Thermo/pH dual-responsive micelles based on the host-guest interaction between benzimidazole-terminated graft copolymer and β-cyclodextrin-functionalized star block copolymer for smart drug delivery

Recent trends on polycaprolactone as sustainable polymer-based drug delivery system in the treatment of cancer: Biomedical applications and nanomedicine

The unique properties-such as biocompatibility, biodegradability, bio-absorbability, low cost, easy fabrication, and high versatility-have made polycaprolactone (PCL) the center of attraction for researchers. The derived introduction in this manuscript gives a pretty detailed overview of PCL, so you can first brush up on it. Discussion on the various PCL-based derivatives involves, but is not limited to, poly(ε-caprolactone-co-lactide) (PCL-co-LA), PCL-g-PEG, PCL-g-PMMA, PCL-g-chitosan, PCL-b-PEO, and PCL-g-PU specific properties and their probable applications in biomedicine. This paper has considered examining the differences in the diverse disease subtypes and the therapeutic value of using PCL. Advanced strategies for PCL in delivery systems are also considered. In addition, this review discusses recently patented products to provide a snapshot of recent updates in this field. Furthermore, the text probes into recent advances in PCL-based DDS, for example, nanoparticles, liposomes, hydrogels, and microparticles, while giving special attention to comparing the esters in the delivery of bioactive compounds such as anticancer drugs. Finally, we review future perspectives on using PCL in biomedical applications and the hurdles of PCL-based drug delivery, including fine-tuning mechanical strength/degradation rate, biocompatibility, and long-term effects in living systems.

β-Cyclodextrin-optimized supramolecular nanovesicles enhance the droplet/foliage interface interactions and inhibition of succinate dehydrogenase (SDH) for efficient treatment of fungal diseases

BACKGROUND

Plant fungal diseases present a major challenge to global agricultural production. Despite extensive efforts to develop fungicides, particularly succinate dehydrogenase inhibitors (SDHIs), their effectiveness is often limited by poor retention of fungicide droplets on hydrophobic leaves. The off-target losses and unintended release cause fungal resistance and severe environmental pollution.

RESULTS

To update the structure of existing SDHIs and synchronously realize the efficient utilization, we have employed a sophisticated supramolecular strategy to optimize a structurally novel SDH inhibitor (AoH25), creating an innovative supramolecular SDH fungicide (AoH25@β-CD), driven by the host-guest recognition principle between AoH25 and β-cyclodextrin (β-CD). Intriguingly, AoH25@β-CD self-assembles into biocompatible supramolecular nanovesicles, which reinforce the droplet/foliage (liquid-solid) interface interaction and the effective wetting and retention on leaf surfaces, setting the foundation for enhancing fungicide utilization. Mechanistic studies revealed that AoH25@β-CD exhibited significantly higher inhibition of SDH (IC50 = 1.56 µM) compared to fluopyram (IC50 = 244.41 µM) and AoH25 alone (IC50 = 2.29 µM). Additionally, AoH25@β-CD increased the permeability of cell membranes in Botryosphaeria dothidea, facilitating better penetration of active ingredients into pathogenic cells. Further experimental outcomes confirmed that AoH25@β-CD was 88.5% effective against kiwifruit soft rot at a low-dose of 100 µg mL-1, outperforming commercial fungicides such as fluopyram (52.4%) and azoxystrobin (65.4%). Moreover, AoH25@β-CD showed broad-spectrum bioactivity against oilseed rape sclerotinia, achieving an efficacy of 87.2%, outstripping those of fluopyram (48.7%) and azoxystrobin (76.7%).

CONCLUSION

This innovative approach addresses key challenges related to fungicide deposition and resistance, improving the bioavailability of agricultural chemicals. The findings highlight AoH25@β-CD as a novel supramolecular SDH inhibitor, demonstrating its potential as an efficient and sustainable solution for plant disease management.

