Single-Stimulus Dual-Drug Sensitive Nanoplatform for Enhanced Photoactivated Therapy

The Application of Nanoparticle-Based Imaging and Phototherapy for Female Reproductive Organs Diseases

Various female reproductive disorders affect millions of women worldwide and bring many troubles to women's daily life. Let alone, gynecological cancer (such as ovarian cancer and cervical cancer) is a severe threat to most women's lives. Endometriosis, pelvic inflammatory disease, and other chronic diseases-induced pain have significantly harmed women's physical and mental health. Despite recent advances in the female reproductive field, the existing challenges are still enormous such as personalization of disease, difficulty in diagnosing early cancers, antibiotic resistance in infectious diseases, etc. To confront such challenges, nanoparticle-based imaging tools and phototherapies that offer minimally invasive detection and treatment of reproductive tract-associated pathologies are indispensable and innovative. Of late, several clinical trials have also been conducted using nanoparticles for the early detection of female reproductive tract infections and cancers, targeted drug delivery, and cellular therapeutics. However, these nanoparticle trials are still nascent due to the body's delicate and complex female reproductive system. The present review comprehensively focuses on emerging nanoparticle-based imaging and phototherapies applications, which hold enormous promise for improved early diagnosis and effective treatments of various female reproductive organ diseases.

Microfluidic preparation and optimization of (Kollicoat ® IR-b-PCL) polymersome for co-delivery of Nisin-Curcumin in breast cancer application

This work aimed to develop amphiphilic nanocarriers such as polymersome based diblock copolymer of Kollicoat ® IR -block-poly(ε-caprolactone) (Kollicoat ® IR-b-PCL) for potential co-delivery of Nisin (Ni) and Curcumin (CUR) for treatment of breast cancer. To generate multi-layered nanocarriers of uniform size and morphology, microfluidics was used as a new technology. In order to characterise and optimize polymersome, design of experiments (Design-Expert) software with three levels full factorial design (3-FFD) method was used. Finally, the optimized polymersome was produced with a spherical morphology, small particle size (dH < 200 nm), uniform size distribution (PDI < 0.2), and high drug loading efficiency (Ni 78 % and CUR 93 %). Furthermore, the maximum release of Ni and CUR was found to be roughly 60 % and 80 % in PBS, respectively. Cytotoxicity assays showed a slight cytotoxicity of Ni and CUR -loaded polymersome (N- Ni /CUR) towards normal cells while demonstrating inhibitory activity against cancer cells compared to the free drugs. Also, the apoptosis assays and cellular uptake confirmed the obtained results from cytotoxic analysis. In general, this study demonstrated a microfluidic approach for preparation and optimization of polymersome for co-delivery of two drugs into cancer cells.

Reductive prodrug and AIE copolymer nanoparticle for monitoring and chemotherapy

Polymeric micelle systems for drug delivery, monitor and chemotherapy have gained significant attention, and reductive polymeric micelle systems have become particularly attractive due to their controlled release behavior without additional assistance. However, there are challenges in accurately controlling drug and probe release from the nanoparticles and determining the loading content of drug and probe. To address these issues, we have developed a reduction-responsive Pt(IV) prodrug-based polymeric delivery system that can be dynamically monitored using aggregation-induced emission luminogens (AIE) based bioprobes. These polymeric micelle can self-assemble into nanoparticles and release both bio-active Pt(II) drug and bio-probe upon reduction activation. TPE molecules released in the inner endo/lysosomal microenvironment aggregate and fluoresce upon irradiation, thus allowing real-time tracking of drug biodistribution without additional contrast agents. Advantages of this system include position-specific chemical bond cleavage, control of platinum content, and monitoring of drug reduction and biodistribution.

Polysaccharide‑platinum complexes for cancer theranostics

Platinum anticancer drugs have been explored and developed in recent years to reduce systematic toxicities and resist drug resistance. Polysaccharides derived from nature have abundant structures as well as pharmacological activities. The review provides insights on the design, synthesis, characterization and associating therapeutic application of platinum complexes with polysaccharides that are classified by electronic charge. The complexes give birth to multifunctional properties with enhanced drug accumulation, improved tumor selectivity and achieved synergistic antitumor effect in cancer therapy. Several techniques developing polysaccharides-based carriers newly are also discussed. Moreover, the lasted immunoregulatory activities of innate immune reactions triggered by polysaccharides are summarized. Finally, we discuss the current shortcomings and outline potential strategies for improving platinum-based personalized cancer treatment. Using platinum-polysaccharides complexes for improving the immunotherapy efficiency represents a promising framework in future.

