Bubble-generating polymersomes loaded with both indocyanine green and doxorubicin for effective chemotherapy combined with photothermal therapy

ROS-Responsive Nanoprobes for Bimodal Imaging-Guided Cancer Targeted Combinatorial Therapy

Purpose

Chemotherapy mediated by Reactive oxygen species (ROS)-responsive drug delivery systems can potentially mitigate the toxic side effects of chemotherapeutic drugs and significantly enhance their therapeutic efficacy. However, achieving precise targeted drug delivery and real-time control of ROS-responsive drug release at tumor sites remains a formidable challenge. Therefore, this study aimed to describe a ROS-responsive drug delivery system with specific tumor targeting capabilities for mitigating chemotherapy-induced toxicity while enhancing therapeutic efficacy under guidance of Fluorescence (FL) and Magnetic resonance (MR) bimodal imaging.

Methods

Indocyanine green (ICG), Doxorubicin (DOX) prodrug pB-DOX and Superparamagnetic iron oxide (SPIO, Fe3O4) were encapsulated in poly(lactic-co-glycolic acid) (PLGA) by double emulsification method to prepare ICG/ pB-DOX/ Fe3O4/ PLGA nanoparticles (IBFP NPs). The surface of IBFP NPs was functionalized with mammaglobin antibodies (mAbs) by carbodiimide method to construct the breast cancer-targeting mAbs/ IBFP NPs (MIBFP NPs). Thereafter, FL and MR bimodal imaging ability of MIBFP NPs was evaluated in vitro and in vivo. Finally, the combined photodynamic therapy (PDT) and chemotherapy efficacy evaluation based on MIBFP NPs was studied.

Results

The multifunctional MIBFP NPs exhibited significant targeting efficacy for breast cancer. FL and MR bimodal imaging clearly displayed the distribution of the targeting MIBFP NPs in vivo. Upon near-infrared laser irradiation, the MIBFP NPs loaded with ICG effectively generated ROS for PDT, enabling precise tumor ablation. Simultaneously, it triggered activation of the pB-DOX by cleaving its sensitive moiety, thereby restoring DOX activity and achieving ROS-responsive targeted chemotherapy. Furthermore, the MIBFP NPs combined PDT and chemotherapy to enhance the efficiency of tumor ablation under guidance of bimodal imaging.

Conclusion

MIBFP NPs constitute a novel dual-modality imaging-guided drug delivery system for targeted breast cancer therapy and offer precise and controlled combined treatment options.

SrTiO3 Nanotube-Based "Pneumatic Nanocannon" for On-Demand Delivery of Antibacterial and Sustained Osseointegration Enhancement

Infection and aseptic loosening caused by bacteria and poor osseointegration remain serious challenges for orthopedic implants. The advanced surface modification of implants is an effective strategy for addressing these challenges. This study presents a "pneumatic nanocannon" coating for titanium orthopedic implants to achieve on-demand release of antibacterial and sustained release of osteogenic agents. SrTiO3 nanotubes (SrNT) were constructed on the surface of Ti implants as "cannon barrel," the "cannonball" (antibiotic) and "propellant" (NH4HCO3) were codeposited into SrNT with assistance of mussel-inspired copolymerization of dopamine and subsequently sealed by a layer of polydopamine. The encapsulated NH4HCO3 within the nanotubes could be thermally decomposed into gases under near-infrared irradiation, propelling the on-demand delivery of antibiotics. This coating demonstrated significant efficacy in eliminating typical pathogenic bacteria both in planktonic and biofilm forms. Additionally, this coating exhibited a continuous release of strontium ions, which significantly enhanced the osteogenic differentiation of preosteoblasts. In an implant-associated infection rat model, this coating demonstrated substantial antibacterial efficiency (>99%) and significant promotion of osseointegration, along with alleviated postoperative inflammation. This pneumatic nanocannon coating presents a promising approach to achieving on-demand infection inhibition and sustained osseointegration enhancement for titanium orthopedic implants.

Real time monitoring peripheral nerve function with ICG and BDA-ICG by NIR-II fluorescence imaging

Neuroanatomical tract tracers are important for studying axoplasmic transport and the complex interconnections of the nervous system. Though traditional fluorescent tracers are widely used, they have several prominent drawbacks when imaging, including low resolutions and low tissue penetrations and inability to be supervised dynamically within a long peripheral nerve during the long term. Here, we explored the potential of ICG as a neural tracer for axoplasmic transport and for the first time demonstrated that ICG could be used to detect transport function within peripheral nerve by near-infrared region II (NIR-II) imaging. On basis of this finding, a novel bi-directional neural tracer biotinylated dextran amine-indocyanine green (BDA-ICG) was prepared and characterized with better long-term stability and higher nerve-to-background ratio than ICG in vivo, and successfully imaged the injured peripheral nerve from the healthy one within 24 h. Our results show that BDA-ICG are promising neural tracers and clinically available dyes with NIR-II emission tail characteristics as ICG.

Polymersomes as Innovative, Stimuli-Responsive Platforms for Cancer Therapy

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

Antibody-Conjugated Polymersomes with Encapsulated Indocyanine Green J-Aggregates and High Near-Infrared Absorption for Molecular Photoacoustic Cancer Imaging

Imaging plays a critical role in all stages of cancer care from early detection to diagnosis, prognosis, and therapy monitoring. Recently, photoacoustic imaging (PAI) has started to emerge into the clinical realm due to its high sensitivity and ability to penetrate tissues up to several centimeters deep. Herein, we encapsulated indocyanine green J (ICGJ) aggregate, one of the only FDA-approved organic exogenous contrast agents that absorbs in the near-infrared range, at high loadings up to ∼40% w/w within biodegradable polymersomes (ICGJ-Ps) composed of poly(lactide-co-glycolide-b-polyethylene glycol) (PLGA-b-PEG). The small Ps hydrodynamic diameter of 80 nm is advantageous for in vivo applications, while directional conjugation with epidermal growth factor receptor (EGFR) targeting cetuximab antibodies renders molecular specificity. Even when exposed to serum, the ∼11 nm-thick membrane of the Ps prevents dissociation of the encapsulated ICGJ for at least 48 h with a high ratio of ICGJ to monomeric ICG absorbances (i.e., I895/I780 ratio) of approximately 5.0 that enables generation of a strong NIR photoacoustic (PA) signal. The PA signal of polymersome-labeled breast cancer cells is proportional to the level of cellular EGFR expression, indicating the feasibility of molecular PAI with antibody-conjugated ICGJ-Ps. Furthermore, the labeled cells were successfully detected with PAI in highly turbid tissue-mimicking phantoms up to a depth of 5 mm with the PA signal proportional to the amount of cells. These data show the potential of molecular PAI with ICGJ-Ps for clinical applications such as tumor margin detection, evaluation of lymph nodes for the presence of micrometastasis, and laparoscopic imaging procedures.