The Many Faces of Cyclodextrins within Self-Assembling Polymer Nanovehicles: From Inclusion Complexes to Valuable Structural and Functional Elements

Most chemotherapeutic agents are poorly soluble in water, have low selectivity, and cannot reach the tumor in the desired therapeutic concentration. On the other hand, sensitive hydrophilic therapeutics like nucleic acids and proteins suffer from poor bioavailability and cell internalization. To solve this problem, new types of controlled release systems based on nano-sized self-assemblies of cyclodextrins able to control the speed, timing, and location of therapeutic release are being developed. Cyclodextrins are macrocyclic oligosaccharides characterized by a high synthetic plasticity and potential for derivatization. Introduction of new hydrophobic and/or hydrophilic domains and/or formation of nano-assemblies with therapeutic load extends the use of CDs beyond the tried-and-tested CD-drug host-guest inclusion complexes. The recent advances in nano drug delivery have indicated the benefits of the hybrid amphiphilic CD nanosystems over individual CD and polymer components. This review provides a comprehensive overview of the most recent advances in the design of CDs self-assemblies and their use for delivery of a wide range of therapeutic molecules. It aims to offer a valuable insight into the many roles of CDs within this class of drug nanocarriers as well as current challenges and future perspectives.

Intertumoral and intratumoral barriers as approaches for drug delivery and theranostics to solid tumors using stimuli-responsive materials

The solid tumors provide a series of biological barriers in cellular microenvironment for designing drug delivery methods based on advanced stimuli-responsive materials. These intertumoral and intratumoral barriers consist of perforated endotheliums, tumor cell crowding, vascularity, lymphatic drainage blocking effect, extracellular matrix (ECM) proteins, hypoxia, and acidosis. Triggering opportunities have been drawn for solid tumor therapies based on single and dual stimuli-responsive drug delivery systems (DDSs) that not only improved drug targeting in deeper sites of the tumor microenvironments, but also facilitated the antitumor drug release efficiency. Single and dual stimuli-responsive materials which are known for their lowest side effects can be categorized in 17 main groups which involve to internal and external stimuli anticancer drug carriers in proportion to microenvironments of targeted solid tumors. Development of such drug carriers can circumvent barriers in clinical trial studies based on their superior capabilities in penetrating into more inaccessible sites of the tumor tissues. In recent designs, key characteristics of these DDSs such as fast response to intracellular and extracellular factors, effective cytotoxicity with minimum side effect, efficient permeability, and rate and location of drug release have been discussed as core concerns of designing paradigms of these materials.

Colloidal and Biological Characterization of Dual Drug-Loaded Smart Micellar Systems

Smart polymeric micelles (PMs) are of great interest in drug delivery owing to their low critical micellar concentration and sizes. In the present study, two different pH-sensitive poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP-b-PEO) copolymer samples were used for the encapsulation of paclitaxel (PTX), ursolic acid (UA), and dual loading of PTX and UA. Based on the molecular features of copolymers, spherical PMs with sizes of around 35 nm and 140 nm were obtained by dialysis for P2VP55-b-PEO284 and P2VP274-b-PEO1406 samples, respectively. The micellar sizes increased after loading of both drugs. Moreover, drug encapsulation and loading efficiencies varied from 53 to 94% and from 3.2 to 18.7% as a function of the copolymer/drug ratio, molar mass of copolymer sample, and drug type. By FT-IR spectroscopy, it was possible to demonstrate the drug loading and the presence of some interactions between the polymer matrix and loaded drugs. In vitro viability was studied on 4T1 mammary carcinoma mouse cells as a function of time and concentration of drug-loaded PMs. UA-PMs and free PMs alone were not effective in inhibiting the tumor cell growth whereas a viability of 40% was determined for cells treated with both PTX- and PTX/UA-loaded PMs. A synergic effect was noticed for PTX/UA-loaded PMs.

Supramolecular Interaction Modulation in Thermosensitive Composites: Enantiomeric Recognition and Chiral Site Regeneration