Review on Metal-Based Theranostic Nanoparticles for Cancer Therapy and Imaging

Theranostic agents are promising due to their ability to diagnose, treat and monitor different types of cancer using a variety of imaging modalities. The advantage specifically of nanoparticles is that they can accumulate easily at the tumor site due to the large gaps in blood vessels near tumors. Such high concentration of theranostic agents at the target site can lead to enhancement in both imaging and therapy. This article provides an overview of nanoparticles that have been used for cancer theranostics, and the different imaging, treatment options and signaling pathways that are important when using nanoparticles for cancer theranostics. In particular, nanoparticles made of metal elements are emphasized due to their wide applications in cancer theranostics. One important aspect discussed is the ability to combine different types of metals in one nanoplatform for use as multimodal imaging and therapeutic agents for cancer.

Dual-sensitive dual-prodrug nanoparticles with light-controlled endo/lysosomal escape for synergistic photoactivated chemotherapy

The clinical application of conventional chemotherapeutic agents, represented by cisplatin, is limited by severe side effects. So, it is essential to explore more safer and controlled drug delivery systems for synergistic chemotherapy. In this work, we designed dual-sensitive dual-prodrug nanoparticles (DDNPs) for photoactivated platinum-based synergistic chemotherapy. With photosensitivity, DDNPs could be photoactivated from inert Pt(IV) to toxic Pt(II) under safe UVA light in a spatiotemporally controlled manner. Concurrently, mild could be generated from DDNPs to assist the endo/lysosomal escape of DDNPs for better photoactivated chemotherapy (PACT). Furthermore, with acid-sensitivity, demethylcantharidin (DMC), a protein phosphatase 2A (PP2A) inhibitor, was released to block the DNA repair pathway and thereby could sensitize platinum-based chemotherapy in intracellular acidic microenvironments. Along with a precise ratio (Pt : DMC = 1 : 2), DDNPs had a powerful synergistic anti-cancer effect in vitro and in vivo. In the future, DDNPs have great potential as a safe and multifunctional drug delivery system for precise nanomedicine in clinical treatments.

Nanoparticulation of Prodrug into Medicines for Cancer Therapy

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Nano-assembly of ursolic acid with platinum prodrug overcomes multiple deactivation pathways in platinum-resistant ovarian cancer

As the most common cause of gynecological cancer-related deaths worldwide, ovarian cancer requires novel therapy strategies. Pt(ii)-Based antitumor drugs (e.g. cisplatin) are one of the most successful and frequently used drugs in ovarian cancer chemotherapy at present. However, drug resistance and severe side effects are the major problems in cancer treatment. Herein, the design of a reduction responsive platinum(iv) (Pt(iv))/ursolic acid (UA)/polyethylene glycol (PEG) dual prodrug amphiphile (Pt(iv)-UA-PEG) to treat cisplatin-resistant ovarian cancer is reported for the first time. Pt(iv)-UA-PEG could self-assemble into nanoparticles (Pt(iv)-UA NPs) with a fixed and precise Pt/UA ratio, and a constantly high content of drugs. Pt(iv)-UA NPs could be efficiently taken up by cisplatin-resistant ovarian cancer cells and release the drug in intracellular reductive and acidic environments. In vitro studies show that the released UA and cisplatin have different anticancer mechanisms, and their synergistic effects overcome the detoxification and anti-apoptotic mechanisms of cancer cells. Furthermore, the in vivo results indicate that Pt(iv)-UA NPs have a prolonged blood circulation time, enhanced tumor accumulation, and significantly improved antitumor efficacy in A2780/DDP tumor-bearing mice, without causing any side effects. In summary, our results demonstrate that the development of the stimuli-responsive dual prodrug amphiphile nano-assembly provides a new strategy to overcome drug resistance.

