Polymeric micelles encapsulating pH-responsive doxorubicin prodrug and glutathione-activated zinc(II) phthalocyanine for combined chemotherapy and photodynamic therapy

Polymeric Nanosystems: A Breakthrough Approach to Treating Inflammation and Inflammation Related Diseases

Inflammation processes can cause mild to severe damage in the human body and can lead to a large number of inflammation-related diseases (IRD) such as cancer, neural, vascular, and pulmonary diseases. Limitations of anti-inflammatory drugs (AID) application are reflected in high therapeutic doses, toxicity, low bioavailability and solubility, side effects, etc. Polymeric nanosystems (PS) have been recognized as a safe and effective technology that is able to overcome these limitations by AID encapsulation and is able to answer to the specific demands of the IRD treatment. PS are attracting great attention due to their versatility, biocompatibility, low toxicity, fine-tuned properties, functionality, and ability for precise delivery of anti-inflammatory drugs to the targeted sites in the human body. This article offers an overview of three classes of polymeric nanosystems: a) dendrimers, b) polymeric micelles and polymeric nanoparticles, and c) polymeric filomicelles, as well as their properties, preparation, and application in IRD treatment. In the future, the number of PS formulations in clinical practice will certainly increase.

pH-sensitive phthalocyanine-loaded polymeric nanoparticles as a novel treatment strategy for breast cancer

Novel pH-sensitive polymeric photosensitizer carriers from the phthalocyanine (Pc) group were investigated as potential photodynamic therapy drugs for the treatment of breast cancer. Their high antiproliferative activity was confirmed by photocytotoxicity studies, which indicated their high efficacy and specificity toward the SK-BR-3 cell line. Importantly, the Pcs encapsulated in the polymeric nanoparticle (NP) carrier exhibited a much better penetration into the acidic environment of tumor cells than their free form. The investigated Pc4-NPs and TT1-NPs exhibited a high selectivity to healthy fibroblasts as well as non-toxicity without irradiation. This paper describes the detailed mechanism of action of the evaluated compounds by measuring reactive oxygen species (ROS), including singlet oxygen; imaging cellular localization; and analyzing key signaling pathway proteins. An additional advantage of the evaluated compounds is their ability to inhibit the Akt protein expression, including its phosphorylation, which the Western blot test confirmed. This is particularly important because breast cancers often overexpress the HER-2 receptor-related signaling proteins. Moreover, an analysis of proteins such as GLUT-1, HO-1, phospho-p42/44, and BID revealed the significant involvement of ROS in disrupting cellular homeostasis, thereby leading to the induction of oxidative stress and resulting in apoptotic cell death.

Improved Control of Triple-Negative Breast Cancer Tumor and Metastasis with a pH-Sensitive Hyaluronic Acid Nanocarrier for Doxorubicin Delivery

Polymer based nanoformulations offer substantial prospects for efficacious chemotherapy delivery. Here, we developed a pH-responsive polymeric nanoparticle based on acidosis-triggered breakdown of boronic ester linkers. A biocompatible hyaluronic acid (HA) matrix served as a substrate for carrying a doxorubicin (DOX) prodrug which also possesses natural affinity for CD44+ cells. DOX was functionalized with a boronic acid group, which was covalently linked with the HA polymer, resulting in a stable chemical linker at neutral pH. Under acidic conditions, the boronic ester linker is degraded, dissociating DOX. Compared to free DOX, the DOX HA NPs exhibited preferential accumulation in 4T1 cells. In a BALB/c mouse model, DOX HA NPs improved antitumor activity, dramatically improved control of lung metastases, and ultimately led to enhanced survival. The pH-sensitive HA nanocarriers provide a promising approach to enhance therapeutic outcomes and reduce toxicity in chemotherapy.

Effect and underlying mechanism of a photochemotherapy dual-function nanodrug delivery system for head and neck squamous cell carcinoma

BACKGROUND

The novel nanomaterials PNA-TN (PN) and PNA-TN-Dox (PND) have been shown to have strong inhibitory effects on breast cancer; however, it is unclear whether PN and PND have anti-head and neck squamous cell carcinoma (HNSCC) activity, and their potential mechanisms of activity are unknown. So, our study aims to explore the therapeutic effects of PN and PND on HNSCC and their possible mechanisms.

METHODS

We used a series of phenotypic research to evaluate the effects of PN + Laser (L) and PND + L on the biological function of HNSCC cells in vitro and in vivo. We subsequently used mechanism research to examine changes in mRNA and protein expression related to apoptosis, epithelial‒mesenchymal transition (EMT), and the JNK signalling pathway.

RESULTS

Our study revealed that PN and PND have strong inhibitory effects on HNSCC cells both in vitro and in vivo. In vitro, PN and PND significantly inhibited the proliferation, migration, invasion and EMT ability of HNSCC cells and promoted apoptosis; the inhibitory effect in the PND + L group was significantly greater than that in the PN + L group. In vivo, both treatments led to significant reductions in tumour volume and weight. Notably, the tumour volume and weight in the PND + L group were significantly lower than those in the PN + L group. Mechanism research confirmed that PN + L activated the expression of apoptosis-related proteins and inhibited the expression of EMT-related proteins via the JNK pathway. Furthermore, the anti-HNSCC effect of PN + L was blocked after the use of a JNK pathway inhibitor.

CONCLUSION

Treatment with PN + L or PND + L significantly inhibited the malignant progress of HNSCC cells, and the therapeutic effect of PND + L was significantly stronger than that of PN + L. The JNK signalling pathway is a key mechanism by which PN exerts its anti-HNSCC activity.

ROS-responsive glycol chitosan-linked prodrug nanoparticle as a nanoplatform for tumor chemo-photodynamic therapy

Herein, we designed and synthesized novel reactive oxygen species (ROS)-responsive glycol chitosan-doxorubicin (DOX) prodrug via a ROS-cleavable thioketal (TK) linker. The obtained GC-TK-DOX formed self-assembled nanoparticles of 312 nm in aqueous media. Photosensitizers zinc phthalocyanine (ZnPc)-loaded GC-TK-DOX (GC-TK-DOX/ZnPc) nanoparticles were fabricated by using a dialysis approach. The GC-TK-DOX and GC-TK-DOX/ZnPc nanoparticles were nearly spherical by transmission electron microscopy (TEM) observation. Under 660-nm laser irradiation, GC-TK-DOX/ZnPc could generate singlet oxygen. Further, GC-TK-DOX/ZnPc nanoparticles exhibited ROS-sensitive release of DOX and ZnPc in vitro. GC-TK-DOX/ZnPc with laser irradiation showed more drug uptake and higher cytotoxic effects than GC-TK-DOX/ZnPc without irradiation, free DOX and GC-TK-DOX in HeLa tumor cells. Overall, these findings suggested that GC-TK-DOX/ZnPc could be a promising nanoarchitecture for synergetic chemo-photodynamic therapy against tumors.