Polymersome Membrane Engineering with Active Targeting or Controlled Permeability for Responsive Drug Delivery

Polymersomes have been extensively investigated for drug delivery as nanocarriers for two decades due to a series of advantages including high stability under physiological conditions, simultaneous encapsulation of hydrophilic and hydrophobic drugs inside inner cavities and membranes, respectively, and facile adjustment of membrane and surface properties, as well as controlled drug release through incorporation of stimuli-responsive components. Despite these features, polymersome nanocarriers frequently suffer from nontargeting delivery and poor membrane permeability. In recent years, polymersomes have been functionalized for more efficient drug delivery. The surface shells were explored to be modified with diverse active targeting groups to improve disease-targeting delivery. The membrane permeability of the polymersomes was adjusted by incorporation of the stimuli-responsive components for smart controlled transportation of the encapsulated drugs. Therefore, being the polymersome-biointerface, tailorable properties can be introduced by its carefully modulated engineering. This review elaborates on the role of polymersome membranes as a platform to incorporate versatile features. First, we discuss how surface functionalization facilitates the directional journey to the targeting sites toward specific diseases, cells, or intracellular organelles via active targeting. Moreover, recent advances in the past decade related to membrane permeability to control drug release are also summarized. We finally discuss future development to promote polymersomes as in vivo drug delivery nanocarriers.

Polymer Vesicles with Integrated Photothermal Responsiveness

Functionalized polymer vesicles have been proven to be highly promising in biomedical applications due to their good biocompatibility, easy processability, and multifunctional responsive capacities. However, photothermal-responsive polymer vesicles triggered by near-infrared (NIR) light have not been widely reported until now. Herein, we propose a new strategy for designing NIR light-mediated photothermal polymer vesicles. A small molecule (PTA) with NIR-triggered photothermal features was synthesized by combining a D-D'-A-D'-D configuration framework with a molecular rotor function (TPE). The feasibility of the design strategy was demonstrated through density functional theory calculations. PTA moieties were introduced in the hydrophobic segment of a poly(ethylene glycol)-poly(trimethylene carbonate) block copolymer, of which the carbonate monomers were modified in the side chain with an active ester group. The amphiphilic block copolymers (PEG44-PTA2) were then used as building blocks for the self-assembly of photothermal-responsive polymer vesicles. The new class of functionalized polymer vesicles inherited the NIR-mediated high photothermal performance of the photothermal agent (PTA). After NIR laser irradiation for 10 min, the temperature of the PTA-Ps aqueous solution was raised to 56 °C. The photothermal properties and bilayer structure of PTA-Ps after laser irradiation were still intact, which demonstrated that they could be applied as a robust platform in photothermal therapy. Besides their photothermal performance, the loading capacity of PTA-Ps was investigated as well. Hydrophobic cargo (Cy7) and hydrophilic cargo (Sulfo-Cy5) were successfully encapsulated in the PTA-Ps. These properties make this new class of functionalized polymer vesicles an interesting platform for synergistic therapy in anticancer treatment.

Acidity/carbon dioxide-sensitive triblock polymer-grafted photoactivated vesicles for programmed release of chemotherapeutic drugs against glioblastoma

Controllable release of chemotherapeutic drugs in tumor sites remains a big challenge for precision therapy. Herein, we developed acidity/carbon dioxide (H⁺/CO₂)-sensitive poly (ethylene glycol)-b-poly (2-(diisopropylamino) ethyl methacrylate)-b-polystyrene triblock polymer (PEG-b-PDPA-b-PS) grafted photoactivated vesicles for programmed release of chemotherapeutic drugs against glioblastoma. In brief, gold nanoparticles (GNPs) were firstly tethered with the H⁺/CO₂-sensitive PEG-b-PDPA-b-PS polymer. Next, the CO₂ precursor (ammonium bicarbonate, NH₄HCO₃) and doxorubicin (DOX) were loaded during self-assembly process of PEG-b-PDPA-b-PS-tethered GNPs, thus obtaining the multifunctional gold vesicles (denoted as GVND). The programmed multi-stimuli responsive drug release by GVND was undergone in multiple steps as follows: 1) the vesicular architecture of GVND was first swelled in tumor acidic microenvironment, 2) the GVND were partially broken under near-infrared (NIR) laser irradiation, 3) the mild hyperthermia generated by GV triggered the thermal decomposition of encapsulated NH₄HCO₃, leading to the in situ generation of CO₂, 4) the generated CO₂ reacted with PDPA of PEG-b-PDPA-b-PS, changing the hydrophilicity and hydrophobicity of GVND, thus vastly breaking its vesicular architecture, finally resulting in a "bomb-like" release of DOX in tumor tissues. Such a multi-stimuli responsive programmed drug delivery and mild hyperthermia under NIR laser activation displayed strong antitumor efficacy and completely eradicated U87MG glioblastoma tumor. This work presented a promising strategy to realize precision drug delivery for chemotherapy against glioblastoma. STATEMENT OF SIGNIFICANCE.

