired tissue remodeling are the main features of diabetic wound healing. Conventional wound dressings, including gauze, films and bandages, have a limited function. They generally act as physical barriers and absorbers of exudates, which fail to meet the requirements of the whol diabetic wound healing process. Wounds in diabetic patients typically heal slowly and are susceptible to infection due to hyperglycemia within the wound bed. Once bacterial cells develop into biofilms, diabetic wounds will exhibit robust drug resistance. Recently, the application of stimuli-responsive hydrogels, also known as "smart hydrogels", for diabetic wound healing has attracted particular attention. The basic feature of this system is its capacities to change mechanical properties, swelling ability, hydrophilicity, permeability of biologically active molecules, etc., in response to various stimuli, including temperature, potential of hydrogen (pH), protease and other biological factors. Smart hydrogels can improve therapeutic efficacy and limit total toxicity according to the characteristics of diabetic wounds. In this review, we summarized the mechanism and application of stimuli-responsive hydrogels for diabetic wound healing. It is hoped that this work will provide some inspiration and suggestions for research in this field.

Photonic and magnetic materials for on-demand local drug delivery

Nanomedicine has been considered a promising tool for biomedical research and clinical practice in the 21st century because of the great impact nanomaterials could have on human health. The generation of new smart nanomaterials, which enable time- and space-controlled drug delivery, improve the limitations of conventional treatments, such as non-specific targeting, poor biodistribution and permeability. These smart nanomaterials can respond to internal biological stimuli (pH, enzyme expression and redox potential) and/or external stimuli (such as temperature, ultrasound, magnetic field and light) to further the precision of therapies. To this end, photonic and magnetic nanoparticles, such as gold, silver and iron oxide, have been used to increase sensitivity and responsiveness to external stimuli. In this review, we aim to report the main and most recent systems that involve photonic or magnetic nanomaterials for external stimulus-responsive drug release. The uniqueness of this review lies in highlighting the versatility of integrating these materials within different carriers. This leads to enhanced performance in terms of in vitro and in vivo efficacy, stability and toxicity. We also point out the current regulatory challenges for the translation of these systems from the bench to the bedside, as well as the yet unresolved matter regarding the standardization of these materials.

Dual Inhibition of BRAF-MAPK and STAT3 Signaling Pathways in Resveratrol-Suppressed Anaplastic Thyroid Cancer Cells with BRAF Mutations

Anaplastic thyroid cancer is an extremely lethal malignancy without reliable treatment. BRAFV600E point mutation is common in ATCs, which leads to MAPK signaling activation and is regarded as a therapeutic target. Resveratrol inhibits ATC cell growth, while its impact on BRAF-MAPK signaling remains unknown. This study aims to address this issue by elucidating the statuses of BRAF-MAPK and STAT3 signaling activities in resveratrol-treated THJ-11T, THJ-16T, and THJ-21T ATC cells and Nthyori 3-1 thyroid epithelial cells. RT-PCR and Sanger sequencing revealed MKRN1-BRAF fusion mutation in THJ-16T, BRAF V600E point mutation in THJ-21T, and wild-type BRAF genes in THJ-11T and Nthyori 3-1 cells. Western blotting and immunocytochemical staining showed elevated pBRAF, pMEK, and pERK levels in THJ-16T and THJ-21T, but not in THJ-11T or Nthyori 3-1 cells. Calcein/PI, EdU, and TUNEL assays showed that compared with docetaxel and doxorubicin and MAPK-targeting dabrafenib and trametinib, resveratrol exerted more powerful inhibitory effects on mutant BRAF-harboring THJ-16T and THJ-21T cells, accompanied by reduced levels of MAPK pathway-associated proteins and pSTAT3. Trametinib- and dabrafenib-enhanced STAT3 activation was efficiently suppressed by resveratrol. In conclusion, resveratrol acts as dual BRAF-MAPK and STAT3 signaling inhibitor and a promising agent against ATCs with BRAF mutation.