Carboxymethyl chitosan-based nanoparticles of acid response for the synergistic anti-tumor effect of PDT and chemotherapy

The combination of multiple anti-tumor methods has shown significant application potential in overcoming the limitations of monotherapy. Photodynamic therapy (PDT) and chemotherapy combination is a promising strategy for reducing drug resistance and side effects. Here, inspired by the acidic environment of tumors, carboxymethyl chitosan-based pH-responsive nanovesicles were developed to co-deliver the chemotherapeutic drug doxorubicin (DOX) and photosensitizer 5-aminolevulinic acid (5-ALA). The in vitro drug release studies revealed that drugs could be responsively released when nanoparticles were triggered by the acidic environment. The controlled-release behavior improved drug retention and reduced the administration time. Our nanoparticles could significantly enhance the killing effect of drugs on tumor cells and increase intracellular levels of reactive oxygen species (ROS) compared to monotherapy, effectively achieving the effects of combined chemotherapy and PDT. The loaded DOX could kill tumor cells and the loaded 5-ALA could enhance the content of protoporphyrin IX (PpIX), resulting in excess ROS production to improve the effects of PDT. In summary, our nanoparticles could co-deliver the drugs and exert synergistical anti-tumor of PDT and chemotherapy by suppressing tumor cell proliferation and facilitating cell apoptosis.

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Recent progress in stimuli-responsive polymeric micelles for targeted delivery of functional nanoparticles

Stimuli-responsive polymeric micelles have emerged as a revolutionary approach for enhancing the in vivo stability, biocompatibility, and targeted delivery of functional nanoparticles (FNPs) in biomedicine. This article comprehensively reviews the preparation methods of these polymer micelles, detailing the innovative strategies employed to introduce stimulus responsiveness and surface modifications essential for precise targeting. We delve into the breakthroughs in utilizing these micelles to selectively deliver various FNPs including magnetic nanoparticles, upconversion nanoparticles, gold nanoparticles, and quantum dots, highlighting their transformative impact in the biomedical realm. Concluding, we present an insight into the current research landscape, addressing the challenges at hand, and envisioning the future trajectory in this burgeoning domain. Join us as we navigate the exciting confluence of polymer science and nanotechnology in reshaping biomedical solutions.

Photodynamic therapy for cancer: mechanisms, photosensitizers, nanocarriers, and clinical studies

Photodynamic therapy (PDT) is a temporally and spatially precisely controllable, noninvasive, and potentially highly efficient method of phototherapy. The three components of PDT primarily include photosensitizers, oxygen, and light. PDT employs specific wavelengths of light to active photosensitizers at the tumor site, generating reactive oxygen species that are fatal to tumor cells. Nevertheless, traditional photosensitizers have disadvantages such as poor water solubility, severe oxygen-dependency, and low targetability, and the light is difficult to penetrate the deep tumor tissue, which remains the toughest task in the application of PDT in the clinic. Here, we systematically summarize the development and the molecular mechanisms of photosensitizers, and the challenges of PDT in tumor management, highlighting the advantages of nanocarriers-based PDT against cancer. The development of third generation photosensitizers has opened up new horizons in PDT, and the cooperation between nanocarriers and PDT has attained satisfactory achievements. Finally, the clinical studies of PDT are discussed. Overall, we present an overview and our perspective of PDT in the field of tumor management, and we believe this work will provide a new insight into tumor-based PDT.

Biomedical Application of Porphyrin-Based Amphiphiles and Their Self-Assembled Nanomaterials

Porphyrins have been vastly explored and applied in many cutting-edge fields with plenty of encouraging achievements because of their excellent properties. As important derivatives of porphyrins, porphyrin-based amphiphiles (PBAs) not only maintain the advanced properties of porphyrins (catalysis, imaging, and energy transfer) but also possess self-assembly and encapsulation capability in aqueous solution. Accordingly, PBAs and their self-assembles have had important roles in diagnosing and treating tumors and inflammation lesions in vivo, but not limited to these. In this article, we introduce the research progress of PBAs, including their constitution, structure design strategies, and performances in tumor and inflammation lesion diagnosis and treatments. On that basis, the defects of synthesized PBAs during their application and the possible effective strategies to overcome the limitations are also proposed. Finally, perspectives on PBAs exploration are updated based on our knowledge. We hope this review will bring researchers from various domains insights about PBAs.

Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis

Pharmaceutical analysis refers to an area of analytical chemistry that deals with active compounds either by themselves (drug substance) or when formulated with excipients (drug product). In a less simplistic way, it can be defined as a complex science involving various disciplines, e.g., drug development, pharmacokinetics, drug metabolism, tissue distribution studies, and environmental contamination analyses. As such, the pharmaceutical analysis covers drug development to its impact on health and the environment. Moreover, due to the need for safe and effective medications, the pharmaceutical industry is one of the most heavily regulated sectors of the global economy. For this reason, powerful analytical instrumentation and efficient methods are required. In the last decades, mass spectrometry has been increasingly used in pharmaceutical analysis both for research aims and routine quality controls. Among different instrumental setups, ultra-high-resolution mass spectrometry with Fourier transform instruments, i.e., Fourier transform ion cyclotron resonance (FTICR) and Orbitrap, gives access to valuable molecular information for pharmaceutical analysis. In fact, thanks to their high resolving power, mass accuracy, and dynamic range, reliable molecular formula assignments or trace analysis in complex mixtures can be obtained. This review summarizes the principles of the two main types of Fourier transform mass spectrometers, and it highlights applications, developments, and future perspectives in pharmaceutical analysis.

Research progress of natural silk fibroin and the appplication for drug delivery in chemotherapies

Silk fibroin has been widely used in biological fields due to its biocompatibility, mechanical properties, biodegradability, and safety. Recently, silk fibroin as a drug carrier was developed rapidly and achieved remarkable progress in cancer treatment. The silk fibroin-based delivery system could effectively kill tumor cells without significant side effects and drug resistance. However, few studies have been reported on silk fibroin delivery systems for antitumor therapy. The advancement of silk fibroin-based drug delivery systems research and its applications in cancer therapy are highlighted in this study. The properties, applications, private opinions, and future prospects of silk fibroin carriers are discussed to understand better the development of anti-cancer drug delivery systems, which may also contribute to advancing silk fibroin innovation.

Chlorophenyl thiophene silicon phthalocyanine: Synthesis, two-photon bioimaging-guided lysosome target, and in vitro photodynamic efficacy

The development of efficient photosensitizers with high singlet oxygen quantum yield, strong fluorescent emission, excellent photostability, and specific organelle targeting is in great demand for the enhancement of PDT treatment efficiency. This study designed and synthesized a new two-photon photosensitizer chlorophenyl thiophene axially substituted silicon (IV) phthalocyanine (CBT-SiPc). CBT-SiPc showed specific targeting of lysosomes in living cells and good biocompatibility. Furthermore, high ¹O₂ generation efficiency and high PDT efficiency in MCF-7 breast cancers under irradiation were also demonstrated. The novel CBT-SiPc showed great potential in the application of lysosome-targeted and two-photon bioimaging-guided photodynamic cancer therapy.