Cyclic RGD functionalized PLGA nanoparticles loaded with noncovalent complex of indocyanine green with urokinase for synergistic thrombolysis

Thrombotic diseases have the characteristics of long latency period, rapid onset, and high mortality rate, which seriously threaten people's life and health. The aim of this research is to fabricate a novel indocyanine green complex of urokinase (ICG@uPA) and employ the amphiphilic PEG-PLGA polymer to deliver the complex as an enzyme-phototherapeutic synergistic thrombolysis platform. The noncovalent indocyanine green (ICG) complex of urokinase (ICG@uPA) was prepared via supramolecular self-assembly and then encapsulated into cRGD decorated polymeric nanoparticles (cRGD-ICG-uPA NPs) by double-emulsion solvent evaporation method. Then the nanoparticles (NPs) were characterized in terms of particle size, optical properties, in vitro release, etc. The targeting and thrombolytic effect of the nanoparticles were studied both in vitro and in vivo. ICG@uPA and cRGD-ICG-uPA NPs displayed significantly higher photostability and laser energy conversion efficiency than free ICG. Concomitantly, the NPs exhibited selective binding affinity to the activated platelets and specific accumulation in the mouse mesenteric vessel thrombus. Significant thrombolysis was achieved in vivo by photo-assisted synergistic therapy with reduced dose and systemic bleeding risk of uPA. Our results prove that the functional PLGA nanoparticle loaded with the ICG@uPA offers a novel option for effective and safe thrombolytic treatment.

Recent advances in mesoporous silica nanoparticle-based targeted drug-delivery systems for cancer therapy

Targeted drug-delivery systems are a growing research topic in tumor treatment. In recent years, mesoporous silica nanoparticles (MSNs) have been extensively studied and applied in noninvasive and biocompatible drug-delivery systems for tumor therapy due to their outstanding advantages, which include high surface area, large pore volume, tunable pore size, easy surface modification and stable framework. The advances in the application of MSNs for anticancer drug targeting are covered and highlighted in this review, and the challenges and prospects of MSN-based targeted drug-delivery systems are discussed. This review provides new insights for researchers interested in targeted drug-delivery systems against cancer.

Nitric oxide-containing supramolecular polypeptide nanomedicine based on [2]biphenyl-extended-pillar[6]arenes for drug resistance reversal

A kind of supramolecular polypeptide nanomedicine (BPC/DOX-ICG) was constructed with an anionic water-soluble [2]biphenyl-extended-pillar[6]arene (AWBpP6), and pyridinium-terminal- and S-nitrosothiol (SNO)-modified polypeptide (PPNC) via host-guest interactions to co-deliver doxorubicin (DOX) and indocyanine green (ICG) for drug resistance reversal. Upon near-infrared (NIR) irradiation, the NO generation could down-regulate the P-glycoprotein (P-gp) expression level to reverse multidrug resistance (MDR). Subsequently, the resulting reverse MDR could sensitize the free DOX and assist photothermal therapy (PTT) to enhance the tumoricidal potential. This supramolecular polypeptide nanomedicine provides an effective strategy for the multimodal synergistic therapies of photothermal therapy, NO generation therapy, and chemotherapy (i.e., PTT-NO-CT) to overcome MDR.

Codelivery of π-π Stacked Dual Anticancer Drugs Based on Aloe-Derived Nanovesicles for Breast Cancer Therapy

To overcome the low efficacy of conventional monotherapeutic approaches that use a single drug, functional nanocarriers loaded with an amalgamation of anticancer drugs have been promising in cancer therapy. Herein, aloe-derived nanovesicles (gADNVs) are modified with an active integrin-targeted peptide (Arg-Gly-Asp, RGD) by the postinsertion technique to deliver indocyanine green (ICG) and doxorubicin (DOX) for efficient breast cancer therapy. We presented for the first time that the π-π stacking interaction can turn the "competitive" relationship of ICG and DOX inside gADNVs into a "cooperative" relationship and enhance their loading efficiency. The dual-drug codelivery nanosystem, denoted as DIARs, was well stable and leakproof, exhibiting high tumor-targeting capability both in vitro and in vivo. Meanwhile, this nanosystem showed significant inhibition of cell growth and migration and induced cell apoptosis with the combination of phototherapy and chemotherapy. Intravenous administration of DIARs exhibited high therapeutic efficacy in a 4T1 tumor-bearing mouse model and exhibited no obvious damage to other organs. Overall, our DIAR nanosystem constitutively integrated the natural and economical gADNVs, π-π stacking interaction based on efficient drug loading, and tumor-targeted RGD modification to achieve an effective combination therapy for breast cancer.

NIR-Mediated drug release and tumor theranostics using melanin-loaded liposomes

BACKGROUND

Heat generation in a drug delivery carrier by exposure to near-infrared (NIR) light with excellent tissue transmittance is an effective strategy for drug release and tumor therapy. Because liposomes have amphiphilic properties, they are useful as drug carriers. Liposomes are also very suitable for drug delivery strategies using heat generation by NIR laser because lipid bilayers are easily broken by heat. Thermally generated bubbles from liposomes not only induce drug release, but also enable ultrasound imaging.

METHODS

Melanin, perfluorohexane (PFH), and 5-fluorouracil (5-FU)-loaded liposomes (melanin@PFH@5-FU-liposomes) that can generate heat and bubble by NIR laser irradiation were prepared by a thin film method. Conversion of light to heat and bubble generation of melanin@PFH@5-FU-liposomes were evaluated using an infrared (IR) thermal imaging camera and an ultrasound imaging system both in vitro and in vivo. To investigate tumor therapeutic effect, NIR laser of 808 nm was used to irradiate tumor site for 10 min after injecting melanin@PFH@5-FU-liposome into tail veins of CT26-bearing mice.

RESULTS

Melanin@PFH@5-FU-liposomes showed a spherical shape with a size of 209.6 ± 4.3 nm. Upon NIR laser irradiation, melanin@PFH@5-FU-liposomes exhibited effective temperature increase both in vitro and in vivo. In this regard, temperature increase caused a phase transition of PFH to induce bubble generation dramatically, resulting in effective drug release behavior and ultrasound imaging. The temperature of the tumor site was increased to 52 t and contrast was greatly enhanced during ultrasound imaging due to the generation of bubble. More importantly, tumor growth was effectively inhibited by injection of melanin@PFH@5-FU-liposomes with laser irradiation.