Photoresponsive metallopolymer nanoparticles for cancer theranostics

Over the past decades, transition metal complexes have been successfully used in anticancer phototherapies. They have shown promising properties in many different areas including photo-induced ligand exchange or release, rich excited state behavior, and versatile biochemical properties. When encorporated into polymeric frameworks and become part of nanostructures, photoresponsive metallopolymer nanoparticles (MPNs) show enhanced water solubility, extended blood circulation and increased tumor-specific accumulation, which greatly improves the tumor therapeutic effects compared to low-molecule-weight metal complexes. In this review, we aim to present the recent development of photoresponsive MPNs as therapeutic nanomedicines. This review will summarize four major areas separately, namely platinum-containing polymers, zinc-containing polymers, iridium-containing polymers and ruthenium-containing polymers. Representative MPNs of each type are discussed in terms of their design strategies, fabrication methods, and working mechanisms. Current challenges and future perspectives in this field are also highlighted.

An improved method in fabrication of smart dual-responsive nanogels for controlled release of doxorubicin and curcumin in HT-29 colon cancer cells

The combination therapy which has been proposed as the strategy for the cancer treatment could achieve a synergistic effect for cancer therapies and reduce the dosage of the applied drugs. On account of the the unique properties as the high absorbed water content, biocompatibility, and flexibility, the targeting nanogels have been considred as a suitable platform. Herein, a non-toxic pH/thermo-responsive hydrogel P(NIPAAm-co-DMAEMA) was synthesized and characterized through the free-radical polymerization and expanded upon an easy process for the preparation of the smart responsive nanogels; that is, the nanogels were used for the efficient and controlled delivery of the anti-cancer drug doxorubicin (DOX) and chemosensitizer curcumin (CUR) simultaneously like a promising strategy for the cancer treatment. The size of the nanogels, which were made, was about 70 nm which is relatively optimal for the enhanced permeability and retention (EPR) effects. The DOX and CUR co-loaded nanocarriers were prepared by the high encapsulation efficiency (EE). It is important to mention that the controlled drug release behavior of the nanocarriers was also investigated. An enhanced ability of DOX and CUR-loaded nanoformulation to induce the cell apoptosis in the HT-29 colon cancer cells which represented the greater antitumor efficacy than the single-drug formulations or free drugs was resulted through the In vitro cytotoxicity. Overall, according to the data, the simultaneous delivery of the dual drugs through the fabricated nanogels could synergistically potentiate the antitumor effects on the colon cancer (CC).

Synthesis, characterization and photodynamic activity of half-sandwich rhodium(III) complexes with curcuminoids

Half-sandwich Cp*-Rh complexes containing curcuminoids ([Rh(η⁵-Cp*)(L)(Py)]PF₆, 1-3, L = curcuminoid ligands L¹-L³) were prepared, characterized and studied for anticancer activity. Complex 1 was structurally characterized by single-crystal X-ray crystallography. Complex 3 presented excellent photodynamic anticancer effect in light (>400 nm) showing IC₅₀ values of 7.5 and 4.3 μM against HepG2, SKOV3 and HeLa, respectively, along with the 12.4, 7.9 and 4.7-fold lower toxicity in the dark. Confocal fluorescence images show that the complex primarily targeted mitochondrial localization. These results suggest that the complex 3 was a valuable agent with higher efficacy for chemotherapy and photodynamic therapy, which can achieve real-time image guidance in cancer therapy for the fluorescence of the complex as imaging signals. This investigation provides a valuable route to design novel half-sandwich Cp*-Rh complexes with higher efficacy for photodynamic anticancer chemotherapy.

Photoactivatable Platinum-Based Anticancer Drugs: Mode of Photoactivation and Mechanism of Action

Platinum-based anticancer drugs are a class of widely used agents in clinical cancer treatment. However, their efficacy was greatly limited by their severe side effects and the arising drug resistance. The selective activation of inert platinum-based drugs in the tumor site by light irradiation is able to reduce side effects, and the novel mechanism of action of photoactivatable platinum drugs might also conquer the resistance. In this review, the recent advances in the design of photoactivatable platinum-based drugs were summarized. The complexes are classified according to their mode of action, including photoreduction, photo-uncaging, and photodissociation. The rationale of drug design, dark stability, photoactivation process, cytotoxicity, and mechanism of action of typical photoactivatable platinum drugs were reviewed. Finally, the challenges and opportunities for designing more potent photoactivatable platinum drugs were discussed.