NIR/MRI-Guided Oxygen-Independent Carrier-Free Anti-Tumor Nano-Theranostics

Imaging-guided photothermal therapy (PTT)/photodynamic therapy (PDT) for cancer treatment are beneficial for precise localization of the malignant lesions and combination of multiple cell killing mechanisms in eradicating stubborn thermal-resistant cancer cells. However, overcoming the adverse impact of tumor hypoxia on PDT efficacy remains a challenge. Here, carrier-free nano-theranostic agents are developed (AIBME@IR780-APM NPs) for magnetic resonance imaging (MRI)-guided synergistic PTT/thermodynamic therapy (TDT). Two IR780 derivatives are synthesized as the subject of nanomedicine to confer the advantages for the nanomedicine, which are by feat of amphiphilic IR780-PEG to enhance the sterical stability and reduce the risk from reticuloendothelial system uptake, and IR780-ATU to chelate Mn²⁺ for T₁ -weighted MRI. Dimethyl 2,2'-azobis(2-methylpropionate) (AIBME), acting as thermally decomposable radical initiators, are further introduced into nanosystems with the purpose of generating highly cytotoxic alkyl radicals upon PTT launched by IR780 under 808 nm laser irradiation. Therefore, the sequentially generated heat and alkyl radicals synergistically induce cell death via synergistic PTT/TDT, ignoring tumor hypoxia. Moreover, these carrier-free nano-theranostic agents present satisfactory biocompatibility, which could be employed as a powerful weapon to hit hypoxic tumors via MRI-guided oxygen-independent PTT and photonic TDT.

Evaluation and antitumor mechanism of functionalized chitosan-based polymeric micelles for oral delivery of paclitaxel

D-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS)-modified carboxymethyl chitosan-rhein (TCR) polymeric micelles (PMs) self-assembled by TCR conjugate were constructed for oral delivery of paclitaxel (PTX). PTX-loaded TCR PMs with a drug loading capacity of 47.52 ± 1.65 % significantly improved the intestinal absorption and oral bioavailability of PTX. TCR PMs loaded with PTX displayed time- and concentration-dependent cytotoxicity in Caco-2, MCF-7 and Taxol-resistant MCF-7 (MCF-7/Taxol) cells. In MCF-7/Taxol cells, PTX-loaded TCR PMs promoted apoptosis and changed cell cycle, and TCR conjugate exhibited a P-gp inhibition ability and caused ATP depletion. Moreover, confocal imaging of intestinal sections, Caco-2 cell uptake assay and in vivo bioimaging using environmental response fluorescence probe suggested that TCR PMs loaded with drugs can be absorbed as a whole through the intestinal epithelium after oral administration, enter systemic circulation, and then get to the tumor site. Remarkably, PTX-loaded TCR PMs displayed a significant antitumor effect in H22 tumor xenograft mice and the MCF-7 or MCF-7/Taxol xenograft zebrafish model, which was related to the inhibitory function of TCR conjugate for P-gp activity and P-gp and MDR1 expression. Functionalized TCR PMs are expected to improve the oral therapeutic efficacy of poorly water-soluble antitumor drugs and treat drug-resistant tumors.

The in vivo fate of polymeric micelles

This review aims to provide a systemic analysis of the in vivo, as well as subcellular, fate of polymeric micelles (PMs), starting from the entry of PMs into the body. Few PMs are able to cross the biological barriers intact and reach the circulation. In the blood, PMs demonstrate fairly good stability mainly owing to formation of protein corona despite controversial results reported by different groups. Although the exterior hydrophilic shells render PMs "long-circulating", the biodistribution of PMs into the mononuclear phagocyte systems (MPS) is dominant as compared with non-MPS organs and tissues. Evidence emerges to support that the copolymer poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) is first broken down into pieces of PEG and PLA and then remnants to be eliminated from the body finally. At the cellular level, PMs tend to be internalized via endocytosis due to their particulate nature and disassembled and degraded within the cell. Recent findings on the effect of particle size, surface characteristics and shape are also reviewed. It is envisaged that unraveling the in vivo and subcellular fate sheds light on the performing mechanisms and gears up the clinical translation of PMs.

Poly (Thioether-Polyesters) Micelles Encapsulation Induces ROS-Triggered Targeted Release of Tangeretin

Tangeretin (Tan) possesses great anti-oxidation and anti-inflammation bioactivities; however, it is accompanied by poor water solubility, which leads to inefficient cellular internalization. To address this issue, a reactive oxygen species (ROS)-triggered poly (thioether-polyesters) micelle (PDHP, PEG-DTT) was designed and prepared via self-assembly, which consisted of poly (thioether-polyesters) as the hydrophilic shell, and the drug Tan as the hydrophobic inner core. The micelles (Tan@ PDHP), with a 63.15% loading efficiency of Tan, showed negligible cytotoxicity, high stability in phosphate-buffered saline buffer (pH  =  7.4), and continuous release of Tan with the stimulation of H2O2. In addition, this Tan loading micelle was more efficient in responding to the formation of ROS in the lipopolysaccharide-stimulated RAW264.7 cells compared to that of the free Tan. In short, the strategy of encapsulating the low solubility Tan in ROS-triggered poly (thioether-polyesters) micelles provides an effective assay of enhancing Tan's antioxidative activity.

Fabrication of pH/Redox Dual-Responsive Mixed Polyprodrug Micelles for Improving Cancer Chemotherapy

In this work, we prepared pH/redox dual-responsive mixed polyprodrug micelles (MPPMs), which were co-assembled from two polyprodrugs, namely, poly(ethylene glycol) methyl ether-b-poly (β-amino esters) conjugated with doxorubicin (DOX) via redox-sensitive disulfide bonds (mPEG-b-PAE-ss-DOX) and poly(ethylene glycol) methyl ether-b-poly (β-amino esters) conjugated with DOX via pH-sensitive cis-aconityl bonds (mPEG-b-PAE-cis-DOX) for effective anticancer drug delivery with enhanced therapeutic efficacy. The particle size of MPPMs was about 125 nm with low polydispersity index, indicating the reasonable size and uniform dispersion. The particle size, zeta-potential, and critical micelle concentration (CMC) of MPPMs at different mass ratios of the two kinds of polyprodrugs were dependent on pH value and glutathione (GSH) level, suggesting the pH and redox responsiveness. The drug release profiles in vitro of MPPMs at different conditions were further studied, showing the pH—and redox-triggered drug release mechanism. Confocal microscopy study demonstrated that MPPMs can effectively deliver doxorubicin molecules into MDA-MB-231 cells. Cytotoxicity assay in vitro proved that MPPMs possessed high toxic effect against tumor cells including A549 and MDA-MB-231. The results of in vivo experiments demonstrated that MPPMs were able to effectively inhibit the tumor growth with reduced side effect, leading to enhanced survival rate of tumor-bearing mice. Taken together, these findings revealed that this pH/redox dual-responsive MPPMs could be a potential nanomedicine for cancer chemotherapy. Furthermore, it could be a straightforward way to fabricate the multifunctional system basing on single stimuli-responsive polyprodrugs.