CONCLUSIONS

Based on intrinsic photothermal properties of melanin and phase transition properties of PFH, melanin@PFH@5-FU-liposomes exhibited effective heat and bubble generation upon NIR laser irradiation. The elevated temperature induced bubble generation, resulting in contrast enhancement of ultrasound imaging. Melanin@PFH@5-FU-liposomes under NIR laser irradiation induced the death of cancer cells, thereby effectively inhibiting tumor growth. These results suggest that melanin@PFH@5-FU-liposomes can be utilized as a promising agent for photothermal tumor therapy and ultrasound imaging.

Light-Triggered Polymersome-Based Anticancer Therapeutics Delivery

Polymersomes are biomimetic cell membrane-like model structures that are self-assembled stepwise from amphiphilic copolymers. These polymeric (nano)carriers have gained the scientific community's attention due to their biocompatibility, versatility, and higher stability than liposomes. Their tunable properties, such as composition, size, shape, and surface functional groups, extend encapsulation possibilities to either hydrophilic or hydrophobic cargoes (or both) and their site-specific delivery. Besides, polymersomes can disassemble in response to different stimuli, including light, for controlling the "on-demand" release of cargo that may also respond to light as photosensitizers and plasmonic nanostructures. Thus, polymersomes can be spatiotemporally stimulated by light of a wide wavelength range, whose exogenous response may activate light-stimulable moieties, enhance the drug efficacy, decrease side effects, and, thus, be broadly employed in photoinduced therapy. This review describes current light-responsive polymersomes evaluated for anticancer therapy. It includes light-activable moieties' features and polymersomes' composition and release behavior, focusing on recent advances and applications in cancer therapy, current trends, and photosensitive polymersomes' perspectives.

Injectable and Temperature-Sensitive Titanium Carbide-Loaded Hydrogel System for Photothermal Therapy of Breast Cancer

Recently, organic–inorganic hybrid materials have gained much attention as effective photothermal agents for cancer treatment. In this study, Pluronic F127 hydrogel-coated titanium carbide (Ti₃C₂) nanoparticles were utilized as an injectable photothermal agent. The advantages of these nanoparticles are their green synthesis and excellent photothermal efficiency. In this system, lasers were mainly used to irradiate Ti₃C₂ nanoparticles to produce a constant high temperature, which damaged cancer cells. The nanoparticles were found to be stable during storage at low temperatures for at least 2 weeks. The Ti₃C₂ nanoparticles exhibited a shuttle-shaped structure, and the hydrogels presented a loosely meshed structure. In addition, Ti₃C₂ nanoparticles did not affect the reversible temperature sensitivity of the gel, and the hydrogel did not affect the photothermal properties of Ti₃C₂ nanoparticles. The in vitro and in vivo results show that this hydrogel system can effectively inhibit tumor growth upon exposure to near-infrared irradiation with excellent biocompatibility and biosafety. The photothermal agent-embedded hydrogel is a promising photothermal therapeutic strategy for cancer treatment by enhancing the retention in vivo and elevating the local temperature in tumors.

In situ formation of a near-infrared controlled dual-antibacterial platform

An in situ formed antibacterial platform was designed for near-infrared controlled pharmacotherapy and photothermal therapy of drug-resistant bacteria.

Self-assembled tocopherol-albumin nanoparticles with full biocompatibility for chemo-photothermal therapy against breast cancer

BACKGROUND

The combination of photothermal therapy (PTT) and chemotherapy has proven to be a promising strategy for cancer treatment. Various nanomaterials have shown great potential in combination therapy, including gold, graphene oxide, iron oxide, and other nanoparticles. However, their undefinable toxicity in vivo greatly slowed down their development for clinical applications.

OBJECTIVE

The present work aimed to develop a multifunctional nanoparticle for chemo-photothermal therapy composed of acknowledged biocompatible materials.

METHODS

A novel biocompatible nanoparticle (HIT-NPs) was self-assembled through the intrinsic interaction between D-α-tocopherol Succinate (TOS), human serum albumin (HSA) and indocyanine green (ICG). Doxorubicin (DOX) was then loaded due to the ion pairing between DOX and TOS. The feasibility of combined chemo-photothermal therapy induced by DOX-loaded HIT-NPs was carefully evaluated.

RESULTS

In vitro, HIT-NPs showed no cytotoxicity on human normal liver cells (HL-7702 cells) but obvious killing effects murine breast cancer cells (4T1 cells). The combined chemo-photothermal therapeutic effect on 4T1 cells was successfully obtained. DOX-loaded HIT-NPs could effectively accumulate in 4T1 subcutaneous tumors after intravenous injection, and the tumor temperature rapidly increased under laser exposure, indicating the feasibility of PTT in vivo.

CONCLUSION

The self-assembled HIT-NPs could provide a promising platform for combined chemo-photothermal cancer therapy with full biocompatibility.

Phototherapy and multimodal imaging of cancers based on perfluorocarbon nanomaterials

Phototherapy, such as photodynamic therapy (PDT) and photothermal therapy (PTT), possesses unique characteristics of non-invasiveness and minimal side effects in cancer treatment, compared with conventional therapies. However, the ubiquitous tumor hypoxia microenvironments could severely reduce the efficacy of oxygen-consuming phototherapies. Perfluorocarbon (PFC) nanomaterials have shown great practical value in carrying and transporting oxygen, which makes them promising agents to overcome tumor hypoxia and extend reactive oxygen species (ROS) lifetime to improve the efficacy of phototherapy. In this review, we summarize the latest advances in PFC-based PDT and PTT, and combined multimodal imaging technologies in various cancer types, aiming to facilitate their application-oriented clinical translation in the future.