Lysine-embedded cellulose-based nanosystem for efficient dual-delivery of chemotherapeutics in combination cancer therapy

Combination therapy by two or multiple drugs with different mechanisms of action is a promising strategy in cancer treatment. In this regard, a wide range of chemotherapeutics has used simultaneously to achieve the synergistic effect and overcome the adverse side effects of single-drug therapy. Herein, we developed a biocompatible nanoparticle-based system composed of nanocrystalline cellulose (NCC) and amino acid l-lysine for efficient co-delivery of model chemotherapeutic methotrexate (MTX) and polyphenol compound curcumin (CUR) to the MCF-7 and MDA-MB-231 cells. The drugs could release in a sustained and acidic-facilitate manner. In vitro cytotoxicity results represented the superior anti-tumor efficacy of the dual-drug-loaded nanocarriers. Possible inhibition of cell growth and induction of apoptosis in the cells treated with different formulations of CUR and MTX were explored by cell cycle analysis and DAPI staining. Overall, the engineered nanosystem can be used as suitable candidates to achieve efficient multi-drug delivery for combination cancer therapy.

Photoactivatable Prodrug-Backboned Polymeric Nanoparticles for Efficient Light-Controlled Gene Delivery and Synergistic Treatment of Platinum-Resistant Ovarian Cancer

Combination of chemotherapy and gene therapy provides an effective strategy for cancer treatment. However, the lack of suitable codelivery systems with efficient endo/lysosomal escape and controllable drug release/gene unpacking is the major bottleneck for maximizing the combinational therapeutic efficacy. In this work, we developed a photoactivatable Pt(IV) prodrug-backboned polymeric nanoparticle system (CNP_{PtCP/si(c-fos)}) for light-controlled si(c-fos) delivery and synergistic photoactivated chemotherapy (PACT) and RNA interference (RNAi) on platinum-resistant ovarian cancer (PROC). Upon blue-light irradiation (430 nm), CNP_{PtCP/si(c-fos)} generates oxygen-independent N₃^• with mild oxidation energy for efficient endo/lysosomal escape through N₃^•-assisted photochemical internalization with less gene deactivation. Thereafter, along with Pt(IV) prodrug activation, CNP_{PtCP/si(c-fos)} dissociates to release active Pt(II) and unpack si(c-fos) simultaneously. Both in vitro and in vivo results demonstrated that CNP_{PtCP/si(c-fos)} displayed excellent synergistic therapeutic efficacy on PROC with low toxicity. This PACT prodrug-backboned polymeric nanoplatform may provide a promising gene/drug codelivery tactic for treatment of various hard-to-tackle cancers.

Morphology tunable and acid-sensitive dextran-doxorubicin conjugate assemblies for targeted cancer therapy

Stimuli-responsive and targetable nanomedicine systems have been widely applied as effective modalities for drug delivery and tumor therapeutics. Particle shape is also important for the biodistribution and cellular uptake in drug delivery applications. Here, morphology tunable and acid-responsive dextran-doxorubicin conjugate assemblies of DD-M and DDF-V for targeted doxorubicin (DOX) delivery were constructed, which contain the following favorable advantages: (1) one-pot synthesis of the drug loaded system with a Schiff base reaction is a green chemistry method which is better than the conventional drug conjugation/encapsulation methods. (2) The morphology of the nanoparticles could be regulated from a micelle (DD-M) to vesicle (DDF-V) structure by either introducing folic acid (FA) or not. (3) The abundant hydroxyl groups and electronegativity give DD-M and DDF-V superior stability in the physiological environment. (4) Besides, the multifunctional DDF-V with its important merits including tumor-targeting ability and acid-responsiveness is specific for DOX delivery in cancer therapy. (5) Compared to free DOX and DD-M, DDF-V displayed enhanced anti-tumor efficacy both in vitro and in vivo without obvious systematic toxicity. The morphology tunable, acid-sensitive and targetable nanosystem could be a promising strategy for site-specific drug delivery and potential cancer therapy in the future.