Synergic Antitumor Effect of Photodynamic Therapy and Chemotherapy Mediated by Nano Drug Delivery Systems

This review provides a summary of recent progress in the development of different nano-platforms for the efficient synergistic effect between photodynamic therapy and chemotherapy. In particular, this review focuses on various methods in which photosensitizers and chemotherapeutic agents are co-delivered to the targeted tumor site. In many cases, the photosensitizers act as drug carriers, but this review, also covers different types of appropriate nanocarriers that aid in the delivery of photosensitizers to the tumor site. These nanocarriers include transition metal, silica and graphene-based materials, liposomes, dendrimers, polymers, metal–organic frameworks, nano emulsions, and biologically derived nanocarriers. Many studies have demonstrated various benefits from using these nanocarriers including enhanced water solubility, stability, longer circulation times, and higher accumulation of therapeutic agents/photosensitizers at tumor sites. This review also describes novel approaches from different research groups that utilize various targeting strategies to increase treatment efficacy through simultaneous photodynamic therapy and chemotherapy.

Construction of disulfide containing redox-responsive polymeric nanomedicine

Disulfide bonds (S-S) are widely found in chemistry, biology, and materials science. Polymer nanomaterials containing disulfide bonds with a variety of excellent properties have great potential as drug and gene delivery carriers. The disulfide bond can exist stably in extracellular environment, but upon entering cancer cells, it will undergo a sulfhydryl-disulfide bond exchange reaction with glutathione (GSH) in the cytoplasm, causing the disulfide bond cleavage. Therefore, polymeric nanomaterials containing disulfide bonds are promising in cancer treatment due to the elevated GSH concentration inside cancer cells. This review highlights various synthetic approaches to prepare disulfide containing redox-responsive polymeric nanomedicine, including synthesis of disulfide bonds containing polymers, construction of polymeric nanoparticle with shell or core crosslinked disulfide bonds, preparation of polymer-drug conjugates via disulfide linkers, and disulfide linked responsive payloads.

Glutathione-degradable polydopamine nanoparticles as a versatile platform for fabrication of advanced photosensitisers for anticancer therapy

A series of glutathione (GSH)-responsive polydopamine (PDA) nanoparticles (NPs) were prepared using a disulfide-linked dopamine dimer as starting material, of which the size could be tuned systematically by adjusting the amount of ammonia solution used. Molecules of a phthalocyanine (Pc)-based photosensitiser and an epidermal growth factor receptor (EGFR)-targeting peptide were then sequentially immobilised on the surface of the NPs through coupling with the surface functionalities of PDA. The immobilised Pc molecules in the resulting nanosystem were photodynamically inactive due to the strong self-quenching effect and the quenching by the PDA core. Upon exposure to GSH in phosphate-buffered saline or EGFR-positive cancer cells, namely A549 and A431 cells, the NPs were disassembled through cleavage of the disulfide linkages to release the Pc molecules, thereby restoring their fluorescence emission and singlet oxygen generation. The NPs with the smallest size (ca. 200 nm in diameter) exhibited the highest cellular uptake and high photocytotoxicity with IC₅₀ values as low as 0.05 μM based on Pc. These NPs could also accumulate and be activated in the tumour of A431 tumour-bearing nude mice, lighting up the tumour with fluorescence over a period of 72 h and completely eradicating the tumour through laser irradiation for 10 min (675 nm, 20 J cm^-2). The results suggest that these biodegradable and versatile PDA-based NPs can serve as a promising nanoplatform for fabrication of advanced photosensitisers for targeted photodynamic therapy.

Multi-functional polymeric micelles for chemotherapy-based combined cancer therapy

Currently, the therapeutic performance of traditional mono-chemotherapy on cancers remains unsatisfactory because of the tumor heterogeneity and multidrug resistance. In light of intricate tumor structures and distinct tumor microenvironments (TMEs), combinational therapeutic strategies with multiple anticancer drugs from different mechanisms can synergistically optimize the outcomes and concomitantly minimize the adverse effects during the therapy process. Extensive research on polymeric micelles (PMs) for biomedical applications has revealed the growing importance of nanomedicines for cancer therapy in the recent decade. Starting from traditional simple delivery systems, PMs have been extended to multi-faceted therapeutic strategies. Here we review and summarize the most recent advances in combinational therapy based on multifunctional PMs including a combination of multiple anticancer drugs, chemo-gene therapy, chemo-phototherapy and chemo-immunotherapy. The design approaches, action mechanisms and therapeutic applications of these nanodrugs are summarized. In addition, we highlight the opportunities and potential challenges associated with this promising field, which will provide new guidelines for advanced combinational cancer chemotherapy.

Nanoparticles for Triple Drug Release for Combined Chemo- and Photodynamic Therapy

A pH-responsive drug delivery system (DDS) based on mesoporous silica nanoparticles (MSNs) has been prepared for the delivery of three anticancer drugs with different modes of action. The novelty of this system is its ability to combine synergistic chemotherapy and photodynamic therapy. A photoactive conjugate of a phthalocyanine (Pc) and a topoisomerase I inhibitor (topo-I), namely camptothecin (CPT), linked by a poly(ethylene glycol) (PEG) chain has been synthesized and then loaded into the mesopores of MSNs. Doxorubicin (DOX), which is a topoisomerase II inhibitor (topo-II), has also been covalently anchored to the outer surface of the MSNs through a dihydrazide PEG linker. In the acidic environment of tumor cells, selective release of the three drugs takes place. In vitro studies have demonstrated the endocytosis of the system into HeLa and HepG2 cells, and the subsequent release of the three drugs into the cytoplasm and nucleus. Furthermore, the cytotoxic effect of DOX, CPT and Pc has been assessed in vitro before and upon light irradiation.

Reactive oxygen species-responsive polydopamine nanoparticles for targeted and synergistic chemo and photodynamic anticancer therapy

A thioketal-linked dimer of 3,4-dihydroxy-L-phenylalanine was prepared which underwent self-polymerisation in the presence of doxorubicin (Dox) in an ethanol/water (1 : 4, v/v) mixture with ammonia. The resulting Dox-encapsulated polydopamine (PDA) nanoparticles were further conjugated with molecules of a zinc(II) phthalocyanine (Pc)-based photosensitiser and a peptide containing the heptapeptide QRHKPRE sequence (labelled as QRH) that can target the epidermal growth factor receptor (EGFR) overexpressed in cancer cells. Upon internalisation into these cells through receptor-mediated endocytosis, these nanoparticles labelled as PDA-Dox-Pc-QRH were disassembled gradually via cleavage of the thioketal linkages by the intrinsic intracellular reactive oxygen species (ROS). The stacked Pc molecules were then disaggregated, resulting in activation of their photosensitising property upon irradiation. The ROS generated by the activated Pc promoted further degradation of the nanoparticles and release of Dox, thereby enhancing cell death by synergistic chemo and photodynamic therapy. Systemic injection of PDA-Dox-Pc-QRH into EGFR-overexpressed tumour-bearing nude mice led to targeted delivery to the tumour, and subsequent light irradiation caused complete tumour ablation without inducing notable toxicity.