Herein, a novel strategy was implemented to modulate the supramolecular interaction between enantiomers and chiral recognition sites (CRSs), effectively resolving the issue of CRS saturation. Randomly methylated-β-cyclodextrin (Rm-β-CD) was used as the CRS (host molecule), and polymerized ionic liquids [poly([vbim]TFSI)] were used as the supramolecular modulator (guest molecule), which self-assembled to generate thermosensitive supramolecular host/guest complexes. The enantiomeric binding capacity and enantioselectivity of chiral separation systems centered on supramolecular host-guest complexes are characterized by a high degree of temperature dependence. Poly([vbim]TFSI) bonded to Rm-β-CD at temperatures between 17 °C ± 3 and 50 °C ± 3 °C, and the binding free energy difference (|ΔΔG|) between the (S)- and (R)-enantiomer was 0.55. Conversely, poly([vbim]TFSI detached from Rm-β-CD at temperatures >50 °C ± 3 °C or <17 °C ± 3 °C, and |ΔΔG| between (S)- and (R)-enantiomer was 0.03. The |ΔΔG| value of the (R)-enantiomer can reach 0.86 in two temperature intervals. Therefore, the binding of poly([vbim]TFSI) to Rm-β-CD afforded the favorable separation of four racemic sample mixtures: mandelic acid (e.e.% = 61.3%), ibuprofen (e.e.% = 21.6%), warfarin (e.e.% = 14.9%), and naproxen (e.e% = 18.2%). The detachment of poly([vbim]TFSI) from Rm-β-CD released the enantiomer bound to CRSs. The decomplexation of mandelic acid reached 75.1%.

A Supramolecular Assembly of EGCG for Long-Term Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a type-I hypersensitivity disease mediated by immunoglobulin E (IgE). Although antihistamines, glucocorticoids, leukotriene receptor antagonists, and other drugs are widely used to treat AR, the various adverse side effects of long-term use of these drugs should not be ignored. Therefore, more effective and safe natural alternative strategies are urgently needed. To this end, this study designed a nanosupramolecular delivery system composed of β-cyclodextrin supramolecular polymer (PCD), thiolated chitosan (TCS), and natural polyphenol epigallocatechin gallate (EGCG) for intranasal topical continuous treatment of AR. The TCS/PCD@EGCG nanocarriers exhibited an excellent performance in terms of retention and permeability in the nasal mucosa and released the vast majority of EGCG responsively in the nasal microenvironment, thus resulting in the significantly high antibacterial and antioxidant capacities. According to the in vitro model, compared with free EGCG, TCS/PCD@EGCG inhibited mast cell activity and abnormal histamine secretion in a more long-term and sustained manner. According to the in vivo model, whether in the presence of continuous or intermittent administration, TCS/PCD@EGCG substantially inhibited the secretion of allergenic factors and inflammatory factors, mitigated the pathological changes of nasal mucosa, alleviated the symptoms of rhinitis in mice, and produced a satisfactory therapeutic effect on AR. In particular, the therapeutic effect of TCS/PCD@EGCG systems were even superior to that of budesonide during intermittent treatment. Therefore, the TCS/PCD@EGCG nanocarrier is a potential long-lasting antiallergic medicine for the treatment of AR.

Folate receptor-mediated delivery system based on chitosan coated polymeric nanoparticles for combination therapy of breast cancer

Combination therapy using two or more drugs with different mechanisms of action is an effective strategy for treating cancer. This is because of the synergistic effect of complementary drugs that enhances their effectiveness. However, this approach has some limitations, such as non-specific distribution of the drugs in the tumor and the occurrence of dose-dependent toxicity to healthy tissues. To overcome these issues, we have developed a folate receptor-mediated co-delivery system that improves the access of chemotherapy drugs to the tumor site. We prepared a nanoplatform by encapsulating paclitaxel (PTX) and curcumin (CUR) in poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone) (PCL-PEG-PCL) co-polymer using a double emulsion method and coating nanoparticles with pH-responsive chitosan-folic acid (CS-FA) conjugate. The nanocarrier's physicochemical properties were studied, confirming successful preparation with appropriate size and morphology. PTX and CUR could be released synchronously in a controlled and acid-facilitated manner. The dual drug-loaded nanocarrier exhibited excellent anti-tumor efficiency in MDA-MB-231 cells in vitro. The active targeting effect of FA concluded from the high inhibitory effect of dual drug-loaded nanocarrier on MDA-MB-231 cells, which have overexpressed folate receptors on their surface, compared to Human umbilical vein endothelial cells (HUVEC). Overall, the nanoengineered folate receptor-mediated co-delivery system provides great potential for safe and effective cancer therapy.

Tailored Drug Delivery Platforms: Stimulus-Responsive Core-Shell Structured Nanocarriers

Core-shell structured nanocarriers have come into the scientific spotlight in recent years due to their intriguing properties and wide applications in materials chemistry, biology, and biomedicine. Tailored core-shell structures to achieve desired performance have emerged as a research frontier in the development of smart drug delivery system. However, systematic reviews on the design and loading/release mechanisms of stimulus-responsive core-shell structured nanocarriers are uncommon. This review starts with the categories of core-shell structured nanocarriers with different means of drug payload, and then highlights the controlled release mechanism realized through stimulus-response processes triggered under different environments. Finally, some multifaceted perspectives on the design of core-shell structured materials as drug carriers are addressed. This work aims to provide new enlightenments and prospects in the drug delivery field for further developing advanced and smart nanocarriers.