Near-infrared-emitting AIE multinuclear cationic Ir(iii) complex-assembled nanoparticles for photodynamic therapy

The first pure NIR-emitting AIE multinuclear Ir(iii) complex NPs obtained by self-assembly exhibit excellent cell imaging and PDT performance.

Intelligent nanoflowers: a full tumor microenvironment-responsive multimodal cancer theranostic nanoplatform

Although the collaborative therapy of chemotherapy (CT) and photodynamic therapy (PDT) is much more efficient for tumor treatment than monotherapies, premature leakage of drugs from nanocarriers and hypoxia in the tumor microenvironment (TME) result in systemic toxicity and suboptimal therapy efficiency. To overcome these limitations, we developed an intelligent nanoflower composite (termed FHCPC@MnO2) by coating functionalized polyphosphazene on superparamagnetic Fe3O4 nanoclusters and then growing MnO2 nanosheets as an outer shell. The FHCPC@MnO2 nanoflowers with multistage H2O2/pH/GSH-responsive properties could fully exploit TME characteristics, including supernormal glutathione (GSH) levels, low pH and high H2O2, to realize the specific release of drugs in tumors and maximum synergetic therapeutic effects. The MnO2 nanosheets can elevate O2 concentration by catalytic decomposition of H2O2 and can be simultaneously reduced to Mn2+ by overexpressed GSH in the acidic TME. Meanwhile, the inner polyphosphazene containing (bis-(4-hydroxyphenyl)-disulfide) is GSH- and pH-sensitively biodegradable to release the anticancer drug curcumin (CUR) and photosensitizer chlorin e6 (Ce6) in the TME. Therefore, the "triple-responsive" and synergetic strategy simultaneously endows the nanoflowers with specific drug release, relieving hypoxia and the antioxidant capability of the tumor and achieving significant optimization of CT and PDT. In addition, the resulting Mn2+ ions and Fe3O4 core enable in vivo T1/T2 magnetic resonance imaging (MRI), while the released Ce6 can simultaneously provide a fluorescence imaging (FL) function. Unsurprisingly, the intelligent nanoflowers exhibited remarkable multimodal theranostic performance both in vitro and in vivo, suggesting their great potential for precision medicine.

Light-activatable dual prodrug polymer nanoparticle for precise synergistic chemotherapy guided by drug-mediated computed tomography imaging

The synergistic efficacy and clinical application of light-responsive polymeric co-delivery systems are severely restricted by uncontrollable/imprecise drug loading, release, and adverse effects caused by the introduction of additional light-responsive molecules or contrast agents when diagnostic imaging is applied to guide therapy. Here, we report the design of a light-activatable dual prodrug polymer nanoparticle (DPP NP) for precise synergistic chemotherapy guided by drug-mediated computed tomography (DMCT) imaging without the introduction of any additional diagnostic imaging agent. DPP NP enables visible light-triggered prodrug polymer backbone cleavage and bioactive Pt(II) release in cancer cell/tumor site; the light-cleaved polymer fragments are further hydrolyzed to produce demethyl cantharidin (DMC). Notably, the drug loading ratio of Pt(IV) and DMC in DPP NP was fixed at an optimal value to achieve maximum synergistic cancer cell killing, which was kept even after cellular uptake, thereby resulting in enhanced synergistic antitumor efficacy both in vitro and in vivo. Because of the high content of the heavy metal Pt in the polymer chain, the spatial/temporal dynamic biodistribution as well as metabolism of DPP NP in vivo can be monitored by Pt DMCT imaging to guide the light irradiation parameters for optimized light-activatable synergistic chemotherapy. Guided by Pt DMCT imaging, DPP NP was able to achieve an improved light-activatable antitumor efficacy, with 75% tumors fully cured and low toxicity. The light-activatable DDP NP system exhibits tremendous potential as precise theranostic nanomedicine. STATEMENT OF SIGNIFICANCE: The synergistic efficacy and clinical application of light-responsive polymeric co-delivery systems are severely restricted by uncontrollable/imprecise drug loading, delivery, and release, as well as adverse effects caused by the introduction of additional light-responsive molecules or contrast agents when diagnostic imaging is applied to guide therapy. Herein, we report the design of a light-activatable dual prodrug polymer nanoparticle (DPP NP) for precise synergistic chemotherapy guided by drug-mediated computed tomography imaging without the introduction of any additional diagnostic imaging agents. Notably, the drug loading ratio of Pt(II) and DMC in DPP NP was fixed at an optimal value to achieve maximum synergistic cancer cell killing, which was kept even after cellular uptake, thereby resulting in enhanced synergistic antitumor efficacy both in vitro and in vivo. The light-activatable DDP NP system exhibits tremendous potential as precise theranostic nanomedicine.