Recent Progress in Phthalocyanine-Polymeric Nanoparticle Delivery Systems for Cancer Photodynamic Therapy

This perspective article summarizes the last decade’s developments in the field of phthalocyanine (Pc)-polymeric nanoparticle (NP) delivery systems for cancer photodynamic therapy (PDT), including studies with at least in vitro data. Moreover, special attention will be paid to the various strategies for enhancing the behavior of Pc-polymeric NPs in PDT, underlining the great potential of this class of nanomaterials as advanced Pcs’ nanocarriers for cancer PDT. This review shows that there is still a lot of research to be done, opening the door to new and interesting nanodelivery systems.

Nanoscale Metal-Organic Framework Confines Zinc-Phthalocyanine Photosensitizers for Enhanced Photodynamic Therapy

The performance of photodynamic therapy (PDT) depends on the solubility, pharmacokinetic behaviors, and photophysical properties of photosensitizers (PSs). However, highly conjugated PSs with strong reactive oxygen species (ROS) generation efficiency tend to have poor solubility and aggregate in aqueous environments, leading to suboptimal PDT performance. Here, we report a new strategy to load highly conjugated but poorly soluble zinc-phthalocyanine (ZnP) PSs in the pores of a Hf₁₂-QC (QC = 2″,3′-dinitro-[1,1’:4′,1”;4″,1’”-quaterphenyl]-4,4’”-dicarboxylate) nanoscale metal–organic framework to afford ZnP@Hf-QC with spatially confined ZnP PSs. ZnP@Hf-QC avoids aggregation-induced quenching of ZnP excited states to significantly enhance ROS generation upon light irradiation. With higher cellular uptake, enhanced ROS generation, and better biocompatibility, ZnP@Hf-QC mediated PDT exhibited an IC₅₀ of 0.14 μM and achieved exceptional antitumor efficacy with >99% tumor growth inhibition and 80% cure rates on two murine colon cancer models.

Star polyester-based folate acid-targeting nanoparticles for doxorubicin and curcumin co-delivery to combat multidrug-resistant breast cancer

Chemotherapeutic treatments are indispensable in the treatment of breast cancer. However, the emergence of multidrug-resistance, strong cell toxicity, and poor targeting selection has inhibited their clinical application. In this study, two synergistic drugs, doxorubicin (DOX) and curcumin (CUR), were co-administered to overcome multidrug resistance (MDR). Based on the characteristics of the tumor microenvironment, we developed folic acid-modified nanoparticles ((DOX + CUR)-FA-NPs) based on a star-shaped polyester (FA-TRI-CL) to enhance the tumor targeting selectivity and drug loading (DL) capacity. The (DOX + CUR)-FA-NPs displayed a characteristic spheroid morphology with an ideal diameter (186.52 nm), polydispersity index (0.024), zeta potential (-18.87 mV), and good entrapment efficiency (97.64%/78.13%, DOX/CUR) and DL (20.27%/11.29%, DOX/CUR) values. In vitro pharmacokinetic and pharmacodynamic experiments demonstrated that the (DOX + CUR)-FA-NPs were gradually released, and they displayed the highest cell apoptosis and cellular uptake in MCF-7/ADR cells. Additionally, in vivo results illustrated that (DOX + CUR)-FA-NPs not only displayed significant tumor targeting and anticancer efficacy, but also induced less pathological damage to the normal tissue. In summary, co-administered DOX and CUR appeared to reverse MDR, and this targeted combinational nanoscale delivery system could thus be a promising carrier for tumor therapies in the future.

New contrast agents for photoacoustic imaging and theranostics: Recent 5-year overview on phthalocyanine/naphthalocyanine-based nanoparticles

The phthalocyanine (Pc) and naphthalocyanine (Nc) nanoagents have drawn much attention as contrast agents for photoacoustic (PA) imaging due to their large extinction coefficients and long absorption wavelengths in the near-infrared region. Many investigations have been conducted to enhance Pc/Ncs' photophysical properties and address their poor solubility in an aqueous solution. Many diverse strategies have been adopted, including centric metal chelation, structure modification, and peripheral substitution. This review highlights recent advances on Pc/Nc-based PA agents and their extended use for multiplexed biomedical imaging, multimodal diagnostic imaging, and image-guided phototherapy.

Imaging and detection of cell apoptosis byIn vitrophotodynamic therapy applications of zinc (II) phthalocyanine on human melanoma cancer

This study aims to investigate the photodynamic therapy (PDT) effects on MeWo (human melanoma cells) and HaCaT (normal human keratinocyte cells) by light stimulation of different concentrations of Zinc (II)-tetra-tert-butyl-phthalocyaninato (ZnPc). MTT viability assay data indicated that a 25 μM concentration of ZnPc is cytotoxic to the melanoma cancer cells while this concentration of ZnPc is not cytotoxic for the HaCaT cell line. Moreover, the results showed that photoactivated ZnPc at 12.5 μM concentration reduced the cell viability of the MeWo cell line to about 50 %. At this photosensitizing concentration, the efficacy of light doses of 20, 30, 40, and 50 J/cm² was evaluated against MeWo and HaCaT cells. ZnPc at a concentration of 12.5 μM activated with a light dose of 50 J/cm² was the most efficient for the killing of MeWo cells. In conclusion, the 12.5 μM of ZnPc with the treatment light dose of 50 J/cm² from a RED light source was adequate to destroy MeWo cells by the ROS-induced apoptosis mechanism. It also exhibited low killing effects on healthy HaCaT cells. These findings are supported by the results of apoptosis with the Annexin V & Dead Cell Kit and fluorescence imaging.

Encapsulating an acid-activatable phthalocyanine-doxorubicin conjugate and the hypoxia-sensitive tirapazamine in polymeric micelles for multimodal cancer therapy

A zinc(ii) phthalocyanine (ZnPc) was conjugated to doxorubicin (Dox) via an acid-labile hydrazone linker. The resulting ZnPc-Dox conjugate was then encapsulated into polymeric micelles formed through self-assembly of a block copolymer of poly(ethylene glycol) and poly(d,l-lactide) both in the absence and presence of the hypoxia-activated prodrug tirapazamine (TPZ) to give ZnPc-Dox@micelles and ZnPc-Dox/TPZ@micelles respectively. These polymeric micelles exhibited an excellent stability in aqueous media, but underwent disassembly in an acidic environment. Upon internalisation into HT29 human colorectal carcinoma cells, fluorescence due to ZnPc and Dox could be observed in the cytoplasm and nucleus respectively for both nanosystems. This observation suggested the disassembly of the polymeric micelles and the cleavage of the hydrazone linker in ZnPc-Dox in the acidic intracellular compartments. These micelles were slightly cytotoxic against HT29 cells in the dark due to the chemotherapeutic effect of Dox and/or TPZ. Upon light irradiation, ZnPc-Dox@micelles showed higher cytotoxicity. The IC50 value under a normoxic condition (0.35 μM based on ZnPc-Dox) was significantly lower than that under hypoxia (>1 μM). With an additional therapeutic component, ZnPc-Dox/TPZ@micelles exhibited higher photocytotoxicity with IC50 values of 0.20 μM and 0.78 μM under normoxia and hypoxia respectively. It is believed that the photodynamic action of this nanosystem consumed the intracellular oxygen and hence triggered the hypoxia-mediated chemotherapeutic action of TPZ. The multimodal antitumor effects of these polymeric micelles were also validated on HT29 tumour-bearing nude mice.