Construction of intelligent drug delivery system based on polysaccharide-derived polymer micelles: A review

Micelles are nanostructures developed via the spontaneous assembly of amphiphilic polymers in aqueous systems, which possess the advantages of high drug stability or active-ingredient solubilization, targeted transport, controlled release, high bioactivity, and stability. Polysaccharides have excellent water solubility, biocompatibility, and degradability, and can be modified to achieve a hydrophobic core to encapsulate hydrophobic drugs, improve drug biocompatibility, and achieve regulated delivery of the loaded drug. Micelles drug delivery systems based on polysaccharides and their derivatives show great potential in the biomedical field. This review discusses the principles of self-assembly of amphiphilic polymers and the formation of micelles; the preparation of amphiphilic polysaccharides is described in detail, and an overview of common polysaccharides and their modifications is provided. We focus on the review of strategies for encapsulating drugs in polysaccharide-derived polymer micelles (PDPMs) and building intelligent drug delivery systems. This review provides new research directions that will help promote future research and development of PDPMs in the field of drug carriers.

Intelligent Systems based on Cyclodextrins for the Treatment of Breast Cancer

The incidence of breast cancer has been increasing over the last four decades, although the mortality rate has decreased. Endocrine therapy and chemotherapy are the most used options for cancer treatment but several obstacles are still attributed to these therapies. Smart materials, such as nanocarriers for targeting, delivery and release of active ingredients, sensitive to intrinsic-stimuli (pH-responsive, redox-responsive, enzyme- responsive, and thermo-responsive) and extrinsic-stimuli (ultrasound-responsive, magnetic-responsive, light-responsive) have been studied as a novel strategy in breast cancer therapy. Cyclodextrins (CDs) are used in the design of these stimuli-responsive drug carrier and delivery systems, either through inclusion complexes with hydrophobic molecules or covalent bonds with large structures to generate new materials. The present work aims to gather and integrate recent data from in vitro and in vivo preclinical studies of CD-based stimuli- responsive systems to contribute to the research in treating breast cancer. All drug carriers showed high in vitro release rates in the presence of a stimulus. The stimuli-responsive nanoplatforms presented biocompatibility and satisfactory results of IC50, inhibition of cell viability and antitumor activity against several breast cancer cell lines. Additionally, these systems led to a significant reduction in drug dosages, which encouraged possible clinical studies for better alternatives to traditional antitumor therapies.

Multi-stimuli-responsive Hydrogels for Therapeutic Systems: An Overview on Emerging Materials, Devices, and Drugs

The rising interest in hydrogels nowadays is due to their usefulness in physiological conditions as multi-stimuli-responsive hydrogels. To reply to the prearranged stimuli, including chemical triggers, light, magnetic field, electric field, ionic strength, temperature, pH, and glucose levels, dual/multi-stimuli-sensitive gels/hydrogels display controllable variations in mechanical characteristics and swelling. Recent attention has focused on injectable hydrogel-based drug delivery systems (DDS) because of its promise to offer regulated, controlled, and targeted medication release to the tumor site. These technologies have great potential to improve treatment outcomes and lessen side effects from prolonged chemotherapy exposure.

Supramolecular host-guest nanosystems for overcoming cancer drug resistance

Cancer drug resistance has become one of the main challenges for the failure of chemotherapy, greatly limiting the selection and use of anticancer drugs and dashing the hopes of cancer patients. The emergence of supramolecular host-guest nanosystems has brought the field of supramolecular chemistry into the nanoworld, providing a potential solution to this challenge. Compared with conventional chemotherapeutic platforms, supramolecular host-guest nanosystems can reverse cancer drug resistance by increasing drug uptake, reducing drug efflux, activating drugs, and inhibiting DNA repair. Herein, we summarize the research progress of supramolecular host-guest nanosystems for overcoming cancer drug resistance and discuss the future research direction in this field. It is hoped that this review will provide more positive references for overcoming cancer drug resistance and promoting the development of supramolecular host-guest nanosystems.