Hyaluronic acid-modified manganese dioxide-enveloped hollow copper sulfide nanoparticles as a multifunctional system for the co-delivery of chemotherapeutic drugs and photosensitizers for efficient synergistic antitumor treatments

This paper presents the design of a new type of intelligent and versatile all-in-one therapeutic nanoplatform for the co-delivery of chemotherapeutic drugs and photosensitizers to facilitate multimodal antitumor treatment; the system is based on hyaluronic acid (HA)-modified manganese dioxide (MnO₂)-enveloped hollow porous copper sulfide (CuS) nanoparticles (CuS@MnO₂/HA NPs). In this system, a CuS inner shell allows for the co-loading of doxorubicin (DOX) and indocyanine green (ICG) and induces photothermal effects, and a biodegradable MnO₂ external shell affords on-demand tumor microenvironment (TME)-triggered release and catalase- andFenton-like activities. Moreover, the HA modification endows the system with a CD44 receptor-mediated tumor-targeting property. The formulated DOX and ICG co-loaded CuS@MnO₂/HA (DOX/ICG-CuS@MnO₂/HA) NPs were found to exhibit excellent photothermal performance both in vitro and in vivo. In addition, DOX/ICG-CuS@MnO₂/HA NPs were found to display both TME and near-infrared (NIR)-responsive controlled release properties. The NPs also have a superior reactive oxygen species (ROS) generation capacity due to the combination of enhanced ICG-induced singlet oxygen and CuS@MnO₂-mediated hydroxyl radicals. The cellular uptake, fluorescence imaging property, cytotoxicity, and thermal imaging of these NPs were also evaluated. In tumor-bearing mice, the DOX/ICG-CuS@MnO₂/HA NPs displayeda superior antitumor efficacy (2.57-fold) as compared with free DOX. Therefore, the developed DOX/ICG-CuS@MnO₂/HA NPs have a great potential for use as an all-in-one nanotherapeutic agent for the efficient and precise induction of chemo/photothermal/photodynamic/chemodynamic therapy with superior antitumor efficacy and fewer side effects.

Oxygen- and bubble-generating polymersomes for tumor-targeted and enhanced photothermal-photodynamic combination therapy

As a common feature of the tumor microenvironment (TME), hypoxia significantly impedes the effects of photodynamic therapy. Moreover, for tumor combination therapy, smart responsive and well-designed nanocarriers are highlighted to co-deliver different therapeutics, enhance drug delivery into target sites, and realize stimuli-responsive drug release. Herein, oxygen- and bubble-generating polymersomes (FIMPs) were developed for tumor-targeted and enhanced photothermal-photodynamic combination therapy. FIMPs efficiently co-encapsulated manganese dioxide (MnO₂) and the hydrophobic photosensitizer indocyanine green (ICG) within the hydrophobic membrane as well as the bubble-generating reagent NH₄HCO₃ in the internal cavity of the vesicles, and achieved pH/temperature/reduction multiple responsiveness. The CO₂ bubbles generated from the decomposition of NH₄HCO₃via laser irradiation or acidic environment and the cleavage of the copolymer disulfide bond in the reducing TME would destroy the vesicle structure for triggering drug release. In addition, oxygen can be produced to overcome tumor hypoxia through the high reaction activity of MnO₂ with endogenous H₂O₂. In vitro studies have shown that FIMPs achieved good photothermal conversion efficiency, promoted the generation of oxygen and reactive oxygen species (ROS), and thus effectively killed tumor cells. In vivo studies indicated that FIMPs effectively overcome the hypoxic microenvironment within tumors and significantly inhibit tumor growth with good biocompatibility. The rationally designed oxygen- and bubble-generating polymersomes have great potential to overcome the tumor hypoxia limitations for enhancing the photothermal-photodynamic combination therapeutic effect.

Combined anti-hepatocellular carcinoma therapy inhibit drug-resistance and metastasis via targeting "substance P-hepatic stellate cells-hepatocellular carcinoma" axis

Peripheral nerves have emerged as the important components in tumor microenvironment (TME), which could activate hepatic stellate cells (HSCs) by secreting substance P (SP), leading to hepatocellular carcinoma (HCC) invasion and metastasis. Herein, we proposed a novel anti-HCC concept of blocking "SP-HSCs-HCC" axis for omnidirectional inhibition of HCC development. To pursue this aim, the novel CAP/GA-sHA-DOX NPs were developed for targeted co-delivery of capsaicin (CAP) and doxorubicin (DOX) using glycyrrhetinic acid (GA) modified sulfated-HA (sHA) as nanocarriers. Among that, CAP could inhibit the activation of HSCs as an inhibitor of SP. Notably, to real mimic "SP-HSCs-HCC" axis for in vitro and in vivo evaluation, both "SP + LX-2+BEL-7402" co-cultured cell model and "SP + m-HSC + H22" co-implantation mice model were attempted for the first time. Furthermore, in vivo anti-HCC effects were performed in three different tumor-bearing models: subcutaneous implantation of H22 or "SP + m-HSC + H22", intravenous injection of H22 for lung metastasis, and orthotopic implantation of H22 for primary HCC. Our results showed that CAP/GA-sHA-DOX NPs could be efficiently taken up by tumor cells and activated HSCs (aHSCs) simultaneously, and effectively inhibit tumor drug-resistance and migration by blocking SP-induced HSCs activation. In addition, CAP/GA-sHA-DOX NPs exhibited low ECM deposition, less tumor angiogenesis, and superior in vivo anti-HCC effects. The anti-HCC mechanisms revealed that CAP/GA-sHA-DOX NPs could down-regulate the expression level of Vimentin and P-gp, reverse epithelial-mesenchymal transition (EMT) of tumor cells. In brief, the nano-sized combination therapy based on GA-sHA-DOX polymers could effectively inhibit drug-resistance and metastasis of HCC by blocking "SP-HSCs-HCC" axis, which provides a promising approach for cancer therapy.