Curcumin-Loaded Hybrid Nanoparticles: Microchannel-Based Preparation and Antitumor Activity in a Mouse Model

Purpose

To develop microchannel-based preparation of curcumin (Cur)-loaded hybrid nanoparticles using enzyme-targeted peptides and star-shaped polycyclic lipids as carriers, and to accomplish a desirable targeted drug delivery via these nanoparticles, which could improve the bioavailability and antitumor effects of Cur.

Methods

The amphiphilic tri-chaintricarballylic acid-poly (ε-caprolactone)-methoxypolyethylene glycol (Tri-CL-mPEG) and the enzyme-targeted tetra-chain pentaerythritol-poly (ε-caprolactone)-polypeptide (PET-CL-P) were synthesized. The Cur-loaded enzyme-targeted hybrid nano-delivery systems (Cur-P-NPs) were prepared by using the microfluidic continuous granulation technology. The physicochemical properties, release behavior in vitro, and stability of these Cur-P-NPs were investigated. Their cytotoxicity, cellular uptake, anti-proliferative efficacy in vitro, biodistribution, and antitumor effects in vivo were also studied.

Results

The particle size of the prepared Cur-P-NPs was 146.1 ± 1.940 nm, polydispersity index was 0.175 ± 0.014, zeta potential was 10.1 ± 0.300 mV, encapsulation rate was 74.66 ± 0.671%, and drug loading capacity was 5.38 ± 0.316%. The stability of Cur-P-NPs was adequate, and the in vitro release rate increased with the decrease of the environmental pH. Seven days post incubation, the cumulative release values of Cur were 52.78%, 67.39%, and 98.12% at pH 7.4, pH 6.8 and pH 5.0, respectively. Cur-P-NPs exhibited better cell entry and antiproliferation efficacy against U251 cells than the Cur-solution and Cur-NPs and were safe for use. Cur-P-NPs specifically targeted tumor tissues and inhibited their growth (78.63% tumor growth inhibition rate) with low toxic effects on normal tissues.

Conclusion

The enzyme-targeted hybrid nanoparticles prepared in the study clearly have the tumor-targeting ability. Cur-P-NPs can effectively improve the bioavailability of Cur and have potential applications in drug delivery and tumor management.

Combination of Chemotherapy and Photodynamic Therapy with Oxygen Self-Supply in the Form of Mutual Assistance for Cancer Therapy

INTRODUCTION

Photodynamic therapy (PDT) has been widely researched by cancer therapists in recent years. This study aims to establish a drug delivery system combining PDT and chemotherapy to show that chemotherapeutic drugs provide oxygen to PDT, while PDT promotes the release of chemotherapeutic drug.

METHODS

Firstly, poly(ethylene glycol)-lysine(Ce6)-block-poly(L-glutamate)-imidazole (mPEG-lys(Ce6)-PGA-AIM) was synthesized and self-assembled into micelles that exhibited pH- and ROS-responsiveness and buffering capacity. Perfluorohexanoate-modified cisplatin (FCP), as oxygen carriers, was encapsulated into mPEG-lys(Ce6)-PGA-AIM micelles. Then, the properties of micelles and their biological functions in vivo and in vitro were investigated.

RESULTS

The micelles exhibited remarkabe stability, pH regulated drug release, good biocompatibility and effective tumor penetration. Cellular uptake demonstrated the efficient endosome/lysosome escape of CFMs, which facilitates the intracellular drug release. Both in vitro and in vivo experiments reflected that CFMs with laser irradiation showed significantly improved therapeutic activity compared with single PDT or chemotherapy.

CONCLUSION

Chemotherapy and PDT were combined in the form of mutual assistance to provide a promising strategy for clinical treatment.

Immobilising hairpin DNA-conjugated distyryl boron dipyrromethene on gold@polydopamine core-shell nanorods for microRNA detection and microRNA-mediated photodynamic therapy

A novel nanosystem of polydopamine-coated gold nanorods (AuNR@PDA) immobilised with molecules of hairpin DNA-conjugated distyryl boron dipyrromethene (DSBDP) was designed and fabricated for detection of microRNA-21 (miR-21). By using this oncogenic stimulus, the photodynamic effect of the DSBDP-based photosensitiser was also activated. In the presence of miR-21, the fluorescence intensity of the nanosystem was increased due to the dissociation of the conjugate from AuNR@PDA upon hybridisation. The intracellular fluorescence intensity triggered by intracellular miR-21 was in the order: MCF-7 > HeLa > HEK-293, which was in accordance with their miR-21 expression levels. The specificity was demonstrated by comparing the results with those of an analogue with a scrambled DNA sequence. The nanosystem could also result in miR-21-mediated photodynamic eradication of miR-21-overexpressed MCF-7 cells. After intravenous injection of the nanosystem into HeLa tumour-bearing nude mice, the fluorescence intensity of the tumour was increased over 24 h and was about 3-fold stronger than that of the scrambled analogue. Upon irradiation, the nanosystem could also greatly reduce the size of the tumour without causing significant tissue damage in the major organs. The overall results showed that this nanoplatform can serve as a specific and potent theranostic agent for simultaneous miR-21 detection and miR-21-mediated photodynamic therapy.

Nano-Strategies for Improving the Bioavailability of Inhaled Pharmaceutical Formulations

Pulmonary pharmaceutical formulations are targeted for the treatment of respiratory diseases. However, their application is limited due to the physiological characteristics of the lungs, such as branching structure, mucociliary and macrophages, as well as certain properties of the drugs like particle size and solubility. Nano-formulations can ameliorate particle sizes and improve drug solubility to enhance bioavailability in the lungs. The nano-formulations for lungs reviewed in this article can be classified into nanocarriers, no-carrier-added nanosuspensions and polymer-drug conjugates. Compared with conventional inhalation preparations, these novel pulmonary pharmaceutical formulations have their own advantages, such as increasing drug solubility for better absorption and less inflammatory reaction caused by the aggregation of insoluble drugs; prolonging pulmonary retention time and reducing drug clearance; improving the patient compliance by avoiding multiple repeated administrations. This review will provide the reader with some background information for pulmonary drug delivery and give an overview of the existing literature about nano-formulations for pulmonary application to explore nano-strategies for improving the bioavailability of pulmonary pharmaceutical formulations.