Spectroscopic Insights of an Emissive Complex between 4'-N,N-Diethylaminoflavonol in Octa-Acid Deep-Cavity Cavitand and Rhodamine 6G

Excited-state chemistry relies on the communication between molecules, making it a crucial aspect of the field. One important question that arises is whether intermolecular communication and its rate can be modified when a molecule is confined. To explore the interaction in such systems, we investigated the ground and excited states of 4'-N,N-diethylaminoflavonol (DEA3HF) in an octa acid-based (OA) confined medium and in ethanolic solution, both in the presence of Rhodamine 6G (R6G). Despite the observed spectral overlap between the flavonol emission and the R6G absorption, as well as the fluorescence quenching of the flavonol in the presence of R6G, the almost constant fluorescence lifetime at different amounts of R6G discards the presence of FRET in the studied systems. Steady-state and time-resolved fluorescence indicate the formation of an emissive complex between the proton transfer dye encapsulated within water-soluble supramolecular host octa acid (DEA3HF@(OA)₂) and R6G. A similar result was observed between DEA3HF:R6G in ethanolic solution. The respective Stern-Volmer plots corroborate with these observations, suggesting a static quenching mechanism for both systems.

The Role of Cyclodextrin in the Construction of Nanoplatforms: From Structure, Function and Application Perspectives

Cyclodextrins (CyDs) in nano drug delivery systems have received much attention in pursuit of good compatibility, negligible toxicity, and improved pharmacokinetics of drugs. Their unique internal cavity has widened the application of CyDs in drug delivery based on its advantages. Besides this, the polyhydroxy structure has further extended the functions of CyDs by inter- and intramolecular interactions and chemical modification. Furthermore, the versatile functions of the complex contribute to alteration of the physicochemical characteristics of the drugs, significant therapeutic promise, a stimulus-responsive switch, a self-assembly capability, and fiber formation. This review attempts to list recent interesting strategies regarding CyDs and discusses their roles in nanoplatforms, and may act as a guideline for developing novel nanoplatforms. Future perspectives on the construction of CyD-based nanoplatforms are also discussed at the end of this review, which may provide possible direction for the construction of more rational and cost-effective delivery vehicles.

Effect of temperature on the structure and drug-release behaviour of inclusion complex of β-cyclodextrin with cyclophosphamide: a molecular dynamics study

Cyclodextrins (CDs) are suitable drug carriers because of their doughnut-shaped cavities with hydrophilic outer and hydrophobic inner surfaces. Temperature-responsive CD-based drug carriers are expected to be one of the most promising candidates for drug delivery systems. In this study, we performed molecular dynamics simulations of the inclusion complex of β-CD with cyclophosphamide (CP) at temperatures from 300 K to 400 K to investigate the temperature dependency of the release behaviour of CP and structural changes of β-CD in an aqueous solution. We analysed the distance between the centres of mass of β-CD and CP and the radius of gyration of β-CD. The CP molecule was released from the β-CD cavity at 400 K, whereas two different inclusion complexes, partially and completely, were observed at T < 400 K. β-CD encapsulating a CP molecule had a more spherical shape and rigidity than β-CD without a CP, and the rigidity of their inclusion complex decreased with increasing temperature. Our findings provide fundamental insights into the behaviours of the β-CD/CP complex and drug release at the molecular level and can facilitate the development of new temperature-responsive drug delivery systems with CD nanocarriers triggered by localised temperature increases using focused ultrasound.

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Self-Assembled Redox-Sensitive Polymeric Nanostructures Facilitate the Intracellular Delivery of Paclitaxel for Improved Breast Cancer Therapy