Fe3O4@SiO2mesoporous spheres as Fe(ii) donors loaded with artemisinin and a photosensitizer to alleviate tumor hypoxia in PDT for enhanced anticancer therapy

Fe₃O₄@SiO₂as an Fe(ii) donor loaded with artemisinin and photosensitizer to alleviate hypoxia in PDT showed excellent anticancer activity.

Diazido platinum(iv) complexes for photoactivated anticancer chemotherapy

Diazido Pt(iv) complexes with a general formula [Pt(N₃)₂(L)(L′)(OR)(OR′)] are a new generation of anticancer prodrugs designed for use in photoactivated chemotherapy.

Stimuli-Responsive Therapeutic Metallodrugs

The success of platinum-based anticancer agents has motivated the exploration of novel metal-based drugs for several decades, whereas problems such as drug-resistance and systemic toxicity hampered their clinical applications and efficacy. Stimuli-responsiveness of some metal complexes offers a good opportunity for designing site-specific prodrugs to maximize the therapeutic efficacy and minimize the side effect of metallodrugs. This review presents a comprehensive and up-to-date overview on the therapeutic stimuli-responsive metallodrugs that have appeared in the past two decades, where stimuli such as redox, pH, enzyme, light, temperature, and so forth were involved. The compounds are classified into three major categories based on the nature of stimuli, that is, endo-stimuli-responsive metallodrugs, exo-stimuli-responsive metallodrugs, and dual-stimuli-responsive metallodrugs. Representative examples of each type are discussed in terms of structure, response mechanism, and potential medical applications. In the end, future opportunities and challenges in this field are tentatively proposed. With diverse metal complexes being introduced, the foci of this review are pointed to platinum and ruthenium complexes.

Tailoring Platinum(IV) Amphiphiles for Self-Targeting All-in-One Assemblies as Precise Multimodal Theranostic Nanomedicine

Drug, targeting ligand, and imaging agent are the three essential components in a nanoparticle-based drug delivery system. However, tremendous batch-to-batch variation of composition and drug content typically accompany the current approaches of building these components together. Herein, we report the design of photoactivatable platinum(IV) (Pt(IV)) amphiphiles containing one or two hydrophilic lactose targeting ligands per hydrophobic Pt(IV) prodrug for an all-in-one precise nanomedicine. Self-assembly of these Pt(IV) amphiphiles results in either micelle or vesicle formation with a fixed Pt/targeting moiety ratio and a constantly high content of Pt. The micelles and vesicles are capable of hepatoma cell-targeting, fluorescence/Pt-based CT imaging and have shown effective anticancer efficacy under laser irradiation in vitro and in vivo. This photoactivatable, active self-targeting, and multimodal theranostic amphiphile strategy shows great potential in constructing precise nanomedicine.

Design of pH-sensitive methotrexate prodrug-targeted curcumin nanoparticles for efficient dual-drug delivery and combination cancer therapy

Aim

We designed acid-labile methotrexate (MTX) targeting prodrug self-assembling nanoparticles loaded with curcumin (CUR) drug for simultaneous delivery of multi-chemotherapeutic drugs and combination cancer therapy.

Methods

A dual-acting MTX, acting as both an anticancer drug and as a tumor-targeting ligand, was coupled to 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[aldehyde(polyethylene glycol)-2000] via Schiff's base reaction. The synthesized prodrug conjugate (DSPE-PEG-Imine-MTX) could be self-assembled into micellar nanoparticles (MTX-Imine-M) in aqueous solution, which encapsulated CUR into their core by hydrophobic interactions (MTX-Imine-M-CUR).