Phthalocyanine-Conjugated Glyconanoparticles for Chemo-photodynamic Combination Therapy

Combination cancer therapy based on multifunctional nanomaterials has attracted great attention. The present work focuses on the preparation of the glycopolymeric nanoparticle, which contains a photosensitizer (zinc(II)phthalocyanine, ZnPc) and an anticancer drug (Doxorubicin, Dox). First, a novel mono azide-functional ZnPc-N₃ with seven hydrophilic ethylene oxide chains was synthesized. Next, ZnPc alone or together with Dox bearing glycopolymers was synthesized via the RAFT polymerization method and then self-assembled into glyconanoparticles (GNPs) with narrow particle size distribution. Then the evaluation of the biological activity of GNPs (GNPs-ZnPc and GNPs-ZnPc/Dox) for dual photodynamic therapy (PDT) and chemotherapy against human breast cancer cells was investigated. The constructed GNPs were identified via general characterization methods, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). The prepared GNPs-ZnPc/Dox demonstrated remarkable photophysical and photochemical properties, involving good colloidal stability in biological conditions, pH-responsive drug release, and the capacity to generate singlet oxygen under light irradiation. The outer layer of nanoparticles covered by fructose sugar moieties achieves a targeted cancer therapy owing to GLUT5 (a well-known fructose transporter) overexpression toward breast cancer cells. In vitro experiments were then performed to evaluate the chemo/phototoxicity, cellular uptake, and anticancer efficacy of GNPs-ZnPc/Dox. In comparison with free Dox, human breast cancer cells treated with GNPs-ZnPc/Dox exhibited a higher cellular internalization via GLUT5 targeting. In particular, the GNPs-ZnPc/Dox nanoplatform revealed an excellent synergistic anticancer activity in comparison with free ZnPc-N₃ and free Dox, representing a novel and promising chemo-photodynamic combination therapeutic methodology to improve therapeutic efficacy.

Targeting Hypoxic Tumors with Hybrid Nanobullets for Oxygen-Independent Synergistic Photothermal and Thermodynamic Therapy

Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment. Herein, we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the "precise strike" of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid (HA) and hypoxia-dependent factor carbonic anhydrase IX (CA IX)-inhibitor acetazolamide (AZ). The core of nanobullets is the special zinc (II) phthalocyanine aggregates (ZPA) which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy (PTT), along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy (TDT). The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional (reactive oxygen species (ROS)-mediated) cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.

A nanoplatform based on mesoporous silica-coated gold nanorods for cancer triplex therapy

To enhance the efficacy of nanoparticle-based cancer therapy with reduced side effects and promote its clinical translation, a biocompatible nanocomposite based on mesoporous silica-coated gold nanorods (AuNR@MSN) for triple tumor therapy is reported in this study. The gold core served as a hyperthermia agent, while the MSN shell acted as a reservoir of chemotherapeutics owing to its excellent loading capacity. Cytochrome c with the apoptosis inducing function was anchored on the surface of AuNR@MSN to prevent drug leakage through redox-responsive disulfide bonds. The successful construction of a nanocomposite was confirmed by characterization of the physicochemical properties. In vitro and in vivo studies demonstrated that the nanocomposite displayed an optimizing anti-tumor effect with a synergistic strategy of excellent photothermal therapy, chemotherapy and protein therapy. Therefore, this cooperative strategy paves the way for high-efficiency oncotherapy with reduced side effects.

Nuclear-targeted nanocarriers based on pH-sensitive amphiphiles for enhanced GNA002 delivery and chemotherapy

GNA002, a novel EZH2 inhibitor, exhibits significant anticancer efficiency in solid malignant tumor therapy; however, its poor water solubility and low enrichment at tumor sites limit its clinical application and translation. In this study, an original pH-sensitive nanocarrier (cyclo (RGDyCSH) (cRGD)-poly (ethylene glycol) (PEG)-hydrazine (Hyd)-hexa-arginine (R6)-stearic acid (SA)) was designed to precisely deliver GNA002 into the nuclei of cancer cells. The PEG-modified hydrophilic shell of the spherical GNA002-loaded nanoparticles with a mean size of 143.13 ± 0.20 nm effectively facilitated the passive target of tumor tissues and prolonged the blood circulation time. Meanwhile, cRGD was used as the active targeting ligand, which promoted the accumulation of the nanoparticles in cancer cells via ανβ3-receptor-mediated endocytosis. Furthermore, the acidic environment of lysosomes triggered the rupture of the pH-sensitive hydrazine bond and the rapid formation of penetrating peptide R6-shelled secondary nanoparticles, thus enabling the lysosomal escape of the nanoparticles and the ultimate R6-mediated nuclear-targeted delivery of GNA002. Consequently, the nuclear-enriched GNA002 effectively enhanced the cytotoxicity against cancer cells both in vitro and in vivo, thus providing an original and promising drug delivery system for the targeted delivery of GNA002.

Facile preparation of multi-stimuli-responsive degradable hydrogels for protein loading and release

Functional materials that can recognize the tumor microenvironment, characterized by acidic or reducing conditions, are needed for the designing of drug delivery carriers for cancer treatment. Hydrogels are potential protein drug carriers because they contain a large amount of water and stimuli-responsive functions can easily be introduced in them. However, it is difficult to introduce multi-stimuli-responsive functions and degradability at the same time. Here, we synthesized thermo- and pH-responsive hydrogels via a coupling reaction between poly(ethylene glycol) diglycidyl ether (PEGDE) and cystamine (CA). The prepared hydrogels showed lower critical solution temperature-type thermoresponsive behavior and pH-responsive swelling changes due to the protonation of secondary and/or tertiary amino groups arising from the crosslinking agent CA. Under reducing conditions, the hydrogels were degraded via the thiol exchange reaction in the presence of dithiothreitol or glutathione. The loading and release properties of FITC-labeled model proteins from the hydrogels were investigated. The loaded amount of the protein increased with decreasing molecular weight or hydrodynamic radius, which is based on the size of the network structure of the hydrogels. Notably, loaded proteins in the hydrogels were released only under reducing conditions, which mimic the tumor microenvironment. Thus, the prepared multi-responsive degradable hydrogels are expected to be used as functional drug delivery carriers for cancer treatment.

The application of aluminium phthalocyanine AlPs-4-mediated photodynamic therapy against human soft tissue sarcoma (RMS) cell line

The main challenge in the cancer treatment is the on-target drug delivery to the affected cells. Various therapies have been designed to target the affected cells efficiently but still the success is awaited. An iron and cobalt nanocomposite for the effective drug delivery to target cells was designed. The photodynamic effect of anticancer drugs loaded with iron oxide and cobalt ferrite nanomaterials coated with polyvinyl alcohol (PVA) was studied. The iron oxide nanoparticles (IONPs) and cobalt ferrite (CF) NPs without the loaded drugs were characterized by UV, XRD, FTIR, SEM and EDX techniques. The photodynamic effect of the photosensitizer, doxorubicin, and dacarbazine loaded nanomaterials were screened against human rhabdomyosarcoma (RMS) cells after incubation for 3 h, 24 h, and 48 h using MTT assay. The combination of photodynamic therapy (PDT) with chemo drugs is studied over different doses. When RMS cells were exposed to nanomaterials loaded with chemo drugs and PDT alone, it resulted in less cell killing compared to chemo drugs followed by PDT. These results revealed that in the case of combined treatment (combination therapy) the cell viability decreases as compared to individual treatment (monotherapy). The in vitro studies showed positive results which give a new pathway for the in vivo studies.