A two-tier approach has been proposed for targeted and synergistic combination therapy against metastatic breast cancer. First, it comprises the development of a paclitaxel (PX)-loaded redox-sensitive self-assembled micellar system using betulinic acid-disulfide-d-α-tocopheryl poly(ethylene glycol) succinate (BA-Cys-T) through carbonyl diimidazole (CDI) coupling chemistry. Second, hyaluronic acid is anchored to TPGS (HA-Cys-T) chemically through a cystamine spacer to achieve CD44 receptor-mediated targeting. We have established that there is significant synergy between PX and BA with a combination index of 0.27 at a molar ratio of 1:5. An integrated system comprising both BA-Cys-T and HA-Cys-T (PX/BA-Cys-T-HA) exhibited significantly higher uptake than PX/BA-Cys-T, indicating preferential CD44-mediated uptake along with the rapid release of drugs in response to higher glutathione concentrations. Significantly higher apoptosis (42.89%) was observed with PX/BA-Cys-T-HA than those with BA-Cys-T (12.78%) and PX/BA-Cys-T (33.38%). In addition, PX/BA-Cys-T-HA showed remarkable enhancement in the cell cycle arrest, improved depolarization of the mitochondrial membrane potential, and induced excessive generation of ROS when tested in the MDA-MB-231 cell line. An in vivo administration of targeted micelles showed improved pharmacokinetic parameters and significant tumor growth inhibition in 4T1-induced tumor-bearing BALB/c mice. Overall, the study indicates a potential role of PX/BA-Cys-T-HA in achieving both temporal and spatial targeting against metastatic breast cancer.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Polymeric Membranes for Biomedical Applications

Polymeric membranes are selective materials used in a wide range of applications that require separation processes, from water filtration and purification to industrial separations. Because of these materials' remarkable properties, namely, selectivity, membranes are also used in a wide range of biomedical applications that require separations. Considering the fact that most organs (apart from the heart and brain) have separation processes associated with the physiological function (kidneys, lungs, intestines, stomach, etc.), technological solutions have been developed to replace the function of these organs with the help of polymer membranes. This review presents the main biomedical applications of polymer membranes, such as hemodialysis (for chronic kidney disease), membrane-based artificial oxygenators (for artificial lung), artificial liver, artificial pancreas, and membranes for osseointegration and drug delivery systems based on membranes.

Multifunctional Polymeric Micelles for Cancer Therapy

Polymeric micelles, nanosized assemblies of amphiphilic polymers with a core-shell architecture, have been used as carriers for various therapeutic compounds. They have gained attention due to specific properties such as their capacity to solubilize poorly water-soluble drugs, biocompatibility, and the ability to accumulate in tumor via enhanced permeability and retention (EPR). Moreover, additional functionality can be provided to the micelles by a further modification. For example, micelle surface modification with targeting ligands allows a specific targeting and enhanced tumor accumulation. The introduction of stimuli-sensitive groups leads to the drug's release in response to environment change. This review highlights the progress in the development of multifunctional polymeric micelles in the field of cancer therapy. This review will also cover some examples of multifunctional polymeric micelles that are applied for tumor imaging and theragnosis.

In situ Injection of pH- and Temperature-Sensitive Nanomaterials Increases Chemo-Photothermal Efficacy by Alleviating the Tumor Immunosuppressive Microenvironment

Purpose

Triple-negative breast cancer (TNBC) is challenging to treat with traditional "standard of care" therapy due to the lack of targetable biomarkers and rapid progression to distant metastasis.

Methods

We synthesized a novel combination regimen that included chemotherapy and photothermal therapy (PTT) to address this problem. Here, we tested a magnetic nanosystem (MNs-PEG/IR780-DOX micelles) loaded with the near-infrared (NIR) photothermal agent IR780 and doxorubicin (DOX) to achieve chemo-photothermal and boost antitumor immunity. Intraductal (i.duc) administration of MNs-PEG/IR780-DOX could increase the concentration of the drug in the tumor while reducing systemic side effects.

Results

We showed more uptake of MNs-PEG/IR780-DOX by 4T1-luc cells and higher penetration in the tumor. MNs-PEG/IR780-DOX exhibited excellent photothermal conversion in vivo and in vitro. The release of DOX from MNs-PEG/IR780-DOX is pH- and temperature-sensitive. Facilitated by i.duc administration, MNs-PEG/IR780-DOX displayed antitumor effects and prevented distant organs metastasis under NIR laser (L) irradiation and magnetic field (MF)while avoiding DOX-induced toxicity. More importantly, MNs-PEG/IR780-DOX alleviated tumor immunosuppressive microenvironment by increasing tumor CD8⁺ T cells infiltration and reducing the proportion of myeloid-derived suppressor cells (MDSCs) and Tregs.

Conclusion

Intraductal administration of pH- and temperature-sensitive MNs-PEG/IR780-DOX with L and MF had the potential for achieving minimally invasive, targeted, and accurate treatment of TNBC.