Polymer-Based Dual-Responsive Self-Emulsifying Nanodroplets as Potential Carriers for Poorly Soluble Drugs

A biodegradable amphiphilic liquid polymer was designed to form self-emulsifying nanodroplets in water for delivering poorly soluble drugs. The polymer was composed of multiple short blocks of poly(ethylene glycol) (PEG) and poly(caprolactone) (PCL) connected through acid-labile acetal linkages. With an overall average molecular weight of over 18 kDa, the polymer remained as a viscous liquid under room and physiological temperatures. Dispersing the polymer in an aqueous buffer gave rise to highly stable micelle-like nanodroplets with an average size of approximately 15-20 nm. The nanodroplet dispersions underwent reversible temperature-sensitive aggregation with cloud points ranging from 45 to 50 °C, depending on polymer concentration. Nuclear magnetic resonance (NMR) and dynamic light scattering analyses revealed that while the nanodroplets were stable at pH 7.4 for several days, hydrolysis of the acetal linkages in the polymer backbone was much accelerated under mildly acidic pH 5.0, resulting in the formation of large microdroplets. Nile red (NR), a poorly water-soluble fluorophore, can be solubilized in the nanodroplets, and efficient intracellular delivery of NR was achieved. The hydrophobic indocyanine green (ICG) was also encapsulated in the nanodroplets. Near-infrared (NIR) fluorescence imaging and in vivo biocompatibility of the ICG-loaded nanodroplets were demonstrated in mice. In summary, the self-emulsifying nanodroplets of amphiphilic liquid polymer would be a promising material system for poorly soluble drug delivery and imaging in vivo.

pH-sensitive and bubble-generating mesoporous silica-based nanoparticles for enhanced tumor combination therapy

Chemotherapy has been a major option in clinic treatment of malignant tumors. However, single chemotherapy faces some drawbacks, such as multidrug resistance, severe side effects, which hinder its clinic application in tumor treatment. Multifunctional nanoparticles loading with chemotherapeutic agent and photosensitizer could be a promising way to efficiently conduct tumor combination therapy. In the current study, a novel pH-sensitive and bubble-generating mesoporous silica-based drug delivery system (denoted as M(a)D@PI-PEG-RGD) was constructed. Ammonium bicarbonate (NH₄HCO₃; abc) and chemotherapeutic agent doxorubicin (DOX) were loaded into the pores of mesoporous silica. Indocyanine green (ICG) as a photothermal and photodynamic agent was loaded onto the polydopamine (PDA) layer surface. The synthesized nanoparticles displayed a narrow polydispersity (PDI) and small particle size as characterized through dynamic light scattering-autosizer analysis. The nanoparticles also showed high targeting efficacy through RGD modification as indicated by cellular uptake and animal studies. DOX release analysis confirmed that the nanoparticles were pH-dependent and that NH₄HCO₃ accelerated drug release. At the same time, the nanoparticles had obvious photothermal and photodynamic effects performed by ICG which restrained tumor growth remarkably. In summary, the multifunctional nanoparticles presented a promising system for combination therapy.

Photothermal/matrix metalloproteinase-2 dual-responsive gelatin nanoparticles for breast cancer treatment

The chemotherapy combined with photothermal therapy has been a favorable approach for the treatment of breast cancer. In present study, nanoparticles with the characteristics of photothermal/matrix metalloproteinase-2 (MMP-2) dual-responsive, tumor targeting, and size-variability were designed for enhancing the antitumor efficacy and achieving "on-demand" drug release markedly. Based on the thermal sensitivity of gelatin, we designed a size-variable gelatin nanoparticle (GNP) to encapsulate indocyanine green (ICG) and doxorubicin (DOX). Under an 808 nm laser irradiation, GNP-DOX/ICG responded photothermally and swelled in size from 71.58 ± 4.28 to 160.80 ± 9.51 nm, which was beneficial for particle retention in the tumor sites and release of the loaded therapeutics. Additionally, GNP-DOX/ICG showed a size reduction of the particles to 33.24 ± 4.11 nm and further improved drug release with the degradation of overexpressed MMP-2 in tumor. In the subsequently performed in vitro experiments, it was confirmed that GNP-DOX/ICG could provide a therapeutic effect that was enhanced and synergistic. Consequently, GNP-DOX/ICG could efficiently suppress the growth of 4T1 tumor in vivo. In conclusion, this study may provide a promising strategy in the rational design of drug delivery nanosystems based on gelatin for chemo-photothermal therapy to achieve synergistically enhanced therapeutic efficacy against breast cancer.

Liposome mimicking polymersomes; A comparative study of the merits of polymersomes in terms of formulation and stability

The past few decades have seen a significant rise in research into alternative polymer based nanosized unilamellar drug delivery systems, termed polymersomes. The reported benefits of polymersomes over the more traditional liposomes include increased stability, higher encapsulation efficacies, better adaptability and reduced water permeation due to an increased bilayer thickness. Together, these advantages render them suitable for a plethora of therapies. The work presented in this manuscript creates and compares four such drug delivery systems, two based on the traditional liposome and two prepared from amphiphilic polymers. From there we assess these systems in terms of size, stability, encapsulation efficiency, drug release, cellular toxicity and cellular uptake. We can confirm from this comprehensive investigation that the multi-functional synthetic polymersomes are undoubtedly a future contender in this expanding field of nanomedicines. Their ability to encapsulate a cocktail of different compounds, high stability as well as their ease of adaptability will ensure that they feature prominently in the future of advanced drug delivery systems.

Gas-generating mesoporous silica nanoparticles with rapid localized drug release for enhanced chemophotothermal tumor therapy

Chemophotothermal combination therapy has emerged as a novel and promising strategy to treat cancer. To improve anticancer effectiveness and reduce systemic toxicity, it is essential to trigger drug release at tumor sites or within tumor cells for maximal drug exposure. Herein, we constructed gas-generating mesoporous silica nanoparticles (MSNs) that can load ammonium bicarbonate (ABC) and doxorubicin (DOX) within the pores, encapsulate indocyanine green (ICG) onto the polydopamine (PDA) layer, and modify the RGD peptide on the outer surface [denoted as M(abc)-DOX@PDA-ICG-PEG-RGD] for triggered drug release and targeted chemophotothermal combination therapy. Upon hyperthermia or low pH value, the encapsulated ABC can efficiently generate CO₂ gas, thus enhancing the damage to the PDA layer and accelerating DOX release. In vitro experiments showed that the M(abc)-DOX@PDA-ICG-PEG-RGD significantly enhanced cellular uptake and cytotoxicity, and laser irradiation further increased the endocytic and cytotoxic effects. An in vivo study indicated that the nanoparticles can effectively accumulate at the tumor site and significantly inhibited tumor growth with no side-effects to the normal organs. Thus, this gas-generating MSN-based nanocarrier that can trigger drug release in response to laser irradiation or low pH value holds great potential in enhancing cancer chemophotothermal combination therapy.