Amphiphilic block polymer-based self-assembly of high payload nanoparticles for efficient combinatorial chemo-photodynamic therapy

Combinatorial chemo-photodynamic therapy is regared as effective cancer therapy strategy, which could be realized via multiple nano-drug delivery system. Herein, novel high payload nanoparticles stabilized by amphiphilic block polymer cholesterol-b-poly(ethylene glycol) (PEG)₂₀₀₀ (Chol-PEG₂₀₀₀) were fabricated for loading chemotherapeutic drug 10-hydroxycamptothecin (HCPT) and photosensitizer chlorin e6 (Ce6). The obtained HCPT/Ce6 NPs showed uniform rod-like morphology with a hydration diameter of 178.9 ± 4.0 nm and excellent stability in aqueous solution. HCPT and Ce6 in the NPs displayed differential release profile, which was benefit for preferentially exerting the photodynamic effect and subsequently enhancing the sensitivity of the cells to HCPT. Under laser irradiation, the NPs demonstrated fantastic in vitro and in vivo anticancer efficiency due to combinational chemo-photodynamic therapy, enhanced cellular uptake effectiveness, and superb intracellular ROS productivity. Besides, the NPs were proved as absent of systemic toxicity. In summary, this nanoparticle delivery system could be hopefully utilized as effective cancer therapy strategy for synergistically exerting combined chemo-photodynamic therapy in clinic.

Combined pH-responsive chemotherapy and glutathione-triggered photosensitization to overcome drug-resistant hepatocellular carcinoma — a SPP/JPP Young Investigator Award paper

Doxorubicin (DOX) resistance, which results in a reduced accumulation of DOX in the nucleus and hence decreased DNA damage, is a major challenge for chemotherapy against hepatocellular carcinoma. In this paper, we combined chemotherapy with photodynamic therapy (PDT) to combat DOX-resistant human hepatocellular carcinoma cells. We have prepared the polymeric micelles conjugating with DOX and zinc(II) phthalocyanine (ZnPc) through a pH-responsive hydrazone linker and a glutathione (GSH)-responsive disulfide linker, respectively. The polymeric micelles (DOX-ZnPc-micelles) exhibited a spherical shape with a size of about 98 nm diameter and showed excellent stability in aqueous solution. Due to the self-quenching of the ZnPc inside the micelles, DOX-ZnPc-micelles did not emit fluorescence upon red light irradiation. Drug release experiments verified that DOX and ZnPc could be released under acidic conditions and reducing environments, respectively. A higher concentration of DOX was internalized into DOX-resistant R-HepG2 cells through the delivery of polymeric micelles when compared with the free DOX, hence DOX-ZnPc-micelles exhibited a significant enhancement in anticancer activity. The IC[Formula: see text] value of DOX against R-HepG2 cells was found to be 21 [Formula: see text]M when combined with PDT and it was 5-fold less than that of a single treatment of DOX (102 [Formula: see text]M). The DOX-ZnPc-micelles could induce cell apoptosis and necrosis on R-HepG2 cells by combined therapeutic modalities, while these micelles induced only apoptosis on HepG2 cells. We have demonstrated that utilization of polymeric micelles can significantly enhance the cellular uptake and cytotoxicity of DOX against R-HepG2 cells when compared with free DOX. Moreover, PDT can act as an adjuvant therapeutic modality and combine with chemotherapy to further improve therapeutic efficacy. Overall speaking, DOX-ZnPc-micelles can overcome DOX resistance and induce a synergistic therapeutic effect against DOX-resistant R-HepG2 cells, hence improving the therapeutic efficacy when compared with monotherapy.

Multifunctional nanoparticles as photosensitizer delivery carriers for enhanced photodynamic cancer therapy

Photodynamic therapy (PDT) is an emerging cancer treatment combining light, oxygen, and a photosensitizer (PS) to produce highly cytotoxic reactive oxygen species that cause cancer cell death. However, most PSs are hydrophobic molecules that have poor water solubility and cannot target tumor tissues, causing damage to normal tissues and cells during PDT. Thus, there is a substantial demand for the development of nanocarrier systems to achieve targeted delivery of PSs into tumor tissues and cells. This review summarizes the research progress in PS delivery systems for PDT treatment of tumors and focuses on the recent design and development of multifunctional nanoparticles as PS delivery carriers for enhanced PDT. These multifunctional nanoparticles possess unique properties, including tunable particle size, changeable shape, stimuli-responsive PS activation, controlled PS release, and hierarchical targeting capability. These properties can increase tumor accumulation, penetration, and cellular internalization of nanoparticles to achieve PS activation and/or release in cancer cells for enhanced PDT. Finally, recent developments in multifunctional nanoparticles for tumor-targeted PS delivery and their future prospects in PDT are discussed.

Photo-triggered self-destructive ROS-responsive nanoparticles of high paclitaxel/chlorin e6 co-loading capacity for synergetic chemo-photodynamic therapy

To improve the anti-cancer therapeutic effect of nanosystems for chemo-photodynamic therapy, there remain several hurdles to be addressed, e.g., limited co-loading efficiency, insufficient stimulus-responsiveness and lack of synergetic effect. This work reported novel reactive‑oxygen-species (ROS)-responsive chlorin e6 (Ce6) and paclitaxel (PTX) co-encapsulated chondroitin sulfate-g-poly (propylene sulfide) nanoparticles (CP/ChS-g-PPS NPs), wherein the drug loading efficiencies of Ce6 and PTX were as high as 14.93% and 24.31%, respectively. To enlarge the ROS signal at tumor sites thus enhancing the ROS-responsiveness of ChS-g-PPS NPs, near-infrared (NIR) light was utilized to induce Ce6 to produce more ROS to destruct the NPs. Our data showed that the photo-triggered self-destructive property of NPs helped drugs to spread deeper in tumors upon laser irradiation, making the NPs promising to thoroughly remove tumor cells. CP/ChS-g-PPS NPs exhibited a synergetic chemo-photodynamic therapy effect in vitro, which was suggested by the combination indexes of PTX and Ce6 lower than 1 when 20-80% inhibition rates of MCF-7 cells were achieved. As for the in vivo antitumor activity, the tumor inhibition rates of CP/ChS-g-PPS NPs (with laser irradiation) were as high as 92.76% and 88.57% in 4T1 bearing BALB/c mice and MCF-7 bearing BALB/c nude mice, respectively, which were significantly higher than those of other treatment groups. This work provided a simple yet effective strategy to develop photo-triggered ROS-responsive NPs for synergetic chemo-photodynamic therapy with quick ROS-responsive self-destruction, spatiotemporally controllability, reduced off-target toxicity, and desirable therapeutic effect.