4D Printing of Hydrogels: Innovation in Material Design and Emerging Smart Systems for Drug Delivery

Advancements in the material design of smart hydrogels have transformed the way therapeutic agents are encapsulated and released in biological environments. On the other hand, the expeditious development of 3D printing technologies has revolutionized the fabrication of hydrogel systems for biomedical applications. By combining these two aspects, 4D printing (i.e., 3D printing of smart hydrogels) has emerged as a new promising platform for the development of novel controlled drug delivery systems that can adapt and mimic natural physio-mechanical changes over time. This allows printed objects to transform from static to dynamic in response to various physiological and chemical interactions, meeting the needs of the healthcare industry. In this review, we provide an overview of innovation in material design for smart hydrogel systems, current technical approaches toward 4D printing, and emerging 4D printed novel structures for drug delivery applications. Finally, we discuss the existing challenges in 4D printing hydrogels for drug delivery and their prospects.

Customizing nano-chitosan for sustainable drug delivery

Chitosan is a natural polymer with acceptable biocompatibility, biodegradability, and mechanical stability; hence, it has been widely appraised for drug and gene delivery applications. However, there has been no comprehensive assessment to tailor-make chitosan cross-linkers of various types and functionalities as well as complex chitosan-based semi- and full-interpenetrating networks for drug delivery systems (DDSs). Herein, various fabrication methods developed for chitosan hydrogels are deliberated, including chitosan crosslinking with and without diverse cross-linkers. Tripolyphosphate, genipin and multi-functional aldehydes, carboxylic acids, and epoxides are common cross-linkers used in developing biomedical chitosan for DDSs. Methods deployed for modifying the properties and performance of chitosan hydrogels, via their composite production (semi- and full-interpenetrating networks), are also cogitated here. In addition, recent advances in the fabrication of advanced chitosan hydrogels for drug delivery applications such as oral drug delivery, transdermal drug delivery, and cancer therapy are discussed. Lastly, thoughts on what is needed for the chitosan field to continue to grow is also debated in this comprehensive review article.

Self-Healing Injectable Hydrogels for Tissue Regeneration

Biomaterials with the ability to self-heal and recover their structural integrity offer many advantages for applications in biomedicine. The past decade has witnessed the rapid emergence of a new class of self-healing biomaterials commonly termed injectable, or printable in the context of 3D printing. These self-healing injectable biomaterials, mostly hydrogels and other soft condensed matter based on reversible chemistry, are able to temporarily fluidize under shear stress and subsequently recover their original mechanical properties. Self-healing injectable hydrogels offer distinct advantages compared to traditional biomaterials. Most notably, they can be administered in a locally targeted and minimally invasive manner through a narrow syringe without the need for invasive surgery. Their moldability allows for a patient-specific intervention and shows great prospects for personalized medicine. Injected hydrogels can facilitate tissue regeneration in multiple ways owing to their viscoelastic and diffusive nature, ranging from simple mechanical support, spatiotemporally controlled delivery of cells or therapeutics, to local recruitment and modulation of host cells to promote tissue regeneration. Consequently, self-healing injectable hydrogels have been at the forefront of many cutting-edge tissue regeneration strategies. This study provides a critical review of the current state of self-healing injectable hydrogels for tissue regeneration. As key challenges toward further maturation of this exciting research field, we identify (i) the trade-off between the self-healing and injectability of hydrogels vs their physical stability, (ii) the lack of consensus on rheological characterization and quantitative benchmarks for self-healing injectable hydrogels, particularly regarding the capillary flow in syringes, and (iii) practical limitations regarding translation toward therapeutically effective formulations for regeneration of specific tissues. Hence, here we (i) review chemical and physical design strategies for self-healing injectable hydrogels, (ii) provide a practical guide for their rheological analysis, and (iii) showcase their applicability for regeneration of various tissues and 3D printing of complex tissues and organoids.

Magnetic Self-Healing Composites: Synthesis and Applications

Magnetic composites and self-healing materials have been drawing much attention in their respective fields of application. Magnetic fillers enable changes in the material properties of objects, in the shapes and structures of objects, and ultimately in the motion and actuation of objects in response to the application of an external field. Self-healing materials possess the ability to repair incurred damage and consequently recover the functional properties during healing. The combination of these two unique features results in important advances in both fields. First, the self-healing ability enables the recovery of the magnetic properties of magnetic composites and structures to extend their service lifetimes in applications such as robotics and biomedicine. Second, magnetic (nano)particles offer many opportunities to improve the healing performance of the resulting self-healing magnetic composites. Magnetic fillers are used for the remote activation of thermal healing through inductive heating and for the closure of large damage by applying an alternating or constant external magnetic field, respectively. Furthermore, hard magnetic particles can be used to permanently magnetize self-healing composites to autonomously re-join severed parts. This paper reviews the synthesis, processing and manufacturing of magnetic self-healing composites for applications in health, robotic actuation, flexible electronics, and many more.