Results

The prepared MTX-Imine-M-CUR nanoparticles were composed of an inner hydrophobic DSPE/CUR core and an outside hydrophilic bishydroxyl poly (ethyleneglycol) (PEG) shell with a self-targeting MTX prodrug corona. The imine linker between 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[aldehyde(polyethyleneglycol)-2000] and MTX, as a dynamic covalent bond, was strong enough to remain intact in physiological pH, even though it is rapidly cleaved in acidic pH. The MTX-Imine-M-CUR could codeliver MTX and CUR selectively and efficiently into the cancer cells via folate receptor-mediated endocytosis followed by the rapid intracellular release of CUR and the active form of MTX via the acidity of endosomes/lysosomes. Moreover, the MTX-Imine-M-CUR resulted in significantly higher in vitro and in vivo anticancer activity than pH-insensitive DSPE-PEGAmide-MTX assembling nanoparticles loaded with CUR (MTX-Amide-M-CUR), MTX unconjugated DSPE-PEG assembling micellar nanoparticles loaded with CUR (M-CUR), combination of both free drugs, and individual free drugs.

Conclusion

The smart system provided a simple, yet feasible, drug delivery strategy for targeted combination chemotherapy.

Enhancing Photochemical Internalization of DOX through a Porphyrin-based Amphiphilic Block Copolymer

Drug resistance is a primary obstacle that seriously reduces the therapy efficiency of most chemotherapeutic agents. To address this issue, the photochemical internalization (PCI) was employed to help the anticancer drug escape from lysosome and improve their translocation to the nucleus. A pH-sensitive porphyrin-based amphiphilic block copolymer (PEG₁₁₃-b-PCL₅₄-a-porphyrin) was synthesized, which was acted not only as a carrier for the delivery of DOX but also as a photosensitizer for PCI. PEG₁₁₃-b-PCL₅₄-a-porphyrin as a drug carrier exhibited a higher drug loading capacity, entrapment efficiency, and DOX release content. The PCI effect of PEG₁₁₃-b-PCL₅₄-a-porphyrin was studied by confocal laser scanning microscopy, and the results showed that most of DOX could be translocated into the nucleus for DOX-loaded PEG₁₁₃-b-PCL₅₄-a-porphyrin micelles. Moreover, the IC₅₀ of pH-sensitive DOX-loaded PEG₁₁₃-b-PCL₅₄-a-porphyrin micelles was much lower than that of its counterpart without pH-responsiveness, DOX-loaded PEG₁₁₃-b-PCL₅₄-porphyrin micelles. Therefore, this drug delivery system based on pH-sensitive porphyrin-containing block copolymer would act as a potential vehicle for overcoming drug resistance in chemotherapy.

Dually folate/CD44 receptor-targeted self-assembled hyaluronic acid nanoparticles for dual-drug delivery and combination cancer therapy

Nanoparticles (NPs) functionalized with targeting ligands have shown promise, but are still limited by their nonspecific uptake by certain healthy tissues and cells that express low or even comparable levels of receptors. To increase their accumulation at tumor sites while decreasing the unintended toxicity, a possible solution is the involvement of two separate tumor-specific ligands in the localization. In this study, a dual tumor-targeting drug-loaded NP system was self-assembled by the amphiphilic conjugate of methotrexate-hyaluronic acid-octadecylamine (MTX-HA-OCA) with curcumin (CUR) encapsulated within the hydrophobic core (designated as MTX-HA-OCA/CUR NPs). The advantages of this nanosystem are that the anticancer drug MTX can be utilized as a tumor-targeting ligand toward folate receptors due to its structural similarity to folic acid (FA), and HA can serve as another tumor-targeting ligand toward CD44 receptors. The MTX-HA-OCA/CUR NPs are ∼70 nm in diameter and have sustained/controlled drug release behavior. An in vitro cellular uptake and competition inhibition study exhibited that MTX-HA-OCA/CUR NPs could significantly enhance the internalization efficiency in HeLa cells via folate/CD44 receptor-mediated endocytosis as compared to HA-OCA/CUR NPs. More importantly, the in vitro cytotoxicity of MTX-HA-OCA/CUR NPs was significantly enhanced as compared to those of the HA-OCA/CUR NPs, both free drugs, and individual free drug. Furthermore, the real-time in vivo and ex vivo fluorescence imaging of HeLa tumor-bearing mice showed that MTX-HA-OCA/CUR NPs could more efficiently enhance their accumulation and improve the penetration at the tumor site as compared to HA-OCA/CUR NPs. Therefore, these dually folate/CD44 receptor-targeted self-assembled HA NPs for the co-delivery of both anticancer drugs might provide a promising strategy for dual-targeted combination cancer therapy.