Supramolecular Loading of a Broad Spectrum of Molecular Guests In Hyperbranched Polytriazole Nanoparticles with Cores Containing Multiple Functional Groups

This study evaluated the supramolecular properties of a new family of water-soluble hyperbranched polytriazoles that have a unimolecular micelle structure. Two new, structurally related hyperbranched polymers (HBPa and HBPn), with the same size (D_h = 11 nm) and core-shell architecture, were prepared and found to act as nanoscale hosts for a broad spectrum of molecular guests. The globular-shaped hyperbranched polymers were synthesized by a straightforward one-pot polymerization method that permits easy synthetic control of the multiple functional groups within the core. Surrounding the core is a shell of polyethylene glycol chains that promotes solubility in pH 7.4 buffer solution and inhibits self-aggregation of the nanoparticles. The core of HBPa, containing a mixture of anionic carboxylate groups and 1,2,3-triazole rings, could be loaded with cationic hydrophilic (i.e., propidium iodide) or partially hydrophobic (i.e., Hoechst 33342) dyes or drugs, including a binary dye/drug pair (i.e., indocyanine green/mitoxantrone). The core of HBPn, containing a mixture of uncharged 2-pentanone chains and 1,2,3-triazole rings, could be loaded with uncharged and very hydrophobic dyes (i.e., Nile Red) or drugs. Improved aqueous solubility of camptothecin was achieved 10-fold from 8.4 to 75 ng/mL. Additionally, cell toxicity studies showed that HBPn was able to release the camptothecin drug inside A549 cancer cells resulting in increased cell death. Taken together, the results suggest that this new family of water-soluble hyperbranched polytriazoles could be broadly useful as nanocarriers for various applications in therapy, imaging, or a combination of the two (theranostics).

Rational design and latest advances of codelivery systems for cancer therapy

Current treatments have limited effectiveness in treating tumors. The combination of multiple drugs or treatment strategies is widely studied to improve therapeutic effect and reduce adverse effects of cancer therapy. The codelivery system is the key to realize combined therapies. It is necessary to design and construct different codelivery systems in accordance with the variable structures and properties of cargoes and vectors. This review presented the typical design considerations about codelivery vectors for cancer therapy and described the current state of codelivery systems from two aspects: different types of vectors and collaborative treatment strategies. The commonly used loading methods of cargoes into the vectors, including physical and chemical processes, are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of codelivery systems.

Liver-Targeting and pH-Sensitive Sulfated Hyaluronic Acid Mixed Micelles for Hepatoma Therapy

Background

The tumor-targeting ability and pH-sensitive properties of intelligent drug delivery systems are crucial for effective drug delivery and anti-tumor therapy.

Methods

In this study, sHA-DOX/HA-GA mixed micelles were designed with the following properties: sulfated hyaluronic acid (sHA) was synthesized to block cell migration by inhibiting HAase; sHA-DOX conjugates were synthesized via pH-sensitive hydrazone bond to realize DOX-sensitive release. The introduction of HA-GA conjugate could improve active-targeting ability and cellular uptake.

Results

The results showed that the mixed micelles possessed a nearly spherical shape, nanoscale particle size (217.70±0.89 nm), narrow size distribution (PDI=0.07±0.04), negative zeta potential (-31.87±0.61 mV) and pH-dependent DOX release. In addition, the sHA-DOX/HA-GA micelles exhibited concentration-dependent cytotoxicities against liver carcinoma cells (HepG2) and HeLa cells, and were shown to be effectively taken up by HepG2 cells by confocal microscopy analysis. Furthermore, the in vivo anti-tumor study showed that mixed micelles had a superior anti-tumor effect compared to that of free DOX. Further evidence obtained from the hematoxylin-eosin staining and immunohistochemistry analysis also demonstrated that sHA-DOX/HA-GA exhibited stronger tumor inhibition and lower systemic toxicity than free DOX.

Conclusion

The sHA-DOX/HA-GA mixed micelles could be a potential drug delivery system for anti-hepatoma therapy.

A Dual-Model Imaging Theragnostic System Based on Mesoporous Silica Nanoparticles for Enhanced Cancer Phototherapy

Mesoporous silica nanoparticles (MSNs) show great promise to be exploited as versatile multifunctional nanocarriers for effective cancer diagnosis and treatment. In this work, perfluorohexane (PFH)-encapsulated MSNs with indocyanine green (ICG)-polydopamine (PDA) layer and poly(ethylene glycol)-folic acid coating (designated as MSNs-PFH@PDA-ICG-PEG-FA) are successfully fabricated to achieve tumor ultrasonic (US)/near-infrared fluorescence (NIRF) imaging as well as photothermal therapy (PTT)/photodynamic therapy (PDT). MSNs-PFH@PDA-ICG-PEG-FA exhibits good monodispersity with high ICG loading, significantly enhances ICG photostability, and greatly improves cellular uptake. Upon single 808 nm NIR irradiation, the nanocarrier not only efficiently generates hyperthermia to realize PTT, but also produces reactive oxygen species (ROS) for effective PDT. Meanwhile, NIR irradiation can trigger PFH to undergo vaporization and provide a super-resolution US image. Thus, the PTT/PDT combination therapy can be dually guided by PFH-induced US imaging and ICG-induced NIRF imaging. In vivo antitumor studies demonstrate that PTT/PDT from MSNs-PFH@PDA-ICG-PEG-FA significantly inhibits tumor growth and achieves a cure rate of 60% (three out of five mice are completely cured). Hence, the multifunctional MSNs appear to be a promising theragnostic nanoplatform for multimodal cancer imaging and therapy.