Nanoscale bioconjugates: A review of the structural attributes of drug-loaded nanocarrier conjugates for selective cancer therapy

Nanobioconjugates are nanoscale drug delivery vehicles that have been conjugated to or decorated with biologically active targeting ligands. These targeting ligands can be antibodies, peptides, aptamers, or small molecules such as vitamins or hormones. Most research studies in this field have been devoted to targeting cancer. Moreover, the nanostructures can be designed with an additional level of targeting by being designed to be stimulus-responsive or "smart" by a judicious choice of materials to be incorporated into the hybrid nanostructures. This stimulus could be an acidic pH, raised temperature, enzyme, ultrasound, redox potential, an externally applied magnetic field, or laser irradiation. In this case, the smart capability can increase the accumulation at the tumor site or the on-demand drug release, while the ligand ensures selective binding to the tumor cells. The present review highlights some interesting studies classified according to the nanostructure material. These materials include natural substances (polysaccharides), multi-walled carbon nanotubes (and halloysite nanotubes), metal-organic frameworks and covalent-organic frameworks, metal nanoparticles (gold and silver), and polymeric micelles.

An Injectable In Situ Depot-Forming Lipidic Lyotropic Liquid Crystal System for Localized Intratumoral Drug Delivery

To address the need for localized chemotherapy against unresectable solid tumors, an injectable in situ depot-forming lipidic lyotropic liquid crystal system (L3CS) is explored that can provide spatiotemporal control over drug delivery. Although liquid crystals have been studied extensively before but their application as an injectable intratumoral depot system for locoregional chemotherapy has not been explored yet. The developed L3CS in the present study is a low-viscosity injectable fluid having a lamellar phase, which transforms into a hexagonal mesophase depot system on subcutaneous or intratumoral injection. The transformed depot system can be preprogrammed to provide tailored drug release intratumorally, over a period of one week to one month. To establish the efficacy of the developed L3CS, doxorubicin is used as a model drug. The drug release mechanism is studied in detail both in vitro and in vivo, and the efficacy of the developed system is investigated in the murine 4T1 tumor model. The direct intratumoral injection of the L3CS provided localized delivery of doxorubicin inside the tumor and restricted its access within the tumor only for a sustained period of time. This led to an over 10-fold reduction in tumor burden, reduced cardiotoxicity, and a significant increase in the median survival rate, compared to the control group. The developed L3CS thus provides an efficient strategy for localized chemotherapy against unresectable solid tumors with a great degree of spatial and temporal control over drug delivery.

Local Destruction of Tumors for Systemic Immunoresponse: Engineering Antigen-Capturing Nanoparticles as Stimulus-Responsive Immunoadjuvants

Immunotherapy has established a new paradigm for cancer treatment and made many breakthroughs in clinical practice. However, the rarity of immune response suggests that additional intervention is necessary. In recent years, it has been reported that local tumor destruction (LTD) can cause cancer cell death and induce an immunologic response. Thus, the combination of immunotherapy and LTD methods will be a promising approach to improve immune efficiency for cancer treatment. Herein, a nanobiotechnology platform to achieve high-precision LTD for systemic cancer immunotherapy has been successfully constructed. Possessing radio-sensitizing and photothermal properties, the engineered immunoadjuvant-loaded nanoplatform, which could precisely induce radiotherapy (RT)/photothermal therapy (PTT) to eliminate local tumor and meanwhile lead to the release of tumor-derived protein antigens (TDPAs), has been facilely fabricated by commercialized SPG membrane emulsification technology. Further on, the TDPAs could be captured and form personal nanovaccines in situ to serve as both reservoirs of antigen and carriers of immunoadjuvant, which can effectively improve the immune response. The investigations suggest that the combination of RT/PTT and improved immunotherapy using adjuvant-encapsulated antigen-capturing nanoparticles holds tremendous promise in cancer treatments.