A facile way to prepare functionalized dextran nanogels for conjugation of hemoglobin

Nanogels with several special advantages have been widely applied in protein delivery. However, biocompatible and biodegradable nanogels used for hemoglobin (Hb) delivery are far less explored. Herein, we developed a facile method to prepare functionalized dextran nanogels for conjugation of Hb. In situ cross-linked and aldehyde group functionalized nanogels (FNGs) were prepared from dextran-g-succinic anhydride-g-dopamine conjugate (Dex-SA-DA) assembly by simple pH adjustion and oxidization in water. Hb was further conjugated into the swelling FNGs by Schiff base reaction under mild condition. The obtained hemoglobin-loaded nanogels (HbNGs) exhibited high stability, oxygen affinity and good hemo-compatibility, suggesting the potential for oxygen carriers. We expected that the designed functionalized nanogels with high stability and loading capacity could bring a new opportunity for protein delivery.

Mesoporous silica nanoparticles with lactose-mediated targeting effect to deliver platinum(iv) prodrug for liver cancer therapy

A mesoporous silica nanoparticle system with a lactose-mediated targeting effect was demonstrated to deliver a platinum(iv) prodrug for liver cancer therapy.

Pt(iv) prodrug-backboned micelle and DCA loaded nanofibers for enhanced local cancer treatment

An implantable Pt(iv) prodrug-backboned micelle and DCA loaded electrospun nanofiber system was developed for local combination chemotherapy.

Triple Block Nanocarrier Platform for Synergistic Cancer Therapy of Antagonistic Drugs

A unique biodegradable triple block nanocarrier (TBN) is designed and developed for synergistic combination therapy of antagonistic drugs for cancer treatment. The TBN was built with hydrophilic polyethylene glycol (PEG) outer shell; a middle hydrophobic and biodegradable polycaprolactone (PCL) block for encapsulating anthracycline anticancer drug like doxorubicin (DOX), and an inner carboxylic-functionalized polycaprolactone (CPCL) core for cisplatin (CP) drug conjugation. TBN-cisplatin drug conjugate self-assembled as stable nanoparticles in saline (also in PBS) wherein the hydrophobic PCL block functions as a shield for Pt-drug stability against GSH detoxification. Enzymatic-biodegradation of TBN exclusively occurred at the intracellular environment to deliver both cisplatin (CP) and doxorubicin (DOX) simultaneously to the nucleus. As a result, the TBN-cisplatin conjugate and its DOX-loaded nanoparticles accomplished 100% cell growth inhibition in GSH overexpressed breast cancer cells. Combination therapy revealed that free drugs were antagonistic to each other, whereas the dual drug-loaded TBN exhibited excellent synergistic cell killing at much lower drug concentrations in breast cancer cells. Confocal microscopic analysis confirmed the localization of drugs in the cytoplasm and at peri-nuclear site. Flow cytometry analysis revealed that the drugs were taken up 4-fold better while delivering them from TBN platform compared to free form. The TBNs approach is a perfect platform to overcome the GSH detoxification in Pt-drugs and enable the codelivery of antagonistic drugs like cisplatin and DOX from single polymer dose to accomplish synergistic killing in breast cancer cells.

Simultaneously Photo-Cleavable and Activatable Prodrug-Backboned Block Copolymer Micelles for Precise Anticancer Drug Delivery

A simultaneously photo-cleavable and activatable prodrug-backboned block copolymer (BCP) micelle strategy is demonstrated. Without light treatment, the micelles stay silent and inactivated, being biocompatible to normal tissues. Concurrent chain cleavage of BCP micelles and the activation of Pt(IV) prodrug could be temporally and spatially triggered by UV or even visible light for precise anticancer drug delivery.