Polypyrrole-coated phase-change liquid perfluorocarbon nanoparticles for the visualized photothermal-chemotherapy of breast cancer

A theranostic nanoplatform (DTX/PFH@PPy-FA) for multi-modal imaging-guided photothermal-chemotherapy has been constructed. Lipid-perfluorohexane (PFH) nanodroplet loaded with docetaxel (DTX) was coated with a polypyrrole (PPy) shell. Then the folic acid (FA) molecule with active tumor-targeting function was modified on the surface of PPy shell. Due to the good photothermal conversion performance, PPy shell can raise the temperature under the near infrared laser irradiation, which not only produces photothermal effect to kill tumor cells, but also promotes liquid-gas phase change of PFH, and produces ultrasound imaging effect. The results of photothermal experiment and imaging experiment confirmed that the obtained DTX/PFH@PPy-FA possessed good photothermal, photoacoustic imaging and ultrasound imaging effects in vitro and in vivo. The results of in vitro cell experiments showed that DTX/PFH@PPy-FA had a active targeting ability to tumor cells, and its photothermal-chemotherapy synergistically inhibited the proliferation of tumor cells. In vivo study on 4T1-bearing BALB/c mice indicated that the photothermal-chemotherapy of DTX/PFH@PPy-FA not only effectively inhibited the growth of 4T1 breast cancer, but also inhibited lung metastasis. This multifunctional nanoparticle is expected to become a new nanoplatform for the visualized photothermal-chemotherapy of cancer. STATEMENT OF SIGNIFICANCE: In this work, we presented a multi-modal imaging-guided photothermal-chemotherapy theranostic nanoplatform (DTX/PFH@PPy-FA) for visualized treatment of breast cancer. The docetaxel (DTX) loaded perfluorohexane (PFH) nanodroplets (DTX/PFH@SPC) were firstly prepared and then coated with polypyrrole shell (PPy). Then, PEGylated folic acid was covalently modified to obtain the folate-targeted multifunctional nanoparticle (DTX/PFH@PPy-FA). Due to the good photothermal conversion performance, PPy shell can raise the temperature under the near infrared laser irradiation, which not only produces photothermal effect to kill tumor cells, but also promotes liquid-gas phase change of PFH, and produces good ultrasound imaging effect. The PPy shell also imparts photoacoustic imaging characteristics to the nanoparticles. Experimental results show that our prepared DTX/PFH@PPy-FA possesses folic acid-mediated tumor targeting ability, ultrasound and photoacoustic imaging, and photothermal-chemotherapy synergistic effect. This multi-functional nanoparticle is expected to become a new platform for the visualized photothermal-chemotherapy of breast cancer.

Zwitterionic polypeptide nanomedicine with dual NIR/reduction-responsivity for synergistic cancer photothermal-chemotherapy

Dual NIR/reduction-responsive and zwitterionic polypeptide nanoparticles of PMC/DOX-ICG were fabricated, which achieved in vivo NIR fluorescence imaging and synergistic cancer PTT-CT treatment, and effectively ablated the HeLa tumors without recurrence for 30 days.

Poly(d,l-lactic-co-glycolic acid) (PLGA) hollow fiber with segmental switchability of its chains sensitive to NIR light for synergistic cancer therapy

This work introduces a new fibrous system for synergistic cancer therapy. The system consists of poly(d,l-lactic-co-glycolic acid) (PLGA) fibers with a core encapsulating an anticancer drug and a shell entrapping gold nanorods (AuNRs) as a photothermal agent. On exposure to NIR light, the photothermal agent generates heat to raise the local temperature of the fibers. If the temperature is above a glass transition (T_g) of the polymer, the polymer chains will be mobile, increasing free volume in size within the shell. As a result, a rapid release of the drug can be achieved. When NIR light is turned off, the release will stop with inactivity of the photothermal agent, followed by freezing the segmental motion of the polymer chains. The on-off switching of NIR light in a time-controllable manner allows a repeated and accurate release of the drug, leading to the significant enhancement of anticancer activity in combination with the hyperthermia effect arising from the photothermal agent.

Nucleus-Targeted, Echogenic Polymersomes for Delivering a Cancer Stemness Inhibitor to Pancreatic Cancer Cells

Chemotherapeutic agents for treating cancers show considerable side effects, toxicity, and drug resistance. To mitigate the problems, we designed nucleus-targeted, echogenic, stimuli-responsive polymeric vesicles (polymersomes) to transport and subsequently release the encapsulated anticancer drugs within the nuclei of pancreatic cancer cells. We synthesized an alkyne-dexamethasone derivative and conjugated it to N₃-polyethylene glycol (PEG)-polylactic acid (PLA) copolymer employing the Cu²⁺ catalyzed "Click" reaction. We prepared polymersomes from the dexamethasone-PEG-PLA conjugate along with a synthesized stimuli-responsive polymer PEG-S-S-PLA. The dexamethasone group dilates the nuclear pore complexes and transports the vesicles to the nuclei. We designed the polymersomes to release the encapsulated drugs in the presence of a high concentration of reducing agents in the nuclei of pancreatic cancer cells. We observed that the nucleus-targeted, stimuli-responsive polymersomes released 70% of encapsulated contents in the nucleus-mimicking environment in 80 min. We encapsulated the cancer stemness inhibitor BBI608 in the vesicles and observed that the BBI608 encapsulated polymersomes reduced the viability of the BxPC3 cells to 43% in three-dimensional spheroid cultures. The polymersomes were prepared following a special protocol so that they scatter ultrasound, allowing imaging by a medical ultrasound scanner. Therefore, these echogenic, targeted, stimuli-responsive, and drug-encapsulated polymersomes have the potential for trackable, targeted carrier of chemotherapeutic drugs to cancer cell nuclei.