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.

Magnetic Self-Healing Hydrogel from Difunctional Polymers Prepared via the Kabachnik-Fields Reaction

The development of high quality magnetic self-healing hydrogels containing well-dispersed magnetic nanoparticle has been a challenging procedure due to unavailable methods of facilely introducing groups that can efficiently stabilize these magnetic nanoparticles in the self-healing hydrogels. In this research, a polymer containing both phenylboronic acid (PBA) and phosphonic acid (PA) groups has been developed by the Kabachnik-Fields (KF) reaction. This polymer well disperses iron oxide nanoparticles (IONPs) through the strong interactions between the PA groups and the surface of the IONPs; thus, this polymer effectively mixed IONPs and poly(vinyl alcohol) (PVA) to form a hydrogel containing well-dispersed IONPs. The resulting hydrogel is self-healing, owing to the dynamic borate ester linkages. Moreover, the presence of the IONPs endowed the hydrogel with magnetic properties, also making it heat-responsive in an alternating magnetic field and expanding its application as a contrast agent for magnetic resonance imaging. The magnetic self-healing hydrogel showed excellent biosafety properties in animal experiments, suggesting its potential as an injectable implant material for biological and medical applications. This research exploits a biocompatible magnetic self-healing hydrogel with well-dispersed IONPs, demonstrating the value of the KF reaction in the development of functional polymers and smart materials, which might prompt a broad study of multicomponent reactions in interdisciplinary fields.

Drug Delivery Based on Stimuli-Responsive Injectable Hydrogels for Breast Cancer Therapy: A Review

Breast cancer is the most common and biggest health threat for women. There is an urgent need to develop novel breast cancer therapies to overcome the shortcomings of conventional surgery and chemotherapy, which include poor drug efficiency, damage to normal tissues, and increased side effects. Drug delivery systems based on injectable hydrogels have recently gained remarkable attention, as they offer encouraging solutions for localized, targeted, and controlled drug release to the tumor site. Such systems have great potential for improving drug efficiency and reducing the side effects caused by long-term exposure to chemotherapy. The present review aims to provide a critical analysis of the latest developments in the application of drug delivery systems using stimuli-responsive injectable hydrogels for breast cancer treatment. The focus is on discussing how such hydrogel systems enhance treatment efficacy and incorporate multiple breast cancer therapies into one system, in response to multiple stimuli, including temperature, pH, photo-, magnetic field, and glutathione. The present work also features a brief outline of the recent progress in the use of tough hydrogels. As the breast undergoes significant physical stress and movement during sporting and daily activities, it is important for drug delivery hydrogels to have sufficient mechanical toughness to maintain structural integrity for a desired period of time.

Molecular interaction mechanisms of glycol chitosan self-healing hydrogel as a drug delivery system for gemcitabine and doxorubicin

Glycol chitosan is a derivative of chitosan that has attracted attention in recent years due to its biocompatibility and biodegradability. Due to its unique biological characteristics, it has been widely used in hydrogels and biomaterials. In this study, we explored the loading efficiency of a self-healing hydrogel (GC-DP) comprising glycol chitosan (GC) and telechelic difunctional poly(ethylene glycol) (DF-PEG) for delivering the anticancer drugs gemcitabine and doxorubicin through full atomistic simulations. We also constructed full atomistic models of the two drug delivery systems at three drug concentrations of 10%, 40%, and 80% to understand how the drug concentration affects the loading efficiency and molecular structure of the GC-DP hydrogels. Through the analysis of the results, we show that the GC-DP hydrogel exhibits excellent loading efficiency for both gemcitabine and doxorubicin at all drug concentrations (10%, 40% and 80%). Our results reveal that the main mechanism of interaction between the GC-DP hydrogels and gemcitabine is van der Waals adsorption and that the dominant interactions between the GC-DP hydrogel and doxorubicin are hydrogen bonds for the D10 model and van der Waals adsorption for the D40 and D80 models. Our results provide molecular insights into how drug molecules are carried by hydrogel materials and indicate that the GC-DP hydrogel is a promising candidate for carrying both gemcitabine and doxorubicin, and thus serving as a novel drug carrier for cancer treatment.